Driver perception reaction time under the emergency evacuation situation

The way of scenario simulation is used to create a driving environment in the emergency evacuation and the questionnaire investigation. The Miriam ECG are used to verify the validity of the driving environment in the emergency evacuation from subjective and objective aspects. Based on the SimWorld driving simulator, the research is conducted on three kinds of Perception Reaction Time (PRT) under both normal situation and the emergency evacuation situation: the PRT under the sudden situation, the PRT during acceleration and the PRT during deceleration.     

The Onset of Health Problems and the Propensity of Workers to Change Employers and Occupations

Although many studies have investigated how poor health affects hours of work and labor force participation, few have examined the extent to which individuals adapt in order to remain in the labor market. Individuals experiencing health problems may move to different types of work in order to remain in the labor force or to reduce the negative labor market consequences of illness. This paper investigates the movement between employers, and among occupation categories when changing employers, using data from the Health and Retirement Study (HRS). One advantage of the HRS is that its questions on life‐cycle employment and health patterns permit a long‐term perspective on job mobility that is unavailable in most other datasets. Workers with health problems are more likely than healthy workers to remain with their current employer than to switch employers. But among those who switch employers, those with health problems are more likely to change broad occupational categories than are healthy workers. While many individuals remain with the same employer after the onset of health problems, many do switch employers and occupations, even in the presence of ADA legislation.     

The Impact of Migration on Social Capital: Do Migrants Take Their Bowling Balls with Them?

Questions surrounding the impact of population migration on social capital is the focus of this study. Putnam observed that “for people as for plants, frequent repotting disrupts root systems. It takes time for a mobile individual to put down new roots.” However, because of a trending decrease in mobility over time, Putnam rules out migration as an explanation for the long‐term decline in social capital that was the subject of his widely read 1995 book Bowling Alone: America's Declining Social Capital. This study undertakes an empirical examination of the impact of migration on county‐level social capital, which in tribute to Putnam one might view as an attempt to answer the question—do migrants take their bowling balls with them when they move? The potential for county‐level migration of population to impact social capital levels at particular locations in space arises from the conventional argument that social capital promotes trust and cooperation among agents. This trust increases socially efficient collective action but requires investment in relationships and commitment of scarce resources to build social capital. It seems plausible that migration of population might have a negative impact on the stock of social capital by interfering with trust and cooperation among agents. However, it is also possible that migrants may take their social capital with them to new places of residence. In other words, the propensity to join social and civic organizations might reflect inherent traits of individuals who are willing to make commitments of their resources to building social capital in any community where they reside.     

Analysis of Yangtze River Water as a Potential Source for Developing a Water Source Heat Pump in Chongqing

Characteristics of smoke flow and fire spread in a patio space of a high-rise building were studied to investigate their influences on fire compartment and safety evacuation. Fire development model was established and fire scenarios were designed to simulate fire and smoke spread by CFD software numerically based on concepts of fire performance-based design in a high-rise building with double patio space, whose height are 74. 65 m and 55. 95 m, respectively. Simulation results show that in all fire scenarios, performance targets for safety evacuation for people in each floor was satisfied, if smoke was extracted naturally using the patio space. Hang walls mounted in corridors around the patio space prevent smoke flowing out smoothly, shorten the coming of the risk time and increase fire danger. Using chimney effect, it is preferred to adopt natural smoke exhaust method in a high rise building with patio space.     

Numerical Simulation for Fire Smoke Flow in a High-rise Building with Patio Space

Characteristics of smoke flow and fire spread in a patio space of a high-rise building were studied to investigate their influences on fire compartment and safety evacuation.Fire development model was established and fire scenarios were designed to simulate fire and smoke spread by CFD software numerically based on concepts of fire performance-based design in a high-rise building with double patio space,whose height are 74.65 m and 55.95 m,respectively.Simulation results show that in all fire scenarios,performance targets for safety evacuation for people in each floor was satisfied,if smoke was extracted naturally using the patio space.Hang walls mounted in corridors around the patio space prevent smoke flowing out smoothly,shorten the coming of the risk time and increase fire danger.Using chimney effect,it is preferred to adopt natural smoke exhaust method in a high-rise building with patio space.     

