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Traditional diagnostic capabilities (serology and culture) are not enough to monitor the poultry infections efficiently. For effective control of poultry infections, a regular program incorporating simple and cost-effective molecular diagnostics is necessary. On this rationale, it is possible to present working molecular diagnostic technology that would work equally well in field as well as in the laboratory. Recently, the loop-mediated isothermal amplification (LAMP) assay has emerged as simple and inexpensive diagnostic tool for the molecular detection of various animal pathogens. To perform LAMP, no specialised instruments (e.g. thermal cycler) are required, permitting its use in developing countries. Various reliable LAMP assays have been reported for the detection of different poultry pathogens. However, still there is a need to improve the sensitivity, specificity, reproducibility, user-friendliness, delivery to end-user and affordability of LAMP assays. This article reviews current LAMP assays available for the molecular detection of important viral, bacterial and protozoan pathogens of poultry. It focuses on the various aspects of LAMP for the diagnosis of important poultry pathogens based upon pathogen type, specimen, target genes, LAMP primer types, detection limits, fluorescent detectors and LAMP chemistry used. This paper provides updates on principle, instrumentation, basic methodology, quantification capability, reagents and kits used currently in performing LAMP.
Cognitive dysfunction in depression is associated with poorer clinical outcomes and impaired psychosocial functioning. However, most treatments for depression do not specifically target cognition. Neurocognitive deficits such as memory and concentration problems tend to persist after mood symptoms recover. Improving cognition in depression requires a better understanding of brain systems implicated in depression. A comprehensive approach is warranted for refined methods of assessing and treating cognitive dysfunction in depression.
A theoretical study of an unsteady two-layered blood flow through a stenosed artery is presented in this article. The geometry of a rigid stenosed artery is assumed to be
-shaped. The flow regime is assumed to be laminar, unsteady and uni-directional. The characteristics of blood are modelled by the generalized Oldroyd-B non-Newtonian fluid model in the core region and a Newtonian fluid model in the periphery region. The governing partial differential equations are derived for each region by using mass and momentum conservation equations. In order to facilitate numerical solutions, the derived differential equations are nondimensionalized. A well-tested explicit finite-difference method (FDM) which is forward in time and central in space is employed for the solution of a nonlinear initial boundary value problem corresponding to each region. Validation of the FDM computations is achieved with a variational finite element method algorithm. The influences of the emerging geometric and rheological parameters on axial velocity, resistance impedance and wall shear stress are displayed graphically. The instantaneous patterns of streamlines are also presented to illustrate the global behaviour of the blood flow. The simulations are relevant to haemodynamics of small blood vessels and capillary transport, wherein rheological effects are dominant.
Cholera is an important public health problem in Bangladesh. Interventions to prevent cholera depend on their cost-effectiveness which in turn depends on cholera incidence. Hospital-based diarrhoeal disease surveillance has been ongoing in six Bangladeshi hospitals where a systematic proportion of patients admitted with diarrhoea were enrolled and tested for Vibrio cholerae. However, incidence calculation using only hospital data underestimates the real disease burden because many ill persons seek treatment elsewhere. We conducted a healthcare utilization survey in the catchment areas of surveillance hospitals to estimate the proportion of severe diarrhoeal cases that were admitted to surveillance hospitals and estimated the population-based incidence of severe diarrhoea due to V. cholerae by combining both hospital surveillance and catchment area survey data. The estimated incidence of severe diarrhoea due to cholera ranged from 0·3 to 4·9/1000 population in the catchment area of surveillance hospitals. In children aged <5 years, incidence ranged from 1·0 to 11·0/1000 children. Diarrhoeal deaths were most common in the Chhatak Hospital's catchment area (18·5/100 000 population). This study provides a credible estimate of the incidence of severe diarrhoea due to cholera in Bangladesh, which can be used to assess the cost-effectiveness of cholera prevention activities.
