327 research outputs found
The role of fisheries sector in the coastal fishing communities of Sri Lanka
Sri Lanka is an island country with a land area of 65 610 km2. With the declaration of the exclusive economic zone (EEZ) in 1976, the country gained sovereign rights over an ocean area of 536 000 km2 and EEZ extending from 24 to 200 nm. The continental shelf is about 26 000 km2 with an average width of around 22 km, and the coastline is 1 100 km long. The total annual fish production of Sri Lanka was 25 000 t in 1952 and 269 850 t in 1998. Major fish species caught in Sri Lankan waters are skipjack, blood fish, yellow fin tuna, mullet, shark, trevally, Spanish mackerel, prawns, lobsters. Gross domestic product (GDP) is composed of services, agriculture including forestry and fishery, manufacturing, construction and mining and quarrying. Of these, the agriculture sector contributed 21% with 2.5% coming from the fisheries subsector in 1998. In 1975, fisheries contributed Rs420 million to GDP and substantially improved to Rs24 823 million (US = 64.90 Sri Lanka Rupee; source: oanda.com) in 1998. Export volume from fisheries was 3 240 t in 1985, and 11 433 t in 1998; equivalent to an export value of Rs453 mil (US104 million). The fisheries sector has provided direct employment opportunities to over 115 000 people and indirect benefits to 100 000 people in related occupations such as fish processing, boat building and other equipment manufacture and trade and public sector organizations. A socioeconomic survey conducted in 1996 noted a fisher population of 83 776 with 81.7% having fishing as their sole source of income, 12.5% as their main source and 4.3% as their second source. Fish is the main and preferred source of animal protein in Sri Lanka. Fish consumption accounts for 5% of the total food consumption and per capita fish consumption was 12.77 kg in 1998. However fish constitutes a substantial share of expenditure on food because of its high domestic price. The policy of almost all fisheries projects in Sri Lanka has been to maximize the fisheries resource utilization for direct extractive purposes rather than for sustainable resource management. This short-range orientation has increased the efficiency of fishing operations through the application of advanced technologies in fish capture, leading to a shift from the traditional fishing methods to the adoption of modern fishing gear. This has led to the depletion of fishery resources, particularly in the coastal waters. Thus there is a need to adopt programmes that emphasize the development of offshore fishing and thereby reduce fishing pressure in the coastal areas. Implementation of alternative livelihood opportunities would also improve the quality of life of coastal fishers.Fishery resources, Fishery surveys, Catch/effort, Trawling, Population characteristics, Biomass, Coastal fisheries, Mathematical models, Marine fisheries, Ecosystems, Socioeconomic aspects, Artisanal fishing, Economic benefits, Fishery industry, Capture fishery economics, Fish consumption, ISW, Sri Lanka,
Faces of Angels: Photography as a Fundraising Tool for AIDS-Affected Children in the Kibera Slums
The AIDS epidemic that has plagued sub-Saharan Africa for the last few decades has produced a growing population of children that have been detrimentally affected by the consequences of the disease—death of parents, declining household income, poor education, hunger, and stigma. These effects are heightened in urban slums like Kibera, where poverty, disease, and other problems run rampant. Experts concur that the best way to address the needs of AIDS-affected children is through community-based organizations on-site that work to reduce the risks faced specifically by these kids. Angels of Hope Kibera is one such institution, providing early childhood education, a feeding program, and counseling to children and families within the community, free of charge. However, many of these institutions, Angels of Kibera included, are running on very tight budgets that need to be expanded to adequately address the needs of the AIDS-affected youth they serve. Photography can serve as an avenue to help increase these budgets. This project seeks to use photographs taken of the children and interviews with their families to create a photobook that could potentially serve as a fundraising tool that can bring much needed revenue to Angels of Hope Kibera. The project will likely continue for some time, but many remain hopeful that it can do some good and succeed
Multiyear drought simulation with periodic-stochastic hydrologic processes
Previous studies on multiyear droughts are often limited to the analysis of historic annual flow series. A major problem in these studies is the unavailability of long historic flow records, on which to perform the analysis. To overcome this difficulty, the present study has used synthetically generated mean annual flow series to suppliment the historic flows. For the purpose of generating flows, a general methodology was developed to propose a mathematical model based on the harmonic and stochastic analyses of the historic flow series. The main objective was to derive a large population of multiyear drought events from the generated flow series, and to utilize this population for the simualtion of statistical & stochastic behaviour of the drought parameters.
