Artículos de revistas: "Pole Discovery"

1

Brown, M. E., A. L. Smith, C. Chen y M. Ádámkovics. "DISCOVERY OF FOG AT THE SOUTH POLE OF TITAN". Astrophysical Journal 706, n.º 1 (2 de noviembre de 2009): L110—L113. http://dx.doi.org/10.1088/0004-637x/706/1/l110.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Robinson, Michael. "Manliness and Exploration: The Discovery of the North Pole". Osiris 30, n.º 1 (enero de 2015): 89–109. http://dx.doi.org/10.1086/682968.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Osczevski, Randall J. "Frederick Cook's polar journey: a reconstruction". Polar Record 26, n.º 158 (julio de 1990): 225–32. http://dx.doi.org/10.1017/s0032247400011475.

Texto completo

Resumen

AbstractThe data used by Dr Frederick A. Cook in support of his claim to have reached the North Pole on 21 April 1908 are reinterpreted to support a hypothesis that Cook did not reach the Pole, that his journey towards the Pole lasted only one week, and thathe subsequently discovered and visited Meighen Island. This reconstruction explains how Dr Cook could have made observations of ice conditions and drift, and of an ice island, without having travelled far out on the Arctic Ocean. A possible reason for his failure to announce discovery of Meighen Island is also offered.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Fiennes, Ranulph y Wally Herbert. "The Noose of Laurels: The Discovery of the North Pole". Geographical Journal 156, n.º 2 (julio de 1990): 231. http://dx.doi.org/10.2307/635363.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Peacock, T., M. Cropper, J. Bailey, J. H. Hough y D. T. Wickramasinghe. "Polarimetry of ST LMi: discovery of a second accreting pole". Monthly Notices of the Royal Astronomical Society 259, n.º 3 (1 de diciembre de 1992): 583–92. http://dx.doi.org/10.1093/mnras/259.3.583.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Caldwell, Douglas A., William J. Borucki, Robert L. Showen, Jon M. Jenkins, Laurance Doyle, Zoran Ninkov y Michael Ashley. "Detecting Extrasolar Planet Transits from the South Pole". Symposium - International Astronomical Union 213 (2004): 93–96. http://dx.doi.org/10.1017/s0074180900193052.

Texto completo

Resumen

We have developed and tested a wide-field photometer to detect extrasolar planet transits from the South Pole. The discovery of transiting planets for which masses can be measured by radial velocity is vital to constrain the models of planet formation and evolution. Short of going to space, the South Pole is the best site from which to carry out a such a survey. Based on results from the Doppler velocity surveys and the Vulcan transit search, we expect to detect 10 to 15 transiting planets in two years of operation at the South Pole.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Benson, Bradford. "The South Pole Telescope: Latest Results and Future Prospects". Proceedings of the International Astronomical Union 8, S288 (agosto de 2012): 76–79. http://dx.doi.org/10.1017/s1743921312016705.

Texto completo

Resumen

AbstractThe South Pole Telescope is a 10 meter telescope optimized for sensitive, high-resolution measurements of the cosmic microwave background (CMB) anisotropy and millimeter-wavelength sky. In November 2011, the SPT completed the 2500 deg2 SPT-SZ survey. The survey has led to several major cosmological results, derived from measurements of the fine angular scale primary and secondary CMB anisotropies, the discovery of galaxy clusters via the Sunyaev-Zel'dovich (SZ) effect and the resulting mass-limited cluster catalog, and the discovery of a population of distant, dusty star forming galaxies (DSFGs). In January 2012, the SPT was equipped with a new polarization sensitive camera, SPTpol, which will enable detection of the contribution to the CMB polarization power spectrum from lensing by large scale structure (the so-called “lensing B-modes”) and, on larger angular scales, a detection or improved upper limit on the primordial inflationary signal (“gravitational-wave B-modes”), thereby constraining the energy scale of Inflation. Development is underway for SPT-3G, the third-generation camera for SPT. The SPT-3G survey will cross the threshold from statistical detection of B-mode CMB lensing to imaging the fluctuations at high signal-to-noise; enabling the separation of lensing and inflationary B-modes and improving the constraint on the sum of the neutrino masses Σmν to a level relevant for exploring the neutrino mass hierarchy.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Landi, Sofia M., Pooja Viswanathan, Stephen Serene y Winrich A. Freiwald. "A fast link between face perception and memory in the temporal pole". Science 373, n.º 6554 (1 de julio de 2021): 581–85. http://dx.doi.org/10.1126/science.abi6671.

Texto completo

Resumen

The question of how the brain recognizes the faces of familiar individuals has been important throughout the history of neuroscience. Cells linking visual processing to person memory have been proposed but not found. Here, we report the discovery of such cells through recordings from an area in the macaque temporal pole identified with functional magnetic resonance imaging. These cells responded to faces that were personally familiar. They responded nonlinearly to stepwise changes in face visibility and detail and holistically to face parts, reflecting key signatures of familiar face recognition. They discriminated between familiar identities, as fast as a general face identity area. The discovery of these cells establishes a new pathway for the fast recognition of familiar individuals.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Williams, Isobel. "Dr Edward Wilson (1872-1912): Antarctic Hero". Journal of Medical Biography 17, n.º 2 (28 de abril de 2009): 111–15. http://dx.doi.org/10.1258/jmb.2009.009009.

Texto completo

Resumen

Edward Wilson was an artist, doctor, naturalist and explorer. He was on both Scott's Antarctic expeditions of the early 1900s, as Junior Surgeon and Zoologist on the Discovery expedition of 1901 and as Chief of Scientific Staff on the Terra Nova expedition of 1910. He reached the Pole with Scott in 1912 and died with him on their ill-fated return from the Pole.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Jing, Chun Guo y Jun Wei Wang. "Simulation of Street Light Pole Controller Routing with OMNeT++". Applied Mechanics and Materials 401-403 (septiembre de 2013): 1976–80. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.1976.

