Finite difference spectral collocation schemes for the solutions of boundary value problems.

This article introduces novel numerical approaches utilizing both standard and nonstandard finite difference methods to solve one-dimensional Bratu's problems. Using the quasilinearization technique, the original problem is converted into a sequence of linear problems. Chebyshev polynomials are employed to approximate the second derivative of the function y(x), after which Sumudu transform is applied to obtain a new form of trial function. The obtained trial function is then substituted into a linearized and discretized Bratu's equations. We discuss the convergence of the schemes and compare the numerical outcomes to those derived using other relevant methods. We further modify one of the new schemes and apply it to solve boundary value problem with associated Robin conditions. The results show that the proposed schemes yield accurate approximations to the solutions of the problems considered.

Effect of litter management systems on incidence and severity of footpad dermatitis among broilers at finisher stage.

Pododermatitis, or footpad dermatitis (FPD), is a welfare concern affecting broiler chickens globally. In the humid tropics, where high temperatures and humidity prevail, the impact of pododermatitis on broiler performance characteristics and behavior becomes even more significant hence this investigation. One hundred and eighty male broilers were used for this experiment out of 200 birds initially procured at day old. They were brooded and reared on deep litter and at 21 days of age, they were randomly allotted to the experimental unit. There were three treatments each with three replicates in a completely randomized design. The three litter management systems constituted the treatment groups. In the first treatment (t-A), litter materials were changed on a weekly basis and replaced with fresh ones while in the second treatment (t-B), the litter materials were turned or raked once a week, and in the third treatment (t-C), the litter materials were left untouched. The litter material used across all treatments was wood shavings and t-C served as control. The experimental birds were fed ad libitum during the trial. Data on daily feed intake, incidence and severity of paw lesions, and weekly body weights were taken while the experiment lasted 35 days. Test of mobility and aggression were carried out on the birds from each group on the last day of the experiment. The moisture content and pH of litter materials of each replicate were taken weekly from day 21 till the end of the experiment. Data were later subjected to analysis of variance statistically. The results revealed that broilers on t-A performed better (P < 0.05) than those on t-B and t-C for feed intake, live weight, weight gain, and feed utilization. However, FPD was pronounced among broilers on t-C and much more severe. A positive correlation was observed between the values of litter moisture content, litter pH, and incidence and severity of FPD. Birds on t-C were dull in appearance and inactive. In conclusion, FPD has a detrimental impact on the performance characteristics and behavior of broiler chickens in the humid tropics. However, the severity depends on the management system adopted. By adopting appropriate management practices such as weekly replacement of litter with fresh ones, it is possible to alleviate the negative consequences of FPD, improve broiler welfare, and enhance the sustainability of the poultry industry in these regions.

Association mapping in multiple yam species (Dioscorea spp.) of quantitative trait loci for yield-related traits.

BACKGROUND: Yam (Dioscorea spp.) is multiple species with various ploidy level and considered as cash crop in many producing areas. Selection based phenotyping for yield and its related traits such as mosaic virus and anthracnose diseases resistance and plant vigor in multiple species of yam is lengthy however, marker information has proven to enhance selection efficiency. METHODOLOGY: In this study, a panel of 182 yam accessions distributed across six yam species were assessed for diversity and marker-traits association study using SNP markers generated from Diversity Array Technology platform. For the traits association analysis, the relation matrix alongside the population structure were used as co-factor to avoid false discovery using Multiple random Mixed Linear Model (MrMLM) followed by gene annotation. RESULTS: Accessions performance were significantly different (p < 0.001) across all the traits with high broad-sense heritability (H2). Phenotypic and genotypic correlations showed positive relationships between yield and vigor but negative for yield and yam mosaic disease severity. Population structure revealed k = 6 as optimal clusters-based species. A total of 22 SNP markers were identified to be associated with yield, vigor, mosaic and anthracnose diseases resistance. Gene annotation for the significant SNP loci identified some putative genes associated with primary metabolism, pest and resistance to anthracnose disease, maintenance of NADPH in biosynthetic reaction especially those involving nitro-oxidative stress for resistance to mosaic virus, and seed development, photosynthesis, nutrition use efficiency, stress tolerance, vegetative and reproductive development for tuber yield. CONCLUSION: This study provides valuable insights into the genetic control of plant vigor, anthracnose, mosaic virus resistance, and tuber yield in yam and thus, opens an avenue for developing additional genomic resources for markers-assisted selection focusing on multiple yam species.

