心脏前负荷减低对主动脉压及主动脉扩增指数的影响

目的 了解心脏前负荷减低对中心动脉压及主动脉扩增指数的影响.方法 10例健康志愿者,行下肢负压(LBNP)抽吸造成不同程度前负荷减低.采用超声心动图检测心输出量的变化;采用中心动脉压力分析系统(SphymoCor)检测桡动脉压力波形,经平均转换功能形成中心动脉压力波形.结果 ①随着下肢负压的加大,上腔静脉血流进行性减低,在-30mmHg阶段,S波减低22.4%,VTIs+d减低了15.8%,同时SV减少24.7%,CO减少18.7%;②中心动脉收缩压(CSBP)除在-30mmHg阶段轻度下降外,在-10及-20mmHg阶段没有明显改变,中心动脉舒张压(CDBP)在各个负压阶段没有明显改变;③主动脉压力波P1在各个负压阶段均明显下降,在-30mmHg阶段,P1减少了19.6%[(28.2±5.02)mmHg vs.(22.65±3.08)mmHg, P＜0.01],而总外周阻力(TPR)在各负压阶段均较基础阶段明显升高,在-30mmHg阶段升高21.3%[(16.0±2.9)(mmHg·min)/L vs.(20.3±3.4)(mmHg·min)/L, P＜0.001].主动脉扩增指数(AI)无明显改变.结论 前负荷减低使中心主动脉压及主动脉压力波P1降低,同时使TPR升高,由于TPR的升高抵消了P1 的降低,因而AI保持不变.     

Workshop 6: The public agenda: What is working and what is missing

Workshop 6 topics covered social inclusion, the informal transport sector, transport in developing countries and sustainability. The strong connections and complimentary goals were noted, where solutions to social exclusion and greenhouse gas reduction can both be realised with good transport and urban planning. There is an opportunity for developing countries to avoid the transport mistakes in many developed countries, such as car dependence. This will involve the development of infrastructure that offers accessible public transport to the majority of people, providing resources to the informal transport system and integrating this with public transport. The workshop considered specific issues such as rural transport, new technology, car tolls to subsidise public transport, safety issues with informal transport and the failure to evaluate the longer-term impacts of many major transport infrastructure developments. Recommendations were made in relation to research and policy and future Thredbo topics.     

Bus routing strategies in a transit market: A case study of Hong Kong

Conventionally, the objective of transit routing is often set either to minimize the total operational cost, subject to a given level of service quality, or to maximize the service quality at a given acceptable cost. In a deregulated, commercial‐based environment however, such as bus and railway operations in cities of the UK and Hong Kong where several private firms compete in route‐based or area‐based market, routing becomes one of the means for higher returns rather than just for cost saving. In such a case, how do the transit providers set up their routes for profit‐maximization? Will the routing based on the provider's objective meet the user's objective? How do government regulations and policies affect the choice of transit provider's routing strategy? To answer these questions, we first examine the relationship between the objectives of users and transit providers, set up criteria for transit routing quality, and then investigate the possible routing configurations/patterns for a hypothetical case. These criteria include (1) the load factor of transit, (2) the level of route directness, (3) the level of route overlapping, and (4) the total number of routes and (5) the average of route length. These measures are finally applied to a real case in Hong Kong to examine the route changes of Kowloon Motor Bus from 1975 to 1995. The result of the empirical case reveais how key measures such as load factor are controlled by the bus operator and affected by government policies and how the bus routing pattern was adjusted to meet users' need. Facing the dilemma as evident in Hong Kong between the route directness and the efficiency of road use, we suggest that a rational multi‐modal routing structure be put in place if an institutional solution is introduced so that bus and other transit modes can form a sharing program or an alliance.     

Social exclusion: What can public transport offer?

A new workshop on ‘Social exclusion: What can public transport offer?’ was introduced in the Thredbo 10 program. The workshop examined the concept of social exclusion in a transport context, looking briefly at the history and comprehensiveness of the term for social policy in transport. Other concepts, such as well-being and social capital, were determined to be also needed. While important research was reported to the workshop, it was clear that social exclusion was at an early stage of empirical development. Gaps were highlighted, particularly in evaluation and cost-benefit analysis. Examples of service systems designed to address social exclusion were presented at the workshop, revealing the need to better understand governance arrangements. The workshop developed recommendations for future research and policy, particularly emphasising the need to integrate social outcomes with economic and environmental transport policy at the strategic, tactical and operational levels. Finally, ideas for further exploration of social exclusion in Thredbo 11, were outlined.     

Inshore Stocks of Atlantic Cod Are Important for Rebuilding the East Coast Fishery

Cod (Gadus morhua) inhabit not only the famous fishing banks of the Northwest Atlantic continental shelf, but also inshore waters from Labrador to New England. Relatively little is known about the life history of inshore cod, their historic levels of abundance, and their relationship to offshore stocks. Inshore cod stocks along the East Coast should be managed under a new paradigm that recognizes the importance of these fish to the stock complex. Recently documented fishers' ecological knowledge (FEK) suggests inshore stocks of cod may exist along the Newfoundland and Labrador coastline that have yet to be scientifically documented. Coastal communities adjacent to the local population of cod in Gilbert Bay, Labrador have initiated efforts to protect and manage this stock locally through a co-management approach. The Gilbert Bay experience, FEK, and related science and education could provide insight into ways to protect and enhance the health of local stocks remaining along the northeast coast of North America.     

Cost allocation by uniform traffic removal— Theoretical discussion and example highway cost applications

We propose four properties for equitable roadway cost allocations: (a) allocated costs should be based on full cost recovery, (b) allocated costs must be non-negative for any traveler group, (c) cost allocations should be additive, and (d) cost allocations should be consistent where equivalency factors among traffic categories exist. For cases with well-behaved cost functions, the uniform traffic removal technique discussed here uniquely satisfies these four properties and should be used whenever the four allocation properties are desired. Example applications as well as cases in which cost functions are not well behaved are discussed.     

Assessing the Impacts of Gender Integration in Ghana’s Fisheries Sector

Abstract

This article presents the results of an impact assessment of a component of a large scale USAID sustainable fisheries management project initiative aimed at integrating gender and strengthening the role of women in fisheries management in Ghana. The assessment is based on a literature review and qualitative field data collection. It assessed gender integration from three entry points: improving the Ghanaian policy environment for gender in fisheries, empowering women post-harvest processors, and engaging women gleaners in fisheries co-management. The assessment found that an important milestone was the adoption and implementation of the Ghanaian Fisheries Sector’s National Gender Mainstreaming Strategy in 2016. Summarizing the impacts on local post-harvest processors and gleaners, the assessment found that female post-harvest processors have increased capacity, confidence, and engagement in fisheries management. Gender mainstreaming efforts have succeeded in challenging cultural norms about women’s role in fisheries. Women have been exposed to sustainable fisheries management and are better equipped with the knowledge and leadership skills to advocate for good fisheries practices, which they actively demonstrate.