scholarly journals Copula approach for simulated damages caused by landfalling US hurricanes

2021 ◽  
Vol 7 (1) ◽  
pp. 1-11
Author(s):  
Thomas Patrick Leahy
Keyword(s):  
External Validation ◽  
Rank Correlation ◽  
Potential Method ◽  
Small Data ◽  
Limited Data ◽  
Hurricane Wind ◽  
Copula Approach ◽  
Contour Plots ◽  
Frank Copula ◽  
Potential Damage

Abstract. Hurricanes are destructive forces of nature that have the ability to cause vast devastation both economically and socially. Estimating the potential damage caused by hurricanes aids local, state and federal governments as well as insurance and reinsurance companies to plan for future hurricanes. Direct damages caused by hurricanes are difficult to estimate. There are multiple factors that could contribute to the damages caused by a hurricane. Wind is typically considered the most important factor to account for when estimating potential damage. Aside from the complex physical processes, the difficultly in estimating hurricane damages is further compounded by limited data and a changing climate. Fitting models with limited data presents a series of challenges. These challenges include outliers that could form a large proportion of the data, overfitting, missing data and it becomes difficult to leave out a portion of the data for external validation. This study found a significant positive correlation using the Kendall rank correlation coefficient between hurricane damages, measured by the area of total destruction and the maximum landfalling wind speed (τ = 0.451). A copula-based approach was used to model their dependency. Both bivariate Archimedean and elliptical copulae families were assessed as potential models. A bivariate Frank copula with Weibull marginals was found to be the most appropriate fitting model based on a visual inspection of the contour plots of the fitted copulae. Simulation from the fitted copula was qualitatively similar to observation. This study demonstrated a potential method to overcome the limitation of small data facing models to estimate hurricane damages.

scholarly journals Surface Pressure a More Skillful Predictor of Normalized Hurricane Damage than Maximum Sustained Wind

2020 ◽  
Vol 101 (6) ◽  
pp. E830-E846 ◽  
Author(s):  
Philip J. Klotzbach ◽  
Michael M. Bell ◽  
Steven G. Bowen ◽  
Ethan J. Gibney ◽  
Kenneth R. Knapp ◽  
...  
Keyword(s):  
Storm Surge ◽  
Rank Correlation ◽  
Economic Damage ◽  
Measured Quantity ◽  
Sea Level Pressure ◽  
Hurricane Damage ◽  
Hurricane Wind ◽  
History Of ◽  
Potential Damage ◽  
Financial Impacts

Abstract Atlantic hurricane seasons have a long history of causing significant financial impacts, with Harvey, Irma, Maria, Florence, and Michael combining to incur more than 345 billion USD in direct economic damage during 2017–2018. While Michael’s damage was primarily wind and storm surge-driven, Florence’s and Harvey’s damage was predominantly rainfall and inland flood-driven. Several revised scales have been proposed to replace the Saffir–Simpson Hurricane Wind Scale (SSHWS), which currently only categorizes the hurricane wind threat, while not explicitly handling the totality of storm impacts including storm surge and rainfall. However, most of these newly-proposed scales are not easily calculated in real-time, nor can they be reliably calculated historically. In particular, they depend on storm wind radii, which remain very uncertain. Herein, we analyze the relationship between normalized historical damage caused by continental United States (CONUS) landfalling hurricanes from 1900–2018 with both maximum sustained wind speed (Vmax) and minimum sea level pressure (MSLP). We show that MSLP is a more skillful predictor of normalized damage than Vmax, with a significantly higher rank correlation between normalized damage and MSLP (rrank = 0.77) than between normalized damage and Vmax (rrank = 0.66) for all CONUS landfalling hurricanes. MSLP has served as a much better predictor of hurricane damage in recent years than Vmax, with large hurricanes such as Ike (2008) and Sandy (2012) causing much more damage than anticipated from their SSHWS ranking. MSLP is also a more accurately-measured quantity than is Vmax, making it an ideal quantity for evaluating a hurricane’s potential damage.

