关键词： Boosted regression tree   Soil fauna effect   Climate   Plant litter quality   Litter decomposition   Biomes  

摘要： Extensive studies have been conducted to evaluate the effect of soil fauna on plant litter decomposition in terrestrial ecosystems. However, scholars have reported inconsistent results on the direction and magnitude of the soil fauna effect. We present a global synthesis of 75 papers that cover 197 plant species with 543 cases of plant litter decomposition experiments and soil fauna effects on plant litter decomposition. By using a boosted regression tree model (BRT), we aim to provide a synthesis of existing data that comprehensively and quantitatively evaluates how climate, plant litter quality, and study methods interact with soil fauna in affecting plant litter decomposition. Global average effect size (ES) is -0.426, which indicates a 35% lower decomposition rate when soil fauna is excluded by physical or chemical exclusion techniques. The final model explains 32.3% of the variation in ES. The predictors that substantially account for the explained variation include mean annual temperature (MAT, 37.1%), mean annual precipitation (MAP, 9.7%), phosphorus (12.4%), nitrogen (5.6%), and lignin content (5.5%). By contrast, the heterogeneity of the study duration and soil fauna exclusion technique have negligible contributions (each <5%). Log effect size strongly decreases with both MAT and MAP. Plant litters with high quality have stronger soil fauna effect because the log effect size is negatively related to nitrogen and phosphorus content and positively related to lignin content. Our analysis demonstrates the critical role of climate and plant litter quality in determining the soil fauna effect on plant litter decomposition in terrestrial ecosystems. However, the large unexplained variation (67.7%) in ES in the BRT model indicates undiscovered mechanisms underlying the soil fauna effect in our analysis. We call for further studies on this topic in the future. (c) 2015 Elsevier Ltd. All rights reserved.

关键词： herbivore exclosures   mesic   plant defenses   semi-arid   trade-off  

摘要： Five sets of herbivore exclosures situated in mesic and semi-arid savannas in Hluhluwe-iMfolozi Park, South Africa were used to investigate the effects of mammal browsers and savanna type on plant traits relating to leaf nutrient content, defense, and growth in seven Acacia species. Mostly, browsing did not significantly affect leaf nutrient content but for a few species (i.e., increasing foliar N and P, decreasing C/N, and total polyphenols). Browser effects on structural defenses tended to be more pronounced than for leaf nutrient content and chemical defenses, particularly for semi-arid species, resulting in longer, thicker, and denser spines, and a lower bite size index on browsed plants for most semi-arid species. Browsing had no significant effect on growth rates for all species. Secondly, we investigated the effect of savanna type (mesic vs. semi-arid) on the same set of plant traits and growth rates. A trade-off in defense strategy was evident where mesic species had lower quality leaves and invested more heavily in growth and chemical defenses, while semi-arid species generally had higher nutrient content leaves and invested more in structural defenses and higher levels of ramification. These findings suggest that the previously documented trade-off in plant growth, resprouting ability and architecture between herbivore versus fire-adapted savanna woody species can possibly be extended to include browse quality and defense type.

关键词： biodiversity   insects, phytophagous   natural enemies and pollinators  

摘要： Our aim was to assess the seasonal abundance and diversity of arthropods on Acacia mangium Willd. (Fabales: Fabaceae) trees. Phytophagous arthropods, natural enemies and pollinators were quantified biweekly in 20 trees during 3 years. The Shannon biodiversity index (H') of arthropods was greater in the summer and smaller in the winter and spring on A. magium. The diversities of species and abundances of individuals of all arthropod taxa were greater in the autumn and smaller in the winter and in the spring. The H' index of arthropods was greater in 2005 and smaller in 2007. The diversity of species and abundance of individuals of phytophagous taxa were greater in 2005 and 2006, respectively, whereas those of natural enemies and pollinators was greater in 2006. Aethalion reticulatum L. (Hemiptera: Aetalionidae) was the most abundant phytophagous species found in the various seasons, while Camponotus sp. 2 (Hymenoptera: Formicidae), Trigona spinipes Fabricius (Hymenoptera: Apidae, Meliponini), Tetragonisca angustula Latreille (Hymenoptera: Meliponinae, Meliponini) and Polistes sp. (Hymenoptera: Vespidae) were the most abundant natural enemies and pollinators. The great diversity of predators on this tree species can explain the little damage to its leaves. These results may be applied to support programs of pest control and maintenance of natural enemies and pollinators in future plantations of A. mangium.

