Disentangling spatial,environmental and historical effects on tropical forest tree species turnover

空间、环境和历史因素对热带森林树种周转的影响 本文通过回答以下问题来分析空间距离、当前和过去的环境差异及这几个因素对树木群落分类和系统发育转换的影响：(i)树木群落分类和系统发育转换是否与空间距离通过环境差异产生的间接影响相关？(ii)树木群落分类和系统发育转换是否随古气候(末次盛冰期和中全新世)的变化而变化？本文对巴西的14个大西洋雨林样点(采样面积20.4 ha) 83个科615个种进行了研究，获得了当前、中全新世和末次盛冰 期的地块地理坐标、土壤变量和样点生物气候变量。我们使用基于距离的结构方程模型(SEM)来(i)检测空间距离和环境差异的直接影响，以及(ii)检测空间距离通过环境差异对分类(Bray-Curtis距离)和系统发育转换(Comdist和Comdistnt距离)的间接影响。研究结果表明，空间距离通过环境差异对分类和系统发育转换的间接影响较弱。基于生态位中性的历史过程带来的直接影响驱动了树木群落的转换。因此，我们推断古气候(历史过程)促进了产生当前植物区系分支的选择，而空间距离(中性的过程)限制了物种从区域种库向外扩散的范围，环境条件(基于生态位的过程)则在本地选择能够持续生存的分类群。     

A Spotlight on Sporothrix and Sporotrichosis

Mycopathologia - Sporothrix (order Ophiostomatales) comprises a genus with 53 species, of which S. brasiliensis, S. schenckii, S. globosa, and S. luriei cause skin infections in humans and other...     

Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC –UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference)<UHPLC-UV<OLE-UHPLC-UV. Zebrafish assay results showed that 70 % EtOH extract of V. Curassavica leaves exhibited lower toxicity compared to 100 % EtOH extract, with LC₅₀ of 164.3 and 122.9 μg/mL, respectively, in 24 h post fertilization. Some embryos exhibited malformation phenotypes in the heart, somites, and eyes, mainly in higher extract concentrations. Extracts and brickellin exhibited higher antioxidant activity in the DPPH⋅ assay, while brickellin+artemetin displayed higher antioxidant activity compared to the extracts and isolated flavones in the O₂⋅⁻ and HOCl/OCl⁻ scavenging assays. Cordialin A and brickellin exhibited low COX-1, COX-2, and phospholipase A₂ inhibition.     

Estimating predation rates from molecular gut content analysis

Several methods have been published to estimate per capita predation rates from molecular gut content analysis relying on intuitive understanding of predation, but none have been formally derived. We provide a theoretical framework for estimating predation rates to identify an accurate method and lay bare its assumptions. Per capita predation can be estimated by multiplying the prey decay rate and the prey quantity in the predators. This assumes that variation in per capita predation rate is approximately normally distributed, prey decay occurs exponentially, and predation is in steady state. We described several ways to estimate steady state predation, including using only qualitative presence-absence data to estimate the decay rate and in addition, we provided a method for estimating per capita predation rate when predation is not in steady state. We used previously published data on aphid consumption by a ladybird beetle in a feeding trial to calculate the predation rate and compare published methods with this theoretically derived method. The estimated predation rate (3.29 ± 0.27 aphids/h) using our derived method was not significantly different from the actual predation rate, 3.11 aphids/h. In contrast, previously published methods were less accurate, underestimating the predation rate (0.33 ± 0.02 to 1.66 ± 0.8 aphids/h) or overestimating it (3.64 ± 0.30 aphids/h). In summary, we provide methods to estimate predation rates even when variation in predation rates is not exactly normally distributed and not in steady state and demonstrate that the prey decay rate, and not the prey detection period, is required.     

Genetic analysis of a local population of <Emphasis Type="Italic">Oryza glumaepatula</Emphasis> using SSR markers: implications for management and conservation programs

Knowledge of natural diversity and population structures of wild species, which might be related to cultivated species, is fundamental for conservation and breeding purposes. In this study, a genetic characterization of a large population of Oryza glumaepatula, occurring in a 10 km² area located at Tamengo Basin (Paraguay River, Brazil), was performed using SSR markers. This population is annually dragged from the river to permit navigation; one goal of this study was to examine the impact of this removal on genetic variability. From 18 polymorphic SSR markers, a total of 190 alleles were detected in a sample of 126 individuals, with an average of 10.3 alleles/locus, and a H _e of 0.67. The five QTL-related markers showed an average H _e value of 0.56, while the remaining 13 markers detected an average estimate of 0.70. An apparent outcrossing rate of 30%, a high proportion of alleles at low frequencies (56%), and the presence of exclusive alleles (9.5%) were found, with strong evidence of the establishment of individuals from different populations upstream in the Paraguay River. For conservation purposes, the river drag has no effect on the population. However, periodical seed collection from the Corumbá population can preserve part of the genetic variability present in upstream populations reducing the need for upriver collecting expeditions.     