The methodology was applied to a study area which includes six watersheds in the northern part of New Jersey and one watershed in the central New Jersey area. Analyses reveal that the mean annual flow series recorded at each selected streamflow gaging station, represents a periodic-stochastic process. The best model was determined for each stream, and used to generate a long annual flow series. Multiyear point droughts were identified by analyzing both the historic and generated flow series at a fixed truncation level. Four important drought parameters, namely, the duration, severity, magnitude and the time of occurrence were determined for each stream. The statistical properties of each of these parameters were then evaluated. It was found that the generated drought events closely follow the same statistical behaviour as the historic drought events. Based on the statistical properties, classical probability distributions such as gamma and log normal were fitted to the generated drought parameters. The applicability of these distribution functions to predict the extreme drought events have been illustrated with examples. In addition, the cross-correlation structure of the time of occurrence parameter of droughts has been identified with regard to spatial distribution of the point droughts over the study area
Usability evaluation of University of Colombo library website: A case study
The usability of the website of the main library, University of Colombo was measured for its effectiveness, efficiency and satisfaction through usability testing technique and post-test questionnaire. The study found that overall effectiveness of the library website was 88.69% while efficiency was 1.35 minutes/task. Overall, the users were very satisfied (3.94) with the library website
Effects of methoprene on extreme temperature tolerance and reproduction of Tribolium castaneum (Coleoptera: Tenebrionidae)
The juvenile hormone analogue methoprene is a reduced-risk insecticide. It disrupts insect development of immature stages preventing the emergence of adults. Several studies have shown that lower concentrations that permit the emergence of adults also have sub-lethal effects. Exposure to methoprene (Diacon II) at 3.33 ppm reduced the heat tolerance of Tribolium castaneum (Herbst) adults. However, it did not affect the heat tolerance of larvae at 0.07 ppm. Higher concentrations of methoprene were lethal to larvae without heat treatment. Methoprene (67 ppm) had no effect on the cold tolerance of adults. Furthermore, methoprene (0.03 ppm) did not alter cold tolerance of larvae. Exposure to 15°C for 2 weeks increased the cold tolerance of adults from 4 d to 7 d, and larvae 3 d to 5 d; however, methoprene concentrations had no effect on cold tolerance. Tribolium castaneum larvae exposed to methoprene (0.001 ppm) had lower fecundity as adults. Males were more affected than females in reducing the offspring when paired with untreated mates. These results show the potential of methoprene as an emerging insecticide and a viable alternative to currently used synthetic insecticides. The data on the effect of methoprene on extreme temperature tolerance of T. castaneum have been submitted to the Journal of Stored Products Research.Keywords: Methoprene, Extreme temperature tolerance, Reproduction, Larvae, Adult
Spectroscopic evidence for temperature-dependent convergence of light and heavy hole valence bands of PbQ (Q=Te, Se, S)
We have conducted temperature dependent Angle Resolved Photoemission
Spectroscopy (ARPES) study of the electronic structures of PbTe, PbSe and PbS.
Our ARPES data provide direct evidence for the \emph{light} hole upper valence
bands (UVBs) and hitherto undetected \emph{heavy} hole lower valence bands
(LVBs) in these materials. An unusual temperature dependent relative movement
between these bands leads to a monotonic decrease in the energy separation
between their maxima with increasing temperature, which is referred as band
convergence and has long been believed to be the driving factor behind
extraordinary thermoelectric performances of these compounds at elevated
temperatures.Comment: 6 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1404.180
Orbital selectivity causing anisotropy and particle-hole asymmetry in the charge density wave gap of -TaS
We report an in-depth Angle Resolved Photoemission Spectroscopy (ARPES) study
on -TaS, a canonical incommensurate Charge Density Wave (CDW) system.
