Evaluation of improved and local/landrace/sorghum varieties for covered kernel smut

Twelve varieties of improved and local (landrace) sorghum were tested under artificial inoculation conditions. Out of 12 sorghum varieties evaluated with covered kernel smut, notably local cultivar ‘Tetron’ was found to be highly resistant. Disease incidence and severity on the rest of the cultivars varied from 21 to 47% and 40 to 53% respectively. Differences among cultivars in yield loss were also observed. The highest yield loss (40%) was recorded on 97 MW 6129 (NVT-11 4) and for Tetron yield loss was nil. The effect of disease on germination was noticed but cannot be considered as conclusive due to moisture stress at the time of germination.     

The prion protein binds thiamine

Although highly conserved throughout evolution, the exact biological function of the prion protein is still unclear. In an effort to identify the potential biological functions of the prion protein we conducted a small-molecule screening assay using the Syrian hamster prion protein [shPrP(90-232)]. The screen was performed using a library of 149 water-soluble metabolites that are known to pass through the blood-brain barrier. Using a combination of 1D NMR, fluorescence quenching and surface plasmon resonance we identified thiamine (vitamin B1) as a specific prion ligand with a binding constant of ~60 μM. Subsequent studies showed that this interaction is evolutionarily conserved, with similar binding constants being seen for mouse, hamster and human prions. Various protein construct lengths, both with and without the unstructured N-terminal region in the presence and absence of copper, were examined. This indicates that the N-terminus has no influence on the protein's ability to interact with thiamine. In addition to thiamine, the more biologically abundant forms of vitamin B1 (thiamine monophosphate and thiamine diphosphate) were also found to bind the prion protein with similar affinity. Heteronuclear NMR experiments were used to determine thiamine's interaction site, which is located between helix 1 and the preceding loop. These data, in conjunction with computer-aided docking and molecular dynamics, were used to model the thiamine-binding pharmacophore and a comparison with other thiamine binding proteins was performed to reveal the common features of interaction.     

A plant cell division algorithm based on cell biomechanics and ellipse-fitting

Background and Aims

The importance of cell division models in cellular pattern studies has been acknowledged since the 19th century. Most of the available models developed to date are limited to symmetric cell division with isotropic growth. Often, the actual growth of the cell wall is either not considered or is updated intermittently on a separate time scale to the mechanics. This study presents a generic algorithm that accounts for both symmetrically and asymmetrically dividing cells with isotropic and anisotropic growth. Actual growth of the cell wall is simulated simultaneously with the mechanics.

Methods

The cell is considered as a closed, thin-walled structure, maintained in tension by turgor pressure. The cell walls are represented as linear elastic elements that obey Hooke''s law. Cell expansion is induced by turgor pressure acting on the yielding cell-wall material. A system of differential equations for the positions and velocities of the cell vertices as well as for the actual growth of the cell wall is established. Readiness to divide is determined based on cell size. An ellipse-fitting algorithm is used to determine the position and orientation of the dividing wall. The cell vertices, walls and cell connectivity are then updated and cell expansion resumes. Comparisons are made with experimental data from the literature.

Key Results

The generic plant cell division algorithm has been implemented successfully. It can handle both symmetrically and asymmetrically dividing cells coupled with isotropic and anisotropic growth modes. Development of the algorithm highlighted the importance of ellipse-fitting to produce randomness (biological variability) even in symmetrically dividing cells. Unlike previous models, a differential equation is formulated for the resting length of the cell wall to simulate actual biological growth and is solved simultaneously with the position and velocity of the vertices.

Conclusions

The algorithm presented can produce different tissues varying in topological and geometrical properties. This flexibility to produce different tissue types gives the model great potential for use in investigations of plant cell division and growth in silico.     

The Quality of Sputum Smear Microscopy in Public-Private Mix Directly Observed Treatment Laboratories in West Amhara Region,Ethiopia

Ethiopia adopted Public-Private Mix Directly Observed Treatment Short Course Chemotherapy (PPM-DOTS) strategy for tuberculosis (TB) control program. Quality of sputum smear microscopy has paramount importance for tuberculosis control program in resource-poor countries like Ethiopia. A cross-sectional study was conducted to assess the quality of sputum smear microscopy in 37 Public-Private Mix laboratories in West Amhara, Ethiopia. The three external quality assessment methods (onsite evaluation, panel testing and blind rechecking) were employed. Onsite assessment revealed that 67.6% of PPM-DOTS laboratories were below the standard physical space (5 X 6) m². The average monthly workload per laboratory technician was 19.5 (SD±2.9) slides with 12.8% positivity rate. The quality of Acid Fast Bacilli (AFB) staining reagents was sub-standard. The overall agreement for blind rechecking of 1,123 AFB slides was 99.4% (Kappa = 0.97). Reading of 370 AFB panel slides showed 3.5% false reading (Kappa = 0.92). Moreover, the consistency of reading scanty bacilli slides was lower (93%) compared to 1+, 2+ and 3+ bacilli. Based on blind rechecking and panel testing results, PPM-DOTS site laboratories showed good agreement with the reference laboratory. Physical space and qualities of AFB reagents would be areas of intervention to sustain the quality of sputum smear microscopy. Therefore, regular external quality assessment and provision of basic laboratory supplies for TB diagnosis would be the way forward to improve the quality of sputum smear microscopy services in PPM-DOTS laboratories.     

Men Traveling Away from Home Are More Likely to Bring Malaria into High Altitude Villages,Northwest Ethiopia

Background

Information about malaria risk factors at high altitudes is scanty. Understanding the risk factors that determine the risk of malaria transmission at high altitude villages is important to facilitate implementing sustainable malaria control and prevention programs.

