Locations Of Bangladesh Research Articles

Impacts of urea deep placement on nitrous oxide and nitric oxide emissions from rice fields in Bangladesh

Urea deep placement (UDP) increases nitrogen use efficiency (NUE) in lowland rice fields by reducing ammonia volatilization, surface runoff and increasing nitrogen uptake. However, its effects on N losses as nitrous oxide (N2O) and nitric oxide (NO) are not yet clear. We conducted field experiments at two locations of Bangladesh — Bangladesh Agricultural University (BAU) and Bangladesh Rice Research Institute (BRRI) — to determine the effects of UDP vs broadcast urea on N2O and NO emissions from rice fields.N2O and NO emissions were measured from three N fertilizer treatments (control [0kgN/ha], UDP, broadcast urea) using automated gas sampling and analysis system continuously for three rice growing seasons — Aus (May–Aug), Aman (Aug–Dec) and Boro (Jan–May). Urea was applied as 2–3 split application, while for UDP treatment, urea briquettes were deep placed (7–10cm depth) between 4 hills of rice at alternate rows to meet recommended N rates in a single application. Treatments were arranged in a randomized complete block design with three replications and N2O and NO measurements were done at every three-hour interval.N2O emissions were sporadic and event specific. Peaks in N2O emissions were observed after broadcast application of urea, during dry period and after re-flooding of the dry soil. For the rest of the time during the rice-growing season, emissions were very low to negligible. However, across the rice-growing seasons, UDP significantly (P<0.05) reduced N2O emissions compared with broadcast urea. Moreover, N2O emissions showed significant spatial and seasonal variations. They were higher during Boro season compared with Aus and Aman seasons and at BAU site than that of BRRI. Conversely, emissions between Aus and Aman seasons and between control and UDP treatments were similar. In contrast to N2O emissions, NO emissions were negligible and not affected by fertilizer treatment. However, significant spatial and seasonal variations were observed, with higher NO emissions at BRRI site compared with BAU and during Boro than that of Aus season.

Isolation and screening of multifunctional rhizobacteria from the selected sites of Madhupur, Narshingdi and Mymensingh, Bangladesh

A laboratory experiment was performed to isolate some native rhizobacteria that could be used as bioinoculants for sustainable crop production. A total of 43 rhizobacteria were isolated from undisturbed plant rhizosphere soils of three different locations of Bangladesh and evaluated their plant growth promoting traits, both direct and indirect. The study has screened out isolates on the basis of their phosphorous solubilization and nitrogen (N) fixation. The phosphate solubilization assay in National Botanical Research Institute of Phosphate (NBRIP) medium revealed that 12 bacterial isolates were able to solubilize tricalcium phosphate and the rhizobacteria M25 showed best performance with a PSI of 3.33 at 5 day. Exactly 47% (20 isolates) of the isolated rhizobacteria were able to grow in N-free Winogradsky’s medium, which is an indication of potential N2-fixers. Among the 20 potential N-fixers, 15 were able to grow within 24 hours of incubation indicating that they are more efficient in Nfixation. The present study successfully isolated and characterized 43 rhizobacteria. Some of these isolated rhizobacteria have potential plant growth promoting traits and are potential plant growth promoting rhizobacteria (PGPR) candidate. Considering all plant growth promoting traits, the isolate F37 was the best followed by M6. However, further experiments are needed to determine the effectiveness of these isolates under in vitro and different field conditions to understand the nature of interaction with the plant and environment.Res. Agric., Livest. Fish.2(1): 1-8, April 2015

Microbiological quality analysis of raw, pasteurized, UHT milk samples collected from different locations in Bangladesh

