Academic literature on the topic 'Interval-based event'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Interval-based event.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Interval-based event"
1
Kang, Man-Mo, Sang-Mu Park, Sank-Rak Kim, Kang-Hyun Kim, and Dong-Hyeong Lee. "Detection of Complex Event Patterns over Interval-based Events." Journal of the Institute of Webcasting, Internet and Telecommunication 12, no. 4 (2012): 201–9. http://dx.doi.org/10.7236/jiwit.2012.12.4.201.
Full text
2
Helmer, Sven, and Fabio Persia. "ISEQL, an Interval-based Surveillance Event Query Language." International Journal of Multimedia Data Engineering and Management 7, no. 4 (2016): 1–21. http://dx.doi.org/10.4018/ijmdem.2016100101.
Full textAbstract:
The authors propose ISEQL, a language based on relational algebra extended by intervals for detecting high-level surveillance events from a video stream. The operators they introduce for describing temporal constraints are based on the well-known Allen's interval relationships and we implemented on top of a PostgreSQL database system. The semantics of ISEQL are clearly defined, and the authors illustrate its usefulness by expressing typical events in it and showing the promising results of an experimental evaluation.
3
Busany, Nimrod, Han Van Der Aa, Arik Senderovich, Avigdor Gal, and Matthias Weidlich. "Interval-based Queries over Lossy IoT Event Streams." ACM/IMS Transactions on Data Science 1, no. 4 (2020): 1–27. http://dx.doi.org/10.1145/3385191.
Full text
4
Govindasamy, V., and P. Thambidurai. "Heuristic Event Filtering Methodology for Interval based Temporal Semantics." International Journal of Computer Applications 70, no. 7 (2013): 16–20. http://dx.doi.org/10.5120/11974-7836.
Full text
5
Valente, Ana Rita S., Luis M. T. Jesus, Andreia Hall, and Margaret Leahy. "Event- and interval-based measurement of stuttering: a review." International Journal of Language & Communication Disorders 50, no. 1 (2014): 14–30. http://dx.doi.org/10.1111/1460-6984.12113.
Full text
6
Artikis, Alexander, Evangelos Makris, and Georgios Paliouras. "A probabilistic interval-based event calculus for activity recognition." Annals of Mathematics and Artificial Intelligence 89, no. 1-2 (2019): 29–52. http://dx.doi.org/10.1007/s10472-019-09664-4.
Full text
7
Smith, Jan. "Failure Interval Probabilistic Analysis for Risk-based Decisions - Concorde Crash Example." Journal of System Safety 56, no. 3 (2021): 46–55. http://dx.doi.org/10.56094/jss.v56i3.15.
Full textAbstract:
The DC-6, DC-8, DC-10, Concorde, Boeing 787 and Boeing 737 MAX fatal crashes and nearmisses were analyzed with event interval probabilistic analysis methods. Fleet grounding decisions are the epitome of risk-based decisions, and the most important decision is the first opportunity to ground. The “first opportunity to ground” decision is retrospectively judged to be wrong if, in the immediate future, another accident or cause-and-effect findings leads to the original decision being reversed. Using only data available at the time of the significant events, the analysis examines these risk-based decisions as if it they were made at the event’s instant in time.
 The event interval method identified five out of six “first opportunity to ground” decisions correctly, including the Concorde. According to these analyses, the FAA and its predecessor organizations made one correct decision out of five. Use of this method based on statistics and probability would have avoided 503 actual fatalities, plus 9.45 expected value fatalities from additional risk exposure due to flying statistically proven unreliable aircraft. In addition to the reversed decision standard for judging whether these decisions were wrong, the data show that a grounding of the DC-8 and a second grounding of the DC-6 would have been statistically appropriate — but these groundings did not occur.
 A specific objective of this paper is to lead the FAA and aircraft manufacturers to using event interval probabilistic analysis in grounding decisions and air-worthiness certification. The cause-and-effect data necessary to identify issues and make corrections are often sparse or nonexistent at the time of the event. Cause-and-effect data can take days or months to acquire and analyze, but event interval timing data are simple because system performance data are available at the instant the event occurs.
8
WANG, Peng, Xiaocong WANG, Nü'e XIAO, and Boyang LI. "Thermal runaway safety analysis of eVTOL based on evidence theory and interval analysis." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 42, no. 3 (2024): 558–66. http://dx.doi.org/10.1051/jnwpu/20244230558.
Full textAbstract:
In order to ensure the safety of eVTOL, safety analysis of thermal runaway problem of lithium battery is needed. Due to insufficient failure data, a safety assessment method based on evidence theory and interval analysis is proposed. Firstly, a fault tree model for system is constructed. Secondly, for the imprecise failure rate of bottom events in fault tree analysis, the failure probability interval of bottom event is calculated by using the evidence theory, and combining with the importance analysis to address the problem of inaccurate failure rate of bottom events in fault tree analysis. The evidence theory is used to calculate the probability interval of failure of bottom events and combine it with interval theory to calculate the top events of the fault tree. Finally, the importance analysis is used to find out the basic events that have the greatest impact on the top events. The proposed method is used to analyze the safety of the eVTOL′s battery thermal runaway and calculate the importance of each bottom event, so as to provide a basis for reducing the system failure probability and improving the system safety level.
9
Zhou, Chunjie, Pengfei Dai, Zhenxing Zhang, and Tong Liu. "Interval-Based Out-of-Order Event Processing in Intelligent Manufacturing." Journal of Intelligent Learning Systems and Applications 10, no. 02 (2018): 21–35. http://dx.doi.org/10.4236/jilsa.2018.102002.
Full text
10
., Kubra Iram. "SEQUENTIAL TEMPORAL PATTERN MINING IN TIME-INTERVAL BASED EVENT DATA." International Journal of Research in Engineering and Technology 05, no. 16 (2016): 48–52. http://dx.doi.org/10.15623/ijret.2016.0516011.
Full textDissertations / Theses on the topic "Interval-based event"
1
Batarseh, Ola. "AN INTERVAL BASED APPROACH TO MODEL INPUT UNCERTAINTY IN DISCRETE-EVENT SIMULATION." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2540.
Full textAbstract:
The objective of this research is to increase the robustness of discrete-event simulation (DES) when input uncertainties associated models and parameters are present. Input uncertainties in simulation have different sources, including lack of data, conflicting information and beliefs, lack of introspection, measurement errors, and lack of information about dependency. A reliable solution is obtained from a simulation mechanism that accounts for these uncertainty components in simulation. An interval-based simulation (IBS) mechanism based on imprecise probabilities is proposed, where the statistical distribution parameters in simulation are intervals instead of precise real numbers. This approach incorporates variability and uncertainty in systems. In this research, a standard procedure to estimate interval parameters of probability distributions is developed based on the measurement of simulation robustness. New mechanisms based on the inverse transform to generate interval random variates are proposed. A generic approach to specify the required replication length to achieve a desired level of robustness is derived. Furthermore, three simulation clock advancement approaches in the interval-based simulation are investigated. A library of Java-based IBS toolkits that simulates queueing systems is developed to demonstrate the new proposed reliable simulation. New interval statistics for interval data analysis are proposed to support decision making. To assess the performance of the IBS, we developed an interval-based metamodel for automated material handling systems, which generates interval performance measures that are more reliable and computationally more efficient than traditional DES simulation results.<br>Ph.D.<br>Department of Industrial Engineering and Management Systems<br>Engineering and Computer Science<br>Industrial Engineering PhD
2
Kawashima, Hiroaki. "Interval-Based Hybrid Dynamical System for Modeling Dynamic Events and Structures." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/68896.
