Trapped in Jobless Household Areas: the spatio-temporal dynamics of children in jobless households in metropolitan Australia

Child disadvantage is an important issue in Australia today and is one of the key policy target areas of the Federal government. Child disadvantage not only affects child wellbeing in the present time but can also inhibit their future achievements. As well as individual- and family-level effects, there is growing evidence that child wellbeing and achievement is highly affected by the environment in which children grow up, and what resources and role models are available to them in their surrounding areas. In this paper, we examine the spatial clustering of children in jobless households through the computation of the Global and Local Moran's statistics, for the Sydney and Melbourne metropolitan regions, and observe how these clusters have changed between the 2001 and 2006 census years. We find that there are significant spatial clusters of children in jobless households in both periods, suggesting that ‘place’ is a driver of this particular phenomenon. Further, we observe an expansion of ‘hot spots’, in both Sydney and Melbourne, suggesting that areas with high proportions of children in jobless households have both persisted and increased despite the sizeable economic growth in Australia over the same period.     

Road investment as enabling local economic development? Evidence from a rural Philippine fishing village

This paper investigates how efforts to achieve local economic growth conflicted with long‐term sustainable resource use when road accessibility was improved between a supply area – the households and household firms in a Philippine fishing village, Dinahican, previously hampered by very poor transport conditions and accessibility – and its major market. Findings indicate that improved road access to big fish markets stimulated investment in production enhancing inputs, which allowed increased fish landings and sales outside Dinahican, together with employment and incomes. At the same time, poorly implemented fisheries resource management resulted in overfishing in municipal waters and obvious disparities in access to productive resources. Thus, while road investment in relatively inaccessible rural resource rich areas may spur economic development as an underutilized production potential is released, it can facilitate resource depletion and intensify an unequal distribution of benefits if the enforcement of laws and regulations is lacking. In the case of Dinahican, coordination between infrastructure supply and the implementation and enforcement of fisheries resource management is found to be urgently needed.     

中国水资源利用效率驱动效应测度及空间驱动类型分析

综合考虑产业用水效率、产业用水结构、经济水平、水资源禀赋及水资源开发利用率5个因素对中国用水效率的影响,基于扩展的Kaya恒等式建立因素分解模型,应用LMDI分解方法对1997~2008年中国用水效率变化进行分解分析,计算各驱动效应因素的相对贡献率,测度它们的影响程度和方向。结果表明:产业用水效率效应和经济水平效应是影响中国用水效率变化的最显著因素。通过计算各驱动效应的绝对贡献率,采用最小方差法将中国31个行政区(港澳台除外)确定为4种空间驱动类型,进而分析用水效率变化驱动效应的分布特点。研究结果对于正确理解中国用水效率的变化与经济发展之间的关系以及产业结构的调整与可持续发展研究具有一定的参考价值。     

The influence of salinity on toxicological effects of arsenic in digestive gland of clam Ruditapes philippinarum using metabolomics

Ruditapes philippinarum,a clam that thrives in intertidal zones of various salinities,is a useful biomonitor to marine contaminants.We investigated the influence of dilution to 75% and 50% of normal seawater salinity(31.1) on the responses of the digestive gland of R.philippinarum to arsenic exposure(20 μg/L),using nuclear magnetic resonance(NMR)-based metabolomics.After acute arsenic exposure for 48 h,salinity-dependent differential metabolic responses were detected.In normal seawater,arsenic exposure increased the concentrations of branched-chain amino acids,and of threonine,proline,phosphocholine and adenosine,and it decreased the levels of alanine,hypotaurine,glucose,glycogen and ATP in the digestive glands.Differential changes in metabolic biomarkers observed at lower salinity(～23.3) included elevation of succinate,taurine and ATP,and depletion of branched-chain amino acids,threonine and glutamine.Unique effects of arsenic at the lowest salinity(～15.6) included down-regulation of glutamate,succinate and ADP,and up-regulation of phosphocholine.We conclude that salinity influences the metabolic responses of this clam to arsenic.     

旅游业空间经济效应的特征与变化——以湖南省地市为例

运用变异系数、基尼系数及多变量Moran’s I等分析方法,从规模相对差异、空间分布集中度与空间关联性等方面分析了2001―2010年湖南省地市旅游业内部差异与外部关联性的空间经济效应。论证了旅游业区域差异的不断缩小并不表明其必然具有缩小区域经济差异的作用。即在区域经济差异扩大时,湖南省旅游业规模相对差异的逐渐缩小只表明了其扩大区域经济规模相对差异的效应在不断减弱;而空间分布集中度的持续降低则表明其由起初的扩大效应不断减弱逐渐转变为缩小效应的不断增强。在外部关联性的空间经济效应上,总体上旅游业的外部空间关联性并未起到扩大区域经济差异的显著效应;但在局部上旅游业空间关联效应的增强却强化了已形成的经济差异格局,具有扩大区域经济局部差异的作用态势。     