In vitro effectiveness of biapenem against IMP-producing Enterobacteriaceae

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Kazuyoshi Gotoh ◽  
Makoto Miyoshi ◽  
I Putu Bayu Mayura ◽  
Koji Iio ◽  
Osamu Matsushita ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Small Data ◽  
Limited Data ◽  
Data Set ◽  
Content Type ◽  
Link Type ◽  
Almost All ◽  
New Treatments ◽  
Time Kill

The options available for treating infections with carbapenemase-producing Enterobacteriaceae (CPE) are limited; with the increasing threat of these infections, new treatments are urgently needed. Biapenem (BIPM) is a carbapenem, and limited data confirming its in vitro killing effect against CPE are available. In this study, we examined the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of BIPM for 14 IMP-1-producing Enterobacteriaceae strains isolated from the Okayama region in Japan. The MICs against almost all the isolates were lower than 0.5 µg ml−1, indicating susceptibility to BIPM, while approximately half of the isolates were confirmed to be bacteriostatic to BIPM. However, initial killing to a 99.9 % reduction was observed in seven out of eight strains in a time–kill assay. Despite the small data set, we concluded that the in vitro efficacy of BIPM suggests that the drug could be a new therapeutic option against infection with IMP-producing CPE.

scholarly journals A signature predictive of early versus late recurrence after radiation (RT) for breast cancer that may inform the biology of early, aggressive recurrences.

2019 ◽  
Vol 5 (suppl) ◽  
pp. 112-112
Author(s):  
Corey Wayne Speers ◽  
S. Laura Chang ◽  
Benjamin Chandler ◽  
Andrea Pesch ◽  
Anna Michmerhuizen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cox Regression ◽  
External Validation ◽  
Rank Correlation ◽  
Local Therapy ◽  
Feature Reduction ◽  
Recurrence Time ◽  
P Value ◽  
Treatment Intensification

112 Background: Unmet clinical needs in breast cancer (BC) management include the identification of patients at high risk to fail locally despite standard local therapy and an understanding of the biology of these recurrences. We previously reported a radiation response signature and here extend those studies to identify a signature predictive of timing of recurrence after RT. Methods: 2 independent patient cohorts were used for training (119 pts) and validation (112 pts). All patients received RT after BCS and systemic therapy as appropriate. Spearman’s rank correlation to correlate gene expression to recurrence time was used for feature selection. Significant genes were used to train a linear model which was locked before validation. Cox regression was used for both UVA and MVA. Results: Spearman’s correlation identified 485 genes whose expression was significantly associated with recurrence time (+/-3 yrs). Feature reduction refined the list to 41 genes retained within the signature. In training, the correlation of score to recurrence time was 0.85, p-value < 1.3x10-31; AUC of 0.91. External validation in an independent BC validation set accurately identified patients with early vs. late recurrences (correlation= 0.75, p-value = 0.001, AUC = 0.92, sens.=0.75, spec.= 1.0, PPV = 1.0, NPV = 0.8). Unique associations of breast cancer intrinsic subtype to timing of local recurrence were found. In UVA and MVA the signature remained the most significant factor associated with recurrence. GSEA analysis of the 41 genes retained within the signature identified proliferation and EGFR concepts associated with early recurrences and luminal and ER-signaling pathways associated with late recurrences. Knockdown of genes associated with the early and late recurrences demonstrated novel effects on proliferation and clonogenic survival, respectively. Conclusions: We report a BC gene expression signatures that may be useful in identifying patients unlikely to respond to adjuvant RT and may be used to predict timing of recurrences, with implications for potential treatment intensification and duration of follow-up for women with breast cancer treated with RT.