Texto completo

Resumen

In street lighting system, the light pole controllers were used to monitoring and control each street light. The controller nodes were installed at each lighting pole and make up a network with RTUs. In this paper, a randomly forwarding routing strategy was proposed based on the controller network features. The controller nodes were divided many clusters according to the substation power scope. In one cluster, the controller nodes topology is mainly star structure. When a controller node received a packet, it randomly delays a period of time and decides forwarding packet instead of immediately forwarding. The decision is based on the packet propagation direction and other nodes whether sending or not. The randomly forwarding routing protocol were simulated in OMNeT++ environment and compared with the flooding protocol. The results show that the delay of proposed protocol is lower than that of flooding. The proposed protocol also has some special features such as simple, not need to maintain net topology and complex path discovery algorithms.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Mohandas, Namitha, Neil D. Young, Abdul Jabbar, Pasi K. Korhonen, Anson V. Koehler, Parisa Amani, Ross S. Hall et al. "The barber's pole worm CAP protein superfamily — A basis for fundamental discovery and biotechnology advances". Biotechnology Advances 33, n.º 8 (diciembre de 2015): 1744–54. http://dx.doi.org/10.1016/j.biotechadv.2015.07.003.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Mittaz, J. P. D., S. R. Rosen, K. O. Mason y S. B. Howell. "Discovery of a new pole-occulting AM Her star using the ROSAT Wide-Field Camera". Monthly Notices of the Royal Astronomical Society 258, n.º 2 (15 de septiembre de 1992): 277–84. http://dx.doi.org/10.1093/mnras/258.2.277.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Henry, J. P., I. M. Gioia, C. R. Mullis, D. I. Clowe, G. A. Luppino, H. Boehringer, U. G. Briel, W. Voges y J. P. Huchra. "Discovery of a Redshift 0.8 Cluster of Galaxies in the ROSAT North Ecliptic Pole Survey." Astronomical Journal 114 (octubre de 1997): 1293. http://dx.doi.org/10.1086/118562.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Tammiksaar, E. "The Russian Antarctic Expedition under the command of Fabian Gottlieb von Bellingshausen and its reception in Russia and the world". Polar Record 52, n.º 5 (11 de julio de 2016): 578–600. http://dx.doi.org/10.1017/s0032247416000449.

Texto completo

Resumen

ABSTRACTThe existence of an icy continent around the South Pole is known to everybody today. But it is common to ascribe this kind of modern knowledge to navigators sailing in southern polar waters in the 19th century. A good illustration of this is the Russian Antarctic expedition (1819–1821) under the conduct of Fabian Gottlieb von Bellingshausen (Russian version Faddej Faddeevich Bellinsgauzen), the reception of which in Russian society of the 19th and 20th centuries is analysed in this article. During the cold war, beginning at the end of the 1940s, the question of who discovered Antarctica turned from being a scientific problem into a subject of political struggle between the United States of America, Great Britain and the Soviet Union. This article provides an analysis of the Russian discovery in the area, while at the same time, attempting to give an answer to the main question of the history of Antarctic exploration which is: is it well-justified to establish the first discoverer of Antarctica? All the dates in the text are according to the Gregorian calendar.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Splettstoesser, John. "Antarctican Society centennial medallion". Polar Record 50, n.º 2 (6 de mayo de 2011): 219. http://dx.doi.org/10.1017/s0032247411000192.

Texto completo

Resumen

The Antarctican Society, based in the United States, has produced a medallion (Fig. 1) in recognition of the centennial of the discovery of the South Pole by Roald Amundsen and Captain Robert Falcon Scott, in 1911 and 1912, respectively. This item is representative of both expeditions.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Lagrange, A. M., M. Keppler, H. Beust, L. Rodet, N. Meunier, J. Lillo-Box, M. Bonnefoy y F. Galland. "Discovery of a stellar companion to HD 131399A". Astronomy & Astrophysics 608 (diciembre de 2017): L9. http://dx.doi.org/10.1051/0004-6361/201730978.

Texto completo

Resumen

Context. The giant exoplanets imaged on wide orbits (≥10 au) around young stars challenge the classical theories of planet formation. The presence of perturbing bodies could have played a role in the dynamical evolution of the planets once formed. Aims. We aim to search for close companions to HD 131399, a star around which a giant planet has been discovered, at a projected separation of about 80 au. The star also appears to be a member of a wide (320 au) binary system. Methods. We recorded HARPS high resolution spectra in January 2017. Results. We find that HD 131399A is probably seen close to pole-on. We discover a low mass star companion that orbits with a period of about 10 days on a misaligned orbit. Even though the companion does not have an impact on the current dynamical evolution of the planet, it could have played a role in its setting and in clearing the circumstellar disk from which the planet may originate.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Cooke, Graeme, Hugues A. de Cremiers, Florence M. A. Duclairoir, Julie Leonardi, Georgina Rosair y Vincent M. Rotello. "Ferrocene incorporating host–guest dyads with electrochemically controlled three-pole hydrogen bonding properties". Tetrahedron 59, n.º 18 (abril de 2003): 3341–47. http://dx.doi.org/10.1016/s0040-4020(03)00423-x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Kim, Kidong, Suhyun Hwangbo, Taesung Park, Hyojin Kim, Yong Beom Kim, Jae Hong No, Dong-Hoon Suh y Ju-Hyun Kim. "Clinicopathologic and protein markers distinguishing POLE and copy-number low group in endometrial cancer." Journal of Clinical Oncology 38, n.º 15_suppl (20 de mayo de 2020): e18110-e18110. http://dx.doi.org/10.1200/jco.2020.38.15_suppl.e18110.

Texto completo

Resumen

e18110 Background: Requirement of DNA sequencing to diagnose POLE group is a barrier for adoption of molecular subtyping in endometrial cancer. We aimed to identify clinicopathologic and protein markers distinguishing POLE and copy-number (CN) low group in endometrial cancer. Methods: Ninety-one samples (POLE: 15, CN low 76) classified as POLE or CN low groups by integrative clustering were selected from The Cancer Genome Atlas endometrial cancer dataset. Clinicopathologic variables and normalized reverse phase protein array expression data were extracted. We first selected clinicopathologic variables associated with group (POLE vs CN low) via univariate analysis. Then, we identified protein makers using the logistic regression model with significant clinicopathologic variables as adjusting covariates. The differentially expressed proteins were selected based on q-value of the false discovery rate for multiple comparison. With various q-value cut-off ( < 5%, 10%, 20%), several logistic models including differentially expressed markers were constructed by stepwise selection method using the area under curve (AUC) from 5-fold cross-validation (CV). Results: Among clinicopathologic variables, body mass index (BMI) and tumor grade were associated with group (p = 0.02 and p < 0.01, respectively). Being adjusted for BMI and tumor grade, 5 proteins were associated with group in q-value cut-off of < 5%. The model including clinicopathologic variables and 5 proteins identified BMI, Cyclin B1, Caspase 8, and XBP1 as markers distinguishing POLE and CN low groups. The mean of CV AUC, sensitivity and specificity of the selected model were 0.97, 0.97, and 0.60, respectively. Conclusions: BMI and expression levels of Cyclin B1, Caspase 8, XBP1 are candidate markers distinguishing POLE and CN low group. A further validation study using immunohistochemical staining is necessary to facilitate the adoption of molecular subtyping as daily practice.

