477 research outputs found
Dynamic Optimal Control for Multi-chemotherapy Treatment of Dual Listeriosis Infection in Human and Animal Population
Following the rising cases of high hospitalization versa-vise incessant fatality rates and the close affinity of listeriosis with HIV/AIDS infection, which often emanates from food-borne pathogens associated with listeria monocytogenes infection, this present paper seek and formulated as penultimate model, an 8-Dimensional classical mathematical Equations which directly accounted for the biological interplay of dual listeriosis virions with dual set of population (human and animals). The model was studied under multiple chemotherapies (trimethoprim-sulphamethoxazole with a combination of penicillin or ampicillin and/or gentamicin). Using ODEâs, the positivity and boundedness of system solutions was investigated with model presented as an optimal control problem. In the analysis that follows, the study explored classical Pontryaginâs Maximum Principle with which the model optimality control system as well as existence and uniqueness of the control system were established. In correlating the derived model with clinical implications, numerical validity of the model was conducted. Results indicated that under cogent and adherent to specify multiple chemotherapies, maximal recovery of both human and animal infected population was tremendously achieved with consequent rapid decline to near zero infection growth. The study therefore suggests further articulation of more chemotherapies and early application at onset of infection for a visible elimination of listeriosis infection
Mercury accumulation in fishes from tropical aquatic ecosystems in the Niger Delta, Nigeria
Fishes are important biomarkers of trace elements in
aquatic ecosystems, and are used to evaluate the status
of water pollution by mercury in tropical aquatic ecosystems in Nigeria. Common fishes, Chrysichthys nigrodigitatus,Brycinus nurse, Hemichromis fasciatus,
Lutianus ava, Oreochromis nilotica, Pomadasys jubelini,
Stellifer stellifer and Tilapia guineensis were analysed
for Hg accumulation using the cold vapour atomic absorption spectrophotometry technique. The results
showed that Hg concentration in P. jubelini was relatively
the highest, with a mean concentration of 0.063 ± 0.03 mg kgâ1. Other concentration values were 0.044 ± 0.031 mg kgâ1 for O. nilotica, 0.026 ± 0.013 mg kgâ1 for B. nurse, 0.034 ± 0.034 mg kgâ1 for H. fasciatus, 0.023 ± 0.020 mg kgâ1 for C. nigrodigitatus and 0.33 ± 0.016 mg kgâ1 for L. ava. Concentrations of Hg accumulated by the fishes were low and within internationally accepted limit, not likely to cause mercury poisoning. Because of the high Hg accumulating potential of P. jubelini, it is recommended as a biomarker for assessment of Hg toxicity in a tropical aquatic environment
Derived Models for the Prediction of Coleâs and Dip Parameters for Velocity Gradients Determination in Open Natural Channels
Measurement of vertical velocity in open channel hydraulics is a very reasonable exercise that attracts peculiar results in stream flow. Observations were made on set of values obtained from calibration of models on continuous longitudinal stream flow. They showed that, there emanated effects of eddy currents. The exercise is characterized by downward trend in the velocity gradient resulting in a dip. However, at the early stage of flow development, a stage corresponding to the bed region, where little or no flow occurs, there had been what should be referred to as hypothetic zero flow region. There is vertical relationship between flow pattern developing and the position from the bed and free surface. Local scouring is induced around structural elements such as a bridge pier, an abutment at the lower region eddies and adjourning loose embankment areas. Occurrence is as a result of interaction between turbulent flow and sediment particles at the bed. The entrainment of sediment particles from the bed is probabilistic and definitely dependent upon flow characteristics and strongly influenced by instantaneous shear stresses developed along stream movement. The computed values of Cole's and Dip parameters for vertical velocities estimation were 0.77 and 0.78 respectively. For accurate measurement of vertical velocity profiles, a constant (Ś) has been introduced in models for velocity gradient determinationŚ) .) This coefficient has the estimated value of 3.6 - using mathematical iteration methods advanced by Jacobi and Hardy Cross. The proposed models (PIDMWLEL and PIDMWLL) are recommended to be most suitable for predicting velocity profile in open channels, when aspect ratios are greater than five (5) and ten (10). Keywords: Appearance; calibration; channel; flow velocit
Inflation Targeting Framework for Monetary Policy in Nigeria: Issues, Problems And Prospects.
