Open Access

Background and methods: Idiopathic autism, suspected to be caused by exposure of genetically susceptible individuals to unknown environmental triggers, has increased dramatically in the past 25 years. The objectives of our study were to determine, using a linear regression model, whether the county prevalence of autism in the Pacific Northwest of the United States was associated with the source of drinking water for that county and whether this relationship was dependent on the level of environmental pollutants and meteorological factors in the county. Results: We found the previously reported relationship between precipitation and autism in a county was dependent on the amount of drinking water derived from surface sources in the county. We also found a positive association between the EPA’s risk of neurological disease and autism, but this relationship was only present in warm areas. Conclusions: Our study provides evidence for the hypothesis that environmental factors are associated with autism and that meteorological factors play a role in this relationship

Optimization of Absorber Layer and Operating Temperature of Copper Indium Gallium Selenide Solar Cells Using Different Metal Contacts

Device simulation was employed to investigate the effect of metal back contact electrodes on the performance of n-type CdS/p-CIGS thin film solar cells using varying thicknesses of absorber layer at operating temperature of 300K. The effect of working temperatures was also studied from 300K to 400K in steps of 10K. The simulations were carried out using standard solar cell capacitance simulator (SCAPS) 3.3.03 version software. The results showed better efficiencies at the optimized thickness of 3µm for all the back contact electrodes under study. The maximum efficiencies of 17.5 %, 15.5 %, 11.5 %, 3.5 % and 3 % were estimated for CIGS thin film solar cell at 300 K for platinum, gold, cobalt, silver and copper back contact electrodes respectively. The efficiency decreases as the operating temperatures increases from 300 K to 400 K. It is recommended that the optimized thickness of 3 µm is appropriate as absorber layer for efficient and cost effective CIGS thin film solar cells for economic reasons

Compliance to Annual Ivermectin Treatment in Abia State, South Eastern Nigeria

A study with the objective of determining the rate of individual compliance to annual ivermectin treatment was conducted in Abia State, south eastern Nigeria between January and November, 2011. The study captured the Local Government Areas in  Abia State that were assessed by Rapid  Epidemiological Mapping for Onchocerciasis (REMO) as being hyper-endemic for onchocerciasis and which have been receiving ivermectin for over 14 years. A study questionnaire was designed to investigate the rate of compliance and this was distributed to 558 individuals. The result showed that out of 558 individuals, 309 (55.4%) had taken the drug before while 249 (44.6%) claimed they have not been treated before. Despite the treatment over time, only 70 (22.7%) of those treated before were high compliers (that is, those who had been treated eight times and above). The overall percentage of high compliers in the sampled communities was only 12.6%. Reasons for low compliance include “lack of information on the arrival of drug” (27.8%), “no reason for refusal” (22.2%),” absent, away from village” (20.0%) and “no distribution” (19.7%). In testing the reasons for low compliance, the Chi-square analytical technique on the data revealed that the reasons given by the respondents for low compliance were not significant (?2cal = 1.797 < ?2tab = 16.9190), and therefore do not affect general compliance. Key words: Compliance, Annual ivermectin treatment, Onchocerciasi

A Study of the Effect of Electrode Gap on the Production of Hydrogen from Aluminium/Copper Fuel Cell

In this work, we investigated the effects of electrode gap spacing on the amount of hydrogen produced in Aluminium/Copper Fuel Cell and its efficiency. Aluminium/Copper materials were used as the electrodes because of their high performance in the electrolyser systems while Potassium Hydroxide (KOH) was used as electrolyte. 10% concentration of potassium hydroxide was used throughout the experiment. The electrode spacing of 5mm and 10mm were used. It was observed from the graph that 5mm electrode spacing produced maximum efficiency of 29.7% and 10mm electrode spacing produced 17.7% efficiency. This implied that hydrogen production was highly dependent on electrode gap distance. The smaller the gap between the pair of electrodes, the more hydrogen was produced and the more efficient is the system

A NEURAL NETWORK SYSTEM FOR DETERMINING THE OPTIMAL PROFITABILITY OF SMOKED FISH BUSINESS IN NIGERIA

Small scale smoked fish business is a lucrative business venture in Nigeria as market fish sellers especially women living inriverside areas of the country earn a living from this business. However, these fish sellers they may not know thecombination of smoked fish type that will yield optimum profit. In this research, a neural network model was designed forachieving this purpose and was used to predict the profitability of smoked fish business based on the analysis from thesample survey of smoked fish sellers/retailers in selected markets in Ota, in Ogun State, Nigeria, and its environs, . Thisprediction results could help government and small scale smoked fish retailers to fashion out best practices to help achievemaximum profitability in the smoked business.Keywords: Neural Network, Profitability, Smoked Fish Business, Voice Communication, Ogun State, Nigeri

