Bigger testes increase paternity in a simultaneous hermaphrodite,independently of the sperm competition level

Hermaphroditic animals face the fundamental evolutionary optimization problem of allocating their resources to their male vs. female reproductive function (e.g. testes and sperm vs. ovaries and eggs), and this optimal sex allocation can be affected by both pre‐ and post‐copulatory sexual selection. For example, local sperm competition (LSC) – the competition between related sperm for the fertilization of a partner's ova – occurs in small mating groups and can favour a female‐biased sex allocation, because, under LSC, investment into sperm production is predicted to show diminishing fitness returns. Here, we test whether higher testis investment increases an individual's paternity success under sperm competition, and whether the strength of this effect diminishes when LSC is stronger, as predicted by sex allocation theory. We created two subsets of individuals of the simultaneously hermaphroditic flatworm Macrostomum lignano – by sampling worms from either the highest or lowest quartile of the testis investment distribution – and estimated their paternity success in group sizes of either three (strong LSC) or eight individuals (weak LSC). Specifically, using transgenic focal individuals expressing a dominant green‐fluorescent protein marker, we showed that worms with high testis investment sired 22% more offspring relative to those with low investment, corroborating previous findings in M. lignano and other species. However, the strength of this effect was not significantly modulated by the experienced group size, contrasting theoretical expectations of more strongly diminishing fitness returns under strong LSC. We discuss the possible implications for the evolutionary maintenance of hermaphroditism in M. lignano.     

昆虫发育进度的非正态描述──分段指数曲线

提出了分段连续指数曲线转化为多元线性回归方程的方法。利用取剩余平方和最小的方法确定未知折点。给出了在描述昆虫发育进度的模拟模型。     

Determination of synergistic effects of antibiotics and Zno NPs against isolated E. Coli and A. Baumannii bacterial strains from clinical samples

The mortality rates has been increased globally due to multidrug resistant (MDR) E.coli and A.baumanii bacterial strains and also there is an emerging resistance of the Enterobacteriaceae family of bacteria to Carbapenem antibiotics (CRE) in Saudi Arabia. The main aim of our research study is to isolate E.coli and A. baumannii bacterial species from various collected clinical samples and to evaluate the MIC and FICI of Colistin, Ciprofloxacin, Meropenem and ZnO NPs and in combination of Colistin, Ciprofloxacin, Meropenem with ZnO NPs.The clinical isolated strains of A. baumannii (MRO-17-13) and A. baumannii (MRO-17–25) was found to be sensitive towards colistin with 0.5 μg/mL concentration, whereas, all the isolated A. baumannii strains showed similar MIC value 2 mg/mL when tested with ZnO NPs, the MIC value for the ZnO NPs was found to be similar for all the E.coli strains 0.25 mg/mL. The effects of all Ciprofloxacin concentrations used in the study were bacteriostatic against E. coli (01UR19006568-01) strain but 1 mg/mL concentration of ZnO NPs alone is showed bactericidal activity, ZnO NPs effect was found to be concentration dependent, as highest concentration of ZnO NPs showed strongest antibacterial effect. In conclusion, more investigation is required to evaluate the acceptable concentration of Zno NPs and antibiotics selected to avoid toxicity and must be tested against more clinically isolated gram-negative bacterial strains.     

Synthesis and profiling of benzylmorpholine 1,2,4,5-tetraoxane analogue N205: Towards tetraoxane scaffolds with potential for single dose cure of malaria

A series of aryl carboxamide and benzylamino dispiro 1,2,4,5-tetraoxane analogues have been designed and synthesized in a short synthetic sequence from readily available starting materials. From this series of endoperoxides, molecules with in vitro IC50s versus Plasmodium falciparum (3D7) as low as 0.84?nM were identified. Based on an assessment of blood stability and in vitro microsomal stability, N205 (10a) was selected for rodent pharmacokinetic and in vivo antimalarial efficacy studies in the mouse Plasmodium berghei and Plasmodium falciparum Pf3D70087/N9 severe combined immunodeficiency (SCID) mouse models. The results indicate that the 4-benzylamino derivatives have excellent profiles with a representative of this series, N205, an excellent starting point for further lead optimization studies.     

