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.     

Applications of stem cells and bioprinting for potential treatment of diabetes

Currently, there does not exist a strategy that can reduce diabetes and scientists are working towards a cure and innovative approaches by employing stem cellbased therapies. On the other hand, bioprinting technology is a novel therapeutic approach that aims to replace the diseased or lost β-cells, insulin-secreting cells in the pancreas, which can potentially regenerate damaged organs such as the pancreas. Stem cells have the ability to differentiate into various cell lines including insulinproducing cells. However, there are still barriers that hamper the successful differentiation of stem cells into β-cells. In this review, we focus on the potential applications of stem cell research and bioprinting that may be targeted towards replacing the β-cells in the pancreas and may offer approaches towards treatment of diabetes. This review emphasizes on the applicability of employing both stem cells and other cells in 3 D bioprinting to generate substitutes for diseased β-cells and recover lost pancreatic functions. The article then proceeds to discuss the overall research done in the field of stem cell-based bioprinting and provides future directions for improving the same for potential applications in diabetic research.     

Behavioral and neural auditory thresholds in a frog

Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they can hear. Thus a fundamental question linking neurobiology and sexual selection asks-what is the threshold for detecting acoustic sexual displays? In this study, we use 3 methods to assess such thresholds in tdngara frogs: behavioral responses, auditory brainstem responsesz and multi unit electrophysiological recordi ngs from the midbrain.We show that thresholds are lowest for multiunit recordings (ca. 45 dB SPL), and then for behavioral responses (ca. 61 dB SPL), with auditory brainstem responses exhibiting the highest thresholds (ca. 71 dB SPL). We discuss why these estimates differ and why, as with other studies, it is unlikely that they should be the same. Although all of these studies estimate thresholds they are not measuring the same thresholds;behavioral thresholds are based on signal salienee whereas the 2 neural assays estimate physiological thresholds. All 3 estimates, however, make it clear that to have an appreciation for detection and salienee of acoustic signals we must listen to those signals through the ears of the receivers.     

中国省级行政区生态环境可持续性评价

从自然条件、人类胁迫、生态环境效应和社会响应4个主题出发,构建了包含28个指标的中国省级行政区生态环境可持续性评价指标体系,并通过专家调查和层次分析法为各主题层中的指标赋权.分别用各主题层中的指标和对应的权重,采用加权平均法构建自然条件(NSI)、人类胁迫(HPI)、生态环境效应(EEI)和社会响应(SRI)4个分指数,然后用这4个分指数通过灰色关联法构建综合生态环境可持续性指数(CEI),对我国各省级行政区生态环境可持续性进行评价.同时论文通过主成分分析法和相关分析法分析造成各指数地域差异的主导因素和评价中指标赋权的合理性.最后以4个分指数作为变量,采用快速样本聚类法对我国31个省级行政区进行聚类分析.评价结果表明,2003年我国各生态环境指数存在显著的地域差异.自然条件从东南到西北呈明显的由优到劣的过渡趋势,降雨量、年均气温、森林覆盖率和水网密度4个指标是导致地域差异的主导因素;人类胁迫东部发达地区明显高于西部和中部地区,同一个地区经济发展水平存在显著的正相关;生态环境效应西北地区最为显著,同各地区自然条件存在显著的负相关,在人类活动干扰下,自然条件差的地区更容易发生生态损害与退化;社会响应无明显的地域分析规律,各地区经济发展水平对其有一定影响,但并非决定性因素.区域综合生态环境可持续性由区域NSI、HPI、EEI和SRI共同决定,综合评价得到2003年我国各省级行政区生态环境可持续性排序情况,其中生态环境可持续性最强的几个地区为海南、云南、广西、江西等地,最弱的几个地区为内蒙古、宁夏、上海、西藏、新疆等地.最后,聚类分析把我国31个省级行政区聚为生态环境特点各异的六大类,可以促进我国生态环境的分类管理.     

A lubricant boundary condition for a biological body lined by a thin heterogeneous biofilm

We study the asymptotic behavior of an incompressible viscous fluid flow in a biological body lined by a thin biological film with a cellular microstructure,varying thickness,and a heterogeneous viscosity regulated by a time random process.Let ting the thickness of the film tend to zero,we derive an effective biological slip boundary condition on the boundary of the body.This law relates the tangential fluxes to the tangential velocities via a proportional coefficient corresponding to the energy of some local problem.This law describes the ability of the biological film to function as a lubricant reducing friction at the wall of the body.The tangential velocities are functions of the random trajectories of a finely concentrated biological particle.     