The interaction between an 8:1 aspect ratio rectangular jet and a flat plate, placed parallel to the jet, is addressed in this study. At high subsonic conditions and for certain relative locations of the plate, a resonance takes place with accompanying audible tones. Even when the tone is not audible the sound pressure level spectra are often marked by conspicuous peaks. The frequencies of these peaks, as functions of the plate’s length, its location relative to the jet as well as jet Mach number, are studied in an effort to understand the flow mechanism. It is demonstrated that the tones are not due to a simple feedback between the nozzle exit and the plate’s trailing edge; the leading edge also comes into play in determining the frequency. With parametric variation, it is found that there is an order in the most energetic spectral peaks; their frequencies cluster in distinct bands. The lowest frequency band is explained by an acoustic feedback involving diffraction at the plate’s leading edge. Under the resonant condition, a periodic flapping motion of the jet column is seen when viewed in a direction parallel to the plate. Phase-averaged Mach number data on a cross-stream plane near the plate’s trailing edge illustrate that the jet cross-section goes through large contortions within the period of the tone. Farther downstream a clear ‘axis switching’ takes place for the time-averaged cross-section of the jet that does not occur otherwise for a non-resonant condition.
This study aimed to determine the prevalence of hearing impairment in Bangladeshi people of all ages.
A nationally representative cross-sectional survey was carried out in 2013. A total of 4260 subjects (1774 males and 2486 females), with a mean age of 32 years, participated. Hearing impairment was determined by pure tone audiometry and otoacoustic emissions testing.
Disabling hearing loss (greater than 40 dB loss in adults, and greater than 30 dB loss in children younger than 15 years, in their better hearing ears) was present in 9.6 per cent (95 per cent confidence interval, 8.5–10.8 per cent) of the respondents. Hearing loss was more prevalent in socio-economically deprived people and in those older than 60 years. Multiple logistic regression analysis identified age, socio-economic deprivation, family history, impacted ear wax, chronic suppurative otitis media, otitis media with effusion, and otitis externa as the significant predictors of disabling hearing loss.
Deafness prevention should focus mainly on chronic suppurative otitis media, otitis media with effusion, and impacted ear wax prevention, integrated within the primary healthcare system and addressing the equity issue.
The cropping systems of the Eastern Gangetic Plains of Bangladesh, India and Nepal are based on rice. There is a scope to intensify such systems through diversification with lentil, the most popular food legume. Two strategies were evaluated to fit lentil into the short fallow between successive monsoonal (i.e., T. aman) and pre-monsoonal (aus) or irrigated rice (boro) crop. These were early-flowering sole-cropped lentil and relay-sown lentil into rice. Firstly, 18 early-flowering lentil lines at three contrasting sowing dates were tested over two seasons on a research station at Ishurdi in Bangladesh. Secondly, relay sowing was evaluated at the same location with six early-flowering lines and two control cultivars in two seasons. It was also assessed on ten farms in Western Bangladesh, comparing relay with sole cropping over 3 years. Flowering in the early-flowering lentil lines was consistently 9–17 days earlier, than the control cultivars, but they did not achieve an economic yield (<1·0 t/ha). Relay sowing with an existing cultivar produced an economic yield of lentil, which was comparable or higher than sole-cropped lentil in all situations. The relay-sown lentil matured in sufficient time to allow the land to be prepared for the succeeding rain-fed rice crop. It was concluded that the substitution of relay-sown lentil for fallow in the monsoonal rice–fallow–rain-fed rice cropping pattern is a useful option to intensify and diversify cropping in the Eastern Gangetic Plain.
Presence of Vibrio cholerae serogroups O1 and O139 in the waters of the rural area of Matlab, Bangladesh, was investigated with quantitative measurements performed with a portable flow cytometer. The relevance of this work relates to the testing of a field-adapted measurement protocol that might prove useful for cholera epidemic surveillance and for validation of mathematical models. Water samples were collected from different water bodies that constitute the hydrological system of the region, a well-known endemic area for cholera. Water was retrieved from ponds, river waters, and irrigation canals during an inter-epidemic time period. Each sample was filtered and analysed with a flow cytometer for a fast determination of V. cholerae cells contained in those environments. More specifically, samples were treated with O1- and O139-specific antibodies, which allowed precise flow-cytometry-based concentration measurements. Both serogroups were present in the environmental waters with a consistent dominance of V. cholerae O1. These results extend earlier studies where V. cholerae O1 and O139 were mostly detected during times of cholera epidemics using standard culturing techniques. Furthermore, our results confirm that an important fraction of the ponds’ host populations of V. cholerae are able to self-sustain even when cholera cases are scarce. Those contaminated ponds may constitute a natural reservoir for cholera endemicity in the Matlab region. Correlations of V. cholerae concentrations with environmental factors and the spatial distribution of V. cholerae populations are also discussed.
