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31.
Ecological processes in food webs depend on species interactions. By identifying broad‐scaled interaction patterns, important information on species' ecological roles may be revealed. Here, we use the group model to examine how spatial resolution and proximity influence group structure. We examine a data set from the Barents Sea, with food webs described for both the whole region and 25 subregions. We test how the group structure in the networks differ comparing (1) the regional metaweb to subregions and (2) subregion to subregion. We find that more than half the species in the metaweb change groups when compared to subregions. Between subregions, networks with similar group structure are spatially related. Interestingly, although species overlap is important for similarity in group structure, there are notable exceptions. Our results highlight that species ecological roles vary depending on fine‐scaled differences in the patterns of interactions, and that local network characteristics are important to consider.  相似文献   
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为发掘甘薯近缘野生种三裂叶薯(Ipomoea triloba)的NBS-LRR类抗病基因,从基因数据库中对三裂叶薯基因组序列进行了筛选、鉴定和分析。结果表明,从三裂叶薯的98 025个基因中,筛选到282个编码NBS-LRR类蛋白的基因,其中N型80个,NL型83个,CN型28个,CNL型57个,TN型10个,TNL型23个,RN型1个。三裂叶薯的16条染色体上均含有NBS-LRR家族基因,数量最多的染色体含有65个,最少的只有1个。三裂叶薯基因组共有55个基因簇,包含了63.5%的NBS-LRR家族基因。在NBS-LRR抗病基因家族中,CNL和TNL亚家族分别对应到7和11个保守结构域。这为三裂叶薯抗性资源的利用提供了科学参考。  相似文献   
34.
Thresholds for the detection of changes in temperature are used to indicate neuropathy, but a variety of different contact areas and contact locations are used. This study was designed to determine the effects of variations in contact area and contact location on both warm and cool thresholds at the fingertip. With 20 healthy subjects (10 females and 10 males aged 20–30 years), warm thresholds and cool thresholds were determined in two separate sessions using the method of limits. In the first part of each session, thresholds were determined around the centre of the whorl using circular contactors with five different diameters (3, 6, 9, 12, and 55 mm). In the second part of each session, thresholds were determined using two contactors (6- and 12-mm diameter) at three locations along the fingertip: (i) distal (5 mm from the nail), (ii) middle (centre of whorl), and (iii) proximal (3 mm from the distal interphalangeal joint). With increasing contact area, the warm thresholds decreased, the cool thresholds increased, and the inter-subject variability in both warm and cool thresholds decreased. Using the 6-mm diameter contactor, warm thresholds were independent of location but cool thresholds increased from distal to proximal locations. It is concluded that temperature sensitivity at the fingertip increases with increasing area of contact, with the variability in thresholds consistent with the existence of warm and cool “insensitive fields”. The findings show that the influence of contact area and contact location should be considered when assessing thermotactile thresholds at the fingertip.  相似文献   
35.
Abstract

Using diffusion tensor tractography, we investigated the anatomical location of medial lemniscus (ML) and spinothalamic tract (STT) at pons. We recruited 47 healthy volunteers. Evaluation of the anatomical location of ML and STT was performed using the highest probabilistic location at the upper, middle, and lower pons. According to findings, MLs were located around the middle to medial one-third, between midline and lateral boundary of pons in the pontine tegmentum and STTs were located posterolaterally to ML.  相似文献   
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When organisms perform a single task, selection leads to phenotypes that maximize performance at that task. When organisms need to perform multiple tasks, a trade‐off arises because no phenotype can optimize all tasks. Recent work addressed this question, and assumed that the performance at each task decays with distance in trait space from the best phenotype at that task. Under this assumption, the best‐fitness solutions (termed the Pareto front) lie on simple low‐dimensional shapes in trait space: line segments, triangles and other polygons. The vertices of these polygons are specialists at a single task. Here, we generalize this finding, by considering performance functions of general form, not necessarily functions that decay monotonically with distance from their peak. We find that, except for performance functions with highly eccentric contours, simple shapes in phenotype space are still found, but with mildly curving edges instead of straight ones. In a wide range of systems, complex data on multiple quantitative traits, which might be expected to fill a high‐dimensional phenotype space, is predicted instead to collapse onto low‐dimensional shapes; phenotypes near the vertices of these shapes are predicted to be specialists, and can thus suggest which tasks may be at play.  相似文献   
38.
炭角菌科部分类群的生物地理学研究(英文)   总被引:1,自引:0,他引:1  
与肉质真菌相比,大多数炭角菌科真菌的子实体结构和质地使其在自然环境中保持长久,不易腐变,这有利于记录该科采集物的分布信息,基于过去长达25年对该科的深厚工作积累,使我们有可能对其进行地理分布的研究。  相似文献   
39.
This paper establishes the nucleus,cytoplasm,cell membrane and extracellular four database based on the protein subcellular localization,and uses the IDQD method to predict the subcellular localization of the four libraries.  相似文献   
40.
Previous studies have shown that switchgrass has a wide range of genetic variation and that productivity is linked to local adaptation to the location of origin for many cultivars. In this meta‐analysis, we compiled and analyzed 900 observations associated with 41 field trials for four switchgrass cultivars (two lowlands, Alamo and Kanlow, and two uplands, Cave‐In‐Rock and Shelter). This extensive dataset and machine learning were used to identify the most influential variables impacting switchgrass productivity, to search for evidence of local adaptation to each cultivar's location of origin, and to predict change in productivity under future climate for each cultivar. In general, variables associated with climate and management are more important predictors of productivity relative to soil variables. Three climatic variables, annual mean temperature, annual precipitation, and precipitation in the wettest month, are identified as key environmental variables for productivity of all cultivars. Productivity under future climate (2041–2060) is predicted to stay stable for all cultivars relative to the prediction under current climate (1986–2005) across all trial locations and over a 20‐year simulation period. However, the productivity of each cultivar varies from location to location and from year to year, although productivity varies more between locations than between years. Additionally, we observe shifts in the most productive cultivar at the local field scale depending on the combination of management practice and climates. The shape of the relationship between productivity and the annual mean temperature relative to the cultivar's location of origin is a bell‐shaped curve for Kanlow, Cave‐in‐Rock, and Shelter, indicative of local adaptation. Identifying influential environmental variables and their relationships to productivity with respect to cultivar's location of origin help predicting productivity on the local field scale, and will help with the biofuel production planning through the selection of suitable cultivars for different locations under climate changes.  相似文献   
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