Isolation,characterization and evaluation of 11 autosomal STRs suitable for population studies in black and gold howler monkeys Alouatta caraya

We identified 11 polymorphic microsatellite markers for Alouatta caraya. Three markers were isolated from an enriched genomic library of A. caraya (AC14, AC17, AC45), five were previously described in Homo sapiens (TGMS1, TGMS2, D5S117, D8S165, D17S804), and three were identified for Lagothix lagotricha (1110, 1118, 157). Forty‐eight individuals from one Argentinean population were genotyped, yielding heterozygosity values between 0.146 and 0.792. These markers provide an exclusion power of 0.922 when neither parent is known (0.992 when one parent is known) and are suitable for parentage analysis, population genetics and phylogeographical studies of A. caraya, the southernmost primate in the New World.     

Traditional Versus Multivariate Methods for Identifying Jaguar,Puma, and Large Canid Tracks

ABSTRACT The jaguar (Panthera onca) and puma (Puma concolor) are the largest felids of the American Continent and live in sympatry along most of their distribution. Their tracks are frequently used for research and management purposes, but tracks are difficult to distinguish from each other and can be confused with those of big canids. We used tracks from pumas, jaguars, large dogs, and maned wolves (Chrysocyon brachyurus) to evaluate traditional qualitative and quantitative identification methods and to elaborate multivariate methods to differentiate big canids versus big felids and puma versus jaguar tracks (n = 167 tracks from 18 zoos). We tested accuracy of qualitative classification through an identification exercise with field-experienced volunteers. Qualitative methods were useful but there was high variability in accuracy of track identification. Most of the traditional quantitative methods showed an elevated percentage of misclassified tracks (≥20%). We used stepwise discriminant function analysis to develop 3 discriminant models: 1 for big canid versus big felid track identification and 2 alternative models for jaguar versus puma track differentiation using 1) best discriminant variables, and 2) size-independent variables. These models had high classification performance, with <10% of error in the validation procedures. We used simpler discriminant models in the elaboration of identification keys to facilitate track classification process. We developed an accurate method for track identification, capable of distinguishing between big felids (puma and jaguar) and large canids (dog and maned wolf) tracks and between jaguar and puma tracks. Application of our method will allow a more reliable use of tracks in puma and jaguar research and it will help managers using tracks as indicators of these felids' presence for conservation or management purposes.     

模拟地表火行为对燃烧剩余物水溶性碳氮的影响

燃烧剩余物是火烧迹地土壤表面必然存在的残留物,可以通过降水过程以及地表径流释放其所含有的矿物质和有机质至土壤生态系统,从而在一定时间内持续地对火后生态系统恢复过程造成影响。但不同火行为下,相同的可燃物所产生的燃烧剩余物可能具有不同的生态学功能,为了认知火行为对燃烧剩余物的影响,进一步了解二者对火烧迹地生态恢复过程中养分循环和能量流动的潜在影响,探究了火行为对燃烧剩余物水溶性碳氮化学计量特征的影响。以红松人工林地表可燃物为实验材料,通过设置不同坡度和含水率为火行为的驱动因子,进行了森林可燃物床层地表上坡火和下坡火的室内模拟燃烧实验。用独立样本T检验、单因素方差分析、多因素方差分析探究了火环境对燃烧剩余物水溶性碳氮和火行为的影响,用基于距离的冗余分析(db-RDA)探究了火行为对燃烧剩余物水溶性碳氮化学计量特征的影响。上坡火实验组的燃烧剩余物水溶性碳氮含量明显高于下坡火实验组(P<0.01);5°实验组中,燃烧剩余物的水溶性碳含量随着可燃物预设含水率的升高而升高(P<0.05)。进一步的数据分析发现火行为与燃烧剩余物水溶性碳氮化学计量特征关系密切,火焰宽度是影响燃烧剩余物水溶性...     

油橄榄果渣抗氧化部位化学成分的研究北大核心CSCD

为了开展油橄榄果渣中主要抗氧化活性成分的研究,该文通过1,1-二苯基-2-苦肼基自由基(DPPH·)法测定了油橄榄果渣不同提取部位清除DPPH·的能力,并采用硅胶、ODS、Sephadex LH-20等柱色谱方法对抗氧化活性部位的化合物进行分离,同时运用核磁共振波谱等方法鉴定了化合物的结构。结果表明:(1)油橄榄果渣的乙酸乙酯部位具有显著的抗氧化活性,其清除DPPH·的半数抑制浓度(IC_(50))为119.11μg·mL^(-1)。(2)从该活性部位分离得到17个化合物,分别鉴定为没食子酸(1)、羟基酪醇(2)、原儿茶酸(3)、酪醇(4)、儿茶素(5)、香草酸(6)、咖啡酸(7)、香草醛(8)、丁香酸(9)、木犀草苷(10)、橄榄苦苷(11)、丁香酚(12)、槲皮素(13)、木犀草素(14)、芦丁(15)、山楂酸(16)、齐墩果酸(17)。其中,化合物1、6、7、9、15为首次从油橄榄果渣中分离得到。该研究明确了油橄榄果渣的抗氧化物质基础,为油橄榄果渣进一步的高值化利用提供了科学依据。     

