FISH ASSEMBLAGE RESPONSES TO DIFFERENT SECONDARY CHANNEL DESIGNS IN THE LOWER MISSISSIPPI RIVER,U.S.A.:A TEMPLATE FOR RIVER RESTORATION

The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that includes recreational and commercial fisheries. Due to river training and diversion structures constructed during the past 80 years, the historic characteristics of the LMR have been drastically altered and have likely influenced fishes and fisheries in the system. One common restoration measure used throughout the LMR has been to "notch" wing-dike structures that close secondary(side) river channels. Dike notching allows year-round flows through secondary channels, which enhances habitat diversity and promotes biological productivity at the ecosystem scale. Although notching is presumed good for LMR fishes and other biota, few studies have examined its effects on fish assemblages. In this study, fish assemblages were sampled at seven LMR secondary channels spanning from river kilometer(rkm) 628(Louisiana-Mississippi, U.S.A.) upstream to rkm 1504(Missouri-Kentucky, U.S.A.). Four secondary channels were termed "permanent"(i.e.,with notched dikes) while three secondary channels were termed "temporary"(i.e., without notched dikes).Fishes were sampled by boat-mounted electrofishing conducted during falling and low stages from1995—1997. Fish assemblages differed between permanent and temporary secondary channels, and varied somewhat between falling and low stages. Gizzard shad(Dorosoma cepedianum), threadfin shad(D. petenense), and white bass(Morone chrysops) demonstrated consistent preferences for low-current conditions associated with temporary secondary channels. Conversely, blue catfish(Ictalurus furcatus), flathead catfish(Pylodictis olivaris), and freshwater drum(Aplodinotus grunniens) were more associated with permanent secondary channels. Future restoration strategies in the LMR should consider dike notching and resultant maintenance of permanent secondary channels in selected river reaches. However, temporary secondary channels also contain unique fish species, and also appear to be important sites of riverine primary production. Restoration strategies should consider a balance of both secondary channel types, which should support the greatest biodiversity for the LMR ecosystem.     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.     

Effects of environmental stressors on stem cells

Environmental toxicants are ubiquitous,and many are known to cause harmful health effects.However,much of what we know or think we know concerning the targets and long-term effects of exposure to environmental stressors is sadly lacking.Toxicant exposure may have health effects that are currently mischaracterized or at least mechanistically incompletely understood.While much of the recent excitement about stem cells(SCs)focuses on their potential as therapeutic agents,they also offer a valuable resource to give us insight into the mechanisms and risks of toxicant effects.Not only as a response to the increasing ethical pressure to reduce animal testing,SC studies allow us valuable insight into the true effects of human exposure to environmental stressors under controlled conditions.We present a review of the history of publications on the effects of environmental stressors on SCs,followed by a consolidation of the literature over the past five years on a subset of key environmental stressors of importance to human health and their effects on both embryonic and tissue SCs.The review will make constructive suggestions as to areas of toxicant research where further studies are needed,as well as making indications of the potential utility for advancing knowledge and directing research on environmental toxicology.     

走进内蒙

2015年8月1日,我们每一个人收拾好行囊,整装待发,在邓涛老师带领下踏上了去往内蒙古的征程,拉开了探索灰色生命之旅的序幕. 队伍由两辆车、8人组成,我们早晨7点从中国科学院古脊椎动物与古人类研究所出发,披着清晨的阳光,摆脱城市的拥挤,缓缓地“逃离”了北京城.直到抵达张北之后我们的车子才能像矫健的马儿一样驰骋在广袤的公路上,沿途没有了城市的喧闹,没有了交通的堵塞,伴随我们的只有那一眼望去蓝蓝的天空、随风摆动的小草,以及那迷人的风景,偶尔打开车窗,一股凉爽的清风扑面而来,沁人心脾.经过一路的颠簸,我们在傍晚时刻到达锡林浩特,当地文物保护站的同志为我们安顿好了一切.     

例谈2007年高考"现代生物科技专题"

通过现代生物科技专题及相关高考试题的介绍与分析,以开拓学生视野,增强科技意识,激发学生探索生命奥妙和热爱生物科学的情感,为进一步学习现代生物学奠定基础.同时,借助现代生物科技专题作试题背景,具有能力的开放性和情境的新颖性,也有利于考查和培养学生独立获取新知识、收集和处理信息的能力.所选试题涉及现代生物科技前沿的领域有:基因工程、细胞工程、蛋白质工程、癌症和克隆技术等,均体现出对现代生物技术发展的关注.     

