| Abstract: | The primary focus of this study was to asses the impact of selected antecedent variables namely Psychological Empowerment at Work (PEW), Psychological Contract Violation (PCV), Work Life Balance (WLB), Job Satisfaction (JS) and Affective Organisational Commitment (AOC) on Managerial Performance (MP) of middle level managers of private sector manufacturing and service sector organisations in Kerala.The study brings out the significance of Job Attitudes namely Job Satisfaction and Affective Organisational Commitment in meaningfully explaining the linkage between the rest of the antecedent variables in the study and Managerial Performance. The study interestingly revealed that Job Attitudes play a mediating role in explaining performance of managers unlike visualised in the initial conceptual framework. The study points to the importance of taking care of job attitudes in the work place to ensure performance of managers. The result of the study also brings out the significance of maintaining work-life balance especially in service sector organisations because it will have a direct impact on the level of performance of managers than most of the other contextual factors. Hence, it is the responsibility of HR department to initiate activities which are customised to the collective aspirations of the members of respective organisations to ensure positive job attitudes. HR departments should advice and convince the top management to provide resource support and endorsement to such initiatives. |
| URI: | http://dyuthi.cusat.ac.in/purl/4976 |
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| Dyuthi-T2047.pdf | (4.132Mb) |
| Abstract: | White spot syndrome virus (WSSV) is the deadliest virus among crustaceans ever discovered having several unique and novel features. Recent developments in genomics and proteomics could elucidate the molecular process involved in the WSSV infection and the host pathogen interaction to some extent. Until now no fool proof treatment or prophylactic measure has been made available to control WSSV out breaks in culture system. Even though there are technologies like application of immunostimulants, vaccines, RNAi and several antiviral natural products none of them has been taken to the level of clinical trials. However, there are several management options such as application of bioremediation technologies to maintain the required environmental quality, maintenance of zero water exchange systems coupled with application of probiotics and vaccines which on adoption shall pave way for successful crops amidst the rapid spread of the virus. In this context the present work was undertaken to develop a drug from mangrove plants for protecting shrimp from WSSV.Mangroves belong to those ecosystems that are presently under the threat of destruction, diversion and blatant attack in the name of so called ‘developmental activities’. Mangrove plants have unique ecological features as it serves as an ecotone between marine and terrestrial ecosystem and hence possess diversity of metabolites with diverse activities. This prompted them being used as remedial measures for several ailments for ages. Among the mangrove plants Ceriops tagal, belonging to the family Rhizophororaceae was in attention for many years for isolating new metabolites such as triterpenes, phenolic compounds, etc. Even though there were attempts to study various plant extracts to develop anti-viral preparations their activity against WSSV was not investigated as yet. |
| Description: | Dept.of Marine Biology,Microbiology and Biochemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3004 |
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| Dyuthi-T0984.pdf | (4.664Mb) |
| Abstract: | Thermoelectric materials are revisited for various applications including power generation. The direct conversion of temperature differences into electric voltage and vice versa is known as thermoelectric effect. Possible applications of thermoelectric materials are in eco-friendly refrigeration, electric power generation from waste heat, infrared sensors, temperature controlled-seats and portable picnic coolers. Thermoelectric materials are also extensively researched upon as an alternative to compression based refrigeration. This utilizes the principle of Peltier cooling. The performance characteristic of a thermoelectric material, termed as figure of merit (ZT) is a function of several transport coefficients such as electrical conductivity (σ), thermal conductivity (κ) and Seebeck coefficient of the material (S). ZT is expressed asκσTZTS2=, where T is the temperature in degree absolute. A large value of Seebeck coefficient, high electrical conductivity and low thermal conductivity are necessary to realize a high performance thermoelectric material. The best known thermoelectric materials are phonon-glass electron – crystal (PGEC) system where the phonons are scattered within the unit cell by the rattling structure and electrons are scattered less as in crystals to obtain a high electrical conductivity. A survey of literature reveals that correlated semiconductors and Kondo insulators containing rare earth or transition metal ions are found to be potential thermoelectric materials. The structural magnetic and charge transport properties in manganese oxides having the general formula of