Artículos de revistas: "VCDL"

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Majek, Cedric, Pierre-Olivier Lucas De Peslouan, André Mariano, Hervé Lapuyade, Yann Deval y Jean-Baptiste Bégueret. "Voltage Controlled Delay Line with Phase Quadrature Outputs for [0.9-4]GHz Factorial Delay Locked Loop Dedicated to Zero-IF Multi-Standard Local Oscillator". Journal of Integrated Circuits and Systems 5, n.º 1 (21 de noviembre de 2010): 23–32. http://dx.doi.org/10.29292/jics.v5i1.307.

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This paper presents the design and the measurement results of a novel Voltage Controlled DelayLine (VCDL) dedicated to an original architecture of Delay Locked Loop (DLL): the Factorial DelayLocked Loop (F-DLL). Based on the multiphase ring oscillator technique, the proposed VCDL offers,among others, two outputs in phase quadrature. These last ones allow the F-DLL to be zero-IF compliantand becomes a good candidate for multi-standard local oscillator. The proposed circuit hasbeen fabricated in a 130nm CMOS-SOI technology from STMicroelectronics. Measurement resultsconfirm the low quadrature phase error of the topology (inferior to 5°) and the ability of the F-DLL tosynthesize the [0.9-4] GHz band, being suited for GSM up to WIMAX applications, while offering veryinteresting performances in term of phase noise and settling time.

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Chuang, Chi-Nan y Chun-Yen Wu. "A small area DLL-based clock generator using duty cycle controllable cyclic VCDL". International Journal of Electronics Letters 8, n.º 4 (9 de junio de 2019): 380–88. http://dx.doi.org/10.1080/21681724.2019.1625963.

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Xin, Tian, Liu Xiangxin y Li Wenhong. "A dual VCDL DLL based gate driver for zero-voltage-switching DC-DC converter". Journal of Semiconductors 31, n.º 7 (julio de 2010): 075012. http://dx.doi.org/10.1088/1674-4926/31/7/075012.

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Sofimowloodi, Sobhan, Farhad Razaghian y Mohammad Gholami. "A low-jitter clock multiplier using a simple low-power ECDLL with extra settled delays in VCDL". Analog Integrated Circuits and Signal Processing 102, n.º 3 (4 de febrero de 2020): 541–54. http://dx.doi.org/10.1007/s10470-020-01597-x.

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Seung-Jun Bae, Hyung-Joon Chi, Young-Soo Sohn y H. J. Park. "A VCDL-based 60-760-MHz dual-loop DLL with infinite phase-shift capability and adaptive-bandwidth scheme". IEEE Journal of Solid-State Circuits 40, n.º 5 (mayo de 2005): 1119–29. http://dx.doi.org/10.1109/jssc.2005.845989.

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Suman, Shruti, K. G. Sharma y P. K. Ghosh. "250 MHz Multiphase Delay Locked Loop for Low Power Applications". International Journal of Electrical and Computer Engineering (IJECE) 7, n.º 6 (1 de diciembre de 2017): 3323. http://dx.doi.org/10.11591/ijece.v7i6.pp3323-3331.

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Delay locked loop is a critical building block of high speed synchronous circuits. An improved architecture of amixed signaldelay locked loop (DLL) is presented here. In this DLL, delay cell based on single ended differential pair configuration is used for voltage controlled delay line (VCDL) implementation. This delay cell provides a high locking range with less phase noise and jitter due to differential pair configuration.For increasing the acquisition range and locking speed of the DLL, modified true single phase clock (TSPC) based phase frequency detector is used. The proposed design is implemented at 0.18 um CMOS technology and at power supply of 1.8V . It has power consumption of 1.39 mW at 125 MHz center frequency with locking range from 0.5 MHz to 250 MHz.

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Kawamoto, Takashi, Kazuhiro Ueda y Takayuki Noto. "480 MHz 10-tap Clock Generator Using Edge-Combiner DLL for USB 2.0 Applications". Journal of Electrical and Computer Engineering 2012 (2012): 1–17. http://dx.doi.org/10.1155/2012/267247.

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A clock generator with an edge-combiner DLL (ECDLL) has been developed for USB 2.0 applications. The clock generator generates 480 MHz 10-tap output signals from a 12 MHz reference signal and consists of three DLLs to shrink the design area so that it is smaller than a conventional one based on a PLL. Each DLL is applied to our proposed shot pulse reset technique to prevent from a harmonic lock and is applied to a voltage-controlled delay line (VCDL) with a trimming function to operate against any process voltage temperature (PVT) variations. A 90 nm CMOS process was used to fabricate our proposed clock generator. The 480 MHz 10-tap output signals satisfy the USB 2.0 specifications. A power consumption is less than 1.3 mW and a locking time is less than 3.5 μs, which are far less than a conventional one, 10.0 μs. The design area is200×225 μm, which is half that of the conventional one.

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LEE, Jae-seung, Jae-Yoon SIM y Hong June PARK. "A High-Throughput On-Chip Variation Monitoring Circuit for MOSFET Threshold Voltage Using VCDL and Time-to-Digital Converter". IEICE Transactions on Electronics E93-C, n.º 8 (2010): 1333–37. http://dx.doi.org/10.1587/transele.e93.c.1333.

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Kumar, V. Vinod y M. Meenakshi. "Tunable Low Power UWB Transmitter for WBAN Application". Journal of Circuits, Systems and Computers 24, n.º 03 (10 de febrero de 2015): 1550040. http://dx.doi.org/10.1142/s0218126615500401.

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This paper presents the design and simulation results for a Federal Communication Committee (FCC) complaint current starved delay line based Ultra Wide Band (UWB) Gaussian pulse transmitter, which is designed for operating in the 3.1–10.6 GHz range. The wavelet is a mono cycle Gaussian impulse wave, which is practically well suited for low cost, low power, low data rate wireless data transfer such as in wireless body area network (WBAN) applications. The transmitter operating frequency and bandwidth (BW) is controlled using a dc voltage provided at the input stage of a voltage controlled delay line (VCDL) and this aspect can be exploited for increasing the communication coverage area without compromising on the power consumption. A Gaussian wave shaping is performed for FCC compliance and the simulation has been carried out with 130 nm technology. The simulation of our design suggests an average dynamic power consumption of 1.11 mw for an energy efficiency of 14.2 pJ/pulse. The proposed IR-UWB transmitter design though a bit inferior in terms of the power efficiency, can claim superior performance with respect to tuning the BW, which is very relevant in a cognitive wireless networking scenario with other interfering signals.

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Holland, Benjamin H. y Robert J. Applegate. "Femoral Closure – Devices and Strategies in 2010". Interventional Cardiology Review 5, n.º 1 (2010): 93. http://dx.doi.org/10.15420/icr.2010.5.1.93.

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Vascular closure devices (VCDs) reduce the time to haemostasis and ambulation and improve patient comfort compared with manual compression in patients undergoing vascular procedures from a femoral artery access site. Recent large, single-centre studies andpost hocdata from the Acute Catheterization and Urgent Intervention Triage strategY (ACUITY) trial strongly suggest that newer generations of VCD decrease rates of vascular complications compared with manual compression, in contrast to earlier evaluations of first-generation devices. Unfortunately, utilisation of VCDs remains limited and mitigates the potential benefit that could result from expanded use of these devices. Newer entrants into the VCD market such as Starclose and Mynx are based on extravascular closure methodology. These devices address concerns of intravascular components of a VCD; however, whether these devices reduce vascular complications and bleeding has not been evaluated. In this brief article, we will examine these factors in greater detail and suggest an algorithm for VCD use in clinical practice.

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Fioletov, Vitali E., Chris A. McLinden, Alexander Cede, Jonathan Davies, Cristian Mihele, Stoyka Netcheva, Shao-Meng Li y Jason O'Brien. "Sulfur dioxide (SO2) vertical column density measurements by Pandora spectrometer over the Canadian oil sands". Atmospheric Measurement Techniques 9, n.º 7 (14 de julio de 2016): 2961–76. http://dx.doi.org/10.5194/amt-9-2961-2016.

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Abstract. Vertical column densities (VCDs) of SO2 retrieved by a Pandora spectral sun photometer at Fort McKay, Alberta, Canada, from 2013 to 2015 were analysed. The Fort McKay site is located in the Canadian oil sands region, approximately 20 km north of two major SO2 sources (upgraders), with total emission of about 45 kt yr−1. Elevated SO2 VCD values were frequently recorded by the instrument, with the highest values of about 9 Dobson Units (DU; DU = 2.69 × 1016 molecules cm−2). Comparisons with co-located in situ measurements demonstrated that there was a very good correlation between VCDs and surface concentrations in some cases, while in other cases, elevated VCDs did not correspond to high surface concentrations, suggesting the plume was above the ground. Elevated VCDs and surface concentrations were observed when the wind direction was from south to southeast, i.e. from the direction of the two local SO2 sources. The precision of the SO2 measurements, estimated from parallel measurements by two Pandora instruments at Toronto, is 0.17 DU. The total uncertainty of Pandora SO2 VCD, estimated using measurements when the wind direction was away from the sources, is less than 0.26 DU (1σ). Comparisons with integrated SO2 profiles from concurrent aircraft measurements support these estimates.

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Itahashi, S., I. Uno, H. Irie, J. Kurokawa y T. Ohara. "Trend analysis of tropospheric NO2 column density over East Asia during 2000–2010: multi-satellite observations and model simulations with the updated REAS emission inventory". Atmospheric Chemistry and Physics Discussions 13, n.º 4 (25 de abril de 2013): 11247–68. http://dx.doi.org/10.5194/acpd-13-11247-2013.

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Abstract. Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to surface NOx emissions and can thus be used to estimate the latter. In this study, the NO2 VCDs simulated by a regional chemical transport model with data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated by comparison with multi-satellite observations (GOME, SCIAMACHY, GOME-2, and OMI) between 2000 and 2010. Rapid growth in NO2 VCD driven by expansion of anthropogenic NOx emissions was revealed above the central eastern China region, except during the economic downturn. In contrast, slightly decreasing trends were captured above Japan. The modeled NO2 VCDs using the updated REAS emissions reasonably reproduced the annual trends observed by multi-satellites, suggesting that the NOx emissions growth rate estimated by the updated inventory is robust. On the basis of the close linear relationship of modeled NO2 VCD, observed NO2 VCD, and anthropogenic NOx emissions, the NOx emissions in 2009 and 2010 were estimated. It was estimated that the NOx emissions from anthropogenic sources in China beyond doubled between 2000 and 2010, reflecting the strong growth of anthropogenic emissions in China with the rapid recovery from the economic downturn during late 2008 and mid-2009.

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13

Halla, J. D., T. Wagner, S. Beirle, J. R. Brook, K. L. Hayden, J. M. O'Brien, A. Ng, D. Majonis, M. O. Wenig y R. McLaren. "Determination of tropospheric vertical columns of NO2 and aerosol optical properties in a rural setting using MAX-DOAS". Atmospheric Chemistry and Physics Discussions 11, n.º 4 (27 de abril de 2011): 13035–97. http://dx.doi.org/10.5194/acpd-11-13035-2011.