We investigated whether straight-line distance from residential compounds to healthcare facilities influenced mortality, the incidence of pneumonia and vaccine efficacy against pneumonia in rural Gambia. Clinical surveillance for pneumonia was conducted on 6938 children living in the catchment areas of the two largest healthcare facilities. Deaths were monitored by three-monthly home visits. Children living >5 km from the two largest healthcare facilities had a 2·78 [95% confidence interval (CI) 1·74–4·43] times higher risk of all-cause mortality compared to children living within 2 km of these facilities. The observed rate of clinical and radiological pneumonia was lower in children living >5 km from these facilities compared to those living within 2 km [rate ratios 0·65 (95% CI 0·57–0·73) and 0·74 (95% CI 0·55–0·98), respectively]. There was no association between distance and estimated pneumococcal vaccine efficacy. Geographical access to healthcare services is an important determinant of survival and pneumonia in children in rural Gambia.
Roselle (Hibiscus sabdariffa L.) is an economically important plant in Niger. Little is known about its genetic diversity and population structure. In this study, we performed the first diversity assessment of a collection of 124 roselle accessions and 16 accessions of its close relatives Hibiscuscannabinus and Abelmoschusesculentus. Our study was based on ten agromorphological traits and 267 amplified fragment length polymorphism markers. We identified two major distinct groups in H. sabdariffa using a Bayesian method. These two genetic groups were associated with statistical differences for three phenological characteristics: number of days to flowering, 100-seed weight and calyx size. However, the calyx colour, i.e. a morphological characteristic often used to classify different local ecotypes, did not superimpose this separation. Our findings suggested that roselle diversity is genetically structured; the two different groups were clearly associated with morphological differences but were not commonly used by farmers for their classification. The impact of the perceived ecotype structure and its consequence on farmer management is discussed.
The aim of this study was to determine the nationwide prevalence of smear-positive tuberculosis (TB) in Bangladesh. A multi-stage cluster survey of a random sample of persons aged ⩾15 years was included in 40 clusters (20 urban, 20 rural). Two sputum samples were collected from study participants and tested initially by fluorescence microscopy and confirmed by the Ziehl–Neelsen method. The crude and adjusted prevalence rates and 95% confidence intervals (CIs) were calculated using standard methods. A total of 33 new smear-positive TB cases were detected among 52 098 individuals who participated in the study. The average participation rate was over 80%. The overall crude prevalence of new smear-positive TB in persons aged ⩾15 years was estimated as 63·3/100 000 (95% CI 43·6–88·9) and the adjusted prevalence was 79·4/100 000 (95% CI 47·1–133·8). TB prevalence was higher in males (n=24) and in rural areas (n=20). The prevalence was highest in the 55–64 years age group (201/100 000) and lowest in 15–24 years age group (43·0/100 000). The prevalence was higher in persons with no education (138·6/100 000, 95% CI 78·4–245·0). The overall prevalence of smear-positive TB was significantly lower than the prevalence estimate of the previous nationwide survey in Bangladesh in 1987–1988 (870/100 000).
In this study, the stress-deformation response of coal in the laboratory under threedimensional (3-D) loading conditions similar to those existing in an actual coal mine is investigated, and a constitutive model, including the effects of anisotropy, is developed. The coal samples were obtained from a mine in LeFlore County, Oklahoma, at a depth of approximately 25–30 ft below the ground surface. A High Capacity Cubical Device with servo-controlled independent loading along three axes of a cubical specimen and a computerized data acquisition and monitoring system were used to conduct the tests. A total of 21 tests under 4 different confining pressures and 5 different stress paths were conducted. The influence of the degree of anisotropy was investigated by comparing the transversely isotropic and isotropic idealizations for different stress paths (Triaxial Compression, Triaxial Extension and Simple Shear) at different confining pressures (1,600, 3,200 and 5,600 psi). The experimental results demonstrated that the coal exhibits inherent anisotropy and that it can be treated approximately as a transversely isotropic material. Also, the Young's moduli were found to be dependent on the confining pressure. The experimental data were used to evaluate the material constants associated with the elasto-plastic constitutive model developed in the study.