A hybrid collocation method for solving highly nonlinear boundary value problems.

In this article, a hybrid collocation method for solving highly nonlinear boundary value problems is presented. This hybrid method combines Chebyshev collocation method with Laplace and differential transform methods to obtain approximate solutions of some highly nonlinear two-point boundary value problems of ordinary differential equations. The efficiency of the method is demonstrated by applying it to ordinary differential equations modelling Darcy-Brinkman-Forchheimer momentum problem, laminar viscous flow problem in a semi-porous channel subject to transverse magnetic field, fin problem with a temperature-dependent thermal conductivity, transformed equations modelling two-dimensional viscous flow problem in a rectangular domain bounded by two moving porous walls and two-dimensional constant speed squeezing flow of a viscous fluid between two approaching parallel plates. The results obtained are compared with the existing methods and the results show that the new method is quite reasonable, accurate and efficient.

Contamination, sources and risk assessments of metals in media from Anka artisanal gold mining area, Northwest Nigeria.

Mining is a major human activity that has contributed significantly to high degree of environmental and human health degradation. This study was done to uncover the degree of contamination and risks associated with metals in environmental media collected from Anka area, Northwest Nigeria. A total of eighty-two (82) samples which include 42 soils, 22 stream sediments, 13 tailings and 5 plants were collected. Media were air-dried, pulverized and sieved to collect fine particles. They were digested and analyzed for toxic metal contents using High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometer (HPLC-ICPMS). Metals analyzed include As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Zn and Fe. From the results, degree of contamination in samples were obtained using pollution indices, while ecological and health risks were calculated using acceptable risk indices. Average concentrations of metals in the soils were: As: 0.64 µg/g; Cr: 42.55 µg/g; Pb: 131.76 µg/g; Hg: 0.85 µg/g while in sediments, the average concentration were As: 15.46 µg/g; Cr: 111.82 µg/g; Pb: 2234.02 µg/g; Hg: 2.12 µg/g. In tailings, the mean concentration were As: 4.79 µg/g; Cr: 96.95 µg/g; Pb: 2802.56 µg/g; Hg: 1.25 µg/g. Metals in plants are above acceptable limits. Metals in the media are both from geogenic and mining activities, and they pose high ecological risks. High carcinogenic (>10-4) and non-carcinogenic (>1) health risks are associated with metals in media from this area. Further epidemiological studies should be carried to know the extent of occurrence of diseases associated with mining in the area.

Correlation of sonographic inferior vena cava and aorta diameter ratio with dehydration in Nigerian children.

BACKGROUND: Accurate assessment of the degree of dehydration is essential in the management and fluid therapy of dehydrated children. The invasiveness of central venous pressure limits its routine clinical use. Fortunately, some studies have suggested that ultrasonographic measurement of inferior vena cava (IVC) diameter: aorta diameter ratio (IADR) is an objective method of assessing intravascular volume. OBJECTIVES: To determine the clinical usefulness of ultrasound measurement of IADR in assessment of children with dehydration. METHODOLOGY: This was a cross-sectional study which compared dehydrated children to age- and sex-matched euvolemic healthy children as controls. The maximum anteroposterior diameter of the abdominal aorta (at peak systole) and maximum IVC diameter (in expiration) were measured. RESULTS: A total of 120 subjects and 120 controls were evaluated. The mean age was 21.73 ± 20.89 months for subjects and 21.19 ± 22.13 months for control. The mean IADR for children with mild, moderate, and severe dehydration was 0.75 ± 0.07, 0.55 ± 0.07, and 0.33 ± 0.05, respectively. The mean IADR for controls was 0.99 ± 0.06. IADR had an inverse relationship with the degree of dehydration in the subjects. A cut-off point of 0.86, with a sensitivity and specificity of 96.7% in predicting dehydration, was derived, with the sensitivity and specificity increasing with increasing level of dehydration. CONCLUSION: IADR is sensitive and specific for assessing moderate and severe dehydration in Nigerian children.