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Abstract. Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements were performed in a rural location of southwestern Ontario during the Border Air Quality and Meteorology Study. Slant column densities (SCDs) of NO2 and O4 were determined using the standard DOAS technique. Using a radiative transfer model and the O4 SCDs, aerosol optical depths were determined for clear sky conditions and compared to OMI, MODIS, AERONET, and local PM2.5 measurements. This aerosol information was input to a radiative transfer model to calculate NO2 air mass factors, which were fit to the measured NO2 SCDs to determine tropospheric vertical column densities (VCDs) of NO2. The method of determining NO2 VCDs in this way was validated by comparison to composite VCDs derived from aircraft and ground-based measurements of NO2. The new VCDs were compared to VCDs of NO2 determined via the satellite instruments SCIAMACHY and OMI, for overlapping time periods. The satellite-derived VCDs were higher by 50%, with a mean positive error of 0.5–0.9 × 1015 molec cm−2. This last finding is different from previous studies whereby MAX-DOAS geometric VCDs were higher than satellite determinations, albeit for urban areas with higher VCDs. An effective boundary layer height, BLeff, is defined as the ratio of the tropospheric VCD and the ground level concentration of NO2. Variations of BLeff can be linked to time of day, source region, stability of the atmosphere, and the presence or absence of elevated NOx sources. In particular, a case study is shown where a high VCD and BLeff were observed when an elevated industrial plume of NOx and SO2 was fumigated to the surface as a lake breeze front impacted the measurement site. High BLeff values (~1.9 km) were observed during a regional smog event when high winds from the SW and high convection promoted mixing throughout the boundary layer. During this event, the regional line flux of NO2 through the region was estimated to be greater than 112 kg NO2 km−1 h−1.

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Halla, J. D., T. Wagner, S. Beirle, J. R. Brook, K. L. Hayden, J. M. O'Brien, A. Ng, D. Majonis, M. O. Wenig y R. McLaren. "Determination of tropospheric vertical columns of NO2 and aerosol optical properties in a rural setting using MAX-DOAS". Atmospheric Chemistry and Physics 11, n.º 23 (13 de diciembre de 2011): 12475–98. http://dx.doi.org/10.5194/acp-11-12475-2011.

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Abstract. Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements were performed in a rural location of southwestern Ontario during the Border Air Quality and Meteorology Study. Slant column densities (SCDs) of NO2 and O4 were determined using the standard DOAS technique. Using a radiative transfer model and the O4 SCDs, aerosol optical depths were determined for clear sky conditions and compared to OMI, MODIS, AERONET, and local PM2.5 measurements. This aerosol information was input to a radiative transfer model to calculate NO2 air mass factors, which were fit to the measured NO2 SCDs to determine tropospheric vertical column densities (VCDs) of NO2. The method of determining NO2 VCDs in this way was validated for the first time by comparison to composite VCDs derived from aircraft and ground-based measurements of NO2. The new VCDs were compared to VCDs of NO2 determined via retrievals from the satellite instruments SCIAMACHY and OMI, for overlapping time periods. The satellite-derived VCDs were higher, with a mean bias of +0.5–0.9×1015 molec cm−2. This last finding is different from previous studies whereby MAX-DOAS geometric VCDs were higher than satellite determinations, albeit for urban areas with higher VCDs. An effective boundary layer height, BLHeff, is defined as the ratio of the tropospheric VCD and the ground level concentration of NO2. Variations of BLHeff can be linked to time of day, source region, stability of the atmosphere, and the presence or absence of elevated NOx sources. In particular, a case study is shown where a high VCD and BLHeff were observed when an elevated industrial plume of NOx and SO2 was fumigated to the surface as a lake breeze impacted the measurement site. High BLHeff values (~1.9 km) were observed during a regional smog event when high winds from the SW and high convection promoted mixing throughout the boundary layer. During this event, the regional line flux of NO2 through the region was estimated to be greater than 112 kg NO2 km−1 h−1.

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Ma, J. Z., S. Beirle, J. L. Jin, R. Shaiganfar, P. Yan y T. Wagner. "Tropospheric NO2 vertical column densities over Beijing: results of the first three-years of ground-based MAX-DOAS measurements (2008–2011) and satellite validation". Atmospheric Chemistry and Physics Discussions 12, n.º 10 (11 de octubre de 2012): 26719–81. http://dx.doi.org/10.5194/acpd-12-26719-2012.

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Abstract. Ground-based measurements of scattered sunlight by the Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) have been carried out at an urban site (39.95° N, 116.32° E) in Beijing megacity since 6 August 2008. In this study, we retrieved the tropospheric NO2 vertical column densities (VCDs) over Beijing from these MAX-DOAS observations from August 2008 to September 2011. Over such period, the daytime (08:00–17:00 h Beijing Time) mean tropospheric NO2 VCDs varied from 0.5 to 13.3 with an average of 3.6 during summertime, and from 0.2 to 16.8 with an average of 5.8 during wintertime, all in units of 1016 molecules cm−2. The average diurnal variation patterns of tropospheric NO2 over Beijing appeared to be rather different from one season to another, indicating differences in the mixing layer height, the atmospheric lifetime and the emission patterns. In contrast to previous studies, we find a small weekly cycle of the tropospheric NO2 VCD over Beijing. The NO2 VCD in the late afternoon was the largest on Saturday and the lowest on Sunday, and in the morning it reached a clear maximum on Wednesday. We also find a post Olympic Games effect, with 39–54% decrease in the tropospheric NO2 VCD over Beijing estimated for August of 2008, compared to the following years. The tropospheric NO2 VCDs derived by our ground MAX-DOAS measurements show a good correlation with SCIAMACHY and OMI satellite data. However, compared with the MAX-DOAS measurements, the satellite observations underestimate the tropospheric NO2 VCDs over Beijing systematically, by 43% for SCIAMACHY and 26–38% for OMI (DOMINO v2.0 and DOMINO v1.02). Based on radiative transfer simulations, we show that the aerosol shielding effect can explain this underestimation, while the gradient smoothing effect caused by the coarse spatial resolution of the satellite observations could play an additional role.

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Ma, J. Z., S. Beirle, J. L. Jin, R. Shaiganfar, P. Yan y T. Wagner. "Tropospheric NO2 vertical column densities over Beijing: results of the first three years of ground-based MAX-DOAS measurements (2008–2011) and satellite validation". Atmospheric Chemistry and Physics 13, n.º 3 (7 de febrero de 2013): 1547–67. http://dx.doi.org/10.5194/acp-13-1547-2013.

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Abstract. Ground-based measurements of scattered sunlight by the Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) have been carried out at an urban site (39.95° N, 116.32° E) in Beijing megacity since 6 August 2008. In this study, we retrieved the tropospheric NO2 vertical column densities (VCDs) over Beijing from these MAX-DOAS observations from August 2008 to September 2011. Over this period, the daytime (08:00–17:00 Beijing Time (BJT, which equals UTC + 8)) mean tropospheric NO2 VCDs varied from 0.5 to 13.3 with an average of 3.6 during summertime, and from 0.2 to 16.8 with an average of 5.8 during wintertime, all in units of 1016 molecules cm−2. The average diurnal variation patterns of tropospheric NO2 over Beijing appeared to be rather different from one season to another, indicating differences in the emission strength and atmospheric lifetime. In contrast to previous studies, we find a small weekly cycle of the tropospheric NO2 VCD over Beijing. The NO2 VCD in the late afternoon was the largest on Saturday and the lowest on Sunday, and in the morning it reached a clear maximum on Wednesday. We also find a post-Olympic Games effect, with 39–54% decrease in the tropospheric NO2 VCD over Beijing estimated for August of 2008, compared to the following years. The tropospheric NO2 VCDs derived by our ground MAX-DOAS measurements show a good correlation with SCIAMACHY and OMI satellite data. However, compared with the MAX-DOAS measurements, the satellite observations underestimate the tropospheric NO2 VCDs over Beijing systematically, by 43% for SCIAMACHY and 26–38% for OMI (DOMINO v2.0 and DOMINO v1.02). Based on radiative transfer simulations, we show that the aerosol shielding effect can explain this underestimation, while the gradient smoothing effect caused by the coarse spatial resolution of the satellite observations could play an additional role.

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Mollee, Peter, John Reynolds, Wojt Janowski, Hang Quach, Philip Campbell, Simon D. Gibbs, Sophie Lee et al. "A Randomized Study of Bortezomib, Cyclophosphamide and Dexamethasone Induction (VCD) Versus VCD and Daratumumab Induction Followed By Daratumumab Maintenance (VCDD) for the Initial Treatment of Transplant-Ineligible Patients with Multiple Myeloma (AMaRC 03-16)". Blood 136, Supplement 1 (5 de noviembre de 2020): 4–5. http://dx.doi.org/10.1182/blood-2020-138394.