Present study attempted to determine the microbiological quality of raw, pasteurized and UHT (Ultra High Temperature-processed) milk samples collected from different locations in Bangladesh. A total of 46 samples were studied including 22 raw milk samples from the local dairy markets and 24 different brands of pasteurized and ultrahigh temperature (UHT) treated milk manufactured in different beverage industries. The samples were examined for determining the total viable bacterial count (TVBC) and total coliform count (TCC). Results revealed that the raw milk samples were substandard in terms of TVBC and TCC. The range of TVBC and TCC in raw milk samples was 5.2×108 to 1.3×107 cfu/ml and 4.2×104 to 1.0×104 cfu/ml, respectively. On the contrary, the quality of pasteurized and UHT-treated milks was excellent. The TVBC range in pasteurized milk samples was from 1.8×103 to 1.1×102 cfu/ml, slightly lower than that recommended by the Bangladesh Standards and Testing Institution (BSTI). Interestingly sample numbers P-6, P-10 and P-12 of pasteurized milk samples had no growth at all both in terms of TVBC and TCC and none of the UHT processed milk contained any bacteria. So from the consumer point of view, both types of processed milk can be considered safe for consumption within the mentioned expiry date. DOI: http://dx.doi.org/10.3329/sjm.v4i1.22753 Stamford Journal of Microbiology, Vol.4(1) 2014: 5-8

Prevalence and determinants of caesarean section in private and public health facilities in underserved South Asian communities: cross-sectional analysis of data from Bangladesh, India and Nepal

ObjectivesTo describe the prevalence and determinants of births by caesarean section in private and public health facilities in underserved communities in South Asia.DesignCross-sectional study.Setting81 community-based geographical clusters in four locations...

Identification and confirmation of quantitative trait loci controlling resistance to mungbean yellow mosaic disease in mungbean [Vigna radiata (L.) Wilczek

Mungbean yellow mosaic India virus (MYMIV) is a major constraint on mungbean production in South and Southeast Asia. The virus belongs to the genus Begomovirus, causing yellow mosaic disease and subsequently yield loss up to 75–100 %. The present study employed F2 and BC1F1 populations derived from a cross between susceptible (BARImung 1; BM1) and resistant (BARImung 6; BM6) mungbeans to identify quantitative trait loci (QTLs) associated with resistance to MYMIV. Resistance to the virus was evaluated using F2:3 and BC1F1:2 populations under field conditions in two locations in Bangladesh in 2012. A total of 1,165 simple sequence repeat markers from different legumes were used to detect the polymorphism between BM1 and BM6. Sixty-one polymorphic markers were used to construct a linkage map comprising 11 linkage groups. Composite interval mapping consistently identified two major QTLs, qMYMIV2 on linkage group 2 and qMYMIV7 on linkage group 7, conferring the resistance in both F2 and BC1F1 populations. qMYMIV2 and qMYMIV7 accounted for 31.42–37.60 and 29.07–47.36 %, respectively, of the disease score variation, depending on populations and locations. At both loci, the resistant alleles were contributed by the parent BM6. qMYMIV2 appeared to be common to a major QTL for MYMIV resistance in mungbean reported previously, while qMYMIV7 is a new QTL for the resistance. The markers linked to the QTLs in this study are useful in marker-assisted breeding for development of mungbean varieties resistant to MYMIV.

Variability, character association and diversity analysis of ridge gourd (Luffa acutangula roxb.) genotypes of Bangladesh

Sixty genotypes of ridge gourd (Luffa acutangula Roxb.) were collected from different locations of Bangladesh and were used to study their variability, character association and genetic diversity. Seventeen traits studied, of these, eight showed high heritability (over 80%). Correlation coefficient study indicated that yield per plant had highly significant positive relationship with the number of fruits per plant (r = 0.874**), average fruit weight (r = 0.707**), vine length at harvest (r = 0.359**) and length of fruit (r = 0.334**). On the other hand, the sex ratio and circumference of fruit exhibited negative association with yield. Path co-efficient analysis showed that number of fruits per plant exhibited the highest positive direct effect (0.7192) on yield followed by average fruit weight (0.4656). Based on Mahalanobis’ D2 statistics, the sixty genotypes were grouped into four different clusters. Clustering pattern revealed that genotypes collected from the same location were grouped into different clusters. The average intercluster distances were always higher than the average intracluster distances suggesting wider genetic diversity among the genotypes within the cluster. Custer-III had the highest intracluster distance (97.9).DOI: http://dx.doi.org/10.3329/sja.v10i2.18319 SAARC J. Agri., 10(2): 1-10 (2012)

The Effect of Seed Sources Variation and Presowing Treatments on the Seed Germination ofAcacia catechuandElaeocarpus floribundusSpecies in Bangladesh

