127 research outputs found

    A Review of Research on Cryptogams of Malawi for the Past 30 years (1987-2016): Progress, Challenges and Way Forward

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    Cryptogams are a unique group of plants whose ecological role in ecosystems is indisputable. Cryptogams are a key determinant of ecosystem biogeochemistry and known to support above ground biomass, control soil chemistry, provide habitats to nitrogen fixing bacteria and provide are food to other organisms. Compared with higher plants, cryptogams remain the least studied in Malawi and globally. This review aimed at assessing the scope and extent of research on Malawi‟s cryptogams, existing challenges and opportunities. A review of published literature between 1987 and 2016 was done using online search engines and library sources. This review showed that algae and bryophytes are comparatively well-studied groups represented by 70 percent (%) of all literature on cryptogams, particularly in Lake Malawi and Mulanje Mountain respectively. The ferns are the least studied, comprising just 15% of the reviewed literature. Further, no traceable study of lichens was encountered. Cryptogam research in Malawi is thus limited. This limitation could be due to lack of expertise in the field, limited laboratory infrastructure capacity and a general lack of appreciation for their importance. Considering the threat the different ecosystem in Malawi face, it is recommended that; local expertise, participation and infrastructure be improved so as to enhance cryptogam research in Malawi. Such an approach would ensure an increased local awareness of the value of cryptogams and foster informed conservation prioritization for cryptogams in Malawi. Keywords: Cryptograms, challenges, conservation, research gaps, Malaw

    Factors affecting the performance of a manufacturing supply chain, and the organization

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    Abstract: Due to constant failure in delivering the products to customers on time the defence manufacturing organization introduced the supply chain phenomenon into its operations in an attempt to improve its performance (on-time delivery). This research aims to identify if supply chain performance is affected mainly by social or technical factors and also outline which of these factors have the highest effect on the performance of supply chain. The importance of this research is that it will determine if the performance of supply chain is affected by technical or social factors and also how the organization is affected by these factors. This research employed a case study and made use of both qualitative and quantitative data to allow for data triangulation in order to minimize biasness and increase the credibility of the results. The findings indicate that supply chain performance is affected by both social factors and technical factors, however the impact of these factors on both supply chain and the organization is different. In summary, this research will provide insight to the factors that affect the performance of supply chain and accordingly provide methods to minimize or eliminate these factors and therefore reducing their effect on supply chain and the organization

    A framework to investigate money attitudes and materialism

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    Purpose and/or objectives: This paper presents a framework to investigate money attitudes and materialistic values. The conceptualization of the framework is guided by a critical review of literature. The intention is to provide a framework that will be useful to examine how various childhood family experiences influence later-life consumption orientations. Problem investigated: The differences in family resources represent one of the biggest distinctions between an intact and a disrupted family. The underlining question is whether children raised in disrupted families will experience lower levels of family resources (economic and emotional) and find the experience stressful. If so, will these experiences influence them to adopt conservative money attitudes and be less materialistic or will they symbolically value money and be more materialistic? Design/methodology/approach: The development of a framework requires a critical review of secondary sources. The literature review is based on theories that provide an explanation of how childhood family experiences can affect the development of materialistic values and money attitudes. The secondary sources require careful scrutiny of journal articles, dissertations and essays in a number of libraries to provide more scholarly insight into the concepts and to assist in the conceptualisation of the framework. Findings and/or implications: Four main theories were found useful in conceptualizing the framework. They are Ryan and Deci's (2000) self-determination theory, Maslow's (1943) human need theory, Wicklund and Gollwitzer's (1982) symbolic self-completion theory and the life course theory contextualized by Moschis (2007). However, in line with Moschis' (2007) realization, the perspectives of the life course theory were found to be multi-disciplinary, multi-theoretical and thus innovative. They would therefore form the main theoretical guide for the design of the framework. Originality and/or value of the research: The paper provides a framework to investigate the moderating effect that money attitudes can have on how childhood family experiences influence later-life materialistic values. This proposed framework may form the building blocks for a number of empirical studies especially as the life course approach in studying consumption orientations is innovative and multidisciplinary. Conclusion: The framework includes as independent variable, childhood family structure. Depended variables are perceived level of family resources, stress and materialistic values. Money attitudes are regarded as moderating variables

    Ketamine Modulates the Neural Correlates of Reward Processing in Unmedicated Patients in Remission from Depression.