RE1−xAExMnO3 (RE = rare earth, AE= Ca, Sr, Ba) are solely determined by the mixed valence (3+/4+) state of Mn ions. In strongly correlated electron systems, magnetism and charge transport properties are strongly correlated. Within the area of strongly correlated electron systems the study of manganese oxides, widely known as manganites exhibit unique magneto electric transport properties, is an active area of research.Strongly correlated systems like perovskite manganites, characterized by their narrow localized band and hoping conduction, were found to be good candidates for thermoelectric applications. Manganites represent a highly correlated electron system and exhibit a variety of phenomena such as charge, orbital and magnetic ordering, colossal magneto resistance and Jahn-Teller effect. The strong inter-dependence between the magnetic order parameters and the transport coefficients in manganites has generated much research interest in the thermoelectric properties of manganites. Here, large thermal motion or rattling of rare earth atoms with localized magnetic moments is believed to be responsible for low thermal conductivity of these compounds. The 4f levels in these compounds, lying near the Fermi energy, create large density of states at the Fermi level and hence they are likely to exhibit a fairly large value of Seebeck coefficient. |
| URI: | http://dyuthi.cusat.ac.in/purl/5068 |
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| Dyuthi-T 2132.pdf | (6.138Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5450 |
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| 1.Abstract.pdf | (610.5Kb) |
| 10.Ref.pdf | (636.9Kb) |
| 2.Chapter 1 .pdf | (553.8Kb) |
| 3.Chapter 2 .pdf | (577.3Kb) |
| 4.Chapterv...3.pdf | (506.7Kb) |
| 5.Chapterv...4 .pdf | (652.3Kb) |
| 6.Chapterv......5 .pdf | (940.7Kb) |
| 7.Chapterv............6 .pdf | (839.6Kb) |
| 8.Chapterv............7 .pdf | (880.8Kb) |
| 9.Chapterv............8 .pdf | (391.7Kb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1662 |
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| Dyuthi-T0198.pdf | (1.136Mb) |
| Abstract: | Aquaculture is a form of agriculture that involves the propagation, cultivation and marketing of aquatic plants and animals in a controlled environment (Swann, 1992). After growing steadily, particularly in the last four decades, aquaculture is for the first time set to contribute half of the fish consumed by the human population worldwide. Given the projected population growth over the next two decades, it is estimated that at least an additional 40 million tonnes of aquatic food will be required by 2030 to maintain the current per capita consumption (FAO, 2006). Capture fisheries and aquaculture supplied the world with about 110 million tonnes of food fish in 2006. Of this total, aquaculture accounted for 47 percent (FAO, 2009). Globally, penaeid shrimp culture ranks sixth in terms of quantity and second in terms of value amongst all taxonomic groups of aquatic animals cultivated (FAO, 2006). In places where warm-water aquaculture was possible black tiger shrimp, Penaeus monodon became the preferred variety of shrimp cultivar owing to its fast growth, seed availability and importantly due to high prices it fetches (Pechmanee, 1997). World shrimp production is dominated by P.monodon, which accounted for more than 50 % of the production in 1999 (FAO, 2000). In the last few years the whiteleg shrimp, Litopenaeus vannamei, has replaced P.monodon in many countries. Indian shrimp culture is dominated by P.monodon with the East Coast accounting for 70% of the production (Hein, 2002). Intensive culture, apart from other problems, results in enhanced susceptibility of the cultured species to diseases (Jory, 1997), which in fact have become the biggest constraint in shrimp aquaculture (FAO, 2003). |
| Description: | National Centre for Aquatic Animal Health |
| URI: | http://dyuthi.cusat.ac.in/purl/3713 |
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| Dyuthi-T1670.pdf | (2.037Mb) |
| Abstract: | This thesis Entitled Marine actinomycetes as source of antimicrobial compounds and as probiotics and single cell protein for application in penaeid peawn culture systems. Ocean harbours more than 80% of all life on earth and remains our greatest untapped natural resource. The study revealed the potential of marine actinomycetes as a source of antimicrobial compounds. The selected streptomycetes were found to be capable of inhibiting most of the pathogenic vibrios, whichis a major problem both in hatcheries and grow out systems. The bioactive principle can be incorporated with commercial feeds and applied as medicated diet for the control of vibrios in culture systems.The hydrolytic potential inhibitory property against pathogens and non—pathogenicity to penaeid prawns make the selected Streptomycesspp.an effective probioic in aquaculture. Since there is considerably less inhibition to the natural in pond ecosystem the microbial diversityis being maintained and thereby the water quality. Actinomycetes was found to be a good source of single cell protein as an ingredient inaquaculture feed formulations. Large amount of mycelial waste (actinomycete biomassO is produced from antibiotic industries and this nutrient rich waste can be effectively used as a protein source in aquaculture feeds.This study reveals the importance of marine actinomycetes as a source of antimicrobial compounds and as a probiotic and single cell protein for aquaculture applications. |
