QUEUES WITH SERVER UTILIZATION OF ONE

In most queueing systems of type GI/G/1, the stability condition requires that the server utilization be strictly less than 1. The standard exception is a D/D/1 system in which stability still holds for server utilization equal to 1. This paper presents other cases when server utilization can equal 1, and discusses their characteristics

Is there any economics in smallholder cocoyam production? Evidence from the forest agro-ecological zone of Ghana

Abstract Background Cocoyam is an important food security crop in Ghana because it stores better than all other root and tuber crops. Despite its socio-economic relevance, production has declined persistently since the last decade. This study attempts to examine the profitability of cocoyam production to smallholders in Ghana by estimating the returns on critical production resources. Using a multi-stage sampling technique, 150 cocoyam producers were randomly sampled across three major producing regions in Ghana. Results Empirical results reveal that cocoyam production is generally not profitable given the present cost of capital in Ghana, suggesting why farmers are shifting from its production. A disaggregated analysis reveals that producers in Fanteakwa district have a competitive advantage over their counterparts in Asante Akyem South and Asunafo North districts in terms of relative profitability owing to higher yield and better produce price at terminal markets. Gross margin, net profit, and returns on assets, land as well as unpaid labour and management significantly varied across districts. Producing cocoyam on sole crop basis was found to significantly return higher than the predominant intercropping culture of production. Apart from production cost, gross margins, net income and returns to critical production factors under the mono-cropping system were found to be significantly higher, at 5% significance level, compared to the intercropping system. Conclusion The study concludes that smallholder cocoyam production is presently not profitable, and hence, production scales have reduced to subsistence levels. Due to higher yield and better produce prices, Fanteakwa farmers have a competitive advantage over other producing districts. Production under the mono-cropping system is relatively profitable than under the intercropping system. However, the financial leverage of cocoyam production could be enhanced via policy alternatives directed at ensuring farmers’ access to and intensification of productive inputs

Improving Soya Bean Productivity for Poverty Alleviation and Food Security in Upper West Region of Ghana: A Resource Use Efficiency Analysis

Soya bean is an important economic crop for smallholder farming systems in Upper West Region of Ghana. In spite of the introduction of modern and improved soya bean production technologies in Ghana, the productivity of the crop in the region is still low. Given that inefficient use of resources is a potential course of low yields, this study analyses the resource use efficiency of soya bean production. Using cross-sectional data collected from 271 soya bean farmers from the Upper West Region of Ghana, the study employed the Stochastic Frontier Translog Production Function as well as the ratio of Marginal Value Product to Marginal Factor Cost to understand the resource use efficiency of soya bean farmers in the region. The empirical results showed that the estimated coefficients of soya bean seeds, labor and farm size were significant and positively related to soya bean output even though fertilizer input was surprisingly significantly and negatively related to the output of soya bean. Also, resources employed in soya bean production were found not to be efficiently utilized as they were underutilized, indicating that yield and profit could be improved with optimal use of production inputs. Finally, the paper revealed that access to soya bean threshers is the most important constraint faced by farmers in the region. For the region’s soya bean yield to be improved, government and development organizations should assist soya bean farmers by removing major bottlenecks to acquisition of resources required for the production and postharvest handling of the crop

Farmers’ perception about quality of planted seed yam and their preferences for certified seed yam in Ghana

The study examined the effect of farmers’ perception about the quality of seed yam typically used for cultivation on their preferences for certified seed yam. Heckman’s sample selectivity probit model was applied on survey data collected from 380 yam farmers. The study found that farmers generally agree that the use of certified seed yam would help to improve yield because of minimum to no disease/pest infestation. Farmers expressed their willingness to purchase certified seed yam if the price is about 26% higher than those supplied from the informal system in as much as the quality can be assured. The study found that farmer educational level, experience, access to extension services and household incomes were factors influencing farmers’ perception about quality of seed yam cultivated. Variables such as age, educational level and income were also found to be factors that influence farmers’ preference for certified seed yam. The results were similar for both Pona and other white yam varieties. The study recommends promotion of farmer education through increased access to extension services on seed quality assessment together with other agronomic practices including farmer field schools, to help improve their ability to assess the quality of seed yam obtained from other sources as well as increase their preference for certified seed yam