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    BACKGROUND: Ketamine as an antidepressant improves anhedonia as early as 2h post-infusion. These drug effects are thought to be exerted via actions on reward-related brain areas-yet, these actions remain largely unknown. Our study investigates ketamine's effects during the anticipation and receipt of an expected reward, after the psychotomimetic effects of ketamine have passed, when early antidepressant effects are reported. METHODS: We examined ketamine's effects during the anticipation and receipt of expected rewards on pre-defined brain areas, namely the dorsal and ventral striatum, the ventral tegmental area, the amygdala and the insula. We have recruited 37 male and female participants who remitted from depression and were free from symptoms and antidepressant treatments at the time of the scan. Participants were scanned, 2h after drug administration, in a double-blind cross over design (ketamine:0.5mg/kg and placebo) while performing a monetary reward task. RESULTS: A significant main effect of ketamine, across all ROIs, was observed during the anticipation and feedback phases of win and no-win trials. The drug effects were particularly prominent in the nucleus accumbens and putamen, which showed increased activation upon the receipt of smaller rewards compared to neutral. The levels of (2R,6R)-HNK, 2h post-infusion, significantly correlated with the activation observed in the ventral tegmental area for that contrast. CONCLUSIONS: These findings demonstrate that ketamine can produce detectable changes in reward-related brain areas, 2h after infusion, which occur without symptom changes and support the idea that ketamine might improve reward-related symptoms via modulation of response to feedback

    “Less is more”: A dose-response account of intranasal oxytocin pharmacodynamics in the human brain

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    Intranasal oxytocin is attracting attention as a potential treatment for several brain disorders due to promising preclinical results. However, translating findings to humans has been hampered by remaining uncertainties about its pharmacodynamics and the methods used to probe its effects in the human brain. Using a dose-response design (9, 18 and 36 IU), we demonstrate that intranasal oxytocin-induced changes in local regional cerebral blood flow (rCBF) in the amygdala at rest, and in the covariance between rCBF in the amygdala and other key hubs of the brain oxytocin system, follow a dose-response curve with maximal effects for lower doses. Yet, the effects on local rCBF might vary by amygdala subdivision, highlighting the need to qualify dose-response curves within subregion. We further link physiological changes with the density of the oxytocin receptor gene mRNA across brain regions, strengthening our confidence in intranasal oxytocin as a valid approach to engage central targets. Finally, we demonstrate that intranasal oxytocin does not disrupt cerebrovascular reactivity, which corroborates the validity of haemodynamic neuroimaging to probe the effects of intranasal oxytocin in the human brain. Data availability: Participants did not consent for open sharing of the data. Therefore, data can only be accessed from the corresponding author upon reasonable reques

    Can Famine Be Averted? A Spatiotemporal Assessment of The Impact of Climate Change on Food Security in The Luvuvhu River Catchment of South Africa

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    Climate change has proved to be a threat to food security the world over. Using temperature and precipitation data, this paper examines the differential effects climate change has on different land uses in the Luvuvhu river catchment in South Africa. The paper uses the Normalised Difference Vegetation Index (NDVI) and Vegetation Condition Index (VCI), which were calculated from Landsat images, and the Standardised Precipitation Index (SPI) for a sample of years between 1980 and 2016 to assess how drought and flood frequency have affected the agricultural environment. The results indicate that the lowest SPI values were recorded in 1996/1997, 2001/2002 and 2014/2015, suggesting the occurrence of drought during these years, while the highest SPI values were recorded in 1997/1998, 2002/2003 and 2004/2005. The relationship between three-month SPI (SPI_3) and VCI was strongest in grassland, and subsistence farming areas with the correlation coefficients of 0.8166 (p = 0.0022) and −0.6172 (p = 0.0431), respectively, indicating that rainfall variability had a high negative impact on vegetation health in those land uses with shallow-rooted plants. The findings of this study are relevant to disaster management planning in South Africa, as well as development of farming response strategies for coping with climate hazards in the country.</jats:p