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Introduction Daratumumab, when added to standard of care regimens in relapsed and untreated myeloma, has consistently demonstrated significant improvements in response rates, induction of MRD negative responses and progression-free survival (PFS) while proving highly tolerable with minor increases in overall regimen toxicity. In non-transplant eligible patients daratumumab has been added in randomized studies to lenalidomide and dexamethasone (Rd) and bortezomib, melphalan and prednisolone (VMP) backbones, but not to the VCD regimen. Furthermore, the randomized studies excluded a significant proportion of patients with comorbidities so the benefit of daratumumab in a frail, elderly myeloma population remains untested. Methods Inclusion criteria included untreated patients with symptomatic myeloma who were considered ineligible for high-dose chemotherapy with autologous stem cell transplantation due to either age >65years or the presence of comorbidities. Any degree of renal impairment, including dialysis dependence, was allowed as were patients with a prior history of systemic malignancy that had been disease-free for 2 years. Patients were randomized 1:1 to receive VCD or VCDD. VCD consisted of nine 5-week cycles of V 1.3 mg/m2 SC on Days 1, 8, 15 and 22; C 300mg/m2 PO on Days 1, 8, 15 and 22 and D 20 mg PO on Days 1, 8, 15 and 22. VCDD consisted of nine 5-week cycles of VCD plus daratumumab 16 mg/kg IV on Days 1, 8, 15 and 22 of cycles 1 and 2, Days 1 and 15 of cycles 3 to 6 and Day 1 of cycles 7 to 9, followed by daratumumab maintenance 16 mg/kg IV every 4 weeks until progression. The primary endpoint was PFS with secondary endpoints being response rates, MRD, overall survival, toxicity and quality of life. Results A total of 129 patients were randomized, but 7 did not commence intended therapy. The following modified ITT analysis is based on the 122 randomized patients, 58 in the VCD group and 64 in the VCDD group, who received therapy. Baseline characteristics were balanced between the two arms. Median age was 76 years (range, 62-91yrs), with 19% being ≥80 years of age. 30% were female. ECOG performance status was 0 (34%),1 (26%), 2 (16%) and unknown (25%). ISS stage was I (16%), II (36%), III (23%) and unknown (24%). The estimated median potential follow-up is 12.6 months. At the time of this report, the COVID-19 pandemic had impacted collection of site data. As a result, the following outcome data is provisional with a full data set to be available for presentation of the formal pre-planned interim analysis by the time of the ASH meeting. Overall response rate was 86% for VCD and 93% for VCDD. There was no significant difference between response rates after 4 cycles of induction for the VCD and VCDD arms: CR 3% vs 2%, VGPR 31% vs 41%, PR 51% vs 50%, MR 11% vs 7%, PD 3% vs 0%. Median PFS for the entire cohort (Fig A) was 21.8 months (95%CI 17.1-31.6 months). Median PFS for those treated with VCD was 18.9 months (95%CI 15.3-NR) and was 26.3 months (95%CI 17.1-31.6 months) for those treated with VCDD. In both arms combined, median PFS was 26.3 vs 21.9 months for those aged <75 vs ≥75 yrs, and not reached, 21.8 months and 19.9 months for those with ISS stage I, II and III, respectively. 19% of patients in the VCD group and 16% of patients in the VCDD group ceased therapy early, predominantly due to adverse events or death. SAEs during the induction period occurred in 44% and 52% of patients in the VCD and VCDD arms, respectively. There were 13 patients with SAEs due to infection in the VCD group and 20 in the VCDD group. Grade 3 or 4 peripheral neuropathy was uncommon, with only one case in the VCD arm. Conclusions The VCD schedule as detailed in this study appears efficacious, well tolerated and deliverable to an elderly myeloma population. The addition of daratumumab does not compromise chemotherapy delivery and may improve PFS. Formal interim analysis of the trial data will be presented at the meeting. Figure 1 Disclosures Mollee: Amgen: Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Reynolds:Novartis AG: Current equity holder in publicly-traded company. Janowski:Janssen: Membership on an entity's Board of Directors or advisory committees; BMS/ Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; AstraZenica: Consultancy. Quach:Amgen, Celgene, karyopharm, GSK, Janssen Cilag, Sanofi.: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Honoraria; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Consultancy; Amgen, sanofi, celgene, Karyopharm, GSK: Research Funding. Campbell:Amgen, Novartis, Roche, Janssen, Celgene (BMS): Research Funding; AstraZeneca, Janssen, Roche, Amgen, CSL Behring, Novartis: Consultancy. Gibbs:Janssen, BMS/Celgene, Amgen, Takeda, Pfizer, Caelum, Abbvie and Eidos: Membership on an entity's Board of Directors or advisory committees. D'Rozario:Abbvie: Membership on an entity's Board of Directors or advisory committees; BMS/ Celgene: Membership on an entity's Board of Directors or advisory committees. Wallington-Beddoe:Amgen: Membership on an entity's Board of Directors or advisory committees. Weber:Amgen: Membership on an entity's Board of Directors or advisory committees. Spencer:Celgene, Janssen and Takeda: Speakers Bureau; AbbVie, Celgene, Haemalogix, Janssen, Sanofi, SecuraBio, Specialised Therapeutics Australia, Servier and Takeda: Consultancy; Amgen, Celgene, Haemalogix, Janssen, Servier and Takeda: Research Funding; AbbVie, Amgen, Celgene, Haemalogix, Janssen, Sanofi, SecuraBio, Specialised Therapeutics Australia, Servier and Takeda: Honoraria. OffLabel Disclosure: Daratumumab as initial treatment of myeloma

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Elmasri, Matthew A., Stephen T. Kee, John M. Moriarty, Antoinette Gomes, Edward W. Lee y Justin P. McWilliams. "Single-center comparison of the efficacy and complications of arterial vascular closure devices in interventional radiology". Journal of Vascular Access 18, n.º 4 (20 de junio de 2017): 339–44. http://dx.doi.org/10.5301/jva.5000623.

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Introduction Vascular closure devices (VCDs) are commonly used to achieve hemostasis of arterial access sites, but there is little comparative data on the variety of VCDs currently in clinical use. We reviewed the VCD experience at our institution to determine the safest and most effective VCD. Materials and Methods Retrospective analysis of 907 consecutive arterial procedures in interventional radiology from June 2012 to June 2014 was performed. Five VCDs were used: Angio-Seal (n = 478), FISH (n = 56), Mynx (n = 56), Perclose (n = 61), and Starclose (n = 68). Patients who underwent manual compression (n = 188) without use of VCDs were also studied as a comparison group. Patient demographics and pre-procedural laboratory parameters were recorded. The technical success rate for achievement of hemostasis and complication rates were noted. Results Complete hemostasis rate (aka technical success rate) was 93.5% for Angio-Seal, 83.9% for FISH, 53.6% for Mynx, 73.7% for Perclose, 76.5% for Starclose, and 91.5% for manual compression. The differences among the devices were statistically significant (p<0.001). Fourteen major complications (1.5%) were encountered: nine with Angio-Seal (1.9%), one with Mynx (1.8%), one with Starclose (1.5%), and three with manual compression (1.6%); these differences were not statistically significant. Of the demographic and laboratory parameters studied, none were significantly correlated with hemostasis failure or development of complications. Conclusions In our single-center institutional experience, Angio-Seal is the device with the best technical success rate. Major complications of VCDs were rare, with no statistically significant difference between devices.

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Zhao, Xiaoyi, Debora Griffin, Vitali Fioletov, Chris McLinden, Jonathan Davies, Akira Ogyu, Sum Chi Lee et al. "Retrieval of total column and surface NO2 from Pandora zenith-sky measurements". Atmospheric Chemistry and Physics 19, n.º 16 (22 de agosto de 2019): 10619–42. http://dx.doi.org/10.5194/acp-19-10619-2019.

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Abstract. Pandora spectrometers can retrieve nitrogen dioxide (NO2) vertical column densities (VCDs) via two viewing geometries: direct Sun and zenith sky. The direct-Sun NO2 VCD measurements have high quality (0.1 DU accuracy in clear-sky conditions) and do not rely on any radiative transfer model to calculate air mass factors (AMFs); however, they are not available when the Sun is obscured by clouds. To perform NO2 measurements in cloudy conditions, a simple but robust NO2 retrieval algorithm is developed for Pandora zenith-sky measurements. This algorithm derives empirical zenith-sky NO2 AMFs from coincident high-quality direct-Sun NO2 observations. Moreover, the retrieved Pandora zenith-sky NO2 VCD data are converted to surface NO2 concentrations with a scaling algorithm that uses chemical-transport-model predictions and satellite measurements as inputs. NO2 VCDs and surface concentrations are retrieved from Pandora zenith-sky measurements made in Toronto, Canada, from 2015 to 2017. The retrieved Pandora zenith-sky NO2 data (VCD and surface concentration) show good agreement with both satellite and in situ measurements. The diurnal and seasonal variations of derived Pandora zenith-sky surface NO2 data also agree well with in situ measurements (diurnal difference within ±2 ppbv). Overall, this work shows that the new Pandora zenith-sky NO2 products have the potential to be used in various applications such as future satellite validation in moderate cloudy scenes and air quality monitoring.

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20

MacKay-Lyons, Renée, Constantin Christopoulos y Michael Montgomery. "Viscoelastic Coupling Dampers for Enhanced Multiple Seismic Hazard Level Performance of High-Rise Buildings". Earthquake Spectra 34, n.º 4 (noviembre de 2018): 1847–67. http://dx.doi.org/10.1193/091616eqs151m.

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Viscoelastic coupling dampers (VCDs) are installed in lieu of traditional reinforced concrete (RC) coupling beams in high-rise buildings to provide distributed supplemental damping for all dynamic loading conditions without affecting the architectural layout. When distributed effectively over the height of the building, VCDs provide viscous damping in all lateral modes of vibration and an elastic restoring force that enhances the lateral stiffness of the coupled system. In this paper, a first extensive numerical case study is carried out to compare the seismic performance of a conventional coupled shear wall high-rise building to a high damping alternate of the same design in which VCDs replace all diagonal RC beams in the core to enhance its seismic resilience. The added damping from VCDs is intended to reduce the peak responses under low amplitude earthquakes, but for larger amplitude maximum credible earthquakes, the peak responses are similar; however, structural damage is greatly reduced. Three seismic hazard levels were investigated, and the results indicate that the use of VCDs reduces peak floor accelerations, story drifts, and story shears over all seismic intensities. Nonlinear time-history analysis results also highlighted the improved resilience of the VCD structure at the maximum credible seismic hazard level where the use of VCDs eliminated all damage to coupling beams that would otherwise require repair over most of the height of the building.

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21

Halim, J., L. Missault, M. Lycke y J. Van der Heyden. "Assessment of the MANTA closure device in transfemoral transcatheter aortic valve replacement: a single-centre observational study". Netherlands Heart Journal 28, n.º 12 (27 de julio de 2020): 639–44. http://dx.doi.org/10.1007/s12471-020-01465-3.

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Abstract Objectives The present study aims to evaluate the efficacy and safety of the MANTA vascular closure device (VCD) (Teleflex, Morrisville, NC, USA) in transfemoral transcatheter aortic valve replacement (TF-TAVR). Background To close the femoral artery in TF-TAVR a VCD is the treatment of choice. Data involving suture-based VCDs have been extensive. Although scarce, results on the MANTA device are promising. There is no consensus yet as to whether the MANTA device is associated with fewer access-site-related vascular/bleeding complications when compared to suture-based VCDs. Methods In this prospective single-arm study, performed at a single centre, a total of 73 patients eligible for TF-TAVR were included and consecutively treated with the MANTA device. Results Access-site-related vascular complications were seen in 13.7% of patients treated with the MANTA device. In this group of patients only minor vascular complications were observed. Access-site-related bleeding complications were rare (6.8%), and device failure was seen in 13.7% of the patients. Conclusions This single-centre study confirms that use of the MANTA device in TF-TAVR is feasible with an acceptable rate of access-site-related complications and no major vascular complications.

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22

Wang, Fang, Hua Su, Xiaoxia Wang, Qionghui Wu, Yong Zhou, Hangdi Xu y Ruifeng Zhang. "Pituitrin use is associated with an increased risk of inguinal hematomas and pseudoaneurysms in patients undergoing femoral artery puncture". Journal of International Medical Research 47, n.º 7 (23 de mayo de 2019): 2976–86. http://dx.doi.org/10.1177/0300060519849785.

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Objective Femoral artery puncture (FAP) is an effective method for interventional percutaneous vascular procedures. However, FAP leads to complications including hematomas and pseudoaneurysms. This study was performed to determine whether pituitrin infusion or vascular closure devices (VCDs) increase the risk of complications after FAP. Methods This single-center retrospective study included 3641 patients who underwent FAP. The patients were divided into two groups: a groin complication group (including hematomas and pseudoaneurysms) and a no-groin complication group. Results In the multivariate analysis, perioperative pituitrin infusion and the use of VCDs were strongly associated with inguinal hematomas and pseudoaneurysms. The complication rate was obviously higher in patients who underwent bronchial artery embolization (BAE). Because high dosages of pituitrin and VCDs were used in patients undergoing BAE, postoperative hematoma development occurred significantly earlier in these patients. Hematomas occurred within 14 days of the operation in all patients who underwent BAE. Conclusion Perioperative pituitrin infusion and the use of VCDs are associated with an increased risk of complications after FAP, including hematomas and pseudoaneurysms. Notably, patients who underwent BAE, who are subject to higher pituitrin and VCD use, showed a higher complication rate. The incidence of complications was highest within 2 weeks postoperatively.