Over the years, Nigeria has adopted different monetary policy regimes with limited or no success. These ranged from exchange rate targeting, direct monetary controls to monetary targeting. The overall objectives of monetary policy have been the maintenance of macroeconomic stability and non-inflationary growth. In line with the global trend, Nigeria navigated towards adoption of Inflation Targeting monetary framework. But recent policy indication shows that the Central Bank of Nigeria (CBN) may have soft-pedaled in the pursuit of full-fledged Inflation Targeting for the country. This paper attempted to critically analyze the basic issues, problems and prospects germane to the adoption of Inflation Targeting as a monetary policy framework for Nigeria. To do this, the paper examined the basic features and performances of inflation targeting countries globally, adduced that Inflation Targeting is not âa cure-all medicineâ and that it may not significantly reduce the real costs of disinflation in Nigeria in terms of a decline in output and an increase in unemployment. For Nigeria, the extent of the success of Inflation Targeting, if and when adopted, will crucially depend on the availability of executive capacity, quality and timely data and the political will and commitment to the success of the programme on the part of monetary authorities. KEY WORDS: Inflation Targeting, Policy consistency, monetary authoritie
Impact of Social Cost Accounting on Corporate Performance of Petroleum Marketing Firms in Nigeria
The main thrust of this study is to examine the impact of social cost on the corporate performance of petroleum marketing firms in Nigeria. Ex post facto research design was adopted, secondary sources of data were collected for analysis of results and interpretation of data. The results indicated that social cost positively influences the corporate performance of petroleum marketing firms in Nigeria. Hence, it was recommended that the federal government should mandate all petroleum marketing companies to capture and disclose all quantitative data relating to corporate social responsibility which would serve as a boost to the company performances vis-a-vis increased employee productivity
The role of prostaglandins in livestock production
Prostaglandins belong to the family of lipid. Soluble unsaturated hydroxyl acid containing twenty carbon (c) atoms and based on the prostanoic acid skeleton. There are two main types of Prostaglandins (PGs), the E and F series each having 3 members E1, E2, E3 and F1Ï, F2Ï, F3Ï. The other PGs are known as secondary PGs and are products of enzymic or chemical dehydrations of PGEs e.g PG+2, PGA2, PGD2 and PGB. Prostaglandins are probably the most important regulators of female productive functions (ovulation, uterine receptivity, Implantation and parturition) and associated with pathologies (pain, fever, and inflammation), apart from sex steroids. Prostaglandins are not stored in tissues but are synthesized and released in response to a given stimulus. Prostaglandins are produced by all nucleated cells of the body and act locally in a paracrine (locally active) or autocrine (acting on the same cell from which it is in a synthesized) fashion. Prostaglandins are therefore regarded as essential mediators of female reproductive processes, hence, this paper seeks to review the role of Prostaglandins which is exploited in livestock production especially oestrus synchronization and induced parturition.KEYWORDS: Prostaglandins, Production, Role, Livestoc
Microbiological assessment of air-conditioners used in Calabar, Nigeria
Background: There is a rising heat level in Nigeria that has been associated with climate change which has a global reach, exposing millions of people to the risk of several health problems. Usually air conditioners are deployed in human dwellings to eradicate heat conditions but may serve as potential reservoirs of infection if not appropriately used and maintained.Aim: This study was aimed to evaluate in-use air conditioners in Calabar, Nigeria for their role in the transmission of microbial infections between April and August, 2021.Methodology: A cross sectional study was conducted to examine 100 air conditionersâ filters and 50 filtered air samples of the same air conditioners in use for potential bacterial and fungal pathogens. Each filter was wiped with sterile cotton wool swab moistened with sterile peptone water, while the filtered air samples were collected by