Estimating Revenue Losses Evolve from Tax Evasions in Bangladesh:

This empirical study estimates the revenue losses derived from different categories of taxpayers who used Self-assessment System (SAS) under direct taxation in Bangladesh. Even though a small portion of populations live in urban areas (over 80 percent live in rural areas) that used the SAS in filing tax-returns, they significantly contributed to the problem. Revenue loss due to these taxpayers’ noncompliance with laws of income is a growing problem where the past five year (2000-2004) data statistics suggested that the Private Ltd Companies and Public Ltd Companies contributed significantly to accelerating the problem. With governmental ongoing various measures including the provision of SAS that was designed to encourage taxpayers for compliance, the tax-evasion issue in Bangladesh is critical and it deserves attention without delay.

Applying Data Augmentation to Handwritten Arabic Numeral Recognition Using Deep Learning Neural Networks

Handwritten character recognition has been the center of research and a benchmark problem in the sector of pattern recognition and artificial intelligence, and it continues to be a challenging research topic. Due to its enormous application many works have been done in this field focusing on different languages. Arabic, being a diversified language has a huge scope of research with potential challenges. A convolutional neural network model for recognizing handwritten numerals in Arabic language is proposed in this paper, where the dataset is subject to various augmentation in order to add robustness needed for deep learning approach. The proposed method is empowered by the presence of dropout regularization to do away with the problem of data overfitting. Moreover, suitable change is introduced in activation function to overcome the problem of vanishing gradient. With these modifications, the proposed system achieves an accuracy of 99.4\% which performs better than every previous work on the dataset.Comment: 5 pages, 6 figures, 3 table

Epidémiologie de la brucellose bovine chez les ruminants domestiques et chez l’homme au Bangladesh

