141 research outputs found
Key limitations of fish feeds, feed management practices, and opportunities in Kenyaâs aquaculture enterprise
Profitability is key in fish farming, just as it is to any other enterprise. For the farmers to actualize high-profit margins, it is imperative to have access to well-balanced nutritive and cost-effective feeds, backed by sound on-farm feed management practices. This paper audits Kenyaâs fish feed industry and the on-going on-farm feed management practices, and emerging opportunities for fish farmers. The development of fish feed quality standards has boosted the aquaculture sector in Kenya, providing them hope that farmers will access high quality fish feeds. Much of the fish feed currently being used in Kenya is produced on-farm or by small-scale fish feed manufacturers within the East African region, while a few are imported directly from overseas countries, notably Israel, Netherlands, Mauritius and Denmark. Fish feeds produced by small-scale manufacturers are not closely monitored by quality standard agencies and not surprising that a majority are of poor quality. The improvement in the quality of these feeds is likely to lead to increased productivity and profitability because they are cheaper and readily available to fish farmers, compared to imported fish feeds. Besides feed quality, feed management practices markedly impact both the growth and economic performance of fish production. Adopting appropriate feed management strategies, therefore, is instrumental in the maximization of fish production and economic returns. Research has demonstrated several strategies for best feed management practices, which have not hitherto, been adopted by fish farmers in Kenya. Farmers have mainly focused on the mode of delivery of feeds to the fish. Furthermore, promoting natural pond productivity and supplementary feeding is still a common practice in the East African region. Provision of species-specific feeds and targeting the nutritional requirements of the different life stages of fish is still a major issue, although some local companies like Unga Farm Care (EA) have come up with a size and species-specific feed for catfish such as Fugo catfishÂź. To improve access to such information, public-private partnerships should be developed and, programmes that utilize the local media platforms such as extension service outlets must also be encouraged. Feed quality checks can also be carried out amongst fish feed suppliers. Lastly, farmers should be trained in various fish feed aspects like formulation, transportation and storage to sustain a steady fish feed supply and save on associated feed costs
Adolescent Problem Gambling in Rural Ghana: Prevalence and Gender Differentiation
Abstract
Problem gambling among young people is now a public health challenge in sub-Saharan Africa. However, the behaviour remains understudied, particularly, among rural-dwelling young people in countries within the subregion. We aimed to estimate the 12 months prevalence of problem gambling and to describe the overall and gender differences and commonalities in personal factors and social adversities associated with problem gambling among adolescents in rural Ghana. We conducted a cross-sectional survey involving a random sample of 1101 in-school adolescents aged 10â19 years in a rural district in Eastern Ghana; we used the DSM-IV-Multiple Response-Juvenile (DSM-IV-MR-J) questionnaire to assess problem gambling during the previous 12 months. Personal lifestyle and psychosocial variables were assessed using adopted items from the 2012 WHOâGlobal School-based Student Health Survey. Overall, three in 10 adolescents (3 in 10 females; 4 in 10 males) in rural Ghana reported problem gambling in the previous 12 months. Female adolescents who experienced problem gambling were more likely to report family-related social adversities, while adolescent male problem gambling was associated with school-related factors and interpersonal factors outside the family context. Regardless of gender, sexual abuse victimisation was associated with three times increase in the odds of experiencing problem gambling. Relative to the prevalence of gambling among adolescents in urban contexts in other countries within sub-Saharan Africa, the estimates of problem gambling among in-school rural adolescents in Ghana are higher. Although further studies are needed to understand the nuances of the behaviour, the evidence of this study underscores the need for general and targeted health promotion, intervention and prevention efforts to mitigate the family, school, and interpersonal social adversities associated with adolescent problem gambling in rural Ghana.</jats:p
Developing and maintaining national food safety control systems: Experiences from the WHO African region
The establishment of effective food safety systems is pivotal to ensuring the safety of the national food supply as well as food products for regional and international trade. The development, structure and implementation of modern food safety systems have been driven over the years by a number of developments. These developments include: a reorientation of quality assurance protocols; emphasis on the development of integrated and holistic food safety systems with a farm-to-table approach; increasedrecognition of the respective roles of the different stakeholders along the food chain; increased food trade coupled with obligations under trade agreements; and advances in the control of foodborne hazards. At its core, a modern food safety system includes enabling food laws, policies, regulations and standards; mechanisms for coordination; operational food inspection and laboratory services as well as national information,education and communication programmes. While progress has been made in some countries in the WHO African Region at modernizing their food safety systems, many others are still grappling with the basics for development of effective food control systems. The traditional food control systems in a number of African countries do not provide the concerned agencies with a clear mandate and authority to prevent food safety problems. Effective food control in a number of these countries is undermined by a number of challenges including limited awareness about food safety, inadequate enabling policy, outdated legislation and regulations; inadequate coordination; and inadequate capacity and resources for food safety. This paper reviews the components of a modern national food safety control system and examines efforts at strengthening national food safety control systems in the African Region. It includesexperiences from countries that have made efforts at strengthening their national food safety control systems in view of current developments. The paper further discusses some of the challenges of food control systems in the Region and prospects for improvements. It concludes by suggesting the way forward for improving national food safety control systems in the Region
Synthesis, characterization and DPPH scavenging activity of some benzimidazole derivatives
A base-catalyzed conversion of aldehydes to benzimidazoles has been achieved. The compounds have been characterized by IR, NMR, micoranalysis, and GC-MS. The reaction for the formation of benzimidazoles has been monitored with 1H NMR and IR. The crystal structures of two derivatives, 2-(2-chlorophenyl)-1H-benzimidazole and 2-(1H-benzimidazol-2-yl)-4-nitrophenol, are presented. A study of the DPPH scavenging activity of these compounds showed that 2-(1H-benzimidazol-2-yl)phenol (2), 2-p-tolyl-1H-benzimidazole (3) and 2-(4-methoxyphenyl)-1H-benzimidazole (7) gave IC50 values 1974, 773 and 800 ”M.               KEY WORDS: Benzimidazole, o-Phenylenediamine, Aldehydes, Base catalysis, DPPH scavenging activity Bull. Chem. Soc. Ethiop. 2018, 32(2), 271-284.DOI: https://dx.doi.org/10.4314/bcse.v32i2.