Full text
3
Cheng-WeiYang and 楊鄭緯. "Subsequence Search in Time Interval-based Event Sequences with Duration Match and Event Match." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6vj4xa.
Full text
4
Kuan-YingChen and 陳冠穎. "Mining Frequent and Top-K High Utility Time Interval-based Event with Duration Patterns from Temporal Database." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/73130083923608974912.
Full textAbstract:
碩士<br>國立成功大學<br>電腦與通信工程研究所<br>102<br>Time interval-based pattern mining is proposed to improve the lack of the information of time intervals by sequential pattern mining. Previous works of time interval-based pattern mining focused on the relations between events without considering the duration of each event. However,
the same event with different time durations will cause definitely different results. For example, if some patients cough for one day, they may get a cold for one week. In contrast, if some patients cough for one year, they may get pneumonia in the future. In this work, we propose two algorithms, SARA and SARS, to extract the frequent Time Interval-based Event with Duration, TIED, patterns. TIED patterns not only keep the relations between two events
but also reveal the time periods when each event happens and ends. In the experiments, we propose a naive algorithm and modify a previous algorithm to compare the performances with
SARA and SARS. The experimental results show that SARA and SARS are more efficient in execution time and memory usage than other two algorithms. Otherwise, TIED pattern still
has limitation, which do not consider the utility value in each time stamp. We propose another pattern, High Utility Time Interval-based with Duration Pattern, which combine the concept of utility pattern mining and TIED pattern mining. We design an algorithm, LMSpan, to mine High Utility Time Interval-based with Duration, HU-TIED, Pattern. In the experiments, we design another naive algorithm, Naive UDP to compare with LMSpan. LMSpan take less time and memory use and generate less candidate than Naive UDP.
5
"Discovering temporal patterns for interval-based events." 2000. http://library.cuhk.edu.hk/record=b5890407.
Full textAbstract:
Kam, Po-shan.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.<br>Includes bibliographical references (leaves 89-97).<br>Abstracts in English and Chinese.<br>Abstract --- p.i<br>Acknowledgements --- p.ii<br>Chapter 1 --- Introduction --- p.1<br>Chapter 1.1 --- Data Mining --- p.1<br>Chapter 1.2 --- Temporal Data Management --- p.2<br>Chapter 1.3 --- Temporal reasoning and temporal semantics --- p.3<br>Chapter 1.4 --- Temporal Data Mining --- p.5<br>Chapter 1.5 --- Motivation --- p.6<br>Chapter 1.6 --- Approach --- p.7<br>Chapter 1.6.1 --- Focus and Objectives --- p.8<br>Chapter 1.6.2 --- Experimental Setup --- p.8<br>Chapter 1.7 --- Outline and contributions --- p.9<br>Chapter 2 --- Relevant Work --- p.10<br>Chapter 2.1 --- Data Mining --- p.10<br>Chapter 2.1.1 --- Association Rules --- p.13<br>Chapter 2.1.2 --- Classification --- p.15<br>Chapter 2.1.3 --- Clustering --- p.16<br>Chapter 2.2 --- Sequential Pattern --- p.17<br>Chapter 2.2.1 --- Frequent Patterns --- p.18<br>Chapter 2.2.2 --- Interesting Patterns --- p.20<br>Chapter 2.2.3 --- Granularity --- p.21<br>Chapter 2.3 --- Temporal Database --- p.21<br>Chapter 2.4 --- Temporal Reasoning --- p.23<br>Chapter 2.4.1 --- Natural Language Expression --- p.24<br>Chapter 2.4.2 --- Temporal Logic Approach --- p.25<br>Chapter 2.5 --- Temporal Data Mining --- p.25<br>Chapter 2.5.1 --- Framework --- p.25<br>Chapter 2.5.2 --- Temporal Association Rules --- p.26<br>Chapter 2.5.3 --- Attribute-Oriented Induction --- p.27<br>Chapter 2.5.4 --- Time Series Analysis --- p.27<br>Chapter 3 --- Discovering Temporal Patterns for interval-based events --- p.29<br>Chapter 3.1 --- Temporal Database --- p.29<br>Chapter 3.2 --- Allen's Taxonomy of Temporal Relationships --- p.31<br>Chapter 3.3 --- "Mining Temporal Pattern, AppSeq and LinkSeq" --- p.33<br>Chapter 3.3.1 --- A1 and A2 temporal pattern --- p.33<br>Chapter 3.3.2 --- "Second Temporal Pattern, LinkSeq" --- p.34<br>Chapter 3.4 --- Overview of the Framework --- p.35<br>Chapter 3.4.1 --- "Mining Temporal Pattern I, AppSeq" --- p.36<br>Chapter 3.4.2 --- "Mining Temporal Pattern II, LinkSeq" --- p.36<br>Chapter 3.5 --- Summary --- p.37<br>Chapter 4 --- "Mining Temporal Pattern I, AppSeq" --- p.38<br>Chapter 4.1 --- Problem Statement --- p.38<br>Chapter 4.2 --- Mining A1 Temporal Patterns --- p.40<br>Chapter 4.2.1 --- Candidate Generation --- p.43<br>Chapter 4.2.2 --- Large k-Items Generation --- p.46<br>Chapter 4.3 --- Mining A2 Temporal Patterns --- p.48<br>Chapter 4.3.1 --- Candidate Generation: --- p.49<br>Chapter 4.3.2 --- Generating Large 2k-Items: --- p.51<br>Chapter 4.4 --- Modified AppOne and AppTwo --- p.51<br>Chapter 4.5 --- Performance Study --- p.53<br>Chapter 4.5.1 --- Experimental Setup --- p.53<br>Chapter 4.5.2 --- Experimental Results --- p.54<br>Chapter 4.5.3 --- Medical Data --- p.58<br>Chapter 4.6 --- Summary --- p.60<br>Chapter 5 --- "Mining Temporal Pattern II, LinkSeq" --- p.62<br>Chapter 5.1 --- Problem Statement --- p.62<br>Chapter 5.2 --- "First Method for Mining LinkSeq, LinkApp" --- p.63<br>Chapter 5.3 --- "Second Method for Mining LinkSeq, LinkTwo" --- p.64<br>Chapter 5.4 --- "Alternative Method for Mining LinkSeq, LinkTree" --- p.65<br>Chapter 5.4.1 --- Sequence Tree: Design --- p.65<br>Chapter 5.4.2 --- Construction of seq-tree --- p.69<br>Chapter 5.4.3 --- Mining LinkSeq using seq-tree --- p.76<br>Chapter 5.5 --- Performance Study --- p.82<br>Chapter 5.6 --- Discussions --- p.85<br>Chapter 5.7 --- Summary --- p.85<br>Chapter 6 --- Conclusion and Future Work --- p.87<br>Chapter 6.1 --- Conclusion --- p.87<br>Chapter 6.2 --- Future Work --- p.88<br>Bibliography --- p.97
Books on the topic "Interval-based event"
1
Pfurtscheller, Gert, and Fernando Lopes da Silva. EEG Event-Related Desynchronization and Event-Related Synchronization. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0040.
Full textAbstract:
Event-related desynchronization (ERD) reflects a decrease of oscillatory activity related to internally or externally paced events. The increase of rhythmic activity is called event-related synchronization (ERS). They represent dynamical states of thalamocortical networks associated with cortical information-processing changes. This chapter discusses differences between ERD/ERS and evoked response potentials and methodologies for quantifying ERD/ERS and selecting frequency bands. It covers the interpretation of ERD/ERS in the alpha and beta bands and theta ERS and alpha ERD in behavioral tasks. ERD/ERS in scalp and subdural recordings, in various frequency bands, is discussed. Also presented is the modulation of alpha and beta rhythms by 0.1-Hz oscillations in the resting state and phase-coupling of the latter with slow changes of prefrontal hemodynamic signals (HbO2), blood pressure oscillations, and heart rate interval variations in the resting state and in relation to behavioral motor tasks. Potential uses of ERD-based strategies in stroke patients are discussed.