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Szoke, Tamar, Nitsan Albocher, Sutharsan Govindarajan, Anat Nussbaum-Shochat y Orna Amster-Choder. "Tyrosine phosphorylation-dependent localization of TmaR that controls activity of a major bacterial sugar regulator by polar sequestration". Proceedings of the National Academy of Sciences 118, n.º 2 (29 de diciembre de 2020): e2016017118. http://dx.doi.org/10.1073/pnas.2016017118.

Texto completo

Resumen

The poles of Escherichia coli cells are emerging as hubs for major sensory systems, but the polar determinants that allocate their components to the pole are largely unknown. Here, we describe the discovery of a previously unannotated protein, TmaR, which localizes to the E. coli cell pole when phosphorylated on a tyrosine residue. TmaR is shown here to control the subcellular localization and activity of the general PTS protein Enzyme I (EI) by binding and polar sequestration of EI, thus regulating sugar uptake and metabolism. Depletion or overexpression of TmaR results in EI release from the pole or enhanced recruitment to the pole, which leads to increasing or decreasing the rate of sugar consumption, respectively. Notably, phosphorylation of TmaR is required to release EI and enable its activity. Like TmaR, the ability of EI to be recruited to the pole depends on phosphorylation of one of its tyrosines. In addition to hyperactivity in sugar consumption, the absence of TmaR also leads to detrimental effects on the ability of cells to survive in mild acidic conditions. Our results suggest that this survival defect, which is sugar- and EI-dependent, reflects the difficulty of cells lacking TmaR to enter stationary phase. Our study identifies TmaR as the first, to our knowledge, E. coli protein reported to localize in a tyrosine-dependent manner and to control the activity of other proteins by their polar sequestration and release.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Hentschel, Klaus. "An unwelcome discovery: The pole effect in the electric arc, a threat to early 20th century precision spectrometry". Archive for History of Exact Sciences 51, n.º 3 (1997): 199–271. http://dx.doi.org/10.1007/bf00384117.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Hromakina, T. A., I. N. Belskaya, Yu N. Krugly, V. G. Shevchenko, J. L. Ortiz, P. Santos-Sanz, R. Duffard et al. "Long-term photometric monitoring of the dwarf planet (136472) Makemake". Astronomy & Astrophysics 625 (mayo de 2019): A46. http://dx.doi.org/10.1051/0004-6361/201935274.

Texto completo

Resumen

Aims. We studied the rotational properties of the dwarf planet Makemake. Methods. The photometric observations were carried out at different telescopes between 2006 and 2017. Most of the measurements were acquired in BVRI broad-band filters of a standard Johnson-Cousins photometric system. Results. We found that Makemake rotates more slowly than was previously reported. A possible lightcurve asymmetry suggests a double-peaked period of P = 22.8266 ± 0.0001 h. A small peak-to-peak lightcurve amplitude in R-filter A = 0.032 ± 0.005 mag implies an almost spherical shape or near pole-on orientation. We also measured BVRI colours and the R-filter phase-angle slope and revised the absolute magnitudes. The absolute magnitude of Makemake has remained unchanged since its discovery in 2005. No direct evidence of a newly discovered satellite was found in our photometric data; however, we discuss the possible existence of another larger satellite.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Forsberg, Magnus. "Chapter 3. The place names of Franz Josef Land: framing the problem". Septentrio Conference Series, n.º 3 (9 de septiembre de 2015): 17. http://dx.doi.org/10.7557/5.3580.

Texto completo

Resumen

A brief introduction to the geographic place names of Franz Josef Land. Franz Josef Land is located in the western Arctic though for much of the 20th Century it was closed behind the Iron Curtain. Prior to that, there were a series of Western expeditions between the ‘official’ discovery in 1873 and the departure of the American Fiala group in 1905. From these expeditions, the islands are heavily connected to the history of the search for the North Pole.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Majidi, Vahid y David M. Coleman. "Magnetic Confinement and Control of Trajectories of Discharge Species in Atmospheric-Pressure Analytical Spark Discharges". Applied Spectroscopy 41, n.º 2 (febrero de 1987): 200–207. http://dx.doi.org/10.1366/000370287774986859.

Texto completo

Resumen

A series of experiments, designed to help characterize the behavior of an analytical spark discharge in an external pulsed magnetic field, is described. Results include controlled formation and deformation of a spark's post-discharge torus utilizing different magnetic field configurations. One manifestation of this research was discovery of a new filamentary structure which extends from the spark conducting channel to the magnet pole face(s). These features were investigated via their refracted light (Schlieren) and spectroscopic (time/space/wavelength-resolved) properties. Practical ramifications of this control are discussed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Rowe, Sophie. "On the provenance of a historic sledge shoe fragment, said to have been collected by Edward Wilson at the South Pole in 1912". Polar Record 53, n.º 4 (julio de 2017): 413–26. http://dx.doi.org/10.1017/s0032247417000365.

Texto completo

Resumen

ABSTRACTThis paper discusses the authentication of a metal sledge shoe fragment, believed by the owner to have been collected by Edward Wilson close to the South Pole on 18 January 1912. Microscopic and elemental analysis show that the object is made from ‘German silver’, a copper alloy used only on Norwegian Nansen-style sledges in the late nineteenth and early twentieth century, and that it was used to clad a tapering sledge runner end about 10 mm thick. By comparing related objects, including sledges used by Amundsen and Scott in their South Pole journeys and a sledge from the Discovery Expedition, we show that the object cannot have come from an English sledge, but would have fitted one of Amundsen's modified sledges. Written sources have been extensively searched, but no direct written provenance for the object exists. However, contemporary Norwegian and British accounts explain specific features of the object and exclude other possible provenances. We conclude that it is most likely that the proposed provenance and history attached to this artefact are correct.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Yusofi, Mahdy, Saeid Zarghami-Hamrah, Yahya Ghaedy y Alireza Mahmudnia. "A quasi-transcendental approach for removing hierarchical teacher-student relation". Policy Futures in Education 16, n.º 3 (3 de noviembre de 2017): 346–59. http://dx.doi.org/10.1177/1478210317736205.

Texto completo

Resumen

In the present study, we adopt a quasi-transcendental approach in order to deconstruct the teacher–student relationship. According to the results of this study, teacher is the dominant pole and student is the passive one. This relation should be redefined in order to transfer students to the dominant pole. In this improvement process the authoritative role of teachers as information transferors and developers is changed to helpers and facilitators. The results of quasi-transcendental analysis of the teacher–student relationship indicated that the conceptual emergence of being a teacher and being a student are dependent and make sense together. Therefore, a teacher is essential for defining student status and vice versa. In this way, they are defined together and in the absence of one of them, the other one would be meaningless. As a result, students would assume a more active role in the educational process and they would deal with the discovery and construction of knowledge in an action-based process. Furthermore, the student would realize concepts such as the centrality of learner, cooperative learning, etc., more efficiently.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Bernat, Paolo. "Sfida all’ultimo parallelo: la conquista del Polo Sud cento anni dopo". ACME - Annali della Facoltà di Lettere e Filosofia dell’Università degli Studi di Milano, n.º 03 (diciembre de 2012): 17–28. http://dx.doi.org/10.7358/acme-2012-003-bern.