The seed germination of seed sources and presowing treatments ofAcacia catechuandElaeocarpus floribundusseeds were conducted in the nursery of Bangladesh Agricultural University. The seeds were collected from matured and healthy trees from four different locations in Bangladesh and treated with six presowing methods. The germination test was conducted in polybags with a mixture of topsoil and cow dung in a ratio of 3 : 1. The results of ANOVA showed no significant differences among seed sources but statistically significant differences among the presowing treatments for both species. Thus the presowing methods affected the germination process of seeds, and then the highest germination success was found to be 91.26% in hot water (80°C for 10 min), treatment inAcacia catechuand the highest germination success (89.81%) ofElaeocarpus floribunduswas found in H2SO4treatment followed by 86.35% and 78.42% in treatments with hot water (100°C for 12 min) and scarification. The study also revealed that the interactions between seed source variation and presowing methods effect significantly differed in seed germination percentages. Therefore, it is concluded that hot water treatment can be suggested on seed germination of both species for developing nurseries and rural Bangladesh.

Socio - Economic Characteristics of Farmers Influencing Adaptation to Climate Change: Empirical Results from Selected Homegardens in South Asia with Emphasis on Commercial Orientation

Climate change is considered one of the most challenging current global issues. Adaptability to changes is considered as one of the two major approaches to face the impact of climate change. This study examined the type of adaptation strategies used by the homegardeners in selected locations of South Asia and evaluated the extent to which the choices of such strategies are influenced by the socioeconomic characteristics of the homegardeners. Data for 368 homegardens in five locations in Bangladesh, India and Sri Lanka were collected through a household survey. Commonly used adaptation strategies by the farmers were examined to identify the level of adaptability of homegardeners to the probable impacts of climate change. A binomial probit model was estimated using pooled data to identify the factors determining the probability of adoption, considering the tree crop diversity of the garden, ownership of livestock, perceptions on climate change, level of education, number of years living in the village, experience in farming, location and commercial orientation as the explanatory variables. The results of the estimation revealed that commercial orientation, perceptions on climate changes, years of experience of the homegardeners, and location significantly influence the probability of adoption of a strategy. The results indicate that the policies and programs to improve adaptation to climate change should consider location specific and household specific characteristics. Sri Lanka Journal of Advanced Social Studies, Vol 2:No. 2, July – December 2012; Page 71-90 DOI: http://dx.doi.org/10.4038/sljass.v2i2.6208

Is aristolochic acid nephropathy a widespread problem in developing countries?: A case study of Aristolochia indica L. in Bangladesh using an ethnobotanical–phytochemical approach

Ethnopharmacological relevanceSpecies of Aristolochia are associated with aristolochic acid nephropathy (AAN), a renal interstitial fibrosis and upper urinary tract cancer (UUC). Aristolochic acid nephropathy has been reported in ten countries but its true incidence is unknown and most likely underestimated. By combining an ethnobotanical and phytochemical approach we provide evidence for the risk of AAN occurring in Bangladesh. More specifically, we assess the intra-specific variation of aristolochic acid analogues in medicinally used Aristolochia indica samples from Bangladesh. Materials and methodsEthnobotanical information was collected from 16 kavirajes (traditional healers) in different study locations in Bangladesh. Plant samples were obtained from native habitats, botanical gardens, herbal markets and pharmaceutical companies. The samples were extracted using 70% methanol and were analysed using LC-DAD-MS and 1H-NMR. ResultsRoots as well as leaves are commonly used for symptoms such as snake bites and sexual problems. Among the informants knowledge about toxicity or side effects is very limited and Aristolochia indica is often administered in very high doses. Replacement of Aristolochia indica with other medicinal plants such as Rauvolfia serpentina (L.) Benth. ex Kurz was common. Aristolochia indica samples contained a variety of aristolochic acid analogues such as aristolochic acid I, aristolochic acid II, cepharadione A and related compounds. ConclusionsAAN cases are likely to occur in Bangladesh and more awareness needs to be raised about the health risks associated with the use of Aristolochia indica and other species of Aristolochia as herbal medicines.

