59 research outputs found
Source Attribution of Human Campylobacteriosis Using Whole-Genome Sequencing Data and Network Analysis
Campylobacter spp. are a leading and increasing cause of gastrointestinal infections world-wide. Source attribution, which apportions human infection cases to different animal species and food reservoirs, has been instrumental in control-and evidence-based intervention efforts. The rapid increase in whole-genome sequencing data provides an opportunity for higher-resolution source attribution models. Important challenges, including the high dimension and complex structure of WGS data, have inspired concerted research efforts to develop new models. We propose network analysis models as an accurate, high-resolution source attribution approach for the sources of human campylobacteriosis. A weighted network analysis approach was used in this study for source attribution comparing different WGS data inputs. The compared model inputs consisted of cgMLST and wgMLST distance matrices from 717 human and 717 animal isolates from cattle, chickens, dogs, ducks, pigs and turkeys. SNP distance matrices from 720 human and 720 animal isolates were also used. The data were collected from 2015 to 2017 in Denmark, with the animal sources consisting of domestic and imports from 7 European countries. Clusters consisted of network nodes representing respective genomes and links representing distances between genomes. Based on the results, animal sources were the main driving factor for cluster formation, followed by type of species and sampling year. The coherence source clustering (CSC) values based on animal sources were 78%, 81% and 78% for cgMLST, wgMLST and SNP, respectively. The CSC values based on Campylobacter species were 78%, 79% and 69% for cgMLST, wgMLST and SNP, respectively. Including human isolates in the network resulted in 88%, 77% and 88% of the total human isolates being clustered with the different animal sources for cgMLST, wgMLST and SNP, respectively. Between 12% and 23% of human isolates were not attributed to any animal source. Most of the human genomes were attributed to chickens from Denmark, with an average attribution percentage of 52.8%, 52.2% and 51.2% for cgMLST, wgMLST and SNP distance matrices respectively, while ducks from Denmark showed the least attribution of 0% for all three distance matrices. The best-performing model was the one using wgMLST distance matrix as input data, which had a CSC value of 81%. Results from our study show that the weighted network-based approach for source attribution is reliable and can be used as an alternative method for source attribution considering the high performance of the model. The model is also robust across the different Campylobacter species, animal sources and WGS data types used as input
EFFECT OF ENTREPRENEUR CHARACTERISTICS ON PERFORMANCE OF NONTIMBER FOREST PRODUCTS SMALL AND MEDIUM ENTERPRISES IN KENYA
Limited literature is available on the relationship between entrepreneurcharacteristics and performance of non-timber forest products small and medium enterprisesraising debate whether the link is tenable with such firms. Thus, a study covering 314 small andmedium enterprises in nine counties in Kenya was conducted to explore the relationship. Thecoefficient of determination, F statistic, and the t-value and their significance levels were used inpresenting the relationship between entrepreneur characteristics and firm performance. The resultsshow that that firm performance is significantly affected by entrepreneur characteristics of age,managerial skills, industry experience and social skills. Thus, it is concluded that entrepreneurcharacteristics and performance of non-timber forest products small and medium enterprises areempirically related. Firms run by relatively young, well-experienced and skilled entrepreneursregister better performance. It is necessary, therefore, that the non-timber forest products small andmedium enterprises match their strategic decisions with characteristics of owners/managers toenhance their competitiveness and performance. The implications of this study are that specificpolicy measures are necessary to encourage the many well trained but unemployed young people toengage in businesses. Additionally it also implies that specific training programmes are necessaryto equip the practitioners with necessary theoretical and practical capacities to enhanceperformance of their firms
Simulation model for solar energy harnessing by the solar tunnel dryer
Models were developed to predict global solar radiation and the energy harnessed by a solar tunnel dryer, and simulated in Visual Basic 6. In addition, the simulated data were compared with actual data. Using a 10% absolute residual error interval, the developed model achieved 78.4% and 83.3% performance for global solar radiation and energy harnessing, respectively. Further, the relationship between global solar radiation and the ten years mean satellite solar radiation, and that between the actual and simulated plenum chamber temperatures were linear, with coefficients of determination (R2) of 0.788 and 0.962. Thus, it shows that there is the existence of strong correlation between satellite and predicted global solar radiation, and between predicted and actual plenum chamber temperatures. Furthermore, Student’s t-test did not show any significant difference between simulated and actual data for solar radiation and energy harnessing. Finally, this study shows that the developed model can be used to predict solar radiation and the energy harnessed by the solar tunnel dryer.Keywords: modeling, tunnel-dryer, global, direct, solar-radiation, plenum-temperature Citation: Kituu G. M., D. Shitanda, C. L. Kanali, J. T. Mailutha, C. K. Njoroge, J. K.Wainaina, and J. S Bongyereire. Simulation model for solar energy harnessing by the solar tunnel dryer. Agric Eng Int: CIGR Journal, 2010, 12(1): 91-98