placing the appropriate culture media plates against the air conditioner air stream in use. The culture plates were incubated at 370C for 24-48hours and one Sabouraud Dextrose agar plate at room temperature for 2-7 days. Identification of the isolates was done using standard bacteriological and mycological methods.Results: Comparatively, the filters were more significantly contaminated with bacteria 100 (100.0%) and fungi 73(73.0%), respectively (x2=62.567, P=0.00001) than the filtered air samples 24(48.0%) and 17(34.0%), respectively (x2=21.13, P=0.00001). All (100%) of the 100 air conditioner filter samples studied carried bacteria compared to 73(73.0%) which carried fungi (x2=31.12, P=0.0001). Also, air conditionerâs air stream samples carried insignificantly more bacteria 24 (48.0%) compared to fungi 17(34.0%) (x2=2.0258, P=0.1546). The most frequently encountered bacteria and fungi in the study were Bacillus species (50.8%) and Aspergillus niger (60.0%), respectively. Others were Aspergillus flavus (40.0%), Pseudomonas aeruginosa (20.2%), Staphylococcus aureus (13.7%), Klebsiella pneumoniae (9.7%), and Escherichia coli (5.6%).Conclusion: This study concludes that air conditioners in-use in Calabar can play role in the transmission and spread of air borne infections. Measures should be taken to ensure implementation of the recommended healthy, periodic cleaning and maintenance as well as from microbiological screening of in-use air conditioners
Reducing Urogenital Infections Including HIV in Sub-Saharan Africa - Can Probiotics Be a Viable Paradigm?
Green Corrosion Inhibitors for Mild Steel in H2SO4 Solution: Flavonoids of Gongronema latifolium
The inhibitive properties of flavonoids extracted from Gongronema latifolium (FEGL) and the crude extracts from Gongronema latifolium (EEGL) on the corrosion of mild steel in H2SO4solutions was studied using hydrogen evolution method at 30, 40, 50, and 60oC. The results revealed that the extracts act as good inhibitors for the corrosion of mild steel in 5.0 M H2SO4 solutions. The inhibition efficiencies were found to increase with increase in the extract concentration and decreased with increase in temperature. The order of efficiency was EEGL > FEGL. The experimental data fitted well into the Langmuir adsorption isotherm. Physical adsorption mechanism was proposed for the adsorption of the extracts on the mild steel surface from the data obtained for the activation energies of the inhibited and uninhibited systems. Keywords: Adsorption; Corrosion; Flavonoids; Inhibitor; Mild Stee
Unsafe abortion among secondary school girls in a local authority in South-South Nigeria
Background: Voluntary abortion for social reasons is illegal in Nigeria; however, the practice remains mostly clandestine and unsafe with varying consequences and determinants yet to be studied in all settings.Methods: A descriptive cross-sectional study design was used to assess the prevalence, practice and determinants of termination of pregnancy amongst 119 female Secondary School students in South-South Nigeria.Results: The prevalence of abortion was 57.1%. Most of the students were above 18years (58.8%), Christian (95.8%) and of rural residence (66.4%). While 58.8% had experienced an unwanted pregnancy, 61.4% had used some form of contraceptive with condom being the commonest (39.5%). Most (89.1%) have heard of abortions while 67.6% and 16.2% have had abortions once and twice respectively with the top reasons for abortion being that they were still in school (33.8%), too young (25.9%) and to avoid shame or stigma associated with the pregnancy (11.7%). Dilation and curettage was the predominant method employed (40.2%) mainly by medical doctors (34.1% and pharmacists (35.6%) while 51 (75%) had post-abortal complaints such as pain (41.2%) and bleeding (21.6%). There was a significant association between having an abortion and place of residence (rural more than urban), (p=0.04), being pregnant more than once (p<0.001), mothers` level of education (p=0.03), fathers` level of education (p=0.02) and mothers occupation (p=0.04).Conclusions: The prevalence of abortion is high and complicated by high morbidity rate despite a higher contraceptive prevalence rate whose major determinants were the socio-demographic characteristics of the parents. There is a need for early sex education from parents as this can influence abortion perception and practice in later years
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