Assortative sexual mixing patterns in male–female and male–male partnerships in Melbourne, Australia: implications for HIV and sexually transmissible infection transmission

Sexual Health ◽  
2016 ◽  
Vol 13 (5) ◽  
pp. 451 ◽  
Author(s):  
Eric P. F. Chow ◽  
Tim R. H. Read ◽  
Matthew G. Law ◽  
Marcus Y. Chen ◽  
Catriona S. Bradshaw ◽  
...  
Keyword(s):  
Condom Use ◽  
Health Centre ◽  
Rank Correlation ◽  
Risk Groups ◽  
Strong Positive Correlation ◽  
Limited Data ◽  
Spearman’S Rank Correlation ◽  
Mixing Patterns ◽  
Sexually Transmissible Infection ◽  
Transmissible Infection

Background: Assortative mixing patterns have become a new and important focus in HIV/sexually transmissible infection (STI) research in recent years. There are very limited data on sexual mixing patterns, particularly in an Australian population. Methods: Male–female and male–male partnerships attending the Melbourne Sexual Health Centre (MSHC) between 2011 and 2014 were included. Correlation of age between two individuals within a partnership was examined by using Spearman’s rank correlation. The Newman’s assortativity coefficient was used as an aggregate quantitative measurement of sexual mixing for number of partners and condom use. Results: 1165 male–female and 610 male–male partnerships were included in the analysis. There was a strong positive correlation of age in both male–female (rho = 0.709; P < 0.001) and male–male partnerships (rho = 0.553; P < 0.001). The assortative mixing pattern for number of partners was similar in male–female (r = 0.255; 95% CI: 0.221–0.289) and male–male partnerships (r = 0.264; 95% CI: 0.218–0.309). There was a stronger assortative mixing pattern for condom use in male–male (r = 0.517, 95% CI: 0.465–0.569) compared with male–female (r = 0.382; 95% CI: 0.353–0.412) partnerships. Conclusion: Male–female and male–male partnerships have a high assortativity mixing pattern for age, number of partners and condom use. The sexual mixing pattern is not purely assortative, and hence it may lead to increased HIV and STI transmission in certain risk groups.

scholarly journals External Validation of Prediction Models for Unilateral Primary Aldosteronism

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A287-A287
Author(s):  
Davis Sam ◽  
Gregory A Kline ◽  
Benny So ◽  
Janice L Pasieka ◽  
Adrian Harvey ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Prediction Models ◽  
Validation Cohort ◽  
Large Population ◽  
External Validation ◽  
Poor Performance ◽  
Small Data ◽  
Data Sets ◽  
Recommended Treatment ◽  
Unilateral Disease

Abstract Primary aldosteronism (PA) is the most common cause of remediable hypertension. Treatment is informed by establishing whether disease is unilateral (localized to one adrenal gland) or bilateral. Adrenalectomy is the guideline-recommended treatment of choice for unilateral PA. However, the currently recommended subtyping test, adrenal vein sampling (AVS), is often limited in accessibility. Thus, prediction models have been developed to diagnose unilateral PA and therefore bypass AVS. However, their generalizability remains unknown. In this retrospective study, we aimed to externally validate the performance of prediction models for unilateral PA in a large population of PA patients at a Canadian referral center who underwent AVS during 2006–2018. The presence of unilateral disease was indicated by a lateralization index of &gt;3 on AVS. We identified 6 clinical prediction models from the literature. The discrimination and calibration of each model were systematically evaluated. For the original models, the derivation cohorts were based out of Japan, France, Italy, and England, with mean age between 46–54 years and 43–56% being male. The derivation cohorts were generally small, with 4 of the 6 studies reporting less than 50 people with unilateral PA. Common variables reported to be predictive of unilateral PA included male sex, hypokalemia, elevated aldosterone-renin ratio, and the presence of a unilateral adrenal nodule on imaging. The validation cohort included 342 PA patients who underwent successful AVS (average age, 52.1 years; 58.8% male). Among them, 186 (54.4%) demonstrated unilateral disease, and the remaining 156 (45.6%) were considered to have bilateral disease. The baseline characteristics of the validation cohort were broadly similar to those of the derivation cohorts, except for potential differences in ethnicity. When applying the models to the validation cohort, subjects were excluded if any candidate variables were missing. All 6 models demonstrated poor discrimination in the validation set (C-statistics; range, 0.59–0.72), representing a marked decrease compared to the derivation sets where they were reported (range, 0.80–0.87). Assessment of calibration by comparing observed and predicted probabilities of the unilateral subtype revealed significant miscalibration. Calibration-in-the-large for every model was &gt;0 (range, 0.36–2.23), signifying systematic underprediction of unilateral PA. Calibration slopes were all &lt;1 (range, 0.35–0.85), indicating poor performance at the extremes of risk. These results suggest that the original models were optimistic due to overfitting in the derivation cohorts and therefore lack generalizability. This is primarily because these models were developed in small data sets. In conclusion, clinical assessment with prediction models for unilateral PA cannot be readily used to bypass AVS in the general PA population.

