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 #01 | Jan 14, 2010[Finished]
"Statistical population genetics and its application to fisheries population management"
Dr. Toshihide KITAKADO
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Most natural populations are spatially and/or temporally structured. For example, population subdivision can occur because of geographical isolation of populations, and its level depends on rates of migration, mutation and so on. Also, mixture of different subpopulations in migration corridors, feeding, and breeding grounds is one of possible structures observed in natural populations. Such mixing conditions can vary spatially across areas or temporally through years.
Of course, these population structures may give impact on the genetic compositions and variations of population. It does mean that, if genetic data from such populations can be observed, it may be possible to draw information on their population structures and important parameters. In this lecture, I will introduce some recent advances in statistical modeling and estimation for inferring the population structure based on genetic data. I also convey why such knowledge on the population structure plays a crucial role for better fisheries management.
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| #02 | Jan 19, 2010[Finished]
"Morphological quality of hatchery-raised juvenile fish: toward development of prevention method of malformed fish"
Dr. Yutaka HAGA
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The global food crisis issue is of concerned in the context of overpopulation, climate changes, and overconsumption of agriculture resources. Constant supply of food resources should be critically important to support an increasing population in the world. Aquaculture, probably the fastest growing food production sector, is now accounts for approximately 50% of seafood supply. World aquaculture production has increased tremendously during the last fifty years from less than a million tons in the early 1950's to 59.4 million tons by 2004 (FAO, 2005). To support increasing production of aquaculture, large numbers of juveniles have been produced in hatcheries. Hatchery-raised juveniles however often show skeletal deformities.
Skeletal deformity is now a serious concern in modern aquaculture industry and often observed in commercially important species. Skeletal deformity potentially occurs in all species and can be induced by various factors such as nutritional, environmental, and genetic factors. The morphology of deformed skeleton resembles each other even if it is induced by different factors. Recently, we developed new methodology to stain skeletons in live fish larvae by fluorescent chromophore. This method allows us to visualize skeletons in live fish larvae and enables early diagnosis of symptom of skeletal deformity in fish. In addition, developing models is another powerful strategy to better undestand mechanism of skeletal development of fish larvae. In human disease, mechanism of disease is examined in model animals. Mouse models currently available for genetic research include thousands of unique inbred strains and genetically engineered mutants that are prone to different cancers, diabetes, obesity, blindness, behavioral disease and even drug addiction. These model mice are powerful tool to test curative efficacy of various drug candidates and to understand molecular mechanism underlying the human disease. In contrast, morphological observation is the major approach for diagnosis of skeletal deformity of fish. We succeeded to develop transgenic zebrafish specifically express green fluorescent protein in intervertebral discs. Employing this model fish, we could visualize abnormal development of intervertebral discs in live zebrafish larvae. These results demonstrated that this transgenic zebrafish was a very useful tool to understand mechanism of developmental of vertebrae of fish. Future direction of studies on fish skeletal deformity in aquaculture will be discussed.
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| #03 | Jan 20, 2010[Finished]
"Mitigation measures for the incidental catch of endangered species in marine fisheries"
Dr. Daisuke SHIODE
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Incidental catch (bycatch) of endangered species is an important management issue in marine fisheries. In recent years, particular concerns regarding the interaction with sea turtles, sea birds, etc. as well as other species in the pelagic ecosystem have been expressed. In modern fisheries, co-existence within marine ecosystem is strongly required, and various mitigation measures have been developed for reducing incidental catches, such as turtle exclude device (TED) in trawl fishery, bird scaring lines (Tori-pole), blue-dyed bait, and the use of circle hook etc. in tuna longline fishery. In this lecture, I will introduce the structure, function, and effectiveness of these mitigation measures through the fishing gear technology including the background of development.
