Minimization of a class of rare event probabilities and buffered probabilities of exceedance

2021 ◽  
Author(s):  
Amarjit Budhiraja ◽  
Shu Lu ◽  
Yang Yu ◽  
Quoc Tran-Dinh
Keyword(s):  
Rare Event

Proactivity after a rare event: Examining the role of empathy and attributions

2011 ◽  
Author(s):  
Shu-cheng Steve Chi ◽  
Shu-chen Chen ◽  
Ray Friedman
Keyword(s):  
Rare Event

Framework for rare event detection using Artificial Neural Network based context free grammar

2020 ◽  
Vol 39 (6) ◽  
pp. 8463-8475
Author(s):  
Palanivel Srinivasan ◽  
Manivannan Doraipandian
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Event Detection ◽  
Performance Metrics ◽  
Rare Events ◽  
Rare Event ◽  
Video Stream ◽  
Context Free Grammar ◽  
Artificial Neural ◽  
Context Free

Rare event detections are performed using spatial domain and frequency domain-based procedures. Omnipresent surveillance camera footages are increasing exponentially due course the time. Monitoring all the events manually is an insignificant and more time-consuming process. Therefore, an automated rare event detection contrivance is required to make this process manageable. In this work, a Context-Free Grammar (CFG) is developed for detecting rare events from a video stream and Artificial Neural Network (ANN) is used to train CFG. A set of dedicated algorithms are used to perform frame split process, edge detection, background subtraction and convert the processed data into CFG. The developed CFG is converted into nodes and edges to form a graph. The graph is given to the input layer of an ANN to classify normal and rare event classes. Graph derived from CFG using input video stream is used to train ANN Further the performance of developed Artificial Neural Network Based Context-Free Grammar – Rare Event Detection (ACFG-RED) is compared with other existing techniques and performance metrics such as accuracy, precision, sensitivity, recall, average processing time and average processing power are used for performance estimation and analyzed. Better performance metrics values have been observed for the ANN-CFG model compared with other techniques. The developed model will provide a better solution in detecting rare events using video streams.

Rare-event statistics and modular invariance

2017 ◽  
Vol 188 (01) ◽  
pp. 106-112 ◽  
Author(s):  
S.K. Nechaev ◽  
K. Polovnikov
Keyword(s):  
Rare Event ◽  
Modular Invariance

Giant Solitary Gastric Peutz-Jeghers Polyp Mimicking a Malignant Gastric Tumor: the Largest Described in Literature

2014 ◽  
Vol 23 (3) ◽  
pp. 321-324 ◽  
Author(s):  
Sorinel Lunca ◽  
Vlad Porumb ◽  
Natalia Velenciuc ◽  
Dan Ferariu ◽  
Gabriel Dimofte
Keyword(s):  
Upper Gastrointestinal Bleeding ◽  
Rare Event ◽  
Gastric Tumor ◽  
Node Metastasis ◽  
Mucocutaneous Pigmentation ◽  
History Of ◽  
Peutz Jeghers Syndrome ◽  
Upper Gastrointestinal ◽  
Gastric Malignancy ◽  
Polypoid Tumor

A solitary Peutz-Jeghers polyp is defined as a unique polyp occurring without associated mucocutaneous pigmentation or a family history of Peutz-Jeghers syndrome. Gastric solitary localization is a rare event, with only eight reported cases to date. We report herein the case of a 43-year old woman who presented with upper gastrointestinal bleeding, severe anemia, weight loss and asthenia. Endoscopy revealed a giant polypoid tumor with signs of neoplastic invasion of the cardia, with pathological aspect suggesting a Peutz-Jeghers hamartomatous polyp. Computed tomography suggested a malignant gastric tumor and a total gastrectomy was performed. The pathological specimen showed a giant 150/70/50 mm polypoid tumor and immunochemistry established the final diagnostic of a Peutz-Jegers type polyp. This is the largest solitary Peutz-Jeghers gastric polyp reported until now, and the second one mimicking a gastric malignancy with lymph node metastasis.

Rare event simulation

2017 ◽  
Author(s):  
Michael P. Allen ◽  
Dominic J. Tildesley
Keyword(s):  
Rare Event ◽  
Path Sampling ◽  
Rapid Progress ◽  
Computationally Efficient ◽  
Transition Path ◽  
Transition Path Sampling ◽  
Event Simulation ◽  
Reaction Coordinates ◽  
Simulation Techniques ◽  
Transition Interface

The development of techniques to simulate infrequent events has been an area of rapid progress in recent years. In this chapter, we shall discuss some of the simulation techniques developed to study the dynamics of rare events. A basic summary of the statistical mechanics of barrier crossing is followed by a discussion of approaches based on the identification of reaction coordinates, and those which seek to avoid prior assumptions about the transition path. The demanding technique of transition path sampling is introduced and forward flux sampling and transition interface sampling are considered as rigorous but computationally efficient approaches.

scholarly journals SARS-CoV-2 Persistent Viral Shedding in the Context of Hydroxychloroquine-Azithromycin Treatment

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Michel Drancourt ◽  
Sébastien Cortaredona ◽  
Cléa Melenotte ◽  
Sophie Amrane ◽  
Carole Eldin ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Elderly Patients ◽  
Rare Event ◽  
Viral Shedding ◽  
Qrt Pcr ◽  
Viral Culture ◽  
D Dimer

