Mechanical and Chemical Properties of Reinforcement Bars Manufactured in Nigeria

Reinforcement bars, or REBAR for short, are mainly produced from metal scrap or iron ore, or a combination of both. Their manufacturing process has a significant effect on their properties, so also are the percentage concentration of various constituent elements and the cooling rate in the production process. This research work aims to study the physical and chemical properties of rebars manufactured in Nigeria vis-à-vis their suitability for construction purposes. The effect of chemical composition in rebar on steel stresses was studied. Rebar samples were collected at various points in Abuja and its environs and tested for their mechanical and chemical properties. The results show some tolerable and intolerable deviations from provisions of BS 4449 B500B 2005 indicating that some of the rebars are satisfactory for use in reinforced concrete works while others are not. Tests conducted on the rebars include Tensile Strength, Relative Rib Area, Percentage Elongation, Bend and Rebend, and Spectrometer tests, among other physical examinations. In some rebars, results showed moderate to vast deviation from minimum acceptable standard values as specified in BS 4449 B500B 2005 for yield stress, elongation, bar diameter, mass per kilogram, carbon equivalent, while there is satisfactoriness for other tested samples

Mechanical and Chemical Properties of Reinforcement Bars Manufactured in Nigeria

Reinforcement bars, or REBAR for short, are mainly produced from metal scrap or iron ore, or a combination of both. Their manufacturing process has a significant effect on their properties, so also are the percentage concentration of various constituent elements and the cooling rate in the production process. This research work aims to study the physical and chemical properties of rebars manufactured in Nigeria vis-à-vis their suitability for construction purposes. The effect of chemical composition in rebar on steel stresses was studied. Rebar samples were collected at various points in Abuja and its environs and tested for their mechanical and chemical properties. The results show some tolerable and intolerable deviations from provisions of BS 4449 B500B 2005 indicating that some of the rebars are satisfactory for use in reinforced concrete works while others are not. Tests conducted on the rebars include Tensile Strength, Relative Rib Area, Percentage Elongation, Bend and Rebend, and Spectrometer tests, among other physical examinations. In some rebars, results showed moderate to vast deviation from minimum acceptable standard values as specified in BS 4449 B500B 2005 for yield stress, elongation, bar diameter, mass per kilogram, carbon equivalent, while there is satisfactoriness for other tested samples

Factors associated with abnormal glomerular filtration rate among HIV-positive children at the University of Maiduguri Teaching Hospital, Maiduguri, Nigeria

Background: Renal disease is commonly encountered in patients with HIV infection. The estimated glomerular filtration rate (eGFR) provides a good assessment of the renal function and is widely used in screening populations that are at risk of renal dysfunction. We determined the prevalence of abnormal eGFR among HIV-positive children and factors associated with it.Methods: In a cross-sectional study, children aged 15 years and below were recruited through systematic random sampling from the Paediatrics Infectious Disease Clinic of the University of Maiduguri Teaching Hospital until the desired sample size of 250 was reached. Clinical and laboratory information was obtained from the patient records and used for clinical staging and immunological classification. Serum creatinine was measured using Jaffe’s reaction and eGFR calculated using the Schwartz formula. The data obtained were analysed using SPSS version 16.Results: A total of 157 (62.8%) children were on antiretroviral therapy (HAART) for periods ranging from 1 to 168 months (mean duration 66.1 ± 46.5 months). Ninety-three (37.2%) children had advanced disease representing WHO clinical stages 3 and 4, whereas 103 (41.2%) had advanced or severe immunosuppression. The mean eGFR of the study population was 102 ± 41 mL/min/1.73 m2. Fifty-two children (20.1%) had low eGFR (<2 SD below the mean eGFR for age and sex) and 6 (2.4%) had high eGFR (>2 SD above the mean eGFR for age and sex). A total of 23 (9.2%) children had moderate to severe renal impairment, defined as eGFR <60 mL/min/1.73 m2. Age, sex, socio-economic status, mode of transmission as well as history of HAART usage were not significantly associated with abnormal eGFR. However, relatively shorter duration of treatment with HAART, as well as advanced clinical or immunological stage were all significantly associated with abnormal eGFR.Conclusion: Renal dysfunction is common among children with HIV disease in Maiduguri with over a third of those affected having moderate to severe renal dysfunction. Abnormal renal function is more frequent among children with advanced clinical and immunological disease. We recommend the regular determination of eGFR and early initiation of HAART in all children with HIV disease

