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

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

Graphene thickness determination using reflection and contrast spectroscopy

10.1021/nl071254mNano Letters792758-276

FACTORS INFLUENCING BIOSECURITY ADOPTION ON LAYING HEN FARMERS

The present study was undertaken to identify factors that influences biosecurity adoption on laying hen farmers in Sidrap district, South Sulawesi. This district was choosen because beside it was famous as the center of laying hen farms, it was also as one of districts in South Sulawesi which suffered from Avian influenza outbreak. Total samples were 60 respondents. The samples were choosen through stratified random sampling from two subdistricts which had the most populous of layer smallholders, namely Baranti and Maritengngae. Data were obtained through observations and interviews using a questionnaire. Data were analyzed using a score based on biosecurity status. Biosecurity status was obtained based on the adoption of biosecurity measures which consisted of 9 stages: farm inputs, traffic onto farms, distance from sources of pathogens to shed, exposure of farm, biosecurity at farm boundary, biosecurity between farm boundary and shed, biosecurity at the shed door, traffic into the shed and susceptibility of the flock. Multiple regression model was employed to analyze the data. The study revealed that the adoption biosecurity were associated with gender, age, education, farming experience, farm-income, family size and social capital. These variables contributed 20% variation in biosecurity adoption of laying hen farms. However, only farm income, family size and social capital were the major factors influencing to the adoption of biosecurity (P<0.05)

High pressure photoluminescence and Raman studies of ZnxCd 1-xSe quantum dots

10.1088/0953-8984/20/32/325214Journal of Physics Condensed Matter2032-JCOM

Volume fraction, thickness, and permeability of the sealing layer in microbial self-healing concrete containing biogranules

Autonomous repair systems in construction materials have become a promising alternative to current unsustainable and labor-intensive maintenance methods. Biomineralization is a popular route that has been applied to enhance the self-healing capacity of concrete. Various axenic microbial cultures were coupled with protective carriers, and their combination appears to be useful for the development of healing agents for realizing self-healing concrete. The advantageous traits of non-axenic cultures, such as economic feasibility, self-protection, and high specific activity have been neglected so far, and thus the number of studies investigating their performance as healing agents is scarce. Here we present the self-healing performance of a mortar containing a healing agent consisting of non-axenic biogranules with a denitrifying core. Mortar specimens with a defined crack width of 400 μm were used in the experiments and treated with tap water for 28 days. Self-healing was quantified in terms of the crack volume reduction, the thickness of the sealing layer along the crack depth and water permeability under 0.1 bar pressure. Complete visual crack closure was achieved in the bio-based specimens in 28 days, the thickness of the calcite layer was recorded as 10 mm and the healed crack volume was detected as 6%. Upon self-sealing of the specimens, the water permeability decreased by 83%. Overall, non-axenic biogranules with a denitrifying core shows great potential for development of self-healing bioconcrete.Materials and Environmen