Texto completo

Resumen

100 years ago, Antarctica was still mostly unknown and unexplored. The first landings on the Antarctic coast took place in the early decades of the nineteenth century and were made by whalers and sealers. In the following years the first scientific expeditions began and European and US expeditions started the geographical discovery and the mapping of the Antarctic coasts. But it was only in the years 1911-1912 that two expeditions, very different but equally well prepared, arrived almost simultaneously at the South Pole. The events that happened in the Antarctic together with the different nature of the two leaders Roald Amundsen and Robert Scott determined the outcome of these expeditions and the fate of their teams. The centenary of the conquest of the South Pole (December 14, 1911) is an opportunity to remember the passion for science, the spirit of adventure and the fierce perseverance that characterized those extraordinary men and that even now form the basis of scientific research and of human progress, not only in Antarctica but in all areas of knowledge and life.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Raja, Ramij, Majidul Rahaman, Abhirup Datta, Reinout J. van Weeren, Huib T. Intema y Surajit Paul. "A low-frequency radio halo survey of the South Pole Telescope SZ-selected clusters with the GMRT". Monthly Notices of the Royal Astronomical Society 500, n.º 2 (5 de noviembre de 2020): 2236–49. http://dx.doi.org/10.1093/mnras/staa3432.

Texto completo

Resumen

ABSTRACT The presence of non-thermal electrons and large-scale magnetic fields in the intracluster medium is known through the detection of megaparsec (Mpc) scale diffuse radio synchrotron emission. Although a significant amount of progress in finding new diffuse radio sources has happened in the last decade, most of the investigation has been constrained towards massive low-redshift clusters. In this work, we explore clusters with redshift z > 0.3 in search of diffuse radio emission, at 325 MHz with the Giant Metrewave Radio Telescope. This campaign has resulted in the discovery of two new radio haloes (SPT-CL J0013−4906 and SPT-CL J0304−4401) along with two other detections (SPT-CL J2031−4037 and SPT-CL J2248−4431), previously reported (at 325 MHz) in the literature. In addition, we detect a halo candidate in one cluster in our sample, and upper limits for haloes are placed in eight clusters where no diffuse emission is detected. In the P1.4–LX plane, the detected haloes follow the observed correlation, whereas the upper limits lie above the correlation line, indicating the possibility of future detection with sensitive observations.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Le, Thuy G., Abhijit Kundu, Atanu Ghoshal, Nghi H. Nguyen, Sarah Preston, Yaqing Jiao, Banfeng Ruan et al. "Optimization of Novel 1-Methyl-1H-Pyrazole-5-carboxamides Leads to High Potency Larval Development Inhibitors of the Barber’s Pole Worm". Journal of Medicinal Chemistry 61, n.º 23 (7 de noviembre de 2018): 10875–94. http://dx.doi.org/10.1021/acs.jmedchem.8b01544.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

VENTO, VICENTE. "HIDDEN DIRAC MONOPOLES". International Journal of Modern Physics A 23, n.º 24 (30 de septiembre de 2008): 4023–37. http://dx.doi.org/10.1142/s0217751x08041669.

Texto completo

Resumen

Dirac showed that the existence of one magnetic pole in the universe could offer an explanation of the discrete nature of the electric charge. Magnetic poles appear naturally in most grand unified theories. Their discovery would be of greatest importance for particle physics and cosmology. The intense experimental search carried thus far has not met with success. I propose a universe with magnetic poles which are not observed free because they hide in deeply bound monopole–antimonopole states named monopolium. I discuss the realization of this proposal and its consistency with known cosmological features. I furthermore analyze its implications and the experimental signatures that confirm the scenario.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Ivanišević, Milan. "First look into the eye". European Journal of Ophthalmology 29, n.º 6 (7 de octubre de 2018): 685–88. http://dx.doi.org/10.1177/1120672118804388.

Texto completo

Resumen

Purpose: Until Helmholtz’s discovery of the ophthalmoscope, it was not possible to visualize the posterior pole of the eye in a living subject. The aim of this work is to emphasize the importance of the invention of the ophthalmoscope because the new era in ophthalmology began with it. Methods: Available literature concerning this topic was studied, especially by getting in contact with institutes for history of medicine as well as medico-historians in Germany and other countries. Results: Hermann von Helmholtz, German physician and physicist, presented and published his invention of the ophthalmoscope in 1851. Albrecht von Graefe was the first to use ophthalmoscope routinely. He said: ‘Helmholtz has opened a new world to us’. The first ophthalmoscope was not easy to use. Some ophthalmologists even thought that ophthalmoscopy is harmful for the eye, particularly for a diseased eye. First, it was used in Germany (A von Graefe), Austria (E Jäger), and Netherlands (FC Donders). In England, it was used only at Moorfields till 1855 (W Bowman). At the First International Congress of Ophthalmology in Brussels 1857, the importance of ophthalmoscopy was stressed. FC Donders said that every view with the ophthalmoscope into the living eye was a new discovery. Among retinal diseases, first were discovered pigment retinopathy (FC Donders) and retinal detachment (A Coccius) in 1853. Conclusion: Helmholtz inaugurated modern era in ophthalmology with his magnificant instrument which revolutionized the development of ophthalmology. Von Graefe popularized it. Because of the new findings, ophthalmology was definitely separated from surgery in the middle of 19th century.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Clowes, Roger G., Angela Iovino y Peter Shaver. "Clustering of Quasars from the ROE/ESO Large-Scale AQD Survey for Quasars". Symposium - International Astronomical Union 124 (1987): 809–14. http://dx.doi.org/10.1017/s0074180900159959.

Texto completo

Resumen

The new ROE/ESO large-scale AQD survey for quasars forms a connected area of ∼ 200 deg2 near the south galactic pole, and has resulted in the discovery of a total number of quasar candidates that is comparable to the number previously published from all other sources (see the poster paper by Iovino, Clowes & Shaver at this conference). In this paper we describe the first results of a three-dimensional self-clustering analysis of ∼ 1100 “high-probability” candidates occupying the assigned-redshift band of 1.8 to 2.4. Although the analysis is sensitive to very weak clustering we find no evidence that quasars are distributed in any way other than randomly. The implications of this result are discussed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Melchior, P. "Theories of Polar Motion from Tisserand to Poincaré (1890 – 1910)". International Astronomical Union Colloquium 178 (2000): 41–66. http://dx.doi.org/10.1017/s0252921100061194.