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23

Fioletov, Vitali, Chris A. McLinden, Shailesh K. Kharol, Nickolay A. Krotkov, Can Li, Joanna Joiner, Michael D. Moran, Robert Vet, Antoon J. H. Visschedijk y Hugo A. C. Denier van der Gon. "Multi-source SO2 emission retrievals and consistency of satellite and surface measurements with reported emissions". Atmospheric Chemistry and Physics 17, n.º 20 (24 de octubre de 2017): 12597–616. http://dx.doi.org/10.5194/acp-17-12597-2017.

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Abstract. Reported sulfur dioxide (SO2) emissions from US and Canadian sources have declined dramatically since the 1990s as a result of emission control measures. Observations from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and ground-based in situ measurements are examined to verify whether the observed changes from SO2 abundance measurements are quantitatively consistent with the reported changes in emissions. To make this connection, a new method to link SO2 emissions and satellite SO2 measurements was developed. The method is based on fitting satellite SO2 vertical column densities (VCDs) to a set of functions of OMI pixel coordinates and wind speeds, where each function represents a statistical model of a plume from a single point source. The concept is first demonstrated using sources in North America and then applied to Europe. The correlation coefficient between OMI-measured VCDs (with a local bias removed) and SO2 VCDs derived here using reported emissions for 1° by 1° gridded data is 0.91 and the best-fit line has a slope near unity, confirming a very good agreement between observed SO2 VCDs and reported emissions. Having demonstrated their consistency, seasonal and annual mean SO2 VCD distributions are calculated, based on reported point-source emissions for the period 1980–2015, as would have been seen by OMI. This consistency is further substantiated as the emission-derived VCDs also show a high correlation with annual mean SO2 surface concentrations at 50 regional monitoring stations.

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24

Beirle, S., U. Platt, M. Wenig y T. Wagner. "Weekly cycle of NO2 by GOME measurements: a signature of anthropogenic sources". Atmospheric Chemistry and Physics 3, n.º 6 (16 de diciembre de 2003): 2225–32. http://dx.doi.org/10.5194/acp-3-2225-2003.

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Abstract. Nitrogen oxides (NO+NO2=NOx and reservoir species) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50% of the total production of NOx. Since human activity in industrialized countries largely follows a seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. By estimating and subtracting the stratospheric column, and considering radiative transfer, vertical column densities (VCD) of tropospheric NO2 can be determined (e.g. Leue et al., 2001). We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25-50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD may help to identify the different anthropogenic source categories. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle exemplarily over Germany, obtaining a value of about 6 h in summer and 18-24 h in winter.

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Tack, Frederik, Alexis Merlaud, Marian-Daniel Iordache, Thomas Danckaert, Huan Yu, Caroline Fayt, Koen Meuleman, Felix Deutsch, Frans Fierens y Michel Van Roozendael. "High-resolution mapping of the NO2 spatial distribution over Belgian urban areas based on airborne APEX remote sensing". Atmospheric Measurement Techniques 10, n.º 5 (4 de mayo de 2017): 1665–88. http://dx.doi.org/10.5194/amt-10-1665-2017.

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Abstract. We present retrieval results of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs), mapped at high spatial resolution over three Belgian cities, based on the DOAS analysis of Airborne Prism EXperiment (APEX) observations. APEX, developed by a Swiss-Belgian consortium on behalf of ESA (European Space Agency), is a pushbroom hyperspectral imager characterised by a high spatial resolution and high spectral performance. APEX data have been acquired under clear-sky conditions over the two largest and most heavily polluted Belgian cities, i.e. Antwerp and Brussels on 15 April and 30 June 2015. Additionally, a number of background sites have been covered for the reference spectra. The APEX instrument was mounted in a Dornier DO-228 aeroplane, operated by Deutsches Zentrum für Luft- und Raumfahrt (DLR). NO2 VCDs were retrieved from spatially aggregated radiance spectra allowing urban plumes to be resolved at the resolution of 60 × 80 m2. The main sources in the Antwerp area appear to be related to the (petro)chemical industry while traffic-related emissions dominate in Brussels. The NO2 levels observed in Antwerp range between 3 and 35 × 1015 molec cm−2, with a mean VCD of 17.4 ± 3.7 × 1015 molec cm−2. In the Brussels area, smaller levels are found, ranging between 1 and 20 × 1015 molec cm−2 and a mean VCD of 7.7 ± 2.1 × 1015 molec cm−2. The overall errors on the retrieved NO2 VCDs are on average 21 and 28 % for the Antwerp and Brussels data sets. Low VCD retrievals are mainly limited by noise (1σ slant error), while high retrievals are mainly limited by systematic errors. Compared to coincident car mobile-DOAS measurements taken in Antwerp and Brussels, both data sets are in good agreement with correlation coefficients around 0.85 and slopes close to unity. APEX retrievals tend to be, on average, 12 and 6 % higher for Antwerp and Brussels, respectively. Results demonstrate that the NO2 distribution in an urban environment, and its fine-scale variability, can be mapped accurately with high spatial resolution and in a relatively short time frame, and the contributing emission sources can be resolved. High-resolution quantitative information about the atmospheric NO2 horizontal variability is currently rare, but can be very valuable for (air quality) studies at the urban scale.

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Kumar, Vinod, Steffen Beirle, Steffen Dörner, Abhishek Kumar Mishra, Sebastian Donner, Yang Wang, Vinayak Sinha y Thomas Wagner. "Long-term MAX-DOAS measurements of NO2, HCHO, and aerosols and evaluation of corresponding satellite data products over Mohali in the Indo-Gangetic Plain". Atmospheric Chemistry and Physics 20, n.º 22 (23 de noviembre de 2020): 14183–235. http://dx.doi.org/10.5194/acp-20-14183-2020.

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Abstract. We present comprehensive long-term ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of aerosols, nitrogen dioxide (NO2), and formaldehyde (HCHO) from Mohali (30.667∘ N, 76.739∘ E; ∼310 m above mean sea level), located in the densely populated Indo-Gangetic Plain (IGP) of India. We investigate the temporal variation in tropospheric columns, surface volume mixing ratio (VMR), and vertical profiles of aerosols, NO2, and HCHO and identify factors driving their ambient levels and distributions for the period from January 2013 to June 2017. We observed mean aerosol optical depth (AOD) at 360 nm, tropospheric NO2 vertical column density (VCD), and tropospheric HCHO VCD for the measurement period to be 0.63 ± 0.51, (6.7 ± 4.1) × 1015, and (12.1 ± 7.5) × 1015 molecules cm−2, respectively. Concerning the tropospheric NO2 VCDs, Mohali was found to be less polluted than urban and suburban locations of China and western countries, but comparable HCHO VCDs were observed. For the more than 4 years of measurements during which the region around the measurement location underwent significant urban development, we did not observe obvious annual trends in AOD, NO2, and HCHO. High tropospheric NO2 VCDs were observed in periods with enhanced biomass and biofuel combustion (e.g. agricultural residue burning and domestic burning for heating). Highest tropospheric HCHO VCDs were observed in agricultural residue burning periods with favourable meteorological conditions for photochemical formation, which in previous studies have shown an implication for high ambient ozone also over the IGP. Highest AOD is observed in the monsoon season, indicating possible hygroscopic growth of the aerosol particles. Most of the NO2 is located close to the surface, whereas significant HCHO is present at higher altitudes up to 600 m during summer indicating active photochemistry at high altitudes. The vertical distribution of aerosol, NO2, and HCHO follows the change in boundary layer height (BLH), from the ERA5 dataset of European Centre for Medium-Range Weather Forecasts, between summer and winter. However, deep convection during the monsoon transports the pollutants at high altitudes similar to summer despite a shallow ERA5 BLH. Strong gradients in the vertical profiles of HCHO are observed during the months when primary anthropogenic sources dominate the formaldehyde production. High-resolution MODIS AOD measurements correlate well but were systematically higher than MAX-DOAS AODs. The ground-based MAX-DOAS measurements were used to evaluate three NO2 data products and two HCHO data products of the Ozone Monitoring Instrument (OMI) for the first time over India and the IGP. NO2 VCDs from OMI correlate reasonably with MAX-DOAS VCDs but are lower by ∼30 %–50 % due to the difference in vertical sensitivities and the rather large OMI footprint. OMI HCHO VCDs exceed the MAX-DOAS VCDs by up to 30 %. We show that there is significant scope for improvement in the a priori vertical profiles of trace gases, which are used in OMI retrievals. The difference in vertical representativeness was found to be crucial for the observed biases in NO2 and HCHO surface VMR intercomparisons. Using the ratio of NO2 and HCHO VCDs measured from MAX-DOAS, we have found that the peak daytime ozone production regime is sensitive to both NOx and VOCs in winter but strongly sensitive to NOx in other seasons.

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27

Beirle, S., U. Platt, M. Wenig y T. Wagner. "Weekly cycle of NO2 by GOME measurements: A signature of anthropogenic sources". Atmospheric Chemistry and Physics Discussions 3, n.º 4 (3 de julio de 2003): 3451–67. http://dx.doi.org/10.5194/acpd-3-3451-2003.

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Abstract. Nitrogen oxides (NO+NO2=NOx) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50\\% of the total production of NOx. Since human activity in industrialized countries largely follows an artificial seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. Applying sophisticated algorithms, vertical column densities (VCD) of tropospheric NO2 can be determined. We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25–50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD allows the identification of anthropogenic sources. In addition, the fraction of emissions subjected to a weekly cycle (mainly transport, power generation) with respect to a constant background (all kind of natural sources, biomass burning, heavy industry) can be estimated. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle over Germany in detail, obtaining a value of about 12 h.

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28

O'Leary, Robert, James E. Reilly, Hugo H. Hanson, Semie Kang, Nicole Lou y Greg R. Phillips. "A variable cytoplasmic domain segment is necessary for γ-protocadherin trafficking and tubulation in the endosome/lysosome pathway". Molecular Biology of the Cell 22, n.º 22 (15 de noviembre de 2011): 4362–72. http://dx.doi.org/10.1091/mbc.e11-04-0283.

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Clustered protocadherins (Pcdhs) are arranged in gene clusters (α, β, and γ) with variable and constant exons. Variable exons encode cadherin and transmembrane domains and ∼90 cytoplasmic residues. The 14 Pcdh-αs and 22 Pcdh-γs are spliced to constant exons, which, for Pcdh-γs, encode ∼120 residues of an identical cytoplasmic moiety. Pcdh-γs participate in cell–cell interactions but are prominently intracellular in vivo, and mice with disrupted Pcdh-γ genes exhibit increased neuronal cell death, suggesting nonconventional roles. Most attention in terms of Pcdh-γ intracellular interactions has focused on the constant domain. We show that the variable cytoplasmic domain (VCD) is required for trafficking and organelle tubulation in the endolysosome system. Deletion of the constant cytoplasmic domain preserved the late endosomal/lysosomal trafficking and organelle tubulation observed for the intact molecule, whereas deletion or excision of the VCD or replacement of the Pcdh-γA3 cytoplasmic domain with that from Pcdh-α1 or N-cadherin dramatically altered trafficking. Truncations or internal deletions within the VCD defined a 26–amino acid segment required for trafficking and tubulation in the endolysosomal pathway. This active VCD segment contains residues that are conserved in Pcdh-γA and Pcdh-γB subfamilies. Thus the VCDs of Pcdh-γs mediate interactions critical for Pcdh-γ trafficking.

