Stable control for contaminated aquifer in an uncertain environment

This paper considered contamination of aquifer resulting from petroleum spillage, which is a common phenomenal in the Niger Delta area of Nigeria. We used the model given by Bestman (1987) and assumed that some endogenous variables are built into the system. To achieve a level of desirable state, we expect the state of water and that of petroleum to be as close as possible within some &epsilon - neighbourhood. A method to compute a stable control u (.) that will minimise the cost of achieving this desirable state was considered in this paper. We apply the result to a second order system. Keywords: Stable Control, Aquifer, Petroleum Spillage

On existence of control for a class of uncertain dynamical systems

In this paper we prove the existence of control for input bounded uncertain dynamical system, modeled on Euclidean spaces of dimensions n and m. We apply the Conjugate Gradient Method (C.G.M) in generating algorithms to compute control signals for the class of problem under consideration. Keywords: Control, Uncertain Dynamical Systems, Conjugate Gradient Method

On a numerical algorithm for uncertain system

A numerical method for computing stable control signals for system with bounded input disturbance is developed. The algorithm is an elaboration of the gradient technique and variable metric method for computing control variables in linear and non-linear optimization problems. This method is developed for an integral quadratic problem subject to a dynamic system with input bounded uncertainty

Onset of Hearing Loss, Gender and Self Concept as Determinants of Academic Achievements in English Language of Students with Hearing Disability in Oyo State, Nigeria

Since every class of students with hearing disability is always a heterogeneous one, the need for establishing relationship between some intrinsic factors in these students and their academic achievements becomes very imperative. This study therefore examined the influence of onset of hearing loss, gender and self concept on their academic performance in English language. 100 Senior Secondary School class III students with hearing disability were purposively selected to participate in the study. The study also raised 3 hypotheses to ascertain relationships between onset of hearing loss, gender, and self concept and English language achievement. Instruments such as the self concept scale of the Adolescent Personal Data Inventory, Adapted English Language Test and Audiological Reports were used. Findings showed that postlingually hearing disabled students were superior to their prelingually hearing-disabled colleagues, male students did better than female students and student with high self concept outclassed those with low self concept. It was therefore recommended that teachers and curriculum developers should adequately consider these findings in teaching and curriculum development activities

The Association Between Hypertension in Pregnancy and Preterm Birth with Fetal Growth Restriction in Singleton and Twin Pregnancy: Use of Twin Versus Singleton Charts.

OBJECTIVE: To compare the rates of fetal growth restriction (FGR) in singleton and twin pregnancies using singleton and twin-specific birthweight standards. METHODS: The study included liveborn twin and singleton pregnancies between January 2000 and January 2019. Hypertensive disorders of pregnancy (HDP) included gestational hypertension and pre-eclampsia. The study outcomes were FGR or small-for-gestational-age (SGA) at birth as assessed using singleton and twin reference charts. RESULTS: The analysis included 1473 twin and 62,432 singleton pregnancies. In singleton pregnancies the risk of PTB <34 weeks without HDP (OR 2.82, p < 0.001), delivery ≥34 weeks with HDP (OR 2.38, p < 0.001), and PTB <34 weeks with HDP (OR 13.65, p < 0.001) were significantly higher in the pregnancies complicated by FGR compared to those without. When selective fetal growth restriction (sFGR) was assessed using the singleton standard, the risk of PTB <34 weeks without HDP (OR 1.03, p = 0.872), delivery ≥34 weeks with HDP (OR 1.36, p = 0.160) were similar in the pregnancies complicated by sFGR compared to those without, while the risk of PTB <34 weeks with HDP (OR 2.41, p = 0.025) was significantly higher in the pregnancies complicated by sFGR compared to those without. When sFGR was assessed using the twin-specific chart, the risk of PTB <34 weeks without HDP (OR 3.55, p < 0.001), delivery ≥34 weeks with HDP (OR 3.17, p = 0.004), and PTB <34 weeks with HDP (OR 5.69, p < 0.001) were significantly higher in the pregnancies complicated by sFGR compared to those without. The stronger and more consistent association persisted in the subgroup analyses according to chorionicity. The strength of association in dichorionic twin pregnancies resembles that of the singletons more closely and consistently when the FGR was diagnosed using the twin-specific charts. CONCLUSION: FGR in twin pregnancies has a stronger and more consistent association with HDP and PTB when using twin-specific rather than singleton charts. This study provides further evidence supporting the use of twin-specific charts when assessing fetal growth in twin pregnancies