Multiple perturbed collocation tau method for solving nonlinear integro-differential equations

ABSTRACT: The purpose of the study was to investigate the numerical solution of non-linear Fredholm and Volterra integro-differential equations by the proposed method called Multiple Perturbed Collocation Tau Method (MPCTM). We assumed a perturbed approximate solution in terms of Chebyshev polynomial basis function and then determined the derivatives of the perturbed approximate solution which are then substituted into the special classes of the problems considered. Thus, resulting into n-folds integration, the resulting equation is then collocated at equally spaced interior points and the unknown constants in the approximate solution are then obtained by Newton's method which are then substituted back into the approximate solution.Illustrative examples are given to demonstrate the efficiency, computational cost and accuracy of the method. The results obtained with some numerical examples are compared favorable with some existing numerical methods in literature and with the exact solutions where they are known in closed form

Mycosis fungoides: case report and literature review.

Mycosis fungoides (MF), also known as Alibert-Bazin syndrome or granuloma fungoides, is the most common form of cutaneous T-cell lymphoma. Cutaneous lymphomas are an uncommon, heterogeneous group of non-Hodgkin lymphomas (NHLs) of T- and B-cell origin where the skin is the primary organ of involvement. This is a case of a 60-year-old Nigerian woman, who was diagnosed and managed as a case of chronic dermatitis but further investigations confirmed a diagnosis of MF; she was thereafter managed with topical glucocorticoids/chemotherapy and improved on these treatments. We make a plea for better awareness of the disease among physicians and pathologists in Africa.

An improved cockroach swarm optimization.

Hunger component is introduced to the existing cockroach swarm optimization (CSO) algorithm to improve its searching ability and population diversity. The original CSO was modelled with three components: chase-swarming, dispersion, and ruthless; additional hunger component which is modelled using partial differential equation (PDE) method is included in this paper. An improved cockroach swarm optimization (ICSO) is proposed in this paper. The performance of the proposed algorithm is tested on well known benchmarks and compared with the existing CSO, modified cockroach swarm optimization (MCSO), roach infestation optimization RIO, and hungry roach infestation optimization (HRIO). The comparison results show clearly that the proposed algorithm outperforms the existing algorithms.

Prevalence of HIV-related autoimmune haemolytic anaemia in Lagos, Nigeria.

BACKGROUND: Despite a high frequency of anaemia, a positive direct antiglobulin test (DAT) and bone marrow hyperplasia HIV-infected patients, lack of reticulocytosis may cause underdiagnosis autoimmune haemolytic anaemia (AIHA) in them. This study was carried out to determine the prevalence of autoimmune haemolytic anaemia in HIV-infected patients and to compare the haematological/immunological characteristics of subjects with anaemia and those without. MATERIALS AND METHODS: A total of 350 HIV-infected subjects attending the Lagos University Teaching Hospital who consented were recruited for the study. This included 250 subjects with anaemia (haemoglobin concentration <10 g/dl) as cases and 100 subjects without anaemia as controls. Five milliliters of venous blood drawn from each subject was used for the full blood count, reticulocyte count and DAT. RESULTS: Subjects with anaemia had lower mean CD4 cell count (284.3 cells/µl) and higher mean reticulocyte per cent (1.5%) than the non-anaemic subjects. The frequency of reticulocytosis was higher in female subjects than in males. Only 0.8% (2 of 250) of the study group screened positive to DAT, p = 0.0339. None of the subjects in control group screened positive to DAT. CONCLUSION: Autoimmune haemolytic anaemia is a rare complication of HIV infection in our geographical location.

Serum ferritin levels in adults with sickle cell disease in Lagos, Nigeria.