From community to assemblage? : ICT provides a site for inclusion and exclusion in the global south
The role of information and communication technology (ICT) in development has been discussed from two distinctly different perspectives: some view it as a means for opening new alleys for the facilitation of development and democracy, while others assess it as counterproductive. Furthermore, it has been emphasised that people in cities and rural areas utilise ICT in different ways, as do people with wealth and education compared to poor people. In Africa, Kenya has declared itself an ICT hub. The state has emphasised ICT in promoting services, much less freedom of expression. This article discusses ICT and development via the filter of assemblage, a key concept developed by Deleuze and Guattari (2004/1980. A Thousand Plateaus: Capitalism and Schizophrenia. London: Continuum.). They emphasised fluidity as well as micro- and macro-level dichotomies. When communities based on sharing and consistent social order meet new technology, the change goes deeper than that of improved services. The basic difference might be the fact that a community is constructed on cultural ties developed over time, which strengthens immobility and stability, while an assemblage is characterised by mobility and fluidity. Thus, a system of values, hierarchies, and inherited traditions is challenged, mixed with ‘new’ problems brought about by individualised behaviour.Peer reviewe
Advances in Crop Improvement and Delivery Research for Nutritional Quality and Health Benefits of Groundnut (Arachis hypogaea L.)
Groundnut is an important global food and oil crop that underpins agriculture-dependent livelihood strategies meeting food, nutrition, and income security. Aflatoxins, pose a major challenge to increased competitiveness of groundnut limiting access to lucrative markets and affecting populations that consume it. Other drivers of low competitiveness include allergens and limited shelf life occasioned by low oleic acid profile in the oil. Thus grain off-takers such as consumers, domestic, and export markets as well as processors need solutions to increase profitability of the grain. There are some technological solutions to these challenges and this review paper highlights advances in crop improvement to enhance groundnut grain quality and nutrient profile for food, nutrition, and economic benefits. Significant advances have been made in setting the stage for marker-assisted allele pyramiding for different aflatoxin resistance mechanisms—in vitro seed colonization, pre-harvest aflatoxin contamination, and aflatoxin production—which, together with pre- and post-harvest management practices, will go a long way in mitigating the aflatoxin menace. A breakthrough in aflatoxin control is in sight with overexpression of antifungal plant defensins, and through host-induced gene silencing in the aflatoxin biosynthetic pathway. Similarly, genomic and biochemical approaches to allergen control are in good progress, with the identification of homologs of the allergen encoding genes and development of monoclonal antibody based ELISA protocol to screen for and quantify major allergens. Double mutation of the allotetraploid homeologous genes, FAD2A and FAD2B, has shown potential for achieving >75% oleic acid as demonstrated among introgression lines. Significant advances have been made in seed systems research to bridge the gap between trait discovery, deployment, and delivery through innovative partnerships and action learning
Glomerular filtration rate profiles in paediatric patients on cancer chemotherapy at the Kenyatta national hospital, kenya
Background: An accurate estimation of renal function in children is important in optimising the dose of many drugs used in paediatric oncology for allowing clinical monitoring of the nephrotoxic effects of cytotoxic agents such as cisplatin. The glomerular filtration rate (GFR) is widely accepted as the best index of renal function in patients. Chemotherapy is the mainstay of treatment in the paediatric oncology unit at the Kenyatta National Hospital.Objectives: To determine the glomerular filtration rate profiles of paediatric oncology patients and to assess changes that had occured over a period of at least six months of continuing cancer chemotherapy.Design: Cross-sectional hospital based survey.Setting: General Paediatric wards, including Paediatric Oncology and Paediatric Ophthalmology ward. Kenyatta National Hospital, Nairobi, Kenya.Subjects: Paediatric patients who had an established diagnosis of cancer and had been on chemotherapy for at least six months.Results: Out of the 115 children enrolled in the study 43 had abnormal kidney function. This gave a prevalence of 37% (95%CI 28-46).The other 72 children had normal kidney function. Patients aged less than five years and those with solid tumors had a higher likelihood of having an abnormal GFR compared to their older counterparts and those with lymphomas and leukemias.Conclusions: Monitoring of GFR should be done regularly as decline occurs as one continues on chemotherapy especially for the ones below five years and those with solid malignancies
