scholarly journals Nowcasting Avalanches as Earthquakes and the Predictability of Strong Avalanches in the Olami-Feder-Christensen Model

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1228
Author(s):  
Jennifer Perez-Oregon ◽  
Fernando Angulo-Brown ◽  
Nicholas Vassiliou Sarlis
Keyword(s):  
Seismic Risk ◽  
Prediction Method ◽  
The State ◽  
Receiver Operating Characteristics ◽  
Operating Characteristics ◽  
Natural Time ◽  
Earthquake Model ◽  
Receiver Operating

Nowcasting earthquakes, suggested recently as a method to estimate the state of a fault and hence the seismic risk, is based on the concept of natural time. Here, we generalize nowcasting to a prediction method the merits of which are evaluated by means of the receiver operating characteristics. This new prediction method is applied to a simple (toy) model for the waiting (natural) time of the stronger earthquakes, real seismicity, and the Olami-Feder-Christensen earthquake model with interesting results revealing acceptable to excellent or even outstanding performance.

Kriteriumsbezogene Cut-Off-Werte für Tätigkeitsspielraum und Arbeitsintensität

Diagnostica ◽  
2019 ◽  
Vol 65 (3) ◽  
pp. 179-190 ◽  
Author(s):  
Vincent Mustapha ◽  
Renate Rau
Keyword(s):  
Receiver Operating Characteristics ◽  
Operating Characteristics ◽  
Receiver Operating

Zusammenfassung. Cut-Off-Werte ermöglichen eine ökonomische, binäre Beurteilung von Summenscores. Für Beanspruchungsfragebögen, die personenbezogene Merkmale erfragen, sind Cut-Off-Werte häufig vorhanden und in der klinischen Diagnostik unerlässlich. Für die Bewertung von Arbeitsmerkmalen sind Cut-Off-Werte ebenfalls wünschenswert. Bislang fehlen sie jedoch für die Beurteilung von Arbeitsmerkmalen wie Arbeitsintensität und Tätigkeitsspielraum. Zwischen 2006 und 2016 wurden daher in verschiedenen Branchen 801 objektive Arbeitsplatzanalysen durchgeführt, welche eine Unterteilung in gut und schlecht gestalteten Tätigkeitsspielraum sowie gut und schlecht gestaltete Arbeitsintensität nach DIN EN ISO 6385 (2016) ermöglichen. Anhand dieser Unterteilung wurden mit der Receiver-Operating-Characteristics-Analyse Cut-Off-Werte für den subjektiv-bedingungsbezogen Fragebogen zum Erleben von Arbeitsintensität und Tätigkeitsspielraum (FIT; Richter et al., 2000 ) ermittelt. Für den Tätigkeitsspielraum weisen Summenscores ≤ 22 und für die Arbeitsintensität Summenscores ≥ 15 auf eine schlechte Gestaltung des jeweiligen Arbeitsmerkmals hin. Anhand einer weiteren Stichprobe von 1 076 Arbeitenden konnte gezeigt werden, dass Arbeitende mit schlecht gestaltetem Tätigkeitspielraum vital erschöpfter sowie weniger engagiert sind und Arbeitende mit schlecht gestalteter Arbeitsintensität eine höhere Erholungsunfähigkeit sowie vitale Erschöpfung aufweisen.

scholarly journals Arterial Digital Pulse Photoplethysmography in Patients with Suspected Thoracic Outlet Syndrome: A Study of the “Ca+Pra” Maneuver

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1128
Author(s):  
Jeanne Hersant ◽  
Pierre Ramondou ◽  
Francine Thouveny ◽  
Mickael Daligault ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Thoracic Outlet Syndrome ◽  
Pulse Amplitude ◽  
Receiver Operating Characteristics ◽  
Upper Limbs ◽  
Operating Characteristics ◽  
Digital Pulse ◽  
Arterial Inflow ◽  
Receiver Operating

The level of pulse amplitude (PA) change in arterial digital pulse plethysmography (A-PPG) that should be used to diagnose thoracic outlet syndrome (TOS) is debated. We hypothesized that a modification of the Roos test (by moving the arms forward, mimicking a prayer position (“Pra”)) releasing an eventual compression that occurs in the surrender/candlestick position (“Ca”) would facilitate interpretation of A-PPG results. In 52 subjects, we determined the optimal PA change from rest to predict compression at imaging (ultrasonography +/− angiography) with receiver operating characteristics (ROC). “Pra”-PA was set as 100%, and PA was expressed in normalized amplitude (NA) units. Imaging found arterial compression in 23 upper limbs. The area under ROC was 0.765 ± 0.065 (p < 0.0001), resulting in a 91.4% sensitivity and a 60.9% specificity for an increase of fewer than 3 NA from rest during “Ca”, while results were 17.4% and 98.8%, respectively, for the 75% PA decrease previously proposed in the literature. A-PPG during a “Ca+Pra” test provides demonstrable proof of inflow impairment and increases the sensitivity of A-PPG for the detection of arterial compression as determined by imaging. The absence of an increase in PA during the “Ca” phase of the “Ca+Pra” maneuver should be considered indicative of arterial inflow impairment.

scholarly journals Indicadores antropométricos de sobrepeso e obesidade como preditores de alterações lipídicas em adolescentes