Texto completo

Resumen

AbstractThe discovery by Seth C. Chandler (1891) that the motion of the pole (the reality of which had been established by K.F. Küstner and by the simultaneous latitude observations at Honolulu and Berlin by German astronomers) resulted from two components i.e. a free circular motion with a period of 427 days and a forced elliptical motion with a period of 365.25 days, raised considerable interest in the scientific community of astronomers and geophysicists.The celebrated Mécanique Céleste of Tisserand (1890) had been published just one year before at a time when doubts still persisted and arguments could be presented in favor of the fixed pole. Starting with Tisserand’s arguments, we describe in this paper the impact of the successive contributions by A. Greenhill, S. Newcomb, Th. Sloudsky, S. Hough, G. Herglotz, A. Love, J. Larmor and H. Poincaré to the solution of the problems raised by the Chandler period.The lines of reasoning taken by these eminent scientists were rigorously correct so that, after about one hundred years, contemporary researchers, who benefit from a far better knowledge of the inner structure of the Earth and are able to take advantage of modern computing power, do not contradict any of their conclusions and instead refine them with an accuracy which was not imaginable one century ago.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Giannaccare, Giuseppe, Marco Pellegrini, Carlotta Senni, Federico Bernabei, Vincenzo Scorcia y Arrigo Francesco Giuseppe Cicero. "Clinical Applications of Astaxanthin in the Treatment of Ocular Diseases: Emerging Insights". Marine Drugs 18, n.º 5 (1 de mayo de 2020): 239. http://dx.doi.org/10.3390/md18050239.

Texto completo

Resumen

Astaxanthin is a naturally occurring red carotenoid pigment belonging to the family of xanthophylls, and is typically found in marine environments, especially in microalgae and seafood such as salmonids, shrimps and lobsters. Due to its unique molecular structure, astaxanthin features some important biologic properties, mostly represented by strong antioxidant, anti-inflammatory and antiapoptotic activities. A growing body of evidence suggests that astaxanthin is efficacious in the prevention and treatment of several ocular diseases, ranging from the anterior to the posterior pole of the eye. Therefore, the present review aimed at providing a comprehensive evaluation of current clinical applications of astaxanthin in the management of ocular diseases. The efficacy of this carotenoid in the setting of retinal diseases, ocular surface disorders, uveitis, cataract and asthenopia is reported in numerous animal and human studies, which highlight its ability of modulating several metabolic pathways, subsequently restoring the cellular homeostatic balance. To maximize its multitarget therapeutic effects, further long-term clinical trials are warranted in order to define appropriate dosage, route of administration and exact composition of the final product.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Shelswell, Kristopher J., Terumi A. Taylor y J. Thomas Beatty. "Photoresponsive Flagellum-Independent Motility of the Purple Phototrophic Bacterium Rhodobacter capsulatus". Journal of Bacteriology 187, n.º 14 (julio de 2005): 5040–43. http://dx.doi.org/10.1128/jb.187.14.5040-5043.2005.

Texto completo

Resumen

ABSTRACT We report the discovery of photoresponsive, flagellum-independent motility of the α-proteobacterium Rhodobacter capsulatus, a nonsulfur purple phototrophic bacterium. This motility takes place in the 1.5% agar-glass interface of petri plates but not in soft agar, and cells move toward a light source. The appearances of motility assay plates inoculated with wild-type or flagellum-deficient mutants indicate differential contributions from flagellar and flagellum-independent mechanisms. Electron microscopy confirmed the absence of flagella in flagellar mutants and revealed the presence of pilus-like structures at one pole of wild-type and mutant cells. We suggest that R. capsulatus utilizes a flagellum-independent, photoresponsive mechanism that resembles twitching motility to move in a line away from the point of inoculation toward a light source.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Halsey, Lewis G. y Mike A. Stroud. "100 Years Since Scott Reached the Pole: A Century of Learning About the Physiological Demands of Antarctica". Physiological Reviews 92, n.º 2 (abril de 2012): 521–36. http://dx.doi.org/10.1152/physrev.00031.2011.

Texto completo

Resumen

The 1910–1913 Terra Nova Expedition to the Antarctic, led by Captain Robert Falcon Scott, was a venture of science and discovery. It is also a well-known story of heroism and tragedy since his quest to reach the South Pole and conduct research en route, while successful was also fateful. Although Scott and his four companions hauled their sledges to the Pole, they died on their return journey either directly or indirectly from the extreme physiological stresses they experienced. One hundred years on, our understanding of such stresses caused by Antarctic extremes and how the body reacts to severe exercise, malnutrition, hypothermia, high altitude, and sleep deprivation has greatly advanced. On the centenary of Scott's expedition to the bottom of the Earth, there is still controversy surrounding whether the deaths of those five men could have, or should have, been avoided. This paper reviews present-day knowledge related to the physiology of sustained man-hauling in Antarctica and contrasts this with the comparative ignorance about these issues around the turn of the 20th century. It closes by considering whether, with modern understanding about the effects of such a scenario on the human condition, Scott could have prepared and managed his team differently and so survived the epic 1,600-mile journey. The conclusion is that by carrying rations with a different composition of macromolecules, enabling greater calorific intake at similar overall weight, Scott might have secured the lives of some of the party, and it is also possible that enhanced levels of vitamin C in his rations, albeit difficult to achieve in 1911, could have significantly improved their survival chances. Nevertheless, even with today's knowledge, a repeat attempt at his expedition would by no means be bound to succeed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Yang, Pin y Maolin Guo. "Interaction of Some Non-Platinum Metal Anticancer Complexes With Nucleotides and DNA and The Two-Pole Complementary Principle (TPCP) Arising Therefrom". Metal-Based Drugs 5, n.º 1 (1 de enero de 1998): 41–58. http://dx.doi.org/10.1155/mbd.1998.41.

Texto completo

Resumen

The binding modes of some non-platinum metal anticancer complexes, Cp2TiCl2, Cp2ZrCl2, (CH3)2SnCl2, (C2H5)2SnCl2, (C2H5)2SnCl2(phen) (phen=Phenanthroline) and cis-RuIICl2(DMSO)3 (DMSO) (cis-RDT) with nucleotides and DNA in aqueous solution at physiological pH values were investigated by various modern techniques. 5'-dGMP with Cp2TiCl2 or cis-RDT forms chelate complexes in which both N7 and phosphate of dGMP bind to the metal center. Whereas Cp2ZrCl2 and all the diorganotin compounds can bind dGMP only via the phosphate group. The investigations of the interactions between Cp2TiCl2 or (C2H5)2SnCl2 and DNA indicate that there are two types of binding sites on DNA for Cp2TiCl2, i.e., the base nitrogen rings and the phosphate group, while (C2H5)2SnCl2 can bind to DNA only via the phosphate group. At last, by carefully comparing and analysing the binding modes-activity relationships of the above anticancer complexes and other non-platinum and platinum anticancer complexes, a hypothesis named “Two-Pole Complementary Principle” was put forward.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Dean, Ryan, Ganesh Maniam y Thien Vo. "A rare case of renal cell carcinoma with hematogenous extension into the right atrium discovered incidentally on echocardiogram". Southwest Respiratory and Critical Care Chronicles 8, n.º 34 (25 de abril de 2020): 52–55. http://dx.doi.org/10.12746/swrccc.v8i34.655.

