1,161 research outputs found
Modelling the impact of climate change on health
The main objective of this thesis is to develop a robust statistical model
by accounting the non-linear relationships between hospital admissions due to
lower respiratory (LR) disease and factors of climate and pollution, and their
delayed effects on hospital admissions. This study also evaluates whether the
model fits can be improved by considering the non-linearity of the data, delayed
effect of the significant factors, and thus calculate threshold levels of the
significant climate and pollution factors for emergency LR hospital admissions.
For the first time three unique administrative datasets were merged: Hospital
Episode Statistics, Met office observational data for climate factors, and data from
London Air Quality Network.
The results of the final GLM, showed that daily temperature, rain, wind
speed, sun hours, relative humidity, and PM10 significantly affected the LR
emergency hospital admissions. Then, we developed a Distributed lag non-linear
model (DLNM) model considering the significant climate and pollution factors.
Time and ‘day of the week’ was incorporated as linear terms in the final model.
Higher temperatures around ≥270C a quicker effect of 0-2 days lag but
lower temperatures (≤00C) had delayed effects of 5-25 days lag. Humidity
showed a strong immediate effect (0-3 days) of the low relative humidity at
around ≤40% and a moderate effect for higher humidity (≥80%) with lag period
of 0-2 days. Higher PM10 around ≥70-μg/m3 has both shorter (0-3 days) and
longer lag effects (15-20 days) but the latter one is stronger comparatively. A strong effect of wind speed around ≥25 knots showed longer lag period of 8-15
days. There is a moderate effect for a shorter lag period of 0-3 days for lower
wind speed (approximately 2 knots). We also notice a stronger effect of sun hours
around ≥14 hours having a longer lag period of 15-20 days and moderate effect
between 1-2 hours of 5-12 days lag. Similarly, higher amount of rain (≥30mm)
has stronger effects, especially for the shorter lag of 0-2 days and longer lag of 7-
10 days.
So far, very little research has been carried out on DLNM model in such
research area and setting. This PhD research will contribute to the quantitative
assessment of delayed and non-linear lag effects of climate and pollutants for the
Greater London region. The methodology could easily be replicated on other
disease categories and regions and not limited to LR admissions. The findings
may provide useful information for the development and implementation of public
health policies to reduce and prevent the impact of climate change on health
problems
Survival of antibiotic resistant Pseudomonas strains in different types of water
A study was conducted to investigate the survival of five Pseudomonas strains resistant to antibiotics in different types of water. The selected Pseudomonas strains were designated as strain P1 (CT-29), strain P2 (CT-25), strain P3 (CT-36), strain P4 (CT-20) and strain P5 (CT-27) which were only recovered from farmed fishes. Six types of water viz., distilled water, saline water, tap water, deionized water, pond water and river water were used. Among these experimental waters, river water was found to be the most suitable for long-term survival of these strains. Deionized water did not support survival of all these Pseudomonas strains. Pond water, tap water and distilled water were moderately suitable for strain P1 and strain P4. Saline water was also found to be highly suitable for long-term survival in case of the strain P3 and moderately suitable for normal survival of strain P2 and strain P5
Factors affecting the adoption of carp polyculture in Bangladesh
A study was conducted to determine the factors affecting adoption of pond polyculture in six villages of three districts namely Mymensingh, Bogra and Narshingdi in Bangladesh. In Mymensingh, 75% pond owners adopted carp polyculture technology whereas in Bogra and Narshingdi only 16% and 25% pond owners, respectively adopted this technology for fish production. The production of fish per unit area was found to be 5 to 10 times higher in Mymensingh compared to that of Bogra and Narshingdi. Fish farmers identified three main problems affecting the adoption of pond polyculture viz. lack of input used in aquaculture, low fish yield and lack of credit facilities for pond polyculture. The technological awareness of the farmers directly contributed towards use of inputs in culture ponds. The positive impact of technological dissemination found on input use, fish yield and uplifted socioeconomic condition
Feeding habits of the sesarmid crab Perisesarma bidens (De Haan) in the mangroves of the Ryukyu Islands, Japan
Feeding habits of the sesarmid crab Perisesarma bidens (De Haan) was investigated in the mangroves of the Ryukyu Islands, Japan. Stomach content analysis showed that their diet consists mainly of mangrove leaves fragments, with small amounts of animal, algae and sediment matters, indicating that P. bidens is primarily detritivorous. The consumption rate of P. bidens was investigated under laboratory conditions by offering three different types of Kandelia candel mangrove leaves. Crab survived by eating green, yellow or brown leaves, preferring brown to either green or yellow leaves. Consumption rate of brown leaves was significantly higher when crabs were provided with green, yellow and brown leaves together, than when provided separately. It is considered that the brown leaves have a soft tissue, which is easily torn by the crab chelae and have apparently low C/N ratio. The C/N ratio of faeces, which indicated lower value than that of burrow leaves or sediments, derived from the symbiosis of bacteria in the stomach. The C/N ratio showed that sediments had C/N ratios 2/3 times lower than leaves sequestered in the burrow, indicating that mangrove sediments could have higher nutritional value than mangrove leaves. Perisesarma bidens showed significant consumption rates of mangrove detritus, therefore, it may have the important role as the grazer of mangrove detritus in view of the nutrient cycle in the mangroves