The Emergence of Anisotropic Superconductivity in the Nodal-line Semi-metal TlTaSe2

TlTaSe2 is a non-centrosymmetric quasi-2D crystal semi-metal hosting nodal-line topological features protected by mirror-reflection symmetry. Here, we investigated the superconducting properties of TlTaSe2 using the first-principles anisotropic Migdal-Eliashberg theory. The Fermi surface hosts well gapped multiband features contributed by the Ta 5d and Tl 6p orbitals. Moreso, anisotropic superconducting gaps were found to exist at 2.15 and 4.5 meV around the in-plane orbitals, coupling effectively with the in-plane phonons of the Ta and Tl atoms. Using the Allen-Dynes-modified McMillan formula, we found a superconducting transition temperature of 6.67 K, accompanied by a robust electron-phonon coupling constant {\lambda} of 0.970. This investigation provides valuable insights into the mechanisms underlying anisotropic superconductivity in TlTaSe2.Comment: 17 pages, 5 figure

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021:a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed.FundingBill &amp; Melinda Gates Foundation.<br/

Global, regional, and national burden of meningitis and its aetiologies, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background Although meningitis is largely preventable, it still causes hundreds of thousands of deaths globally each year. WHO set ambitious goals to reduce meningitis cases by 2030, and assessing trends in the global meningitis burden can help track progress and identify gaps in achieving these goals. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we aimed to assess incident cases and deaths due to acute infectious meningitis by aetiology and age from 1990 to 2019, for 204 countries and territories. Methods We modelled meningitis mortality using vital registration, verbal autopsy, sample-based vital registration, and mortality surveillance data. Meningitis morbidity was modelled with a Bayesian compartmental model, using data from the published literature identified by a systematic review, as well as surveillance data, inpatient hospital admissions, health insurance claims, and cause-specific meningitis mortality estimates. For aetiology estimation, data from multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature studies were analysed by use of a network analysis model to estimate the proportion of meningitis deaths and cases attributable to the following aetiologies: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococcus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Staphylococcus aureus, viruses, and a residual other pathogen category. Findings In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000–277 000) and 2·51 million (2·11–2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400–145 000) and 1·28 million incident cases (0·947–1·71) in 2019. Age-standardised mortality rates decreased from 7·5 (6·6–8·4) per 100 000 population in 1990 to 3·3 (2·8–3·9) per 100 000 population in 2019. The highest proportion of total all-age meningitis deaths in 2019 was attributable to S pneumoniae (18·1% [17·1–19·2]), followed by N meningitidis (13·6% [12·7–14·4]) and K pneumoniae (12·2% [10·2–14·3]). Between 1990 and 2019, H influenzae showed the largest reduction in the number of deaths among children younger than 5 years (76·5% [69·5–81·8]), followed by N meningitidis (72·3% [64·4–78·5]) and viruses (58·2% [47·1–67·3]). Interpretation Substantial progress has been made in reducing meningitis mortality over the past three decades. However, more meningitis-related deaths might be prevented by quickly scaling up immunisation and expanding access to health services. Further reduction in the global meningitis burden should be possible through low-cost multivalent vaccines, increased access to accurate and rapid diagnostic assays, enhanced surveillance, and early treatment.publishedVersio

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Application of likelihood ratio and posterior probability density in sex estimation from level two fingerprint features among Hausa ethnic group