    Barriers and facilitators to combined ART initiation in pregnant women with HIV: lessons learnt from a PMTCT B+ pilot program in Swaziland

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    In January 2013, Swaziland launched a PMTCT B+ implementation study in rural Shiselweni. We aimed to identify patient and health service determinants of combined antiretroviral therapy (ART) initiation, to help guide national implementation of PMTCT B+

    Discrepancy between Mtb-specific IFN-γ and IgG responses in HIV-positive people with low CD4 counts

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    Background: Tuberculosis (TB) is a leading infectious cause of death worldwide and treating latent TB infection (LTBI) with TB preventative therapy is a global priority. This study aimed to measure interferon gamma (IFN-γ) release assay (IGRA) positivity (the current reference standard for LTBI diagnosis) and Mtb-specific IgG antibodies in otherwise healthy adults without HIV and those living with HIV (PLWH). Methods: One-hundred and eighteen adults (65 without HIV and 53 antiretroviral-naïve PLWH), from a peri-urban setting in KwaZulu-Natal, South Africa were enrolled. IFN-γ released following stimulation with ESAT-6/CFP-10 peptides and plasma IgG antibodies specific for multiple Mtb antigens were measured using the QuantiFERON-TB Gold Plus (QFT) and customized Luminex assays, respectively. The relationships between QFT status, relative concentrations of anti-Mtb IgG, HIV-status, sex, age and CD4 count were analysed. Findings: Older age, male sex and higher CD4 count were independently associated with QFT positivity (p = 0.045, 0.05 and 0.002 respectively). There was no difference in QFT status between people with and without HIV infection (58% and 65% respectively, p = 0.06), but within CD4 count quartiles, people with HIV had higher QFT positivity than people without HIV (p = 0.008 (2nd quartile), <0.0001 (3rd quartile)). Concentrations of Mtb-specific IFN-γ were lowest, and relative concentrations of Mtb-specific IgGs were highest in PLWH in the lowest CD4 quartile. Interpretation: These results suggest that the QFT assay underestimates LTBI among immunosuppressed people with HIV and Mtb-specific IgG may be a useful alternative biomarker for Mtb infection. Further evaluation of how Mtb-specific antibodies can be leveraged to improve LTBI diagnosis is warranted, particularly in HIV-endemic areas. Fundings: NIH, AHRI, SHIP: SA-MRC and SANTHE

    Effectiveness of a combination strategy for linkage and retention in adult HIV care in Swaziland: The Link4Health cluster randomized trial