Effects of variation in seed sources and pre-sowing treatments on seed germination of Tamarindus indica: a multi-purpose tree species in Bangladesh

We investigated the morphology and germination of Tamarindus indica seeds in order to discover the effects of variation in seed sources and pre-sowing treatments on germination. The experiment was carried out in the nursery of the Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Seeds were collected from different but healthy trees from various locations in Bangladesh and subjected to four pre-sowing treatments, i.e., control, immersion in cold water (4°C for 24 h), immersion in hot water (80°C for 10 min) and scarification with sand paper. Seed germination was carried out in poly-bags with a mixture of topsoil and cow dung in the ratio of 3:1. The average length of the fresh seeds was 1.35 ± 0.26 cm, their width 1.07 ± 0.20 cm and thickness 0.69 ± 0.11 cm. The results revealed that pre-sowing treatments affected the germination process of seeds, which significantly increased the germination percentage with the cold water (81.67%) and scarification with sand paper (82.33%) treatments, compared with those in the control (58.33%) and hot water treatment (59.00%). In all treatments germination started on average within 5 to 7 days after the start of the treatments and were completed from 13 to 19 days later. The greatest success in germination (82.33%) was found in scarification with sand paper, followed with 81.67% in the cold water treatment. The results of analyses of variance (ANOVA) showed significant differences (p < 0.05) in germination closing dates, seed germination periods and germination percentages among the treatments but no significant difference among seed sources. However, the effect of the interaction between seed source variation and pre-treatment differed significantly in seed germination closing dates and germination percentages. We recommend cold water treatment (submersion of seed at a temperature of 4°C for a 24-h period) for seed germination of T. indica in rural Bangladesh.

Nutritional status of adolescents in Bangladesh: Comparison of severe thinness status of a low-income family′s adolescents between urban and rural Bangladesh

Introduction:This study estimated the nutritional as well as the severe thinness status (according to the World Health Organization [WHO]) of a low-income family's adolescent girl and also their early age of life in both urban and rural adolescent girls in Bangladesh.Materials and Methods:This cross-sectional study measured the height, weight and muac by standard procedure for calculating the body mass index according to the WHO reference. A 2-days, 24-h food recall and food frequency questionnaire was used to estimate the food frequency, energy intake, protein and carbohydrate. A multistage, multiphase stratified cluster sampling was used to select the study population from two locations in Bangladesh: Dhaka city and the east region of Trishal (district of Mymensingh). The study subjects were low-income families’ adolescent girls (n = 214) aged 14–17 years. The two groups contained an equal number of respondents (n=107/group).Results:Results revealed that economic status had a significant effect on nutritional status. Nutritional status of low-income families’ adolescent were low both in urban and rural adolescents, but severe thinness rate according to the WHO of urban (22.4%) adolescents was much higher than rural (10.3%) adolescents (chi-square = 4.9 and P-value = 0.01), and was also higher at an earlier age of their life. In food intake distribution and food consumption status, the same results were seen. The percentage of never eat meat and fish of low-income families adolescent girls were (29.7%, 11.4%) in urban group and (24.4%, 6.8%) in rural group. The main food rice consumption of urban adolescents was also about half that of rural adolescents per day. The study also shows that intake of energy, protein, carbohydrate and fat were significantly different between urban and rural girls. Only 53% energy was covered of the recommended daily energy intake in urban adolescents.Conclusion:Based on the food recall and anthropometric results, we conclude that malnutrition is common in low-income family's adolescents, and the severe thinness rate is much higher in urban than in rural adolescents, as also their early age of life in both low-income family's adolescents girls in Bangladesh.

Energy Demand &amp; Prospect of Geothermal Energy as the Solution of Energy Crisis of Bangladesh – an Approach to Green Energy Solution

