413 research outputs found
1-Methylcyclopropene (1-MCP) effects on natural disease resistance in stored sweetpotato
BACKGROUND
The potential of 1-methylcyclopropene (1-MCP) to maintain postharvest storage of sweetpotato was studied. In two separate experiments, the orange-fleshed sweetpotato cv. Covington was fumigated with 1-MCP (1.0 μL L-1, 24 h) and roots stored at 15 oC. During storage, samples were evaluated for the respiration rate, sprout growth, weight loss, incidence of decay and changes in dry matter. The roots were further assayed for the temporal changes in individual non-structural carbohydrates and phenolic compounds in the skin and flesh tissues of the proximal (stem end), middle, and distal (root end) regions.
RESULTS
1-MCP treatment reduced root weight loss and decay but respiration rate and non-structural carbohydrates were not affected. No sprouting was recorded irrespective of the treatment. 1-MCP transiently suppressed the accumulation of individual phenolic compounds, especially in the middle and distal segments. This accentuated the proximal dominance of phenolic compounds. Isochlorogenic acid A and chlorogenic acid were the dominant phenolics in the skin and flesh tissues, respectively.
CONCLUSION
1-MCP treatment may have anti-decay effect and reduce weight loss. Therefore, storage trials which involve the use of continuous ethylene supplementation to inhibit sprout growth may be combined with 1-MCP to alleviate ethylene-induced weight loss and decay in sweetpotato
Design and construction of a flexible laboratory-scale mixing apparatus for continuous ethylene supplementation of fresh produce
The design and construction of a laboratory-scale apparatus for generating variable concentrations and flow rates of exogenous ethylene for fresh produce supplementation during storage trials is described. A stock of compressed ethylene in nitrogen (5000 μl l−1) was blended into a continuous flow stream of air and diluted to the desired concentrations. The ethylene and air flow rates were controlled with calibrated mass flow control valves. An empirical mathematical model was derived for real-time variation of both the mixed concentration and flow rate during continuous flow. Validation of the model was performed using fresh sweet potato as a case study where a steady continuous ethylene concentration of 10 μl l−1 was achieved for three months. The bespoke system offers easy-to-manage ethylene supplementation for research
Green Supply Chain Management and Environmental Performance: The moderating role of Firm Size
This study examined the impact of internal and external green supply chain practices on environmental performance among construction firms. The study used the quantitative survey research design in its methodology. A total of 217 employees were sampled from fifty (50) construction firms. Structural Equation Modeling was used to analyze the data. The results showed that green design does not have a significant positive relationship with environmental performance. However, green design has a positive impact on external green practices namely green purchasing and green construction. Green purchasing and green construction have direct positive relationships with environmental performance. Green design through external green practices have a significant positive relationship with environmental performance. The study found that firm size moderates the relationship between green design, through external green supply chain practices and environmental performance among construction firms
Factors associated with the utilisation of skilled delivery services in Papua New Guinea: evidence from the 2016–2018 Demographic and Health Survey
BackgroundWe sought to determine the prevalence and factors associated with the use of skilled assistance during delivery in Papua New Guinea.MethodsWe analysed nationally representative data from 5210 women in Papua New Guinea using the 2016-2018 Demographic and Health survey. Both bivariate and multivariable analyses were performed. Statistical significance was set at pResultsThe prevalence of skilled assistance during delivery was 57.6%. The richest women (adjusted OR [AOR]=3.503, 95% CI 2.477 to 4.954), working women (AOR=1.221, 95% CI 1.037 to 1.439), women with primary (AOR=1.342, 95% CI 1.099 to 1.639), secondary or higher education (AOR=2.030, 95% CI 1.529 to 2.695), women whose partners had a secondary or higher level of education (AOR=1.712, 95% CI 1.343 to 2.181], women who indicated distance was not a big problem in terms of healthcare (AOR=1.424, 95% CI 1.181 to 1.718), women who had ≥4 antenatal care (ANC) visits (AOR=10.63, 95% CI 8.608 to 13.140), women from the Islands region (AOR=1.305, 95% CI 1.045 to 1.628), those who read newspapers or magazines (AOR=1.310, 95% CI 1.027 to 1.669) and women who watched television (AOR=1.477, 95% CI 1.054 to 2.069) less than once a week had higher odds of utilising skilled attendants during delivery. On the contrary, women in the Momase region (AOR=0.543, 95% CI 0.438 to 0.672), women in rural areas (AOR=0.409, 95% CI 0.306 to 0.546), as well as women with a parity of 3 (AOR=0.666, 95% CI 0.505 to 0.878) or ≥4 (AOR=0.645, 95% CI 0.490 to 0.850) had lower odds of utilising skilled attendance during delivery.ConclusionThere is relatively low use of skilled delivery services in Papua New Guinea. Wealth, employment status, educational level, parity and number of ANC visits, as well as access to healthcare and place of residence, influence the utilisation of skilled delivery services
Influence of Parasitic Worm Infections on Allergy Diagnosis in Sub-Saharan Africa.