关键词： Pines   Squirrels   Animal behavior   Food   Foraging   Eyes   Predation   Vision  

摘要： Asymmetry in motor patterns is present in a wide variety of animals. Many lateralized behaviors seem to depend on brain asymmetry, as it is the case of different tasks associated to food handling by several bird and mammal species. Here, we analyzed asymmetry in handling behavior of pine cones by red squirrels (Sciurus vulgaris). Red squirrels devote most of their daily activity to feeding, thus this species constitutes an appropriate model for studying asymmetry in food processing. We aimed to explore 1) the potential lateralization in handling of pine cones by squirrels, 2) the dominant pattern for this behavior (left- vs. right-handed), and 3) whether this pattern varies among populations and depending on the pine tree species available. Results revealed that red squirrels handle pine cones in an asymmetrical way, and that direction of asymmetry varies among populations and seems to be determined more by local influences rather than by the pine tree species.

关键词： 实验动物   组织工程   树鼩   二抗   交叉反应   国家自然科学基金  

摘要： 背景:由于树鼩是介于食虫目和灵长目之间的代表,进化程度高,较价廉的灵长类动物,医学生物学的用途很高,已受到广大学者的重视。目的:检测通常用的二抗能否与树鼩的血清发生免疫反应。方法:用Western和ELISA的方法检测树鼩的血清是否与抗兔、抗羊、抗人、抗小鼠、抗大鼠、抗猴的二抗发生交叉反应。结果与结论:Western结果表明树鼩的血清与抗兔、抗羊、抗人、抗小鼠、抗大鼠的二抗均不发生反应,与抗猴的二抗有交叉反应。ELISA的结果也表明树鼩的血清与抗猴的二抗有交叉反应,而与其他二抗没有交叉反应。结果说明通常卖的二抗不能用于树鼩IgG的免疫检测,只有抗猴的二抗与树鼩的血清发生交叉反应,必需制备抗树鼩IgG的单克隆和多克隆抗体,在没有现成抗体可用时,可采用抗猴的二抗替代检测,能在树鼩疾病动物模型的研究中得到广泛应用。

关键词： constraint   development   Ebiscothyris bellonensis gen. et sp nov.   homoplasy   molecular phylogeny   molecular systematics   morphological systematics   new genera   phylogenetic systematics   rRNA  

摘要： We present five case studies among articulate (rhynchonelliform) brachiopods, i.e. of Rhynchonellida, Cancellothyridoidea, Terebratuloidea, Dyscolioidea, Laqueoidea, and various terebratulids with modified long-loops, in an attempt to illustrate and better understand congruence and conflict between morpho-classification and rDNA-based molecular clade structure, having been prompted to address these issues by difficulties encountered when describing the newly collected brachiopod, Ebiscothyris ***. The five studies reveal dramatic conflict in the Rhynchonellida and Terebratuloidea/Dyscolioidea, good congruence in the Cancellothyridoidea and Laqueoidea, and fair congruence (albeit with weak phylogenetic signal) in the long-looped terebratulids. We suggest that the leading cause of the observed conflict lies in the use of inadequately specific morphological characters and morpho-classification. Phylogenetic systematic (cladistic) analyses of Rhynchonellida also conflict markedly with the rDNA gene tree, leading us to recognize that such analyses are not only conceptually circular (using morphological characters to assess a morphological classification) but also to propose that they are biased by the act of classification that necessarily precedes the identification of putatively homologous characters;when the prior classification does not reflect evolutionary history, phylogenetic analysis will do likewise. In addition, we propose that the brachiopod community has overlooked the significance of two sources of morphological homoplasy affecting brachiopod systematics: (1) the loss of co-adapted genomic complexes caused by mass extinctions at the end of the Permian;and (2) the pervasive consequences of developmental integration and constraint resulting from the integrated roles of the outer mantle epithelium in shell deposition and growth that underly the determination of form and the shell-based classification.(c) 2015 The Linnean Society of London

关键词： Herbivorous animal   Ion PGM sequencer   Poisonous tree   SSR   Tree expansion  

摘要： Pieris japonica is a poisonous tree species that is rarely eaten by herbivorous animals, which could allow it to expand its distribution and change ecosystems. Using a next-generation sequencer, 18 microsatellite markers were isolated from P. japonica and characterized. The number of alleles at each locus ranged from 2 to 11. The observed and expected heterozygosities ranged from 0.13 to 1.00 and 0.32 to 0.88, respectively. These markers will be useful for genetic studies of P. japonica, which will be essential for conservation of its surrounding environment.