Texto completo

Resumen

While hematogenous spread of renal cell carcinoma (RCC) is common, isolated extension into the renal vein and inferior vena cava (IVC) is rare and extension to the right atrium is even less likely. In the case, a 62-year-old Hispanic female was admitted for a suspected inferior myocardial infarction, and her echocardiogram revealed a right atrial mass consistent with the appearance of an atrial myxoma. Following cardiac catheterization, a histopathological examination of the mass revealed a clear cell tumor consistent with metastatic clear cell RCC. Following a CABG with excision of the atrial mas, the CT demonstrated a 5 cm right lower pole renal mass with hilar involvement, as well as filling defects in the IVC extending into the right renal vein; these findings were consistent with RCC tumor thrombus extension into the renal vein, IVC, and right atrium. The radical nephrectomy necessary for tumor removal could not be performed at this hospital, so the patient was discharged to a higher level of care. The incidence rate for RCC with extension into the right atrium is quite low, but clinicians should understand the lethality of RCC warrants immediate clinical investigation upon diagnosis. The increased utilization of sophisticated imaging modalities will likely continue to increase the rate of incidental discovery of such neoplasms, and physicians should keep RCC on the differential when a right atrial mass is discovered incidentally on echocardiogram.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Chen, Yin-Ju, Guo-Rung You, Meng-Yu Lai, Long-Sheng Lu, Chang-Yu Chen, Lai-Lei Ting, Hsin-Lun Lee, Yuzuka Kanno, Jeng-Fong Chiou y Ann-Joy Cheng. "A Combined Systemic Strategy for Overcoming Cisplatin Resistance in Head and Neck Cancer: From Target Identification to Drug Discovery". Cancers 12, n.º 11 (23 de noviembre de 2020): 3482. http://dx.doi.org/10.3390/cancers12113482.

Texto completo

Resumen

Cisplatin is the first-line chemotherapy agent for head and neck cancer (HNC), but its therapeutic effects are hampered by its resistance. In this study, we employed systemic strategies to overcome cisplatin resistance (CR) in HNC. CR cells derived from isogenic HNC cell lines were generated. The CR related hub genes, functional mechanisms, and the sensitizing candidates were globally investigated by transcriptomic and bioinformatic analyses. Clinically, the prognostic significance was assessed by the Kaplan–Meier method. Cellular and molecular techniques, including cell viability assay, tumorsphere formation assay, RT-qPCR, and immunoblot, were used. Results showed that these CR cells possessed highly invasive and stem-like properties. A total of 647 molecules was identified, and the mitotic division exhibited a novel functional mechanism significantly related to CR. A panel of signature molecules, MSRB3, RHEB, ULBP1, and spindle pole body component 25 (SPC25), was found to correlate with poor prognosis in HNC patients. SPC25 was further shown as a prominent molecule, which markedly suppressed cancer stemness and attenuated CR after silencing. Celastrol, a nature extract compound, was demonstrated to effectively inhibit SPC25 expression and reverse CR phenotype. In conclusion, the development of SPC25 inhibitors, such as the application of celastrol, maybe a novel strategy to sensitize cisplatin for the treatment of refractory HNC.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Carter, Christopher. ""The sea fryseth not": science and the open polar sea in the nineteenth century". Earth Sciences History 32, n.º 2 (1 de enero de 2013): 235–351. http://dx.doi.org/10.17704/eshi.32.2.p4808m837636388x.

Texto completo

Resumen

While generally dismissed by historians as a romantic fantasy, the theory of an open polar sea fit into the context of a more unified view of the natural world developed in the early nineteenth century and exemplified by romantic philosophical ideas. Oersted's discovery of electromagnetism encouraged research into the possible connections between electricity, magnetism, heat and light. At the same time, there was renewed interest in geomagnetism inspired by Hansteen's revival of the four-pole theory of the Earth's magnetic field. Incorporating these works into a new theory of climate created a space for an ice-free Arctic by allowing a milder climate in the high latitudes. This attempt to fuse the study of meteorology and geomagnetism reinforced existing beliefs in an open polar sea and placed this sailor's dream into a holistic worldview that joined different natural phenomena in an effort to find one unifying principle behind all of nature.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Mercier, Romain, Sarah Bautista, Maëlle Delannoy, Margaux Gibert, Annick Guiseppi, Julien Herrou, Emilia M. F. Mauriello y Tâm Mignot. "The polar Ras-like GTPase MglA activates type IV pilus via SgmX to enable twitching motility inMyxococcus xanthus". Proceedings of the National Academy of Sciences 117, n.º 45 (22 de octubre de 2020): 28366–73. http://dx.doi.org/10.1073/pnas.2002783117.

Texto completo

Resumen

Type IV pili (Tfp) are highly conserved macromolecular structures that fulfill diverse cellular functions, such as adhesion to host cells, the import of extracellular DNA, kin recognition, and cell motility (twitching). Outstandingly, twitching motility enables a poorly understood process by which highly coordinated groups of hundreds of cells move in cooperative manner, providing a basis for multicellular behaviors, such as biofilm formation. In the social bacteriaMyxococcus xanthus, we know that twitching motility is under the dependence of the small GTPase MglA, but the underlying molecular mechanisms remain elusive. Here we show that MglA complexed to GTP recruits a newly characterized Tfp regulator, termed SgmX, to activate Tfp machines at the bacterial cell pole. This mechanism also ensures spatial regulation of Tfp, explaining how MglA switching provokes directional reversals. This discovery paves the way to elucidate how polar Tfp machines are regulated to coordinate multicellular movements, a conserved feature in twitching bacteria.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Stolarski, Richard S., Richard D. McPeters y Paul A. Newman. "The Ozone Hole of 2002 as Measured by TOMS". Journal of the Atmospheric Sciences 62, n.º 3 (1 de marzo de 2005): 716–20. http://dx.doi.org/10.1175/jas-3338.1.

