Application of optimal control to the epidemiology of malaria

Malaria is a deadly disease transmitted to humans through the bite of infected female mosquitoes. In this paper a deterministic system of differential equations is presented and studied for the transmission of malaria. Then optimal control theory is applied to investigate optimal strategies for controlling the spread of malaria disease using treatment, insecticide treated bed nets and spray of mosquito insecticide as the system control variables. The possible impact of using combinations of the three controls either one at a time or two at a time on the spread of the disease is also examined

Nigeria’s Phosphate and Uranium Mineral Occurrences: Implication for Mineral Investment

The main aim of this paper is to review the occurrences of phosphate and uranium in Nigeria with a view to encourage local and international investors to develop and exploit these deposits. Nigeria is located on latitude 100 North and longitude 80 East surrounded in the north by Niger and Chad and in the east by Cameroun and in the west by Benin Republic. Available data indicated the viability of mineral investment in the Nigerian phosphate and uranium resources. With the current economic reforms and investment incentives in Nigeria, interested investors are highly welcome to take advantage of developing these mineral resources. Keywords: phosphate, uranium, mineral resources, mineral investment, geochemical mappin

Factors Vitiating Against the Effectiveness Of The Nigeria Police In Combating The Criminal Exploitation of Children And Women

It is estimated that each year close to one million persons are trafficked across international borders. Nigeria has been identified as a major source, destination, and transit for the trafficking of persons, particularly women and children. The women are trafficked mostly to Europe and the Middle East, as well as to North America for the purposes of sexual exploitation. Children are trafficked within Africa and other parts of the world for the purposes of adoption, for domestic and agricultural labor, and for sale of human body parts. Efforts by the government of Nigeria (including enacting new laws, strengthening existing laws and other social control mechanisms, and collaborating with other countries) to combat trafficking and the sale of humans have not yielded appreciable results. Several factors (inadequate policing, corruption within the policing system, relative deprivation of freedoms, mounting social injustices, lack of conventional social opportunities, increasing conflicting social values, gender imbalances in the provision of education and economic opportunities, and the breakdown of social institutions) cause this impasse. This study examines the nature, extent, and development of this phenomenon and attempts to delineate the factors vitiating against Nigeria’s law enforcement and government efforts in combating this particularly troubling international crime. Two policies are possible. The short term would introduce mass education about the danger of human trafficking and strengthen the legal instrument and the capability of the law enforcement system to deal with the problem, and the long term would address the social and economic conditions in Nigeria which sustains the phenomenon

Transit, walking and cycling infrastructure and sustainable development in Enugu city, Nigeria.

In a predominantly urban world, people's ability to move within cities is a critical driver of sustainability. The transportation system which constitutes a large percentage of the physical urban environment provides mobility and aid economic sector. However, it contributes to several major environmental pressures including pollution, congestion, accidents, waste accumulation, resources depletion and disruption of nature. While urban population growth and increase in economic activities combine to generate higher demand for transportation services and heighten the problem. How to effectively deal with these imposing threats and simultaneously provide optimal mobility for city dwellers is the backbone of this research. Drawing experiences from developed cities, the study used Achara layout in Enugu as a case study. From observation, surveys and published literature data were collected and analysed qualitatively. The primary data include, physical traffic count, existing road character, traffic infrastructure and demographic statistics. Findings show the extensive sterility of Enugu’s urban infrastructure to motorized traffic and lack of provision for walking and cycling. It recommends strategies for planning and managing the urban environment which recognizes and acknowledged the social, environmental and economic realities. The conclusion demonstrates that cities designed for pedestrians and cyclist are cities designed for people and sustainable development