Photosynthetic limitations and volatile and non‐volatile isoprenoids in the poikilochlorophyllous resurrection plant Xerophyta humilis during dehydration and rehydration

We investigated the photosynthetic limitations occurring during dehydration and rehydration of Xerophyta humilis, a poikilochlorophyllous resurrection plant, and whether volatile and non‐volatile isoprenoids might be involved in desiccation tolerance. Photosynthesis declined rapidly after dehydration below 85% relative water content (RWC). Raising intercellular CO₂ concentrations during desiccation suggest that the main photosynthetic limitation was photochemical, affecting energy‐dependent RuBP regeneration. Imaging fluorescence confirmed that both the number of photosystem II (PSII) functional reaction centres and their efficiency were impaired under progressive dehydration, and revealed the occurrence of heterogeneous photosynthesis during desiccation, being the basal leaf area more resistant to the stress. Full recovery in photosynthetic parameters occurred on rehydration, confirming that photosynthetic limitations were fully reversible and that no permanent damage occurred. During desiccation, zeaxanthin and lutein increased only when photosynthesis had ceased, implying that these isoprenoids do not directly scavenge reactive oxygen species, but rather protect photosynthetic membranes from damage and consequent denaturation. X. humilis was found to emit isoprene, a volatile isoprenoid that acts as a membrane strengthener in plants. Isoprene emission was stimulated by drought and peaked at 80% RWC. We surmise that isoprene and non‐volatile isoprenoids cooperate in reducing membrane damage in X. humilis, isoprene being effective when desiccation is moderate while non‐volatile isoprenoids operate when water deficit is more extreme.     

Remote sensing of larch phenological cycle and analysis of relationships with climate in the Alpine region

This research aims at developing a remote sensing technique for monitoring the interannual variability of the European larch phenological cycle in the Alpine region of Aosta Valley (Northern Italy) and to evaluate its relationships with climatic factors. Phenological field observations were conducted in eight test sites from 2005 to 2007 to determine the dates of completion of different phenological phases. MODerate Resolution Imaging Spectrometer (MODIS) 250 m 16‐days normalized difference vegetation index (NDVI) time series were fitted with double logistic curves and the dates corresponding to different features of the curves were determined. Comparison with field data showed that the features of the fitted NDVI curve that allowed the best estimate of the start and end of the growing season were the zeroes of its third derivative (MAE of 6 and 4 days, respectively). The start and end of season were also estimated with the spring warming (SW) and growing season index (GSI) phenological models. MODIS start and end of season dates generally agreed with those obtained by the SW and GSI climate‐driven phenological models. However, phenological models provided erroneous results when applied in years with anomalous meteorological conditions. The relationships between interannual variability of the larch phenological cycle and climate were investigated by comparing the mean start and end of season yearly anomalies with air temperature anomalies. A strong linear relationship (R²=0.91) was found between mean spring temperatures and mean start of season dates, with an increase of 1 °C in mean spring temperature leading to a 7‐day anticipation of mean larch bud‐burst date. Leaf coloring dates were found to be best related with mean September temperature (R²=0.77), but with higher spring temperatures appearing to lead to earlier leaf coloring.     

Habitat selection by the swamp wallaby (Wallabia bicolor) in relation to diel period,food and shelter

Patterns of resource selection by animals may be influenced by sex, and often change over a 24‐h period. We used a dry sclerophyll landscape managed for commercial timber production to investigate the effects of sex and diel period on habitat selection by the swamp wallaby (Wallabia bicolor). We predicted that selection would be (i) affected by both sex and diel period; and (ii) positively related to lateral cover during the day, but to food resources at night. Non‐metric multidimentional scaling indicated that some of the available habitats differed markedly with respect to visibility (an indicator of lateral cover), fern cover, forb cover, wallaby density and a forage quality index, providing the basis for non‐random habitat selection. At the landscape scale, wallabies showed strong selection for 5‐year‐old regenerating sites, selected against 10‐year‐old regenerating sites and unharvested forest, and avoided recently harvested (3–10 months post‐harvest) sites completely. At the scale of individual home ranges, a pooled male and female sample demonstrated selection for unharvested forest over recently harvested sites during both diurnal and nocturnal periods. A separate analysis showed that both sex and diel period influenced the selection of 5‐ and 10‐year‐old sites and the surrounding unharvested forest. Using a novel approach, we demonstrated that diurnal habitat selection by both sexes was negatively correlated with visibility, representing stronger selection for areas with more lateral cover. Nocturnal selection by females was positively correlated with values of a forage quality index, but this was not the case for males. We hypothesise that the observed patterns of selection were driven by the need to find food and avoid predators, but were also affected by the different reproductive strategies of males and females. Our results demonstrate the importance of incorporating factors such as sex and diel period into analyses of habitat selection.