Book chapters on the topic "Interval-based event"
1
Carlson, Jan, and Björn Lisper. "An Interval-Based Algebra for Restricted Event Detection." In Lecture Notes in Computer Science. Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-40903-8_10.
Full text
2
Plantevit, Marc, Vasile-Marian Scuturici, and Céline Robardet. "Temporal Dependency Detection Between Interval-Based Event Sequences." In New Frontiers in Mining Complex Patterns. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-17876-9_9.
Full text
3
Adaikkalavan, Raman, and Sharma Chakravarthy. "SnoopIB: Interval-Based Event Specification and Detection for Active Databases." In Advances in Databases and Information Systems. Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-39403-7_16.
Full text
4
Sulskus, Gintautas, Michael Poppleton, and Abdolbaghi Rezazadeh. "An Interval-Based Approach to Modelling Time in Event-B." In Fundamentals of Software Engineering. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-24644-4_20.
Full text
5
Zhou, Chunjie, and Xiaofeng Meng. "IO3: Interval-Based Out-of-Order Event Processing in Pervasive Computing." In Database Systems for Advanced Applications. Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12098-5_20.
Full text
6
Wang, Xinglong, and Youjie Wang. "Multi-rotor eVTOL Safety Interval Assessment Based on Improved Event Model." In Engineering Psychology and Cognitive Ergonomics. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-60731-8_23.
Full text
7
Mirbagheri, S. Mohammad. "A Projected Upper Bound for Mining High Utility Patterns from Interval-Based Event Sequences." In Recent Challenges in Intelligent Information and Database Systems. Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-42430-4_30.
Full text
8
Alharbi, Amirah, Andy Bulpitt, and Owen Johnson. "Improving Pattern Detection in Healthcare Process Mining Using an Interval-Based Event Selection Method." In Lecture Notes in Business Information Processing. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65015-9_6.
Full text
9
Rodriguez, Luis Garcia, Jonas Konrad, Dominik Drees, and Benjamin Risse. "S-ROPE: Spectral Frame Representation of Periodic Events." In Lecture Notes in Computer Science. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-92460-6_19.
Full textAbstract:
Abstract In this paper we introduce a novel event surface representation designed for encoding temporal information of dynamic vision sensors (DVS) into a multi-channel frame format. Different representations have been proposed to extract features from event streams. Among these representations, time surfaces have become a popular choice due to their ability to provide a flattened view of event data over a specified time interval. Despite their widespread adaption, these methods suffer from loss of crucial temporal information. This disadvantage is particularly apparent in DVS applications with repetitive, high-frequency intensity changes, as these signals result in continuously elevated event rates and would therefore benefit from efficient, yet information preserving representations. Moreover, integrating this information into state-of-the-art vision-based machine learning models remains challenging. To address these limitations, we propose Spectral frame Representation of Periodic Events (S-ROPE) which leverages information from frequency domain analysis through the application of the Fourier transformation and arranges the resulting frequency, amplitude and phase into spatially consistent frames. By transforming event streams from the temporal domain to the frequency domain, we demonstrate improved preservation of temporal dynamics, especially for objects displaying high frequency oscillations. We evaluate S-ROPE frames on custom and several publicly available datasets and demonstrate the applicability for three distinct use cases: visualisation, compression and machine learning-based image processing. For the latter, we show that S-ROPE proves useful for object detection in a scenery with high frequency events.
10
Kam, Po-shan, and Ada Wai-chee Fu. "Discovering Temporal Patterns for Interval-based Events." In Data Warehousing and Knowledge Discovery. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/3-540-44466-1_32.
Full textConference papers on the topic "Interval-based event"
1
Sheng, Guangyu, and Chao Sun. "Sensor Fault Estimation Based on Dynamic Event-triggered Mechanism and Interval Observer." In 2024 6th International Conference on Industrial Artificial Intelligence (IAI). IEEE, 2024. http://dx.doi.org/10.1109/iai63275.2024.10730031.
Full text
2
Li, Junshen, Haiyang Ren, Zhengyu Liao, et al. "DI-Tree: A Dual-ended Interval Tree for Efficient Event Matching in Content-based Pub/Sub Systems." In 2024 IEEE 30th International Conference on Parallel and Distributed Systems (ICPADS). IEEE, 2024. http://dx.doi.org/10.1109/icpads63350.2024.00068.
Full text
3
Case, Raymundo. "Assessment of CO2 Corrosion Damage Distribution in Oilwells by Deterministic and Stochastical Modelling." In CORROSION 2008. NACE International, 2008. https://doi.org/10.5006/c2008-08541.
Full textAbstract:
Abstract In the present paper, an a priori corrosion damage distribution assessment methodology is implemented to study the production casing failures observed in oilwells operating within a mature oilfield (Oritupano A, Venezuela). The methodology developed aims at the assessment of corrosion damage and subsequent probability of failure. The study approach is based on the mechanistic modelling of CO2 corrosion coupled with a stochastical simulation for the associated corrosion damage distribution The stochastical model developed for the assessment of the corrosion related damage distribution was based on the simulation of the CO2 corrosion mechanisms. The results obtained from the evaluation of the model proposed shows that it can quantitatively indicate the transition from uniform damage distribution to localized forms of CO2 corrosion attack. The modelling methodology proposed was used to calculate the survival probability curves for the production casing, exposed to the produced fluids from the Oritupano A field, in both vertical and deviated wells. The results obtained indicate that the deviated wells can experience a casing failure event every 6 years of service time; in contrast, the vertical wells show a much higher failure time interval. These results were validated with the actual workover information from the field.
4
Fletcher, Toby, and Farid Samie. "Application of Statistical Modeling of Pipeline Corrosion Defects." In CORROSION 2014. NACE International, 2014. https://doi.org/10.5006/c2014-4032.
Full textAbstract:
Abstract Defects in pipelines may corrode further and grow larger over time. Eventually the size of such defects may threaten the integrity of pipelines and result in expensive repairs, replacements or even abandonment. Predicting the growth of defects allows operators to assess how long pipelines may be safely operated and to actively manage integrity. Current assessment methodologies commonly apply a single, linear corrosion growth rate to all defects in a pipeline in their depth-based dimension only. The acceptability of defects at a given time interval is assessed and used to prioritize mitigations such as in-line inspection frequencies or repair schedules. The method presented in this paper describes an alternative way of predicting the growth of corrosion defects in three dimensions by the application of statistical modeling. This method may be used to predict the increase in axial size, circumferential size and depth of a defect for any given time interval; this enables the acceptability of groups of defects that are predicted to interact to be assessed.
5
Parker, Keith, Christophe Baete, and Trey Johnston. "Validating Digital Twin Model of a Complex Pipeline System." In CONFERENCE 2023. AMPP, 2023. https://doi.org/10.5006/c2023-18958.
Full textAbstract:
Abstract Operating a pipeline requires regular field surveys for controlling external corrosion threats. Surveys are typically performed at rectifiers and test stations, and occasionally a close interval survey between test stations is performed. Pipeline surveys provide only an indirect measure of the corrosion threat and are either labor intensive or do not provide sufficient granularity and accuracy to pinpoint corrosion features in a timely manner. A computational model of the primary and third party (crossing) pipelines and associated cathodic protection systems is built and further calibrated to accurately simulate protection status based on survey and monitoring data. The resulting digital twin is a replica of the real-world condition with a resolution at pipeline joint level for its full pipeline length. Fluctuations in field data are captured and translated into IR-free potentials and corrosion rate distribution at coating defects along the pipeline. This article discusses a case study of a calibrated digital twin model of a complex pipeline system. Back testing based on historical survey data was performed to identify events on the pipeline that increase the corrosion risk. The digital model will be used to improve the corrosion prevention strategy within an integrated external corrosion management program.
