Self-recruiting species (SRS) in aquaculture : their role in rural livelihoods in two areas of Bangladesh

Self-recruiting species (SRS) are the aquatic animals that do not require repeated stocking in farmer managed aquatic systems (FMAS) and can be of indigenous or exotic origin (Little, 2002). Current concept of conventional aquaculture greatly underestimated the contribution of SRS to the livelihoods and particularly nutritional security of the poor. The present study examines the role of SRS in poverty focused aquaculture. The role of SRS in aquaculture was evaluated from the perspective of people dependent on them in terms of well-being, gender, resource access and broader livelihoods in the northwest and south-central region of Bangladesh. SRS management practices, already an existing component of aquaculture in FMAS, were explored to define sustainable management strategies that benefited poor. The thesis uses a livelihoods framework within a methodological context of participatory action research at household, community and national level. The process begins with a Participatory Community Appraisal (PCA) in 18 communities with 360 participants which then directs further investigation at household level through survey, longitudinal study farmer and farmer participatory action research over a systematic 4 year investigation from 2001 to 2004. At the PCA stage, the context of livelihoods, importance of popular aquatic animals and their different sources were examined. The more frequently mentioned and higher scored SRS by the communities were Clarias batrachus, Anabas testudineus, Macrobrachium sp., Puntius sp., Heteropneustes fossilis, Channa punctatus, Mystus vittatus, Amblypharyngodon mola, Channa striata, Macrognathus puncalus. The sources of these aquatic animals provided a better understanding of the diverse typology of farmer managed aquatic systems (FMAS) and showed the importance of both FMAS and open systems to sustain a self-supporting population of aquatic animals for nutritional security of the poor. Rice and other crop farming, fish culture, livestock and poultry rearing, service and business were found to be common occupations among better off households where as share-cropping, petty trade, fishing, selling agricultural and non-agricultural labour were of greater importance to poorer households. Both gender and well-being affected livelihoods with significant differences in involvement of the better off and poorer. PCA findings were later validated at a national level stakeholder workshop with 138 government, non-government officials, researchers and academics which established a broader understanding of the prospects and constraints of SRS culture and conservation. The baseline survey with 119 households further examined the characteristics and access of key farmers to managed aquatic systems, livelihood assets, vulnerability and the behaviours of households managing SRS. Access to FMAS and SRS are of much greater importance to poorer than to the rich. Positive, negative and neutral attitudes towards managing SRS were not significantly affected by well-being. Access to appropriate types of FMAS, SRS management knowledge, traditional taste, greater involvement in non-farm activities, family need were all associated with the SRS positive attitude. Results from the year round longitudinal study with 50 households focused on the seasonal dynamics of food consumption and its connection to livelihoods in terms of sources, income and expenditure. Aquatic animals are the 3rd most important contributor to the rural Bangladeshi diet after cereal and vegetables by weight and the 2nd most important contributor by price after cereal. FMASs are important source of aquatic animals compared to other sources such as open system, market and given sources (free from neighbours and relatives). SRS were accounts for 52% of the total aquatic animal consumption. Even among some very low income vulnerable groups such as day labourers and rickshaw pullers, SRS was found important in their diet. Poorer households rely significantly more on SRS than richer households. The total amount of SRS consumed by thenhosueholds over the year was strongly correlated with total number of SRS species consumed per year and further emphasised the significance of maintaining biodiversity. The pre monsoon dry period as April and May were low consumption periods in both zones. Rainy and post rainy season July to October were the peak consumption months in the northwest zone and June to November in south-central zone. The year round farmer participatory trial with 29 farmers confirmed the value of SRS within culture systems with lack of any major conflicts in the husbandry of non-stocked species with popular carps in the system which, in the past regarded as weed fish and have been generally excluded from formal aquaculture. The study found a range of species of both commercial and non-commercial SRS have greater significance to the poor than to the richer households particularly in terms of household consumption, income and social value. More deliberate attention towards avoidance of negative actions towards SRS in aquaculture in the lean season may also expand niche benefits for non-pond owners and vulnerable social groups such as fishers. Current investigations also revealed the complementarities of stocked fish particularly during dry months when SRS are less available. In spite of the poor having limited access to ponds, the seasonal scarcity of water in dry seasons and habitat degradation, SRS remains an important and valuable food item for the poor in low income vegetable scarce months. The study recommends future emphasis on the management and conservation of both commercial and non-commercial (mainly for consumption) SRS in FMAS particularly during the lean season and also to maintain the integrity of the permeable nature of FMAS and its linkage with the broader open systems for the sustained availability of such self-recruiting population. Finally the study greatly influenced the perception of utilising both stocked and non-stocked species in formal aquaculture. It is necessary to take urgent steps to avoid negative actions to damage SRS and formulate an integrated approach to water, agriculture, environment and fisheries management to sustain them for current and future nutritional and livelihoods security of the poor.EThOS - Electronic Theses Online ServiceDFID-AFGRPGBUnited Kingdo