Abstract 116: Predicting Symptomatic Intracranial Hemorrhage After Mechanical Thrombectomy: The TAG Score

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mayra Montalvo ◽  
Eva Mitry ◽  
Andrew Chang ◽  
Katarina Dakay ◽  
Idrees Azher ◽  
...  
Keyword(s):  
Mechanical Thrombectomy ◽  
External Validation ◽  
Limited Data ◽  
Derivation Cohort ◽  
Test Strategies ◽  
Stroke Study ◽  
Unit Increase ◽  
Symptomatic Intracranial Hemorrhage ◽  
Comprehensive Stroke Center ◽  
Stroke Center

Background: There is limited data on predictors of sICH in patients who underwent mechanical thrombectomy. In this study, we aim to determine those predictors with external validation. Methods: We evaluated mechanical thrombectomy in a derivation cohort of patients at a comprehensive stroke center over a 30-month period. sICH was defined using the European Cooperative Acute Stroke Study III. We compared clinical and radiographic characteristics between patients with and without sICH to identify independent predictors of sICH with p<0.1. We then derived an sICH prediction score and validated it using the Blood Pressure After Endovascular Treatment (BEST) multicenter prospective registry. Results: We identified 578 patients with acute ischemic stroke who received thrombectomy, 19 had sICH (3.3%). Predictive factors of sICH were: Thrombolysis in cerebral ischemia score, Alberta stroke program early computed tomography score (ASPECTS), and Glucose level, and using these predictors, we derived the weighted TAG score which was associated with sICH in the derivation (OR per unit increase 1.98, 95% CI 1.48-2.66, AUC=0.79) and validation (OR per unit increase 1.48, 95% CI 1.22-1.79, AUC=0.69) cohorts. Conclusion: High TAG scores are associated with sICH in patients receiving mechanical thrombectomy. Larger studies are needed to validate this scoring system and test strategies to reduce sICH risk and make thrombectomy safer in patients with elevated TAG scores.

Effects of indiscriminate fisheries on a group of small data-poor species in Thailand

2017 ◽  
Vol 75 (2) ◽  
pp. 642-652 ◽  
Author(s):  
Lindsay Aylesworth ◽  
Ratanavaree Phoonsawat ◽  
Amanda C J Vincent
Keyword(s):  
International Trade ◽  
Marine Species ◽  
International Markets ◽  
Vulnerability Analysis ◽  
Small Scale ◽  
Small Data ◽  
Relative Pressure ◽  
Limited Data ◽  
Management Plans ◽  
Management Challenge

Abstract As catches of economically valuable target fishes decline, indiscriminate fisheries are on the rise, where commercial and small-scale fishers retain and sell an increasing number of marine species. Some of these catches are destined for international markets and subject to international trade regulations. Many of these species are considered “data-poor” in that there are limited data on their biology, ecology, and exploitation, which poses a serious management challenge for sustainable fisheries and trade. Our research explores the relative pressure exerted by such indiscriminate fisheries on a data-poor marine fish genus—seahorses (Hippocampus spp.)—whose considerable international trade is regulated globally. Our focus is Thailand, a dominant fishing nation and the world‘s largest exporter of seahorses, where we gathered data by interviewing commercial and small-scale fishers and through port sampling of landed catch. We estimate that annual catches were more than threefold larger than previously documented, approximating 29 million individuals from all gears. Three fishing gears–two commercial (otter and pair trawl) and one small-scale (gillnet)–caught the most individuals. Results from port sampling and our vulnerability analysis confirmed that H. kelloggi, H. kuda, and H. trimaculatus were the three species (of seven found in Thai waters) most susceptible to fishing. Small-scale gillnets captured the majority of specimens under length at maturity, largely due to catches of juvenile H. kuda and H. trimaculatus. This research indicates a role for vulnerability analysis to initiate precautionary management plans while more extensive studies can be conducted.