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29

Prapmasari, Dewi y M. Hudi Asrori S. "PELANGGARAN HAK CIPTA ATAS KARYA LAGU DAN MUSIK DALAM BENTUK PENJUALAN VCD ATAU DVD BAJAKAN DI YOGYAKARTA". Jurnal Hukum dan Pembangunan Ekonomi 7, n.º 2 (2 de agosto de 2019): 196. http://dx.doi.org/10.20961/hpe.v7i2.43004.

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Abstract This article aims to determine the perceptions of sellers and buyers about the sale of pirated VCD DVDs regulated in Law No. 28 of 2014 concerning Copyright and to know what factors can improve their legal protection.. The research methodology used is empirical research, namely secondary data published, for further research on primary data in the field or for the community. Legal research materials used are primary and secondary legal materials, techniques used in collecting legal materials are observation, interviews and study of documents or library materials. The results of the research show that the Copyright Law makes songs and music works as one of the protected creations, but there are still many people who do copyright by trading pirated DVDs or VCDs. The perception of the seller who is related to the Copyright Law concerning the need for the Act so as not to involve copyrighted parties, but there must also be a policy that no related party sells pirated VCDs or DVDs. In law enforcement the Copyright Act has several inhibiting factors, namely the legal factors themselves, law enforcement factors, facilities factors, community factors, cultural factors.Keywords: Offense; Copyright; Pirated VCD or DVD.Abstrak Artikel ini bertujuan untuk mengetahui persepsi para pelaku jualbeli mengenai penjualan DVD atau VCD bajakan yang diatur dalam Undang-Undang Nomor 28 Tahun 2014 tentang Hak Cipta dan mengetahui faktor-faktor apa saja yang menghambat perlindungan hukumnya. Metodologi penelitian yang digunakan adalah penelitian empiris, yaitu meneliti data sekunder pada awalnya, untuk kemudian dilanjutkan penelitian terhadap data primer di lapangan atau terhadap masyarakat. Bahan penelitian hukum yang digunakan adalah bahan hukum primer dan sekunder, teknik yang digunakan dalam pengumpulan bahan hukum adalah observasi, wawancara dan studi dokumen atau bahan pustaka. Hasil penelitian menunjukkan Undang- Undang Hak Cipta menjadikan karya lagu dan musik sebagai salah satu ciptaan yang dilindungi, namun masih banyak masyarakat yang melakukan pelanggaran hak cipta dengan memperjualbelikan DVD atau VCD bajakan. Persepsi para pelaku jualbeli terkait Undang-Undang Hak Cipta ialah pentingnya keberadaan UndangUndang tersebut agar tidak merugikan pihak pemegang hak cipta, namun perlu ada kebijakan agar tidak merugikan pihak pelaku jualbeli VCD atau DVD bajakan. Dalam penegakan hukum Undang-Undang Hak Cipta terdapat beberapa faktor yang penghambat yaitu faktor hukumnya sendiri, faktor penegak hukum, faktor sarana dan fasilitas, faktor masyarakat, faktor kebudayaan.Kata Kunci: Pelanggaran; Hak Cipta; VCD atau DVD Bajakan.

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Kim, Hyun Cheol, Pius Lee, Laura Judd, Li Pan y Barry Lefer. "OMI NO2 column densities over North American urban cities: the effect of satellite footprint resolution". Geoscientific Model Development 9, n.º 3 (22 de marzo de 2016): 1111–23. http://dx.doi.org/10.5194/gmd-9-1111-2016.

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Abstract. Nitrogen dioxide vertical column density (NO2 VCD) measurements via satellite are compared with a fine-scale regional chemistry transport model, using a new approach that considers varying satellite footprint sizes. Space-borne NO2 VCD measurement has been used as a proxy for surface nitrogen oxide (NOx) emission, especially for anthropogenic urban emission, so accurate comparison of satellite and modeled NO2 VCD is important in determining the future direction of NOx emission policy. The NASA Ozone Monitoring Instrument (OMI) NO2 VCD measurements, retrieved by the Royal Netherlands Meteorological Institute (KNMI), are compared with a 12 km Community Multi-scale Air Quality (CMAQ) simulation from the National Oceanic and Atmospheric Administration. We found that the OMI footprint-pixel sizes are too coarse to resolve urban NO2 plumes, resulting in a possible underestimation in the urban core and overestimation outside. In order to quantify this effect of resolution geometry, we have made two estimates. First, we constructed pseudo-OMI data using fine-scale outputs of the model simulation. Assuming the fine-scale model output is a true measurement, we then collected real OMI footprint coverages and performed conservative spatial regridding to generate a set of fake OMI pixels out of fine-scale model outputs. When compared to the original data, the pseudo-OMI data clearly showed smoothed signals over urban locations, resulting in roughly 20–30 % underestimation over major cities. Second, we further conducted conservative downscaling of OMI NO2 VCDs using spatial information from the fine-scale model to adjust the spatial distribution, and also applied averaging kernel (AK) information to adjust the vertical structure. Four-way comparisons were conducted between OMI with and without downscaling and CMAQ with and without AK information. Results show that OMI and CMAQ NO2 VCDs show the best agreement when both downscaling and AK methods are applied, with the correlation coefficient R = 0.89. This study suggests that satellite footprint sizes might have a considerable effect on the measurement of fine-scale urban NO2 plumes. The impact of satellite footprint resolution should be considered when using satellite observations in emission policy making, and the new downscaling approach can provide a reference uncertainty for the use of satellite NO2 measurements over most cities.

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Youn, Young Jin, Salman Khalid, Michael Azrin y Juyong Lee. "Stenosis Caused by Suture-Mediated Vascular Closure Device in an Angiographic Normal Common Femoral Artery: Its Mechanism and Management". Vascular and Endovascular Surgery 53, n.º 1 (9 de agosto de 2018): 58–61. http://dx.doi.org/10.1177/1538574418791883.

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Vascular closing devices (VCDs) are widely used to replace manual compression at the femoral puncture site and to reduce the discomfort of patients undergoing percutaneous coronary procedure by shortening bed rest. Among the vascular complications related to these devices, the femoral artery stenosis or occlusion is rarely reported, and its standard management is not well established. We report a case of symptomatic femoral artery stenosis caused by suture-mediated VCD and managed using rotational atherectomy device and balloon angioplasty. In addition, we propose the possible mechanisms for this complication.

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32

Irie, H., K. Yamaji, K. Ikeda, I. Uno, S. Itahashi, T. Ohara y J. Kurokawa. "An evaluation of the CMAQ reproducibility of satellite tropospheric NO2 column observations at different local times over East Asia". Atmospheric Chemistry and Physics Discussions 13, n.º 5 (28 de mayo de 2013): 14037–67. http://dx.doi.org/10.5194/acpd-13-14037-2013.

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Abstract. Despite the importance of the role of nitrogen dioxide (NO2) in tropospheric chemistry, the causes leading to the discrepancy between satellite-derived and modeled tropospheric NO2 vertical column densities (VCDs) over East Asia remain unclear. Here the reproducibility of satellite tropospheric NO2 VCD data by a regional chemical transport model (CMAQ) with the Regional Emission inventory in ASia (REAS) Version 2 is evaluated from the viewpoint of the diurnal variation of tropospheric NO2 VCDs, where satellite observations at different local times (SCIAMACHY/ENVISAT, OMI/Aura, and GOME-2/Metop-A) are utilized considering literature validation results. As a case study, we concentrate on June and December 2007 for a detailed evaluation based on various sensitivity simulations, for example with different spatial resolutions (80, 40, 20, and 10 km) for CMAQ. For June, CMAQ generally reproduces absolute values of satellite NO2 VCDs and their diurnal variations over all 12 selected diagnostic regions in East Asia. In contrast, a difficulty arises in interpreting the significant disagreement between satellite and CMAQ values over most of the diagnostic regions in December. The disagreement cannot be explained by any of the sensitivity simulations performed in this study. To address this, more investigations, including further efforts for satellite validations in wintertime, are needed.

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Compernolle, Steven, Tijl Verhoelst, Gaia Pinardi, José Granville, Daan Hubert, Arno Keppens, Sander Niemeijer et al. "Validation of Aura-OMI QA4ECV NO2 climate data records with ground-based DOAS networks: the role of measurement and comparison uncertainties". Atmospheric Chemistry and Physics 20, n.º 13 (10 de julio de 2020): 8017–45. http://dx.doi.org/10.5194/acp-20-8017-2020.

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Abstract. The QA4ECV (Quality Assurance for Essential Climate Variables) version 1.1 stratospheric and tropospheric NO2 vertical column density (VCD) climate data records (CDRs) from the OMI (Ozone Monitoring Instrument) satellite sensor are validated using NDACC (Network for the Detection of Atmospheric Composition Change) zenith-scattered light differential optical absorption spectroscopy (ZSL-DOAS) and multi-axis DOAS (MAX-DOAS) data as a reference. The QA4ECV OMI stratospheric VCDs have a small bias of ∼0.2 Pmolec.cm-2 (5 %–10 %) and a dispersion of 0.2 to 1 Pmolec.cm-2 with respect to the ZSL-DOAS measurements. QA4ECV tropospheric VCD observations from OMI are restricted to near-cloud-free scenes, leading to a negative sampling bias (with respect to the unrestricted scene ensemble) of a few peta molecules per square centimetre (Pmolec.cm-2) up to −10 Pmolec.cm-2 (−40 %) in one extreme high-pollution case. The QA4ECV OMI tropospheric VCD has a negative bias with respect to the MAX-DOAS data (−1 to −4 Pmolec.cm-2), which is a feature also found for the OMI OMNO2 standard data product. The tropospheric VCD discrepancies between satellite measurements and ground-based data greatly exceed the combined measurement uncertainties. Depending on the site, part of the discrepancy can be attributed to a combination of comparison errors (notably horizontal smoothing difference error), measurement/retrieval errors related to clouds and aerosols, and the difference in vertical smoothing and a priori profile assumptions.

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Grandhi, Ramesh, Xiaoran Zhang, David Panczykowski, Phillip Choi, Christopher T. Hunnicutt, Ashutosh P. Jadhav, Andrew F. Ducruet, Tudor Jovin y Brian Jankowitz. "Incidence of delayed angiographic femoral artery complications using the EXOSEAL vascular closure device". Interventional Neuroradiology 21, n.º 3 (26 de mayo de 2015): 401–6. http://dx.doi.org/10.1177/1591019915581776.