Changes in lymphocyte and neutrophil function induced by a marathon race

The aim of this study was to investigate the changes in lymphocyte and neutrophil selected functions before and after a marathon race. Fifteen professional athletes were recruited, and the following parameters were measured: plasma concentrations of IL‐1ra, IL‐6, IL‐8, IL‐10, TNF‐α and C‐reactive protein (CRP); neutrophil phagocytic capacity; cytokine production by neutrophils and lymphocytes and signs of neutrophil and lymphocyte death. The marathon race had no effect on CRP levels, but plasma concentrations of IL‐6 and IL‐1ra were increased. Although no effect was observed on the production of IL‐6, IL1‐ra, TNF‐α, IL‐1β and IL‐8 by unstimulated or stimulated neutrophils, a decrease in neutrophil phagocytic activity was observed immediately following the marathon. A high percentage of neutrophils undergoing apoptosis was observed due to the intense training regimen, whereas the percentages of apoptotic neutrophils were reduced after the race. The production of IL‐2, TNF‐α, IL‐1β and IL‐10 by lymphocytes was decreased by 50%–80%, and the percentage of apoptotic and necrotic lymphocytes was increased by 42% and fourfold, respectively, as a result of the race. In conclusion, the increase in plasma levels of IL‐6, IL‐8, IL‐1ra and IL‐10 after the race was not due to the production of the cytokines by neutrophils or lymphocytes. In fact, the marathon led to a decrease in lymphocyte and neutrophil function, and the diminished function was more pronounced in lymphocytes, indicating an impairment in acquired immunity. Copyright © 2012 John Wiley & Sons, Ltd.     

The contribution of soil adhesion to radiocaesium uptake by leafy vegetables

The Goiânia accident, Brazil, was used as an opportunity to quantify the contributions of different mechanisms, in particular mass loading, leading to caesium uptake by leafy vegetables in a semi-urban environment contaminated with¹³⁷Cs. Soil splash contributions of 70–90% were quantified for lettuce and 50–60% for green cole. Soil mass loadings of 130 and 340 mg · g^–1 were estimated for lettuce and 120 and 150 mg · g^–1 for green cole. The results call attention to the potential significant contribution of the soil splash to radionuclide uptake by plants which have the edible plant parts near the soil surface (within 30–40 cm) and low root uptake factors. For radiological assessment purposes it could also be necessary to consider the contamination of crops by this mechanism.     

Envelope diversity, characteristics of V3 region and predicted co-receptor usage of human immunodeficiency viruses infecting north indians

Subtypes of human immunodeficiency virus type 1 circulating in 21 north Indian patients were characterized based on the partial sequence of the gp120 envelope protein. A majority of viruses (85.7%, 18/21) were subtype C, while 14.3% (3/21) were subtype A. Sequence analysis revealed that the V3 region was highly conserved compared with V4 and V5. The predicted use of co-receptors indicated exclusive usage of R5, except for two subtype A viruses (AIIMS279 and AIIMS281). Our results demonstrate conservation within the V3 loop of subtype C viruses, and suggest the emergence of non-clade C viruses in the north Indian population.     

Resistance to bacitracin in Streptococcus pyogenes from oropharyngeal colonization and noninvasive infections in Portugal was caused by two clones of distinct virulence genotypes

During 2000–2007 in Lisbon, we identified 45 bacitracin-resistant Streptococcus pyogenes isolates among 1629 isolates: 24 from oropharyngeal healthy carriers (out of 1026), 21 from patients with noninvasive infections (out of 559) and zero from invasive infections (out of 44). Forty-four of those isolates, mainly of colonization, are low-level bacitracin-resistant members of the cMLS_B-macrolide-resistant and tetracycline-susceptible emm 28/ST52 clone previously detected in Europe, but only among clinical samples. One high-level bacitracin-resistant isolate, associated with a tonsillitis/pharyngitis episode, is cMLS_B-macrolide-resistant and tetracycline-resistant member of the emm 74/ST120 lineage, which was not previously known to include bacitracin-resistant isolates. The bcrABDR operon encoding an ATP-binding cassette transporter in Enterococcus faecalis was not detected among these bacitracin-resistant S. pyogenes strains. Virulence profiling indicated that genes coding for exotoxins and superantigens seem to be clone specific. This study provides an increased knowledge about specific bacitracin-resistant S. pyogenes strains, which may be useful in future investigations aiming to understand the mechanism(s) leading to bacitracin resistance and the cause(s) for differences in colonization and/or dissemination potential.