Dataset Information

Diurnal and seasonal variations of the incoming solar radiation flux at a tropical station, Ile-Ife, Nigeria.

ABSTRACT: The diurnal and seasonal variations of the incoming solar radiation have been studied by analysing two years data measured between January, 2016 to December, 2017 at a Tropical station, Ile-Ife (7.53°N; 4.54°E), Nigeria. The maximum incoming solar radiation flux which occurs between 13:00 - 14:00 LT and varies in the course of the year from 639.5 ± 171.6 Wm^-2 (with large fluctuations) in the wet months (March - October) to 700.7 ± 105.2 Wm^-2 in the dry months (November - February). The large differences in the values, diurnal and seasonal variation of the measured incoming solar radiation between the dry and wet seasons are attributed to the attenuation of the flux by aerosol particles in the dry season and increased cloudiness and humidity in the wet season. The monthly maximum values of 760.3 Wm^-2 and 732.8 Wm^-2 indicated a double peak from March to May and October to November respectively while a minimum of about 492.7 Wm^-2 was recorded from July to August. Similarly, the daytime average had a double peak of 412.5 Wm^-2 and 361.3 Wm^-2 in March/April/May and October/November respectively, equally a minimum value of about 249.8 Wm^-2 was recorded in July/August. The maximum value of the air temperature (which occurs around 15:00 LT) was observed to lag behind the maximum value of the incoming solar radiation (which occurs around 13:00 LT) by 2 hours at the study site. The statistical analysis of the monthly daytime averages of the incoming solar radiation showed that the intensity of the flux received at Ile-Ife (a tropical location) is high (about 67% of the incoming solar radiation are between the interval 325 and 400 Wm^-2) throughout the year.

SUBMITTER: Soneye OO

PROVIDER: S-EPMC6525295 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Diurnal and seasonal variations of the incoming solar radiation flux at a tropical station, Ile-Ife, Nigeria.

Soneye Olanrewaju Olukemi OO Ayoola Muritala Ajayi MA Ajao Iyiola Adewale IA Jegede Oluwagbemiga Olawale OO

Heliyon 20190516 5

The diurnal and seasonal variations of the incoming solar radiation have been studied by analysing two years data measured between January, 2016 to December, 2017 at a Tropical station, Ile-Ife (7.53°N; 4.54°E), Nigeria. The maximum incoming solar radiation flux which occurs between 13:00 - 14:00 LT and varies in the course of the year from 639.5 ± 171.6 Wm<sup>-2</sup> (with large fluctuations) in the wet months (March - October) to 700.7 ± 105.2 Wm<sup>-2</sup> in the dry months (November - Fe ...[more]

PMID: 31193287

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Project description:BackgroundDiarrhoea is a leading cause of death among under-five children globally, with sub-Saharan Africa alone accounting for 1/3 episodes yearly. Viruses, bacteria and parasites may cause diarrhoea. Rotavirus is the most common viral aetiology of diarrhoea in children less than five years globally. In Nigeria, there is scarce data on the prevalence/importance, burden, clinical/risk factors and seasonality of rotavirus and bacteria and this study aims to determine the role of rotavirus and bacteria on diarrhoea cases in children less than five years in Ile-Ife, Nigeria.MethodsSocio-demographic data, environmental/risk factors and diarrhoiec stool samples were collected from children less than five years presenting with acute diarrhoea. Rotavirus was identified using ELISA. Bacteria pathogens were detected using cultural technique and typed using PCR. Diarrhoeagenic E. coli (DEC) isolates were subjected to antimicrobial susceptibility testing. Pathogen positive and negative samples were compared in terms of gender, age-group, seasonal distribution, and clinical/risk factors using chi-square with two-tailed significance. SPSS version 20.0.1 for Windows was used for statistical analysis.ResultsAt least one pathogen was detected from 63 (60.6%) children having gastroenteritis while 28 (44.4%) had multiple infections. Rotavirus was the most detected pathogen. Prevalence of rotavirus mono-infection was 22%, multiple infection with bacteria was 45%. Mono-infection prevalence of DEC, Shigella spp., and Salmonella spp. were 5.8% (6/104), 5.8% (6/104), and 2.9% (3/104) and co-infection with RVA were 23.1% (24/104), 21.2% (22/104) and 10.6% (11/104) respectively. All rotaviral infections were observed in the dry season. The pathotypes of DEC detected were STEC and EAEC. Parent earnings and mid-upper arm circumference measurement have statistical correlation with diarrhoea (p = 0.034; 0.035 respectively).ConclusionIn this study, rotavirus was more prevalent than bacteria and occurred only in the dry season. Among bacteria aetiologies, DEC was the most common detected. Differences in seasonal peaks of rotavirus and DEC could be employed in diarrhoea management in Nigeria and other tropical countries to ensure optimal limited resources usage in preventing diarrhoea transmission and reducing indiscriminate use of antibiotics.