| Description: | School of Marine Science, Division of marine biology, microbiology and biochemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3043 |
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| Dyuthi-T1017.pdf | (3.657Mb) |
| Abstract: | The present study revealed the importance of marine actinomycetes as a potent source of bio active secondary metabolites. The selected isolates were capable of protecting Peaneus monodon against WSSV infection. They also proved to be inhibitory to vibrios and is a rich pool of hydrolytic enzymes. Their capacity to proliferate in saline environments and their property of non-pathogenicity to prawns makes them good candidates to be applied as probionts in penaeid shrimp aquaculture. They also enhanced the immune status of shrimps challenged with WSSV and act as a good source of antioxidants. Exploitation of the potential for the prophylactic and therapeutic measures in aquatic animal health management would be highly rewarding. This work is a preliminary study targeting marine actinomycetes as a source of antiviral compounds and as probionts in Penaeus monodon culture systems. More work is needed to understand the nature and mode of action of the bioactive compound, the various aspects of immune and antioxidant responses under challenge and when exposed to pro active treatments, and the dose and frequency of application of such compounds under rearing conditions. |
| Description: | Department of Marine Biology, Microbiology & Biochemistry,Cochin University of Science & Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2822 |
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| Dyuthi-T0842.pdf | (10.28Mb) |
| Description: | Department of Marine Biology,Microbiology and Biochemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2789 |
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| Dyuthi-T0810.pdf | (9.286Mb) |
| Abstract: | Aquaculture has developed rapidly over the last three decades to become an important activity worldwide.The Food and Agricultural Organization (FAO) of the UN acknowledge that global fishery output must be increased by at least 50% to offset projected shortfalls in dietary protein by 2030.LAquaculture has developed rapidly over the last three decades and has become an importat industry as today’s demand for fish exceeds the natural supply.lmmunostimulants are chemical compounds that activate the immune system of animals and render them more resistant to infections by viruses, bacteria, fungi, and parasites. lmmunostimulants have been obtained from diverse natural sources where, microbial cell wall acts as the main source.The salient findings of the study are summariseSeven marine yeasts were screened for growth promoting and immunostimulant property in F. indicus. Candida sake S165 was found to be best in terms of its support for growth and protection against white spot virus infection.The study revealed that marine yeast Candida sake can be effectively used as potential source of immunostimulants for application in penaeid prawns culture systems. The study emphasise the fact that the dose and frequency of application of immunostimulants are to be standardised and validated before commercialisation to achieve optimum stimulation of the immune system and to avoid immune fatigue die to verdose.Marine yeast (whole cell) was found to support better immunostimulation compared to its cell wall component B-1,3-glucan. This study shows that administration of marine yeast (whole cell) or B-1,3-glucan as immunostimulants in aquaculture would definitely help in protection of the stock to a few more days even though total protection is not being imparted. This partial protection itself would be highly helpful to the farming industry so that they can get sufficient time to plan for a safe harvest and save the crop from cent percent mortality. |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3110 |
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| Dyuthi-T1084.pdf | (6.001Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5333 |
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| Dyuthi T-2400.pdf | (8.371Mb) |
| Abstract: | Indian marine engineers are renowned for employment globally due to their knowledge, skill and reliability. This praiseworthy status has been achieved mainly due to the systematic training imparted to marine engineering cadets. However, in an era of advancing technology, marine engineering training has to remain dynamic to imbibe latest technology as well as to meet the demands of the shipping industry. New subjects of studies have to be included in the curriculum in a timely manner taking into consideration the industry requirements and best practices in shipping. Technical competence of marine engineers also has to be subjected to changes depending upon the needs of the ever growing and over regulated shipping industry. Besides. certain soft skills are to be developed and improved amongst the marine engineers in order to alter or amend the personality traits leading to their career success.If timely corrective action is taken. Indian marine engineers can be in still greater demand for employment