Age and growth of hilsa shad, Tenualosa ilisha (Hamilton, 1822) of the river Tentulia in Bangladesh

This study was carried out on age and growth of hilsa shad, Tenualosa ilisha in river Tentulia in Bhola district using monthly samples from January to December 2009 by checking annual rings or growth checks on hard parts. Age and growth of T. ilisha got progressed by direct fit of length frequency data both to standard and to modified von Bertalanffy growth models with ELEFAN I procedure where the predicted maximum total length were (TL∞) 41.88 cm for male and 52.40 cm for female. Powell-Wetherall procedure gave an initial asymptotic total length (TL∞) for both male and female 40.42 cm, 50.61 cm respectively. The values of Z/K were 3.362 for male and 2.626 for female. The growth co-efficient (K) was obtained as 1.40 year-1 for male and 1.00 year-1 for female. The von Bertalanffy growth equations in terms of body weight (BW) for both male and female were BWt=799.26[1-exp{-1.40(t+0.002)}]3 and BWt=1717.82[1-exp{-0.99(t+0.013)}]3 respectively. The length-weight relationship for both sexes were BW=0.0101 TL 3.02 for male and BW=0.0086 TL 3.08 for female. The value of coefficient of determination (R2) was estimated for both male and female species were 0.969 and 0.968

A Comprehensive Dataset on Bangladeshi University Students' Mental Health

This dataset comprises mental health data from 1977 Bangladeshi university students across 15 top universities, collected from November to December 2023 using Google Forms. It includes assessments of academic anxiety, stress, and depression using widely used psychometric scales. The structured questionnaire covers sociodemographic variables and their associations, facilitating comprehensive analysis. Statistical analysis yielded satisfactory internal consistency (Cronbach’s alpha: 0.79), with anonymized participant data valuable for policymakers.</p

Surface water quality profiling using the water quality index, pollution index and statistical methods: A critical review

Surface water is heavily exposed to contamination as this is the ubiquitous source for most of the water needs. This situation is exaggerated by the excessive population, heavy industrialization, rapid urbanization, and improper sanitation. Comprehensive measurement and knowledge extraction of surface water quality is therefore pivotal for ensuring safe and hygienic water use. Consequently, surface water quality profiling has received remarkable academic attention in recent decades that produces an ample amount of research results. This study, therefore, conducts a comprehensive systematic literature review to summarize and structure the existing literature and to identify current research trends and hotspots. Reported results suggest that the terrain of fresh surface water includes 13 distinct water sources that are predominantly used in 5 sectors. These sectors often cause the water pollution in the form of industrial effluents, agricultural runoffs, and domestic sewage. For profiling the water quality, around 23 Water Quality Index (WQI) models, and 10 Pollution Index (PI) models are used in research. These models often use several water quality parameters. This study reports an exhaustive taxonomy of 69 prominent quality parameters in three categories which will support their adoption for these models. Finally, the limitations of the current manual water quality measurement approaches are summarized to propose a set of seven requirements for the tech-intensive water quality profiling research and system development

Susceptibility of field-collected Phlebotomus argentipes (Diptera: Psychodidae) sand flies from Bangladesh and Nepal to different insecticides

Abstract Background The sand fly Phlebotomus argentipes is the vector for visceral leishmaniasis (VL) in the Indian sub-continent. In Bangladesh since 2012, indoor residual spraying (IRS) was applied in VL endemic areas using deltamethrin. In Nepal, IRS was initiated in 1992 for VL vector control using lambda-cyhalothrin. Irrational use of insecticides may lead to vector resistance but very little information on this subject is available in both countries. The objective of this study was to generate information on the susceptibility of the vector sand fly, P. argentipes to insecticide, in support of the VL elimination initiative on the Indian sub-continent. Methods Susceptibility tests were performed using WHO test kits following the standard procedures regarding alpha cypermethrin (0.05%), deltamethrin (0.05%), lambda-cyhalothrin (0.05%), permethrin (0.75%), malathion (5%) and bendiocarb (0.1%) in six upazilas (sub-districts) in Bangladesh. In Nepal, the tests were performed for two insecticides: alpha cypermethrin (0.05%) and deltamethrin (0.05%). Adult P. argentipes sand flies were collected in Bangladesh from six VL endemic upazilas (sub-districts) and in Nepal from three endemic districts using manual aspirators. Results The results show that VL vectors were highly susceptible to all insecticides at 60 minutes of exposure in both countries. In Bangladesh, corrected mortality was 100% at 15 minutes as well as 30 minutes of exposure. The study sites in Nepal, however, showed some diverse results, with a mortality rate less than 90% for 15 minutes of exposure with alpha cypermethrin and deltamethrin in two districts but was above 95% after 30 minutes of exposure. Conclusions These results suggest that the insecticides tested can still be used in the national programmes of Bangladesh and Nepal. However, insecticide rotation should be performed to mitigate the possible development of insecticide resistance. Periodic susceptibility tests should be performed by the countries to get timely alerts regarding insecticide resistance

