Comparison of Ground Water Bacterial Cell Sizes from the Agricultural, Domestic and Industrial Areas of Mysore District, Karnataka State, India

A two-year study on temporal variations in the ground water heterotrophic bacterial cell sizes of free living bacteria(FLB)and particle bound bacteria(PBB)from the agricultural,domestic and industrial areas was carried out from Februar y2005 to January 2007.The overall mean cell length of FLB and PBB was similar in all the ground water studied.However,the season wise grouped data revealed significant seasonal changes in cell length of FLB and PBB,as smaller bacteria were noticed during rainy season in the ground water in agricultural area in both the years,and only in the second year of study in domestic and industrial areas.Generally,it was noticed that there were summer maximum and rainy minimum values of the cell length of PBB in the ground water in agricultural,domestic and industrial areas in the second year of study.The Pearson's correlations showed the presence of 8(in agricultural area),5(in domestic)and 3(in industrial) significant correlations with environmental(Physico-chemical)parameters,respectively.The regression analysis revealed that as much as 12%of variation in the mean length of FL Bwas due to NO3( )in agricultural area and 9%due to total solids( )indomestic area.However,the 8% variation in bacterial cell size of FLB was due to Mg( )in industrial area.Whereas,13%variation in mean length of PBB was due to S04( )in agncultural area and 10%due to total anions of strong acid(TASA)( )in domestic area.Furthermore,10% of variation Was due to PO4( )in industrial area.Thus,the statistical analysis revealed that several environmental variables were potentially responsible for some of the temporal variations in aquatic heterotrophic bacterial cell size,suggesting probably the stressed environment in these ecosystems.     

Using the maximum principle of impulse control for ecology-economical models

In this work we present mathematical models for population of single cohort and homogeneous animals. Investigating these mathematical models, we determine structure of optimal impulsive control which used maximum principle for optimal processes with impulse control.     

Current Trends in Plant and Animal Population Monitoring

Abstract:  Animal and plant population monitoring programs are critical for identifying species at risk, evaluating the effects of management or harvest, and tracking invasive and pest species. Nevertheless, monitoring activities are highly decentralized, which makes it difficult for researchers or conservation planners to get a good general picture of what real-world monitoring programs actually entail. We used a Web-based survey to collect information on population monitoring programs. The survey focused on basic questions about each program, including motivations for monitoring, types of data being collected, spatiotemporal design of the program, and reasons for choosing that design. We received responses from 311 people involved in monitoring of various species and used these responses to summarize ongoing monitoring efforts. We also used responses to determine whether monitoring strategies have changed over time and whether they differed among monitoring agencies. Most commonly, monitoring entailed collection of count data at multiple sites with the primary goal of detecting trends. But we also found that goals and strategies for monitoring appeared to be diversifying, that area-occupied and presence–absence approaches appeared to be gaining in popularity, and that several other promising approaches (monitoring to reduce parameter uncertainty, risk-based monitoring, and directly linking monitoring data to management decisions) have yet to become widely established. We suggest that improved communication between researchers studying monitoring designs and those who are charged with putting these designs into practice could further improve monitoring programs and better match sampling designs to the objectives of monitoring programs.     

鄱阳湖水体细菌群落组成及遗传多样性

利用建立细菌16S rRNA基因文库和限制性内切酶长度多态性(RFLP)分析的方法,对鄱阳湖南、北湖区水体的细菌多样性进行了研究. 结果表明,鄱阳湖水体细菌多样性较高,且南湖区2007年水体的细菌多样性明显高于其2006年水体和北湖区水体. 主要细菌组成分析表明,鄱阳湖水体中的349个阳性克隆代表的167种基因型分别属于十大细菌类群,变形菌门(Proteobacteria)在4个克隆文库中占据了47%～81%,数量极其丰富,尤其是亚型的β-变形菌为优势菌群; 拟杆菌门(Bacteroidetes)和放线菌门(Actinobacteria)也广泛分布,且有2.9%～17.1%的克隆数属于未分类细菌. 研究结果进一步提示鄱阳湖水体有一定程度的富营养化.      

Mathematical modelling for conservation and management of gorgonians corals: youngs and olds,could they coexist?

