Diet and feeding behavior of a group of high-altitude rhesus macaques: high adaptation to food shortages and seasonal fluctuations

Diet and feeding behavior data are crucial to a deep understanding of the behavioral response and adaptation of primates to a high-altitude environment.From August 2019 to June 2021,we collected data on the feeding behavior of a high-altitude rhesus macaque Macaca mulatta group from Yajiang County,Western Sichuan Plateau,which has an altitude of over 3,500 m.The results showed that feeding(33.0±1.8%)and moving(28.3±2.6%)were the dominant behavior of rhesus macaques.Macaques ate 193 food items,comprising 11 food categories from 90 species.Our study found that plant roots(30.9±30.1%)and young leaves(28.0±33.1%)were the main foods eaten by macaques.The preferred foods of rhesus macaques were young leaves,fruits,and seeds,and the consumption of these items was positively correlated with its food availability.When the availability of preferred foods was low,macaques took plant roots,barks,and fallen leaves as fallback foods.In particular,roots were a dominant food item in winter,and this way of feeding became a key survival strategy.Our results suggest that,facing the relative scarcity and strong seasonal fluctuations of food resources in high-altitude habitat,macaques adopt active foraging strategies,relying on a variety of food species and adjusting flexibly their food choices based on food availability,which may help to maximize the energy efficiency of high-altitude macaques.

Discovery of thiosemicarbazone derivatives as effective New Delhi metallo-β-lactamase-1(NDM-1) inhibitors against NDM-1 producing clinical isolates

New Delhi metallo-b-lactamase-1(NDM-1)is capable of hydrolyzing nearly allβ-lactam antibiotics,posing an emerging threat to public health.There are currently less effective treatment options for treating NDM-1 positive"superbug",and no promising NDM-1 inhibitors were used in clinical practice.In this study,structure eactivity relationship based on thiosemicarbazone derivatives wassystematically characterized and their potential activities combined with meropenem(MEM)were evaluated.Compounds 19 bg and 19 bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance.Further studies demonstrated compounds 19 bg and 19 bh were uncompetitive NDM-1 inhibitors with Ki Z 0.63 and 0.44 mmol/L,respectively.Molecular docking speculated that compounds 19 bg and 19 bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem.Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/m L against red blood cells.In vivo experimental results showed combination of MEM and compound 19 bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice.Our finding showed that compound 19 bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.

基于被动控制装置的高速列车转向架区域气动优化

高速列车转向架是重要的气动阻力和噪声来源,这两者都会对高速列车气动性能和乘客的舒适性带来不利影响.在本研究中,将被动控制的方法应用于高速列车转向架舱的设计,以改善其气动性能.本研究引入了两种被动控制措施,即加装扰流片和在转向架舱附近设置导流槽.本文采用改进的延迟分离涡模拟(IDDES)和声学有限元法(FEM),对高速列车不同被动控制策略下的气动特性和气动声学特性进行了数值研究,分析并讨论了被动控制装置对减阻、周围气流和气动噪声特性的影响.研究结果表明,被动控制装置对列车周围气流有重要影响.列车前半部分脉动压力幅值高于后半部分.无论是否加装被动控制装置,第一个转向架处的声压振幅都是最大的.对于远场区域,在转向架舱前安装扰流片和放置导流槽可以明显降低气动阻力和噪声.因此,如本研究所示,采用被动控制方法来改善高速列车气动特性和噪声特性是一种可行的选择.