2011 ◽  
Vol 29 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Carmem Cristina Beck ◽  
Adair da Silva Lopes ◽  
Francisco José G. Pitanga
Keyword(s):  
Receiver Operating Characteristics ◽  
Operating Characteristics ◽  
Receiver Operating

OBJETIVO: Identificar o poder preditivo dos indicadores antropométricos de sobrepeso e obesidade para alterações lipídicas em adolescentes. MÉTODOS: Estudo transversal envolvendo 660 adolescentes de 14 a 19 anos (317 rapazes; 343 moças). Foram considerados os seguintes indicadores antropométricos: índice de massa corpórea (IMC), circunferência da cintura, razão cintura/estatura e índice de conicidade. As alterações lipídicas foram caracterizadas pelo colesterol total (CT) superior a 170mg/dL e lipoproteínas de alta densidade (HDL-C) inferiores a 45mg/dL. Para identificar os preditores das alterações lipídicas, adotou-se a análise das curvas Receiver Operating Characteristics (ROC). Foram calculados os pontos de corte com suas respectivas sensibilidades e especificidades e, posteriormente, as razões de prevalência entre os indicadores antropométricos e os desfechos investigados. RESULTADOS: As áreas sob as curvas ROC (intervalo de confiança de 95%) para CT elevado nos rapazes e respectivos pontos de corte foram: IMC de 0,74 (0,65-0,83) e 21,7kg/m²; circunferência de cintura de 0,73 (0,65-0,82) e 74cm; razão cintura/estatura de 0,72 (0,63-0,81) e 0,4; índice de conicidade de 0,60 (0,50-0,69) e 1,1. Para a predição dos baixos níveis de HDL-C, as áreas da curva ROC e os pontos de corte foram: IMC dos rapazes de 0,58 (0,52-0,64) e 20,7kg/m²; para as moças de 0,61 (0,53-0,69) e 20,8kg/m²; circunferência de cintura, rapazes com 0,57 (0,50-0,63) e 73,3cm, moças com 0,63 (0,55-0,72) e 71,5cm; razão cintura/estatura (C/Est), rapazes de 0,58 (0,52-0,65) e C/Est de 0,4, moças de 0,62 (0,54-0,70) e C/Est de 0,4; índice de conicidade, moças de 0,60 (0,51-0,68) e 1,1. CONCLUSÕES: Os indicadores antropométricos foram bons preditores de CT elevado nos rapazes e razoáveis para os baixos níveis de HDL-C para rapazes e moças.

scholarly journals Combined Omic Analyzes of Cerebral Thrombi: A New Molecular Approach to Identify Cardioembolic Stroke Origin

Stroke ◽  
2021 ◽  
Author(s):  
Laurent Suissa ◽  
Jean-Marie Guigonis ◽  
Fanny Graslin ◽  
Emmanuelle Robinet-Borgomano ◽  
Yves Chau ◽  
...  
Keyword(s):  
Stroke Prevention ◽  
Small Vessel Disease ◽  
Cardioembolic Stroke ◽  
Receiver Operating Characteristics ◽  
Secondary Stroke Prevention ◽  
Molecular Approach ◽  
Operating Characteristics ◽  
Cardiac Pathology ◽  
Molecular Features ◽  
Receiver Operating

Background and Purpose: The diagnosis of cardioembolic stroke can be challenging for patient management in secondary stroke prevention, particularly in the case of covert paroxysmal atrial fibrillation. The molecular composition of a cerebral thrombus is related to its origin. Therefore, proteomic and metabolomic analyses of the retrieved thrombotic material should allow the identification of biomarkers or signatures to improve the etiological diagnosis of stroke. Methods: In this pilot study, the proteome and metabolome of cerebral thrombi from atherothrombotic and cardioembolic stroke patients were studied according to ASCOD phenotyping (A: atherosclerosis; S: small-vessel disease; C: cardiac pathology; O: other causes; D: dissection), with the highest causality grade, from the ThrombiOMIC cohort (consecutive patients with stroke recanalized by mechanical thrombectomy in an acute phase). Proteomic and metabolomic results were used separately or combined, and the obtained omic signatures were compared with classical cardioembolic stroke predictors using pairwise comparisons of the area under receiver operating characteristics. Results: Among 59 patients of the ThrombiOMIC cohort, 34 patients with stroke showed a cardioembolic phenotype and 7 had an atherothrombotic phenotype. Two thousand four hundred fifty-six proteins and 5019 molecular features of the cerebral thrombi were identified using untargeted proteomic and metabolomic approaches, respectively. Area under receiver operating characteristics to predict the cardioembolic origin of stroke were calculated using the proteomic results (0.945 [95% CI, 0.871–1]), the metabolomic results (0.836 [95% CI, 0.714–0.958]), and combined signatures (0.996 [95% CI, 0.984–1]). The diagnostic performance of the combined signatures was significantly higher than that of classical predictors such as the plasmatic BNP (B-type natriuretic peptide) level (area under receiver operating characteristics, 0.803 [95% CI, 0.629–0.976]). Conclusions: The combined proteomic and metabolomic analyses of retrieved cerebral thrombi is a very promising molecular approach to predict the cardioembolic cause of stroke and to improve secondary stroke prevention strategies.

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