Gorgonian corals are long-lived, slow-growing marine species dominating Mediterranean rocky bottoms. Endowed with complex morphologies they give a structure to the whole community, moreover, being efficient suspension feeders, they play a key role in plankton-benthos energy flow and CO₂${\text{CO}}_2$ storage. Thus, the structure and the development of benthic, hard bottom communities are linked to gorgonian survival. The red coral Corallium rubrum (L. 1758) is a precious gorgonian endemic to the Mediterranean Sea. Harvested and traded world-wide since ancient times red coral is a clear example of overexploited marine resource. This species is structured into self-seeding, genetically differentiated populations, some of which, living in the shallower part of the species bathymetric distribution, was recently affected by anomalous mortality events linked to global climate change. The co-occurrence of overharvesting and mass mortality could dramatically affect such populations. Demographic population models, widely applied by conservation biologists to check population viability and to project population trends over time are fundamental to foster survival of such populations matching harvesting to population growth rates. Therefore we set out a dynamic model of a genetically differentiated red coral population living in shallow waters. This population is characterised by small/young, crowded colonies and high recruitment rate. On the basis of the size–age structure determined for this population, a static life-history table, in which survival and reproduction coefficients of the different size–age classes were reported, has been set out. Demographic data were included in a non-linear, discrete, age-structured dynamic model, based on a Leslie-Lewis transition matrix. Our field data indicate that the recruits-to-larvae ratio is actually density-dependent. Such dependence, positive for low and negative for high density values, was included into the model and the effect of colonies of different size–age classes on recruits-to-larvae ratio was considered to be proportional to the number of polyps they have. We applied such model to simulate the trends of the studied population under different increases of survival and life-span. As some populations of gorgonians actually show the dominance of sparse, big/old colonies and low recruitment rate, while others are characterised by crowded, small/young colonies and high recruitment rate, we simulated the shift from the former to the latter structure increasing survival and life-span. Our results suggest that a dramatic mortality increase of bigger–older colonies (due, in the case of red coral to overfishing) could have determined the population structure we found.     

蚯蚓/铈锰改性生物炭对As污染红壤中细菌多样性和群落结构的影响

在明确铈锰改性生物炭(MBC)和赤子爱胜蚓(Eisenia foetida)联合修复可有效固定红壤As的前提下,采用高通量测序技术,探讨MBC与赤子爱胜蚓联合作用对As污染红壤中细菌多样性和群落结构的影响.结果表明,蚯蚓与生物炭/MBC单一和联合处理中,细菌多样性指数均以单一蚯蚓处理下最高,而单一生物炭、MBC的施用均...     

Cd对前沟藻(Amphidinium hoefleri)生产二甲基硫(DMS)影响的实验研究

为了探讨Ｃｄ污染对海藻ＤＭＳ生产的可能影响,以模拟实验方法,为期３周进行Ｃｄ对海洋甲藻类的前沟藻（Ａｍｐｈｉｄｉｎｉｕｍ ｈｏｅｆｌｅｒｉ）生产ＤＭＳ的实验室研究。结果表明,Ｃｄ可以抑制前沟藻种数数量的增长,对照组藻细胞最大数量是高浓度组（１０ｍｇ／Ｌ）的２５倍;Ｃｄ可以促进前沟藻细胞生产ＤＭＳ,其中高浓度组细胞ＤＭＳ产率大约是对照组的１０倍;Ｃｄ对藻数量的抑制作用和对藻生产ＤＭＳ的促进作用共同作     

人口规模预测的GM(1，1)模型应用初探

本文以山东省人口统计数据为依据,运用灰色系统理论探讨和分析了灰色建模基础数据的前滤波作用对模型精度的影响。结果表明,前滤波可极大提高模型预测值的精度     

基于人口分布与土地利用关系的人口数据空间化研究——以西藏自治区为例

土地是人与自然相互作用的产物,人口分布与土地利用具有非常密切的关系。根据1999年全国市县统计人口数据与各市县土地利用类型指数的相关性分析,发现各市县平均人口密度与各市县各类土地利用指数的复相关系数为0.82,在西藏、青海和海南3省区,复相关系数均达到0.99。以西藏自治区为例,根据市县人口密度与土地利用指数及数字高程的相关关系建立了人口数据空间化模型,并计算出西藏自治区1km×1km分辨率的栅格人口数据。在被选作验证区的3县37个乡镇中,用模型计算出的各乡镇人口密度与各乡镇的实际人口密度的相关系数为0.88。因此,土地利用信息是进行市县级人口统计数据空间化的重要参数,利用土地利用与人口分布之间客观存在的关系可以进行市县级人口统计数据的空间化。     

浅析水资源与人口、经济和社会环境的关系

水资源是人类社会生存和发展的物质基础,水资源问题是涉及到包括人口、经济、社会与环境的一个复杂巨系统。在对水资源的概念及其自然、经济和社会等属性综述的基础上,详细论述了水资源与水文循环、水量平衡结构、人口、经济、社会与环境等的相互关系,并以黄河流域水资源问题为例,说明目前阶段的水资源问题与人口、经济发展、社会与环境的联系愈加紧密。在上述分析的基础上,作者认为水资源承载力是刻画水资源与区域人口、经济、社会与环境复杂关系的一个很好的分析途径,并进一步明晰了水资源承载力的概念和研究方向。