in global maritime field. In order to enhance the employability of our mmine engineers by improving their quality, a study of marine engineers in general and class IV marine engineers in particular was conducted based on three distinct surveys, viz., survey among senior marine engineers, survey among employers of marine engineers and survey of class IV marine engineers themselves.The surveys have been planned and questionnaires have been designed to focus the study of marine engineer officer class IV from the point of view of the three distinct groups of maritime personnels. As a result of this, the strength and weakness of class IV marine engineers are identified with regard to their performance on board ships, acquisition of necessary technical skills. employability and career success. The criteria of essential qualities of a marine engineer are classified as academic, technical, social, psychological. physical, mental, emergency responsive, communicative and leadership, and have been assessed for a practicing marine engineer by statistical analysis of data collected from surveys. These are assessed for class IV marine engineers from the point of view of senior marine engineers and employers separately. The Endings are delineated and graphically depicted in this thesis.Besides. six pertinent personality traits of a marine engineer viz. self esteem. learning style. decision making. motivation. team work and listening self inventory have been subjected to study and their correlation with career success have been established wherever possible. This is carried out to develop a theoretical framework to understand what leads a marine engineer to his career attainment. This enables the author to estimate the personality strengths and weaknesses of a serving marine engineer and eventually to deduce possible corrective measures or modifications in marine engineering training in India.Maritime training is largely based on International Conventions on Standard of Training. Certification and Watch keeping for Seafarers 1995. its associated Code and Merchant Shipping (STCW for Seafarers) Rules 1998. Further, Maritime Education, Training and Assessment (META) Manual was subjected to a critical scrutiny and relevant Endings of thc surveys arc superimposed on the existing rule requirement and curriculum. Views of senior marine engineers and executives of various shipping companies are taken into account before arriving at the revision of syllabus of marine engineering courses. Modifications in the pattern of workshop and sea service for graduate mechanical engineering trainees are recommended. Desirable age brackets of junior engineers and chief engineers. use of Training and Assessment Record book (TAR Book) during training etc. have also been evaluated.As a result of the pedagogic introspection of the existing system of marine engineering training in India. in this thesis, a revised pattern of workshop training of six months duration for graduate mechanical engineers. revised pattern of sea service training of one year duration and modified now diagram incorporating the above have been arrived at. Effects of various personality traits on career success have been established along with certain findings for improvement of desirable personality traits of marine engineers. |
| Description: | Department of Ship Technology, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2680 |
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| Dyuthi-T0732.pdf | (5.596Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5335 |
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| Dyuthi T-2402.pdf | (10.41Mb) |
| Abstract: | As the title of the thesis indicates, a detailed analysis of microalgae, the major primary producers and the first link in aquatic food chains, was carried out during this study. Microalgae are either planktonic or benthic. The studies on these microscopic autotrophs are having an upsurge of interest recently due to their variations, adaptations, short generation time and various utilitarian aspects, including food, fodder and fuel. The surface water samples collected during the cruises (cruise nos. 189, 193, 195, 196, 203, 204, 205, 207 and 209) of Fisheries and Oceanographic Research Vessel (FORV) Sagar Sampada (Fig.2.2), conducted during the period from November 2000 to November 2002, are used as samples for microalgal estimation in the EEZ of India. The present research work includes the identification and distributional pattern of planktonic microalgae in the EEZ of India. The blooms encountered during the above mentioned cruises of FORV Sagar Sampada and the blooms of Kerala coast during the period from 2001-2005 are also studied |
| Description: | Department of Marine Biology, Microbiology and Biochemistry School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3259 |
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| Dyuthi-T1233.pdf | (7.433Mb) |