关键词： competition   forest management   herbivores   invasion ecology   native-non-native interactions   species interactions   tree seedlings  

摘要： Invasive plants, herbivores and site management history can play crucial roles in determining plant community composition. The net effects of invasive species on plant communities are well known, but we have a poor understanding of the relative contributions of direct competitive effects of invasive species and their interactions with herbivores and management practices. Understanding interactions among plant invasions, herbivores and management history is critical for predicting and managing long-term ecological effects of invasions on native communities. We investigated the effects of the invasive annual grass Microstegium vimineum, vertebrate herbivory, site management history and their interactions on seedling performance of five native tree species in six forest sites. Half of the sites had been subjected to recent timber harvesting, and half had not been managed for timber for at least 20years. We evaluated tree seedling survival and biomass after two growing seasons in blocked split-plots where the invasive grass was present or experimentally removed and where vertebrate herbivores were excluded by fencing or allowed onto the plots. Removal of the invasive grass and herbivore exclosures both had positive effects on seedling survival. Survival of all species was significantly increased by removal or by the interaction of removal with exclosure or timber harvest history. There was a significant interaction between exclosure and removal on seedling biomass where seedlings were larger in exclosure treatments with the invasive removed but smaller in exclosure treatments when the invader was present. Mean seedling biomass was 796% greater in harvested sites than in non-harvested sites. The significant positive effects of removal and recent timber harvest on the biomass of two Quercus species suggest strong impacts of invasion and management history on this important *** and applications. An invasive grass directly inhibited tree seedling performance but

关键词： Constrained constructive optimization   Hepatic portal vein   Hepatic vein  

摘要： Physiologically realistic geometric models of the vasculature in the liver are indispensable for modelling hepatic blood flow, the main connection between the liver and the organism. Current in vivo imaging techniques do not provide sufficiently detailed vascular trees for many simulation applications, so it is necessary to use algorithmic refinement methods. The method of Constrained Constructive Optimization (CCO) (Schreiner et al., 2006) is well suited for this purpose. Its results after calibration have been previously compared to experimentally acquired human vascular trees (Schwen and Preusser, 2012). The goal of this paper is to extend this calibration to the case of rodents (mice and rats), the most commonly used animal models in liver research. Based on in vivo and ex vivo micro-CT scans of rodent livers and their vasculature, we performed an analysis of various geometric features of the vascular trees. Starting from pruned versions of the original vascular trees, we applied the CCO procedure and compared these algorithmic results to the original vascular trees using a suitable similarity measure. The calibration of the postprocessing improved the algorithmic results compared to those obtained using standard CCO. In terms of angular features, the average similarity increased from 027 to 0.61, improving the total similarity from 028 to 0.40. Finally, we applied the calibrated algorithm to refine measured vascular trees to the (higher) level of detail desired for specific applications. Having successfully adapted the CCO algorithm to the rodent model organism, the resulting individual-specific refined hepatic vascular trees can now be used for advanced modeling involving, e.g., detailed blood flow simulations. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： 树鼩   等效剂量   换算系数   体表面积  

摘要： 目的:测算树鼩与人类及其它实验动物等效剂量换算系数,为树鼩在生物医学领域的广泛应用提供重要的基础数据。方法:Image J软件测算树鼩表皮面积;基于体质量和体表面积,求出树鼩在Meeh-Rubner氏公式中的K值;计算得出树鼩与人类及其它种类实验动物之间药物剂量换算的常用系数。结果:树鼩在Meeh-Rubner氏公式中的K值为10.83±1.73;mg/kg-mg/m2转移因子为4.77±1.02;单位体质量上体表面积相对比值为0.65±0.10;按体质量/体表面积折算等效剂量的系数中,人类剂量(70kg)至树鼩剂量(130g)的换算系数为8.29。结论:本研究的结果为树鼩常用基础数据的完善提供了重要内容。