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21.
Bongani Petros Kubheka Mark Delmege Laing Kwasi Sackey Yobo 《Archives Of Phytopathology And Plant Protection》2013,46(7-8):373-386
AbstractA study was conducted over two seasons in a marginal soil with an acid saturation of 54%. A plant growth promoting rhizobacterium, Bacillus megaterium, a commercial biocontrol agent, Trichoderma harzianum Strain kd (Eco-T®), and soluble potassium silicate were used in this study. The objective was to control maize yield reduction caused by Rhizoctonia solani AG2 root rot isolated from infected maize. R. solani reduced maize yields significantly by 34% in the first season. However, the losses decreased in the second season from 34% to 10%. In the first season, combination of T. harzianum, B. megaterium and potassium silicate increased maize yields by 130%. The highest yield in the presence of R. solani was treatments with T. harzianum (216%) followed by T. harzianum plus potassium silicate (214%) and lastly T. harzianum plus B. megaterium (178%). However, in the second season, T. harzianum plus potassium silicate treatment resulted in the highest yields. 相似文献
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Current international interest in finding alternative sources of energy to the diminishing supplies of fossil fuels has encouraged research efforts in improving biofuel production technologies. In countries which lack sufficient food, the use of sustainable lignocellulosic feedstocks, for the production of bioethanol, is an attractive option. In the pre-treatment of lignocellulosic feedstocks for ethanol production, various chemicals and/or enzymatic processes are employed. These methods generally result in a range of fermentable sugars, which are subjected to microbial fermentation and distillation to produce bioethanol. However, these methods also produce compounds that are inhibitory to the microbial fermentation process. These compounds include products of sugar dehydration and lignin depolymerisation, such as organic acids, derivatised furaldehydes and phenolic acids. These compounds are known to have a severe negative impact on the ethanologenic microorganisms involved in the fermentation process by compromising the integrity of their cell membranes, inhibiting essential enzymes and negatively interact with their DNA/RNA. It is therefore important to understand the molecular mechanisms of these inhibitions, and the mechanisms by which these microorganisms show increased adaptation to such inhibitors. Presented here is a concise overview of the molecular adaptation mechanisms of ethanologenic bacteria in response to lignocellulose-derived inhibitory compounds. These include general stress response and tolerance mechanisms, which are typically those that maintain intracellular pH homeostasis and cell membrane integrity, activation/regulation of global stress responses and inhibitor substrate-specific degradation pathways. We anticipate that understanding these adaptation responses will be essential in the design of ''intelligent'' metabolic engineering strategies for the generation of hyper-tolerant fermentation bacteria strains. 相似文献
23.
Sorghum bicolor, a drought tolerant cereal crop, is not only an important food source in the semi arid/arid regions but also a potential model for studying and gaining a better understanding of the molecular mechanisms of drought and salt stress tolerance in cereals. In this study, seeds of a sweet sorghum variety, MN1618, were planted and grown on solid MS growth medium with or without 100mM NaCl. Heat shock protein expression immunoblotting assays demonstrated that this salt treatment induced stress within natural physiological parameters for our experimental material. 2D PAGE in combination with MS/MS proteomics techniques were used to separate, visualise and identify salinity stress responsive proteins in young sorghum leaves. Out of 281 Coomassie stainable spots, 118 showed statistically significant responses (p<0.05) to salt stress treatments. Of the 118 spots, 79 were selected for tandem mass spectrometric identification, owing to their good resolution and abundance levels, and of these, 55 were positively identified. Identified proteins were divided into six functional categories including both known and novel/putative stress responsive proteins. Molecular and physiological functions of some of our proteins of interest are currently under investigation via bioinformatic and molecular biology approaches. 相似文献
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Ntobeko B. A. Ntusi Motasim Badri Freedom Gumedze Karen Sliwa Bongani M. Mayosi 《PloS one》2015,10(8)
Aims
There is controversy regarding the inclusion of patients with hypertension among cases of peripartum cardiomyopathy (PPCM), as the practice has contributed significantly to the discrepancy in reported characteristics of PPCM. We sought to determine whether hypertensive heart failure of pregnancy (HHFP) (i.e., peripartum cardiac failure associated with any form of hypertension) and PPCM have similar or different clinical features and outcome.Methods and Results
We compared the time of onset of symptoms, clinical profile (including electrocardiographic [ECG] and echocardiographic features) and outcome of patients with HHFP (n = 53; age 29.6 ± 6.6 years) and PPCM (n = 30; age 31.5 ± 7.5 years). The onset of symptoms was postpartum in all PPCM patients, whereas it was antepartum in 85% of HHFP cases (p<0.001). PPCM was more significantly associated with the following features than HHFP (p<0.05): twin pregnancy, smoking, cardiomegaly with lower left ventricular ejection fraction on echocardiography, and longer QRS duration, QRS abnormalities, left atrial hypertrophy, left bundle branch block, T wave inversion and atrial fibrillation on ECG. By contrast, HHFP patients were significantly more likely (p<0.05) to have a family history of hypertension, hypertension and pre-eclampsia in a previous pregnancy, tachycardia at presentation on ECG, and left ventricular hypertrophy on echocardiography. Chronic heart failure, intra-cardiac thrombus and pulmonary hypertension were found significantly more commonly in PPCM than in HHFP (p<0.05). There were 5 deaths in the PPCM group compared to none among HHFP cases (p = 0.005) during follow-up.Conclusion
There are significant differences in the time of onset of heart failure, clinical, ECG and echocardiographic features, and outcome of HHFP compared to PPCM, indicating that the presence of hypertension in pregnancy-associated heart failure may not fit the case definition of idiopathic PPCM. 相似文献27.