6
Ormellese, Marco, Andrea Brenna, and Luciano Lazzari. "AC Corrosion of Cathodically Protected Buried Pipelines: Critical Interference Values and Protection Criteria." In CORROSION 2015. NACE International, 2015. https://doi.org/10.5006/c2015-05753.
Full textAbstract:
Abstract Carbon steel pipes used to transport hydrocarbons and dangerous fluids are provided with corrosion prevention systems, namely an insulating coating and a cathodic protection (CP) system which reduces (or halts) corrosion rate below 10 µm/y, which is the maximum accepted corrosion according to standards. The presence of AC interference may cause serious corrosion damage on metallic structures, even under CP condition. AC interference can take place by a conduction or an induction mechanism causing corrosion corresponding to coating defects, even if the -0.850 V CSE criterion is matched. Field failures and laboratory investigations have confirmed that at industrial AC frequencies (50 or 60 Hz) corrosion can occur even if CP is correctly applied and that AC corrosion is less than that caused by the equivalent direct current. Nevertheless, uncertainties still exist on protection potential interval to reach acceptable corrosion protection if AC interference is present. In order to assess CP criteria in the presence of AC, weight loss tests on cathodically protected carbon steel specimens were carried out in soil-simulated conditions in the presence of AC densities ranging from 1 to about 800 A/m2. Samples were cathodically polarised in the presence of AC interference for four months: protection potential, protection current density and AC density were periodically monitored. Based on experimental results, a corrosion risk map is proposed: overprotection (potential more negative than -1.1 V CSE) seems to be the most dangerous condition in the presence of AC.
7
Dugarte, M., A. A. Sagüés, and K. Williams. "Cathodic Prevention for Reinforcing Steel in Cracked Concrete of Chloride Contaminated Structures." In CORROSION 2015. NACE International, 2015. https://doi.org/10.5006/c2015-06102.
Full textAbstract:
Abstract Steel in concrete in marine service corrodes actively when chloride ion concentration exceeds a critical threshold level, CT, causing passive film breakdown. There is interest in alternative or supplemental corrosion management approaches to extend structural life. One such approach is Cathodic Prevention (CPrev), based on the increase of CT when steel is polarized in the cathodic direction while still in the passive condition. This work seeks to determine the effectiveness of cathodic prevention on cracked concrete in a marine environment. Experiments use reinforced concrete blocks with controlled-width cracks placed along the length of a central reinforcing steel bar, with initial cyclic exposure to a 5% NaCl solution. Crack widths ranging from 0.01 in to 0.04 in and polarization levels ranging from -330 mV to -540 mV (SCE) were evaluated over 1 year. Results suggest that CPrev with moderate cathodic polarization levels may be of limited benefit in the presence of the lengthwise cracks. Polarization at potentials ≥ -430 mV SCE was insufficient to prevent corrosion initiation in cracks of any of the tested sizes. Polarization at the stronger -540 mV SCE regime resulted in no corrosion initiation events for any crack size during the one-year test interval.
8
King, Fraser, Peter Robinson, Claire Watson, Jenny Burrow, and Cristiano Padovani. "ACSIS – A Model to Assess the Potential for Atmospheric Corrosion of Stainless Steel ILW Containers During Storage and the Operational Phase of a UK Geological Disposal Facility." In CORROSION 2013. NACE International, 2013. https://doi.org/10.5006/c2013-02717.
Full textAbstract:
Abstract A model has been developed to assess the potential for atmospheric corrosion of stainless steel ILW containers in storage and during the operational phase of a geological disposal facility (GDF) in the UK. The model has been implemented in custom-designed software, Atmospheric Corrosion of Stainless Steel in Stores (ACSIS), which can be used to assess the extent of localized corrosion and stress corrosion cracking and, equally importantly, to inform store designers and operators how to avoid atmospheric corrosion through appropriate control of environmental conditions. The model accounts for the initiation and propagation of localized corrosion (either pitting or crevice corrosion) and stress corrosion cracking (SCC) of austenitic or duplex stainless steel containers as a result of the deliquescence of surface salt contaminants. The model first characterizes the time-dependent nature of the corrosive environment in terms of the duration of, and interval between, wetting events based on temperature and relative humidity data from the store or GDF and knowledge of the nature of the surface contaminant. Various criteria are used to determine whether localized corrosion and/or SCC initiate during a given wetting episode and, if initiation does occur, the extent of damage that may result. The output of the model includes the number of corrosion episodes and the depth of the pit, crevice, and/or crack.
9
Brendel, William, Alan Fern, and Sinisa Todorovic. "Probabilistic event logic for interval-based event recognition." In 2011 IEEE Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2011. http://dx.doi.org/10.1109/cvpr.2011.5995491.
Full text
10
Saleme, Estêvão Bissoli, Celso A. S. Santos, and Gheorghita Ghinea. "Improving response time interval in networked event-based mulsemedia systems." In MMSys '18: 9th ACM Multimedia Systems Conference. ACM, 2018. http://dx.doi.org/10.1145/3204949.3204965.
Full textReports on the topic "Interval-based event"
1
Correia, V., R. A. Fensome, R. A. MacRae, L. T. Dafoe, and G. L. Williams. Mesozoic event-stratigraphy of the Scotian Margin, offshore Nova Scotia: preliminary palynological results from the Upper Member of the Missisauga Formation in Panuke B-90. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331910.
Full textAbstract:
Conceived as a continuation of the previous multidisciplinary event stratigraphy studies of the Late Cretaceous to Neogene of the Scotian Margin in the 2000s, the "Mesozoic eventstratigraphy of the Scotian Margin" project proposes a similar study for the Late Triassic to Early Cretaceous interval. The first stage of this project comprises a detailed multidisciplinary study of the composite Lower Cretaceous section from Panuke B-90 and Cohasset A-52 conventional cores. The present work reports initial palynologic data from the formal Upper Member of the Missisauga Formation in Panuke B-90. These data, combined with preliminary insights from sedimentary facies, macrofossil, and trace fossil analyses, suggest that from the base of the studied section upwards involves a transition from a neritic/shelfal to a mainly estuarine-brackish setting. This was followed by a transgressive cycle through the Upper Member of the Missisauga Formation, which culminated in a return of more fully marine environments near the base of the overlying Naskapi Member of the Logan Canyon Formation. It is apparent that this transgression is not continuous, but intercalated with smaller cycles, well documented by the fluctuations in dominance between terrestrial (pollen and spore abundance) versus marine (mainly dinoflagellate-cyst abundance and richness) palynomorph trends through this succession, presented here in three main intervals. The dinoflagellate-cyst assemblages and key bioevents recorded in this initial study indicate a Barremian age for the Upper Member of the Missisauga Formation in Panuke B-90. The overlying Naskapi Member is expected to be of early Aptian age based on previous reports of the presence of the age-diagnostic ammonite Deshayesites sp. Ongoing work on the conventional cores from Panuke B-90, and subsequently Cohasset A-52 and other wells, will contribute to a comprehensive Mesozoic event-stratigraphic framework for the Scotian Margin.
2
Nessim. L51765 Offshore and Onshore Design Application. Pipeline Research Council International, Inc. (PRCI), 1997. http://dx.doi.org/10.55274/r0010622.