Bangladesh has among the lowest per capita energy (240 kg oil equivalents) consumption in the world and is severely dependent on additional environmentally friendly renewable energy resources in the future. Among the possible energy resources that could be explored is the potential geothermal energy in regions of higher geothermal gradients with favorable geo-tectonic setting and ideal petro-physical properties. A preliminary examination of bottom hole temperatures of a large number of on-shore wells spread over a vast area in the eastern part of the country, especially in Thakurgaon-Mymensingh-Sunamgonj-Sylhet through in the Bengal fore deep, strongly suggests that several other areas are of great interest for further studies in order to determine their geothermal energy potential. Bangladesh has witnessed a high demand for uninterrupted electricity due to rapid civilization in the last few years. Bangladesh needs now a reliable green energy sources as its power sector beset by many infrastructural problems (inefficient transmission system, very old power stations and cumbersome decision making process). Bangladesh has taken initiative to generate 25000MW electricity within 2021. In this regard, geothermal energy can be a viable and useful alternative and this paper proposes the prospects of its introduction to the power sector of Bangladesh. In this paper, a study is presented that shows the suitable locations in Bangladesh where geothermal power plants can be set up easily. Recently, the Ministry of Power, Energy and Mineral Resources has approved the establishment of the first ever geothermal power plant (200MW) in the country. A total of approximately 1000 MW can be added into the energy grid of Bangladesh through geothermal power systems. The geothermal energy is green, indigenous, locally occurring and continuously available independent of climatic changes. It will help to reduce the huge oil bill that the country is facing now, provided the national planners give adequate attention and support for the development of geothermal energy at a rapid pace to reduce the severe electricity crisis in Bangladesh as other energy resources like peat, hydropower, nuclear, wind, tidal / waves are not significant at present.

Wind Power: A Renewable Alternative Source of Green Energy

Mean wind speed Wind power Green energy Weibull’s distribution Available power In the study, the statistical analysis of wind speed data has been carried out for different locations of Bangladesh over the period of ten years from 1998 to 2007. The hourly measured wind speed data above 30 m height has been collected from Bangladesh meteorological department and sorted in sequence of appropriate frequency like hourly, daily, monthly and annually. The data has been fitted for Weibull’s distribution and determined two important parameters like Weibull’s shape factor and Weibull’s scale factor by three methods and compared to each other. The theoretical available power in Watt/m2 has been determined for the prospective wind sites. It also determined the practically extractable Power by wind turbine in Watt/m2. Finally, it has been found that the available power in the wind can be used for lifting water for irrigation purpose in the dry season.

Characterizing the Picornavirus Landscape among Synanthropic Nonhuman Primates in Bangladesh, 2007 to 2008

The term synanthropic describes organisms that thrive in human-altered habitats. Where synanthropic nonhuman primates (NHP) share an ecological niche with humans, cross-species transmission of infectious agents can occur. In Bangladesh, synanthropic NHP are found in villages, densely populated cities, religious sites, and protected forest areas. NHP are also kept as performing monkeys and pets. To investigate possible transmission of enteric picornaviruses between humans and NHP, we collected fecal specimens from five NHP taxa at16 locations in Bangladesh during five field sessions, from January 2007 to June 2008. Specimens were screened using real-time PCR assays for the genera Enterovirus, Parechovirus, and Sapelovirus; PCR-positive samples were typed by VP1 sequencing. To compare picornavirus diversity between humans and NHP, the same assays were applied to 211 human stool specimens collected in Bangladesh in 2007 to 2008 for acute flaccid paralysis surveillance. Picornaviruses were detected in 78 of 677 (11.5%) NHP fecal samples. Twenty distinct human enterovirus (EV) serotypes, two bovine EV types, six human parechovirus serotypes, and one virus related to Ljungan virus were identified. Twenty-five additional enteroviruses and eight parechoviruses could not be typed. Comparison of the picornavirus serotypes detected in NHP specimens with those detected in human specimens revealed considerable overlap. Strikingly, no known simian enteroviruses were detected among these NHP populations. In conclusion, enteroviruses and parechoviruses may be transmitted between humans and synanthropic NHP in Bangladesh, but the directionality of transmission is unknown. These findings may have important implications for the health of both human and NHP populations.