Analysis of Fire Smoke Movement with Different Air Velocity at the Stair head to the Hall of a Metro Station

When a fire happens at the subway platform, the downward ventilation at the staircase which connects the hall and platform can prevent smoke spreading into the hall and provides guiding air for evacuation people. To investigate the influence of the ventilation rate on the smoke movement, the air velocity at the staircase was measured under three ventilation modes. Numerical model was established to simulate the real fire scenario. It is shown that the downward air velocity under fire is greater than that without fire, and the traditional design procedure without considering complex factors interaction in real fire scenario should be improved; when fire is near the staircase, smoke easily spills from the smoke screen to the concourse. And smoke concentration of concourse is even higher than that of platform because the hall is under air supply mode; when the fire locates at the public area of the platform, turning on the tunnel fans can increase the downside flow at the staircase. However exceeding high flow can produce disturbance and destroy the smoke stratification, so more area will be filled with smoke. Therefore, reasonable smoke management scheme is as important as smoke exhausting system capability.     

基于主成分分析的湖北省洪涝灾害风险评估模型构建

湖北省历年由洪涝灾害造成农作物受损严重,对湖北省进行洪涝风险评估十分必要。本文提出了一种定量化风险评估的模型建立方法,通过多源数据（气象、社会经济、地理特征等数据）提取到15个指标,采取主成分分析法确定各因子对于洪涝灾害的影响权重,建立风险评估模型,并运用地理信息系统(GIS)分析技术得出洪涝灾害风险区划图。在现有评估指标体系的基础上,通过网络爬虫方式获取更能反映防减灾能力的灾害应急指标;采用主成分分析方法降低模型建立中的主观因素。结果表明：（1）通过模型得到降雨与地势为湖北省洪灾发生的最主要因素;（2）湖北省中东部地区多为高风险区,其中东部武汉、黄石等长江干流途经地区处于重风险区;西南部多为中风险区,西北部在全省为低风险区。综上,该模型可为湖北省开展综合减灾、调整区域可持续发展结构、进行准确农情监测提供科学支撑和决策依据,具有重要的科学和实践意义。     

Commercial sex workers: Victims,vectors or fighters of the HIV epidemic in Cambodia?

Abstract: This paper looks at the knowledge, attitudes and behaviour of commercial sex workers (CSWs) in Cambodia regarding HIV/AIDS and condom use. The findings are based on semistructured interviews and focus groups with brothel‐based and self‐employed CSWs, and interviews with people who work with them. The respondents live in two towns near the Thai border served by Medecins Sans Frontiers sexually transmitted disease clinics set up to reduce the transmission of HIV. Most CSWs had attended the clinics. Knowledge of HIV and the ability of condoms to prevent infection was universal. The desire to use condoms with clients was also universal. Most CSWs were active and skilful in negotiating condom use with clients. However, many CSWs who wanted to use condoms failed to do so on occasion due to disparate power relationship with brothel owners and clients, and economic desperation. In addition, some exempted regular or special clients from condom use due to emotional isolation and misconceptions over susceptibility to HIV. The current 100% Condom Use Policy in place in Cambodia is not compatible with voluntary programmes such as the successful Medecins Sans Frontiers clinics. The government policy also fails to address the broader social and economic factors that make CSWs unable to enforce condom use when a client does not desire to do so.     