Epidemiological studies from Sub-Saharan Africa indicate that allergies are on the rise in this region especially in urban compared to rural areas. This increase has been linked to improved hygiene, lifestyle changes, and lower exposure to pathogens in childhood. Reduced exposure to parasitic worm (helminth) infections and allergy outcomes has been the focus of a number of population studies over the years. Paradoxically, there are parallels in the immune responses to helminths and to allergies. Both conditions are associated with elevated levels of immunoglobulin E, high numbers of T helper 2 cells, eosinophils, and mast cells. These immune parallels have meant that the diagnosis of allergies in parts of the world where helminths are endemic can be hampered. The aim of this review is to examine observations from population studies conducted in Sub-Saharan Africa that demonstrate how helminth infections influence the parameters used to diagnose allergy outcomes in this region. We explore specifically how helminth infections hinder the in vitro diagnosis of allergic sensitization, influence the clinical manifestations of allergy, and also the effect of anthelmintic treatment on allergy outcomes. Advancing our understanding of how helminths influence allergy diagnosis is imperative for the development of improved tools to assess, diagnose, and treat allergic disorders in both helminth-endemic and non-endemic countries worldwide
Yield, biochemical properties and cooking quality traits of sweet potatoes (Ipomoea batatas) as affected by Nitrogen and Potassium Fertilizer rates
This study evaluated the effects of mineral fertilizer rates on biochemical properties, cooking quality traits and root yield of sweetpotatoes. The experimental design was 4 x 4 factorial in randomized complete block with three replications. The treatment factors were four varieties of sweetpotato (Ligri, Bohye, Dadanyuie and Apomuden) and four fertilizer amendments (T1: 30-30-30 kg /ha NPK, T2: 30-30-60 kg NPK+50 kg Muriate of Potash, T3: 30-30-90 kg/ha NPK+ 100 kg Muriate of Potash and T4: Control (No fertilizer). Results showed that the fertilizer rates did not influence root yield but variety had significant difference (P<0.05). Apomuden recorded the highest average root yield of 14.5 t/ha which was significantly higher than Ligri 5.1 t/ha. Ligri recorded the highest dry matter and sugar contents of 34.63% and 67.98% respectively while Apomuden recorded the lowest dry matter content and starch content of 23.75% and 50.00% respectively. However, it recorded appreciable amount of beta-carotene and sugar contents of 32.38 mg/100g and 28.04% respectively. There were significant variety × location interactions effect (P < 0.05) on average root yield and biomass yield. The significant varietal response observed in this study implies that choice of variety is an important factor to consider in sweetpotato production
Additive manufacturing interventions during the covid-19 pandemic: South Africa
Additive manufacturing (AM), also known as 3D printing, is considered a renaissance of the manufacturing industry. Its unique capability of manufacturing 3D objects with intricate geometrical configurations has been used to produce hospital equipment and personal protective equipment (PPE) in an attempt to curb the spread of the COVID-19 pandemic in South Africa. The technology has been used by different research units to produce ventilators, respirator face masks, oscillating respiratory devices, oxygen connectors, oxygen splitters, non-invasive ventilation helmets, reusable clinician PPE, visor frames for face shields, etc. Despite the efforts of the AM community in South Africa, COVID-19 infections have continued to increase in the country. It came to light that technological interventions (including AM) alone cannot prevent the spread of the virus without the corresponding adaptive behavioural changes, such as adhering to COVID-19 prevention protocols (washing of hands, social distancing, etc.). It could be postulated that the spread of COVID-19 can only be prevented by inter-marrying the technological interventions (AM) with adaptive behavioural changes