Texto completo

Resumen

Abstract Since its discovery in 1985, the ozone hole has been regularly mapped using the data from Total Ozone Mapping Spectrometer (TOMS) instruments on several satellites. The current TOMS, on the Earth Probe satellite, has been taking measurements since 1996. The ozone hole first appeared during the 1980s. Since 1990, the hole has consistently developed during each Antarctic spring over a broad area with the minimum total ozone value reaching about 100 Dobson units (DU; 1 DU = 2.69 × 1016 molecules cm−2) in late September or early October. The year 2002 was markedly different from the past 12 years. A series of strong wave events weakened the South Polar vortex. In late September, a major stratospheric warming took place, reversing the direction of the polar flow and the latitudinal temperature gradient. This warming resulted in a division of the ozone hole into two pieces, one that migrated to lower latitudes and disappeared and one that reformed over the Pole in a weakened form. The development of this year’s unusual ozone hole is shown here and is contrasted to a climatology of the years since 1990. Minimum daily values of total ozone barely reached 150 DU in contrast to values nearer to 100. The area of the ozone hole briefly reached 18 × 106 km2, then dropped rapidly to only 2 × 106 km2, and finally recovered to about 8 × 106 km2 before disappearing in early November. The positive anomaly compared with the last 12 yr near the Pole was accompanied by a smaller negative anomaly north of 45°S.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Shepherd, Russell. "America's First Commercial Oil Well Shepherd". Earth Sciences History 7, n.º 2 (1 de enero de 1988): 134–39. http://dx.doi.org/10.17704/eshi.7.2.62071v5226328835.

Texto completo

Resumen

The first commercial oil well in North America was drilled with a spring pole rig in 1818 by Marcus Huling on the South Fork of the Cumberland River in McCreary County, Kentucky. The well was 200 feet deep and flowed at the surface. The discovery was reported in the fall of 1818 in the newspaper Argus of Western America, and in a letter written by Huling in 1820. Oil from the well was sold locally and also in Tennessee, North Carolina, and Georgia. Two thousand gallons were exported to Europe. Comparison of early geologic and structure sections and maps with recent publications and field data indicates that, in contrast to previous interpretations, the accumulation, in the Big Lime, is stratigraphically controlled. Today oil can be sampled from a well at the site, now in a National River Recreation Area. Employing formal definitions, the Beatty well may become generally recognized as the first-documented comercial oil well in North America, even though it was originally drilled for salt.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Jones, William C. "Precision CMB Measurements from Long Duration Stratospheric Balloons: Towards B-modes and Inflation". Proceedings of the International Astronomical Union 8, S288 (agosto de 2012): 53–60. http://dx.doi.org/10.1017/s1743921312016675.

Texto completo

Resumen

AbstractObservations of the Cosmic Microwave Background (CMB) have played a leading role in establishing an understanding of the structure and evolution of the Universe on the largest scales. This achievement has been enabled by a series of extremely successful experiments, coupled with the simplicity of the relationship between the cosmological theory and data. Antarctic experiments, including both balloon-borne telescopes and instruments at the South Pole, have played a key role in realizing the scientific potential of the CMB, from the characterization of the temperature anisotropies to the detection and study of the polarized component. Current and planned Antarctic long duration balloon experiments will extend this heritage of discovery to test theories of cosmic genesis through sensitive polarized surveys of the millimeter-wavelength sky. In this paper we will review the pivotal role that Antarctic balloon borne experiments have played in transforming our understanding of the Universe, and describe the scientific goals and technical approach of current and future missions.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Cheng, Chen y Xiao-Yun Wang. "The Production of Neutral N∗(11052) Resonance with Hidden Beauty from π-p Scattering". Advances in High Energy Physics 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/9398732.

Texto completo

Resumen

We investigate the discovery potential of the predicted neutral hidden beauty N∗(11052) resonance through π-p scattering within an effective Lagrangian approach. Two reactions π-p→K-Σ+ and π-p→ηbn are studied in this work, with nucleon pole exchange as the background. It is found that the contributions of the N∗(11052) resonance give clear peak structures in the magnitude of 1 μb near the threshold of N∗(11052) in the total cross sections. The numerical results indicate that the center of mass energy W≃11–11.1 GeV would be the best energy window for searching the N∗(11052) resonance, where the N∗(11052) signal can be easily distinguished from the background. The COMPASS experiment at CERN’s Super Proton Synchrotron (SPS) with pion beam of ≃280 GeV will be an ideal platform for searching the super-heavy resonance with hidden beauty, which is promising for testing the theoretical results.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Meagher, Kevin J. "Neutrino Astronomy with IceCube". Proceedings of the International Astronomical Union 12, S324 (septiembre de 2016): 322–29. http://dx.doi.org/10.1017/s1743921317002307.

Texto completo

Resumen

AbstractThe IceCube Neutrino Observatory is a cubic kilometer neutrino telescope located at the Geographic South Pole. Cherenkov radiation emitted by charged secondary particles from neutrino interactions is observed by IceCube using an array of 5160 photomultiplier tubes embedded between a depth of 1.5 km to 2.5 km in the Antarctic glacial ice. The detection of astrophysical neutrinos is a primary goal of IceCube and has now been realized with the discovery of a diffuse, high-energy flux consisting of neutrino events from tens of TeV up to several PeV. Many analyses have been performed to identify the source of these neutrinos: correlations with active galactic nuclei, gamma-ray bursts, and the galactic plane. IceCube also conducts multi-messenger campaigns to alert other observatories of possible neutrino transients in real-time. However, the source of these neutrinos remains elusive as no corresponding electromagnetic counterparts have been identified. This proceeding will give an overview of the detection principles of IceCube, the properties of the observed astrophysical neutrinos, the search for corresponding sources (including real-time searches), and plans for a next-generation neutrino detector, IceCube–Gen2.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Henrichs, Huib F., Katrien Kolenberg, Benjamin Plaggenborg, Stephen C. Marsden, Ian A. Waite y Gregg A. Wade. "The magnetic field of the B1/B2V star σ Lup". Proceedings of the International Astronomical Union 6, S272 (julio de 2010): 192–93. http://dx.doi.org/10.1017/s1743921311010295.