Full textAbstract:
This report describes the results of a research project on reliability-based optimization of pipeline integrity maintenance activities. The objective was to develop models to quantify the effect of different maintenance activities on the structural reliability of pipelines, and to demonstrate how these models can be used in a relaibility-based framework to develop optimal integrity maintenance plans. The approaches developed can be used to prioritize pipeline segments for maintenance and to select the optimal combination of activites for high priority segments. The maintenance decisions considered include the mainteance method, the time interval between events, and the repair criteria for damage detected by inspection. This report also documents the development of a methodology to quantify the effect of maintenance activities on the structural reliability of pipeline systems.
3
Nessim, M. A., and M. D. Pandey. PR-244-9519-R01 Reliability Based Planning of Inspection and Maintenance of Pipeline Integrity. Pipeline Research Council International, Inc. (PRCI), 1997. http://dx.doi.org/10.55274/r0011956.
Full textAbstract:
This report describes the results of a research project on the reliability-based optimization of pipeline integrity maintenance activities. The objective of the project was to develop models to quantify the effect of different maintenance activities on the structural reliability of pipelines and to demonstrate how the results of these models can be used in a reliability-based framework to develop optimal integrity maintenance plans. The approaches developed can be used to prioritize different pipeline segments for maintenance and to select the optimal combination of integrity maintenance actions for high priority segments. The maintenance decisions considered for a given pipeline segment include the maintenance method, the time interval between maintenance events, and the repair criteria for damage detected by inspection.
4
Selph, Shelley S., Andrea C. Skelly, Tracy Dana, et al. Psychosocial and Pharmacologic Interventions for Disruptive Behavior in Children and Adolescents: A Systematic Review. Agency for Healthcare Research and Quality, 2025. https://doi.org/10.23970/ahrqepcsrdisruptive.
Full textAbstract:
Objectives. To determine the most effective treatments for clinically significant disruptive behaviors in children and adolescents. Data sources. Ovid® MEDLINE®, the Cochrane Library, PsycINFO®, and Embase® databases were searched from 2014 to July 22, 2024. Additionally, we reviewed all studies included in the prior 2015 Agency for Healthcare Research and Quality review. Review methods. We dual reviewed abstracts and full-text articles; data extraction was checked by a second reviewer; risk of bias and strength of evidence were assessed by two reviewers; and disagreements were resolved by consensus. Results. For this review, 168 studies in 194 publications (160 randomized controlled trials [RCTs] and 8 nonrandomized studies) met inclusion criteria. Psychosocial interventions: Multicomponent interventions (parent or teacher plus child) substantially reduced parent-reported disruptive behavior more than usual care or waitlist in preschool children (10 RCTs, N=784, standard mean difference [SMD] -0.96, 95% confidence interval [CI] -1.39 to -0.60) and moderately reduced disruptive behavior in school-age children (9 RCTs, N=524, SMD -0.61, 95% CI -1.05 to -0.20) immediately posttreatment. Similarly, interventions that involved the parent only and not the child also moderately reduced parent-reported disruptive behavior in preschool children (13 RCTs, N=1,222, SMD -0.61, 95% CI 0.99 to -0.31) and slightly reduced disruptive behavior in school-age children (11 RCTs, N=1,289, SMD 0.39, 95% CI 0.58 to 0.22). Comparisons between psychosocial interventions generally showed only minor differences in disruptive behaviors in preschool and school-age children. Findings in adolescents for multicomponent and child-only interventions versus usual care and waitlist and versus another intervention were mixed. Through pairwise, indirect, and network meta-analyses, we were not able to determine whether multicomponent, parent-only, or child-only interventions are superior overall, though there was less evidence in child-only interventions and interventions in adolescents. Pharmacologic interventions: There was limited evidence to support the use of stimulants and/or antipsychotics for disruptive behavior disorders in selected children. Treatment response was more likely with stimulant treatment alone (2 RCTs) and in pooled analysis of add-on risperidone (2 RCTs) and risperidone maintenance (1 RCT) compared with placebo. Study withdrawal due to adverse events was higher with any pharmacotherapy relative to placebo (6 RCTs, N=911, RR 3.44, 95% CI 1.35 to 8.75), although serious adverse events were rare and not different from placebo. Evidence was insufficient to determine whether psychosocial, pharmacological, or a combination of psychological and pharmacological interventions are more effective in reducing disruptive behaviors in children and adolescents. Evidence was also inconsistent or insufficient to determine if benefits and harms of treatment interventions varied based on patient, clinical, or treatment characteristics, or treatment history. Conclusions. Multicomponent psychosocial interventions (parent or teacher plus child) and parent-only psychosocial interventions were better than treatment as usual or waitlist at reducing parent report of child disruptive behaviors for preschool and school-age children immediately post-treatment. In these children, direct and indirect comparisons of multicomponent, parent-only, and child-only interventions generally found no or only minor differences in reducing disruptive behaviors, although effectiveness differed by specific psychosocial intervention. Results of multicomponent interventions and child-only interventions were mixed in adolescents and studies in adolescents were few. Pharmacotherapy may be helpful in reducing disruptive behaviors in some children who have inadequate response to psychosocial interventions. The use of medications was associated with an increased risk of experiencing any adverse event, but serious adverse events were infrequent and similar to placebo. For all age groups, evidence for some psychosocial interventions and all pharmacological interventions was limited, as was reporting of long-term outcomes. Additional research is needed to aid the clinician in selecting the intervention most likely to be effective in reducing disruptive behaviors well beyond treatment completion.
5
Gadd, M. G., J. M. Peter, T A Fraser, and D. Layton-Matthews. Paleoredox and lithogeochemical indicators of the environment of formation and genesis of the Monster River hyper-enriched black shale showing, Yukon. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328004.
Full textAbstract:
Northern Yukon hosts occurrences of Middle Devonian hyper-enriched black shale (HEBS) Ni-Mo-Zn-platinum-group element-Au-Re mineralization, including the Monster River showing in the Ogilvie Mountains. This mineralization has been documented predominantly in the Paleozoic Richardson trough; however, the Monster River showing is atypical, occurring within the Blackstone trough, more than 200 km to the west on the southern margin of the Yukon block. The ambient paleoredox conditions of the marine water column and sediments may be primary controlling factors in HEBS formation. We use major and trace element lithogeochemistry to better understand ambient paleoenvironmental redox conditions through the application of robust redox proxies to HEBS mineralization and host rocks. Uniformly negative Ce anomalies (0.6-0.9) indicate that the water column was predominantly suboxic throughout the deposition interval, even during HEBS mineralization. Although there is a strong terrigenous influence on the rare earth element-yttrium (REE-Y) abundances of the sedimentary rocks, superchondritic Y/Ho ratios (&amp;gt;27) indicate that seawater contributed REE-Y to the host rocks and HEBS. High (&amp;gt;10) authigenic Mo/U ratios indicate that a Fe-Mn particulate shuttle operated in the water column; this is corroborated by negative Ce anomalies and high Y/Ho ratios. The data indicate that metalliferous sedimentary rocks formed by hydrogenous metal enrichment (e.g. Ni, Mo, Pt) caused by ferromanganese oxyhydroxide particulate shuttling as chemical sediments; moreover, the REE- and Mo-based paleoenvironmental indicators suggest a complexly redox-stratified depositional environment with an abundant supply of metals, metalloids, and sulfur.
6
Chou, Roger, Jesse Wagner, Azrah Y. Ahmed, et al. Living Systematic Review on Cannabis and Other Plant-Based Treatments for iii Chronic Pain: 2022 Update. Agency for Healthcare Research and Quality (AHRQ), 2022. http://dx.doi.org/10.23970/ahrqepccer250update2022.