Abstract Background In forensic sciences, the nature and variability of configurations of epidermal ridge minutiae has practically been explored in the evaluation and comparison of fingerprints, including partial fingerprints. The objectives of the present study were to determine the potential of fingerprint minutiae (level two features) in estimation of sex using likelihood ratio and posterior probability density among Hausa population. Secondly, to determine which of the minutiae have more of the estimation power compared to others. Methods A total of 420 thumbprints from 210 participants were analyzed. The minutiae density was determined within a circle whose diameter cuts 18 ridges and passing through the nucleus of the fingerprints. Posterior probability density and likelihood ratio were used to estimate the sex. Results The results showed that the median of minutiae count in males tends to be significantly higher in right ridge ending and ridge enclosure. Similarly, in the left thumb, the significantly higher minutiae count in males was observed in the ridge ending and ridge dot. In all the minutiae types, higher minutiae density favors males compared to the females. Likewise, in all the minutiae density, except for right ridge convergent and bifurcation and ridge ending, absence of any of the minutiae in the thumb favored female participants. Conclusion Increase in minutiae density was likely to infer males more than females. Ridge ending minutiae was observed to have higher discriminating power shown by higher likelihood ratio for sex inference among Hausa population

YETİŞKİN WISTAR SIÇANLARINDA SEREBRAL KAN DAMARLARININ HİSTOMİMARİSİ ÜZERİNDEKİ DİKLORVOS ETKİSİ

Cerebral blood vessels are vital in supplying brain in both human and animals. Any anomaly by rupture or interruption of blood flow may lead to fatal consequences. Dichlorvos is a volatile organophosphate that forms the active ingredient of locally formulated insecticide and pesticide known as Otapiapia or Madararpiapia. It is an anti-acetylcholinestrase that binds irreversibly to acetylcholinesterase and leads to its inhibition. The study aims to determine the effects of dichlorvos on the histology of the cerebral vessels in adult wistar rats. Twenty five apparently healthy adult wistar rats were randomly selected and divided into five groups. The first two groups were used as control while the last three groups were exposed to graded doses of dichlorvos in ethanol solution and experimented for twenty eight days. Twenty four hours after the last exposure the animals were sacrificed and the brain tissues were collected for routine histological technique. The relative brain weights of all the animals were determined and one – way ANOVA was conducted to compare the mean of the control with the treated groups. There was no statistically significant difference [F = 0.88, p = 0.49] in the mean brain weights of the controls and the treated groups. The H&E stain of the treated groups showed variable degrees of perivascular oedema, pyknosis and apoptosis. Prolong use of dichlorvos could cause cerebral vascular changes in the histoarchitecture such as perivascular oedema and apoptosis, may not affect the brain weigh

Gender preference between traditional and PowerPoint methods of teaching gross anatomy

Introduction: Teaching and learning process is increasingly metamorphosing from the traditional chalk and talk to the modern dynamism in the information and communication technology. Medical education is no exception to this dynamism more especially in the teaching of gross anatomy, which serves as one of the bases of understanding the human structure. Objective: This study was conducted to determine the gender preference of preclinical medical students on the use of traditional (chalk and talk) and PowerPoint presentation in the teaching of gross anatomy. Subjects and Methods: This was cross-sectional and prospective study, which was conducted among preclinical medical students in the University of Maiduguri, Nigeria. Using simple random techniques, a questionnaire was circulated among 280 medical students, where 247 students filled the questionnaire appropriately. The data obtained was analyzed using SPSS version 20 (IBM Corporation, Armonk, NY, USA) to find the method preferred by the students among other things. Results: Majority of the preclinical medical students in the University of Maiduguri preferred PowerPoint method in the teaching of gross anatomy over the conventional methods. The Cronbach alpha value of 0.76 was obtained which is an acceptable level of internal consistency. A statistically significant association was found between gender and preferred method of lecture delivery on the clarity of lecture content where females prefer the conventional method of lecture delivery whereas males prefer the PowerPoint method, On the reproducibility of text and diagram, females prefer PowerPoint method of teaching gross anatomy while males prefer the conventional method of teaching gross anatomy. Conclusion: There are gender preferences with regard to clarity of lecture contents and reproducibility of text and diagram. It was also revealed from this study that majority of the preclinical medical students in the University of Maiduguri prefer PowerPoint presentation over the traditional chalk and talk method in most of the questions ask