Formidable females redux:male social integration into female networks and the value of dynamic multilayer networks

The development of multilayer network techniques is a boon for researchers who wish to understand how different interaction layers might influence each other,and how these in turn might influence group dynamics.Here,we investigate how integration between male and female grooming and aggression interaction networks influences male power trajectories in vervet monkeys Chlorocebus pygerythrus.Our previous analyses of this phenomenon used a monolayer approach,and our aim here is to extend these analyses using a dynamic multilayer approach.To do so,we constructed a temporal series of male and female interaction layers.We then used a multivariate multilevel autoregression model to compare cross-lagged associations between a male's centrality in the female grooming layer and changes in male Elo ratings.Our results confirmed our original findings:changes in male centrality within the female grooming network were weakly but positively tied to changes in their Elo ratings.However,the multilayer network approach offered additional insights into this social process,identifying how changes in a male's centrality cascade through the other network layers.This dynamic view indicates that the changes in Elo ratings are likely to be short-lived,but that male centrality within the female network had a much stronger impact throughout the multilayer network as a whole,especially on reducing intermale aggression(i.e.,aggression directed by males toward other males).We suggest that multilayer social network approaches can take advantage of increased amounts of social data that are more commonly collected these days,using a variety of methods.Such data are inherently multilevel and multilayered,and thus offer the ability to quantify more precisely the dynamics of animal social behaviors.     

Plant infection by two different viruses induce contrasting changes of vectors fitness and behavior

Insect-vectored plant viruses can induce changes in plant phenotypes,thus influencing plant-vector interactions in a way that may promote their dispersal according to their mode of transmission (i.e.,circulative vs.noncirculative).This indirect vector manipulation requires host-virus-vector coevolution and would thus be effective solely in very specific plant-virus-vector species associations.Some studies suggest this manipulation may depend on multiple factors relative to various intrinsic characteristics of vectors such as transmission efficiency.In anintegrative study,we tested the effects of infection of the Brassicaceae Camelina sativa with the noncirculative Cauliflower mosaic virus (CaMV)or the circulative Turnip yellows virus (TuYV)on the host-plant colonization of two aphid species differing in their virus transmission efficiency:the polyphagous Myzus persicae,efficient vector of both viruses,and the Brassicaceae specialist Brevicoryne brassicae,poor vector of TuYV and efficient vector of CaMV.Results confirmed the important role of virus mode of transmission as plant-mediated effects of CaMV on the two aphid species induced negative alterations of feeding behavior (i.e.,decreased phloem sap ingestion)and performance that were both conducive for virus fitness by promoting dispersion after a rapid acquisition.In addition,virus transmission efficiency may also play a role in vector manipulation by viruses as only the responses of the efficient vector to plant-mediated effects of TuYV,that is,enhanced feeding behavior and performances,were favorable to their acquisition and further dispersal.Altogether,this work demonstrated that vector transmission efficiency also has to be considered when studying the mechanisms underlying vector manipulation by viruses.Our results also re- inforce the idea that vector manipulation requires coevolution between plant,virus and vector.     

Stem cell therapy applied for digestive anastomosis: Current state and future perspectives

BACKGROUND Digestive tract resections are usually followed by an anastomosis.Anastomotic leakage,normally due to failed healing,is the most feared complication in digestive surgery because it is associated with high morbidity and mortality.Despite technical and technological advances and focused research,its rates have remained almost unchanged the last decades.In the last two decades,stem cells(SCs)have been shown to enhance healing in animal and human studies;hence,SCs have emerged since 2008 as an alternative to improve anastomoses outcomes.AIM To summarise the published knowledge of SC utilisation as a preventative tool for hollow digestive viscera anastomotic or suture leaks.METHODS PubMed,Science Direct,Scopus and Cochrane searches were performed using the key words“anastomosis”,“colorectal/colonic anastomoses”,“anastomotic leak”,“stem cells”,“progenitor cells”,“cellular therapy”and“cell therapy”in order to identify relevant articles published in English and Spanish during the years of 2000 to 2021.Studies employing SCs,performing digestive anastomoses in hollow viscera or digestive perforation sutures and monitoring healing were finally included.Reference lists from the selected articles were reviewed to identify additional pertinent articles.METHODS Given the great variability in the study designs,anastomotic models,interventions(SCs,doses and vehicles)and outcome measures,performing a reliable meta-analysis was considered impossible,so we present the studies,their results and limitations.RESULTS Eighteen preclinical studies and three review papers were identified;no clinical studies have been published and there are no registered clinical trials.Experimental studies,mainly in rat and porcine models and occasionally in very adverse conditions such as ischaemia or colitis,have been demonstrated SCs as safe and have shown some encouraging morphological,functional and even clinical results.Mesenchymal SCs are mostly employed,and delivery routes are mainly local injections and cell sheets followed by biosutures(sutures coated by SCs)or purely topical.As potential weaknesses,animal models need to be improved to make them more comparable and equivalent to clinical practice,and the SC isolation processes need to be standardised.There is notable heterogeneity in the studies,making them difficult to compare.Further investigations are needed to establish the indications,the administration system,potential adjuvants,the final efficacy and to confirm safety and exclude definitively oncological concerns.CONCLUSION The future role of SC therapy to induce healing processes in digestive anastomoses/sutures still needs to be determined and seems to be currently far from clinical use.     

Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats

BACKGROUND Despite overt insulin resistance,adipocytes of genetically obese Zucker rats accumulate the excess of calorie intake in the form of lipids.AIM To investigate whether factors can replace or reinforce insulin lipogenic action by exploring glucose uptake activation by hydrogen peroxide,since it is produced by monoamine oxidase(MAO)and semicarbazide-sensitive amine oxidase(SSAO)in adipocytes.METHODS 3H-2-deoxyglucose uptake(2-DG)was determined in adipocytes from obese and lean rats in response to insulin or MAO and SSAO substrates such as tyramine and benzylamine.14C-tyramine oxidation and binding of imidazolinic radioligands[3H-Idazoxan,3H-(2-benzofuranyl)-2-imidazoline]were studied in adipocytes,the liver,and muscle.The influence of in vivo administration of tyramine+vanadium on glucose handling was assessed in lean and obese rats.RESULTS 2-DG uptake and lipogenesis stimulation by insulin were dampened in adipocytes from obese rats,when compared to their lean littermates.Tyramine and benzylamine activation of hexose uptake was vanadate-dependent and was also limited,while MAO was increased and SSAO decreased.These changes were adipocyte-specific and accompanied by a greater number of imidazoline I2 binding sites in the obese rat,when compared to the lean.In vitro,tyramine precluded the binding to I2 sites,while in vivo,its administration together with vanadium lowered fasting plasma levels of glucose and triacylglycerols in obese CONCLUSION The adipocytes from obese Zucker rats exhibit increased MAO activity and imidazoline binding site number.However,probably as a consequence of SSAO down-regulation,the glucose transport stimulation by tyramine is decreased as much as that of insulin in these insulin-resistant adipocytes.The adipocyte amine oxidases deserve more studies with respect to their putative contribution to the management of glucose and lipid handling.     

向日葵生殖生长不同时期向光运动日变化的观察

通过观测可以确定向日葵的确具有明显跟随太阳旋转的向光性,但处于不同时期的向日葵有很大差异:处于花蕾早期的向日葵从日出到日落跟随太阳由东经南再向西运动且有明显的滞后现象.盛花期的向日葵花盘基本固定朝向东方,不跟随太阳运动,但仍有小范围偏转.     

中国地衣新记录属——黑渍衣属

<正>INTRODUCTION During our study of crustose lichens collected from Mt.Taibai,Shaanxi Province,we discovered an unusual species Orphniospora moriopsis (A.Massal.) D.Hawksw.It is characterized by the dark brown areolate thallus, black apothecia and brown spores.Orphniospora belongs to Fuscideaceae,Teloschistales,Lecanoromycetidae, Ascomycetes,Ascomycota (Kirk et al.,2001).The genus is reported from China for the first time.     

Therapeutic effects of menstrual blood-derived endometrial stem cells on mouse models of streptozotocin-induced type 1 diabetes