Neuropharmacological evaluation of Annona senegalensis leaves

The neuropharmacological activities of methanol leaf extract (ME) of Annona senegalensis Pers (Annonaceae) and its bioactive fractions (MF and F7) were studied in rodents using pentylenetetrazol (PTZ)-induced seizures, pentobarbitone-induced sleep, apomorphine-induced stereotypy, open field, elevated plus maze (EPM) and rotarod performance tests. The extract and fractions inhibited PTZ-induced seizures, prolonged pentobarbitone-induced sleep, reduced stereotypic behaviour induced by apomorphine, decreased the frequency of line crossing and centre square entries and increased rearing in the air in the open field. The frequency of grooming and rearing against the wall were decreased, whereas the duration of grooming increased. Also, the extract and fractions increased the duration of stay in the open arm when compared to the closed arm of the EPM, and reduced the average time spent on the rotarod. Acute toxicity test showed an oral LD50 of ME greater than 5 g/kg in mice. Phytochemical analysis showed that ME tested positive for carbohydrates, reducing sugar, resins, saponins,  tannins, steroids, terpenoids, alkaloids, flavonoids and glycosides; MF tested positive for saponins, steroids, terpenoids, alkaloids, carbohydrates, reducing sugar, flavonoids and glycosides; while F7 tested positive for flavonoids. These findings suggest that leaves of A. senegalensis possess anticonvulsant, central depressant and anxiolytic-like properties attributable to flavonoids.Keywords: Annona senegalensis, anticonvulsant, anxiolytic, sedative, stereotypy

Radiation Shielding Properties of Synthetic Ca-Al2O3 Polymer Based Composites

Ionizing radiation exposure from medical diagnostic equipment, industries, nuclear research facilities, and nuclear weapon development has led to health impacts such as cancer and acute radiation syndrome, necessitating the use of proper radiation shielding. The optical and radiation shielding capabilities of Ca-Al2O3 polymer-based composites were explored in this article. The composites were made by combining synthesized Aluminum oxide (Al2O3) with calcium (Ca) formed from Periwinkle shells, Snail shells, and Seashells and calcining them at 1000 oC for 13 hours. The synthesized Ca-Al2O3 powders were dispersed into polymeric materials in a ratio of 1:1 using an effective melt-mixing process, then cast in a 10 cm by 10 cm square Mold with a thickness of 10 mm and allowed to set overnight at ambient temperature. The composite samples obtained were transferred to the Nigerian Nuclear Regulatory Agency (NNRA) in Ibadan for radiographic examinations and analyses. X-ray transmission through the manufactured composites samples was investigated using a well-collimated point source. The produced x-rays' initial intensity (Io) was determined. With the sample in front of the detector, the transmitted x-ray beam (I) was measured. The measurements were repeated three times for each composite sample, and the average value was calculated. Using relevant and referenced equations, the linear attenuation coefficient, half-value layer, relaxation length, and absorbance for each sample were calculated. The radiation shielding composites' x-ray photon absorptions were determined using transmission data by Beer's Lambert law. The XRF results revealed that the calcined samples were mostly calcium with only a few traces of other elements, with percentage calcium quantities of approximately 32, 37, and 34 for snail shells, seashells, and periwinkle shells, respectively, and the XRD result confirmed the Al2O3 polymorphs at approximately 32o and 57 o and the Aluminum phase at 46 o. For the three radiation shielding composites under investigation, the x-ray photon transmittance is quite low at 40 keV to 60 keV and comparatively high at 100 keV to 200 keV. From 100 keV to 200 keV, the transmittance of periwinkle shells and snail shell calcium sources polymer-based composites was similar, and their differences became significant at lower energies. For Ca-Al2O3 polymer-based composites with calcium contents sourced from seashells, periwinkle shells, and snail shells, the maximum linear attenuation coefficients were 1.0 cm-1, 0.79 cm-1, and 0.65 cm-1, respectively. At 60 keV and below, the radiation shielding composites have the highest attenuation coefficient. The half-value layer (HVL) of all the samples under investigation reduced abruptly at 40 and 60 keV and grew linearly as the energy increased from 100 to 200 keV. The relaxation length is comparatively low at 40 and 60 keV compared to other x-ray sources utilized at higher energies. Each radiation shielding composite's properties are determined by the amount of calcium present in the samples. Over a certain photon energy range (40 keV–200 keV), the Ca-Al2O3 polymer-based composites with calcium contents sourced from seashells were found to have higher x-ray attenuating characteristics than other composites. The attenuating capacity of all the composites under this study can be enhanced by increasing the radiation shielding composite thickness.     &nbsp

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700