The Effects of Business Failure Experience on Successive Entrepreneurial Engagements: An Evolutionary Phase Model
This study draws insights from the literatures on entrepreneurial learning from failure and organizational imprinting to develop an evolutionary phase model to explain how prior business failure experience influences successive newly started businesses. Using multiple case studies of entrepreneurs located in an institutionally developing society in Sub-Sahara Africa, we uncover four distinctive phases of post-entrepreneurial business failure: grief and despair, transition, formation and legacy phases. We find that while the grieving and transition phases entailed processes of reflecting and learning lessons from the business failure experiences, the formation and legacy phases involve processes of imprinting entrepreneurs’ experiential knowledge on their successive new start-up firms. We conclude by outlining a number of fruitful avenues for future research
Sustainability orientation, CSR implementation and new venture growth
Purpose: Building on the upper echelons theory and sustainability orientation (SO) literature, we examined the possibility that the relationship between chief executive officers’ (CEOs’) SO and venture growth might be mediated by levels of CSR implementation. Design/methodology/approach: We used data obtained from from 211 new ventures operating in Ghana. Multiple regression analysis was used to test the hypotheses. Findings: We found that CSR implementation mediates the relationship between SO and venture growth. In addition, we found that, at higher levels of financial slack, the effect of SO on CSR implementation is attenuated. However, our results show that, at higher levels of CEO power, the influence of SO on CSR implementation is amplified. Originality: To the best of our knowledge, this study is among the first to examine mediating role of CSR implementation in the relationship between SO and venture growth, and also, examines two internal contingency factors (i.e., CEO power and financial slack) on this association. Theoretical/Academic Implications: This study builds on prior scholarly works by articulating a key managerial characteristic that shapes the implementation of environmental and social policies. Specifically, we show that SO influences venture growth through CSR implementation. We also provide insights on the connection of CSR implementation to growth of new business ventures. Practitioner/Policy Implications: Our study encourages CEOs to voluntarily adopt CSR and sustainability initiatives. The analysis also reinforces the need that higher levels of CEO power have a major impact in amplifying the effects of sustainability orientation on degree of CSR implementation. There is a need for government to create forums where organizational decisionmakers, i.e., CEOs, exchange not only the best knowledge about CSR implementation and sustainability, but also best practices to provide opportunities for cross fertilization of ideas and increased innovations
Моделирование профилактических и защитных мер от инсайдерской угрозы
Проведено исследование эффективных мер по предотвращению саботажа на ядерных объектах и хищения радиационных материалов. В исследовании используются эффективные превентивные и защитные меры, которые были реализованы в институте, чтобы показать надежность гипотетического объекта. Цепи Маркова, которые представляют собой комбинацию вероятностей и матричных операций, моделируют превентивные и защитные меры на гипотетической ядерной установке. Результаты реализуются в процессе оценки реализованных стратегий. Некоторые из процессов оценки включают разработанные алгоритмы предотвращения длительных и / или внезапных краж, саботажа и сговора между внутренними нарушителями. Следовательно, эффективность превентивных и защитных мер против злоумышленников также зависит от эффективности процесса оценки, проводимого экспертами
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