哺乳动物存活曲线类型的分析方法探讨

动物的存活曲线通常可分为3种类型：凸型（Ⅰ型或A型）、直线型（Ⅱ型或B型）和凹型（Ⅲ型或C型）。存活率曲线与存活曲线在概念上有一定的区别。存活率要经过对数转换（或者直接采用对数标尺）后才能得到存活曲线类型,从动物的存活率曲线上直接判读存活曲线类型可能会导致错误的结论。鉴于存活曲线分析研究中出现的问题,建议在进行物种存活曲线类型的分析时,务必先进行对数转换。     

Testing environmental Kuznets curve hypothesis: The role of renewable and non-renewable energy consumption and trade in OECD countries

This paper investigates the causal relationships between per capita CO₂ emissions, gross domestic product (GDP), renewable and non-renewable energy consumption, and international trade for a panel of 25 OECD countries over the period 1980–2010. Short-run Granger causality tests show the existence of bidirectional causality between: renewable energy consumption and imports, renewable and non-renewable energy consumption, non-renewable energy and trade (exports or imports); and unidirectional causality running from: exports to renewable energy, trade to CO₂ emissions, output to renewable energy. There are also long-run bidirectional causalities between all our considered variables. Our long-run fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) estimates show that the inverted U-shaped environmental Kuznets curve (EKC) hypothesis is verified for this sample of OECD countries. They also show that increasing non-renewable energy increases CO₂ emissions. Interestingly, increasing trade or renewable energy reduces CO₂ emissions. According to these results, more trade and more use of renewable energy are efficient strategies to combat global warming in these countries.     

Finite-time Lyapunov exponents and metabolic control coefficients for threshold detection of stimulus–response curves

In biochemical networks transient dynamics plays a fundamental role, since the activation of signalling pathways is determined by thresholds encountered during the transition from an initial state (e.g. an initial concentration of a certain protein) to a steady-state. These thresholds can be defined in terms of the inflection points of the stimulus–response curves associated to the activation processes in the biochemical network. In the present work, we present a rigorous discussion as to the suitability of finite-time Lyapunov exponents and metabolic control coefficients for the detection of inflection points of stimulus–response curves with sigmoidal shape.     

海南石梅湾青皮林最小取样面积与物种多样性研究

石梅湾海岸青皮(Vatica hainanensis)林是海南独特的雨林群落之一。本文选用8种“种-面积渐近线”对该群落的最小取样面积进行了拟合研究。结果表明,其中5条曲线的R^2大于0．97,拟合状况很好,但所得出的最小取样面积各不相同。进一步经过“重要值-面积曲线”的群落特征分析,确认群落的最小取样面积只有800m^2。石梅湾青皮林最小取样面积比海南其他类型雨林、滇南热带雨林、东南亚热带雨林以及非洲雨林都要小。通过对1000m^2样地的物种多样性分析,结果表明：在垂直结构上,石梅湾青皮林B层乔木的Gleason指数大于A层乔木,和海南山地雨林的情况不同。海岸青皮林为物种多样性不高的单优林,群落的物种多样性、均匀度远小于海南其他类型的山地雨林与混合青皮林;在海岸青皮林群落内,青皮的相对密度、相对优势度、重要值大大高于其他物种。此研究表明：海南热带雨林同样存在物种多样性不高、单优特征显著的顶极群落;海南海岸青皮林是迄今为止热带雨林取样面积最小的森林类型。     

Prediction of Protein-Protein Interactions Using Protein Signature Profiling

Protein domains are conserved and functionally independent structures that play an important role in interactions among related proteins. Domain-domain inter- actions have been recently used to predict protein-protein interactions (PPI). In general, the interaction probability of a pair of domains is scored using a trained scoring function. Satisfying a threshold, the protein pairs carrying those domains are regarded as "interacting". In this study, the signature contents of proteins were utilized to predict PPI pairs in Saccharomyces cerevisiae, Caenorhabditis ele- gans, and Homo sapiens. Similarity between protein signature patterns was scored and PPI predictions were drawn based on the binary similarity scoring function. Results show that the true positive rate of prediction by the proposed approach is approximately 32% higher than that using the maximum likelihood estimation method when compared with a test set, resulting in 22% increase in the area un- der the receiver operating characteristic (ROC) curve. When proteins containing one or two signatures were removed, the sensitivity of the predicted PPI pairs in- creased significantly. The predicted PPI pairs are on average 11 times more likely to interact than the random selection at a confidence level of 0.95, and on aver- age 4 times better than those predicted by either phylogenetic profiling or gene expression profiling.