Soil weight determination for optimal growth and yield performances of pot-grown maize

Root restriction, reduced growth and poor yield due to an insufficient quantity of soil are the major limitations of pot-grown maize (Zea mays L.). Hence, to determine the actual quantity of soil required for optimal growth and yield performances of pot-grown maize, two maize varieties; BR9943 DMR-SR (yellow) and BR9928 DMR-SR (white), were evaluated in pots of 5, 10, 20, 30 and 40 kg of topsoil in a 2 x 4 factorial (r = 4) using complete randomised design at the Institute of Agricultural Research and Training, Ibadan, Nigeria. Data were collected on plant height (PHT), leaf area (LA), cob length (CBT), number of kernels per row (K/R), number of rows per cob (R/C), number of kernels per cob (K/C) and total grain weight (TGW). The results obtained showed that all the evaluated parameters were significantly different at P < 0.05 across the soil weights. Maize planted in 30 kg of soil had the highest LA (774.25 cm2), R/C (15.25), K/C (405.62) and TGW (73.84 g), compared with maize planted in 5 kg and 10 kg soils. Plant height and CBT were highest when 40 kg of soil was used. The maize varieties BR9928 DMR-SR (yellow) and BR9943 DMR-SR (white) were not significantly different across the growth and yield parameters except for LA, where the yellow maize (651.91 cm2) had a substantially higher LA than the white maize variety (588.19 cm2). Based on the results of this study, 30 kg of topsoil is recommended for optimum growth and yield performances of pot grown maize

Acute administration of co-artesiane induces oxidative stress in the testes of adult male Wistar rats

Co-artesiane is an artemether-lumefantrine combination therapy that is used in the treatment of malaria. In this work we studied the toxicological effect of this drug with reference to seminal and biochemical parameters of the male reproductive system of wistar rats. Twenty (20) adult male rats were divided into four groups of five rats per group. Group A was administered a single dose (4 mg/kg/bw) of Co-artesiane, Group B was administered double dose (8 mg/kg/bw) of Co-artesiane and Group C received 10 mg/kg/bw of the drug for a period of 3 days. Group D served as control and received physiologic saline. In each group body weight, testicular weight, sperm count, motility and viability as well as oxidative stress status were assessed by evaluating the activities of reduced glutathione, Glutathione S-transferase, catalase, super oxide dismutase (SOD) and malondialdehyde (MDA). The mean sperm count, motility and viability in rats treated with Co-artesiane were reduced when compared with controls. Biochemical analyses showed increase in the activities of oxidative stress markers in a dose-dependent manner. The results suggest that the graded dose of Co-artesiane® elicit depletion of antioxidant defense system and induced oxidative stress in the rats

Potentials of Mangifera Indica Seed Oil Extract as Bio-preservative Against Termite Attack on Wood

The need for preservation of wood to prolong it serviceable life is necessary and thus developing a new safer ecofriendly preservative is of importance because of the damages caused by the chemical preservatives. This study, therefore, investigates the bio preservative potentials of Mangifera indica seed oil extract against termite attack on Triplochiton scleroxcylon and Terminalia superba wood. The pods of M. indica were collected and dehulled after which the seeds were removed from the pods, sundried, and blended to fine powder. The fine cotyledon was subjected to solvent extraction for oil using a Soxhlet apparatus and N-hexane as the solvent. Data collected was analyzed using simple statistics and analysis of variance at α = 0.05. The wood was dimensioned into 5 x 5 x 30 cm and 200 ml of seed oil was applied to it using a brush. The treated wood was exposed to field termites and the absorption rate and weight loss to termite attack were determined. Data collected were analysed with t-test at α = 0.05. The percentage weight loss of wood samples due to T. scleroxcylon and T. superba were 13.76 and 11.52 % respectively. These values are lower than the mean values obtained for the control (14.84 and 12.44 %). The absorption of seed oil extract by the wood samples differ significantly (P≤0.05). Meanwhile, there was no significant differences (p&gt;0.05) in the weight loss due to termite between treated wood samples but untreated wood samples differ significantly (p≤0.05). The M. indica seed extract can serve as an alternative preservative against termite attack thereby reducing environmental pollution that may arise from the use of conventional chemical preservatives