Methods

An unmatched case control study was conducted among patients seeking treatment at health centers in high altitude areas. Either microscopy or rapid diagnostic tests were used to confirm the presence of plasmodium species. A generalized linear model was used to identify the predictors of malaria transmission in high altitude villages.

Results

Males (AOR = 3.11, 95%CI: 2.28, 4.23), and those who traveled away from the home in the previous month (AOR = 2.01, 95% CI: 1.56, 2.58) were strongly associated with presence of malaria in high altitude villages. Other significant factors, including agriculture in occupation (AOR = 1.41, 95% CI: 1.05, 1.93), plants used for fencing (AOR = 1.70, 95% CI: 1.18, 2.52) and forests near the house (AOR = 1.60, 95% CI: 1.15, 2.47), were found predictors for malaria in high altitude villages.

Conclusion

Travel outside of their home was an important risk of malaria infections acquisition. Targeting males who frequently travel to malarious areas can reduce malaria transmission risks in high altitude areas.     

Status of chickpea fusarium wilt (Fusarium oxysporum f.sp. ciceris) in northwestern Ethiopia

Surveys for incidence of fusarium wilt of chickpea were carried out in six districts of North and South Gondar, and East Gojam administrative zones, Amhara National Regional State in northwestern Ethiopia in 2006–2007 and 2007–2008 main cropping seasons. In each district, five representative peasant administrations (PAs) were selected based mainly on chickpea-growing area coverage, and, in each PA, disease was assessed in five randomly selected farmers’ fields. In the two cropping seasons, the mean incidences recorded in each district were as follows: Gondar Zuria, 34.16% and 34.11%; Dembia, 37.90% and 35.36%; Libo-Kemkem, 34.74% and 28.81%; Fogera, 34.74% and 28.81%; Dejen, 34.74% and 28.81% and Enemay, 33.34% and 37.64%. The result indicated that fusarium wilt is currently highly distributed in all surveyed chickpea-growing areas of northwestern part of Ethiopia. Therefore, possible management options are vital to alleviate the problem.     

Causes of Death among Adults in Northern Ethiopia: Evidence from Verbal Autopsy Data in Health and Demographic Surveillance System

Background

In countries where registration of vital events is lacking and the proportion of people who die at home without medical care is high, verbal autopsy is used to determine and estimate causes of death.

Methods

We conducted 723 verbal autopsy interviews of adult (15 years of age and above) deaths from September 2009 to January 2013. Trained physicians interpreted the collected verbal autopsy data, and assigned causes of death according to the international classification of diseases (ICD-10). We did analysis of specific as well as broad causes of death (i.e. non-communicable diseases, communicable diseases and external causes of death) by sex and age using Stata version 11.1. We performed logistic regression to identify socio-demographic predictors using odds ratio with 95% confidence interval and a p-value of 0.05.

Findings

Tuberculosis, cerebrovascular diseases and accidental falls were leading specific causes of death accounting for 15.9%, 7.3% and 3.9% of all deaths. Two hundred sixty three (36.4% [95% CI: 32.9, 39.9]), 252 (34.9% [95% CI: 31.4, 38.4]) and 89 (12.3% [95% CI: 10.1, 14.9]) deaths were due to non-communicable, communicable diseases, and external causes, respectively. Females had 1.5 times (AOR = 1.53 [95% CI: 1.10, 2.15]) higher odds of dying due to communicable diseases than males. The odds of dying due to external causes were 4 times higher among 15–49 years of age (AOR = 4.02 [95% CI: 2.25, 7.18]) compared to older ages. Males also had 1.7 times (AOR = 1.70 [95% CI: 1.01, 2.85]) higher odds of dying due to external causes than females.

Conclusion

Tuberculosis, cerebrovascular diseases and accidental falls were the top three causes of death among adults. Efforts to prevent tuberculosis and cerebrovascular diseases related deaths should be improved and safety efforts to reduce accidents should also receive attention.     

Post-Operative Recurrent Trachomatous Trichiasis Is Associated with Increased Conjunctival Expression of S100A7 (Psoriasin)

Background

Surgery for trachomatous trichiasis (TT) is a key component of the SAFE Strategy for trachoma control. Unfortunately, recurrent TT following surgery is common, probably due to various surgical and disease factors. To develop strategies to reduce recurrence rates it is necessary to understand its pathological basis. In this study we investigated the relationship between recurrent trichiasis and the expression of various cytokines and fibrogenic genes during a two-year follow-up period.

Methodology/Principal Findings

Individuals undergoing surgery for TT were examined at baseline (pre-operative), 6, 12, 18 and 24 months. Conjunctival swab samples were collected from the tarsal conjunctiva for RNA isolation on each occasion. Individuals who developed recurrent TT with at least 3 lashes touching the eye on one or more occasion were designated “cases” and an equal number of “controls” were randomly selected from those without recurrent TT, frequency matched for age and baseline TT severity. The expression of the following genes was measured by quantitative RT-PCR: S100A7, IL1B, CXCL5, TNFA, NOS2A, CTGF, MMP7, MMP9 and MMP12. Thirteen hundred individuals were enrolled and underwent surgery. By two years 122 had developed recurrent TT with at least 3 lashes touching the eye. Recurrent TT was consistently associated across multiple time points with about a 2-fold increase in S100A7 expression (p = 0.008). Clinically visible conjunctival inflammation was associated with increased S100A7, IL1B, CXCL5, MMP9 and MMP12 expression.

Conclusions/Significance

Increased S100A7 expression was associated with trachomatous conjunctival scarring and may be linked to the pathophysiology of recurrent TT. S100A7 expression could be a potential biomarker for this disease process. As part of the epithelial innate immune response S100A7 has multiple actions, potentially contributing to a chronic pro-inflammatory response, which may lead to ongoing tissue damage and increased scarring.