Review of natural fibre-reinforced hybrid composites

Natural fibre-reinforced hybrid composites which contain one or more types of natural reinforcement are gaining increasing research interest. This paper presents a review of natural fibre-reinforced hybrid composites. Both thermoplastic and thermoset composites reinforced by hybrid/synthetic fibres or hybrid/hybrid fibres are reviewed. The properties of natural fibres, the properties and processing of composites are summarised

The Influence of the Type of Lime on the Hygric Behaviour and Bio-Receptivity of Hemp Lime Composites Used for Rendering Applications in Sustainable New Construction and Repair Works

The benefits of using sustainable building materials are linked not only to the adoption of manufacturing processes that entail reduced pollution, CO2 emissions and energy consumption, but also to the onset of improved performance in the building. In particular, hemp-lime composite shows low shrinkage and high thermal and acoustic insulating properties. However, this material also shows a great ability to absorb water, an aspect that can turn out to be negative for the long-term durability of the building. For this reason, the hygric properties of hemp-based composites need to be studied to ensure the correct use of this material in construction and repair works. The water absorption, drying and transpirability of hemp composites made with aerial (in the form of dry powder and putty) and hydraulic limes were investigated here and related to the microbial growth induced by the water movements within the material. Results show that hemp-natural hydraulic lime mixes exhibit the highest transpirability and drying rate, the lowest water absorption by immersion and capillary uptake and the least intense microbial attack and chromatic change. A microscopical study of the hemp shives also related their great ability to absorb water to the near-irreversible swelling of their structure under dry-wet conditions.The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 326983 (NaturALiMe), and the Spanish project MAT-2012-34473 of the Ministerio de Ciencia y Competitividad. Author MB, owner of the CANNABRIC company, had some role in the design and preparation of mortar samples and in the preparation of this manuscript, but did not have any additional role in data collection and analysis

Hypercalcemia after transplant nephrectomy in a hemodialysis patient: a case report

<p>Abstract</p> <p>Introduction</p> <p>Hypercalcemia is a complication often seen in chronic hemodialysis patients. A rare cause of this condition is sarcoidosis. Its highly variable clinical presentation is challenging. Especially in patients suffering chronic kidney graft failure the nonspecific constitutional symptoms of sarcoidosis like fever, weight loss, arthralgia and fatigue may be easily misleading.</p> <p>Case presentation</p> <p>A 51 year old male developed hypercalcemia, arthralgia and B-symptoms after explantation of his kidney graft because of suspected acute rejection. The removed kidney showed vasculopathy and tubulointerstitial nephritis, which had not been overt in the biopsy taken half a year earlier. Despite explantation and withdrawal of the immunosuppression the patient's general condition deteriorated progressively. A rapid rise in serum calcium finally provoked us to check for sarcoidosis. CT scans of the lungs, broncho-alveolar-lavage and further lab tests confirmed the diagnosis.</p> <p>Conclusion</p> <p>This case demonstrates that withdrawal of immunosuppressive drugs sometimes unmasks sarcoidosis. It should be considered as differential diagnosis even in hemodialysis patients, in whom other reasons for hypercalcemia are much more common.</p

Transcriptional Responses of Resistant and Susceptible Fish Clones to the Bacterial Pathogen Flavobacterium psychrophilum

Flavobacterium psychrophilum is a bacterial species that represents one of the most important pathogens for aquaculture worldwide, especially for salmonids. To gain insights into the genetic basis of the natural resistance to F. psychrophilum, we selected homozygous clones of rainbow trout with contrasted susceptibility to the infection. We compared the transcriptional response to the bacteria in the pronephros of a susceptible and a resistant line by micro-array analysis five days after infection. While the basal transcriptome of healthy fish was significantly different in the resistant and susceptible lines, the transcriptome modifications induced by the bacteria involved essentially the same genes and pathways. The response to F. psychrophilum involved antimicrobial peptides, complement, and a number of enzymes and chemokines. The matrix metalloproteases mmp9 and mmp13 were among the most highly induced genes in both genetic backgrounds. Key genes of both pro- and anti-inflammatory response such as IL1 and IL10, were up-regulated with a greater magnitude in susceptible animals where the bacterial load was also much higher. While higher resistance to F. psychrophilum does not seem to be based on extensive differences in the orientation of the immune response, several genes including complement C3 showed stronger induction in the resistant fish. They may be important for the variation of susceptibility to the infection