BACKGROUND: Serum ferritin is considered to be one of the most important tools in the measurement of iron balance in steady-state sickle cell disease. Increased gastrointestinal absorption of iron has been reported in sickle cell disease because of the associated chronic hemolysis, and it is also thought that repeated red cell transfusion consequent to chronic hemolysis and anemia causes excessive iron levels. The aim of this study was to determine overall and gender-specific mean ferritin levels in patients with steady-state sickle cell disease in order to establish the prevalence of iron deficiency and overload. METHODS: This was a cross-sectional study in homozygous patients with sickle cell disease attending the sickle cell clinic at Lagos State University Teaching Hospital, Ikeja. A 5 mL blood sample was collected in plain bottles from consenting participants during steady-state periods. The serum was separated and analyzed for ferritin by enzyme-linked immunosorbent assay. Another 5 mL sample was collected for a full blood count, done on the same day of collection, to determine red blood cell indices, ie, mean cell volume, mean cell hemoglobin concentration, and mean corpuscular hemoglobin concentration. The Pearson Chi-square test was used for statistical analysis. The differences were considered to be statistically significant when P was <0.05. RESULTS: In total, 103 patients were recruited for this study and comprised 58 women (56.40%) and 45 men (43.70%). The overall mean ferritin concentration was 93.72 ± 92.24 ng/mL. The mean ferritin concentration in the women was 92.00 ± 88.07 ng/mL and in men was 96.41 ± 99.80 ng/mL. Only eight (7.76%) of the 103 patients had a serum ferritin level < 15 ng/mL, while two subjects (1.94%) had a serum a ferritin level > 300 ng/mL. Ninety-three subjects (90.29%) had serum ferritin within the normal reference range of 15-300 ng/mL. CONCLUSION: In this study, 90% of subjects with sickle cell disease had normal iron stores; serum ferritin was higher in men than in women, and iron deficiency was more common than overload in the disease.

Oral arginine metabolism may decrease the risk for dental caries in children.

Arginine metabolism by oral bacteria via the arginine deiminase system (ADS) increases the local pH, which can neutralize the effects of acidification from sugar metabolism and reduce the cariogenicity of oral biofilms. To explore the relationship between oral arginine metabolism and dental caries experience in children, we measured ADS activity in oral samples from 100 children and correlated it with their caries status and type of dentition. Supragingival dental plaque was collected from tooth surfaces that were caries-lesion-free (PF) and from dentinal (PD) and enamel (PE) caries lesions. Regardless of children's caries status or type of dentition, PF (378.6) had significantly higher ADS activity compared with PD (208.4; p < .001) and PE (194.8; p = .005). There was no significant difference in the salivary arginolytic activity among children with different caries status. Mixed-model analysis showed that plaque caries status is significantly associated with ADS activity despite children's age, caries status, and dentition (p < .001), with healthy plaque predicting higher ADS activity compared with diseased plaque. Plaque arginine metabolism varies greatly among children and tooth sites, which may affect their susceptibility to caries.

Seroprevalence of Toxoplasma gondii IgG antibody in HIV-infected patients at the Lagos University Teaching Hospital.

BACKGROUND: Toxoplasmosis is caused by infection with a ubiquitous intracellular protozoan parasite, Toxoplasma gondii. With the advent of the HIV pandemic in Nigeria, toxoplasmic encephalitis has become one of the more frequent opportunistic infections and the most commonly implicated cause of focal brain lesions complicating the course of AIDS. OBJECTIVES: This study was conducted to compare the pattern of seroprevalence of T. gondii (Toxo-IgG) antibodies among HIV-infected persons presenting with neurological complications and those without. MATERIALS AND METHODS: Plasma specimens collected from 380 subjects were tested for Toxo- IgG antibodies by enzyme immunoassay technique and CD4 estimation by flow cytometry. Close-ended questionnaires were applied to all respondents to collect relevant data, with ethical approval from the hospital ethical committee. Plasma was obtained from two study groups comprising 300 HIV-positive respondents without neurological presentations, and 80 HIV-positive respondents with neurological complications. RESULTS: Seroprevalence of Toxo-IgG antibodies was 58% in the HIV-positive study group without neurological complications (of these, 79.2% were males and 38.5% were females) and 40% in the study group with neurological complications (46.2% of these were males and 28.6% were females). The overall seroprevalence of Toxo-IgG antibodies among the HIV-positive respondents (with and without neurological complications) was 54.2% (206 of 380). Seroprevalence of Toxo-IgG antibodies was lowest among the educated subjects (19% of the respondents with tertiary education) and among females in both study groups. A higher proportion of the subjects with neurological complications had CD4 cell count <100 cells/µL compared with respondents without neurological defects (39% vs 22.7%; P = 0.000), but the seroprevalence of Toxo-IgG antibodies was higher in subjects without neurological complications (45% vs 31.3%; P = 0.000). CONCLUSION: Toxoplasmosis, though an important opportunistic infection in our environment, may not account for the majority of neurological complications observed in patients with HIV infection in our center.