Full textAbstract:
Objectives. To update the evidence on benefits and harms of cannabinoids and similar plant-based compounds to treat chronic pain using a living systematic review approach. Data sources. Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Library, and SCOPUS® databases; reference lists of included studies; and submissions received after Federal Register request were searched to April 4, 2022. Review methods. Using dual review, we screened search results for randomized controlled trials (RCTs) and observational studies of patients with chronic pain evaluating cannabis, kratom, and similar compounds with any comparison group and at least 1 month of treatment or followup. Dual review was used to abstract study data, assess study-level risk of bias, and rate the strength of evidence (SOE). Prioritized outcomes included pain, overall function, and adverse events. We grouped studies that assessed tetrahydrocannabinol (THC) and/or cannabidiol (CBD) based on their THC to CBD ratio and categorized them as comparable THC to CBD ratio, high-THC to CBD ratio, and low-THC to CBD ratio. We also grouped studies by whether the product was a whole-plant product (cannabis), cannabinoids extracted or purified from a whole plant, or a synthetic product. We conducted meta-analyses using the profile likelihood random effects model and assessed between-study heterogeneity using Cochran’s Q statistic chi square test and the I2 statistic. Magnitude of benefit was categorized as no effect or small, moderate, and large effects. Results. From 3,283 abstracts, 21 RCTs (N=1,905) and 8 observational studies (N=13,769) assessing different cannabinoids were included; none evaluated kratom. Studies were primarily short term, and 59 percent enrolled patients with neuropathic pain. Comparators were primarily placebo or usual care. The SOE was low unless otherwise noted. Compared with placebo, comparable THC to CBD ratio oral spray was associated with a small benefit in change in pain severity (7 RCTs, N=632, 0 to10 scale, mean difference [MD] −0.54, 95% confidence interval [CI] −0.95 to −0.19, I2=39%; SOE: moderate) and overall function (6 RCTs, N=616, 0 to 10 scale, MD −0.42, 95% CI −0.73 to −0.16, I2=32%). There was no effect on study withdrawals due to adverse events. There was a large increased risk of dizziness and sedation, and a moderate increased risk of nausea (dizziness: 6 RCTs, N=866, 31.0% vs. 8.0%, relative risk [RR] 3.57, 95% CI 2.42 to 5.60, I2=0%; sedation: 6 RCTs, N=866, 8.0% vs. 1.2%, RR 5.04, 95% CI 2.10 to 11.89, I2=0%; and nausea: 6 RCTs, N=866, 13% vs. 7.5%, RR 1.79, 95% CI 1.19 to 2.77, I2=0%). Synthetic products with high-THC to CBD ratios were associated with a moderate improvement in pain severity, a moderate increase in sedation, and a large increase in nausea (pain: 6 RCTs, N=390, 0 to 10 scale, MD −1.15, 95% CI −1.99 to −0.54, I2=48%; sedation: 3 RCTs, N=335, 19% vs. 10%, RR 1.73, 95% CI 1.03 to 4.63, I2=28%; nausea: 2 RCTs, N=302, 12.3% vs. 6.1%, RR 2.19, 95% CI 0.77 to 5.39; I²=0%). We also found moderate SOE for a large increased risk of dizziness (2 RCTs, 32% vs. 11%, RR 2.74, 95% CI 1.47 to 6.86, I2=40%). Extracted whole-plant products with high-THC to CBD ratios (oral) were associated with a large increased risk of study withdrawal due to adverse events (1 RCT, 13.9% vs. 5.7%, RR 3.12, 95% CI 1.54 to 6.33) and dizziness (1 RCT, 62.2% vs. 7.5%, RR 8.34, 95% CI 4.53 to 15.34); outcomes assessing benefit were not reported or insufficient. We observed a moderate improvement in pain severity when combining all studies of high-THC to CBD ratio (8 RCTs, N=684, MD −1.25, 95% CI −2.09 to −0.71, I2=58%; SOE: moderate). Evidence (including observational studies) on whole-plant cannabis, topical or oral CBD, low-THC to CBD, other cannabinoids, comparisons with active products or between cannabis-related products, and impact on use of opioids was insufficient to draw conclusions. Other important harms (psychosis, cannabis use disorder, and cognitive effects) were not reported. Conclusions. Low to moderate strength evidence suggests small to moderate improvements in pain (mostly neuropathic), and moderate to large increases in common adverse events (dizziness, sedation, nausea) with high- and comparable THC to CBD ratio extracted cannabinoids and synthetic products during short-term treatment (1 to 6 months); high-THC to CBD ratio products were also associated with increased risk of withdrawal due to adverse events. Evidence for whole-plant cannabis and other comparisons, outcomes, and plant-based compounds was unavailable or insufficient to draw conclusions. Small sample sizes, lack of evidence for moderate and long-term use and other key outcomes, such as other adverse events and impact on use of opioids during treatment, indicate that more research is needed.
7
Chou, Roger, Azrah Y. Ahmed, Christina Bougatsos, et al. Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain: 2022 Update—Surveillance Report 2. Agency for Healthcare Research and Quality (AHRQ), 2023. http://dx.doi.org/10.23970/ahrqepccer250.2022updatesr2.
Full textAbstract:
Objectives. To update the evidence on benefits and harms of cannabinoids and similar plant-based compounds to treat chronic pain using a living systematic review approach. Data sources. Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Library, and SCOPUS® databases; reference lists of included studies; and submissions received after Federal Register request were searched to October 24, 2022. Review methods. Using dual review, we screened search results for randomized controlled trials (RCTs) and observational studies of patients with chronic pain evaluating cannabis, kratom, and similar compounds with any comparison group and at least 1 month of treatment or followup. Dual review was used to abstract study data, assess study-level risk of bias, and rate the strength of evidence (SOE). Prioritized outcomes included pain, overall function, and adverse events. We grouped studies that assessed tetrahydrocannabinol (THC) and/or cannabidiol (CBD) based on their THC to CBD ratio and categorized them as comparable THC to CBD ratio, high-THC to CBD ratio, and low-THC to CBD ratio. We also grouped studies by whether the product was a whole-plant product (cannabis), cannabinoids extracted or purified from a whole plant, or a synthetic product. We conducted meta-analyses using the profile likelihood random effects model and assessed between-study heterogeneity using Cochran’s Q statistic chi square test and the I2 statistic. Magnitude of benefit was categorized as no effect or small, moderate, and large effects. Results. From a total of 3,568 abstracts, 21 RCTs (N=1,905) and 9 observational studies (N=15,079) assessing different cannabinoids were included; none evaluated kratom. Studies were primarily short term, and 60 percent enrolled patients with neuropathic pain. Comparators were primarily placebo or usual care. The SOE was low unless otherwise noted. Compared with placebo, comparable THC to CBD ratio oral spray was associated with a small benefit in pain severity (7 RCTs, N=632, 0 to 10 scale, mean difference [MD] −0.54, 95% confidence interval [CI] −0.95 to −0.19, I2=39%; SOE: moderate) and overall function (6 RCTs, N=616, 0 to 10 scale, MD −0.42, 95% CI −0.73 to −0.16, I2=32%). There was no effect on study withdrawals due to adverse events. There was a large increased risk of dizziness and sedation, and a moderate increased