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    Background: Gaps in the HIV care continuum contribute to poor health outcomes and increase HIV transmission. A combination of interventions targeting multiple steps in the continuum is needed to achieve the full beneficial impact of HIV treatment. Methods and findings: Link4Health, a cluster-randomized controlled trial, evaluated the effectiveness of a combination intervention strategy (CIS) versus the standard of care (SOC) on the primary outcome of linkage to care within 1 month plus retention in care at 12 months after HIV-positive testing. Ten clusters of HIV clinics in Swaziland were randomized 1:1 to CIS versus SOC. The CIS included point-of-care CD4+ testing at the time of an HIV-positive test, accelerated antiretroviral therapy (ART) initiation for treatment-eligible participants, mobile phone appointment reminders, health educational packages, and noncash financial incentives. Secondary outcomes included each component of the primary outcome, mean time to linkage, assessment for ART eligibility, ART initiation and time to ART initiation, viral suppression defined as HIV-1 RNA < 1,000 copies/mL at 12 months after HIV testing among patients on ART ≥6 months, and loss to follow-up and death at 12 months after HIV testing. A total of 2,197 adults aged ≥18 years, newly tested HIV positive, were enrolled from 19 August 2013 to 21 November 2014 (1,096 CIS arm; 1,101 SOC arm) and followed for 12 months. The median participant age was 31 years (IQR 26–39), and 59% were women. In an intention-to-treat analysis, 64% (705/1,096) of participants at the CIS sites achieved the primary outcome versus 43% (477/1,101) at the SOC sites (adjusted relative risk [RR] 1.52, 95% CI 1.19–1.96, p = 0.002). Participants in the CIS arm versus the SOC arm had the following secondary outcomes: linkage to care regardless of retention at 12 months (RR 1.08, 95% CI 0.97–1.21, p = 0.13), mean time to linkage (2.5 days versus 7.5 days, p = 0.189), retention in care at 12 months regardless of time to linkage (RR 1.48, 95% CI 1.18–1.86, p = 0.002), assessment for ART eligibility (RR 1.20, 95% CI 1.07–1.34, p = 0.004), ART initiation (RR 1.16, 95% CI 0.96–1.40, p = 0.12), mean time to ART initiation from time of HIV testing (7 days versus 14 days, p < 0.001), viral suppression among those on ART for ≥6 months (RR 0.97, 95% CI 0.88–1.07, p = 0.55), loss to follow-up at 12 months after HIV testing (RR 0.56, 95% CI 0.40–0.79, p = 0.002), and death (N = 78) within 12 months of HIV testing (RR 0.80, 95% CI 0.46–1.35, p = 0.41). Limitations of this study include a small number of clusters and the inability to evaluate the incremental effectiveness of individual components of the combination strategy. Conclusions: A combination strategy inclusive of 5 evidence-based interventions aimed at multiple steps in the HIV care continuum was associated with significant increase in linkage to care plus 12-month retention. This strategy offers promise of enhanced outcomes for HIV-positive patients

    Cognitive deficits in people who have recovered from COVID-19.

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    BACKGROUND: There is growing concern about possible cognitive consequences of COVID-19, with reports of 'Long COVID' symptoms persisting into the chronic phase and case studies revealing neurological problems in severely affected patients. However, there is little information regarding the nature and broader prevalence of cognitive problems post-infection or across the full spread of disease severity. METHODS: We sought to confirm whether there was an association between cross-sectional cognitive performance data from 81,337 participants who between January and December 2020 undertook a clinically validated web-optimized assessment as part of the Great British Intelligence Test, and questionnaire items capturing self-report of suspected and confirmed COVID-19 infection and respiratory symptoms. FINDINGS: People who had recovered from COVID-19, including those no longer reporting symptoms, exhibited significant cognitive deficits versus controls when controlling for age, gender, education level, income, racial-ethnic group, pre-existing medical disorders, tiredness, depression and anxiety. The deficits were of substantial effect size for people who had been hospitalised (N = 192), but also for non-hospitalised cases who had biological confirmation of COVID-19 infection (N = 326). Analysing markers of premorbid intelligence did not support these differences being present prior to infection. Finer grained analysis of performance across sub-tests supported the hypothesis that COVID-19 has a multi-domain impact on human cognition. INTERPRETATION: Interpretation. These results accord with reports of 'Long Covid' cognitive symptoms that persist into the early-chronic phase. They should act as a clarion call for further research with longitudinal and neuroimaging cohorts to plot recovery trajectories and identify the biological basis of cognitive deficits in SARS-COV-2 survivors. FUNDING: Funding. AH is supported by the UK Dementia Research Institute Care Research and Technology Centre and Biomedical Research Centre at Imperial College London. WT is supported by the EPSRC Centre for Doctoral Training in Neurotechnology. SRC is funded by a Wellcome Trust Clinical Fellowship 110,049/Z/15/Z. JMB is supported by Medical Research Council (MR/N013700/1). MAM, SCRW and PJH are, in part, supported by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London
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