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1.
While there are numerous wildlife ecology studies in lowland areas of Nepal, there are no in‐depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai Arc. We investigated tiger, leopard and prey densities across this understudied habitat. Our camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park (CNP). We used 161 trapping locations and accumulated 2097 trap‐nights in a 60‐day survey period during the winter season of 2010–2011. In addition, we walked 136 km over 81 different line transects using distance sampling to estimate prey density. We photographed 31 individual tigers, 28 individual leopards and 25 other mammalian species. Spatial capture–recapture methods resulted in lower density estimates for tigers, ranging from 2.3 to 2.9 tigers per 100 km2, than for leopards, which ranged from 3.3 to 5.1 leopards per 100 km2. In addition, leopard densities were higher in the core of the Churia compared to surrounding areas. We estimated 62.7 prey animals per 100 km2 with forest ungulate prey (sambar, chital, barking deer and wild pig), accounting for 47% of the total. Based on prey availability, Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower, perhaps indicating that the tiger population is below carrying capacity. Our results demonstrate that Churia habitat should not be ignored in conservation initiatives, but rather management efforts should focus on reducing human disturbance to support higher predator numbers.  相似文献   
2.
The accuracy and interaction among global positioning system (GPS) horizontal accuracy, differential GPS (DGPS) sampling frequencies and machine delay times of a hypothetical variable rate applicator for nitrogen (N) fertilizer application based on an application map in Florida citrus were studied. Parameters studied included: five GPS horizontal accuracy levels, two levels of DGPS horizontal accuracy, two DGPS sampling frequencies and two machine delay times. Two integrated models were developed which documented the effects of the parameters. Machine delay time was the most important factor and GPS horizontal accuracy was the second most important.  相似文献   
3.
脂质是一类具有独特生理功能活性的化合物,参与调节多种植物应答非生物胁迫过程,对维持植 物组织中生理动态平衡至关重要。脂质组学(Lipidomics)自 2003 年被提出后,已迅速发展成为对脂质整体系 统分析的一门新兴学科,为传统代谢组学注入新的技术支撑,有助于阐明脂类物质在植物中的代谢调控机制。 同时,质谱成像技术因其具有无标记、非特异性、高灵敏度、多物质同时分析等优势,被广泛应用到植物组织 中各类脂质分子的空间分布研究。介绍了脂质组学和质谱成像技术的研究现状,重点综述脂质分析技术在植物 种子脂质代谢调控研究中的最新进展,特别是新兴质谱成像技术在植物种子中脂类物质的成像应用。脂质组学 和质谱成像技术作为目前多组学技术的重要补充,将为植物代谢途径和调控机制的深入探究提供新的契机。亚 微米级高空间分辨率质谱成像技术的不断发展,将进一步推动植物在空间分辨水平的脂质代谢调控网络的深入 解析和前沿应用研究。  相似文献   
4.
ABSTRACT:   Wild adult maturing and immature female Japanese flounder Paralichthys olivaceus were collected in June 2004 and January 2005, respectively, to clarify a possible role of gonadotropin-releasing hormones (GnRHs) in reproduction. Levels of salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and sea bream GnRH (sbGnRH) in the brain and pituitary were examined by time-resolved fluoroimmunoassay. Three forms of GnRHs were detected in the discrete brain at various levels. In the pituitary of both maturing and immature fish, sbGnRH was abundant together with a pronounced amount of sGnRH, whereas cGnRH-II was almost below the detectable limit. In maturing fish, levels of sbGnRH were high in the telencephalon, hypothalamus and pituitary, while levels of sbGnRH of immature fish were very low in these regions. These results indicate that sbGnRH is mainly responsible for gonadotropin secretion, and that sbGnRH in the anterior part of the brain is associated with gonadal maturation in the Japanese flounder.  相似文献   
5.
Spatially explicit fisheries simulation models for policy evaluation   总被引:3,自引:0,他引:3  
This paper deals with the design of modelling tools suitable for investigating the consequences of alternative policies on the dynamics of resources and fisheries, such as the evaluation of marine protected areas (MPA). We first review the numerous models that have been developed for this purpose, and compare them from several standpoints: population modelling, exploitation modelling and management measure modelling. We then present a generic fisheries simulation model, Integration of Spatial Information for FISHeries simulation (ISIS‐Fish). This spatially explicit model allows quantitative policy screening for fisheries with mixed‐species harvests. It may be used to investigate the effects of combined management scenarios including a variety of policies: total allowable catch (TAC), licenses, gear restrictions, MPA, etc. Fisher's response to management may be accounted for by means of decision rules conditioned on population and exploitation parameters. An application to a simple example illustrates the relevance of this kind of tool for policy screening, particularly in the case of mixed fisheries. Finally, the reviewed models and ISIS‐Fish are discussed and confronted in the light of the underlying assumptions and model objectives. In the light of this discussion, we identify desirable features for fisheries simulation models aimed at policy evaluation, and particularly MPA evaluation.  相似文献   
6.
