Models for managing the deep aquifer in Bangladesh

In southern Bangladesh excessive levels of As in shallow groundwater have led to deeper groundwater becoming the main alternative source of As-free potable water. Hydrogeological configuration indicates that tube-wells pumping from these depths may be vulnerable to As breakthrough from shallow levels. The thesis explores a range of methods of representing lithological heterogeneity of the Bengal Aquifer System (BAS) in models of groundwater flow and travel time. The aim is to support models of arsenic (As) flux to the deep groundwater flow-system of BAS, and hence to aid assessment of the vulnerability of deep groundwater to invasion by As. The research uses an array of geological information including geophysical logs (n=12), hydrocarbon exploration data (n=11), and drillers' logs (n=589) from a 5000 km2 area to characterise the aquifer heterogeneity as a basis for alternative representations of hydrogeological structure in groundwater flow modelling. Groundwater samples from southern Bangladesh were analysed for 14C in order to determine groundwater age (n=23) and for hydrochemical (n=75) and isotopic (n=50) characterisation. A new hypothesis `SiHA (Silt-clay layers influence Hierarchical groundwater flow systems and Arsenic progression in aquifer)' is presented which integrates sedimentological heterogeneities, groundwater flow, and geochemical processes to explain the distribution and geological evolution of groundwater As in the aquifer. The hypothesis explains the spatio-vertical variability of groundwater As concentration by 'groundwater flow systems and differential flushing' in the aquifer. Groundwater flow models based on eight different yet plausible aquifer representations provide adequate simulations of hydraulic head, but contrasting implications for well catchments and travel times. The better representations are judged by comparing model outcomes of travel time with groundwater age determination using 14C. Comparisons demonstrate the importance of incorporating hydrostratigraphy and spatial heterogeneity in order to optimise model representations, and implications for the security of As-free deep groundwater in the BAS

Toxicity of malathion to silver barb (Barbodes gonionotus Bleeker) fingerlings

Static bioassays were performed to observe the toxic effect of malathion to Barbodes gonionotus at 0.0 to 20.0 ppm concentrations. Malathion at 5.0 ppm was harmless to B. gonionotus and concentrations above 6.0 ppm were found to be lethal. Malathion at 2.06 ppm was safe for the B. gonionotus

Effects of bio-slurry with chemical fertilizer on the performance of some high yielding varieties of boro rice (Oryza sativa L.)

Rice yield is greatly influenced by application of manures and fertilizer. Integrated use of organic manure and chemical fertilizer would be quite promising in providing better yield. To evaluate the effect of bio-slurry along with chemical fertilizer, a field experiment was conducted in the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh. The experiment was comprised of four varieties of boro (dry season irrigated) rice viz., (i) BRRI dhan28, (ii) BRRI dhan29 (iii) Binadhan-8 (iv) Binadhan-10 and four fertilizer management viz., (i) control, (ii) recommended dose of inorganic fertilizer, (iii) bio-slurry@ 5 t ha-1 + inorganic fertilizer, (iv) farmers’ practice (average 15 farmers). The experiment was laid out in a randomized complete block design with three replications. It is evident that variety and fertilizer management had significant effect on effective tillers hill-1, number of grains panicle-1 which ultimately influenced grain yield. The highest grain yield was (6.03 t ha-1) in Binadhan-8 followed by Binadhan-10 and BRRI dhan29. The lowest grain yield was found from BRRI dhan28. In respect of fertilizer management, grain yield was highest (5.90 t ha-1) in bio-slurry @ 5 t/ha + inorganic fertilizer. The lowest grain yield was found from control. The combined effect of variety and fertilizer application showed that highest grain yield (6.10 t ha-1) was found from Binadhan-8 with bio-slurry @ 5 t ha-1 + inorganic fertilizer and the lowest grain yield (4.68 t ha-1) was found from BRRI dhan28 with farmers’ practice. Thus, the variety Binadhan-8 with application of bio-slurry @ 5 t ha-1 + inorganic fertilizer was superior for obtaining highest yield

Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in Bangladesh During 2011

postprintA case control study was conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20/43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were done. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective. Key words: Avian influenza; case-control study; logistic regression; risk factors, observational studies

Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in Bangladesh During 2011

A case control study was conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20/43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were done. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective. Key words: Avian influenza; case-control study; logistic regression; risk factors, observational studies

Introduction of Routine Zinc Therapy for Children with Diarrhoea: Evaluation of Safety

On 8 May 2004, the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) recommended routine administration of zinc in the management of children, aged less than five years, with acute diarrhoea. In making the recommendation, WHO and UNICEF also suggested careful monitoring for adverse events associated with routine administration of zinc, particularly unusual or excess vomiting. The study assessed, in a phase IV trial, i.e. post-marketing surveillance of zinc, the occurrence of adverse events during the first hour after the administration of the first dose of zinc in children with acute or persistent diarrhoea. The study was conducted at the Dhaka Hospital of ICDDR,B and at an outpatient clinic operated by a local health NGO—Progoti Samaj Kallyan Protisthan (PSKP), Dhaka, Bangladesh. Eligible children, aged 3-59 months, were treated with 20 mg of zinc sulphate provided in a dispersible tablet formulation. The children were observed for 60 minutes following the initial treatment with zinc for adverse events, with particular attention given to vomiting or regurgitation. During the one-year observation period, 42,440 children (male 57% and female 43%) received zinc, and 20,246 (47.8%) of them were observed. Regurgitation and/or vomiting occurred in 4,392 (21.8%) of the children; 90.8% of these children had vomiting only once, 8.7% twice, and 0.5% more than twice. No children revisited the hospital for recurrent vomiting following their discharge. A significant proportion of infants and children may experience vomiting or regurgitation, usually once, following the administration of the first dose of zinc. This is a transient phenomenon that did not impact on continuation of treatment with zinc