Background Brucellosis is an ancient and one of the world’s most widespread zoonotic diseases affecting both, public health and animal production. It is endemic in many developing countries of Asia, Africa and Latin America including Bangladesh. Since the first report in 1970, a lot of brucellosis seroprevalence reports are available in cattle, goats, sheep and humans in Bangladesh. Most of the previously reported prevalence studies were based on non-random samples, which may not give a true representation of the status of the disease in respective populations. Some authors also investigated the risk factors in cattle. The tests used for the diagnosis of brucellosis in domestic ruminants and humans are imperfect and their performance was not evaluated in Bangladesh. The true prevalence of brucellosis in domestic ruminants is not known and is essential for analyzing the impact of this disease in domestic ruminants in Bangladesh. Indeed, when diagnostic tests are used without evaluating their performance in a context usually generate unreliable results, which in turn may lead to wrong epidemiological inferences. In addition, information on risk factors of brucellosis in humans and animals is also scarce. Moreover, the different species of Brucella prevalent in animals is scarce and not known in humans in Bangladesh. The overall objective of this thesis was to investigate the epidemiology of brucellosis in humans and domestic ruminants in Bangladesh in terms of the evaluation of commonly used diagnostic tests, estimation of true prevalence, identification of risk factors and detection of Brucella species in order to provide information that will guide the selection of appropriate control strategies. Study design and data analysis Sampling To collect random samples of animals a system of map digitization and selection of one geographical point from selected unions (Sub-Upazilla) using a hand held GPS machine was used. Blood (milk also where applicable) samples were then collected from livestock farmers and their animals within 0.5 km of the selected points. A convenient blood sample of butchers, dairy hands and veterinary practitioners were collected from Dhaka and Mymensingh districts. The sera of pyretic humans were collected from Mymensingh Medical College hospital randomly once in a week. Random milk samples were collected from Sirajgonj and Chittagong districts. Systematic random milk and blood samples of cattle including breeding bulls (semen also) of central cattle breeding and dairy farm (CCBDF) were also collected. Milk and blood samples of gayals of a herd in regional Bangladesh Livestock Research Institute at Naikhonchari, Bandarban were also collected. Convenient samples of placenta and vaginal swabs were also collected from Mymensingh district. Data collection and Analysis Data on serology was generated by using Rose Bengal test (RBT), Slow Agglutination test (SAT) /Standard tube agglutination test (STAT) (animals/humans) and indirect enzyme linked immunosorbent assay (iELISA). Animal, their herd level data and human data on potential risk factors were collected using a pretested questionnaire. The data was stored in Microsoft Excels worksheets and transferred to respective software for analysis. To estimate true prevalence and evaluate three conditionally dependent serological tests, Bayesian latent class models were used. Random effect and Firth’s logistic regression analyses were used to determine the risk factors of human brucellosis. The STATA, R and OpenBUGS softwares were used for data analyses. Staining, culture, genus and species-specific real time PCR assays were applied to isolate and to detect Brucella Spp./DNA in seropositive human sera and animal samples. Main results: Only 0.29% (95% CI: 0.06-0.86) cattle were acutely infected whereas 0.49% (95% CI: 0.16- 8 1.1) were chronically infected with brucellosis in Mymensingh. On the other hand, in CCBDF 15.58% (95% CI:11.89-19.89) cattle were acutely infected with brucellosis and only 3.2%(95%CI: 1.63-5.72) were chronically infected. The true prevalence of brucellosis among cattle in Mymensingh and CCBDF were 0.3% (95%CI: 0.03-0.7) and 20.5% (95% CI: 16.4-26.3) respectively. The performance of iELISA was best in both Mymensingh and CCBDF with the sensitivity of 90.5% and 91.3% and specificity of 99.3% and 99.2% respectively. The performance of RBT was better in Mymensingh than CCBDF with 81.0% and 76.1% sensitivity and 99.0% and 95.6% specificity respectively. Similar to RBT, the performance of SAT was also better in Mymensingh than CCBDF with 63.5% and 79.7% sensitivity and 98.6% and 95.3% specificity respectively. Through this test validation study, a new cut-off of 5 IU/ml for iELISA was recommended both in low (as at Mymensingh) and high prevalence scenarios in cattle populations (as at CCBDF) for routine screening. It was recommended to do nothing for the control of bovine brucellosis under small-scale dairy and subsistence management systems in Bangladesh. However, vaccination should be applied in herds where the prevalence is very high as like CCBDF. The true prevalence of brucellosis in goats and sheep were estimated as 1% (95% CI): 0.7–1.8) and 1.2% (95% CI: 0.6–2.2) respectively. The sensitivity of iELISA was 92.9% in goats and 92.0% in sheep with corresponding specificities of 96.5% and 99.5% respectively. The sensitivity and specificity estimates of RBT were 80.2% and 99.6% in goats and 82.8% and 98.3% in sheep. The sensitivity and specificity of SAT were 57.1% and 99.3% in goats and 72.0% and 98.6% in sheep. The prevalence of brucellosis in occupationally exposed people (HROG) using three tests was observed to be 4.4% based on a parallel interpretation. The results of the multiple random effects logistic regression analysis with random intercept for district revealed that the odds of brucellosis seropositivity among individuals who had been in contact with livestock for more than 26 years was about 14 times higher as compared to those who had less than 5 years of contact with livestock. In addition, when the contact was with goats, the odds of brucellosis seropositivity were about 60 times higher as compared to when contact was with cattle only. The seroprevalence of brucellosis among patients with pyrexia of unknown origin (PUO) was estimated to be 2.7% (95% CI: 1.2-5.2). The age, residence, type of patient, contact with animals, type of animal handled, arthralgia and backache were found to be significantly associated with a positive serological result in bivariable Firth’s logistic regression. Brucella abortus was detected from seropositive pyretic patients. Conclusion: The true exposure prevalence of brucellosis in cattle under small-scale dairy and subsistence/backyard management systems is very low (0.3%; 95% CI: 0.03-0.7). The active/acute infection is also very low (0.29%: 95% CI: 0.06-0.86) and similar to true exposure prevalence. The brucellosis in cattle under such management system is naturally controlled and further control program is not recommended considering the poor socioeconomic conditions. The true exposure prevalence of brucellosis in CCBDF is very high (20.5%; 95% CI: 16.4-26.3). The acute infection in this farm is also very high (15.58%; 95% CI: 11.89-19.89). Immediate control measures by initiating calf hood (female calf) vaccination are recommended to protect a valuable herd which also provides frozen semen for artificial insemination all over the country. The SAT and iELISA may simultaneously be applied to know the stage of brucellosis infection in domestic ruminants in high prevalence scenarios. The true exposure prevalence of brucellosis in goats and sheep are also low and around 1%. Due to lower positive predictive value, these test results should be interpreted with caution to avoid misleading information. Breeding bulls used for artificial insemination all over the country were found to be infected with brucellosis. Brucellosis is not a serious problem for the general population in Bangladesh as drinking raw milk and milk products is unusual and not a risk factor. The apparent prevalence of brucellosis in high risk occupationally exposed people (4.4%; 95% CI: 2.8-6.6) and in pyretic patients (2.7%; 95% CI: 1.2-5.2) are also low. The RBT may be applied as a screening test in humans having signs and symptoms of brucellosis along with the history of animal contact. In case of suspicion, genus or species specific rt PCR may be applied for confirmation. Only B. abortus DNA was amplified from 19 seropositive human samples (both HROG and PUO) and six animal samples (3 cows milk, one goat milk, one gayal milk and one bull semen). No Brucella like organism was observed under microscope in stained smears. Similarly, no Brucella organism was isolated from any of the clinical samples

Monthly and diurnal variations of limnological conditions of two ponds

A study on monthly and diurnal changes of limnological conditions of two ponds was conducted in the Bangladesh Agricultural University campus, Mymensingh. The research work was performed by studying the limnological parameters such as transparency, temperature, dissolved oxygen, free carbon dioxide, pH, total alkalinity, nitrate-nitrogen, phosphate-phosphorus and plankton. Diurnal variations of physico-chemical factors were studied fortnightly at 6 hrs intervals at 6 a.m., 12 noon, 6 p.m. and 12 midnight. The amounts of transparency, dissolved oxygen and pH were higher during winter months than in summer months in both the ponds. Transparency, water temperature, total alkalinity, NO3-N and PO4-P were higher during summer months than in winter months in both the ponds. But the amount of free carbon dioxide was higher during winter months than in summer months in pond 1 while in pond 2 the amount of free carbon dioxide was higher during summer months than in winter months. Qualitative and quantitative monthly variations of phytoplankton and zooplankton were observed in both the ponds during the study period. The highest amount of dissolved oxygen, pH and total alkalinity were recorded at 6 p.m. and the lowest amounts of those at 6 a.m. in both the ponds. The highest temperature was recorded at 12 noon and the lowest at 12 midnight. But the highest amount of free carbon dioxide was recorded at 6 a.m. and the lowest at 6 p.m. in both the ponds. All the factors showed appreciable diel variations throughout the study period, which indicate that the ponds are productive.Int. J. Agril. Res. Innov. & Tech. 7 (1): 14-20, June, 201

Synergistic Effects of Processing and Nanofiber Reinforcement on the mechanical and Ferroelectric Performance of Geopolymer Matrix Composites

tThis study involved the evaluation of mechanical and ferroelectric properties of a new classof nanofiller infused inorganic polymer (geopolymer, GP). To evaluate the mechanical per-formance, compressive strength and fracture resistance of neat and nanofillers infused GPwere studied at various treatment temperatures. It was found that, addition of 5 vol% alu-mina nanofiber (ANF), increased compressive strength and modulus by over 30% and 60%,respectively, while it increased fracture toughness (KIC) by over 60% compared to the baselinespecimens. Simultaneously, ferroelectric properties were investigated at various treatmenttemperatures (250◦C, 650◦C and 870◦C). Remarkably, higher ferroelectric hysteresis wasobserved with the GP treated at 870◦C and remnant polarization increased with the addi-tion of alumina nanofiber. Scanning Electron Microscopy confirmed that neat materials arecomposed of particles embedded into the poly-condensed matrix, where particle natureexisted until the treatment temperature reached above 870◦C. X-ray diffraction analysissuggests that, baseline geopolymer started becoming crystalline while the particle naturegradually disappeared with heating at or beyond 870◦C. The bonding between the polymerand alumina nanofiber tends to be stronger with increasing treatment temperature. Theincrease in KICwith the addition of 2 vol% and 5 vol% alumina nanofibers (ANF) is due tohomogeneous dispersion of high interfacial strength nanofillers, which essentially createstrong crack bridging and crack deflection effect. The increase in ferroelectric hysteresisis potentially due to the formation of hierarchical order and domain reorientation of thematerials

Expression of Heterosis for Productive Traits in Bottle Gourd Hybrids

A study was conducted in bottle gourd to estimate the magnitude of heterosis for yield and its thirteen yield related components. Twenty one bottle gourd hybrids generated from 7 × 7 diallel cross (excluding reciprocals) along with their seven parents evaluated in a Randomized Block Design with three replication at at the Olericulture Division of Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh during 2018-19. Most of the crosses showed significant heterobeltiosis for earliness. The highest heterobeltiotic effect was observed in the cross P2XP7 and P4XP7. The best heterotic cross for fruit length was P4XP5. Maximum heterotic effect in respect of fruit number per plant was found in the cross P1XP6 and P4XP6. In terms of yield per plant the highest heterobeltiosis was shown by the crosses P3XP4, P3XP5, P4XP5 and P4XP7. In the overall analysis, both additive and non-additive gene actions were found important with predominance of the additive gene effects in the inheritance of bottle gourd

Fly Ash Based Geopolymer for High Temperature and High Compressive Strength Applications in Aggressive Environment

Geopolymers are the results of geosynthetic reactions between aluminosilicates and strong bases. This results in chemical bonds between aluminum (Al), Silicon (Si)and oxygen (O) composing polymer rings in tetrahedral coordination. These bonds give them widespread useful applications such as high heat bearing ceramics, and base construction material whilst being far more environmentally conscious. The purpose of the experiment is to examine the effect of Silicon Carbide whisker and inorganic glass particles on thermal and mechanical properties of Geopolymers. This study will help understand the effect of various compositions and concentrations of SiO2 in mechanical strength. In this experiment, the major source of Aluminosilicate material to make the geopolymer paste was fly ash, potassium hydroxide, Potassium silicate, Glass silica and water. A variety of concentrations of Silicon Carbide Whisker and glass particles will be added into geopolymer paste in order to evaluate their performance specifically on compressive strength and thermal conductivity. These are essential properties of cementing materials in energy or heat extraction process. Therefore, the material under investigation has potential for geothermal energy extraction and subterranean structures

Phosphorus Cycling between Sediment and Overlying Water in Ben Chifely Reservoir, Australia under Simulated Core Incubation

The flux of soluble reactive phosphorus (SRP) was estimated under simulated oxic, anoxic and aerated conditions in sediment cores collected from two sites in a meso-eutrophic reservoir that differ in depth and limnological characteristics. Hypolimnetic accumulation and the concentration of P in various sediment fractions were also studied to determine the factors and processes influencing SRP flux at the sediment-water interface. The average release of SRP under anoxic incubation varied between 16 - 70 µmol/m2/day and 20 - 94 µmol/m2/day in shallow and deep-water sites respectively. On the other hand, SRP was almost entirely lost to the sediment during simulated oxic or aerated experiments. Temperature influence on P release from the sediment was significant and the increment is considerable at water temperature above 20oC. The reservoir sediment contained a large proportion of iron and aluminum bound P (Fe and Al-P). Fe and P ratio in the sediment exceeded 15 indicating high retention capacity of P by the sediment. Besides, the high amount of Fe and Al-P in the sediment reflects redox dependent P mobilization. Therefore, management needs targeting retention capacity of the sediment and alteration of anoxic condition in the hypolimnion during warmer months

Simultaneous effects of rice husk silica and silicon carbide whiskers on the mechanical properties and morphology of sodium geopolymer

The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived silica and commercially available silicon carbide whiskers. Results show that rice husk ashes–derived spherical silica nanoparticles reduced nano-porosity of the geopolymers by ∼20% and doubled the compressive strength. The simultaneous additions of rice husk ashes and silicon carbide whiskers resulted in flexural strength improvement by ∼27% and ∼97%, respectively. The increase in compressive strength due to the inclusion of silica nanoparticles is related to the reduction in porosity. The increase in flexural strength due to simultaneous inclusion of silica and silicon carbide whiskers suggest that silica particles are compatible with the metakaolin-based geopolymers, which is effective in consolidation. Finally, microscopy suggest that silicon carbide whiskers are effective in increasing bridged network and crack resistance