40 resultados para Biology, Microbiology|Biology, Bioinformatics|Biology, Virology|Computer Science


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Microorganisms distributed in the marine and brackish environments play an important role in the decomposition of organic matter and mineralisation in the system (Seshadri and lgnacimuthu, 2002). Estuary is one of the most productive ecosystems, at the same time one among the least explored ecosystems on earth, which has immense potential as a source of potent microorganisms that produce valuable compounds particularly, enzymes such as proteases. In this scenario, it is very appropriate to embark on finding novel alkaline protease producers from the estuarine system. The area where the present investigation was carried out is a part of the extensive estuarine system of South India viz. Cochin Estuary. There is meagre knowledge regarding the microbial composition, particularly the protease producers of Cochin Estuary. Hence, the present study has been undertaken with the objective of finding novel alkaline protease producing bacteria from Cochin Estuary

Relevância:

100.00% 100.00%

Publicador:

Resumo:

About 80 years ago, the neurosecretory eyestalk structures and their role in endocrine regulation was recognized in crustaceans. After the recognition it took half a century to identify the first peptide hormone. Till date a large number of homologous peptides of crustacean hyperglycaemic hormone and moult-inhibiting hormone have been identified, consequently they are called the CHH family hormones. This family comprises of highly multifunctional peptides which according to sequences and precursor structures can be divided into two subfamilies, type-I (CHH/ITP) and II (MIH, MOIH, VIH/GIH) (Webster et al., 2012). The XO-SG complex has been the major site of the two subfamilies. The advent of molecular techniques resulted in the characterization of different precursors of CHH, MIH and GIH; these hormones consist of a signal peptide, but only the preprohormone of CHHs contain a precursor- related peptide (CPRP) located between the signal and the mature hormone (Weidemann et al., 1989; Klein et al., 1993b; De Kleijn and Van Herp, 1995). The essentialities of the gene structure comply with the functions of the CHH family hormones. The CHH family hormone functions are inhibitory as well as stimulatory in the process of reproduction and maturation

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Poisoning by pesticides from agricultural fields is a serious water pollution problem and its environmental long-term effect may result in the incidence of poisoning of fish and other aquatic life forms (jyothi and Narayan, 1999). Fishes like Heteropneustesfbssilis and C/arius batrac/nus are especially prone to serious pesticide pollution as their habitat is mostly the agriculture area. Though only few studies are conducted in this area, it can be assessed from the local information that, population of such fish is on the verge of vulnerability due to extensive use of pesticides. The knowledge of sublethal effects of xenobiotic compounds on hematological parameters, enzyme activities and metabolite concentrations is very important to delineate the fish health status and provide a future understanding of ecological impacts. These pesticides act by causing inhibition of cholinesterase enzymes (ChE) by formation of enzyme inhibitor complex (O'Brien, 1976) and damaging the nervous system. These effects may result in metabolic disorders. Associated to cholinesterase activities, a study of other enzymes such as phosphatases and aminotransferases close to intermediary metabolite determination provides a wider view of metabolism. Interest in toxicological aspects has grown in recent years and research is now increasingly focused on mechanistic aspects of oxidative damage and cellular responses in biological system. The term ‘biomarker’ is generally used in a broad sense to include almost any measurement reflecting an interaction between a biological system and a potential hazard, which may be chemical, physical or biological (WHO, 1993). As biomarker stands for immediate responses, they are used as early warning signals of biological effects caused by environmental pollutants. The present work attempts to assess the toxicity of organophosphorus insecticide monocrotophos on the experimental organism selected for this study namely stinging catfish (Heteropneustesfossi/is) (Bloch), and to probe into the stress responses of the organism

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fishes are one of the most important members of the aquatic food chain, and through them some toxicants may reach human beings as well. The selection of organisms for toxicity test is mainly based on certain criteria like its ecological status, position within the food chain, suitability for laboratory studies, genetically stable, uniform populations and adequate background data on the organism (Buikema et al., 1982). The species selected for the present study Etroplus maculatus satisfy most of the above protocols. Rechten (1980) opined it as a laboratory favorite of fish researchers. However, there are difficulties in the rise of fishes for pollution assessment impact. Most important of these is our limited understanding of the mechanism of toxicity. The interpretation of the significance or specificity of a measured biological response could there for become difficult. Not withstanding these limitations, attempts have been made to the normal haematology and to analyze the impact of heavy metal at realistic levels to the experimental media, on the haematology, and enzymatic activity and histology of Etroplus maculatus

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The main objective of the present work is to acquire information regarding the growth responses of P. monodon larvae (from PZ1 upto PL1) to various mono specific and mixed diets. Evaluate the nutritional quality of selected species of micro algae viz. Chaetoceros calcitrans, Dunaliella salina, Isochrysis galbana and Nannochloropsis salina, larvae at three cell concentrations 10x104 cells/ml, 25x104 cells/ml and 50x104 cells/ml. The P. monodon larvae were transported, at the Nauplius stage, to the laboratory. The larvae were stocked at density of 150 larvae per litre in 5 litre FRP tanks with 3 litres of sea water. The algal cell density given to the larvae varied. The larval stages were fed with increasing densities of algae to evaluate the relationship between the food densities, ingestion rates, development and growth of the larvae. The water quality parameters, the percentage of survival rate, the growth estimation and the algal cell count were done. Each experiment was carried out in triplicate with a control group of larvae fed with Chaetoceros calcitrans. For the estimation standard procedures were used.to P. monodon