Pick Your Poison: How Aspartame Causes Anxiety

BLUF: Limit your aspartame consumption! Studies have shown that consecutive aspartame consumption at as little as 7% of the FDA recommended daily intake can cause anxiety symptoms in ~8 days. Not only that, but after 12 weeks of consumption, it was proven that the anxiety symptoms are passed to the offspring two generations later. That means if you have roughly one to two 32 oz Diet Cokes per day, your children and grandchildren will show symptoms of anxiety even if they never consume aspartame themselves. It is important to note that aspartame is in many foods and products labeled as “diet” due to its zero calorie component. Please be aware of this and limit your aspartame consumption! Primary research project for BIOL491/503 Nutrition and Neuroscience with Dr. Diane Darland.https://commons.und.edu/as-showcase/1014/thumbnail.jp

The Performance Characteristics and Economic Evaluation of Weaner Rabbits Fed Varying Levels of Sundried False Yam (Icacina Tricantha) Meal

A seven week feeding trial was conducted to evaluate the growth performance characteristics and economics of production of 15 unsexed weaner rabbits fed varying levels of Sundried false yam (Icacina tricantha) meal. Five treatments diets were formulated with diet 1 containing 100% maize as control, while in diet 2, 3, 4 and 5 Sundried false yam meal replaced the percentage proportion of maize in diet 1 at 25, 50, 75 and 100% inclusion level respectively. Rabbits were randomly assigned to the five treatment diets in a complete randomized designed (CRD) with three replicates of one rabbits each. Performance characteristics revealed that final live weight and weekly feed intake were significantly (P<0.05) influenced with highest value (2.12kg/rabbit and 407.33g/rabbit) recorded from rabbits fed 0% SDFYM comparable to (1.98kg/rabbit and 323.33g/rabbits) recorded in those fed 50% SDFYM. Avearage weekly weight gain was also significantly (P<0.05) influenced with highest value (197.00g/rabbit) from those fed 50% SDFYM. Feed conversion was lowest and best (1.28) from rabbits fed 25% SDFYM. Mortality rate was lowest (3.43%) in rabbits fed 50% SDFYM. Cost and return analysis revealed that total cost of feed consumed was least (378.24 N /rabbits) from those fed 50% SDFYM and highest in control, cost of feed per kg weight gain and total cost of production were lowest (30.50 and 2178.24 N /rabbits) from the rabbits that ate 75% SDFYM and highest in control. Income and net profit were highest (5000 and 1763.36 N /rabbits). It is concluded from this study that Sundried false yam meal is a valuable substitution for maize up to 50% in rabbit diets without any adverse effects on the performance characteristics and economic returns of rabbits

Effects of age and reproductive status on tergal gland secretions in queenless honey bee workers, Apis mellifera scutellata and A. m. capensis

Secretions from tergal glands are part of a queen’s pheromonal control of worker reproduction in honey bees. However, in queenless honey bee colonies, workers compete to gain pheromonal, and hence reproductive dominance, over nestmates with ontogenetic changes in their glandular secretions that affect the behavioral or physiological responses of other individuals. Using gas chromatography/mass spectrometry, we investigated for the first time the age-dependent changes in tergal gland secretions of queenless workers of the clonal lineage of Apis mellifera capensis and workers of A. m. scutellata. The reproductive status of honey bee workers was determined by recording the presence of spermathecae and the level of ovarian activation. The tergal gland chemicals identified in both A. m. scutellata workers and A. m. capensis clone workers were oleic acid, n-tricosene, n-pentacosene, and n-heptacosene, with three additional compounds, palmitic acid, n-heneicosene, and n-nonacosene, in A. m. capensis clones.We report ethyl esters as new compounds from honey bee worker tergal gland profiles; these compounds increased in amount with age. All A. m. capensis clone workers dissected had spermathecae and showed ovarian activation from day 4, while ovarian activation only started on day 7 for A. m. scutellata workers that had no spermathecae. Tergal gland secretions were present in higher quantities in bees with activated, rather than inactive ovaries. This suggests that tergal gland secretions from reproductive workers could act as releaser and primer pheromones in synergy with other glandular compounds to achieve pheromonal and reproductive dominance.A University of Pretoria postgraduate research bursary (Okosun), by the Competitive Programme for Rated Researcher of the National Research Foundation (NRF) South Africa (Pirk), incentive funding of the NRF (Crewe, Pirk), and the DST/NRF SARChI Chair in Mathematical Models and Methods in Bioengineering and Biosciences (M3B2) at the University of Pretoria (Yusuf).http://link.springer.com/journal/108862016-10-31hb2016Zoology and Entomolog

