ON THE COMBINATORIAL PROPERTIES OF NILPOTENT AND IDEMPOTENT CONJUGACY CLASSES OF THE INJECTIVE ORDER-DECREASING TRANSFORMATION SEMIGROUP

The elements of the injective order-decreasing transformation semigroup using path structure (Circuits and Proper paths) introduced by Stephen Lipscomb is presented. The elements were grouped according to their conjugacy class, the nilpotents and the idempotents were identified and the nilpotent and idempotent conjugacy class chain decompositions studied. Some observations were made and their order enumerated. Formulae were found for their order and combinatorial propertie

Differentials in Adoption of Improved Fish Farming Technologies among Farmers in Imo State, Nigeria: A Gender Analyses

Women are key players in fish farming and their participation is critical to achieving food security and economic well-being. The study was designed with the purpose to address the gender gap in the adoption of fish farming technologies and output in Imo State, Nigeria. The study described the socio economic characteristics of fish farmers, investigated level and determinants of adoption of fish farming among the respondents in the study area. Multistage and purposive sampling techniques were used for the selection of Sixty (60) respondents interviewed for the study. Descriptive statistics and Tobit regression procedure were used to analyze the data obtained. Results indicate that 43.3% and 30.0% of male and female fish farmers respectively, were within the age group of 41-50 years. Majority (72.2%) of the male fish farmers inherited their land, while 80% of female fish farmers had theirs through lease. About 70% of the males had 1-2 number of extension contacts, and 50.0% of the female farmers also. Results showed that male fish farmers dominated in the adoption of 5 improved fish farming technologies compared to their female (3) counterparts. Stocking density had the highest mean level of adoption (3.97) for the male fish farmers, while, feed formulation had the highest (3.67) for the female fish farmers. Important factors influencing the probability and intensity of adoption of improved fish farming technologies among the farmers include; education, extension, farm size, access to credit, membership of cooperatives, and environmental attribute. The results therefore, call for the need for policies aimed at free and affordable education, especially targeted at women to enable them access and process information on improved fish farming technologies. There is also need to increase the number of extension visits to enhance gender balance in adoption of fish farming technologies in the study area. Fish farmers should be encouraged to belong to or form cooperatives/groups to enable them ease of access to inputs and resources, especially credit and information that will enhance adoption

Prevalence of Cardiovascular Risk Factors in the Middle-Aged and Elderly Population of a Nigerian Rural Community

Cardiovascular diseases (CVDs) causes of worldwide preventable morbidity and mortality. CVDs are a leading cause of mortality and morbidity in developing countries, and rates are expected to rise over the next few decades. The prevalence of CVD risk factors is dramatically increasing in low-and middle-income African countries, particularly in urban areas. We carried out a cross-sectional population-based survey in Imezi-Owa, a rural community in South East Nigeria to estimate the prevalence of major cardiovascular risk factors in both men and women aged 40–70 years. A total of 858 individuals made up of 247 (28.8%) males and 611 (71.2%) females were recruited. The mean age of the subjects was 59.8 ± 9.9 years. The prevalence of the different cardiovascular risk factors among the 858 subjects was as follows: hypertension 398 (46.4%) subjects, generalized obesity as determined by BMI 257 (30%) subjects, abdominal obesity 266 (31%) subjects, dysglycaemia 38 (4.4%) subjects and hypercholesterolaemia 32 (3.7%) subjects. Prevalence of hypertension and dysglycaemia was higher in men while the others were higher in women. Only hypertension (P = .117) and hypercholesterolaemia (P = .183) did not reveal any significant association with gender. Prevalence of CVD risk factors was highest in subjects aged 65 to 70 years

Pattern of Blood Pressure Indices among the Residents of a Rural Community in South East Nigeria

Cardiovascular diseases (CVDs) are the main causes of death in industrialized countries, and are significant causes of morbidity and mortality in sub-Saharan Africa. Hypertension is the most common cardiovascular disease in Nigerians, and the risk of CVD associated with hypertension is independent of other risk factors. Despite the high level of awareness of its presence in the developed countries, the level of control is still poor. CVDs tend to be commoner in urban settlements, and it has been hypothesized that rural sub-Saharan Africa is at an early stage of epidemiological transition from communicable to non-communicable diseases (NCD) because of the gradual adoption of unhealthy lifestyles. This study aimed at describing the pattern of blood pressure indices among the hypertensive residents of a rural community in South East Nigeria. A total of 858 individuals comprising 247 males and 611 females took part in the study. 46.4% of the subjects had hypertension. Hypertension was commoner in the males (50.2% vs. 44.8%) (χ2(1) = 1.484; P = 0.223). The males were significantly older and heavier than the females while the females had higher mean values of BMI and WC. The prevalence of hypertension is becoming alarmingly high in the rural communities of sub-Saharan Africa

Modelling control of Schistosoma haematobium infection: predictions of the long-term impact of mass drug administration in Africa.

BACKGROUND: Effective control of schistosomiasis remains a challenging problem for endemic areas of the world. Given knowledge of the biology of transmission and past experience with mass drug administration (MDA) programs, it is important to critically evaluate the likelihood that MDA programs will achieve substantial reductions in Schistosoma prevalence. In implementing the World Health Organization Roadmap for Neglected Tropical Diseases it would useful for policymaking to model projections of the status of Schistosoma control in MDA-treated areas in the next 5-10 years. METHODS: Calibrated mathematical models were used to project the effects of different frequency and coverage of MDA for schistosomiasis haematobia control in present-day endemic communities, taking into account uncertainties of parasite biology and input data. The modeling approach in this analysis was the Stratified Worm Burden model developed in our earlier works, calibrated using data from longitudinal S. haematobium control trials in Kenya. RESULTS: Model-based simulations of MDA control in typical low-risk and higher-risk communities indicated that infection prevalence can be substantially reduced within 10 years only when there is a high degree of community participation (>70 %) with at least annual MDA. Significant risk for re-emergence of infection remains if MDA is suspended. CONCLUSIONS: In a stable (stationary) ecosystem, Schistosoma reproduction and transmission are sufficiently robust that the process of human infection continues, even under pressure from aggressive MDA. MDA alone is unlikely to interrupt transmission, and once mass treatment is suspended, the prevalence of human infection is likely to rebound to pre-control levels over a period of 25-30 years. MDA success in achieving very low levels of infection prevalence is highly dependent on treatment coverage and frequency within the local human population, and requires that both adults and children be included in drug delivery coverage. Ultimately, supplemental snail control and significant improvements in sanitation will be required to achieve full control of schistosomiasis by elimination of ongoing Schistosoma transmission

Economically optimal timing for crop disease control under uncertainty: an options approach

Severe large-scale disease and pest infestations in agricultural regions can cause significant economic damage. Understanding if and when disease control measures should be taken in the presence of risk and uncertainty is a key issue. We develop a framework to examine the economically optimal timing of treatment. The decision to treat should only be undertaken when the benefits exceed the costs by a certain amount and not if they are merely equal to or greater than the costs as standard net-present-value (NPV) analysis suggests. This criterion leads to a reduction in fungicide use. We investigate the effect of the model for disease progress on the value required for immediate treatment by comparing two standard models for disease increase (exponential and logistic growth). Analyses show that the threshold value of benefits required for immediate release of treatment varies significantly with the relative duration of the agricultural season, the intrinsic rate of increase of the disease and the level of uncertainty in disease progression. In comparing the performance of the delay strategy introduced here with the conventional NPV approach, we show how the degree of uncertainty affects the benefits of delaying control