Project description:Background:Furniture making industries are small scale businesses that commonly use organic solvents. There has been minimal focus on the health effects of this chemical hazard on the nervous system among furniture makers in Nigeria. Objectives:The present study aimed to assess the association between organic solvents exposure and neurobehavioral status of furniture makers, using electronic technicians as a comparison group. Methods:A comparative cross-sectional study design was employed. A sample size of 108 was calculated for each group. A semi-structured interviewer-administered questionnaire was used to obtain data on the socio-demographic variables and use of personal protective equipment (PPE). A proforma was developed to collect neurobehavioral assessment data. A checklist was used to assess the furniture makers' workshops. Air was sampled from all of the workshops in both the study and comparison groups to determine the concentration of total volatile organic compounds (TVOCs). Results:The use of PPE was poor in both the study and comparison groups, with no significant difference between them (34.4% and 37.7% respectively). Total volatile organic compound and formaldehyde (HCHO) concentrations were significantly higher at the furniture makers' workshops compared with electronic technicians (p<0.001) for both chemicals. The 8-hour time-weighted average of TVOC was also higher in the furniture makers' workshops (4.4±0.6 mg/m3) compared with the control group (0.3±0.3 mg/m3). The neurobehavioral symptoms score was significantly higher among the study group relative to the comparison group (p<0.001). There was a significant difference in the outcome of the auditory verbal learning test, total recall (p=0.005), and delayed recall (p=0.003). There was no significant association between solvent exposure index and findings from the simple reaction time test. Conclusions:Poor compliance with the use of PPE among furniture makers may increase their exposure to organic solvents. There were more neurobehavioral changes in the furniture makers with a higher exposure index. Measures are needed to educate artisans about workrelated chemical hazards and ensure compliance with basic occupational safety and hygiene standards. Participant Consent:Obtained. Ethics Approval:Ethics approval was obtained from the Health Research and Ethics Committee of the Institute of Public Health, Obafemi Awolowo University (IPH/OAU/12/1049). Competing Interests:The authors declare no competing financial interests.

Project description:BackgroundMaternal mortality ratio in Nigeria is one of the highest in the world. Near misses occur in larger numbers than maternal deaths hence they allow for a more comprehensive analysis of risk factors and determinants as well as outcomes of life-threatening complications in pregnancy. The study determined the incidence, characteristics, determinants and perinatal outcomes of near misses in a tertiary hospital in South-west Nigeria.MethodsA prospective case control study was conducted at the maternity units of the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife Nigeria between July 2006 and July 2007. Near miss cases were defined based on validated disease-specific criteria which included severe haemorrhage, hypertensive disorders in pregnancy, prolonged obstructed labour, infection and severe anemia. Four unmatched controls of pregnant women were selected for every near miss case. Three categories of risk factors (background, proximate, clinical) which derived from a conceptual framework were examined. The perinatal outcomes were also assessed. Bi-variate logistic regressions were used for multivariate analysis of determinants and perinatal outcomes of near miss.ResultsThe incidence of near miss was 12%. Severe haemorrhage (41.3%), hypertensive disorders in pregnancy (37.3%), prolonged obstructed labour (23%), septicaemia (18.6%) and severe anaemia (14.6%) were the direct causes of near miss. The significant risk factors with their odds ratio and 95% confidence intervals were: chronic hypertension [OR=6.85; 95% CI: (1.96 - 23.93)] having experienced a phase one delay [OR=2.07; 95% CI (1.03 - 4.17)], Emergency caesarian section [OR=3.72; 95% CI: (0.93 - 14.9)], assisted vaginal delivery [OR=2.55; 95% CI: (1.34 - 4.83)]. The protective factors included antenatal care attendance at tertiary facility [OR=0.19; 95% CI: (0.09 - 0.37)], knowledge of pregnancy complications [OR=0.47; 95% CI (0.24 - 0.94)]. Stillbirth [OR=5.4; 95% CI (2.17 - 13.4)] was the most significant adverse perinatal outcomes associated with near miss event.ConclusionsThe analysis of near misses has evolved as a useful tool in the investigation of maternal health especially in life-threatening situations. The significant risk factors identified in this study are amenable to appropriate public health and medical interventions. Adverse perinatal outcomes are clearly attributable to near miss events. Therefore the findings should contribute to Nigeria's effort to achieving MDG 4 and 5.

Project description:ObjectivesEliminating mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is central to WHO's target of reducing hepatitis B infection in children to <0.1% by 2030. While Nigeria accounts for 8.3% of the global burden, interventional studies on prevention of MTCT of HBV are hardly available. This study aimed to assess the impact of prevention of MTCT interventions on vertical transmission of HBV among pregnant women in Nigeria.DesignA prospective cohort study.SettingA University Teaching Hospitals Complex in Nigeria between 2015 and 2021.Participants10 866 pregnant women and their pre-existing children.InterventionsEligible pregnant women were screened for HBsAg using chromatographic immunoassay (Micropoint, USA). HbsAg-positive women had HBV serological assay done and their pre-existing children were screened. Women with HBV DNA ≥2 00 000 IU/mL and those positive for hepatitis B e-antigen (HBeAg) had 300 mg/day of Tenofovir Disoproxil Fumarate (TDF) in the third trimester. The newborns had hepatitis B vaccines and HB immunoglobulin (HBIG) administered, followed by testing for HBsAg at 9 months postnatally.Primary outcome measuresPrevalence of chronic hepatitis B infection in pregnancy, and the incidence of MTCT of HBV.ResultsOverall, 395 women had chronic HBV infection, giving a prevalence of 3.64%. Their mean age was 31.51±5.71 years, with a median parity of 1.2. Thirteen women (5.2%) were positive for HBeAg, seven (3.1%) of the 225 pre-existing hepatitis B-exposed children were HbsAg positive and 17 women had prenatal TDF. Overall, 376 women completed the study, with mean birth weight of 3.21±1.86 kg and perinatal mortality rate of 29.2/1000 births. Hepatitis Bvaccine-HBIG combination was administered to 260 newborns, while the others had hepatitis B vaccine alone. All the children tested negative to the HbsAg at 9 months.ConclusionEliminating MTCT of HBV infection through validated protocols in low and middle income countries with the highest burden of chronic HBV infections is feasible. National scale-up of such protocols is recommended.

Dataset Information

Diurnal and seasonal variations of the incoming solar radiation flux at a tropical station, Ile-Ife, Nigeria.

Publications

Diurnal and seasonal variations of the incoming solar radiation flux at a tropical station, Ile-Ife, Nigeria.

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