scholarly journals Probabilistic analysis of coincident sums of precipitation at two measurement stations. Introduction to the method and an example

2018 ◽  
Vol 23 ◽  
pp. 00002
Author(s):  
Gabriela Biel
Keyword(s):  
Rank Correlation ◽  
Random Variable ◽  
Analysis Data ◽  
Botanical Garden ◽  
Copula Function ◽  
Rain Gauge ◽  
Two Dimensional ◽  
Copula Functions ◽  
Frank Copula ◽  
Definition Of

This article proposes the use of copula (copula function) for the purpose of two-dimensional analysis of the sums of precipitation as measured with a Hellman rain-gauge. The sums of precipitation are characterized by a two-dimensional random variable: the sum of uninterrupted sequence of rainfalls which were measured in Jelcz-Laskowice and the corresponding (coincident) sum of precipitation at the Botanical Garden in Wrocław. Several problems occur from the very start: debonding from time and lack of precipitation on one of stations. For the purpose of greater precision and correction it should be stated that in order to apply the two-dimensional copula functions we will use a random vector determining the sum of uninterrupted sequences of rainfalls at two simultaneous stations. In that way, this will not be a characteristics of the phenomenon, but rather the definition of two-dimensional random variable under analysis. Data for analysis has been derived from observational logs of the Institute of Meteorology and Water Management, branch in Wrocław. The results obtained in years 1980-2014 were subject to analysis. The aim of the work was to find the best two-dimensional probability distribution of a random variable (OpadJelcz, OpadOgród). The following were analysed from among the known copulas: the Archimedean copulas (the Gumbel copula, the Frank copula and the Clayton copula) and the Gaussian elliptical copula. The study of fitting of copulas to observed variables was carried out using the Spearmann's rank correlation coefficient and the best fitting was obtained for the Frank's copula.

scholarly journals External validation of the PRECISE-DAPT score in a large nationwide population of myocardial infarction patients: a SWEDEHEART study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Wester ◽  
M.A Mohammad ◽  
D Erlinge ◽  
S Koul
Keyword(s):  
Myocardial Infarction ◽  
Antiplatelet Therapy ◽  
Clinical Decision Making ◽  
Dual Antiplatelet Therapy ◽  
External Validation ◽  
Coronary Intervention ◽  
Bleeding Complications ◽  
Individual Risk ◽  
Small Data ◽  
Funding Source

Abstract Background/Introduction Dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with stent placement in myocardial infarction (MI) patients has improved ischemic outcomes but increased the risk of bleeding. The PRECISE-DAPT (Predicting bleeding complications in patients undergoing stent implantation and subsequent dual antiplatelet therapy) score has been implemented in recent guidelines to tailor the duration of DAPT based on each patient's individual risk profile. However, to date it has only been externally validated on small data samples or exclusively for subgroups of PCI treated MI patients. Purpose To assess the performance of the PRECISE-DAPT score in a nationwide cohort of MI patients undergoing PCI with subsequent DAPT. This will be the world's largest validation of the PRECISE-DAPT score in approximately 20.000 unique real-world MI patients. Methods Data from the Swedish Websystem for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry on MI patients treated with DAPT after PCI between 2008 and 2016 in Sweden were obtained and merged with the Swedish Patient Registry as well as the Prescribed Drugs Registry that holds data from all Swedish pharmacies. The ability of PRECISE-DAPT to predict bleeding and ischemic outcomes in relation to DAPT duration was determined. Results Results are to be announced. Conclusions Whether the PRECISE-DAPT score can be validated or not in a large nationwide cohort of MI patients in relation to DAPT duration, has the potential to impact current DAPT guidelines and clinical decision making in everyday practice. Further results and conclusions are to be announced. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Märta Winkler's research foundation and Thorsten Westerström's research foundation

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