19 research outputs found

    Biology, Fishery, Conservation and Management of Indian Ocean Tuna Fisheries

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    The focus of the study is to explore the recent trend of the world tuna fishery with special reference to the Indian Ocean tuna fisheries and its conservation and sustainable management. In the Indian Ocean, tuna catches have increased rapidly from about 179959 t in 1980 to about 832246 t in 1995. They have continued to increase up to 2005; the catch that year was 1201465 t, forming about 26% of the world catch. Since 2006 onwards there has been a decline in the volume of catches and in 2008 the catch was only 913625 t. The Principal species caught in the Indian Ocean are skipjack and yellowfin. Western Indian Ocean contributed 78.2% and eastern Indian Ocean 21.8% of the total tuna production from the Indian Ocean. The Indian Ocean stock is currently overfished and IOTC has made some recommendations for management regulations aimed at sustaining the tuna stock. Fishing operations can cause ecological impacts of different types: by catches, damage of the habitat, mortalities caused by lost or discarded gear, pollution, generation of marine debris, etc. Periodic reassessment of the tuna potential is also required with adequate inputs from exploratory surveys as well as commercial landings and this may prevent any unsustainable trends in the development of the tuna fishing industry in the Indian Ocean

    Are dopa-responsive dystonia and Parkinson's s disease related disorders? A case report

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    L-Dopa-responsive dystonia (DRD) is a hereditary dystonia characterized by an excellent response to low dosages of levodopa. DRD patients may also develop Parkinsonism which resembles idiopathic Parkinson's disease. In classical DRD no changes in the dopaminergic uptake have been observed.A 65-year old woman presented with clinically remarkably slowly progressing Parkinson's disease (PD) without any dystonic signs and excellent response to dopaminergic medications. We obtained a [(123)I] FP-CIT-SPECT (DaTSCAN™) in order to elucidate a striatal dopaminergic deficit.We found a reduced uptake in the [(123)I] FP-CIT-SPECT (DaTSCAN™) contralateral to the more affected body side. Additionally, the patient showed a heterozygous deletion of the GHC1 gene.Patients with mild parkinsonian symptoms, excellent response to low dosages of dopaminergic drugs and a reduced dopamine-transporter uptake in [(123)I] FP-CIT-SPECT might more commonly be GCH1 mutation carriers than has previously been supposed. PD patients with a positive family history of DRD and combination of these clinical symptoms should be offered genetic counselling and testing for GCH1

    Use of soft computing techniques in renewable energy hydrogen hybrid systems

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    Soft computing techniques are important tools that significantly improve the performance of energy systems. This chapter reviews their many contributions to renewable energy hydrogen hybrid systems, namely those systems that consist of different technologies (photovoltaic and wind, electrolyzers, fuel cells, hydrogen storage, piping, thermal and electrical/electronic control systems) capable as a whole of converting solar energy, storing it as chemical energy (in the form of hydrogen) and turning it back into electrical and thermal energy. Fuzzy logic decision-making methodologies can be applied to select amongst renewable energy alternative or to vary a dump load for regulating wind turbine speed or find the maximum power point available from arrays of photovoltaic modules. Dynamic fuzzy logic controllers can furthermore be utilized to coordinate the flow of hydrogen to fuel cells or employed for frequency control in micro- grid power systems. Neural networks are implemented to model, design and control renewable energy systems and to estimate climatic data such as solar irradiance and wind speeds. They have been demonstrated to predict with good accuracy system power usage and status at any point of time. Neural controls can also help in the minimization of energy production costs by optimal scheduling of power units. Genetic or evolutionary algorithms are able to provide approximate solutions to several complex tasks with high number of variables and non-linearities, like optimal operational strategy of a grid-parallel fuel cell power plant, optimization of control strategies for stand-alone renewable systems and sizing of photovoltaic systems. Particle swarm optimization techniques are applied to find optimal sizing of system components in an effort to minimize costs or coping with system failures to improve service quality. These techniques can also be implemented together to exploit their potential synergies while, at the same time, coping with their possible limitations. This chapter covers soft computing methods applied to renewable energy hybrid hydrogen systems by providing a description of their single or mixed implementation and relevance, together with a discussion of advantages and/or disadvantages in their applications. \uc2\ua9 Springer-Verlag Berlin Heidelberg 2011

    Are anaesthetics toxic to the brain?

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    It has been assumed that anaesthetics have minimal or no persistent effects after emergence from anaesthesia. However, general anaesthetics act on multiple ion channels, receptors, and cell signalling systems in the central nervous system to produce anaesthesia, so it should come as no surprise that they also have non-anaesthetic actions that range from beneficial to detrimental. Accumulating evidence is forcing the anaesthesia community to question the safety of general anaesthesia at the extremes of age. Preclinical data suggest that inhaled anaesthetics can have profound and long-lasting effects during key neurodevelopmental periods in neonatal animals by increasing neuronal cell death (apoptosis) and reducing neurogenesis. Clinical data remain conflicting on the significance of these laboratory data to the paediatric population. At the opposite extreme in age, elderly patients are recognized to be at an increased risk of postoperative cognitive dysfunction (POCD) with a well-recognized decline in cognitive function after surgery. The underlying mechanisms and the contribution of anaesthesia in particular to POCD remain unclear. Laboratory models suggest anaesthetic interactions with neurodegenerative mechanisms, such as those linked to the onset and progression of Alzheimer's disease, but their clinical relevance remains inconclusive. Prospective randomized clinical trials are underway to address the clinical significance of these findings, but there are major challenges in designing, executing, and interpreting such trials. It is unlikely that definitive clinical studies absolving general anaesthetics of neurotoxicity will become available in the near future, requiring clinicians to use careful judgement when using these profound neurodepressants in vulnerable patients
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