INFLUENCE OF VEGETABLE INCLUSION IN RICE MONOCULTURE ON SOIL ORGANIC MATTER QUALITY UNDER SUB-TROPICAL CLIMATE

Soil organic matter (SOM) quality and iits decomposibility is influenced by cropping pattern. However, little is known on this matter, particularly so far rice monoculture or comination of vegetables with rice culture. Therefore, four pairs of fields having vegetable-rice and rice-rice cropping pattern were selected from four different locations in Bangladesh, covering floodplain and terrace soils. Soils were first physically fractionated into particulate organic matter (POM) and silt and clay sized OM. The silt and clay sized OM was further chemically fractionated by oxidation with 6% NaOCl to isolate an oxidation-resistant OM fraction, followed by extraction of mineral bound OM with 10% HF (HF-res OM). The results show that there is a small increase in POM in vegetable compared with rice soils. Among the chemical treatments, NaOCl oxidized the largest amount of OC and N from the silt and clay fractions of vegetable soils. The silt and clay N in vegetable soil was found to be more susceptible to NaOCl treatment compared with OC. Both the HF-extracted (HF-ex) and HF-res OM fractions were found to be lower in vegetable soils compared with rice soils. Results from both physical and chemical fraction of SOM suggest that SOM accumulated in vegetable-rice cropping pattern are more labile than the solely rice based cropping pattern and prone to decompose quickly in any change of land use.

Design and Validation of Wind Turbine’s Power Simulation by Remote Controlled Motor

Weibull’s shape factor Weibull’s scale factor Wind turbine design Microcontroller PWM signal The study presents the statistical analysis of wind data at different location of Bangladesh over a period of years. The data has been shorted in sequence of appropriate frequency as hourly, daily and monthly mean wind speed. Two important parameters like Weibull’s shape factor “k” and Weibul’sl scale factor “c” have been obtained from the data. Weibull’s function F(v), Weibull’s probability density function f(v), and available power in the wind (w/m 2 ) have also been obtained from the wind data. Then a horizontal axis wind turbine has been designed for the selected site. For the simulation of power in replaced of designed wind turbine a remote controlled motor has been coupled with a generator. The motor speed has been controlled by PWM signal in its ten steps. Couple microcontrollers have been used for the simulation. High radio frequency remote have been designed to control the motor. At any step, the motor RPM, generator output voltage and switch position have been digitally displayed in the LCD display screen.

Size at first sexual maturity, fecundity, length-weight and length-length relationships ofPuntius sophore(Cyprinidae) in Bangladeshi waters

The present study describes the size at first sexual maturity, fecundity, length–weight (LWRs) and length–length relationships (LLRs) of the pool barb, Puntius sophore, using data obtained from different geographical locations in Bangladesh. A total of 905 specimens were caught by traditional fishing gear from March 2010 to February 2011. Additionally, a total of 121 females were collected from a commercial catch of the Padma River during June–July 2011 to estimate size at first maturity and to determine fecundity. Total length (TL), fork length (FL) and standard length (SL) were measured with digital slide calipers. Individual body weights (BW) were determined for all specimens, and gonad weights (GW) from 121 females were weighed to an accuracy of 0.001 g. The female gonadosomatic index (GSI) was calculated as [GSI (%) = (GW/BW) × 100]. Female size at first maturity was estimated using GSI and TL as indicators, and estimated as 5.00 cm TL in the Padma River. Specimens larger than 5.00 cm TL were used to determine fecundity. Mean total fecundity was 5300 ± 2700, ranging from 1580 to 16590. A positive exponential correlation was recorded between total fecundity and total length (r2 = 0.421). Relative fecundity ranged from 466 to 4036 (mean 1100 ± 580) in the Padma River. The LWR of pooled data for sexes combined was estimated as BW = 0.0155 TL2.98 as ancova revealed no significant differences in LWRs between rivers (P > 0.05). All LLRs were highly correlated (r2 > 0.983; P < 0.001), and ancova analyses further indicated that LLRs did not differ between rivers (P > 0.05). These results will help in further studies on the population assessment of the species.

