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131.
Joseph D. Clark 《Population Ecology》2019,61(1):93-101
Spatially explicit capture–recapture methods do not assume that animals have equal access to sampling devices (e.g., detectors), which allows for gaps in the sampling extent and nonuniform (e.g., clustered) sampling designs. However, the performance (i.e., relative root mean squared error [RRMSE], confidence interval coverage, relative bias and relative standard error) of clustered detector arrays has not been thoroughly evaluated. I used simulations to evaluate the performance of various detector and cluster spacings, cluster configurations (i.e., number of detectors arranged in a square grid), sampling extents and number of sampling occasions for estimating population density, the relationship between detection rate and distance to a detector from the animal's center of activity (σ) and base detection rates, using American black bears (Ursus americanus) as a case study. My simulations indicated that a wide range of detector configurations can provide reliable estimates if spacing between detectors in clusters is ≥1σ and ≤3σ. A number of cluster configurations and occasion lengths produced estimates that were unbiased, resulted in good spatial coverage, and were relatively precise. Moreover, increasing the duration of sampling, establishing large study areas, increasing detection rates and spacing clusters so that cross-cluster sampling of individuals can occur could help ameliorate deficiencies in the detector layout. These results have application for a wide array of species and sampling methods (e.g., DNA sampling, camera trapping, mark-resight and search-encounter) and suggest that clustered sampling can significantly reduce the effort necessary to provide reliable estimates of population density across large spatial extents that previously would have been infeasible with nonclustered sampling designs. 相似文献
132.
成簇的规律间隔性短回文序列(CRISPR)基因编辑系统,因其设计简单操作方便和无种属限制,已成为一种广泛应用的基因组定点编辑工具,在复杂的基因组编辑,例如基因的人源化改造以及条件等位基因的构建中有所应用。在自然界中,CRISPR系统拥有多种类别。其中,CRISPR/Cas9系统是研究最深入、应用最成熟的一种。本文针对CRISPR/Cas9系统,分别从基因敲入/敲除片段的大小、同源臂长短、构型即递送方式等技术环节进行综述,阐述不同设计及操作条件下由CRISPR/Cas9系统介导的基因敲入/敲除的效率差异。 相似文献
133.
Grant Evans’ body of work on Laos consistently sought to understand how peasant society responded to political, social and economic change. As the Lao peasantry became ever more integrated both nationally and within the wider Southeast Asian region, and relations of market exchange came to dominate rural life, Evans maintained the need to reflect on Laos’ peasant roots to understand resulting pathways of agrarian change. This paper reconnects with this discussion in the contemporary Lao context, focusing on three dimensions of mobility: the widening spatial and sectoral ‘footprints’ of rural livelihoods; physical movement within and beyond rural settings in Laos; and reflections on issues of differentiation. We first track the political and policy changes that have most strongly influenced rural life since Evans’ early research on collectivisation, before exploring ways in which spatial integration, subsistence‐to‐commercial transition and migration have situated the remnants of Lao peasant society in a world of flows. 相似文献
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135.
全球气候变暖是人类面临最严峻的环境挑战。有效控制碳排放, 充分发挥生态系统的固碳能力是实现碳中和目标的重要手段。作为碳封存能力最强的一种湿地类型, 泥炭地是加快实现碳中和目标的关键陆地生态系统。作为泥炭地“有效的生态系统工程师”, 泥炭藓(Sphagnum)在泥炭地的碳汇功能、过滤淡水及保护土地免受洪水侵袭等方面具有极其重要的作用。100多年来, 泥炭藓广泛应用于医药保健、污染监测和废水处理等领域, 尤其是作为一类最值得信赖的土壤介质和保湿材料一直被广泛用于园艺产业。在全球气候变暖和“双碳”目标的大背景下, 泥炭藓已经成为生命科学和生态学研究的热点。该文主要从泥炭藓的形态、物种多样性和起源、生境与分布、繁殖和保护、培养与种植、环境指示和监测、用途和应用, 以及碳封存、储水和酸化能力等方面进行综述, 旨在为泥炭藓研究、泥炭地的保护和恢复以及泥炭藓开发利用和产业发展提供借鉴与参考。 相似文献
136.
Glycomics-driven discoveries in schistosome research 总被引:2,自引:0,他引:2
Schistosome glycans and glycoconjugates play a prominent role in the parasite's biology, in particular in the interaction with the human host. A large amount of structural data regarding glycosylation of different schistosome life stages and glycoconjugate subsets has been collected in the last decade, but many significant gaps in our knowledge of the schistosomal glycome remain. Here we will present a concise review of the already available data guided by a selection of recently generated stage-specific glycan profiles, and discuss implications and prospects of glycomics studies of schistosomes. 相似文献
137.
Hiroyuki Nakamura Jong-Dae Lee Manabu Ueno Yusuke Miyajima Hyun Seung Ban 《NanoBioTechnology》2007,3(2):135-145
High accumulation and selective delivery of boron into tumor tissues are the most important requirements to achieve efficient
neutron capture therapy of cancers. We focused on liposomal boron delivery system to achieve a large amount of boron delivery
to tumor. We succeeded in the synthesis of the double-tailed boron cluster lipids 4a–c and 5a–c, which has a B12H11S-moiety as a hydrophilic function, by S-alkylation of B12H11SH with bromoacetyl and chloroacetocarbamate derivatives of diacylglycerols. Size distribution of liposomes prepared from
the boron cluster lipid 4b, dimyristoylphosphatidylcholine, polyethyleneglycol-conjugated distearoylphosphatidylethanolamine, and cholesterol was determined
as 100 nm in diameter by an electrophoretic light scattering spectrophotometer. Calcein-encapsulation experiments revealed
that these boronated liposomes are stable at 37 °C in fetal bovine serum solution for 24 h. 相似文献
138.
139.
本文通过对郑州青台遗址新石器时代中晚期91例个体、1913枚牙齿罹患龋齿的统计与分析可知,青台人群患龋率为71.43%,龋齿率为13.38%。其中,龋齿率女性高于男性,可能与女性孕期生理变化、食物选择及性别分工等有关。上颌龋齿率高于下颌,臼齿及咬合面为龋齿易患齿类及部位。通过对比可知青台人群显示出较高的龋齿罹患率,暗示该人群饮食中应包含较多的碳水化合物类食物,这可能与新石器时代中晚期黄河中游发达的旱作农业有关。此外,龋齿率在黄河及长江中、下游新石器时代农业人群中的区域性差异可能与龋病病因的复杂性和各地区不同的文化面貌、人群生活方式有关。 相似文献
140.