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present work is focused on the organelle and biochemical responses to heavy metal exposure in the fish Oreochromis mossambicus giving particular importance to the metal detoxifying machinery of the organism. The thesis is an outcome of the effort aimed at developing practicable monitoring techniques to deliver guidelines for biological effect monitoring and the need for specific biochemical methods to detect biological effects of heavy metals that can be interpreted in terms of the health status of the individual organism and eventually alterations in vital processes as growth and reproduction. The efficiency of the metal detoxifying metallothioneins which is an attractive tool for biological monitoring, their role as scavengers of trace metal ions and thus in relieving the biological machinery from their toxicity effects are important themes of this study. Efforts have also been made to test the reliability of the spill over hypothesis of the action of metallothioneins (Winge et a1.,1973) and their use as a biological barometer of heavy metal stress.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the present study an endeavour has been made to analyse the acute toxicity of WAFs of Bombay High crude and Light Diesel oil on commercially important bivalve species Perna viridis and Perna indica by static bioassay methods. The toxic effects of chemicals in the WAF on the organisms ; their tissues and eventually on rate functions have been elucidated. Marine oil pollution not only affects productivity and quality of marine organisms but also eventually affects the health of human population due to a possible health risk by way of consumption of oil contaminated seafood

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Modern computer systems are plagued with stability and security problems: applications lose data, web servers are hacked, and systems crash under heavy load. Many of these problems or anomalies arise from rare program behavior caused by attacks or errors. A substantial percentage of the web-based attacks are due to buffer overflows. Many methods have been devised to detect and prevent anomalous situations that arise from buffer overflows. The current state-of-art of anomaly detection systems is relatively primitive and mainly depend on static code checking to take care of buffer overflow attacks. For protection, Stack Guards and I-leap Guards are also used in wide varieties.This dissertation proposes an anomaly detection system, based on frequencies of system calls in the system call trace. System call traces represented as frequency sequences are profiled using sequence sets. A sequence set is identified by the starting sequence and frequencies of specific system calls. The deviations of the current input sequence from the corresponding normal profile in the frequency pattern of system calls is computed and expressed as an anomaly score. A simple Bayesian model is used for an accurate detection.Experimental results are reported which show that frequency of system calls represented using sequence sets, captures the normal behavior of programs under normal conditions of usage. This captured behavior allows the system to detect anomalies with a low rate of false positives. Data are presented which show that Bayesian Network on frequency variations responds effectively to induced buffer overflows. It can also help administrators to detect deviations in program flow introduced due to errors.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis Entitled Journal productivity in fishery science an informetric analysis.The analyses and formulating results of the study, the format of the thesis was determined. The thesis is divided into different chapters mentioned below. Chapter 1 gives an overview on the topic of research. Introduction gives the relevance of topic, define the problem, objectives of the study, hypothesis, methods of data collection, analysis and layout of the thesis. Chapter 2 provides a detailed account of the subject Fishery science and its development. A comprehensive outline is given along with definition, scope, classification, development and sources of information.Method of study used in this research and its literature review form the content of this chapter. Chapter 4 Details of the method adopted for collecting samples for the study, data collection and organization of the data are given. The methods are based on availability of data, period and objectives of the research undertaken.The description, analyses and the results of the study are covered in this chapter.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Information communication technology (IC T) has invariably brought about fundamental changes in the way in which libraries gather. preserve and disseminate information. The study was carried out with an aim to estimate and compare the information seeking behaviour (ISB) of the academics of two prominent universities of Kerala in the context of advancements achieved through ICT. The study was motivated by the fast changing scenario of libraries with the proliferation of many high tech products and services. The main purpose of the study was to identify the chief source of information of the academics, and also to examine academics preference upon the form and format of information source. The study also tries to estimate the adequacy of the resources and services currently provided by the libraries.The questionnaire was the central instrument for data collection. An almost census method was adopted for data collection engaging various methods and tools for eliciting data.The total population of the study was 957, out of which questionnaire was distributed to 859 academics. 646 academics responded to the survey, of which 564 of them were sound responses. Data was coded and analysed using Statistical Package for Social Sciences (SPSS) software and also with the help of Microsofl Excel package. Various statistical techniques were engaged to analyse data. A paradigm shift is evident by the fact that academies push themselves towards information in internet i.e. they prefer electronic source to traditional source and the very shift is coupled itself with e-seeking of information. The study reveals that ISB of the academics is influenced priman'ly by personal factors and comparative analysis shows that the ISB ofthc academics is similar in both universities. The productivity of the academics was tested to dig up any relation with respect to their ISB, and it is found that productivity of the academics is extensively related with their ISB. Study also reveals that the users ofthe library are satisfied with the services provided but not with the sources and in conjunction, study also recommends ways and means to improve the existing library system.