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Background and purpose Femoral artery injuries are known complications of percutaneous vascular closure devices (VCDs). We studied the incidence of delayed femoral artery angiographic irregularities after neurointerventional procedures in which the EXOSEAL extravascular closure device was used for femoral arterial puncture closure. Methods Adult patients who underwent femoral arterial puncture closures with an EXOSEAL VCD and had a follow-up femoral artery angiogram from June 2012 through August 2013 were reviewed. A blinded radiologist compared pre-deployment and follow-up femoral arteriograms for the presence of femoral artery stenosis, dissection, pseudoaneurysm, or development of an arteriovenous fistula. Hospital records were reviewed for major or minor complications of the groin site or femoral artery. Results The EXOSEAL VCD achieved hemostasis, without evidence of a groin hematoma or requiring subsequent prolonged manual compression, in 400 of 441 closures following transfemoral arterial access, representing a device success rate of 90.7%. A total of 98 patients underwent 102 repeat angiograms following closure with the EXOSEAL VCD. The average time to the repeat angiogram was 73.5 days (range 0–488, median 28). Follow-up femoral arteriography demonstrated an irregularity in seven cases, all of which were vessel stenoses of <50%. There were no dissections, pseudoaneurysms, infections, or ischemic events in the study population. Conclusions Angiographic irregularities were seen in 6.86% of cases after closure with the EXOSEAL VCD. There were no clinically significant vascular complications. Thus, femoral artery closure with EXOSEAL carries a low risk of clinically significant delayed angiographic findings.

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Shaiganfar, R., S. Beirle, M. Sharma, A. Chauhan, R. P. Singh y T. Wagner. "Estimation of NOx emissions from Delhi using car MAX-DOAS observations and comparison with OMI satellite data". Atmospheric Chemistry and Physics Discussions 11, n.º 7 (5 de julio de 2011): 19179–212. http://dx.doi.org/10.5194/acpd-11-19179-2011.

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Abstract. We present the first Multi-Axis- (MAX-) DOAS observations in India performed during April 2010 and January 2011 in Delhi and nearby regions. The MAX-DOAS instrument was mounted on a car roof, which allowed us to perform measurements along individual driving routes. From car MAX-DOAS observations along closed circles around Delhi, together with information on wind speed and direction, the NOx emissions from the greater Delhi area were determined: our estimate of 3.7 × 1025 molec s−1 is found to be slightly lower than the corresponding emission estimates using the EDGAR data base and substantially smaller compared to a recent study by Gurjar et al. (2004). We have also used the MAX-DOAS observations of the tropospheric NO2 VCD for validation of simultaneous satellite observations from the OMI instrument and found a good agreement of the spatial patterns. The absolute values show a reasonably good agreement. However, OMI data tends to underestimate the tropospheric NO2 VCDs in regions with high pollution levels, and tends to overestimate the tropospheric NO2 VCDs in more clean areas. These findings indicate possible discrepancies between the true vertical NO2 profiles and the profile assumptions in the OMI satellite retrieval.

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36

Tack, F., F. Hendrick, F. Goutail, C. Fayt, A. Merlaud, G. Pinardi, C. Hermans, J. P. Pommereau y M. Van Roozendael. "Tropospheric nitrogen dioxide column retrieval from ground-based zenith–sky DOAS observations". Atmospheric Measurement Techniques 8, n.º 6 (10 de junio de 2015): 2417–35. http://dx.doi.org/10.5194/amt-8-2417-2015.

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Abstract. We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith–sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the differential optical absorption spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS data set acquired with a multi-axis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from 10 June to 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In the case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different data sets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2-year data set, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).

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Tack, F., F. Hendrick, F. Goutail, C. Fayt, A. Merlaud, G. Pinardi, C. Hermans, J. P. Pommereau y M. Van Roozendael. "Tropospheric nitrogen dioxide column retrieval from ground-based zenith-sky DOAS observations". Atmospheric Measurement Techniques Discussions 8, n.º 1 (26 de enero de 2015): 935–85. http://dx.doi.org/10.5194/amtd-8-935-2015.

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Abstract. We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith-sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the Differential Optical Absorption Spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS dataset acquired with a Multi-AXis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from the 10 June to the 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different datasets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2 year dataset, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).

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Beirle, S., U. Platt, M. Wenig y T. Wagner. "Highly resolved global distribution of tropospheric NO2 using GOME narrow swath mode data". Atmospheric Chemistry and Physics Discussions 4, n.º 2 (16 de marzo de 2004): 1665–89. http://dx.doi.org/10.5194/acpd-4-1665-2004.

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Abstract. The Global Ozone Monitoring Experiment (GOME, since 1995) allows the retrieval of global total column densities of atmospheric trace gases, including NO2. Tropospheric vertical column densities (VCDs) are derived by estimating the stratospheric fraction from measurements over the remote ocean. Mean maps of tropospheric NO2 VCDs derived from GOME clearly allow to detect regions with enhanced industrial activity, but the standard spatial resolution of the GOME ground pixels (320×40 km2) is insufficient to resolve regional trace gas distributions or individual cities. Within the nominal GOME operation, every tenth day measurements in the so called narrow swath mode are executed with a much better spatial resolution (80×40 km2). Though the global coverage of these data is – due to the narrow swath – rather poor, the mean distribution over several years (1997–2001) allows to construct a much more detailed picture of the global NO2 distribution, especially if corrected for seasonal effects. It vividly illustrates the shortcomings of the standard size GOME pixels and reveals an unprecedented wealth of details in the global distribution of tropospheric NO2. Sharply localised spots of enhanced NO2 VCD can be associated directly to cities, large power plants, and heavy industry centers. The long time series of GOME data allows a quantitative comparison of the narrow swath mode data to the nominal resolution that holds general information on the dependency of NO2 VCDs on pixel size. This is important for new instruments like SCIAMACHY (launched March 2002 on ENVISAT) or OMI and GOME II (to be launched 2004 and 2005, respectively) with an improved spatial resolution.

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Slunsky, Pavel, Mathias Brunnberg, Shenja Lodersted y Leo Brunnberg. "Effect of intraoperative positioning on the diameter of the vertebral canal in cats during perineal urethrostomy (cadaveric study)". Journal of Feline Medicine and Surgery 20, n.º 1 (22 de mayo de 2017): 38–44. http://dx.doi.org/10.1177/1098612x17709645.

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Objectives The objective of this study was to quantify the changes in the diameter of the vertebral canal in the lumbosacral and sacrococcygeal column (L6–Co2) in cats in dorsal and ventral recumbency, simulating real body positioning during a perineal urethrostomy. Methods Twenty-one male feline cadavers were enrolled in the study. All feline cadavers were evaluated by CT. Examinations were performed with the cadaver in a neutral position and dorsal and ventral recumbency. Sagittal vertebral canal diameters (VCDs) were obtained by measuring the distance between the ventral and dorsal aspects of the vertebral canal in the middle of the intervertebral space. Results A comparison of the VCDs between L6 and L7, L7 and S1, S3 and Co1 and Co1 and Co2 in neutral position vs dorsal recumbency revealed a reduction of 0.27 mm (14.6%; P <0.001) between S3 and Co1 and 0.26 mm (18.1%; P <0.001) between Co1 and Co2. No differences were seen when comparing L6–L7 and L7–S1. The VCDs were decreased in all segments when comparing neutral with ventral recumbency. This study revealed a reduction of 0.13 mm between L6 and L7 (3.3%; P = 0.003), 0.14 mm between L7 and S1 (4.1%; P = 0.003), 0.61 mm between S3 and Co1 (32.5%; P <0.001) and 0.63 mm between Co1 and Co2 (44.1%; P <0.001). Comparison of the VCD between dorsal and ventral recumbency in L6–L7, L7–S1, S3–Co1 and Co1–Co2 revealed a decrease in the VCDs in ventral recumbency of 0.13 mm (3.3%; P <0.001), 0.12 mm (3.6%; P <0.001), 0.34 mm (21.0%; P <0.001) and 0.37 mm (31.7%; P <0.001), respectively. Conclusions and relevance The results provide evidence that, from an anatomical point of view, perineal urethrostomy performed in dorsal recumbency is superior to ventral recumbency, but further clinical studies to verify these findings are necessary.

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Wang, P., P. Stammes, R. van der A, G. Pinardi y M. van Roozendael. "FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric trace gas retrievals". Atmospheric Chemistry and Physics Discussions 8, n.º 3 (27 de mayo de 2008): 9697–729. http://dx.doi.org/10.5194/acpd-8-9697-2008.

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Abstract. The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. We compared FRESCO+ and FRESCO effective cloud fractions and cloud pressures using simulated spectra and one month of GOME measured spectra. As expected, FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar/lidar measurements of clouds shows that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. The effect of FRESCO+ cloud parameters on O3 and NO2 vertical column densities (VCD) is studied using SCIAMACHY data and ground-based DOAS measurements. We find that the FRESCO+ algorithm has a significant effect on tropospheric NO2 retrievals but a minor effect on total O3 retrievals. The retrieved SCIAMACHY tropospheric NO2 VCDs using FRESCO+ cloud parameters (v1.1) are lower than the tropospheric NO2 VCDs which used FRESCO cloud parameters (v1.04), in particular over heavily polluted areas with low clouds. The difference between SCIAMACHY tropospheric NO2 VCDs v1.1 and ground-based MAXDOAS measurements performed in Cabauw, The Netherlands, during the DANDELIONS campaign is about −2.12×1014 molec cm−2.

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Alattyih, Haider y Boussabaine. "Development of Value Creation Drivers for Sustainable Design of Green Buildings in Saudi Arabia". Sustainability 11, n.º 20 (22 de octubre de 2019): 5867. http://dx.doi.org/10.3390/su11205867.

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The sustainability of green buildings has been widely recognized around the world in the recent past. Evaluating the investment on such buildings, with higher complexity than the conventional buildings, involves multiple and diverse stakeholders, such as consultants, contractors, general public, governmental institutions, etc. The selection of useful value creation drivers is a difficult task while accommodating the opinion of a group of stakeholders with varying perceptions and experiences regarding the value creation in green building design and the associated costs. In this research, a framework is proposed to develop a set of the most important value creation drivers (VCDs) for green buildings. Five primary VCDs were developed to cover the financial, functional, operational, environmental, and management aspects of a green building. Ninety-eight (98) performance value drivers (PVDs) were identified through the literature for assessing the performance of these value creation drivers. The identified PVDs were evaluated through a hand-delivered questionnaire survey, followed by detailed statistical analysis of the collected data while using Statistical Package for Social Sciences (SPSS) and Microsoft Excel software. Factor analyses were performed to eliminate the PVDs with least importance based on the responses obtained from 89 experienced managers (45%), engineers (38%), and architects (17%) working in the field of value management of construction industry in Saudi Arabia. Finally, 51 most important PVDs were grouped into two clusters for each value creation driver; for instance, control and planning clusters to assess the performance of management’s VCD. The final outcome of the research in the form of five top level VCDs, 10 clusters, and 51 PVDs will facilitate the designers for enhancing the performance efficiency and value from investment for green buildings in Saudi Arabia, Gulf, and elsewhere.