SARS-CoV-2 nasopharyngeal shedding contributes to the spread of the COVID-19 epidemic. Among 3271 COVID-19 patients treated at the Hospital University Institute Méditerranée Infection, Marseille, France from 3 March to 27 April 2020, tested at least twice by qRT-PCR, the median SARS-CoV-2 nasopharyngeal shedding duration was 6 days (range 2–54 days). Compared with short shedders (qRT-PCR positivity < 10 days), 34 (1.04%) persistent shedders (qRT-PCR positivity ≥ 17 days; mean ± SD: 23.3 ± 3.8 days) were significantly older, with associated comorbidities, exhibiting lymphopenia, eosinopenia, increased D-dimer and increased troponin (p < 0.05), and were hospitalized in intensive care unit in 17.7% vs. 1.1% of cases (p < 0.0001). Viral culture was positive in six persistent shedders after day 10, including in one patient after day 17, and no viral co-pathogen was detected in 33 tested patients. Persistent shedders received azithromycin plus hydroxychloroquine ≥ 3 days in 26/34 (76.5%) patients, a figure significantly lower than in short shedders (86.6%) (p = 0.042). Accordingly, mortality was 14.7% vs. 0.5% (p < 0.0001). Persistent shedding was significantly associated with persistent dyspnea and anosmia/ageusia (p < 0.05). In the context of COVID-19 treatment, including treatment with azithromycin plus hydroxychloroquine, the persistence of SARS-CoV-2 nasopharyngeal shedding was a rare event, most frequently encountered in elderly patients with comorbidities and lacking azithromycin plus hydroxychloroquine treatment.

scholarly journals Spatial distance between sites of sampling associated with genetic variation among Neospora caninum in aborted bovine foetuses from northern Italy

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Luca Villa ◽  
Pavlo Maksimov ◽  
Christine Luttermann ◽  
Mareen Tuschy ◽  
Alessia L. Gazzonis ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Neospora Caninum ◽  
Geographic Distance ◽  
Rare Event ◽  
Northern Italy ◽  
Spatial Distance ◽  
Italian Regions ◽  
Bovine Abortion

Abstract Background Neospora caninum, a coccidian protozoan, represents an important cause of bovine abortion. Available N. caninum strains show considerable variation in vitro and in vivo, including different virulence in cattle. To which extent sexual recombination, which is possible in the intestines of domestic dogs and closely related carnivores as definitive hosts, contributes to this variation is not clear yet. Methods Aborted bovine foetuses were collected between 2015 and early 2019 from Italian Holstein Friesian dairy herds suffering from reproductive problems. A total of 198 samples were collected from 165 intensive farms located in Lombardy, northern Italy. N. caninum samples were subjected to multilocus-microsatellite genotyping using ten previously established microsatellite markers. In addition to our own data, those from a recent study providing data on five markers from other northern Italian regions were included and analysed. Results Of the 55 samples finally subjected to genotyping, 35 were typed at all or 9 out of 10 loci and their individual multilocus-microsatellite genotype (MLMG) determined. Linear regression revealed a statistically significant association between the spatial distance of the sampling sites with the genetic distance of N. caninum MLMGs (P < 0.001). Including data from this and a previous North Italian study into eBURST analysis revealed that several of N. caninum MLMGs from northern Italy separate into four groups; most of the samples from Lombardy clustered in one of these groups. Principle component analysis revealed similar clusters and confirmed MLMG groups identified by eBURST. Variations observed between MLMGs were not equally distributed over all loci, but predominantly observed in MS7, MS6A, or MS10. Conclusions Our findings confirm the concept of local N. caninum subpopulations. The geographic distance of sampling was associated with the genetic distance as determined by microsatellite typing. Results suggest that multi-parental recombination in N. caninum is a rare event, but does not exclude uniparental mating. More comprehensive studies on microsatellites in N. caninum and related species like Toxoplasma gondii should be undertaken, not only to improve genotyping capabilities, but also to understand possible functions of these regions in the genomes of these parasites.

scholarly journals Analysis and outcomes of wrong site thyroid surgery

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gianlorenzo Dionigi ◽  
Marco Raffaelli ◽  
Rocco Bellantone ◽  
Carmela De Crea ◽  
Carlo Enrico Ambrosini ◽  
...  
Keyword(s):  
Thyroid Surgery ◽  
Rare Event ◽  
Lymph Node Excision ◽  
Legal Action ◽  
Preventive Strategies ◽  
Case Presentation ◽  
Wrong Site Surgery ◽  
Wrong Side ◽  
Low Volume ◽  
Wrong Site

Abstract Background In thyroid surgery, wrong-site surgery (WSS) is considered a rare event and seldom reported in the literature. Case presentation This report presents 5 WSS cases following thyroid surgery in a 20-year period. We stratified the subtypes of WSS in wrong target, wrong side, wrong procedure and wrong patient. Only planned and elective thyroid surgeries present WSS cases. The interventions were performed in low-volume hospitals, and subsequently, the patients were referred to our centres. Four cases of wrong-target procedures (thymectomies [n = 3] and lymph node excision [n = 1] performed instead of thyroidectomies) and one case of wrong-side procedure were observed in this study. Two wrong target cases resulting additionally in wrong procedure were noted. Wrong patient cases were not detected in the review. Patients experienced benign, malignant, or suspicious pathology and underwent traditional surgery (no endoscopic or robotic surgery). 40% of WSS led to legal action against the surgeon or a monetary settlement. Conclusion WSS is also observed in thyroid surgery. Considering that reports regarding the serious complications of WSS are not yet available, these complications should be discussed with the surgical community. Etiologic causes, outcomes, preventive strategies of WSS and expert opinion are presented.

scholarly journals Moment-Preserving and Mesh-Adaptive Reweighting Method for Rare-Event Sampling in Monte-Carlo Algorithms

2021 ◽  
pp. 108041
Author(s):  
C.U. Schuster ◽  
T. Johnson ◽  
G. Papp ◽  
R. Bilato ◽  
S. Sipilä ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Rare Event ◽  
Monte Carlo Algorithms
Sign in / Sign up

Export Citation Format

Share Document