Contribution of durable disease resistance to sustainable agriculture

Durable disease resistance and sustainable agriculture are two important concepts that have not been defined well enough for many people to determine with certainty whether a particular entity fits into either category. While there is not agreement on either definition, there is little disagreement that each concept is a desirable objective. Ironically, both concepts can be reduced to `over a long period of time'. While most people would not argue with the indefinite characterization of either concept, disagreement quickly arises when consideration begins of how to achieve either. Most disease resistance that is rendered ineffective is race specific. The pathogen population is shifted genetically to defeat the resistance gene. When resistance is only partial, the population shifts are less likely to occur. Equally so, the more complex the genetics of the resistance, the more difficult it is for the pathogen to evolve to a form that can overcome the resistance. Throughout history, there are countless examples of major losses of crops when previous effective resistance has been rendered ineffective, causing severe hardship and even devastating famines, e.g., Irish potato famine. Fortunately, there are also examples of resistance that has given protection over an extended time, one is rust in maize. Ultimately, adding genetic complexity to many host plant resistances is likely to extend their effectiveness (greater durability). Similarly, adding biodiversity to the landscape for both plants and animals is likely to increase the resiliency of the ecosystem involved. In both cases, the derived food system will be more secure. This revised version was published online in August 2006 with corrections to the Cover Date.     

罗非鱼养殖意愿及影响因素实证研究——基于罗非鱼主产区263个农户的调查

为了研究中国罗非鱼养殖户的养殖意愿及其影响因素,以中国罗非鱼主产区263 个养殖户的调查数据为依据,采用二元Logit 模型对养殖户罗非鱼养殖意愿进行了实证分析。研究表明：养殖户主风险倾向情况、罗非鱼养殖年限、罗非鱼销售顺利与否、养殖户是否参加产业化经营组织、养殖户是否获得相关养殖培训和当地政府是否进行宣传或提供补贴等因素对罗非鱼养殖户养殖意愿有正向影响,罗非鱼养殖面积对罗非鱼养殖户养殖意愿有负向影响。提出主产区政府应对罗非鱼养殖进行合理的生产布局与规划,倡导规范、科学的健康生态养殖模式,加大政策扶持力度,增强罗非鱼养殖户的养殖意愿。     

Diversity in daytime and night‐time transpiration dynamics in barley indicates adaptation to drought regimes across the Middle‐East

A challenge to breeding drought‐tolerant barley in the Middle‐East is that precipitation and evaporative demand patterns dictate opposite water use strategies (conservative vs. risk‐taking). To characterize these strategies, we examined high‐resolution, whole‐plant transpiration rate (TR) responses to increasing vapour pressure deficit (VPD) and nocturnal TR (TR_N) dynamics among 25 local barley genotypes, using a novel phenotyping system. These traits were specifically selected because they exist under modalities enabling the expression of both strategies. The genotypes were selected from locations spread across a large aridity gradient represented by temperature and precipitation data spanning 30 years. Here, we uncovered a substantial diversity in TR responses to VPD where slopes of the linear responses correlated negatively with local maximal temperatures, pointing to opposite drought tolerance strategies. Low canopy conductance (low slopes) was associated with higher aridity, likely to enable water‐saving, while higher conductance was associated with wetter areas, likely to enable a more aggressive water use to maximize physiological activity. TR_N was highly diverse and represented up to 15% of maximal daytime TR, pointing to the possibility of increasing water‐saving by reducing TR_N. Furthermore, we detected pre‐dawn variation in TR_N that negatively correlated with local precipitation, indicating that a tighter circadian control is associated with adaptation to drought, consistently with a circadian resonance mechanism. These findings indicate that canopy conductance and TR_N are potentially beneficial to design drought‐tolerant barley germplasm adapted to different drought regimes taking place in the Middle‐East.     

Poverty and Local Governments: Economic Development and Community Service Provision in an Era of Decentralization

Social scientists have given substantial attention to poverty across U.S. localities. However, most work views localities through the lens of population aggregates, not as units of government. Few poverty researchers question whether governments of poorer localities have the capacity to engage in economic development and service activities that might improve community well‐being. This issue is increasingly important as responsibilities for growth and redistribution are decentralized to local governments that vary dramatically in resources. Do poorer communities have less activist local governments? Are they more likely to be engaged in a race to the bottom, focusing on business attraction activities but neglecting services for families and working people? We bring together two distinct literatures, critical research on decentralization and research on local development efforts, that provide contrasting views about the penalty of poverty. Data are from a unique, national survey of county governments measuring activity across two time points. The most consistent determinants of activity are local government capacity, devolutionary pressures, and inertia or past use of strategies. Net of these factors, levels and changes in poverty do not significantly impact government activity. There is no evidence the nations' poorest counties are racing to the bottom. Findings challenge views that poverty is a systematic structural barrier to pursuing innovative economic development policies and suggest that even poorer communities can take steps to build local capacity, resources, and networks that expand programs for local businesses and low‐wage people.     