BACKGROUND Type 1 diabetes(T1D),a chronic metabolic and autoimmune disease,seriously endangers human health.In recent years,mesenchymal stem cell(MSC)transplantation has become an effective treatment for diabetes.Menstrual bloodderived endometrial stem cells(MenSC),a novel MSC type derived from the decidual endometrium during menstruation,are expected to become promising seeding cells for diabetes treatment because of their noninvasive collection procedure,high proliferation rate and high immunomodulation capacity.AIM To comprehensively compare the effects of MenSC and umbilical cord-derived MSC(UcMSC)transplantation on T1D treatment,to further explore the potential mechanism of MSC-based therapies in T1D,and to provide support for the clinical application of MSC in diabetes treatment.METHODS A conventional streptozotocin-induced T1D mouse model was established,and the effects of MenSC and UcMSC transplantation on their blood glucose and serum insulin levels were detected.The morphological and functional changes in the pancreas,liver,kidney,and spleen were analyzed by routine histological and immunohistochemical examinations.Changes in the serum cytokine levels in the model mice were assessed by protein arrays.The expression of target proteins related to pancreatic regeneration and apoptosis was examined by western blot.RESULTS MenSC and UcMSC transplantation significantly improved the blood glucose and serum insulin levels in T1D model mice.Immunofluorescence analysis revealed that the numbers of insulin+and CD31+cells in the pancreas were significantly increased in MSC-treated mice compared with control mice.Subsequent western blot analysis also showed that vascular endothelial growth factor(VEGF),Bcl2,Bcl-xL and Proliferating cell nuclear antigen in pancreatic tissue was significantly upregulated in MSC-treated mice compared with control mice.Additionally,protein arrays indicated that MenSC and UcMSC transplantation significantly downregulated the serum levels of interferonγand tumor necrosis factorαand upregulated the serum levels of interleukin-6 and VEGF in the model mice.Additionally,histological and immunohistochemical analyses revealed that MSC transplantation systematically improved the morphologies and functions of the liver,kidney,and spleen in T1D model mice.CONCLUSION MenSC transplantation significantly improves the symptoms in T1D model mice and exerts protective effects on their main organs.Moreover,MSC-mediated angiogenesis,antiapoptotic effects and immunomodulation likely contribute to the above improvements.Thus,MenSC are expected to become promising seeding cells for clinical diabetes treatment due to their advantages mentioned above.     

Fighting and aggressive sound determines larger male to win male-male competition in a bark beetle

Intrasexual selection occurs in male-male competition over access to females and usually results in the larger male winning.While much research has documented that size matters,little is known about how the larger male wins.Dendroctonus vale ns is an aggregating monogamous bark beetle in which males have large variation in body size and display intense competition over females.Behavioral observation showed two males fight each other within the gallery by pushing/shoving and stridulated more when two males encountered each other.Experiments using two different-sized males synchronously competing showed that larger males won 95%of contests.Reciprocal displacement experiments using muted and intact males of different or equal size were used to simulate male-male competition.Larger males displaced the smaller resident male in 90%of contests,while smaller males prevailed over larger residents in 6.7%of contests.With both males silenced,larger males displaced smaller males in 80%of con tests,while smaller males prevailed in 8%of con tests.Further experiments using equal-sized males showed aggressive soundemitting males displaced muted males in 67%of contests,yet intact males displaced other intact males in only 37.5%of con tests.Sound analysis showed sound pressure level is an honest signal of body size and males chose soft sounds over loud aggressive sounds in assays.Therefore,D.valens males have evolved dual behaviors,fighting and aggressive sounds associated with body size,to assess rivals to compete for a partner,gaining insights in male-male competition for this species and for other animals.     

The Human Ankle-Foot Complex as a Multi-Configurable Mechanism during the Stance Phase of Walking

<正> The objective of this study is to investigate the biomechanical functions of the human ankle-toot complex during the stancephase of walking. The three-dimensional (3D) gait measurement was conducted by using a 3D infrared multi-camera system anda force plate array to record the Ground Reaction Forces (GRF) and segmental motions simultaneously. The ankle-foot complexwas modelled as a four-segment system, connected by three joints: talocrural joint, sub-talar joint and metatarsophalangeal joint.The subject-specific joint orientations and locations were determined using a functional joint method based on the particleswarm optimisation algorithm. The GRF moment arms and joint moments acting around the talocrural and sub-talar joints werecalculated over the entire stance phase. The estimated talocrural and sub-talar joint locations show noticeable obliquity. Thekinematic and kinetic results strongly suggest that the human ankle-foot complex works as a mechanical mechanism with twodifferent configurations in stance phase of walking. These lead to a significant decrease in the GRF moment arms therebyincreasing the effective mechanical advantages of the ankle plantarflexor muscles. This reconfigurable mechanism enhancesmuscle effectiveness during locomotion by modulating the gear ratio of the ankle plantarflexor muscles in stance. This studyalso reveals many factors may contribute to the locomotor function of the human ankle-foot complex, which include not only itsre-configurable structure, but also its obliquely arranged joints, the characteristic heel-to-toe Centre of Pressure (COP) motionand also the medially acting GRF pattern. Although the human ankle-foot structure is immensely complex, it seems that itsconfiguration and each constitutive component are well tuned to maximise locomotor efficiency and also to minimise risk ofinjury. This result would advance our understanding of the locomotor function of the ankle-foot complex, and also the intrinsicdesign of the ankle-foot musculoskeletal structure. Moreover, this may also provide implications for the design of bionicprosthetic devices and the development of humanoid robots.     