Genetic population structure of the malaria vector Anopheles baimaii in north-east India using mitochondrial DNA

BackgroundAnopheles baimaii is a primary vector of human malaria in the forest settings of Southeast Asia including the north-eastern region of India. Here, the genetic population structure and the basic population genetic parameters of An. baimaii in north-east India were estimated using DNA sequences of the mitochondrial cytochrome oxidase sub unit II (COII) gene.MethodsAnopheles baimaii were collected from 26 geo-referenced locations across the seven north-east Indian states and the COII gene was sequenced from 176 individuals across these sites. Fifty-seven COII sequences of An. baimaii from six locations in Bangladesh, Myanmar and Thailand from a previous study were added to this dataset. Altogether, 233 sequences were grouped into eight population groups, to facilitate analyses of genetic diversity, population structure and population history.ResultsA star-shaped median joining haplotype network, unimodal mismatch distribution and significantly negative neutrality tests indicated population expansion in An. baimaii with the start of expansion estimated to be ~0.243 million years before present (MYBP) in north-east India. The populations of An. baimaii from north-east India had the highest haplotype and nucleotide diversity with all other populations having a subset of this diversity, likely as the result of range expansion from north-east India. The north-east Indian populations were genetically distinct from those in Bangladesh, Myanmar and Thailand, indicating that mountains, such as the Arakan mountain range between north-east India and Myanmar, are a significant barrier to gene flow. Within north-east India, there was no genetic differentiation among populations with the exception of the Central 2 population in the Barail hills area that was significantly differentiated from other populations.ConclusionsThe high genetic distinctiveness of the Central 2 population in the Barail hills area of the north-east India should be confirmed and its epidemiological significance further investigated. The lack of genetic population structure in the other north-east Indian populations likely reflects large population sizes of An. baimaii that, historically, were able to disperse through continuous forest habitats in the north-east India. Additional markers and analytical approaches are required to determine if recent deforestation is now preventing ongoing gene flow. Until such information is acquired, An. baimaii in north-east India should be treated as a single unit for the implementation of vector control measures.

Impact of climate change on development phases of winter rice in Bangladesh

Impact of climate change on development phases of rice is one of the major concern issues due to yield reduction. In the present study, development phases of winter rice (boro rice) of BR3 and BR14 varieties for the years 2008, 2030, 2050 and 2070 have been simulated for 12 major rice growing Agro-Ecological Zones (AEZs) of Bangladesh using DSSAT model. Available data on soil and hydrologic characteristics of these locations, and typical crop management practices for boro rice were used. The weather data required for the model were generated for the selected years and for the selected locations using the regional climate model PRECIS. Compared to 2008, the model predicted average reductions in development phases in days of BR3 variety for the selected 12 locations were 1 in Emergence (E) to End Juvenile (EJ) phase, 1 in Panicle Inition (PI) to End Leaf Growth (ELG) and 1 in Grain Filling Phase (GFP) phase during 2030; 4 in E to EJ, 1 in EJ to PI, 3 in PI to ELG and 2 GFP phase for the year 2050 and 7 in E to EJ, 3 in EJ to PI, 5 in PI to ELG and 3 GFP in 2070. Similar results were also found for BR14 variety for the selected locations in Bangladesh. Therefore, developing new rice varieties with considering climatic adaptive, proper growing period should be maintained.

Iron and aluminium based adsorption strategies for removing arsenic from water

Arsenic is a commonly occurring toxic metal in natural systems and is the root cause of many diseases and disorders. Occurrence of arsenic contaminated water is reported from several countries all over the world. A great deal of research over recent decades has been motivated by the requirement to lower the concentration of arsenic in drinking water and the need to develop low cost techniques which can be widely applied for arsenic removal from contaminated water. This review briefly presents iron and aluminium based adsorbents for arsenic removal. Studies carried out on oxidation of arsenic(III) to arsenic(V) employing various oxidising agents to facilitate arsenic removal are briefly mentioned. Effects of competing ions, As:Fe ratios, arsenic(V) vs. arsenic(III) removal using ferrihydrite as the adsorbent have been discussed. Recent efforts made for investigating arsenic adsorption on iron hydroxides/oxyhydroxides/oxides such as granular ferric hydroxide, goethite, akaganeite, magnetite and haematite have been reviewed. The adsorption behaviours of activated alumina, gibbsite, bauxite, activated bauxite, layered double hydroxides are discussed. Point-of-use adsorptive remediation methods indicate that Sono Arsenic filter and Kanchan™ Arsenic filter are in operation at various locations of Bangladesh and Nepal. The relative merits and demerits of such filters have been discussed. Evaluation of kits used for at-site arsenic estimation by various researchers also forms a part of this review.