Hydroxycarbamide versus chronic transfusion for maintenance of transcranial doppler flow velocities in children with sickle cell anaemia-TCD With Transfusions Changing to Hydroxyurea (TWiTCH): a multicentre, open-label, phase 3, non-inferiority trial.
BACKGROUND: For children with sickle cell anaemia and high transcranial doppler (TCD) flow velocities, regular blood transfusions can effectively prevent primary stroke, but must be continued indefinitely. The efficacy of hydroxycarbamide (hydroxyurea) in this setting is unknown; we performed the TWiTCH trial to compare hydroxyurea with standard transfusions.
METHODS: TWiTCH was a multicentre, phase 3, randomised, open-label, non-inferiority trial done at 26 paediatric hospitals and health centres in the USA and Canada. We enrolled children with sickle cell anaemia who were aged 4-16 years and had abnormal TCD flow velocities (â„ 200 cm/s) but no severe vasculopathy. After screening, eligible participants were randomly assigned 1:1 to continue standard transfusions (standard group) or hydroxycarbamide (alternative group). Randomisation was done at a central site, stratified by site with a block size of four, and an adaptive randomisation scheme was used to balance the covariates of baseline age and TCD velocity. The study was open-label, but TCD examinations were read centrally by observers masked to treatment assignment and previous TCD results. Participants assigned to standard treatment continued to receive monthly transfusions to maintain 30% sickle haemoglobin or lower, while those assigned to the alternative treatment started oral hydroxycarbamide at 20 mg/kg per day, which was escalated to each participant\u27s maximum tolerated dose. The treatment period lasted 24 months from randomisation. The primary study endpoint was the 24 month TCD velocity calculated from a general linear mixed model, with the non-inferiority margin set at 15 cm/s. The primary analysis was done in the intention-to-treat population and safety was assessed in all patients who received at least one dose of assigned treatment. This study is registered with ClinicalTrials.gov, number NCT01425307.
FINDINGS: Between Sept 20, 2011, and April 17, 2013, 159 patients consented and enrolled in TWiTCH. 121 participants passed screening and were then randomly assigned to treatment (61 to transfusions and 60 to hydroxycarbamide). At the first scheduled interim analysis, non-inferiority was shown and the sponsor terminated the study. Final model-based TCD velocities were 143 cm/s (95% CI 140-146) in children who received standard transfusions and 138 cm/s (135-142) in those who received hydroxycarbamide, with a difference of 4·54 (0·10-8·98). Non-inferiority (p=8·82âĂâ10(-16)) and post-hoc superiority (p=0·023) were met. Of 29 new neurological events adjudicated centrally by masked reviewers, no strokes were identified, but three transient ischaemic attacks occurred in each group. Magnetic resonance brain imaging and angiography (MRI and MRA) at exit showed no new cerebral infarcts in either treatment group, but worsened vasculopathy in one participant who received standard transfusions. 23 severe adverse events in nine (15%) patients were reported for hydroxycarbamide and ten serious adverse events in six (10%) patients were reported for standard transfusions. The most common serious adverse event in both groups was vaso-occlusive pain (11 events in five [8%] patients with hydroxycarbamide and three events in one [2%] patient for transfusions).
INTERPRETATION: For high-risk children with sickle cell anaemia and abnormal TCD velocities who have received at least 1 year of transfusions, and have no MRA-defined severe vasculopathy, hydroxycarbamide treatment can substitute for chronic transfusions to maintain TCD velocities and help to prevent primary stroke.
FUNDING: National Heart, Lung, and Blood Institute, National Institutes of Health
What determines women's participation in collective action? Evidence from a western Ugandan coffee cooperative
Women smallholders face greater constraints than men in accessing capital and commodity markets in Sub-Saharan Africa. Collective action has been promoted to remedy those disadvantages. Using survey data of 421 women members and 210 nonmembers of a coffee producer cooperative in Western Uganda, this study investigates the determinants of women's participation in cooperatives and women's intensity of participation. The results highlight the importance of access to and control over land for women to join the cooperative in the first place. Participation intensity is measured through women's participation in collective coffee marketing and share capital contributions. It is found that duration of membership, access to extension services, more equal intrahousehold power relations, and joint land ownership positively influence women's ability to commit to collective action. These findings demonstrate the embeddedness of collective action in gender relations and the positive value of women's active participation for agricultural-marketing cooperatives
On low-power analog implementations of particle filters for target tracking
We propose a low-power, analog and mixed-mode, implementation of particle filters. Low-power analog implementation of nonlinear functions such as exponential and arctangent functions is done using multiple-input translinear element (MITE) networks. These nonlinear functions are used to calculate the probability densities in the particle filter. A bearings-only tracking problem is simulated to present the proposed low-power implementation of the particle filter algorithm
Seed systems smallholder farmers use
Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts
Auxological changes in UK survivors of childhood acute lymphoblastic leukaemia treated without cranial irradiation
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