Texto completo

Resumen

AbstractThe ultraviolet stellar wind lines of the photometrically periodic variable early B-type star σ Lupi were found to behave very similarly to what has been observed in known magnetic B stars, although no periodicity could be determined. AAT spectropolarimetric measurements with SEMPOL were obtained. We detected a longitudinal magnetic field with varying strength and amplitude of about 100 G with error bars of typically 20 G. This type of variability supports an oblique magnetic rotator model. We fold the equivalent width of the 4 usable UV spectra in phase with the well-known photometric period of 3.019 days, which we identify with the rotation period of the star. The magnetic field variations are consistent with this period. Additional observations with ESPaDOnS attached to the CFHT strongly confirmed this discovery, and allowed to determine a precise magnetic period. Like in the other magnetic B stars the wind emission likely originates in the magnetic equatorial plane, with maximum emission occurring when a magnetic pole points towards the Earth. The 3.0182 d magnetic rotation period is consistent with the photometric period, with maximum light corresponding to maximum magnetic field. No helium or other chemical peculiarity is known for this object.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Kipping, David, David Nesvorný, Joel Hartman, Guillermo Torres, Gaspar Bakos, Tiffany Jansen y Alex Teachey. "A resonant pair of warm giant planets revealed by TESS". Monthly Notices of the Royal Astronomical Society 486, n.º 4 (11 de mayo de 2019): 4980–86. http://dx.doi.org/10.1093/mnras/stz1141.

Texto completo

Resumen

ABSTRACT We present the discovery of a pair of transiting giant planets using four sectors of TESS photometry. TOI-216 is a 0.87 M⊙ dwarf orbited by two transiters with radii of 8.2 and 11.3 R⊕, and periods of 17.01 and 34.57 d, respectively. Anticorrelated TTVs are clearly evident indicating that the transiters orbit the same star and interact via a near 2:1 mean motion resonance. By fitting the TTVs with a dynamical model, we infer masses of $30_{-14}^{+20}$ and $200_{-100}^{+170}$ M⊕, establishing that the objects are planetary in nature and have likely sub-Kronian and Kronian densities. TOI-216 lies close to the southern ecliptic pole and thus will be observed by TESS throughout the first year, providing an opportunity for continuous dynamical monitoring and considerable refinement of the dynamical masses presented here. TOI-216 closely resembles Kepler-9 in architecture, and we hypothesize that in such systems these Saturn analogues failed to fully open a gap and thus migrated far deeper into the system before becoming trapped into resonance, which would imply that future detections of new analogues may also have sub-Jupiter masses.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Li, Jianing, Huaping Wang, Juan Cui, Qing Shi, Zhiqiang Zheng, Tao Sun, Qiang Huang y Toshio Fukuda. "Magnetic Micromachine Using Nickel Nanoparticles for Propelling and Releasing in Indirect Assembly of Cell-Laden Micromodules". Micromachines 10, n.º 6 (1 de junio de 2019): 370. http://dx.doi.org/10.3390/mi10060370.

Texto completo

Resumen

Magnetic micromachines as wireless end-effectors have been widely applied for drug discovery and regenerative medicine. Yet, the magnetic assembly of arbitrarily shaped cellular microstructures with high efficiency and flexibility still remains a big challenge. Here, a novel clamp-shape micromachine using magnetic nanoparticles was developed for the indirect untethered bioassembly. With a multi-layer template, the nickel nanoparticles were mixed with polydimethylsiloxane (PDMS) for mold replication of the micromachine with a high-resolution and permeability. To actuate the micromachine with a high flexibility and large scalable operation range, a multi-pole electromagnetic system was set up to generate a three-dimensional magnetic field in a large workspace. Through designing a series of flexible translations and rotations with a velocity of 15mm/s and 3 Hz, the micromachine realized the propel-and-throw strategy to overcome the inevitable adhesion during bioassembly. The hydrogel microstructures loaded with different types of cells or the bioactive materials were effectively assembled into microtissues with reconfigurable shape and composition. The results indicate that indirect magnetic manipulation can perform an efficient and versatile bioassembly of cellular micromodules, which is promising for drug trials and modular tissue engineering.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Jamieson, Amy, Tjalling Bosse y Jessica N. McAlpine. "The emerging role of molecular pathology in directing the systemic treatment of endometrial cancer". Therapeutic Advances in Medical Oncology 13 (enero de 2021): 175883592110359. http://dx.doi.org/10.1177/17588359211035959.

Texto completo

Resumen

Following the discovery of the four molecular subtypes of endometrial cancer (EC) by The Cancer Genome Atlas (TCGA) in 2013, subsequent studies used surrogate markers to develop and validate a clinically relevant EC classification tool to recapitulate TCGA subtypes. Molecular classification combines focused sequencing ( POLE) and immunohistochemistry (mismatch repair and p53 proteins) to assign patients with EC to one of four molecular subtypes: POLEmut, MMRd, p53abn and NSMP (no specific molecular profile). Unlike histopathological evaluation, the molecular subtyping of EC offers an objective and reproducible classification system that has been shown to have prognostic value and therapeutic implications. It is an exciting time in EC care where we have moved beyond treatment based on histomorphology alone, and molecular classification will now finally allow assessment of treatment efficacy within biologically similar tumours. It is now recommended that molecular classification should be considered for all ECs, and should be performed routinely in all high grade tumours. It is also recommended to incorporate molecular classification into standard pathology reporting and treatment decision-making algorithms. In this review, we will discuss how the molecular classification of EC can be used to guide both conventional and targeted therapy in this new molecular era.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Randles, W. G. L. "The Emergence of Nautical Astronomy in Portugal in the XVth century". Journal of Navigation 51, n.º 1 (enero de 1998): 46–57. http://dx.doi.org/10.1017/s0373463397007674.

Texto completo

Resumen

Of the great oceans of the world, the Atlantic, because of its violence, was the last to be mastered by man. The task in its entirety had to wait for the Portuguese sailors of the Renaissance. Isidore of Seville (c. 570–636), a Christian writer of the late Roman Empire, had written of the Atlantic that it was ‘incommensurable and uncrossable’. Although Pliny (a.d. 23–79) refers vaguely to the Canary Islands, all knowledge of them disappears in the Middle Ages until a Portuguese expedition under the command of the Italian Lanzarotto Malocello ‘re- discovered’ them in 1336. Italian charts of the XIVth century begin progressively to show the Canaries, Madeira, Porto Santo and the Azores, but all aligned along a N/S axis without any appreciation of the relative distances between them or how far they lay from the European shore. The first written evidence of the Portuguese ‘discovery’ of the islands of Madeira and Porto Santo appears in 1419–20 and of the Azores in 1427, about the same time as they began to be colonised under the aegis of Prince Henry of Portugal, called the ‘Navigator’. The difficulties of returning to them on regular voyages was to motivate the Portuguese to develop methods of measurement using the Pole Star as a navigational aid and this led, not only to a greater accuracy in placing the islands on the charts, but also to a greater precision in the charting of the west African coastline which they were progressively exploring during the second half of the XVth century.Claims that Portuguese nautical astronomy originated in Aragon and was transmitted from there to Portugal or was introduced into Portugal from Germany by Regiomontanus and Martin Behaim have long ago been shown to be baseless.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Pole Discovery"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros