Effects of control of C/N ratio by low-cost carbohydrate addition on water quality and pond ecology in freshwater prawn Macrobrachium rosenbergii post-larvae nursing system

An experiment was conducted to evaluate the effects of control of carbon/nitrogen ratio (C/N ratio) by addition of low cost carbohydrate to the water column on water quality and pond ecology in freshwater prawn Macrobrachium rosenbergii post-larvae nursing system. In this experiment, two level of dietary protein 20% and 35% without carbohydrate addition (‘P20' and ‘P35') and with carbohydrate addition (‘P20+CH' and ‘P35+CH') were compared in small ponds of 40 m² area stocked with 20 post-larvae (0.021 ± 0.001g) per m² . Maize flour was used as low cost carbohydrate and applied to the water column followed by the first feeding during the day. The addition of carbohydrate significantly reduced (p0.05) of total phytoplankton and zooplankton among the treatments. Survival rate of prawn was significantly lowest (p0.05) was observed between P20+CH and P35 treatments. Control of C/N ratio by the addition of low-cost carbohydrate to the pond water column benefited the freshwater prawn nursing practices in three ways (1) increased heterotrophic bacterial growth supplying bacterial protein augment the prawn post-larvae growth performances, (2) reduced demand for supplemental feed protein and subsequent reduction in feed cost and (3) reduced toxic NH sub(3)-N and NO sub(2)-N levels in pond nursing system

Cloning and expression of highly pathogenic avian influenza virus full-length nonstructural gene in Pichia pastoris.

Avian influenza (AI) is a highly contagious and rapidly evolving pathogen of major concern to the poultry industry and human health. Rapid and accurate detection of avian influenza virus is a necessary tool for control of outbreaks and surveillance. The AI virus A/Chicken/Malaysia/5858/2004 (H5N1) was used as a template to produce DNA clones of the full-length NS1 genes via reverse transcriptase synthesis of cDNA by PCR amplification of the NS1 region. Products were cloned into pCR2.0 TOPO TA plasmid and subsequently subcloned into pPICZA vector to construct a recombinant plasmid. Recombinant plasmid designated as pPICZA-NS1 gene was confirmed by PCR colony screening, restriction enzyme digestion, and nucleotide sequence analysis. The recombinant plasmid was transformed into Pichia pastoris GS115 strain by electroporation, and expressed protein was identified by SDS-PAGE and western blotting. A recombinant protein of approximately ~28kDa was produced. The expressed protein was able to bind a rabbit polyclonal antibody of nonstructural protein (NS1) avian influenza virus H5N1. The result of the western blotting and solid-phase ELISA assay using H5N1 antibody indicated that the recombinant protein produced retained its antigenicity. This further indicates that Pichia pastoris could be an efficient expression system for a avian influenza virus nonstructural (NS1)

Induction of mitotic and meiotic gynogenesis and production of genetic clones in rohu, Labeo rohita Ham.

Studies were undertaken to produce genetic clones derived from all homozygous mitotic gynogenetic individuals in rohu, Labeo rohita Ham. ln view of this, attempts were made to interfere with the normal functioning of the spindle apparatus during the first mitotic cell division of developing eggs using heat shocks, there by leading to the induction of mitotic gynogenetic diploids in the F1 generation. Afterwards, viable mitotic gynogenetic alevins were reared and a selected mature female fish was used to obtain ovulated eggs which were fertilized later with UV-irradiated milt. Milt was diluted with Cortland’s solution and the sperm concentration was maintained at 10⁸/ml. The UV-irradiation was carried out for 2 minutes at the intensity of 200 to 250 µW/cm² at 28± 1°C. The optimal heat shock of 40°C for 2 minutes applied at 25 to 30 minutes a.f. was used to induce mitotic gynogenesis in first (F1) generation and at 3 to 5 minutes a.f. to induce meiotic gynogenesis in the second (F2) generation. The results obtained are presented and the light they shed on the timing of the mitotic and meiotic cell division in this species is discussed

Initiatives of Tropical Agroforestry to Sustainable Agriculture: A Case Study of Capasia Village, Northern Bangladesh

A relatively large percentage of the population in Bangladesh lives under the poverty line and is affected by the country's degrading natural resources. Agroforestry has been seen as one of the few options to lift people out of poverty. Research into the costs and benefits of agroforestry was undertaken in Capasia Village in Northern Bangladesh. Initial results indicate that agroforestry may not only be an optimal livelihood solution for poor farmers, biodiversity conservation and environmental sustainability but agroforestry systems also provide good economic rates of return. Thus the farmers who engage in agroforestry are benefited in different ways