Satish Gopal Yuri Fedoriw Bongani Kaimila Nathan D. Montgomery Edwards Kasonkanji Agnes Moses Richard Nyasosela Suzgo Mzumara Carlos Varela Maria Chikasema Victor Makwakwa Salama Itimu Tamiwe Tomoka Steve Kamiza Bal M. Dhungel Fred Chimzimu Coxcilly Kampani Robert Krysiak Kristy L. Richards Thomas C. Shea N. George Liomba 《PloS one》2016,11(3)
There are no prospective studies of aggressive non-Hodgkin lymphoma (NHL) treated with CHOP in sub-Saharan Africa. We enrolled adults with aggressive NHL in Malawi between June 2013 and May 2015. Chemotherapy and supportive care were standardized, and HIV+ patients received antiretroviral therapy (ART). Thirty-seven of 58 patients (64%) were HIV+. Median age was 47 years (IQR 39–56), and 35 (60%) were male. Thirty-five patients (60%) had stage III/IV, 43 (74%) B symptoms, and 28 (48%) performance status ≥2. B-cell NHL predominated among HIV+ patients, and all T-cell NHL occurred among HIV- individuals. Thirty-one HIV+ patients (84%) were on ART for a median 9.9 months (IQR 1.1–31.7) before NHL diagnosis, median CD4 was 121 cells/μL (IQR 61–244), and 43% had suppressed HIV RNA. HIV+ patients received a similar number of CHOP cycles compared to HIV- patients, but more frequently developed grade 3/4 neutropenia (84% vs 31%, p = 0.001), resulting in modestly lower cyclophosphamide and doxorubicin doses with longer intervals between cycles. Twelve-month overall survival (OS) was 45% (95% CI 31–57%). T-cell NHL (HR 3.90, p = 0.017), hemoglobin (HR 0.82 per g/dL, p = 0.017), albumin (HR 0.57 per g/dL, p = 0.019), and IPI (HR 2.02 per unit, p<0.001) were associated with mortality. HIV was not associated with mortality, and findings were similar among patients with diffuse large B-cell lymphoma. Twenty-three deaths were from NHL (12 HIV+, 11 HIV-), and 12 from CHOP (9 HIV+, 3 HIV-). CHOP can be safe, effective, and feasible for aggressive NHL in Malawi with and without HIV. 相似文献
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We conducted herbaceous and woody vegetation surveys across Botswana's southern Okavango Buffalo Fence, which separates wildlife management from tribal grazing areas, to determine whether the restriction of herbivore movement by fencing has influenced vegetation composition, diversity and structure. We sampled herbaceous and woody vegetation at twenty paired sites every 2 km along the fence. For the herbaceous layer, ten 0.25 m2 quadrats were laid every 10 m perpendicular to the fence; while for the woody vegetation, variable quadrat plots were used. Paired t‐tests were run. Results show little difference in forb or grass composition between the two sides. However, the cover and diversity of many woody species were greatly reduced across most height classes on the wildlife management side. Overall woody cover on the wildlife side of the fence was nearly half that of the tribal grazing side (t = 2.83, P = 0.011, df = 19), while overall wood diversity was also significantly less on the wildlife side (t = 3.29, P = 0.004, df = 19). We conclude that the concentration of wildlife due to the fence, while improving habitat for some herbivore species, is having a detrimental effect on plant diversity in general. 相似文献
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Yamikani Mastala Phempo Nyangulu Rodrick V. Banda Bongani Mhemedi Sarah A. White Theresa J. Allain 《PloS one》2013,8(3)
Objectives
To determine the prevalence of vitamin D deficiency (VDD) in adult medical, non-tuberculous (non-TB) patients. To investigate associations with VDD. To compare the results with a similar study in TB patients at the same hospital.Design
Cross-sectional sample.Setting
Central hospital in Malawi.Participants
Adult non-TB patients (n = 157), inpatients and outpatients.Outcome Measures
The primary outcome was the prevalence of VDD. Potentially causal associations sought included nutritional status, in/outpatient status, HIV status, anti-retroviral therapy (ART) and, by comparison with a previous study, a diagnosis of tuberculosis (TB).Results
Hypovitaminosis D (≤75 nmol/L) occurred in 47.8% (75/157) of patients, 16.6% (26/157) of whom had VDD (≤50 nmol/L). None had severe VDD (≤25 nmol/L). VDD was found in 22.8% (23/101) of in-patients and 5.4% (3/56) of out-patients. In univariable analysis in-patient status, ART use and low dietary vitamin D were significant predictors of VDD. VDD was less prevalent than in previously studied TB patients in the same hospital (68/161 = 42%). In multivariate analysis of the combined data set from both studies, having TB (OR 3.61, 95%CI 2.02–6.43) and being an in-patient (OR 2.70, 95%CI 1.46–5.01) were significant independent predictors of VDD.Conclusions
About half of adult medical patients without TB have suboptimal vitamin D status, which is more common in in-patients. VDD is much more common in TB patients than non-TB patients, even when other variables are controlled for, suggesting that vitamin D deficiency is associated with TB. 相似文献30.
Carolina E Lemmer Mark E Engel John C Stanfliet Bongani M Mayosi 《Cardiovascular ultrasound》2014,12(1):1-17