英格兰喀斯特瀑布苔藓植物水生群落生态研究

喀斯特(Karst)是指在可溶性碳酸盐岩(主要石灰岩和白云岩)上发育并演化而形成的独特地貌类型[1,2].     

MNP-SH复合物一步法快速分离和纯化mRNA的新方法

本文建立了一种快速分离和纯化mRNA的新方法.为避免RT-PCR实验中mRNA降解问题,我们使用磁性纳米粒子,快速儋有效的从培养的细胞、组织以及脐带血中分离出带有ploy(A) 结尾的mRNA用于实验.研究结果表明,磁性纳米粒子经过修饰连接Oligo(dT)16可直接分离mRNA,其方法操作简单,快捷、省时,可有效地用于基因表达的研究.     

均匀设计法优化高丽参多糖的提取

利用均匀设计法优化了高丽参多糖的提取过程.主要考察料液质量比、浸泡时间、提取温度和提取时间四个因素对提取率的影响.通过数学模型得到最优提取状况和3D曲面图.结果表明,提取温度对高丽参多糖得率影响最大,在料液质量比1:35、浸泡时间135 min、水提取温度81℃条件下提取156 min,高丽参多糖最大理论提取率为49.51%.最优化模型下实际多糖得率49.29%与理论得率相符.     

猪圆环病毒2型（PCV2）核衣壳蛋白免疫原性的鉴定和应用及其多抗在PCV2感染诊断中的应用

猪圆环病毒2型ORF2编码与病毒毒力相关的结构蛋白--核衣壳蛋白(Cap),该蛋白可以用于PCV2感染的血清学调查,但不同区域的PCV2分离株的ORF2特别是其抗原表位序列存在一定的突变.本研究将PCV2浙江分离株ORF2的主要抗原表位以及PCV1 ORF2进行了原核表达,将分别纯化的融合蛋白Cap2s和Cap1s免疫SPF兔后制备多抗,并进一步分析了纯化蛋白的免疫原性和多抗的特性.Western blot结果表明无论Cap2s和Cap1s均能与两个多抗发生交叉反应,而PCV2或PCV1阳性猪血清只能分别特异性地识别Cap2s和Cap1s.IFA结果则证明两个多抗对于天然Cap蛋白无交叉反应性.利用Cap2s作为包被抗原对13个猪场的259份血清样品的PCV2抗体进行ELISA检测,平均阳性率为80.69%(209/259),而各猪场的阳性率差异较大(48.28%～100%).以上结果表明Cap2s可作为一个型特异性抗原用于浙江省本地猪场猪群血清中PCV2抗体的监控,而其多抗也可用于免疫组化对PCV2感染进行有效诊断.     

RNAi-分子免疫系统

RNA干扰(RNA interference,RNAi)或RNA沉默是广泛存在于从植物到哺乳动物的真核生物体中小RNA诱导的基因沉默机制.该领域新的研究进展清楚表明在植物和动物中KNAi起着天然抗病毒作用.因此,KNAi常被视为有效的分子免疫系统.深入理解该分子免疫系统非常有助于揭示一些病毒病的致病机制和开发有效的抗病毒疗法.因此,就该分子免疫系统的研究进展作以综述.     

A Sound Quality Objective Evaluation Method Based on Auditory Peripheral Simulation Model

##正## Based on auditory peripheral simulation model, a new Sound Quality Objective Evaluation (SQOE) method is presented,which can be used to model and analyze the impacts of head, shoulder and other parts of human body on sound wave trans-mission.This method employs the artificial head technique, in which the head related transfer function was taken into account tothe outer ear simulation phase.First, a bionic artificial head was designed as the outer ear model with considering the outersound field in view of theory and physical explanations.Then the auditory peripheral simulation model was built, which mimicsthe physiological functions of the human hearing, simulating the acoustic signal transfer process and conversion mechanismsfrom the free field to the peripheral auditory system.Finally, performance comparison was made between the proposed SQOEmethod and ArtemiS software, and the verifications of subjective and objective related analysis were made.Results show thatthe proposed method was economical, simple, and with good evaluation quality.