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| #04 | Jan 25, 2010[Finished]
"Quantitative epidemic analysis for fish diseases dynamics"
Dr. Masashi YOKOTA
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Although fish populations are damaged by many infectious diseases, it is insufficient to study from quantitative aspects. For avoiding epidemic risk, this matter must be investigated appropriately. The time scale for epidemic analysis is selected as an observation period of interest, without deep consideration. This lack of care has meant that the epidemic time scales of many historical diseases have not often synchronized with the demographic time scales of their hosts. Fundamental inferences about population dynamics are drawn from demographic parameters. Thus, these scale differences often cause unpredictable damage to host populations, like those of a sudden geological disaster, even when the biological and medical characteristics of the disease are known. The topics include examples of cohabitation experiments, field observations and numerical simulations, and reveals that the epidemic generation period is one of the most important parameters defining the ecology of an infectious disease. The generation-based observations constitute an essential step in the classification and risk management of a disease from the perspective of quantitative epidemiology.
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| #05 | Jan 26, 2010[Finished]
"Environment control and waste treatment technology in closed recirculating fish culture system "
Dr. Masato ENDO
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Closed recirculating fish culture system is one of the fish production facilities that has unique characteristics such as environment control, water reuse, and waste treatment. Hence, the use of this system for aquacultural production preserves the natural environment of the water and the fish resources. This lecture introduces the control of technology of the environmental factors, e.g., light, water temperature and salinity for growth enhancement and control of reproduction of the cultured fish in closed recirculating fish culture system. In addition, this system have the ability to collect wastes and sediment in the rearing water, therefore, removal of excreted waste from fish in the rearing water is an important issue since waste is a limiting factor for water reuse. In this lecture, technologies for waste reuse by plant and algae are explained.
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| #06 | Feb 01, 2010[Finished]
"Application of gene expression profiling for the investigation on the immunity of aquaculture animals"
Dr. Hideyoshi KONDO
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In intensive aquaculture systems, aquaculture animals are under threat of infectious diseases. The animals are therefore needed to exert their abilities known as "immunity" to combat against pathogenic microorganisms. In aquaculture systems, various methods to stimulate the immune mechanisms have been developed. A number of genes involved in such mechanisms have been identified so far. Recent advances in molecular biology enable us to characterize these genes in aquatic animals and evaluate how the molecules are involved in their immunity.
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| #07 | Feb 02, 2010[Finished]
"Drug metabolism and disposition in fish"
Dr. Kunihiko FUTAMI
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Recently, various problems concerning food safety have occurred. For example, a residue of antibacterial drugs was detected in imported farmed fish. In addition, unexpected contamination exists in farmed fish, even though the producers do not use any hazardous chemicals. This is the serious problem for risk management under the regulation of positive list system. It is important to understand the mechanisms of drug metabolism and disposition in fish. In this lecture, I will talk about 1) the basics of drug metabolism and disposition; 2) the role of drug metabolizing enzymes; 3) biomarkers for monitoring of pesticide residues in fish etc.
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| #08 | Feb 03, 2010[Finished]
"Probiotics for fish immunostimulant effect"
Dr. Takayuki Katagiri
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Probiotics in aquaculture is defined as a live microbial adjunct which has a beneficial effect on the host by modifying the host-associated or ambient microbial community.
We examined the histological effects of probiotic bacterium, Lactobacillus rhamnosus GG against Edwardsiella tarda and Aeromonas hydrophila as challenged in tilapia Oreochromis niloticus. Cumulative mortalities after challenged with both pathogens were significantly lower in probiotic-supplemented groups than in control group. In a histopathological survey of probiotic fish challenged separately with E. tarda and A. hydrophila, pyogranulomatous response was observed in head kidney and spleen during the early stage of infection. Furthermore, hemolysis in the probiotic group was observed milder compared with control group which signify the protective effects against hemolysin secreted by A. hydrophila. These observations strongly explain lower morality in probiotic- supplement groups with both pathogenic infections.
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Related Courses in the past |
Course in 2008 |
Course in 2007 |
Course in 2006 |
Course in 2005 |