risk of nausea (dizziness: 6 RCTs, N=866, 31.0% vs. 8.0%, relative risk [RR] 3.57, 95% CI 2.42 to 5.60, I2=0%; sedation: 6 RCTs, N=866, 8.0% vs. 1.2%, RR 5.04, 95% CI 2.10 to 11.89, I2=0%; and nausea: 6 RCTs, N=866, 13% vs. 7.5%, RR 1.79, 95% CI 1.19 to 2.77, I2=0%). Synthetic products with high-THC to CBD ratios were associated with a moderate improvement in pain severity, a moderate increase in sedation, and a large increase in nausea (pain: 6 RCTs, N=390, 0 to 10 scale, MD −1.15, 95% CI −1.99 to −0.54, I2=48%; sedation: 3 RCTs, N=335, 19% vs. 10%, RR 1.73, 95% CI 1.03 to 4.63, I2=28%; nausea: 2 RCTs, N=302, 12.3% vs. 6.1%, RR 2.19, 95% CI 0.77 to 5.39; I²=0%). We also found moderate SOE for a large increased risk of dizziness (2 RCTs, 32% vs. 11%, RR 2.74, 95% CI 1.47 to 6.86, I2=40%). Extracted whole-plant products with high-THC to CBD ratios (oral) were associated with a large increased risk of study withdrawal due to adverse events (1 RCT, 13.9% vs. 5.7%, RR 3.12, 95% CI 1.54 to 6.33) and dizziness (1 RCT, 62.2% vs. 7.5%, RR 8.34, 95% CI 4.53 to 15.34); outcomes assessing benefit were not reported or insufficient. We observed a moderate improvement in pain severity when combining all studies of high-THC to CBD ratio (8 RCTs, N=684, MD −1.25, 95% CI −2.09 to −0.71, I2=58%; SOE: moderate). Evidence (including observational studies) on whole-plant cannabis, topical or oral CBD, low-THC to CBD, other cannabinoids, comparisons with active products or between cannabis-related products, and impact on use of opioids was insufficient to draw conclusions. Other important harms (psychosis, cannabis use disorder, and cognitive effects) were not reported. Conclusions. Low to moderate strength evidence suggests small to moderate improvements in pain (mostly neuropathic), and moderate to large increases in common adverse events (dizziness, sedation, nausea) with high and comparable THC to CBD ratio extracted cannabinoids and synthetic products during short-term treatment (1 to 6 months); high-THC to CBD ratio products were also associated with increased risk of withdrawal due to adverse events. Evidence for whole-plant cannabis and other comparisons, outcomes, and plant-based compounds was unavailable or insufficient to draw conclusions. Small sample sizes, lack of evidence for moderate and long-term use and other key outcomes, such as other adverse events and impact on use of opioids during treatment, indicate that more research is needed.
8
McDonagh, Marian S., Jesse Wagner, Azrah Y. Ahmed, et al. Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain. Agency for Healthcare Research and Quality (AHRQ), 2021. http://dx.doi.org/10.23970/ahrqepccer250.
Full textAbstract:
Objectives. To evaluate the evidence on benefits and harms of cannabinoids and similar plant-based compounds to treat chronic pain. Data sources. Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Library, and SCOPUS® databases, reference lists of included studies, submissions received after Federal Register request were searched to July 2021. Review methods. Using dual review, we screened search results for randomized controlled trials (RCTs) and observational studies of patients with chronic pain evaluating cannabis, kratom, and similar compounds with any comparison group and at least 1 month of treatment or followup. Dual review was used to abstract study data, assess study-level risk of bias, and rate the strength of evidence. Prioritized outcomes included pain, overall function, and adverse events. We grouped studies that assessed tetrahydrocannabinol (THC) and/or cannabidiol (CBD) based on their THC to CBD ratio and categorized them as high-THC to CBD ratio, comparable THC to CBD ratio, and low-THC to CBD ratio. We also grouped studies by whether the product was a whole-plant product (cannabis), cannabinoids extracted or purified from a whole plant, or synthetic. We conducted meta-analyses using the profile likelihood random effects model and assessed between-study heterogeneity using Cochran’s Q statistic chi square and the I2 test for inconsistency. Magnitude of benefit was categorized into no effect or small, moderate, and large effects. Results. From 2,850 abstracts, 20 RCTs (N=1,776) and 7 observational studies (N=13,095) assessing different cannabinoids were included; none of kratom. Studies were primarily short term, and 75 percent enrolled patients with a variety of neuropathic pain. Comparators were primarily placebo or usual care. The strength of evidence (SOE) was low, unless otherwise noted. Compared with placebo, comparable THC to CBD ratio oral spray was associated with a small benefit in change in pain severity (7 RCTs, N=632, 0 to10 scale, mean difference [MD] −0.54, 95% confidence interval [CI] −0.95 to −0.19, I2=28%; SOE: moderate) and overall function (6 RCTs, N=616, 0 to 10 scale, MD −0.42, 95% CI −0.73 to −0.16, I2=24%). There was no effect on study withdrawals due to adverse events. There was a large increased risk of dizziness and sedation and a moderate increased risk of nausea (dizziness: 6 RCTs, N=866, 30% vs. 8%, relative risk [RR] 3.57, 95% CI 2.42 to 5.60, I2=0%; sedation: 6 RCTs, N=866, 22% vs. 16%, RR 5.04, 95% CI 2.10 to 11.89, I2=0%; and nausea: 6 RCTs, N=866, 13% vs. 7.5%, RR 1.79, 95% CI 1.20 to 2.78, I2=0%). Synthetic products with high-THC to CBD ratios were associated with a moderate improvement in pain severity, a moderate increase in sedation, and a large increase in nausea (pain: 6 RCTs, N=390 to 10 scale, MD −1.15, 95% CI −1.99 to −0.54, I2=39%; sedation: 3 RCTs, N=335, 19% vs. 10%, RR 1.73, 95% CI 1.03 to 4.63, I2=0%; nausea: 2 RCTs, N=302, 12% vs. 6%, RR 2.19, 95% CI 0.77 to 5.39; I²=0%). We found moderate SOE for a large increased risk of dizziness (2 RCTs, 32% vs. 11%, RR 2.74, 95% CI 1.47 to 6.86, I2=0%). Extracted whole-plant products with high-THC to CBD ratios (oral) were associated with a large increased risk of study withdrawal due to adverse events (1 RCT, 13.9% vs. 5.7%, RR 3.12, 95% CI 1.54 to 6.33) and dizziness (1 RCT, 62.2% vs. 7.5%, RR 8.34, 95% CI 4.53 to 15.34). We observed a moderate improvement in pain severity when combining all studies of high-THC to CBD ratio (8 RCTs, N=684, MD −1.25, 95% CI −2.09 to −0.71, I2=50%; SOE: moderate). Evidence on whole-plant cannabis, topical CBD, low-THC to CBD, other cannabinoids, comparisons with active products, and impact on use of opioids was insufficient to draw conclusions. Other important harms (psychosis, cannabis use disorder, and cognitive effects) were not reported. Conclusions. Low to moderate strength evidence suggests small to moderate improvements in pain (mostly neuropathic), and moderate to large increases in common adverse events (dizziness, sedation, nausea) and study withdrawal due to adverse events with high- and comparable THC to CBD ratio extracted cannabinoids and synthetic products in short-term treatment (1 to 6 months). Evidence for whole-plant cannabis, and other comparisons, outcomes, and PBCs were unavailable or insufficient to draw conclusions. Small sample sizes, lack of evidence for moderate and long-term use and other key outcomes, such as other adverse events and impact on use of opioids during treatment, indicate that more research is needed.
9
Chou, Roger, Azrah Y. Ahmed, Benjamin J. Morasco, et al. Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain: 2023 Update. Agency for Healthcare Research and Quality, 2023. http://dx.doi.org/10.23970/ahrqepccer250update2023.