Nutrient release from Vermicompost under anaerobic conditions in two contrasting soils of Bangladesh and its effect on wetland rice crop

Although its mechanism of action, particularly under wetland condition, is not clearly understood, vermicompost, a good source of humus and plant nutrients, has been used as organic manure in many parts of the world in order to increase crop production. Here, an anaerobic incubation study and a field study were conducted to observe the nutrient release pattern from vermicompost and its influence on performance and nutrient uptake in wetland rice. Two contrasting soils, viz. highly weathered terrace soil and very young floodplain soil, were subjected to anaerobic incubation, while the field trial was conducted in the terrace soil with control (no amendments), mineral fertilizer, vermicompost (10 t ha−1) + mineral fertilizer, cow dung (10 t ha−1) + mineral fertilizer, vermicompost (20 t ha−1) + mineral fertilizer and vermicompost (local farmer’s practice) + mineral fertilizer treatments. Results showed that there were significant increases in nitrogen (N) and phosphorous (P) release in floodplain soil but not in terrace soil, suggesting that nutrient release from vermicompost is soil-dependent. The performance of Boro rice in terms of yield and yield attributes improved significantly in the case of the integrated application of vermicompost with mineral fertilizer. Specifically, combined application of mineral nutrients and vermicompost (10 t ha−1) significantly increased grain yield by 25% compared to the control treatment. We believe that this occurred due to an improvement in supply and subsequent uptake of nutrients, especially N and P. Altogether, our results suggest that vermicompost could increase crop performance under field conditions, and, although these effects may not be significant in short-term incubation studies, they may be even larger in floodplain soil

Commercialization approach for Versatile Multi-Crop Planter: Lessons learnt

A Versatile Multi-crop Planter (VMP) was designed and built for seed and fertilizer application in lines when driven by 2-wheel tractors (2WT) for: single-pass shallow-tillage (SPST); strip planting (SP); zero tillage (ZT); bed planting (BP) and conventional tillage (CT). Land preparation cost by VMP was decreased by up to 75 % for single pass compared to CT (Haque at el., 2011). The VMP was capable of sowing many types of crop seeds from small jute seed up to maize seed. Demand for mechanized planters by smallholder farmers is growing rapidly due to the shortage of farm labour for operations such as planting or transplanting. Despite the promising seeder and planter developments, few of the present planters for 2WT are commercialized in Bangladesh. With the funding support from the Australian Centre for International Agricultural Research (ACIAR), the VMP commercialization activities commenced in 2012. Initially (2012 to 2014), the VMP commercialization activities were led by International Development Enterprises (IDE) and that approach was followed by a different approach implemented by the Project Implementation Office (PIO) of Murdoch University, Australia. In this paper, we will synthesis the VMP commercialization approaches and outcomes to identify key lessons learnt

A manufacturer-buyers integrated inventory model with generic distribution of lead times to deliver equal and/or unequal batch sizes

Although lead time variation is common in practice, integrated single-manufacturer multi-buyer model considering this factor is unavailable in the extant literature. This article considers generic distribution of lead times of delivering equal and/or unequal batch (sub-lot) sizes of a lot in developing a synchronised integrated single-manufacturer multi-buyer model. The batch sizes are assumed to be in geometric series. The variables considered in the model are the smallest batch size, total number of batches and number of unequal batch sizes delivered from the manufacturer to buyers. The smallest batch sizes delivered to the buyers are bounded below by 1 and above by the capacity of the transport vehicle. The minimal total cost solution technique to the model is derived by the method of differentiation. Significant minimal total cost reductions by the synchronised flow is illustrated through solutions to some numerical example problems. Sensitivity analyses on increasing costs of transportation, shortage, inventory and increasing mean lead times upon the optimal solution have been performed

Biochemical analysis on blood and crop contents of household chickens along with their production and health status in Bangladesh

This study aimed to assess the biochemical parameters of household chickens at crop and blood levels and measure the body weight. For this purpose, 350 Deshi (local) and 27 Fayoumi day old chicks were reared in 2 separate brooders within a house for 15 days. Body weight, serum total protein and calcium levels of these chicks were evaluated on day 0 and 15. After control house trial, birds were distributed among the selected households. Again, body weights and certain biochemical parameters were assessed from randomly selected birds at 60, 120 and 180 days of age. Fayoumi birds gained higher weight (P<0.001) than at control trial, whereas Deshi birds attained better weight (P<0.001) at household. Crop contents were dominated by carbohydrate. The level of crude proteins and calcium in crop contents increased along with age regardless of bird types. The average phosphorous in the crop contents was 0.3% (60 days), 2.6% (120) and 0.7% (180) regardless of bird types. Both serum total protein (P<0.05) and calcium (P<0.05) were significantly difference in between bird types at control house study. In conclusion, Deshi birds attained higher weight at household. The crude protein was below standard. Calcium and Phosphorous levels in the crop contents varied with ages, regardless of bird types. \ua9 2012 PVJ