猛犸雪原

正我对东北的了解和向往,最早来自上世纪70年代初期读过的描写北大荒知青生活的小说《征途》。我最感兴趣的是书中描述的东北的自然风光和动物植物:"遮天蔽日的红松林,尽管被大雪覆盖,但远远望去,依然是郁郁苍苍。朔风吹过,发出万马奔腾的松涛声。那一望无际的桦树林,好像千百株银枝玉树,俊秀挺拔地屹立在冰天雪地中";"咱这疙瘩呀,是‘棒打獐子瓢舀鱼,雉鸡飞到饭锅里’。汽车在公路上撞死几个挡道的狍子,跟你们南方碾死一条蛇一样不稀     

我国近代发酵工业的先驱——金培松

金培松(又名金柏卿,英文名Pei-sung King)1906年10月30日生于浙江省东阳后岑山村.童年时他是在农村渡过,牛角挂书,放牛识字.1919年进入东阳县长山小学,1923年高小毕业,入东阳县城初级中学,3年后毕业,考入浙江省立第一中学高中部,1年后因家庭经济困难辍学,1927年9月以高中肄业学历被上海劳动大学农学院农艺化学系录取,1931年毕业.     

Species Account of Anura ns from the Western Slope of Mt. Kita nglad,Mindanao Island,Philippines

The Mt. Kitanglad Range is one of the country’s important key biodiversity sites;however, information about anuran diversity in this protected area remains depauperate. Herein we provided accounts of anuran species from high-elevation forests, in three sites of the western slope of Mt. Kitanglad range. The combined belt-transect sampling and microha bitat searches accounted for 13 species representing five families. The most represented family was Rhacophoridae with five representative species of the genus Philautus. Twelve out of the 13 species documented in the current survey are endemic. Four previously unaccounted species(Pelophr yne brevipes, Pulchrana grandocula, Sanguirana mearnsi, and Philautus surrufus) were added and brought the total anurans known from Mt. Kitanglad to 26 species. Most of the species were also recorded in forested sites, suggestive of their lesser affinity to non-forested ecosystems. The additional species detected during our survey may also imply that full understanding of anuran diversity of Mt. Kitanglad remains far from complete.     

2008年春鄱阳湖区斑背大尾莺状况

2008年1月下旬至2月上旬在中国南方广大地区发生冻雨雪灾害,给在鄱阳湖区越冬的斑背大尾莺(Locustella pryeri)带来不利影响,据3月上旬的调查,原本在江西鄱阳湖南矶湿地国家级自然保护区内广泛分布的斑背大尾莺已变得十分稀少.     

汉滩病毒S片段基因编码区在Vero—E6细胞中的表达

汉滩病毒属于布尼亚病毒科汉坦病毒属,主要引起人类肾综合征出血热［１］。我国是肾综合征出血热发生和流行的主要疫区,该病起病急、病死率高,流行范围广,因此寻找安全有效、低廉的疫苗是控制本病流行和发生的关键。基因免疫是近年来微生物学和免疫学研究的新热点［２...     

汉滩病毒S片段基因编码区在Vero-E6细胞中的表达

The coding region of S genome segment of Hantaan virus (76/118 strain) was inserted into the eukarytic expression plasmidpVR1012. The recombinant expression plasmid pVRS₂₂ was constructed. Vero-E₆ cells were transiently transfected in vitro with pVRS₂₂ plasmid. The transient expression of Hantaan virus nucleocapsid proteins in Vero-E₆ cells was detected by indirect immunofluorescence assay (IFA) with monoclonal antibody 5H5 against Hantaan virus.     

插入CpG序列的汉坦病毒S基因真核表达载体的构建及表达

To improve the effect of the gene immunization against Hantaan virus, we constructed the eukaryotic expression vector pTARGET-hans(ISS) containing Hantaan Virus S gene coding region and CpG motif by cloning S gene segment with CpG motif into eukaryotic expression vector pTARGET^TM.After conformed by enzyme analysis, the recombinant expression vector pTARGET-hans(ISS) was transferred into Vero-E6 cells by electroporation and the transient expression of Hantaan virus nucleocapsid protein was detected by indirect immunofluorescence assay(IFA). In some transferred Vero-E6, the green fluorescence was showed, thus we can conclude that the eukaryotic expression vector pTARGET-hans(ISS) was successfully constructed and expressed in vitro,which will lay a foundation for further animal vaccination.     