Control of Phlebotomus argentipes (Diptera: Psychodidae) sand fly in Bangladesh: a cluster randomized controlled trial

Background: A number of studies on visceral leishmaniasis (VL) vector control have been conducted during the past decade, sometimes came to very different conclusion. The present study on a large sample investigated different options which are partially unexplored including: (1) indoor residual spraying (IRS) with alpha cypermethrin 5WP; (2) long lasting insecticide impregnated bed-net (LLIN); (3) impregnation of local bed-nets with slow release insecticide K-O TAB 1-2-3 (KOTAB); (4) insecticide spraying in potential breeding sites outside of house using chlorpyrifos 20EC (OUT) and different combinations of the above. Methods: The study was a cluster randomized controlled trial where 3089 houses from 11 villages were divided into 10 sections, each section with 6 clusters and each cluster having approximately 50 houses. Based on vector density (males plus females) during baseline survey, the 60 clusters were categorized into 3 groups: (1) high, (2) medium and (3) low. Each group had 20 clusters. From these three groups, 6 clusters (about 300 households) were randomly selected for each type of intervention and control arms. Vector density was measured before and 2, 4, 5, 7, 11, 14, 15, 18 and 22 months after intervention using CDC light traps. The impact of interventions was measured by using the difference-in-differences regression model. Results: A total of 17,434 sand flies were collected at baseline and during the surveys conducted over 9 months following the baseline measurements. At baseline, the average P. argentipes density per household was 10.6 (SD = 11.5) in the control arm and 7.3 (SD = 8.46) to 11.5 (SD = 20.2) in intervention arms. The intervention results presented as the range of percent reductions of sand flies (males plus females) and rate ratios in 9 measurements over 22 months. Among single type interventions, the effect of IRS with 2 rounds of spraying (applied by the research team) ranged from 13% to 75% reduction of P. argentipes density compared to the control arm (rate-ratio [RR] ranged from 0.25 to 0.87). LLINs caused a vector reduction of 9% to 78% (RR, 0.22 to 0.91). KOTAB reduced vectors by 4% to 73% (RR, 0.27 to 0.96). The combination of LLIN and OUT led to a vector reduction of 26% to 86% (RR, 0.14 to 0.74). The reduction for the combination of IRS and OUT was 8% to 88% (RR, 0.12 to 0.92). IRS and LLIN combined resulted in a vector reduction of 13% to 85% (RR, 0.15 to 0.77). The IRS and KOTAB combination reduced vector densities by 16% to 86% (RR, 0.14 to 0.84). Some intermediate measurements for KOTAB alone and for IRS plus LLIN; and IRS plus KOTAB were not statistically significant. The bioassays on sprayed surfaces or netting materials showed favourable results (>80% mortality) for 22 months (IRS tested for 12 months). In the KOTAB, a gradual decline was observed after 6 months. Conclusions: LLIN and OUT was the best combination to reduce VL vector densities for 22 months or longer. Operationally, this is much easier to apply than IRS. A cost analysis of the preferred tools will follow. The relationship between vector density (males plus females) and leishmaniasis incidence should be investigated, and this will require estimates of the Entomological Inoculation Rate

Study design.