Aquaculture for income and nutrition: Final report

The United States Agency for International Development-Aquaculture for Income and Nutrition (USAID-AIN) project, implemented by WorldFish, emphasized technology development for improved fish strains, and capacity building in hatcheries and nurseries for wider dissemination and uptake among small- and medium-scale household and commercial producers. Improving nutritional benefits from household aquaculture investment was also an important activity of the project. Specifically, AIN aimed to increase aquaculture production by developing hatcheries and nurseries, disseminating improved fish and shrimp seed, enhancing farm management skills of smallholder farmers, promoting new technologies to expand commercial aquaculture, developing backward and forward market linkages, supporting policy reform and building capacity of the public and private sectors, which resulted in increased productivity and revenue for farmers. This report also highlights the major achievements of the AIN project between 2011 and 2016

Hematology and serum chemistry reference values of stray dogs in Bangladesh

Hematology and serum chemistry values were obtained from 28 male and 22 female stray dogs in Chittagong Metropolitan area, Bangladesh. The goal of the study was to establish reference value for hematology and serum chemistry for these semi wild animals in relation to age, sex, reproductive stage and body condition. No significant differences were found for mean values of hemoglobin, packed cell volume, mean corpuscular hemoglobin concentration, white blood cell, differential leukocyte count, total protein, albumin, glucose, cholesterol, phosphorus and potassium among or between sexes, ages, reproductive states or body conditions. Significant differences were noted for erythrocyte sedimentation rate (p<0.02) between sexes. Among different age groups significant differences were found for total red blood cell count (p<0.001). Different body conditions have significant differences in red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin (p<0.001). Pregnant and non-pregnant females differed significantly in their red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin (p<0.001)

The effect of raising water temperature to 33°C in <i>Penaeus vannamei</i> juveniles at different stages of infection with white spot syndrome virus (WSSV)

This study investigated the effect of high water temperature (33°C) at different stages of infection with a highly virulent and low virulent white spot syndrome virus strain (WSSV Thai-1 and WSSV Viet) in Penaeus vannamei juveniles. Shrimp were inoculated intramuscularly with either a high dose (HD) or low dose (LD). Water temperature was kept either at continuously 27°C or switched from 27°C to 33°C at 0, 12 or 24 h post inoculation (hpi) for both strains and in addition at 48 or 96 hpi for WSSV Viet. The increased temperature 33°C was maintained till the end of the experiments (120–144 hpi with WSSV Thai-1 and 240 hpi with WSSV Viet). To determine the infection status at the moment of temperature increase, five shrimp that were kept continuously at 27 °C were euthanized at 0, 12, 24, 48 and 96 hpi with each dose of two strains. WSSV infections (viral antigen VP28) in dead and euthanized shrimp were demonstrated by indirect immunofluorescence.Shrimp inoculated with HD or LD of WSSV Thai-1 and kept continuously at 27°C till euthanasia were 100% viral antigen positive from 12 (HD) or 24 hpi (LD). Shrimp inoculated with WSSV Viet were 100% positive from 24 (HD) and 48 hpi (LD). Shrimp kept at 27°C, showed clinical signs from 24 (HD) or 24–36 hpi (LD) with both strains. Cumulative mortalities reached 100% with WSSV Thai-1 at 60 (HD) or 84–144 hpi (LD) and with WSSV Viet 100% at 216 hpi (HD) or 90% at 240 hpi (LD). Switch of temperature to 33°C from 0, 12 or 24 hpi was effective in reducing mortality of shrimp inoculated with the LD of both strains and with the HD of WSSV Viet. The switch to 33°C from 24 hpi with the Thai strain (HD) and from 48 and 96 hpi with the Viet strain (LD or HD) had no effect or even accelerated the mortality rate (80–100%). All shrimp were viral antigen positive at death and euthanasia (one shrimp LD WSSV Viet) when kept continuously at 27°C. All dead and euthanized shrimp kept at 33°C from 0 or 12 hpi were viral antigen negative. With 33°C from 24, 48 or 96 hpi, all dead shrimp were viral antigen positive and euthanized shrimp were negative.This study showed that 33°C is effective to prevent disease, reduce mortality and block WSSV replication, but only in the early stages of infection