EFFECT OF GROUNDNUT CAKE AND SOYA BEANS ON ENHANCED CITRIC ACID PRODUCTION FROM PAWPAW AND ORANGE PEEL BY MUTANTS OF ASPERGILLUS NIGER

This present study was concerned with the biosynthesis of citric acid (CA) with mutant strain of Aspergillus niger using pawpaw and orange peel as substrates by solid state fermentation process. The A. niger strain isolated from spoilt orange was identified, screened for CA production on Czapek-Dox Agar and subjected to mutation by ethidium bromide. The effect of carbon sources, nitrogen sources and substrates were also determined.&nbsp; Among the mutant strains, A. niger PJ-02 A120 was found to be the best mutant that produced citric acid (65.00±0.58f) after 48 hours in Vogel’s medium. The effects of carbon sources (sucrose and glucose) on CA production from each substrate (orange and pawpaw peel) using mutant A. niger PJ-02 was determined and sucrose, the best carbon source was combined with two the nitrogen sources (groundnut cake and soyabeans) to determine the most suitable supplement for CA production. Groundnut cake enhances the production of citric acid while soyabeans was inhibitory. Citric acid was further produced in pawpaw peel and orange peel medium containing sucrose (5 %) groundnut cake (2 %), methanol (1.5 %) and the mutant strain. The orange peel substrates yielded 112.07g/kg of CA while 107.17g/kg was recorded for pawpaw peel when fermented for 5 days at 30°C. The Production of citric acid with mutant Aspergillus niger proved better with orange peel than pawpaw peel when optimized with alcohol. &nbsp; &nbsp; &nbsp

Aural Foreign Bodies in Children

Background: Pediatric aural foreign bodies (FB) are relative medical emergencies. Primary care physicians, pediatricians, and otorhinolaryngologists commonly encounter them. Objective: The objective was to carry out a retrospective analysis of pediatric aural FB managed in otorhinolaryngology department of the University of Calabar Teaching Hospital, Nigeria. Materials and Methods: A total of 157 children with aural FB managed at the Department of Otorhinolaryngology, University of Calabar Teaching Hospital, Nigeria, from January 2015 to December 2018 were reviewed with regard to the type of FB, location, in the ear, methods of removal,&nbsp; complications, age, and sex. Results: Of the 157 children, 54.1% were males and 45.9% females. Male: female ratio was 1.2:1. Ninety‑five (60.5%) were below the age of 5 years, 46 (29.3%) were 6–10 years of age, and 16 (10.2%) were in the age group of 11–15 years. The most common objects were beads, papers, and cotton. Most presentations (86%) were within 24 h. Seven patients (4.5%) required surgical removal under general anesthesia. Most of the patients (92.4%) had no complications. Morbidities include bleeding from the ear canal 6 (3.8%), canal abrasions/lacerations 4 (2.5%), and tympanic membrane perforations 2 (1.3%). Conclusion: Aural FBs are common conditions in children in our environment. Most of these can be successfully removed by skillful personnel,&nbsp; adequate immobilization, and proper instrumentation. Pediatricians, family physicians, and other health workers should not hesitate to refer to otorhinolaryngologists, uncooperative/apprehensive children, those with a history of attempted removal by their parents or caregivers, or FB whose contour, composition and position in the canal cannot be fully assessed. Keywords: Aural, children, foreign bodie