Full textAbstract:
Objectives. To update the evidence on benefits and harms of cannabinoids and other plant-based compounds to treat sub-acute and chronic pain in adults and adolescents using a living systematic review approach. Data sources. Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Library, and SCOPUS® databases; and reference lists of included studies were searched to April 23, 2023. Review methods. An updated protocol with expanded inclusion criteria (addition of sub-acute [4 to 12 weeks’ duration] pain and adolescents) was posted on the PROSPERO registry. We grouped studies based on their THC to CBD ratio and by product type, i.e. whole-plant (extracted or purified), or synthetic. We conducted random effects meta-analyses and categorized magnitude of benefit (large, moderate, small, or no effect [less than small]). Results. Two new RCTs (n=115 and 15) and two new observational studies (N=2,071) were added for this annual update; no study addressed subacute pain or adolescents. One new RCT compared high and low THC to CBD ratio products versus placebo; the other new RCT evaluated was very small and had methodological limitations. Since the inception of this living review, from 5,228 total abstracts identified, 23 RCTs (N=2,035) and 10 observational studies (N=15,840) assessing different cannabinoids were included; no study evaluated kratom. Studies were primarily short term, and 58 percent enrolled patients with neuropathic pain. Comparators were primarily placebo or usual care. Strength of evidence was low, unless indicated otherwise. Compared with placebo, plant-extracted, comparable ratio THC to CBD oral spray was associated with a small decrease in pain severity (7 RCTs, N=632, 0 to 10 scale, mean difference [MD] −0.54, 95% confidence interval [CI] −0.95 to −0.19, I2=39%; SOE: moderate) and overall function (6 RCTs, N=616, 0 to 10 scale, MD −0.42, 95% CI −0.73 to −0.16, I2=32%; SOE: moderate) versus placebo. There was no effect on study withdrawals due to adverse events. There was a large increased risk of dizziness and sedation, and a moderate increased risk of nausea (dizziness: 6 RCTs, N=866, 31.0% vs. 8.0%, relative risk [RR] 3.57, 95% CI 2.42 to 5.60, I2=0%; sedation: 6 RCTs, N=866, 8.0% vs. 1.2%, RR 5.04, 95% CI 2.10 to 11.89, I2=0%; and nausea: 6 RCTs, N=866, 13% vs. 7.5%, RR 1.79, 95% CI 1.19 to 2.77, I2=0%). Synthetic high-THC to CBD ratio products were associated with a small improvement in pain severity, a moderate increase in sedation, and a large increase in risk of nausea following the addition of one new RCT (pain: 7 RCTs, N=448, 0 to 10 scale, MD −0.95, 95% CI −1.81 to −0.25, I2=60%; sedation: 4 RCTs, N=386, 19% vs. 12%, RR 1.60, 95% CI 1.01 to 2.95, I2=8%; nausea: 3 RCTs, N=353, 11.1% vs. 5.2%, RR 2.22, 95% CI 0.90 to 5.05; I²=0%). There was also moderate SOE for a large increased risk of dizziness (3 RCTs, N=353, 29% vs. 11%, RR 2.52, 95% CI 1.20 to 4.82, I2=41%). Extracted whole-plant high-THC to CBD ratio products (oral) were associated with a large increased risk of study withdrawal due to adverse events (1 RCT, viii 13.9% vs. 5.7%, RR 3.12, 95% CI 1.54 to 6.33) and dizziness (1 RCT, 62.2% vs. 7.5%, RR 8.34, 95% CI 4.53 to 15.34); outcomes assessing benefit were not reported or insufficient. Evidence (including observational studies) on whole-plant cannabis, topical or oral CBD, low-THC to CBD products (2 new RCTs), other cannabinoids, comparisons with active non-cannabis treatments or between cannabis-related products, and impact on use of opioids also remained insufficient. Evidence was not available on important harms such as psychosis, cannabis use disorder, and cognitive effects. Conclusions. Low to moderate strength evidence suggests small improvements in pain (mostly neuropathic), and moderate to large increases in common adverse events (dizziness, sedation, nausea) with high and comparable THC to CBD ratio extracted cannabinoids and synthetic products versus placebo during short-term treatment (1 to 6 months) in adults with chronic pain. Evidence for low-THC to CBD ratio products, whole-plant cannabis, and other comparisons, outcomes, and plant-based compounds was unavailable or insufficient to draw conclusions.
10
Davidson, Irit, Hsing-Jien Kung, and Richard L. Witter. Molecular Interactions between Herpes and Retroviruses in Dually Infected Chickens and Turkeys. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7575275.bard.
Full textAbstract:
Tumors in commercial poultry are caused mainly by infection with avian herpes and retroviruses, the herpesvirus Marek's disease virus (MDV) and the retroviruses, reticuloendotheliosis (REV), lymphoid leukosis, subgroups A-I and J (ALV and ALV-J) in chickens, or Iymphoprolipherative disease (LPDV) in turkeys. Infection with one virus aggravates the clinical outcome of birds that are already infected by another oncogenic virus. As these viruses do not interfere for infection, MDV and one or more retroviruses can infect the same flock, the same bird and the same cell. While infecting the same cell, herpes and retroviruses might interact in at least three ways: a) Integration of retrovirus genomes, or genomic fragments (mainly the LTR) into MDV;b) alteration of LTR-driven expression of retroviral genes by MDV immediate- early genes, and c) by herpesvirus induced cellular transcriptional factors. The first type of molecular interaction have been demonstrated to happen efficiently in vitro by Dr. Kung, in cases multiple infection of cell cultures with MDV and REV or MDV and ALV. Moreover, Dr. Witter showed that an in vitro-created recombinant, RM1, had altered in vitro replication and in vivo biological properties. A more comprehensive characterization of RM1 was carried out in the present project. We sought to highlight whether events of such integrations occur also in the bird, in vivo. For that, we had first to determine the prevalence of dually-infected individual birds in commercial flocks, as no systematic survey has been yet reported. Surprisingly, about 25% of the commercial flocks infected with avian oncogenic viruses had a multiple virus infection and 5% of the total samples ana lysed had multiple virus sequences. Then, we aimed to evaluate and characterize biologically and molecularly the resulting recombinants, if formed, and to analyse the factors that affect these events (virus strains, type and age of birds and time interval between the infection with both viruses). The perception of retrovirus insertions into herpesviruses in vivo is not banal, as the in vivo and in vitro systems differ in the viral-target cells, lymphocytes or fibroblasts, in the MDV-replicative type, transforming or productive, and the immune system presence. We realized that previous methods employed to study in vitro created recombinant viruses were not adequate for the study of samples taken directly from the bird. Therefore, the Hot Spot-combined PCR was developed based on the molecularly known RM1 virus. Also, the PFGE that was used for tissue cultured-MDV separation was inefficient for separating MDV from organs, but useful with feather tips as a source of bird original MDV. Much attention was dedicated now to feathers, because if a recombinant virus would be formed in vivo, its biological significance would be evident by horizontal dissemination through the feathers. Major findings were: a) not only in vitro, but also in vivo MDV and retrovirus co-infections lead to LTR integrations into MDV. That was shown by the detection of chimeric molecules. These appeared in low quantities and as quasispecies, thus interfering with sequence analysis of cloned gel-purified chimeric molecules. Mainly inserts were located in the repeat long MDV fragments. In field birds chimeric molecules were detected at a lower frequency (2.5%) than in experimentally infected birds (30-50%). These could be transmitted experimentally to another birds by inoculation with chimeric molecules containing blood. Several types of chimeric molecules were formed, and same types were detected in birds infected by a second round. To reproduce viral integrations, in vivo infection trials were done with field inoculate that contained both viruses, but the chimeric molecule yield was undetectable.