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42

Kim, H. C., P. Lee, L. Judd, L. Pan y B. Lefer. "OMI NO2 column densities over North American urban cities: the effect of satellite footprint resolution". Geoscientific Model Development Discussions 8, n.º 10 (2 de octubre de 2015): 8451–79. http://dx.doi.org/10.5194/gmdd-8-8451-2015.

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Abstract. Nitrogen dioxide vertical column density (NO2 VCD) measurements via satellite are compared with a fine-scale regional chemistry transport model, using a new approach that considers varying satellite footprint sizes. Space-borne NO2 VCD measurement has been used as a proxy for surface nitrogen oxide (NOx) emission, especially for anthropogenic urban emission, so accurate comparison of satellite and modeled NO2 VCD is important in determining the future direction of NOx emission policy. The National Aeronautics and Space Administration Ozone Monitoring Instrument (OMI) NO2 VCD measurements, retrieved by the Royal Netherlands Meteorological Institute (KNMI), are compared with a 12 km Community Multi-scale Air Quality (CMAQ) simulation from the National Oceanic and Atmospheric Administration. We found that OMI footprint pixel sizes are too coarse to resolve urban NO2 plumes, resulting in a possible underestimation in the urban core and overestimation outside. In order to quantify this effect of resolution geometry, we have made two estimates. First, we constructed pseudo-OMI data using fine-scale outputs of the model simulation. Assuming the fine-scale model output is a true measurement, we then collected real OMI footprint coverages and performed conservative spatial regridding to generate a set of fake OMI pixels out of fine-scale model outputs. When compared to the original data, the pseudo-OMI data clearly showed smoothed signals over urban locations, resulting in roughly 20–30 % underestimation over major cities. Second, we further conducted conservative downscaling of OMI NO2 VCD using spatial information from the fine-scale model to adjust the spatial distribution, and also applied Averaging Kernel (AK) information to adjust the vertical structure. Four-way comparisons were conducted between OMI with and without downscaling and CMAQ with and without AK information. Results show that OMI and CMAQ NO2 VCDs show the best agreement when both downscaling and AK methods are applied, with correlation coefficient R = 0.89. This study suggests that satellite footprint sizes might have a considerable effect on the measurement of fine-scale urban NO2 plumes. The impact of satellite footprint resolution should be considered when using satellite observations in emission policy making, and the new downscaling approach can provide a reference uncertainty for the use of satellite NO2 measurements over most cities.

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Tack, Frederik, Alexis Merlaud, Andreas C. Meier, Tim Vlemmix, Thomas Ruhtz, Marian-Daniel Iordache, Xinrui Ge et al. "Intercomparison of four airborne imaging DOAS systems for tropospheric NO2 mapping – the AROMAPEX campaign". Atmospheric Measurement Techniques 12, n.º 1 (11 de enero de 2019): 211–36. http://dx.doi.org/10.5194/amt-12-211-2019.

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Abstract. We present an intercomparison study of four airborne imaging DOAS instruments, dedicated to the retrieval and high-resolution mapping of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs). The AROMAPEX campaign took place in Berlin, Germany, in April 2016 with the primary objective to test and intercompare the performance of experimental airborne imagers. The imaging DOAS instruments were operated simultaneously from two manned aircraft, performing synchronised flights: APEX (VITO–BIRA-IASB) was operated from DLR's DO-228 D-CFFU aircraft at 6.2 km in altitude, while AirMAP (IUP-Bremen), SWING (BIRA-IASB), and SBI (TNO–TU Delft–KNMI) were operated from the FUB Cessna 207T D-EAFU at 3.1 km. Two synchronised flights took place on 21 April 2016. NO2 slant columns were retrieved by applying differential optical absorption spectroscopy (DOAS) in the visible wavelength region and converted to VCDs by the computation of appropriate air mass factors (AMFs). Finally, the NO2 VCDs were georeferenced and mapped at high spatial resolution. For the sake of harmonising the different data sets, efforts were made to agree on a common set of parameter settings, AMF look-up table, and gridding algorithm. The NO2 horizontal distribution, observed by the different DOAS imagers, shows very similar spatial patterns. The NO2 field is dominated by two large plumes related to industrial compounds, crossing the city from west to east. The major highways A100 and A113 are also identified as line sources of NO2. Retrieved NO2 VCDs range between 1×1015 molec cm−2 upwind of the city and 20×1015 molec cm−2 in the dominant plume, with a mean of 7.3±1.8×1015 molec cm−2 for the morning flight and between 1 and 23×1015 molec cm−2 with a mean of 6.0±1.4×1015 molec cm−2 for the afternoon flight. The mean NO2 VCD retrieval errors are in the range of 22 % to 36 % for all sensors. The four data sets are in good agreement with Pearson correlation coefficients better than 0.9, while the linear regression analyses show slopes close to unity and generally small intercepts.

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Rahayu, Satutik, Nur Lestari y I. Gde Mertha. "Development Teaching Basic Skill’s VCD Media to Improve Teaching Skills in Subjects Micro Teaching". Jurnal Pendidikan Fisika dan Teknologi 4, n.º 2 (22 de noviembre de 2018): 247. http://dx.doi.org/10.29303/jpft.v4i2.837.

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This study aims to: 1) determine the quality of the results of VCDs that have been developed, 2) find out whether there is an increase in student teaching skills in micro-learning. This research is a development research using ADDIE (Analysis, Design, Development, Implementation and Evaluation) models. Validation of learning videos is done by learning media experts and user response questionnaires. Data analysis used descriptive analysis and N-Gain test. The results showed that the average score of the media expert validation was 86.7% in the good and usable category, while the results of the user response questionnaire were 87.9% in the good category and suitable for use. Hail the N-gain test found that there was an increase in the basic teaching skills of students after using the VCD of basic teaching skills in the micro-learning course which was 0.7.

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Kille, Natalie, Sunil Baidar, Philip Handley, Ivan Ortega, Roman Sinreich, Owen R. Cooper, Frank Hase, James W. Hannigan, Gabriele Pfister y Rainer Volkamer. "The CU mobile Solar Occultation Flux instrument: structure functions and emission rates of NH3, NO2 and C2H6". Atmospheric Measurement Techniques 10, n.º 1 (1 de febrero de 2017): 373–92. http://dx.doi.org/10.5194/amt-10-373-2017.

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Abstract. We describe the University of Colorado mobile Solar Occultation Flux instrument (CU mobile SOF). The instrument consists of a digital mobile solar tracker that is coupled to a Fourier transform spectrometer (FTS) of 0.5 cm−1 resolution and a UV–visible spectrometer (UV–vis) of 0.55 nm resolution. The instrument is used to simultaneously measure the absorption of ammonia (NH3), ethane (C2H6) and nitrogen dioxide (NO2) along the direct solar beam from a moving laboratory. These direct-sun observations provide high photon flux and enable measurements of vertical column densities (VCDs) with geometric air mass factors, high temporal resolution of 2 s and spatial resolution of 5–19 m. It is shown that the instrument line shape (ILS) of the FTS is independent of the azimuth and elevation angle pointing of the solar tracker. Further, collocated measurements next to a high-resolution FTS at the National Center for Atmospheric Research (HR-NCAR-FTS) show that the CU mobile SOF measurements of NH3 and C2H6 are precise and accurate; the VCD error at high signal to noise ratio is 2–7 %. During the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) from 21 July to 3 September 2014 in Colorado, the CU mobile SOF instrument measured median (minimum, maximum) VCDs of 4.3 (0.5, 45) × 1016 molecules cm−2 NH3, 0.30 (0.06, 2.23) × 1016 molecules cm−2 NO2 and 3.5 (1.5, 7.7) × 1016 molecules cm−2 C2H6. All gases were detected in larger 95 % of the spectra recorded in urban, semi-polluted rural and remote rural areas of the Colorado Front Range. We calculate structure functions based on VCDs, which describe the variability of a gas column over distance, and find the largest variability for NH3. The structure functions suggest that currently available satellites resolve about 10 % of the observed NH3 and NO2 VCD variability in the study area. We further quantify the trace gas emission fluxes of NH3 and C2H6 and production rates of NO2 from concentrated animal feeding operations (CAFO) using the mass balance method, i.e., the closed-loop vector integral of the VCD times wind speed along the drive track. Excellent reproducibility is found for NH3 fluxes and also, to a lesser extent, NO2 production rates on 2 consecutive days; for C2H6 the fluxes are affected by variable upwind conditions. Average emission factors were 12.0 and 11.4 gNH3 h−1 head−1 at 30 °C for feedlots with a combined capacity for ∼ 54 000 cattle and a dairy farm of ∼ 7400 cattle; the pooled rate of 11.8 ± 2.0 gNH3 h−1 head−1 is compatible with the upper range of literature values. At this emission rate the NH3 source from cattle in Weld County, CO (535 766 cattle), could be underestimated by a factor of 2–10. CAFO soils are found to be a significant source of NOx. The NOx source accounts for ∼ 1.2 % of the N flux in NH3 and has the potential to add ∼ 10 % to the overall NOx emissions in Weld County and double the NOx source in remote areas. This potential of CAFO to influence ambient NOx concentrations on the regional scale is relevant because O3 formation is NOx sensitive in the Colorado Front Range. Emissions of NH3 and NOx are relevant for the photochemical O3 and secondary aerosol formation.

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de Leeuw, Johannes, Anja Schmidt, Claire S. Witham, Nicolas Theys, Isabelle A. Taylor, Roy G. Grainger, Richard J. Pope, Jim Haywood, Martin Osborne y Nina I. Kristiansen. "The 2019 Raikoke volcanic eruption – Part 1: Dispersion model simulations and satellite retrievals of volcanic sulfur dioxide". Atmospheric Chemistry and Physics 21, n.º 14 (19 de julio de 2021): 10851–79. http://dx.doi.org/10.5194/acp-21-10851-2021.

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Abstract. Volcanic eruptions can cause significant disruption to society, and numerical models are crucial for forecasting the dispersion of erupted material. Here we assess the skill and limitations of the Met Office's Numerical Atmospheric-dispersion Modelling Environment (NAME) in simulating the dispersion of the sulfur dioxide (SO2) cloud from the 21–22 June 2019 eruption of the Raikoke volcano (48.3∘ N, 153.2∘ E). The eruption emitted around 1.5±0.2 Tg of SO2, which represents the largest volcanic emission of SO2 into the stratosphere since the 2011 Nabro eruption. We simulate the temporal evolution of the volcanic SO2 cloud across the Northern Hemisphere (NH) and compare our model simulations to high-resolution SO2 measurements from the TROPOspheric Monitoring Instrument (TROPOMI) and the Infrared Atmospheric Sounding Interferometer (IASI) satellite SO2 products. We show that NAME accurately simulates the observed location and horizontal extent of the SO2 cloud during the first 2–3 weeks after the eruption but is unable, in its standard configuration, to capture the extent and precise location of the highest magnitude vertical column density (VCD) regions within the observed volcanic cloud. Using the structure–amplitude–location (SAL) score and the fractional skill score (FSS) as metrics for model skill, NAME shows skill in simulating the horizontal extent of the cloud for 12–17 d after the eruption where VCDs of SO2 (in Dobson units, DU) are above 1 DU. For SO2 VCDs above 20 DU, which are predominantly observed as small-scale features within the SO2 cloud, the model shows skill on the order of 2–4 d only. The lower skill for these high-SO2-VCD regions is partly explained by the model-simulated SO2 cloud in NAME being too diffuse compared to TROPOMI retrievals. Reducing the standard horizontal diffusion parameters used in NAME by a factor of 4 results in a slightly increased model skill during the first 5 d of the simulation, but on longer timescales the simulated SO2 cloud remains too diffuse when compared to TROPOMI measurements. The skill of NAME to simulate high SO2 VCDs and the temporal evolution of the NH-mean SO2 mass burden is dominated by the fraction of SO2 mass emitted into the lower stratosphere, which is uncertain for the 2019 Raikoke eruption. When emitting 0.9–1.1 Tg of SO2 into the lower stratosphere (11–18 km) and 0.4–0.7 Tg into the upper troposphere (8–11 km), the NAME simulations show a similar peak in SO2 mass burden to that derived from TROPOMI (1.4–1.6 Tg of SO2) with an average SO2 e-folding time of 14–15 d in the NH. Our work illustrates how the synergy between high-resolution satellite retrievals and dispersion models can identify potential limitations of dispersion models like NAME, which will ultimately help to improve dispersion modelling efforts of volcanic SO2 clouds.

