95 research outputs found

    Isolation of cowpea genes conferring drought tolerance: Construction of a cDNA drought expression library

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    The main objective of this study was to identify and isolate the genes conferring drought tolerance in cowpea. A cDNA library enriched for cowpea genes expressed specifically during responses to drought was constructed. A procedure called suppression subtractive hybridisation (SSH) was successfully employed to obtain these differentially expressed transcripts. The library consists of 4 160 individual clones. Preliminary sequencing results identified two clones to be known stress-related plant genes (GST (glutathione-S-transferase) and PR-1 (pathogenesis-related protein-1)). Micro-array analysis will be performed on the library’s clones to verify their differential expression during drought conditions, and to identify additional clones for further investigation. Promising genes can eventually be used to genetically engineer crops for drought tolerance to improve food security in water-stressed areas.Keywords: cowpea, drought tolerance, suppression subtractive hybridisation (SSH

    Isolation of cowpea genes conferring drought tolerance: Construction of a cDNA drought expression library#

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    The main objective of this study was to identify and isolate the genes conferring drought tolerance in cowpea. A cDNA library enriched for cowpea genes expressed specifically during responses to drought was constructed. A procedure called suppression subtractive hybridisation (SSH) was successfully employed to obtain these differentially expressed transcripts.The library consists of 4 160 individual clones. Preliminary sequencing results identified two clones to be known stress-related plant genes (GST (glutathione-S-transferase) and PR-1 (pathogenesis-related protein-1)). Micro-array analysis will be performed on the library’s clones to verify their differential expression during drought conditions, and to identify additional clones for further investigation. Promising genes can eventually be used to genetically engineer crops for drought tolerance to improve food security in water-stressed areas

    Audits of oncology units – an effective and pragmatic approach

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    CITATION: Abratt, R. P., et al. 2017. Audits of oncology units – an effective and pragmatic approach. South African Medical Journal, 107(6):493-496, doi:10.7196/SAMJ.2017.v107i6.12356.The original publication is available at http://www.samj.org.za/index.php/samjBackground. Audits of oncology units are part of all quality-assurance programmes. However, they do not always come across as pragmatic and helpful to staff. Objective. To report on the results of an online survey on the usefulness and impact of an audit process for oncology units. Methods. Staff in oncology units who were part of the audit process completed the audit self-assessment form for the unit. This was followed by a visit to each unit by an assessor, and then subsequent personal contact, usually via telephone. The audit self-assessment document listed quality-assurance measures or items in the physical and functional areas of the oncology unit. There were a total of 153 items included in the audit. The online survey took place in October 2016. The invitation to participate was sent to 59 oncology units at which staff members had completed the audit process. Results. The online survey was completed by 54 (41%) of the 132 potential respondents. The online survey found that the audit was very or extremely useful in maintaining personal professional standards in 89% of responses. The audit process and feedback was rated as very or extremely satisfactory in 80% and 81%, respectively. The self-assessment audit document was scored by survey respondents as very or extremely practical in 63% of responses. The feedback on the audit was that it was very or extremely helpful in formulating improvement plans in oncology units in 82% of responses. Major and minor changes that occurred as a result of the audit process were reported as 8% and 88%, respectively. Conclusion. The survey findings show that the audit process and its self- assessment document meet the aims of being helpful and pragmatic.http://www.samj.org.za/index.php/samj/article/view/11919Publisher's versio

    Pretomanid with bedaquiline and linezolid for drug-resistant TB: a comparison of prospective cohorts

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    BACKGROUND: There are no data comparing the 6-9 month oral three-drug Nix regimen (bedaquiline, pretomanid and linezolid [BPaL]) to conventional regimens containing bedaquiline (B, BDQ) and linezolid (L, LZD).METHODS: Six-month post end-of-treatment outcomes were compared between Nix-TB (n = 109) and 102 prospectively recruited extensively drug-resistant TB patients who received an ˜18-month BDQ-based regimen (median of 8 drugs). A subset of patients received BDQ and LZD (n = 86), and a subgroup of these (n = 75) served as individually matched controls in a pairwise comparison to determine differences in regimen efficacy.RESULTS: Favourable outcomes (%) were significantly better with BPaL than with the B-L-based combination regimen (98/109, 89.9% vs. 56/86, 65.1%; adjusted relative risk ratio [aRRR] 1.35; P < 0.001) and in the matched pairwise analysis (67/75, 89.3% vs. 48/75, 64.0%; aRRR 1.39; P = 0.001), despite significantly higher baseline bacterial load and prior second-line drug exposure in the BPaL cohort. Time to culture conversion (P < 0.001), time to unfavourable outcome (P < 0.01) and time to death (P < 0.03) were significantly better or lower with BPaL than the B-L-based combinations.CONCLUSION: The BPaL regimen (and hence substitution of multiple other drugs by pretomanid and/or higher starting-dose LZD) may improve outcomes in drug-resistant TB patients with poor prognostic features. However, prospective controlled studies are required to definitively answer this question

    Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005)

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    COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18-65 years. South Africa's first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa's Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response. Clinical trial identifier: CT.gov NCT04444674

    Impact of volatile phenols and their precursors on wine quality and control measures of Brettanomyces/Dekkera yeasts

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    Volatile phenols are aromatic compounds and one of the key molecules responsible for olfactory defects in wine. The yeast genus Brettanomyces is the only major microorganism that has the ability to covert hydroxycinnamic acids into important levels of these compounds, especially 4-ethylphenol and 4-ethylguaiacol, in red wine. When 4-ethylphenols reach concentrations greater than the sensory threshold, all wine’s organoleptic characteristics might be influenced or damaged. The aim of this literature review is to provide a better understanding of the physicochemical, biochemical, and metabolic factors that are related to the levels of p-coumaric acid and volatile phenols in wine. Then, this work summarizes the different methods used for controlling the presence of Brettanomyces in wine and the production of ethylphenols

    Future research directions on the "elusive" white shark

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    White sharks, Carcharodon carcharias, are often described as elusive, with little information available due to the logistical difficulties of studying large marine predators that make long-distance migrations across ocean basins. Increased understanding of aggregation patterns, combined with recent advances in technology have, however, facilitated a new breadth of studies revealing fresh insights into the biology and ecology of white sharks. Although we may no longer be able to refer to the white shark as a little-known, elusive species, there remain numerous key questions that warrant investigation and research focus. Although white sharks have separate populations, they seemingly share similar biological and ecological traits across their global distribution. Yet, white shark’s behavior and migratory patterns can widely differ, which makes formalizing similarities across its distribution challenging. Prioritization of research questions is important to maximize limited resources because white sharks are naturally low in abundance and play important regulatory roles in the ecosystem. Here, we consulted 43 white shark experts to identify these issues. The questions listed and developed here provide a global road map for future research on white sharks to advance progress toward key goals that are informed by the needs of the research community and resource managers
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