<p>[Note: <u>Interventions:</u> IRS = A; LLIN = B; Local bednet impregnated with KO TAB 1-2-3 = C; Possible breeding places (outside of home) sprayed with Clorophyrephos = D; A+B = E; A+C = F; B+D = G; C+D = H; A+D = I and J = Control (no intervention)]</p

Study areas.

<p>Study areas.</p

Total number of sand flies collected in all study houses during study period by species, sex, gravidity, feeding status in Fulbaria, Mymensingh, Bangladesh.

<p>Total number of sand flies collected in all study houses during study period by species, sex, gravidity, feeding status in Fulbaria, Mymensingh, Bangladesh.</p

Control of <i>Phlebotomus argentipes</i> (Diptera: Psychodidae) sand fly in Bangladesh: A cluster randomized controlled trial

<div><p>Background</p><p>A number of studies on visceral leishmaniasis (VL) vector control have been conducted during the past decade, sometimes came to very different conclusion. The present study on a large sample investigated different options which are partially unexplored including: (1) indoor residual spraying (IRS) with alpha cypermethrin 5WP; (2) long lasting insecticide impregnated bed-net (LLIN); (3) impregnation of local bed-nets with slow release insecticide K-O TAB 1-2-3 (KOTAB); (4) insecticide spraying in potential breeding sites outside of house using chlorpyrifos 20EC (OUT) and different combinations of the above.</p><p>Methods</p><p>The study was a cluster randomized controlled trial where 3089 houses from 11 villages were divided into 10 sections, each section with 6 clusters and each cluster having approximately 50 houses. Based on vector density (males plus females) during baseline survey, the 60 clusters were categorized into 3 groups: (1) high, (2) medium and (3) low. Each group had 20 clusters. From these three groups, 6 clusters (about 300 households) were randomly selected for each type of intervention and control arms. Vector density was measured before and 2, 4, 5, 7, 11, 14, 15, 18 and 22 months after intervention using CDC light traps. The impact of interventions was measured by using the difference-in-differences regression model.</p><p>Results</p><p>A total of 17,434 sand flies were collected at baseline and during the surveys conducted over 9 months following the baseline measurements. At baseline, the average <i>P</i>. <i>argentipes</i> density per household was 10.6 (SD = 11.5) in the control arm and 7.3 (SD = 8.46) to 11.5 (SD = 20.2) in intervention arms. The intervention results presented as the range of percent reductions of sand flies (males plus females) and rate ratios in 9 measurements over 22 months. Among single type interventions, the effect of IRS with 2 rounds of spraying (applied by the research team) ranged from 13% to 75% reduction of <i>P</i>. <i>argentipes</i> density compared to the control arm (rate-ratio [RR] ranged from 0.25 to 0.87). LLINs caused a vector reduction of 9% to 78% (RR, 0.22 to 0.91). KOTAB reduced vectors by 4% to 73% (RR, 0.27 to 0.96). The combination of LLIN and OUT led to a vector reduction of 26% to 86% (RR, 0.14 to 0.74). The reduction for the combination of IRS and OUT was 8% to 88% (RR, 0.12 to 0.92). IRS and LLIN combined resulted in a vector reduction of 13% to 85% (RR, 0.15 to 0.77). The IRS and KOTAB combination reduced vector densities by 16% to 86% (RR, 0.14 to 0.84). Some intermediate measurements for KOTAB alone and for IRS plus LLIN; and IRS plus KOTAB were not statistically significant. The bioassays on sprayed surfaces or netting materials showed favourable results (>80% mortality) for 22 months (IRS tested for 12 months). In the KOTAB, a gradual decline was observed after 6 months.</p><p>Conclusions</p><p>LLIN and OUT was the best combination to reduce VL vector densities for 22 months or longer. Operationally, this is much easier to apply than IRS. A cost analysis of the preferred tools will follow. The relationship between vector density (males plus females) and leishmaniasis incidence should be investigated, and this will require estimates of the Entomological Inoculation Rate.</p></div

Benefit of interventions attributed by reduction of <i>P</i>. <i>argentipes</i> sand fly density at household level.

<p>Benefit of interventions attributed by reduction of <i>P</i>. <i>argentipes</i> sand fly density at household level.</p