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Butz, André, Anna Solvejg Dinger, Nicole Bobrowski, Julian Kostinek, Lukas Fieber, Constanze Fischerkeller, Giovanni Bruno Giuffrida et al. "Remote sensing of volcanic CO2, HF, HCl, SO2, and BrO in the downwind plume of Mt. Etna". Atmospheric Measurement Techniques 10, n.º 1 (2 de enero de 2017): 1–14. http://dx.doi.org/10.5194/amt-10-1-2017.

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Abstract. Remote sensing of the gaseous composition of non-eruptive, passively degassing volcanic plumes can be a tool to gain insight into volcano interior processes. Here, we report on a field study in September 2015 that demonstrates the feasibility of remotely measuring the volcanic enhancements of carbon dioxide (CO2), hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO2), and bromine monoxide (BrO) in the downwind plume of Mt. Etna using portable and rugged spectroscopic instrumentation. To this end, we operated the Fourier transform spectrometer EM27/SUN for the shortwave-infrared (SWIR) spectral range together with a co-mounted UV spectrometer on a mobile platform in direct-sun view at 5 to 10 km distance from the summit craters. The 3 days reported here cover several plume traverses and a sunrise measurement. For all days, intra-plume HF, HCl, SO2, and BrO vertical column densities (VCDs) were reliably measured exceeding 5 × 1016, 2 × 1017, 5 × 1017, and 1 × 1014 molec cm−2, with an estimated precision of 2.2 × 1015, 1.3 × 1016, 3.6 × 1016, and 1.3 × 1013 molec cm−2, respectively. Given that CO2, unlike the other measured gases, has a large and well-mixed atmospheric background, derivation of volcanic CO2 VCD enhancements (ΔCO2) required compensating for changes in altitude of the observing platform and for background concentration variability. The first challenge was met by simultaneously measuring the overhead oxygen (O2) columns and assuming covariation of O2 and CO2 with altitude. The atmospheric CO2 background was found by identifying background soundings via the co-emitted volcanic gases. The inferred ΔCO2 occasionally exceeded 2 × 1019 molec cm−2 with an estimated precision of 3.7 × 1018 molec cm−2 given typical atmospheric background VCDs of 7 to 8 × 1021 molec cm−2. While the correlations of ΔCO2 with the other measured volcanic gases confirm the detection of volcanic CO2 enhancements, correlations were found of variable significance (R2 ranging between 0.88 and 0.00). The intra-plume VCD ratios ΔCO2 ∕ SO2, SO2 ∕ HF, SO2 ∕ HCl, and SO2 ∕ BrO were in the range 7.1 to 35.4, 5.02 to 21.2, 1.54 to 3.43, and 2.9 × 103 to 12.5 × 103, respectively, showing pronounced day-to-day and intra-day variability.

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Merlaud, Alexis, Livio Belegante, Daniel-Eduard Constantin, Mirjam Den Hoed, Andreas Carlos Meier, Marc Allaart, Magdalena Ardelean et al. "Satellite validation strategy assessments based on the AROMAT campaigns". Atmospheric Measurement Techniques 13, n.º 10 (15 de octubre de 2020): 5513–35. http://dx.doi.org/10.5194/amt-13-5513-2020.

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Abstract. The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaigns took place in Romania in September 2014 and August 2015. They focused on two sites: the Bucharest urban area and large power plants in the Jiu Valley. The main objectives of the campaigns were to test recently developed airborne observation systems dedicated to air quality studies and to verify their applicability for the validation of space-borne atmospheric missions such as the TROPOspheric Monitoring Instrument (TROPOMI)/Sentinel-5 Precursor (S5P). We present the AROMAT campaigns from the perspective of findings related to the validation of tropospheric NO2, SO2, and H2CO. We also quantify the emissions of NOx and SO2 at both measurement sites. We show that tropospheric NO2 vertical column density (VCD) measurements using airborne mapping instruments are well suited for satellite validation in principle. The signal-to-noise ratio of the airborne NO2 measurements is an order of magnitude higher than its space-borne counterpart when the airborne measurements are averaged at the TROPOMI pixel scale. However, we show that the temporal variation of the NO2 VCDs during a flight might be a significant source of comparison error. Considering the random error of the TROPOMI tropospheric NO2 VCD (σ), the dynamic range of the NO2 VCDs field extends from detection limit up to 37 σ (2.6×1016 molec. cm−2) and 29 σ (2×1016 molec. cm−2) for Bucharest and the Jiu Valley, respectively. For both areas, we simulate validation exercises applied to the TROPOMI tropospheric NO2 product. These simulations indicate that a comparison error budget closely matching the TROPOMI optimal target accuracy of 25 % can be obtained by adding NO2 and aerosol profile information to the airborne mapping observations, which constrains the investigated accuracy to within 28 %. In addition to NO2, our study also addresses the measurements of SO2 emissions from power plants in the Jiu Valley and an urban hotspot of H2CO in the centre of Bucharest. For these two species, we conclude that the best validation strategy would consist of deploying ground-based measurement systems at well-identified locations.

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Chan, Ka Lok, Zhuoru Wang, Aijun Ding, Klaus-Peter Heue, Yicheng Shen, Jing Wang, Feng Zhang, Yining Shi, Nan Hao y Mark Wenig. "MAX-DOAS measurements of tropospheric NO2 and HCHO in Nanjing and a comparison to ozone monitoring instrument observations". Atmospheric Chemistry and Physics 19, n.º 15 (9 de agosto de 2019): 10051–71. http://dx.doi.org/10.5194/acp-19-10051-2019.

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Abstract. In this paper, we present long-term observations of atmospheric nitrogen dioxide (NO2) and formaldehyde (HCHO) in Nanjing using a Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument. Ground-based MAX-DOAS measurements were performed from April 2013 to February 2017. The MAX-DOAS measurements of NO2 and HCHO vertical column densities (VCDs) are used to validate ozone monitoring instrument (OMI) satellite observations over Nanjing. The comparison shows that the OMI observations of NO2 correlate well with the MAX-DOAS data with Pearson correlation coefficient (R) of 0.91. However, OMI observations are on average a factor of 3 lower than the MAX-DOAS measurements. Replacing the a priori NO2 profiles by the MAX-DOAS profiles in the OMI NO2 VCD retrieval would increase the OMI NO2 VCDs by ∼30 % with correlation nearly unchanged. The comparison result of MAX-DOAS and OMI observations of HCHO VCD shows a good agreement with R of 0.75 and the slope of the regression line is 0.99. An age-weighted backward-propagation approach is applied to the MAX-DOAS measurements of NO2 and HCHO to reconstruct the spatial distribution of NO2 and HCHO over the Yangtze River Delta during summer and winter time. The reconstructed NO2 fields show a distinct agreement with OMI satellite observations. However, due to the short atmospheric lifetime of HCHO, the backward-propagated HCHO data do not show a strong spatial correlation with the OMI HCHO observations. The result shows that the MAX-DOAS measurements are sensitive to the air pollution transportation in the Yangtze River Delta, indicating the air quality in Nanjing is significantly influenced by regional transportation of air pollutants. The MAX-DOAS data are also used to evaluate the effectiveness of air pollution control measures implemented during the Youth Olympic Games 2014. The MAX-DOAS data show a significant reduction of ambient aerosol, NO2 and HCHO (30 %–50 %) during the Youth Olympic Games. Our results provide a better understanding of the transportation and sources of pollutants over the Yangtze River Delta as well as the effect of emission control measures during large international events, which are important for the future design of air pollution control policies.

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Ye, Sheng, Shengxin Liu, Wenlei Li, Qifan Wang, Wei Xi y Xin Zhang. "Associations between anthropometric indicators and both refraction and ocular biometrics in a cross-sectional study of Chinese schoolchildren". BMJ Open 9, n.º 5 (mayo de 2019): e027212. http://dx.doi.org/10.1136/bmjopen-2018-027212.

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ObjectiveTo identify associations between anthropometric indicators (height, weight and body mass index (BMI)) and both refraction and ocular biometrics in Chinese schoolchildren in Tianjin, China.DesignCross-sectional study.ParticipantsA total of 482 (86.07%) students (6–15 years old) with no history of ocular or systemic pathologies were enrolled in this study.MethodologyHeight and weight were measured using standardised protocols. Ocular biometrics (axial length (AL), vitreous chamber depth (VCD) and corneal curvature (CC)) were measured by a low-coherence optical reflectometry device. Cycloplegic refraction was measured using autorefraction. The AL/CC ratio and spherical equivalent refraction (SER) were calculated. Myopia was defined as SER ≤−0.50 dioptres (D). Multiple linear regression analysis was performed to explore the associations between anthropometric indicators (height, weight and BMI) and both refraction and ocular biometrics.ResultsThe overall prevalence of myopia was 71.16%. Overall, only height was associated with ALs, VCDs, AL/CC ratios and refractions after controlling for age, gender, parental myopia, family income, reading and writing distance and time spent outdoors. Furthermore, age-specific results demonstrated that height and weight were independently associated with refraction in participants aged 6–8 years and 9–11 years participants. Higher heights in schoolchildren were associated with longer ALs (regression coefficientb=+0.25 for each 10 cm difference in height, p<0.01), deeper VCDs (b=+0.23, p<0.01), higher AL/CC ratios (b=+0.04, p<0.01) and more negative refractions (b=−0.48, p<0.01). Heavier weights were also associated with longer ALs (+0.29 mm, p<0.01), deeper VCDs (+0.29 mm, p<0.01), higher AL/CC ratios (+0.04, p<0.01) and more negative refractions (−0.48 D, p<0.01).ConclusionsHeight and weight remained independently related to refraction and various ocular biometrics during the early adolescent growth period after adequately controlling for covariates, which could support the idea that a shared mechanism may regulate the coordinated growth of body and eye size in children.

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