The incidence of adverse reactions following 4% septocaine (articaine) in children.

PURPOSE: The purpose of this study was to report the incidence of adverse events following the use of 4% Septocaine in children. METHODS: A prospective study was carried out on children attending university-based pediatric dental clinics for restorative core under local anesthesia. Data collection included patient demographics, medical history, amount and site of injection, and treatment complexity. Follow-up telephone interviews were conducted with the parents at 3, 5, 24, and 48 hours regarding prolonged paresthesia, soft tissue injury, and pain. RESULTS: Two hundred sixty-four 2 to 14 year-olds were recruited for the study. Complete interview information was obtained from 204 patients. Prolonged paresthesia at 3 hours postinjection was reported for 40% of the population and at 5 hours for 11%. Soft tissue injury occurred in 14% of the patients at 3 hours and was found to be highest among children younger than 7 years old. The lip was the most commonly affected site for accidental injury and it was not related to injection site. Twenty percent reported postprocedural pain at 3 and 5 hours post-treatment. CONCLUSIONS: Since prolonged numbness appears to be the most frequent adverse event and occurred primarily in children younger than 7 years old, parents need to be informed and reassured accordingly.

Stainless steel crown aspiration during sedation in pediatric dentistry.

Foreign body aspiration (FBA) causes death in more than 300 children every year in the United States. Morbidity and mortality are increased in children due to narrow airways and immature protective mechanisms. Factors to consider in pediatric dentistry are: (1) the patient's age and behavior; (2) presence and extent of disability; (3) local anesthesia; (4) body positioning; and (5) loose teeth. FBA requires prompt recognition and early treatment to minimize potentially serious and sometimes fatal consequences. The purpose of this case report was to describe the aspiration of a stainless steel crown in a 5-year-old boy during conscious sedation. It also discusses how a prompt and accurate diagnosis, early referral, and immediate treatment helped prevent serious complications.

Children and informed consent: a study of children's perceptions and involvement in consent to dental treatment.

AIM: The aim of the study was to find out to what extent children are involved in consenting to their dental care. METHODS: It was conducted using a structured interview with 60 8-13-year-old children. In the control group, verbal consent was given by the parent, whilst in the study group written consent was given by the parent and verbal assent by the patient. Interviews were conducted after dental treatment. RESULTS: The findings indicate that children in the study group felt they were more involved in deciding about their dental treatment compared with the control group. CONCLUSION: Children want to be more involved in consenting to their dental treatment.

An audit of X-ray investigations in patients attending a neuropsychiatric hospital.

Using a criterion audit which states that "X-ray Investigation should be requested in neuropsychiatric patients where indicated for concomitant physical problems, the case notes of all the new patients seen at the Neuropsychiatric Hospital, Aro, during the first six months of 1983 and who met this criterion were scrutinized for radiological investigations. 14.2% of the 336 patients who met this criterion had had X-ray investigation. Skull and chest X-rays were the most commonly requested. While routine X-ray requests were absolutely rare. Chest X-ray findings in particular necessitated referral to other specialists in 25% of the referred patients. The author postulated that a mandatory Chest X-ray would be invaluable in psychiatric patients.