As the world gets smaller, the chances of invasion grow

Summary While the issue of invasive alien species has important biological components, economic factors such as global trade deserve much greater attention for several reasons. First, virtually all of our planet’s ecosystems have a strong and increasing anthropogenic component that is being fed by increasing globalisation of the economy. Second, people are designing the kinds of ecosystems they find productive or congenial, incorporating species from all parts of the world through quicker and more efficient means of transportation. And third, growing travel and trade, coupled with weakening customs and quarantine controls, mean that people are both intentionally and inadvertently introducing alien species that may become invasive. The great increase in the introduction of alien species that people are importing for economic, aesthetic, accidental, or even psychological reasons is leading to more species invading native ecosystems, with disastrous results: they become invasive alien species (IAS) that have significant deleterious effects on both ecosystems and economies. This paper examines some of the important non-biological dimensions of the IAS problem, including historical, economic, cultural, linguistic, health, sociological, management, legal, military, ethical, and political dimensions. These are addressed in terms of the causes, consequences, and responses to the problem of IAS. These dimensions of IAS are fundamental, and successfully addressing the problem will call for greater collaboration between different economic sectors and among a wide range of disciplines. The Convention on Biological Diversity, the negotiations of the World Trade Organisation, and many other international agreements offer important opportunities for addressing the complex global problems of IAS through improved international cooperation.     

The challenges of maintaining wheat productivity: pests, diseases, and potential epidemics

Knowing pests and diseases that may cause injuries and are likely to affect plant health and quality is critical to minimizing the gap between attainable yield and actual yield. In this paper, we highlight concepts and strategies aimed at controlling major biotic constraints affecting wheat in intensive production systems and present emerging challenges, with a special attention to the developing world. Disease epidemics result from the combination of inoculum, favorable environment, and host susceptibility. Changes in cropping systems as a result of adoption of conservation agriculture may have serious implications. Necrotrophic pathogens such as those responsible for tan spot or septorias are likely to emerge, and Fusarium head blight may increase. However, resistance breeding combined with rotations, timely sowing, and irrigation or even fungicide utilization, if affordable, are part of integrated crop management practices that can minimize losses. In South Asia, the effect of spot blotch, a devastating foliar disease caused by Cochliobolus sativus, can be minimized by reducing physiological stress through timely sowing and adequate use of fertilizers, which demonstrates the complex relationships among crop physiology, disease resistance, and yield. Although some root rots that induce premature death of tillers in cooler high-yielding humid environments can be important, the dryland crown rot (Fusarium spp.), common root rot (C. sativus), and the cereal nematode (Heterodera spp. and Pratylenchus spp.) should not be ignored. These are all known to be much more damaging under suboptimal moisture (rainfed or supplementary irrigation), particularly where plant growth is stressed. Climate change is likely to modify the wheat disease spectrum in some regions, and pathogens or pests considered unimportant today may turn out to be potential new threats in future.     