Crayfish and fish as bioturbators of streambed sediments: Assessing joint effects of species with different mechanistic abilities

Many studies illustrate that bioturbating animal species individually affect aquatic sediments through diverse mechanistic abilities, whereas assessments of joint effects of such species on sediments are relatively rare. Such joint effects have implications for real systems, in which different bioturbators coexist, but are difficult to predict for two reasons. First, they can be additive (being the sum of the individual effects of each species) or they can be positive or negative interactive (being greater or smaller than the sum of the individual effects). Second, if interactive, they can depend on biotic interactions that affect the bioturbating activities of the species and/or they can depend on physical interactions among bioturbator-induced sediment modifications. Using experimental streams, we assessed such joint effects on gravel–sand sediments for flow and sediment conditions preferred by barbel (Barbus barbus) but also used by gudgeon (Gobio gobio) and, in a second experiment, for flow and sediment conditions preferred by both male crayfish (Orconectes limosus) and gudgeon. These species have different mechanistic abilities to affect gravel and/or sand in stream beds. In each experiment, we measured (i) the transport of gravel and sand at baseflow (during 12 experimental days); (ii) four sediment surface characteristics (after 12 d); and (iii) the critical shear stress (τ_c) causing incipient gravel and sand motion during experimental floods (after 12 d). Gudgeon contributed differently to the joint effects in the two experiments, which related to its individual weight, prevailing baseflow shear stress, sediment particle weight, and sediment mixture (availability of surface sand). Overall, the species pairs had predominantly negative interactive joint effects on the sediment variables assessed by us. Both a literature survey and observations during the experiments provided no evidence for direct biotic interactions between barbel and gudgeon or crayfish and gudgeon, so one would reasonably associate their negative interactive effects on the sediments with physical interactions among bioturbator-induced sediment surface modifications. Individually, each species reduced the percentage of sand in the surface layer and the surface algal cover to relatively low values so that the species pairs could not accomplish much greater joint effects on these variables, explaining their negative interactive effects on them. As algal cover particularly affected the τ_c for gravel and sand, the negative interactive effects of the animals on this surface variable chained toward the τ_c for the sediments, on which the species pairs also had negative interactive effects. Such chained negative interactive effects on sediment variables are seemingly a general pattern of joint bioturbator effects on aquatic sediments, i.e., the many so far described single-species effects should be smaller than their sum if the species coexists in nature.     

空间经济计量模型在区域科学研究中的应用述评

空间经济计量模型把空间自相关和空间异质性融入普通回归分析中,近些年来该方法不论是理论探讨还是应用研究均呈现爆炸式增长。通过回顾众多研究成果,总结得出国外该模型广泛应用于经济收敛、技术扩散、税收、投资、人口与就业、犯罪、环境科学、公共卫生等领域;指出由于考虑空间效应对区域经济社会要素的影响,因此具有其它模型无法比拟的优势,尤其是在区域科学研究中,有助于制定有效的区域政策;相比之下,中国在社会领域的应用研究尚显薄弱。     

弹塑性变形条件下围岩-支护相互作用全过程解析

围岩-支护作用机制是正确认识支护结构对围岩进行有效支护作用的基础理论问题。根据开挖面的空间效应及Hoek拟合方程计算了某工程实例的巷道顶板径向位移沿巷道纵向剖面方向分布的曲线,建立了围岩-支护耦合作用的力学模型,进而建立了描述巷道顶板径向位移与力学模型中的虚拟支护力的关系的数学模型。通过对数学、力学模型的解析与分析,研究了围岩-支护在其相互作用的全过程中的相互作用路径。在此基础上,对弹塑性变形阶段围岩-支护的相互作用原理给出了最新的认识。应用该研究成果,对某工程实例进行了支护作用效果的计算与分析研究。本文的研究成果实现了对围岩-支护耦合作用的全过程解耦,可以对围岩-支护的相互作用进行实时地预测或再现。     

软岩下桥隧相连段车辆冲击效应模型试验研究

为研究软弱围岩（Ⅳ、Ⅴ级）条件下桥、隧相连段在后期运营中车辆荷载及其冲击作用下的力学行为、作用效应等,依托相关工程实例开展了系统的室内模型试验研究。结合桥、隧相连工程的实际特点,依据相似理论,给出了模型试验中桥、隧结构及洞周岩土体各物理量间的相似关系,对模型试验方法进行了系统的分析和阐述。通过模型试验研究表明,Ⅳ、Ⅴ级围岩条件下的桥、隧相连段中,运营中的汽车荷载及其冲击作用,易使桥梁、隧道衬砌关键部位产生不利力学效应或结构损伤,使桥梁跨中、搭接端及洞底产生过大位移或沉降,并易使隧道洞口围岩稳定性降低等。因此,对桥隧相连段的桥、隧及洞口围岩各关键部位宜采取局部加强措施,以避免各种损伤或病害的发生