Toll-like receptor-4 299Gly allele is associated with Guillain-Barre syndrome in Bangladesh

Objective: TLR4 plays an important role in the pathogenesis of Guillain-Barre syndrome (GBS). The relationships between TLR4 polymorphisms and susceptibility to GBS are poorly understood. We investigated the frequency and assessed the association of two single nucleotide polymorphisms (SNPs) in the extracellular domain of TLR4 (Asp299Gly and Thr399Ile) with disease susceptibility and the clinical features of GBS in a Bangladeshi cohort. Methods: A total of 290 subjects were included in this study: 141 patients with GBS and 149 unrelated healthy controls. The TLR4 polymorphisms Asp299Gly and Thr399Ile were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Results: The minor 299Gly allele was significantly associated with GBS susceptibility (P = 0.0137, OR = 1.97, 95% CI = 1.17–3.31), and was present at a significantly higher frequency in patients with the acute motor axonal neuropathy (AMAN) subtype of GBS (P = 0.0120, OR = 2.37, 95% CI = 1.26–4.47) than acute inflammatory demyelinating polyneuropathy (AIDP) subtype (P = 0.961, OR = 1.15, 95% CI = 0.38–3.48); when compared to healthy controls. The genotype frequency of the Asp299Gly polymorphism was not significantly different between patients with GBS and healthy controls. The Asp299-Thr399 haplotype was associated with a significantly lower risk of developing GBS (P = 0.0451, OR = 0.63, 95% CI = 0.40– 0.99). No association was observed between the Thr399Ile polymorphism and GBS disease susceptibility. Interpretation: The TLR4 minor 299Gly allele was associated with increased susceptibility to GBS and the axonal GBS subtype in the Bangladeshi population. However, no associations were observed between the genotypes of the Asp299Gly and Thr399Ile SNPs and antecedent C. jejuni infection or disease severity in Bangladeshi patients with GBS

Jamming at Zero Temperature and Zero Applied Stress: the Epitome of Disorder

We have studied how 2- and 3- dimensional systems made up of particles interacting with finite range, repulsive potentials jam (i.e., develop a yield stress in a disordered state) at zero temperature and applied stress. For each configuration, there is a unique jamming threshold, $\phi_c$, at which particles can no longer avoid each other and the bulk and shear moduli simultaneously become non-zero. The distribution of $\phi_c$ values becomes narrower as the system size increases, so that essentially all configurations jam at the same $\phi$ in the thermodynamic limit. This packing fraction corresponds to the previously measured value for random close-packing. In fact, our results provide a well-defined meaning for "random close-packing" in terms of the fraction of all phase space with inherent structures that jam. The jamming threshold, Point J, occurring at zero temperature and applied stress and at the random close-packing density, has properties reminiscent of an ordinary critical point. As Point J is approached from higher packing fractions, power-law scaling is found for many quantities. Moreover, near Point J, certain quantities no longer self-average, suggesting the existence of a length scale that diverges at J. However, Point J also differs from an ordinary critical point: the scaling exponents do not depend on dimension but do depend on the interparticle potential. Finally, as Point J is approached from high packing fractions, the density of vibrational states develops a large excess of low-frequency modes. All of these results suggest that Point J may control behavior in its vicinity-perhaps even at the glass transition.Comment: 21 pages, 20 figure

Protocol for tool wear measurement in micro-milling

Micro-milling yields small accurate parts quickly for electromechanical, aerospace, and medical applications. Due to their small size, micro-tools wear quickly and unpredictably therefore tool wear is difficult to measure and is poorly understood, leading to excessive tool changes and reduced productivity. This paper, therefore, proposes a new protocol for micro-tool wear measurement to overcome these problems. A strict set of criteria as found in an ISO standard is impractical for micro-milling research. The method herein allows comparisons to be made across materials and situations and detailed are certain criteria that must be fulfilled to achieve this. To evaluate the protocol micro-tools were used to machine three materials: brass, titanium and Hastelloy; and wear curves produced. Using the described protocol, these wear curves can be analysed similarly to those for larger tools. Profile analysis of the slots machined provides valuable information about tool wear where direct measurement is impossible. This new protocol presents a novel method for analysing and reporting tool wear for micro-end-mills, allowing them to be compared under different machining conditions and/or milling different materials, something not afforded by existing machining standards. The information can then be transferred to industrial applications, extending tool life and improving process efficiency