2008年广西第三代稻纵卷叶螟大发生特点及原因简析

稻纵卷叶螟是广西水稻主要害虫之一, 年发生6～8代,其中第2、3代是早稻主害代。2008年,受虫源、气候因子和种植条件等因素的综合影响,广西第3代稻纵卷叶螟发生呈现发生范围广、面积大、成虫峰次多、峰期持续长、蛾量大、虫口密度高、为害期长、田间虫态复杂等特点,发生面积75.6万hm2,为建国以来最严重的大发生年。作者分析,其主要原因为：5月下旬到6月中旬,第3代发生期气候适宜;第2代残留基数大,外地迁入数量多,第3代成虫滞留量多;水稻生育期推后、插花田增多,稻纵卷叶螟食料充足;由于雨日多,劳动力紧张,以及应急防治农药缺乏,造成应急防治实施难度大等。     

Smoke Management Systems for Large Volume Space

Atria and other large volume space do not have the compartmentation that has traditionally been a major contributor of fire protection.The effectiveness of sprinklers in these large volume spaces is limited. For these reasons, smoke management systems for large volume spaces is of particular importance. Their primary goal is to maintain an enviroment in which the impact of smoke and heat on occupants is not life threatening. This involves keeping the height of the smoke layer above the highest level of occupancy for a defined period of time, longer than the expected time to evacuate the building. Three approaches to these systems are smoke filling , gravity smoke venting ,and smoke exhaust .This paper describes the design approaches to smoke management to achieve fire safety in atrium.     

棉花不同耐高温品系的SOD、POD、CAT活性和MDA含量差异及其对盛花期高温胁迫的响应

分别以耐高温、中度敏感与敏感型3个棉花品系为材料,分析了它们在不同发育时期叶片和花药中SOD、POD、CAT保护酶活性和MDA含量的差异及在盛花期高温胁迫下的变化。3个品系间叶片保护酶活性在苗期和盛蕾期几乎相同,在盛花期和结铃盛期耐高温显著高于敏感类型,而耐高温棉花叶片MDA含量自盛蕾期起显著低于敏感类型。花药保护酶活性随生育进程而逐渐增加,耐高温棉花花药SOD和POD活性在花粉粒成熟期才显著高于敏感类型,而CAT活性和MDA含量在整个发育时期均分别显著高于和低于敏感类型材料。盛花期高温胁迫显著地抑制叶片和花药的保护酶活性,导致MDA含量极显著地增加,但耐高温棉花叶片和花药保护酶活性的降低和MDA含量的增加幅度明显少于敏感类型。     

城镇化下留守农民社会资本培育的困境及化解

在城镇化持续推进下,人力资本与社会资本丰富的农民大量流向城市,致使留守农民社会资本急剧下降,在农村形成了一个巨大的社会资本缺口,加剧了留守农民贫困化,严重制约着农村全面发展。为此,培育留守农民社会资本,提高其运用社会资本能力以脱贫,是妥善解决三农问题与新农村建设的根本思路之一。但是,城乡发展对资源的争夺、留守农民自身资源的不足以及民间组织与农村精英的自利,使得培育与开发留守农民社会资本陷入诸多困境。为有效培育留守农民社会资本,宏观上,应进行城乡发展统筹规划,且重点向农村统筹;微观上,通过各类学校教育、基础设施建设、民间组织组建等各种途径,加强有利于社会资本培育的基础平台建设。     

Fijian adolescents’ understanding and evaluation of climate change: Implications for enabling effective future adaptation

Pacific Island countries are particularly vulnerable to future manifestations of climate change due to high coastline‐to‐land‐area ratios, and high dependence of inhabitants on natural ecosystems. While everyone in the Pacific Islands should participate in climate change adaptation activities, it is the young people, given they are the generation likely to not only bear the burden of climate change, but to lead and live effective climate change adaptation activities and strategies specific to their region, the involvement of youth is critical. Pacific Island youths are often marginalised within traditional decision‐making hierarchies, therefore they are typically excluded from participating in meaningful discussions at community and government levels. Discussions were held with 30 adolescents aged 14–18 years in Fiji to explore knowledge and experiences regarding climate change. Participants revealed their dismay at their inability to talk to family – who they consider are not doing enough – about what they consider as appropriate responses to climate change, recommending the help of an authoritative outsider who could speak to their community leaders and family. Discussions also revealed that Fijian youth could not distinguish between changes in the climate and normal weather events, attesting to the importance of climate‐change education and awareness‐raising efforts within the Pacific Islands more generally.