| Abstract: | Marine yeast have been regarded as safe and showing a beneficial impact on biotechnological process. It provides better nutritional and dietary values indicating their potential application as feed supplements in aquaculture. Brown et al. (1996) evaluated all the marine yeasts characterised with high protein content, carbohydrate, good amino acid composition and high levels of saturated fats. However, there is paucity of information on marine yeasts as feed supplements and no feed formulation has been found either in literature or in market supplemented with them. This statement supported by Zhenming et al. (2006) reported still a lack of feed composed of single cell protein (SCP) from marine yeasts with high content of protein and other nutrients. Recent research has shown that marine yeasts also have highly potential uses in food, feed, medical and biofuel industries as well as marine biotechnology (Chi et al., 2009; 2010). Sajeevan et al. (2006; 2009a) and Sarlin and Philip (2011) demonstrates that the marine yeasts Candida sake served as a high quality, inexpensive nutrient source and it had proven immunostimulatory properties for cultured shrimps. This strain has been made part of the culture collection of National Centre for Aquatic Animal Health, Cochin University of Science and Technology as Candida MCCF 101. Over the years marine yeasts have been gaining increased attention in animal feed industry due to their nutritional value and immune boosting property.Therefore, the present study was undertaken, and focused on the nutritional quality, optimization of large scale production and evaluation of its protective effect on Koi carp from Aeromonas infection |
| Description: | National Centre for Aquatic Animal Health School of Environmental Studies Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/4742 |
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| Dyuthi-T1840.pdf | (5.740Mb) |
| Abstract: | the present study was undertaken with the following objectives: 1. Isolation and identification of yeasts from Arabian Sea and Bay of Bengal. 2. Molecular characterization of yeast isolates and phylogenetic analysis 3. Physiological and biochemical characterization of the isolates. 4. Proximate composition of yeast biomass and bioactive compounds. The Thesis is comprised of six chapters. A general introduction to the topic is given in Chapter1. Isolation and identification of marine yeasts are presented in Chapter 2. Chapter 3 deals with molecular identification and physiological characterization of Non- pigmented yeasts. Molecular identification and physiological characterization of pigmented yeast is presented in Chapter 4. Proximate composition of yeast biomass of various genera and their bioactive compounds are illustrated in Chapter 5. A summary of the results of the present study is given in Chapter 6. References and Appendices are followed |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3689 |
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| Dyuthi-T1655.pdf | (6.616Mb) |
| Abstract: | The study revealed the potential of marine yeasts as a source of single cell protein and immunostimulant for prawns. Prawns fed with the selected marine yeasts were showing more growth compared to the control feed and commercial feed. Yeasts being rich with proteins, vitamins and carbohydrates serve as a growth promoter for prawns as being evidenced in this study. The better performance of marine yeasts, D. hansenii S8 and S100 and C. tropicalis S186 compared to S. cerevisiae S36 as a feed supplement is worth investigating. Besides being a rich nutritional source, yeasts act as immunostimulants by virtue of its high carbohydrate (Beta, 1-3 glucan) and RNA content. Beta, 1-3 glucan, a cell wall component of yeasts /fungi is the most commonly used immunostimulant in aquaculture. The present study shows that even the whole cell yeast could serve as a good immunostimulant when supplied through diet. Extraction of Beta-1,3 glucan results in the removal of nutrients like proteins, vitamins etc. from the cell biomass.Utilization of the yeast biomass as such in the diet would help perform a dual role as nutritional component and immunostimulant for aquaculture applications. |
| Description: | Dept.of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2273 |
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| Dyuthi-T0580.pdf | (10.61Mb) |
| Abstract: | The present study provides an account of the occurrence and diversity of marine yeasts in the slope sediments of Arabian Sea and Bay of Bengal. It also gives a clear idea about the role of yeasts in the benthic realm of marine ecosystem. The lipolytic potential of the organisms indicate the presence of rich lipid moieties in the study area. The isolates, Candida sp. SD 302 and Pichia guilliermondii SD 337 were proved to have potential oil degrading property and can be employed as bioremediators of oil spill after further characterization. The black yeasts isolated during the study area were found to have high commercial value by virtue of the by-products obtained from them. The melanin and the melanin degrading enzyme extracted from these organisms are potential bioactive materials for application in cosmetology. |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/xmlui/purl/1935 |
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| Dyuthi-T0427.pdf | (20.16Mb) |
| URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1626 |
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| Dyuthi-T0176.pdf | (2.977Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5488 |
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| Dyuthi T-2531.pdf | (11.61Mb) |
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