Investigation on bacterial flora of farmed freshwater prawn (Macrobrachium rosenbergii de Man) in Bangladesh
Total bacterial load in the haemolymph of freshwater prawn Macrobrachium rosenbergii varied from 6.2x10⁴ to 1.9x10⁷ CFU/ml whereas in the hepatopancreas, bacterial load varied from 1.9x10³ to 2.9x10⁵ CFU/g. The total bacterial load in the pond water varied from 2.6x10² to 4.1x10⁵ CFU/ml. The isolated bacterial genera in the haemolymph and the hepatopancreas of prawn were Streptococcus, Acinetobacter, Micrococcus, Aeromonas, Vibrio, Flavobacterium, Staphylococcus and Pseudomonas, whereas the detected bacterial genera in pond water were Micrococcus, Streptococcus, Vibrio, Flavobacterium, Staphylococcus, Pseudomonas and Aeromonas. Among the detected genera, Vibrio and Staphylococcus were found to be dominant genera in the haemolymph of the sampled prawn throughout the study period whereas Staphylococcus and Pseudomonas were dominant in pond water
Marketing System and Market Integration of Different Egg Markets in Bangladesh
The objectives of the study were to estimate costs and margins, seasonal price variation and to test market integration of egg. Primary and secondary data were used for this study. The higher marketing cost was incurred by aratdars and the lowest by retailer. On the other hand, retailers earned the highest net marketing margins. Analysis of market integration shows that egg market in Bangladesh was well integrated. The study identified some problems related to economic, technical, marketing, social and natural calamities aspects and suggested some measures for solving these problems. Key words: Engle Granger co-integration, Marketing cost & Margin, Market integration, Egg
Investigation on water quality in the Ashulia beel, Dhaka
The study was conducted to get an idea about the water quality of the Ashulia beel, and its temporal change over wet and dry seasons due to change of the physicochemical parameters. The water body has become a dumping ground of all kinds of solid, liquid and chemical wastes of bank side population and industries. Encroachment and illegal dredging has become a serious threat for the sound environment of the beel. The water parameters of pH 7.1-7.8 and alkalinity 30-63 mg/l in wet, and pH 7.1-8.4 and alkalinity 90-115 mg/l in dry season, respectively, which were within the standard range of DoE investigation. During wet season, EC 130-310 mg/l, TDS 80-132 mg/l, DO 1.1-2.1 mg/l and BOD -4.4-1.6 mg/l were measured. In dry season, EC 341-442 mg/l, TDS 207-276 mg/l, DO 0.5-2.0 mg/l and BOD 1.0-3.0 mg/l were measured. The comparative analysis showed that most of the water quality parameters of the Ashulia beel were suitable for aquatic organisms including fishes while the DO contents were much lower than the desirable level which may not be suitable for fishes
Integration of aquaculture into the farming systems of the floodprone ecosystems of Bangladesh: an evaluation of adoption and impact
This report presents the results of studies undertaken for incorporating low-external input aquaculture practices into the farming systems of a complex floodprone ecosystem in Bangladesh and the impacts of integration on income, nutrition and resource use in rural households. The study shows that multi-purpose ponds which were underutilized or unutilized because of risk of flooding could be made productive through proper management and incorporation into the existing farming systems. Farmers with minimal external inputs were able to increase fish production and consumption by 5 to 8 times.Integrated farming, Farming systems, Technology transfer, Fish culture, Impact assessment, Bangladesh,
Evaluation of yield performance and establishment methods of drought tolerant rice genotypes under rainfed condition in drought prone areas of Bangladesh
Two field experiments were carried out at farmer’s field of Rajshahi and Chapainawabgonj under the Department of Agronomy, BINA during aman season of 2017 and 2018 consecutively to evaluate the drought tolerant rice varieties under different establishment methods in rain fed condition. First experiment (E1) was conducted to find out the performance of varieties and second experiment (E2) was to find out the suitability of method of transplanting/sowing in combination with short duration aman varieties. Different methods were as direct seeding, puddled and un-puddled transplanting and cultivars were used to cultivate BRRI dhan56, Binadhan-7, Binadhan-17 (except in second experiment) and Huttra (local cultivar). The experiment was laid out in a randomized complete block design with three replications. The recommended fertilizer doses applied for the experiment were 80 kg N ha-1, 15 kg P ha-1, 50 kg K ha-1, 20 kg S ha-1 and 2 kg Zn ha-1. Nitrogen, phosphorus, potassium, sulphur and zinc were supplied from urea, TSP, MoP, gypsum and zinc sulphate monohydrate respectively while urea was applied in three equal splits. Among the cultivar Binadhan-17 produced statistically higher grain yield (5.62 t ha-1) at Chapainawabgonj. Among methods Binadhan-7 statistically higher grain yield 5.32 t ha-1 and 5.21 t ha-1, respectively) in puddle transplanting method both Chapainawabgonj and Rajshahi region during 2017. Among the cultivar Huttra (local) produced statistically higher grain yield (5.43 t ha-1) at Chapainawabgonj. Among methods, BRRI dhan56 statistically higher grain yield 6.37 t ha-1 and 6.19 t ha-1, respectively) in puddle transplanting method bothat Rajshahi and Chapainawabgonj during 2018. Overall results indicates that BRRI dhan56, Binadhan-7, Binadhan-17 performed better in puddled transplanting, Huttra (local) in direct seeding method in drought prone region of Bangladesh
A General Relativistic Rotating Evolutionary Universe - Part II
As a sequel to (Berman, 2008a), we show that the rotation of the Universe can
be dealt by generalised Gaussian metrics, defined in this paper.
Robertson-Walker's metric has been employed with proper-time, in its standard
applications; the generalised Gaussian metric imply in the use of a
non-constant temporal metric coefficient modifying Robertson-Walker's standard
form. Experimental predictions are madeComment: 7 pages including front cover. Publishe
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