引入CpG基序的汉滩病毒G2糖蛋白基因的克隆及表达

构建汉滩病毒G2糖蛋白的真核表达载体,并加入可增强小鼠免疫刺激作用的CpG基序,检测其可否在真核细胞中表达。参照Genebank中汉滩病毒M的全基因序列设计引物,引物两端引入可增强小鼠免疫刺激作用的CpG基序及双酶切位点,通过聚合酶链反应(PCR)获得含CpG基序的G2片段,并将其与T载体pMD18-T相连,测序后克隆至真核表达载体pcDNA3.1 上,将此真核表达载体以脂质体法转染至真核细胞Vero-E6中,利用间接免疫荧光法(IFA)检测发现转染后的Vero-E6中出现特异性的绿色荧光。结果表明本实验成功构建了汉滩病毒包膜糖蛋白G2的重组体。     

汉坦病毒囊膜糖蛋白G1基因重组腺病毒载体的构建及其在Vero E6细胞中的表达

拟构建汉坦病毒Gl基因重组腺病毒载体并在VeroE6细胞中表达,为汉坦病毒基因疫苗的研究提供实验基础。PCR法从含汉坦病毒-76118株M基因的M56质粒扩增糖蛋白G1基因片段,利用穿梭质粒pShuttle,将其克隆入Adeno—X病毒DNA,获得重组腺病毒DNA,转染HEK293细胞,包装、扩增后得到汉坦病毒Gl基因重组腺病毒原种,感染VetoE6细胞,用IFA法和ELISA法检测表达产物。得到了含汉坦病毒G1基因的重组腺病毒,其滴度约为10^11pfu／ml,感染VeroE6细胞后检测到汉坦病毒糖蛋白G1的表达。     

汉滩病毒感染诱导热休克蛋白70表达

为了解汉滩病毒感染后细胞的应激反应及ＨＳＰ７０的表达与病毒复制的关系,在汉滩病毒Ａ９株感染Ｖｅｒｏ－Ｅ６细胞后,用免疫组织化学及核酸分子原位杂交法,对细胞ＨＳＰ７０基因的表达进行了检测。结果表明,汉滩病毒感染细胞４ｈｙ后即可诱导Ｖｅｒｐ－Ｅ６细胞表达ＨＳＰ７０,表达可持续至感染后５ｄ且ＨＳＰ７０在细胞内的分布也有改变。提示汉滩病毒可直接诱导ＨＳＰ７０的高表达。     

在大肠杆菌中分别表达汉滩病毒素膜糖蛋白G1和G2

利用PCR方法扩增了汉滩病毒76－118株囊膜糖蛋白G1和G2的编码区基因,并将PCR产物克隆到T-载体中,用限制性内切酶将G1和G2的编码区基因切下,并克隆到表达载体pBV220中构建G1和G2的表达质粒。诱导表达后在SDS－PAGE凝胶中未见表达产物带,表达的G1和G2能与部分抗G1和G2的单克隆抗体发生反应,但用Western－blot方法不能检测到表达产物。用表达的G1和G2免疫小白鼠能刺激小白鼠产生特异性抗汉摊病毒的抗体,间接免疫荧光抗体的滴度可分别达到1:160和1：320。     

Identification of chikungunya virus interacting proteins in mammalian cells

Identification and characterization of virus host interactions is an essential step for the development of novel antiviral strategies. Very few studies have been targeted towards identification of chikungunya virus (CHIKV) interacting host proteins. In current study, virus overlay protein binding assay (VOPBA) and matrix-assisted laser desorption/ionization time of flight analysis (MALDI TOF/TOF) were employed for the identification of CHIKV binding proteins in mammalian cells. HSP70 and actin were identified as virus binding proteins in HEK-293T and Vero-E6 cells, whereas STAT-2 was identified as an additional protein in Vero-E6 cells. Pre-incubation with anti-HSP70 antibody and miRNA silencing of HSP70 significantly reduced the CHIKV production in HEK-293T and Vero-E6 cells at early time points. These results suggest that CHIKV exploits the housekeeping molecules such as actin, HSP70 and STAT-2 to establish infection in the mammalian cells.     

流行性出血热病毒在Vero一E6细胞内引起细胞病变作用的新发现

自McCormick等发现Vero-E6细胞对流行性出血热病毒的敏感性后,国内外已有不少学者应用该细胞进行病毒分离和试验研究,但均未发现病毒在该细胞内规律性病变。病毒的存在和滴度只能按免疫荧光法(IFA)证实和测出。本文应用我国分离的出血热病毒在Vero-E6细胞上培养和观察,发现病毒在该细胞上出现有规律的病变并能测出病毒滴度,病变能被特异性中和抗体中和。现将结果报道如下。