This study demonstrates that just as in related incommensurate CDW systems,
-TaSe and -NbSe, the energy gap () of
-TaS is localized along the K-centered Fermi surface barrels and is
particle-hole asymmetric. The persistence of even at
temperatures higher than the CDW transition temperature
in -TaS, reflects the similar pseudogap (PG) behavior observed
previously in -TaSe and -NbSe. However, in sharp contrast to
-NbSe, where is non-zero only in the vicinity
of a few "hot spots" on the inner K-centered Fermi surface barrels,
in -TaS is non-zero along the entirety of both
K-centered Fermi surface barrels. Based on a tight-binding model, we attribute
this dichotomy in the momentum dependence and the Fermi surface specificity of
between otherwise similar CDW compounds to the
different orbital orientations of their electronic states that are involved in
CDW pairing. Our results suggest that the orbital selectivity plays a critical
role in the description of incommensurate CDW materials.Comment: 6 pages, 4 figure
The orientation of Tribolium castaneum adults in the presence of aggregation pheromone 4,8-Dimethyldecanal and food oils
Monitoring of Tribolium castaneum, the red flour beetle, involves the use of aggregation pheromone 4,8- dimethyldecanal (4,8 DMD) and kairomones such as cereal oils. Despite their present use, certain information which maximizes the efficacy of these compounds is still lacking. These experiments tested the effects of distance from the pheromone and edible oils on the orientation of T. castaneum adults. The movement of adults toward the aggregation pheromone was determined by changing the distance from the pheromone or the air flow. The adults released inside a glass apparatus tested their orientation either toward the food oils or the empty vial. The maximum trap catch was recorded at distances up to 60 cm from the pheromone and with the presence of air flow. The oils having botanical origin successfully attracted adults than those of animal origin. It is concluded that the orientation of T. castaneum adults varies with the distance from pheromone, air flow and the nature of food oil.Monitoring of Tribolium castaneum, the red flour beetle, involves the use of aggregation pheromone 4,8- dimethyldecanal (4,8 DMD) and kairomones such as cereal oils. Despite their present use, certain information which maximizes the efficacy of these compounds is still lacking. These experiments tested the effects of distance from the pheromone and edible oils on the orientation of T. castaneum adults. The movement of adults toward the aggregation pheromone was determined by changing the distance from the pheromone or the air flow. The adults released inside a glass apparatus tested their orientation either toward the food oils or the empty vial. The maximum trap catch was recorded at distances up to 60 cm from the pheromone and with the presence of air flow. The oils having botanical origin successfully attracted adults than those of animal origin. It is concluded that the orientation of T. castaneum adults varies with the distance from pheromone, air flow and the nature of food oil
ASSESSMENT OF PARTICIPATORY AGRO FORESTRY INTERVENTIONS IN INTEGRATED WATERSHED MANAGEMENT
A field study was carried out from march 1997 to December 1997 using direct. fieldmeasurements and a questionnaire survey to assess Forest Department's and sharedControl of Natural Resources (SCaR) Project's agrolorcstry inputs and 10 examine socialand institutional aspects concerned in planning and implementing agrotorestry inputs., Data were collected for two agrolorcstry samples and one control where only SCaR madesome interventionsBenefit - cost streams of farmers for each of different items, for unit of land agroforcstryplot and NPV of that unit arc evaluated hy considering timber value of teak and incomeearned by inter - cropping. Survival rate of teak plantation established both in 1995 and1996 years was between 97(!o - 9X%.Individual interviews were carried out to consider social and institutional aspects such asfarmer - farmer interactions, farmer officer interactions. problems arisen in co-ordinationof relevant line agencies. conflicts and conflict resolution between officers and differentinstitutions. altitudinal change of fanners etc.Other Institutions involved are: Department of Agriculture, Divisional Secretary Office.Government Cooperative shops, Department of Animal Husbandry and Veterinary Scienceand Coconut Cultivation Board.Major reasons for arising of conflicts arc: knowledge and attitudes of Officers of variousinstitutions arc different and objectives of various institutions arc different.Many conflicts had been arisen in relation to distribution of incentives: provided by theParticipatory Forestry Project. (PFP)Project's benefits included: Reduction of illicit felling. increased knowledge of farmers onconservation farming and environment conservation. significant increase in NPV andacceptable B: C ratio. increased market links for agroforestry produce etc.
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