The spatial implications of the functional proximity deriving from air passenger flows between European metropolitan urban regions

Until recently the traditional spatial configuration of the European geography was based upon the core-periphery model. The ‘pentagon’, broadly defined as lying between London, Paris, Milan, Munich and Hamburg, was seen as the core area characterised by having the highest concentration of economic development in the European Union (EU), with the remainder of the European territory viewed as peripheral, albeit to varying degrees. In a number of cases such peripheral areas equated with clear regional disparities. The elaboration of the European Spatial Development Perspective (ESDP) (CEC, European spatial development perspective, towards balanced and sustainable development in the territory of the European Union, 1999) challenged this core-periphery model. European spatial planning policies, aimed at encouraging social and economic, and with ever increasing importance, territorial cohesion, seek amongst other aspects to encourage the development of a balanced and polycentric urban system. This paper adopts a network analysis approach to the analysis of air passenger flows between some 28 principal European metropolitan urban regions. The evaluation of these flows contributes to an enhanced comprehension of the spatial dynamics of the European metropolitan territory which goes beyond that deriving from the more standard analyses of the individual components of the urban system. Several indicators are used, deriving from gravitational modelling techniques, to analyse the complexity of the air passenger flows. A multidimensional scaling (MDS) technique is introduced in order to interpret and visualise the resulting spatial configuration and positioning of the different metropolitan centres within the conceptual European ‘space of air passenger flows’, thereby contrasting with the more traditional map-based geographical image of Europe, based upon Cartesian coordinates.

Functional responses for zooplankton feeding on multiple resources: a review of assumptions and biological dynamics

Modelers often need to quantify the rates at which zooplankton consume a variety of species, size classes and trophic types. Implicit in the equations used to describe the multiple resource functional response (i.e. how nutritional intake varies with resource densities) are assumptions that are not often stated, let alone tested. This is problematic because models are sensitive to the details of these formulations. Here, we enable modelers to make more informed decisions by providing them with a new framework for considering zooplankton feeding on multiple resources. We define a new classification of multiple resource responses that is based on preference, selection and switching, and we develop a set of mathematical diagnostics that elucidate model assumptions. We use these tools to evaluate the assumptions and biological dynamics inherent in published multiple resource responses. These models are shown to simulate different resource preferences, implied single resource responses, changes in intake with changing resource densities, nutritional benefits of generalism, and nutritional costs of selection. Certain formulations are further shown to exhibit anomalous dynamics such as negative switching and sub-optimal feeding. Such varied responses can have vastly different ecological consequences for both zooplankton and their resources; inappropriate choices may incorrectly quantify biologically-mediated fluxes and predict spurious dynamics. We discuss how our classes and diagnostics can help constrain parameters, interpret behaviors, and identify limitations to a formulation's applicability for both regional (e.g. High-Nitrate-Low-Chlorophyll regions comprising large areas of the Pacific) and large-scale applications (e.g. global biogeochemical or climate change models). Strategies for assessing uncertainty and for using the mathematics to guide future experimental investigations are also discussed.     

Soluble organic compounds in fog and cloud droplets: what have we learned over the past few years?

We have recently set up a new procedure for characterising the water soluble organic compounds (WSOC) in fog water, for which information is still rather limited. Fog samples collected during the 1998–1999 fall–winter season in the Po Valley (Italy) were analysed following this procedure, which allows a quantitative determination of three main classes of organic compounds (neutral species, mono- and di-carboxylic acids, polycarboxylic acids), together accounting for ca. 85% of the total WSOC. This procedure also provides information on the main chemical characteristics of these three classes of compounds (functional groups, aliphatic vs. aromatic character, etc.). The enhanced chemical knowledge on fog/cloud chemical composition opens new scenarios as far as chemical and microphysical processes in clouds and fogs are concerned.     

Li2O—B2O3功能材料体系研究概述

本文介绍了碱金属硼酸盐的一些基本知识，主要回顾了其中Ｌｉ２Ｏ—Ｂ２Ｏ３体系的研究历史，讨论了该体系结构与性质的关系并总结了Ｌｉ２Ｏ－Ｂ２Ｏ３晶态及非晶态物质作为新型功能材料的研究进展。     

基于陆海统筹的海岸带空间功能分区——以宁波市为例

海岸带空间功能分区是优化海岸带开发与保护的基础性工作,在国土空间规划体系中具有重要作用。当前我国海陆功能分区在分区层级、分区方法等方面并不一致,导致海岸带保护与开发利用失衡。本文在梳理国内外海岸带空间功能分区研究的基础上,从陆海统筹角度出发,构建海岸带空间功能分区体系,并以宁波市为例进行验证,在优先划定生态保护区基础上,对海陆空间进行适宜性评价,根据评价结果确定功能分区。结果表明：（1）宁波市海岸带功能区中生态保护区面积占比约为60%,海陆一体发展区占比约为22.3%,海洋发展区占比约为12.5%,陆地发展区占比约为5.2%;(2)宁波市开发利用功能区空间分布与以临港产业、海洋服务业和海洋渔业为基础的海洋经济发展导向相符。海岸带空间功能分区要以生态保护为底线,以优化空间布局为导向,为优化海岸带开发与保护提供有力支撑。     

