Locomotor activity rhythm in Drosophila melanogaster after 600 generations in an aperiodic environment

The locomotor activity rhythm of flies from four populations of Drosophila melanogaster, maintained under constant light for more than 600 generations, was recorded in continuous light (LL) and continuous darkness (DD) using four different protocols. The main objective behind these experiments was to estimate the proportion of flies exhibiting circadian rhythm of locomotor activity in LL, and to investigate whether this could be increased by subjecting the flies to various light regimes. About 26% of the flies exhibited a circadian rhythm of locomotor activity in LL, and the proportion increased to about 48% after an exposure to 12 h of darkness. About 77% of the flies exhibited a circadian locomotor activity rhythm in DD. Persistence of circadian locomotor activity rhythm in a considerable proportion of these flies suggests an intrinsic adaptive value to possessing circadian rhythmicity, derived, perhaps, from the need to synchronise various processes within the organism.     

遥感与地理信息系统对资源利用热点地区的初步应用——-以印度北部山地小流域为例

资源利用与资源退化在时间及空间领域上的表现有所分异。识别出那些受人为干扰严重且易于发生资源退化的区域(资源利用的热点地区),对这些区域给予重视并采取特殊的管理机制以避免资源的进一步退化和环境的恶化,对资源的可持续利用具有重要的现实意义。论文以印度北部山地小流域的研究为例,根据当地实际情况,选取4个参数作为评价指标,即资源利用的重要性、资源的需求程度、资源利用的可获取性以及人类活动造成的景观生态学的干扰指数,利用遥感技术和地理信息系统对资源利用热点地区的识别进行了初步探讨。通过研究,将该流域划分为3种区域,即高度敏感区、中度敏感区和低敏感区,分别体现了不同的资源退化在空间上的分布。     

Ecotoxicity studies of some organotin compounds

The ecotoxicities of three organic compounds containing spacer groups, an intermediate organotin premonomer, four organotin monomers, their homopolymers and six copolymers of tributylin α‐chloroacrylate (TCA) are reported against two microorganisms viz., Pseudomonas aeruginosa and Sarcina lutea and a larval species Anemia salina (Nauplii II). The organic compounds containing spacer group were less toxic whereas the monomers were found to be highly toxic. The homopolymers were found to be more toxic than that of tributyltin acrylate (TBTAA), tributyltin methacrylate (TBTMA) and tributyltin α‐Chloroacrylate (TCA). The toxicity of TCA copolymers increased with the increase in tributyltin (TBT) content in the polymer. From this study it was not possible to establish any relationship between the chemical nature of the comonomer with its toxicity.     

Identifying Potential Conflict Associated with Oil and Gas Exploration in Texas State Coastal Waters: A Multicriteria Spatial Analysis

Recent interest in expanding offshore oil production within waters of the United States has been met with opposition by groups concerned with recreational, environmental, and aesthetic values associated with the coastal zone. Although the proposition of new oil platforms off the coast has generated conflict over how coastal resources should be utilized, little research has been conducted on where these user conflicts might be most intense and which sites might be most suitable for locating oil production facilities in light of the multiple, and often times, competing interests. In this article, we develop a multiple-criteria spatial decision support tool that identifies the potential degree of conflict associated with oil and gas production activities for existing lease tracts in the coastal margin of Texas. We use geographic information systems to measure and map a range of potentially competing representative values impacted by establishing energy extraction infrastructure and then spatially identify which leased tracts are the least contentious sites for oil and gas production in Texas state waters. Visual and statistical results indicate that oil and gas lease blocks within the study area vary in their potential to generate conflict among multiple stakeholders.     

Assessing drivers of post-harvest losses: tangible and intangible resources’ perspective

Environment, Development and Sustainability - Many stakeholders in agro-food industry are concerned about sustainability, especially in addressing post-harvest loss (PHL). However, resources...     

The influence of sociopolitical,natural, and cultural factors on international tourism growth: a cross-country panel analysis

This study employed a cross-country panel data model to investigate the relative contributions of sociopolitical, natural and cultural characteristics and national tourism policies to international tourism growth. International tourism receipt data were adjusted for country-specific inflation and then analyzed in relation to standardized measures of the World Economic Forum’s “pillars of tourism competitiveness.” Results indicated that international tourism receipts are more responsive to policies and regulations favoring tourism, abundance of natural resources, richness in cultural heritage, and health and hygiene than they are to infrastructure, safety, price competitiveness, and other variables. Findings highlight key factors associated with international tourism receipts and provide a general framework that could inform policies and management strategies designed to promote sustainable international tourism development.     

Capturing forest dependency in the central Himalayan region: Variations between Oak (<Emphasis Type="Italic">Quercus</Emphasis> spp.) and Pine (<Emphasis Type="Italic">Pinus</Emphasis> spp.) dominated forest landscapes

Our study explores the nexus between forests and local communities through participatory assessments and household surveys in the central Himalayan region. Forest dependency was compared among villages surrounded by oak-dominated forests (n = 8) and pine-dominated forests (n = 9). Both quantitative and qualitative analyses indicate variations in the degree of dependency based on proximity to nearest forest type. Households near oak-dominated forests were more dependent on forests (83.8%) compared to households near pine-dominated forests (69.1%). Forest dependency is mainly subsistence-oriented for meeting basic household requirements. Livestock population, cultivated land per household, and non-usage of alternative fuels are the major explanatory drivers of forest dependency. Our findings can help decision and policy makers to establish nested governance mechanisms encouraging prioritized site-specific conservation options among forest-adjacent households. Additionally, income diversification with respect to alternate livelihood sources, institutional reforms, and infrastructure facilities can reduce forest dependency, thereby, allowing sustainable forest management.     

Statistical inferences from measured data on concentrations of naturally occurring radon,thoron, and decay products in Kumaun Himalayan belt

Environmental Science and Pollution Research - Regional averages of radon, thoron, and associated decay product concentration are reported to be higher than their respective global averages in...