In this paper we present a comprehensive study of the impact of the Hydrogen (H2) annealing conditions on nano scale silicon fin structures. Hydrogen pressure was varied from 15Torr to 600Torr and anneal temperature was varied from 600°C to 900°C. We found H2 annealing can cause faceting, corner rounding and smoothing of the etched silicon surfaces. The degree of the fin transformation is a function of both pressure and temperature. Furthermore, low pressure and high temperature enhance the silicon movement and can cause damage to the nano scale fins.
Our understanding of anatomical differences in people with autistic-spectrum disorder, is based on mixed-gender or male samples.
To study regional grey-matter and white-matter differences in the brains of women with autistic-spectrum disorder.
We compared the brain anatomy of 14 adult women with autistic-spectrum disorder with 19 controls using volumetric magnetic resonance imaging and voxel-based morphometry Results Women with autistic-spectrum disorder had a smaller density bilaterally of grey matter in the frontotemporal cortices and limbic system, and of white matter in the temporal lobes (anterior) and pons. In contrast, they had a larger white-matter density bilaterally in regions of the association and projection fibres of the frontal, parietal, posterior temporal and occipital lobes, in the commissural fibres of the corpus callosum (splenium) and cerebellum (anterior lobe). Further, we found a negative relationship between reduced grey-matter density in right limbic regions and social communication ability.
Women with autistic-spectrum disorder have significant differences in brain anatomy from controls, in brain regions previously reported as abnormal in adult men with the disorder. Some anatomical differences may be related to clinical symptoms.
We conducted a seroprevalence study and exposure survey of healthcare workers to assess the risk of nosocomial transmission of Nipah virus during an outbreak in Bangladesh in 2004. No evidence of recent Nipah virus infection was detected despite substantial exposures and minimal use of personal protective equipment.
Osmotic constraints, nutrient deficiencies, especially phosphorus, and the lack of efficient strains of rhizobia in Mediterranean soils are major factors limiting symbiotic nitrogen fixation and yield in common bean (Phaseolus vulgaris). In order to improve yields, we investigated responses to rhizobial inoculation and P fertilization under glasshouse and field conditions with two bean cultivars, Coco blanc and BAT477. The nodulation test, using a hydroponic system in a glasshouse, revealed strong variability among 22 rhizobium strains of various origins, in their symbiotic efficiency, compared with Rhizobium tropici CIAT899. The introduced strains proved to be more efficient although some local rhizobia revealed high potential efficiencies. Glasshouse trials showed a significant effect of inoculation and P supply on nodulation, N content and shoot dry weight that varied with rhizobial strain. Field trials substantiated the glasshouse observations and emphasized the effects of cultivar-rhizobia interactions on symbiotic parameters and yields. It is concluded that inoculation with suitable rhizobia with supply of additional P is a technology that may improve symbiotic nitrogen fixation and yield in common bean in some soils under a Mediterranean climate.
The objective of the study was to determine the prevalence of smear-positive tuberculosis (TB) in a rural area in Bangladesh at Matlab. A TB surveillance system was established among 106000 people in rural Bangladesh at Matlab. Trained field workers interviewed all persons aged [ges ]15 years to detect suspected cases of TB (cough>21 days) and sputum specimens of suspected cases were examined for acid-fast bacilli (AFB). Of 59395 persons interviewed, 4235 (7·1%) had a cough for >21 days. Sputum specimens were examined for AFB from 3834 persons, 52 (1·4%) of them were positive for AFB. The prevalence of chronic cough and sputum positivity were significantly higher among males compared to females (P<0·001). The population-based prevalence rate of smear-positive TB cases was 95/100000 among persons aged [ges ]15 years. Cases of TB clustered geographically (relative risk 5·53, 95% CI 3·19–9·59). The high burden of TB among rural population warrants appropriate measures to control TB in Bangladesh. The higher prevalence of persistent cough and AFB-positive sputum among males need further exploration. Factors responsible for higher prevalence of TB in clusters should be investigated.