147 research outputs found

    Invasive Water Hyacinth Challenges, Opportunities, Mitigation, and Policy Implications: The Case of the Nile Basin

    Get PDF
    Many lakes and rivers all over the globe are experiencing environmental, human health, and socio-economic development issues due to the spread of invasive water hyacinth (WH) weed. WH is regarded as one of the world’s most destructive weeds and is nearly impossible to control and eliminate due to its rapid expansion and ability to double its coverage area in 13 days or fewer. However, most people in developing countries appear to be hoping for a miraculous cure; there are none and never will be. In this regard, this chapter aims to give an insight to raise awareness, research its biology and challenges, management options, and potential prospects on integrated control-valorization and its policy implications. WH biomass has demonstrated potential as a biorefinery feedstock for bioenergy and biofertilizer production, heavy metal phytoremediation, handicraft and furniture making, animal feed, and other applications. As a result, large-scale integrated control and valorization is an economically viable strategy for preventing further infestation through incentivizing WH control: providing a sustainable environment, increasing energy mix, increasing fertilizer mix, increasing food security, reducing GHG emissions, boosting socio-economic development, and creating new green jobs for local and riparian communities. Therefore, it is a leap forward in addressing global sustainable development goals (SDGs) through the water-energy-food-ecosystem (WEFE) nexus

    Pro-opiomelanocortin and ACTH–cortisol dissociation during pediatric cardiac surgery

    Get PDF
    In critically ill adults, high plasma cortisol in the face of low ACTH coincides with high pro-opiomelanocortin (POMC) levels. Glucocorticoids further lower ACTH without affecting POMC. We hypothesized that in pediatric cardiac surgery-induced critical illness, plasma POMC is elevated, plasma ACTH transiently rises intraoperatively but becomes suppressed post-operatively, and glucocorticoid administration amplifies this phenotype. From 53 patients (0–36 months), plasma was obtained pre-operatively, intraoperatively, and on post-operative days 1 and 2. Plasma was also collected from 24 healthy children. In patients, POMC was supra-normal pre-operatively (P &lt; 0.0001) but no longer thereafter (P &gt; 0.05). ACTH was never high in patients. While in glucocorticoid-naive patients ACTH became suppressed by post-operative day 1 (P &lt; 0.0001), glucocorticoid-treated patients had already suppressed ACTH intraoperatively (P ≤ 0.0001). Pre-operatively high POMC, not accompanied by increased plasma ACTH, suggests a centrally activated HPA axis with reduced pituitary processing of POMC into ACTH. Increasing systemic glucocorticoid availability with glucocorticoid treatment accelerated the suppression of plasma ACTH. Significance statement Glucocorticoids are often administered during pediatric cardiac surgery. In critically ill children, endogenous systemic glucocorticoid availability is elevated already upon ICU admission while ACTH levels are normal. This hormonal constellation suggests the presence of active feedback inhibition of ACTH. In this study, we have documented that intraoperative administration of glucocorticoids accelerates the suppression of ACTH, resulting in low plasma ACTH already upon ICU admission. Pre-operative plasma POMC, the ACTH precursor, but not ACTH, was increased. This is compatible with a centrally activated HPA axis prior to surgery in young children but reduced processing of POMC into ACTH within the pituitary. These findings suggest that glucocorticoid treatment in the context of pediatric cardiac surgery may amplify pre-existing impaired pituitary processing of the prohormone POMC.</p

    Pro-opiomelanocortin and ACTH–cortisol dissociation during pediatric cardiac surgery