A latent class modelling approach to evaluating farmers’ preferences for pona seed yam certification systems and their willingness to pay in Ghana

The study employed choice experiment and latent class model to assess farmers’ preferences for seed yam certification system and their willingness to pay for certified seed yam in selected yam producing Districts in Ghana. A total of 9120 choice experiments were conducted to elicit data from 380 yam farmers. The study identified three classes/ market segments of farmers regarding preferences for Pona seed yam. The results show that farmers have more utility towards fully certified seed yam and are willing to pay GH¢719.60 (US$189.4) for a bunch (100 tubers weighing about 45kg) of fully certified seed yam. However, farmers were found to have high utility towards medium-sized Pona seed yam and are willing to pay a premium of GHC¢12.5 (US$3.3) for this attribute. The study has demonstrated high potential for the commercialization of seed yam production in Ghana through a formal seed yam certification system

An Immune Basis for Malaria Protection by the Sickle Cell Trait

BACKGROUND: Malaria resistance by the sickle cell trait (genotype HbAS) has served as the prime example of genetic selection for over half a century. Nevertheless, the mechanism of this resistance remains the subject of considerable debate. While it probably involves innate factors such as the reduced ability of Plasmodium falciparum parasites to grow and multiply in HbAS erythrocytes, recent observations suggest that it might also involve the accelerated acquisition of malaria-specific immunity. METHODS AND FINDINGS: We studied the age-specific protection afforded by HbAS against clinical malaria in children living on the coast of Kenya. We found that protection increased with age from only 20% in the first 2 y of life to a maximum of 56% by the age of 10 y, returning thereafter to 30% in participants greater than 10 y old. CONCLUSIONS: Our observations suggest that malaria protection by HbAS involves the enhancement of not only innate but also of acquired immunity to the parasite. A better understanding of the underlying mechanisms might yield important insights into both these processes

Utilising cumulative antibiogram data to enhance antibiotic stewardship capacity in the Cape Coast Teaching Hospital, Ghana

Background: Antimicrobial resistance (AMR) is a major public health challenge with its impact felt disproportionately in Western Sub-Saharan Africa. Routine microbiology investigations serve as a rich source of AMR monitoring and surveillance data. Geographical variations in susceptibility patterns necessitate regional and institutional tracking of resistance patterns to aid in tailored Antimicrobial Stewardship (AMS) interventions to improve antibiotic use in such settings. This study focused on developing a cumulative antibiogram of bacterial isolates from clinical samples at the Cape Coast Teaching Hospital (CCTH). This was ultimately to improve AMS by guiding empiric therapy. Methods: A hospital-based longitudinal study involving standard microbiological procedures was conducted from 1st January to 31st December 2020. Isolates from routine diagnostic aerobic cultures were identified by colony morphology, Gram staining, and conventional biochemical tests. Isolates were subjected to antibiotic susceptibility testing using Kirby-Bauer disc diffusion. Inhibitory zone diameters were interpreted per the Clinical and Laboratory Standards Institute guidelines and were entered and analysed on the WHONET software using the “first isolate only” principle. Results: Overall, low to moderate susceptibility was observed in most pathogen-antibiotic combinations analysed in the study. Amikacin showed the highest susceptibility (86%, n = 537/626) against all Gram-negatives with ampicillin exhibiting the lowest (6%, n = 27/480). Among the Gram-positives, the highest susceptibilities were exhibited by gentamicin (78%, n = 124/159), with clindamycin having the lowest susceptibility (27%, n = 41/154). Among the Gram-negatives, 66% (n = 426/648) of the isolates were identified phenotypically as potential extended-spectrum beta-lactamase producers. Multiple multidrug-resistant isolates were also identified among both Gram-positive and Gram-negative isolates. Low to moderate susceptibility was found against first- and second-line antibiotics recommended in the National standard treatment guidelines (NSTG). Laboratory quality management deficiencies and a turnaround time of 3.4 days were the major AMS barriers identified. Conclusions: Low to moderate susceptibilities coupled with high rates of phenotypic resistance warrant tailoring NSTGs to fit local contexts within CCTH even after considering the biases in these results. The cumulative antibiogram proved a key AMS programme component after its communication to clinicians and subsequent monitoring of its influence on prescribing indicators. This should be adopted to enhance such programmes across the country