The impacts of climate change have been demonstrated to influence fisheries resources. One way climate has affected fish stocks is via persistent shifts in spatio‐temporal distribution. Although examples of climate‐forced distribution shifts abound, it is unclear how these shifts are practically accounted for in the management of fish stocks. In particular, how can we take into account shifting stock distribution in the context of stock assessments and their management outputs? Here, we discuss examples of the types of fish stock distribution shifts that can occur. We then propose a decision tree framework of how shifting stock distributions can be addressed. Generally, the approaches for addressing such shifts fall into one of three main alternatives: re‐evaluate stock identification, re‐evaluate a stock unit area, or implement spatially explicit modelling. We conclude by asserting that the approach recommended here is feasible with existing information and as such fisheries managers should be able to begin addressing the role of changes in stock distribution in these fish stocks. The implications of not doing so could be notably undesirable.  相似文献   
7.
Settlement Strategy and Present Main Problem of Our Country Countryside   总被引:1,自引:0,他引:1  
从分析中国农村的基本国情、市场经济体制下、城镇化进程中及农业推广体系改革过程中农村存在的主要问题入手,指出解决当前中国农村的主要问题、发展农村经济是全面建设小康社会的首要问题和难点问题,是长期的问题,必须常抓不懈。并提出解决问题的八条对策:一是正确认识高度重视;二是加快城镇化进程,促进农村劳动力转移;三是赋予农民同等国民待遇;四是延长农业产业链;五是完善国家对农业的支持保护体系;六是发展农民专业协会和其他代表农民利益的组织;七是严格保护耕地,解决好失地农民的生计;八是完善理顺农技推广体系。  相似文献   
8.
  • 1. Anthropogenic climate change affects both phenology and distribution patterns of the world's biota including marine species. During the last decade, species distribution models have been more frequently used to assess the potential distributions of species and possible effects of climate change. However, unlike for terrestrial species, there have been few investigations assessing climate change effects on distribution patterns of marine organisms.
  • 2. An overview of marine species distribution modelling is given. Possibilities of how to characterize and project the environmental niches of species onto climatic change scenarios are highlighted and novel techniques for addressing specific needs in a 3‐D context are proposed. A detailed introduction into different modelling tools and databases for environmental parameters given provides a starting point for the application of these models.
  • 3. Application of a species distribution model and its projections onto a glacial and future scenario on a global scale are presented for the great white shark (Carcharodon carcharias) for illustrative purposes. An approach for addressing marine migratory species with seasonal distribution patterns is presented. Copyright © 2010 John Wiley & Sons, Ltd.
  相似文献   
9.
免疫检测技术是食品安全检测领域中应用广泛的技术之一,新的免疫检测技术不断应用于抗微生物药物残留检验中,有力地推动了抗微生物药物残留安全监测体系的建立。首先,对抗微生物药物人工抗原合成与抗体生产技术进行了论述,之后着重综述了量子点荧光免疫分析法、时间分辨免疫分析法、免疫传感器和免疫芯片检测技术近年来取得的研究进展,并对这些技术的未来发展进行了展望。  相似文献   
10.
Abstract

This study quantified, across a landscape in Eastern Finland, the influence of administrative land-use and technical land-form constraints on timber production. Spatially explicit data about the nature conservation areas, land use plans and steep slopes were integrated with Multi-source National Forest Inventory (MS-NFI) data. The Finnish forestry model MELA was used in the calculations related to updating forest data and estimating different scenarios of timber production with and without constraints. In the study area, the annual volume of maximum sustainable cutting removal defined for the next 30 years was decreased by one-third due to restrictions. The presented approach could be used, for example, to assess timber availability at the landscape level. Future challenges include ensuring the compatibility of spatially explicit data obtained from different sources, identifying the feasibility of forest management operations in the restricted area, and incorporating near-nature forest management operations in the forest planning system in order to estimate the timber production.  相似文献   
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