    Get PDF
    In critically ill adults, high plasma cortisol in the face of low ACTH coincides with high pro-opiomelanocortin (POMC) levels. Glucocorticoids further lower ACTH without affecting POMC. We hypothesized that in pediatric cardiac surgery-induced critical illness, plasma POMC is elevated, plasma ACTH transiently rises intraoperatively but becomes suppressed post-operatively, and glucocorticoid administration amplifies this phenotype. From 53 patients (0–36 months), plasma was obtained pre-operatively, intraoperatively, and on post-operative days 1 and 2. Plasma was also collected from 24 healthy children. In patients, POMC was supra-normal pre-operatively (P &lt; 0.0001) but no longer thereafter (P &gt; 0.05). ACTH was never high in patients. While in glucocorticoid-naive patients ACTH became suppressed by post-operative day 1 (P &lt; 0.0001), glucocorticoid-treated patients had already suppressed ACTH intraoperatively (P ≤ 0.0001). Pre-operatively high POMC, not accompanied by increased plasma ACTH, suggests a centrally activated HPA axis with reduced pituitary processing of POMC into ACTH. Increasing systemic glucocorticoid availability with glucocorticoid treatment accelerated the suppression of plasma ACTH. Significance statement Glucocorticoids are often administered during pediatric cardiac surgery. In critically ill children, endogenous systemic glucocorticoid availability is elevated already upon ICU admission while ACTH levels are normal. This hormonal constellation suggests the presence of active feedback inhibition of ACTH. In this study, we have documented that intraoperative administration of glucocorticoids accelerates the suppression of ACTH, resulting in low plasma ACTH already upon ICU admission. Pre-operative plasma POMC, the ACTH precursor, but not ACTH, was increased. This is compatible with a centrally activated HPA axis prior to surgery in young children but reduced processing of POMC into ACTH within the pituitary. These findings suggest that glucocorticoid treatment in the context of pediatric cardiac surgery may amplify pre-existing impaired pituitary processing of the prohormone POMC.</p

    Opportunities and Challenges of Harnessing Biomass Wastes for Decentralized Heat and Energy Generation and Climate Mitigation via Fluidized-bed Gasification Pathway

    Get PDF
    Biomass wastes offer immense potential as a renewable energy source, holding the promise to replace fossil fuels for heat and energy generation, in particular for decentralized power production. Furthermore, the utilization of biomass promotes circular economy by enabling the conversion of local resources into useful products and energy. However, the conversion of biomass into end-use products and heat/energy is a complex process with multiple pathways, such as fluidized bed gasification, a well-established and efficient method for converting coal and biomass into heat. Despite its merits, this process is currently limited to industrial applications and encounters certain limitations and obstacles. Notably, the low energy density of biomass wastes and downstream pipe contamination from tar and polycyclic aromatic hydrocarbon (PAH) growth poses significant technological challenges. Nonetheless, a roadmap has been developed to guide the widespread adoption of fluidized bed gasification of biomass for decentralized power generation and climate mitigation. This book chapter delves into the opportunities and challenges of fluidized bed gasification as a viable option for decentralized power generation and climate mitigation through biomass waste conversion. The significance of well-crafted policies supporting renewable energy sources and optimizing fluidized bed gasifiers to achieve desirable end products are also emphasized

    Development of a portfolio of learning for postgraduate family medicine training in South Africa: a Delphi study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Within the 52 health districts in South Africa, the family physician is seen as the clinical leader within a multi-professional district health team. Family physicians must be competent to meet 90% of the health needs of the communities in their districts. The eight university departments of Family Medicine have identified five unit standards, broken down into 85 training outcomes, for postgraduate training. The family medicine registrar must prove at the end of training that all the required training outcomes have been attained. District health managers must be assured that the family physician is competent to deliver the expected service. The Colleges of Medicine of South Africa (CMSA) require a portfolio to be submitted as part of the uniform assessment of all registrars applying to write the national fellowship examinations. This study aimed to achieve a consensus on the contents and principles of the first national portfolio for use in family medicine training in South Africa.</p> <p>Methods</p> <p>A workshop held at the WONCA Africa Regional Conference in 2009 explored the purpose and broad contents of the portfolio. The 85 training outcomes, ideas from the WONCA workshop, the literature, and existing portfolios in the various universities were used to develop a questionnaire that was tested for content validity by a panel of 31 experts in family medicine in South Africa, via the Delphi technique in four rounds. Eighty five content items (national learning outcomes) and 27 principles were tested. Consensus was defined as 70% agreement. For those items that the panel thought should be included, they were also asked how to provide evidence for the specific item in the portfolio, and how to assess that evidence.</p> <p>Results</p> <p>Consensus was reached on 61 of the 85 national learning outcomes. The panel recommended that 50 be assessed by the portfolio and 11 should not be. No consensus could be reached on the remaining 24 outcomes and these were also omitted from the portfolio. The panel recommended that various types of evidence be included in the portfolio. The panel supported 26 of the 27 principles, but could not reach consensus on whether the portfolio should reflect on the relationship between the supervisor and registrar.</p> <p>Conclusion</p> <p>A portfolio was developed and distributed to the eight departments of Family Medicine in South Africa, and the CMSA, to be further tested in implementation.</p
    • …
    corecore