Antimicrobial stewardship capacity and antibiotic utilisation practices in the Cape Coast Teaching Hospital, Ghana: A point prevalence survey study

Introduction: Antimicrobial resistance (AMR) is a global threat that necessitates coordinated strategies to improve antibiotic prescribing and reduce AMR. A key activity is ascertaining current prescribing patterns in hospitals to identify targets for quality improvement programmes. Methods: The World Health Organisation point prevalence survey methodology was used to assess antibiotic prescribing in the Cape Coast Teaching Hospital. All core variables identified by the methodology were recorded. Results: A total of 78.8% (82/104) patients were prescribed at least one antibiotic, with the majority from adult surgical wards (52.14%). Significantly longer hospital stays were associated with patients who underwent surgery (p = 0.0423). “Access” antibiotics dominated total prescriptions (63.8%, 132/207) with ceftriaxone, cefuroxime, and ciprofloxacin being the most prescribed “Watch” antibiotics. The most common indications were for medical prophylaxis (59.8%, 49/82) and surgical prophylaxis (46.3%, 38/82). Over one-third of surgical prophylaxis (34.2%, 13/38) indications extended beyond one day. There was moderate documentation of reasons for antibiotic treatment in patient notes (65.9%, 54/82), and targeted therapy after samples were taken for antimicrobial susceptibility testing (41.7%, 10/24). Guideline compliance was low (25%) where available. Conclusions: There was high use of antibiotics within the hospital which needs addressing. Identified quality targets include developing surgical prophylaxis guidelines, reviewing “Watch” antibiotic prescribing, and assessing antibiotic durations for patients on two or more antibiotics. Organizational-level deficiencies were also identified that need addressing to help instigate ASPs. These can be addressed by developing local prescribing protocols and antibiotic stewardship policies in this hospital and wider in Ghana and across Africa

Antimicrobial stewardship capacity and antibiotic utilisation practices in the Cape Coast Teaching Hospital, Ghana : a point prevalence survey study

Introduction Antimicrobial resistance (AMR) is a global threat that necessitates coordinated strategies to improve antibiotic prescribing and reduce AMR. A key activity is ascertaining current prescribing patterns in hospitals to identify targets for quality improvement programmes. Methods The World Health Organisation point prevalence survey methodology was used to assess antibiotic prescribing in the Cape Coast Teaching Hospital. All core variables identified by the methodology were recorded. Results A total of 78.8% (82/104) patients were prescribed at least one antibiotic, with the majority from adult surgical wards (52.14%). Significantly longer hospital stays were associated with patients who underwent surgery (p = 0.0423). “Access” antibiotics dominated total prescriptions (63.8%, 132/207) with ceftriaxone, cefuroxime, and ciprofloxacin being the most prescribed “Watch” antibiotics. The most common indications were for medical prophylaxis (59.8%, 49/82) and surgical prophylaxis (46.3%, 38/82). Over one-third of surgical prophylaxis (34.2%, 13/38) indications extended beyond one day. There was moderate documentation of reasons for antibiotic treatment in patient notes (65.9%, 54/82), and targeted therapy after samples were taken for antimicrobial susceptibility testing (41.7%, 10/24). Guideline compliance was low (25%) where available. Conclusions There was high use of antibiotics within the hospital which needs addressing. Identified quality targets include developing surgical prophylaxis guidelines, reviewing “Watch” antibiotic prescribing, and assessing antibiotic durations for patients on two or more antibiotics. Organizational-level deficiencies were also identified that need addressing to help instigate ASPs. These can be addressed by developing local prescribing protocols and antibiotic stewardship policies in this hospital and wider in Ghana and across Africa

Mapping Obesogenic food environments in South Africa and Ghana: Correlations and contradictions

In sub-Saharan Africa, urbanisation and food systems change contribute to rapid dietary transitions promoting obesity. It is unclear to what extent these changes are mediated by neighbourhood food environments or other factors. This paper correlates neighbourhood food provision with household consumption and poverty in Khayelitsha, South Africa and Ahodwo, Ghana. Georeferenced survey data of food consumption and provision were classified by obesity risk and protection. Outlets were mapped, and density and distribution correlated with risk classe