Reproductive biology and seasonality of the Indo-Australasian mysid Mesopodopsis orientalis (Crustacea: Mysida) in a tropical mangrove estuary,Malaysia

A year-round survey of the tropical shallow-water mysid Mesopodopsis orientalis (Tattersall, 1908) (Crustacea, Mysidacea) was conducted in the Merbok mangrove estuary, northwestern Peninsular Malaysia. The mysid formed dense aggregations at the river's edge close to the mangrove forest during the daytime, but very few were captured elsewhere in the estuary system. The sampled population was found in a wide range of salinities from 16 to 32, demonstrating broad euryhalinity, and the number of the catch at the littoral zone ranged from 11.8 to 2273 ind m⁻². The overall annual mean was 709.2 ind m⁻². Females predominated over males in the entire population, and brooding females were present at every monthly sample, indicating that reproduction is continuous year round. The clutch size positively correlated with female body length. The diameter of eggs (Stage I embryos) was unaffected by the seasonality and independent of the maternal size within an observed size range. The life history pattern of the estuarine population of M. orientalis showed close similarity to that of the coastal counterpart. However, the former was found to produce fewer but larger eggs, and the specimens in this population were larger than those in the coastal population at the embryo, juvenile, and adult stages. This evidence indicates that the life history features of the estuarine population would differ to some degree from those of the coastal counterpart.     

沙虫干呈味及功能性成分研究

对沙虫干抽提物成分的组成进行的研究结果表明 :游离氨基酸含量 w为 10 .3% ,占抽提物含氮物质的 77.9%。抽提物组成中 ,呈甘味的 Gly(3.2 % )、Ala(2 .5% )和呈鲜味的 IMP(0 .2 7% )、Glu(0 .2 5% )、琥珀酸 (0 .35% )等成分同沙虫干独特的风味有关 ,Na 、Cl-等无机离子也同其呈味相关。此外 ,牛磺酸含量 w高达 3.2 % ,是富含牛磺酸的一种海洋生物 ;精氨酸的含量 w亦较高 ,为 1.2 %。     

海洋功能区划与海洋生态红线关系探讨

海洋生态红线制度是我国"五位一体"文明建设的具体要求。为进一步在自然科学与人文科学的联结点上探求深入开展生态红线工作的可能性,文章对比了实施多年的海洋功能区划与历史新阶段提出的海洋生态保护红线的概念和内涵,剖析了两者之间的区别与联系,指出海洋功能区划与海洋生态红线区划在法律地位和管控制度等方面具有一致性,在划分目标、空间管理及划分方法上具有差异性,海洋功能区划以"使用"为主,海洋生态红线以"保护"引领。在此基础上,建议未来海洋生态红线工作的开展可从海洋功能区划借鉴经验,建立完善的管控评估制度,确立生态保护红线的优先地位,处理好海洋功能区划与海洋生态红线区划的关系。同时,海洋生态红线区划应以维持海洋生态系统结构稳定和提高海洋生态系统服务功能为目标,将区域资源环境承载力评估作为一项参考指标,限制低承载区的开发利用,保证海洋生态环境健康可持续发展。     

Changes in survivorship,behavior, and morphology in native soft‐shell clams induced by invasive green crab predators

Many studies on invasive species show reduced native densities, but few studies measure trait‐mediated effects as mechanisms for changes in native growth rates and population dynamics. Where native prey face invasive predators, mechanisms for phenotypic change include selective predation, or induced behavioral or morphological plasticity. Invasive green crabs, Carcinus maenas, have contributed to declines in native soft‐shell clams, Mya arenaria, in coastal New England, USA. We tested the hypothesis that clam ability to detect chemical cues from predators or damaged conspecifics would induce greater burrowing depth as a refuge from invasive crabs, and greater burrowing would require increased siphon growth. To determine how crab predation affected clam survivorship and phenotypic traits in the field, clams in exclosure, open, and crab enclosure plots were compared. Crab predation reduced clam density, and surviving clams were deeper and larger, with longer siphons. To determine whether the mechanism for these results was selective predation or induced plasticity, phenotypes were compared between clams exposed to chemical cues from crab predation and clams exposed to seawater in laboratory and field experiments. In response to crab predation cues, clams burrowed deeper, with longer siphons and greater siphon mass. Overall, crab predation removed clams with shorter siphons at shallow depths, and crab predation cues induced greater burrowing depths and longer siphons. Longer siphons and greater siphon mass of deeper clams suggests clams may allocate energy to siphon growth in response to crabs. By determining native behavior and morphological changes in response to an invasive predator, this study adds to our understanding of mechanisms for invasive impacts and illustrates the utility of measuring trait‐mediated effects to investigate predator–prey dynamics.