Cost-benefit analysis of landscape restoration: A stocktake
With the increase in demand for landscape restoration and the limited resources available, there is need for economic analysis of landscape restoration to help prioritize investment of the resources. Cost-benefit analysis (CBA) is a commonly applied tool in the economic analysis of landscape restoration, yet its application seems limited and varied. We undertake a review of CBA applications to understand the breadth, depth, and gaps. Of the 2056 studies identified in literature search, only 31 met our predefined criteria. Three studies offered a global perspective, while more than half were conducted in Africa. Only six countries benefit from at least 2 CBA studies, including Brazil, Ethiopia, Kenya, Vietnam, South Africa, and Tanzania. About 60% focus on agroforestry, afforestation, reforestation, and assisted natural regeneration practices. Only 16% covered all cost categories, with opportunity costs being the least covered. Eighty-four percent apply direct use values, while only 16% captured the non-use values. Similarly, lack of reliable data due to predictions and assumptions involved in data generation influenced CBA results. The limited number of eligible studies and the weaknesses identified hereinabove suggest strong need for improvements in both the quantity and quality of CBA to better inform planning, policies, and investments in landscape restoration
Incentives for landscape restoration: Lessons from Shinyanga, Tanzania
Owing to high rates of land and forest degradation, there is consensus that forest landscape restoration is a global priority with the Bonn Challenge and the New York Declaration on Forests committing to restore about 350 Million hectares by 2030, globally. However, there is a need for incentives that motivate these restoration efforts and disincentives aimed at restricting activities that result in further land degradation. We provide insights and understanding of the incentives and disincentives measures applied within the forest restoration systems through a case study in the Shinyanga region of Tanzania. Incentives that have promoted forest landscape restoration in Shinyanga include; conservation benefits, education and information, Reducing Emissions from Deforestation and forest Degradation (REDD+), well-defined property rights & increasing land prices and awards while disincentives include; penalties, quotas and permits. Intrinsic incentives that are derived from self-desire within an individual such as conservation benefits and education & information were more preferred within Shinyanga region compared to extrinsic incentives which relied more on external factors such as REDD+ and awards. Nonetheless, a combination of both incentives and disincentives has led to the success of restoration in Shinyanga; positive incentives worked better for privately owned lands while regulatory disincentives worked better for communally owned restoration lands. High levels of social equity and trust have enabled the functioning of these incentives while a robust governance structure at the local level has been instrumental in enforcing the disincentives. There is need for government and all stakeholders to maintain and enhance the gains from restoration, especially empowering communities further, for these incentives to work
A Review of Global Policy Mechanisms Designed for Tropical Forests Conservation and Climate Risks Management
Deforestation and forest degradation of tropical forests are major global concerns due to their ecological, social, and economic roles. In the wake of climate change and its diverse global effects, fragmentation and degradation of tropical forests have jeopardized their ability to support livelihoods and regenerate climate regulating services. Concerted efforts by local, national, and international players, which are primarily scientific, technological, or economic, have borne minimal results in safeguarding these forests from destruction, necessitating a more integrated and inclusive approach. The Rio Earth Summit (1992) brought together world leaders to set targets and priorities on the global sustainability agenda and laid a strong foundation for international policy cooperation in the future. This study employed a systematic review of articles published between 1992 and 2020 to establish how various policy mechanisms have been developed and evolved to bridge forests and climate change discourse in tropical forests while highlighting their strengths and weaknesses. The initial search of peer-reviewed publications and gray literature yielded 2622 records, which were subjected to inclusion and exclusion criteria based on The Preferred Reporting Items for Systematic Review and Meta Analyses guidelines, resulting in a final list of 65 records for in-depth qualitative analysis. The study establishes that the mechanisms in place have contributed mainly to more coordination and incentives to manage climate risks, primarily through tropical forests conservation. However, hurdles such as inadequate participation and involvement of the local and indigenous people, insufficient national and local policy frameworks and bureaucracies around emissions monitoring, measuring, reporting, and verification processes continue to slow tropical forest conservation. Thus, there is a need for more integrated, multilevel, and diverse stakeholder engagement to achieve the set global targets effectively
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