Glandular sources of pheromones used to control host workers (Apis mellifera scutellata) by socially parasitic workers of Apis mellifera capensis

Pheromonal control by the honey bee queen is achieved through the use of secretions from diverse glandular sources, but the use of pheromones from a variety of glandular sources by reproductively dominant workers, has not previously been explored. Using the social parasite, Apis mellifera capensis clonal worker we studied the diversity of glandular sources used for pheromonal control of reproductively subordinate A. m. scutellata workers. To determine whether pheromones from different glandular sources are used by reproductively active workers to achieve dominance and evaluate the degree of pheromonal competition between workers of the two sub-species, we housed groups of workers of the two sub-species together in cages and analysed mandibular and tergal gland secretions as well as, ovarian activation status of each worker after 21 days. The results showed that A. m. capensis invasive clones used both mandibular and tergal gland secretions to achieve reproductive dominance and suppress ovarian activation in their A. m. scutellata host workers. The reproductively dominant workers (false queens) produced more queen-like pheromones and inhibited ovarian activation in subordinate A. m. scutellata workers. These results show that tergal gland pheromones working in synergy with pheromones from other glands allow individual workers (false queens) to establish reproductive dominance within these social groups and to act in a manner similar to that of queens. Thus suggesting that, the evolution of reproductively dominant individuals (queens or false queens) and subordinate individuals (workers) in social insects like the honey bee is the result of a complex interplay of pheromonal signals from different exocrine glands.The Competitive Programme for Rated Researchers of the South African National Research Foundation (NRF) (CWWP), incentive funding of the NRF (RMC, CWWP), the DST/NRF Research Career Advancement Fellowship/SARChI Chair in Mathematical Models and Methods in Bioengineering and Biosciences (M3B2) at the University of Pretoria (AAY) and a University of Pretoria postgraduate research bursary to OOO.http://:www.elsevier.com/locate/jinsphys2018-10-30hj2018Zoology and Entomolog

Tergal gland components of reproductively dominant honey bee workers have both primer and releaser effects on subordinate workers

The primer and releaser effects of dominant honey bee workers’ tergal gland pheromones are not known under queenless conditions. The Cape honey bee, Apis mellifera capensis, is the ideal model to investigate such question since workers normally reproductively dominate workers of all other subspecies. We determined the effects that short- and long-term exposure to pheromone blends from dominant A. m. capensis workers had on subordinate workers of A. m. scutellata. Three putative pheromonal blends, 1 (palmitic acid, oleic acid, n-heneicosene and n-tricosene), 2 (ethyl palmitate, ethyl oleate and ethyl stearate) and 3 (mixture of blends 1 + 2), were tested. All the three putative pheromonal blends elicited releaser effects in the form of retinue formation and primer effects by suppressing ovarian activation in workers. The resultant effects indicated that these pheromonal blends appear to play a role in establishing dominance among workers and hence regulating opportunities to reproduce.The National Research Foundation (NRF) of South Africa’s Competitive Programme for rated researchers and incentive funding to CWWP, RMC and AAY (grant numbers 90579, 111683, 103710 and 109380), NRF Research Career Advance-ment Fellowship (grant number 91419) to AAY, NRF Scarce Skills Postdoctoral Fellowship to OOO (Grant number 108019) and University of Pretoria, South Africa.http://link.springer.com/journal/13592hj2020Zoology and Entomolog