RESUMO
Disasters such as hurricanes, earthquakes and floods continue to have devastating socioeconomic impacts and endanger millions of lives. Shelters are safe zones that protect victims from possible damage, and evacuation routes are the paths from disaster zones toward shelter areas. To enable the timely evacuation of disaster zones, decisions regarding shelter location and routing assignment (i.e., traffic assignment) should be considered simultaneously. In this work, we propose a risk-averse stochastic programming model with a chance constraint that takes into account the uncertainty in the demand of disaster sites while minimizing the total evacuation time. The total evacuation time reflects the efficacy of emergency management from a system optimal (SO) perspective. A conditional value-at-risk (CVaR) is incorporated into the objective function to account for risk measures in the presence of uncertain post-disaster demand. We resolve the non-linear travel time function of traffic flow by employing a second-order cone programming (SOCP) approach and linearizing the non-linear chance constraints into a new mixed-integer linear programming (MILP) reformulation so that the problem can be directly solved by state-of-the-art optimization solvers. We illustrate the application of our model using two case studies. The first case study is used to demonstrate the difference between a risk-neutral model and our proposed model. An extensive computational study provides practical insight into the proposed modeling approach using another case study concerning the Black Saturday bushfire in Australia.
Assuntos
Planejamento em Desastres/organização & administração , Abrigo de Emergência/organização & administração , Desastres Naturais , Austrália , Condução de Veículo , Tempestades Ciclônicas , Terremotos , Inundações , Humanos , Fatores de Tempo , IncertezaRESUMO
Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.
Assuntos
Humanos , RNA não Traduzido/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , RNA Circular , Doenças do Sistema Nervoso Central/genéticaRESUMO
The Shiyang River Basin is an important ecological area of the Eastern Hexi Corridor, and is one of the most prominent areas of water conflict and ecological environment problems. An assessment of ecosystem quality in the Shiyang River Basin can provide a reference for ecological protection in arid inland basin. Based on the concept of ecosystem quality and the statistical yearbook, remotely sensed and land cover data, an evaluation index was established with consideration of three aspects of ecosystem (i.e., productivity, stability and bearing capacity). Kruskal-Wallis (Φ2) test and entropy method were applied to determine the weights of evaluation index. With the assistance of RS, GIS and SPSS software, a comprehensive evaluation and change analysis of ecosystem quality and corresponding index were conducted for various ecosystem types in the Shiyang River Basin in 2000, 2005, 2010 and 2015. Results showed that the average ecosystem quality of the Shiyang River Basin was 57.76, and presented an obvious decrease with a magnitude of 0.72 per year du-ring 2000-2015. The spatial pattern of ecosystem quality was that the upstream was better than the midstream, and the midstream was superior to the downstream. The mean values of production capacity, stability and carrying capacity of ecosystem were 67.52, 45.37, and 58.53, respectively. Production capacity and stability had increased slightly, while carrying capacity gradually decreased. Considering various ecosystem types, the highest quality was detected for forest ecosystem with average annual value of 78.12, and this ecosystem presented the lowest decreasing magnitude of 0.28 per year; for grassland, farmland and urban ecosystems, the average annual value was 62.45, 58.76 and 50.29, respectively; the quality of wetland ecosystem was the lowest, and suffered the largest decline with an average rate of 0.98 per year.
Assuntos
Conservação dos Recursos Naturais , Ecossistema , Sistemas de Informação Geográfica , China , Monitoramento Ambiental , RiosRESUMO
Objective To evaluate the value of transthoracic echocardionraphy(TTE)and angiographic appearance for measurement of the diameter of patent ductus arteriosus(PDA)in transcatheter interventions.Methods In 52 patients,the position,diameter and length of ductus arteriosus between the descending aorta and the pulmonary artery were observed and the narrowest diameter of PDA was measured by TTE.In angiographic appearance,pig catheter was selected to perform left lateral aortography and measure the narrowest diameter of PDA.Comparative studies were performed on the numbers measured by 2 methods.Results Aortography showed that 45 patients had funnel shape PDA and 5 patients had tubular shape PDA,while 1 patient had funnel plus tubular shape PDA and 1 patient had residual shunt after operation.TTE showed that 46 patients had funnel shape PDA,4 patients had tubular shape PDA and 1 patient had window shape PDA,1 patient had residual shunt after operation.The mean diameter of PDA measured by angiographic appearance was(3.72?2.51)mm,which was statistically lower than those by TTE(4.47?2.31)mm(t=5.17 P