Population dynamics of indoor sampled mosquitoes and their implication in disease transmission in Abeokuta, south-western Nigeria

Background & objectives: A longitudinal study was carried out to investigate the speciescomposition, seasonal abundance, parity and feeding preference of indoor sampled mosquitoes inAbeokuta, south-western Nigeria.Methods: The mosquitoes were sampled weekly from five stratified locations using Center forDisease Control (CDC) light-traps between August 2005 and July 2006. The mosquitoes wereexamined for abdominal condition and dissected for age composition. Microscopic and precipitintechniques were also employed for the determination of host blood source.Results: A total of 2969 mosquitoes which belong to 10 species of mosquitoes were collectedduring the study period. Mansonia africana (35.65%) constituted the most abundant species followedby Culex quinquefasciatus (32.23%) and Anopheles gambiae complex (13.52%). Other species indecreasing order of abundance were Coquilletidia maculipennis (8.2%), Aedes albopictus (5.9%),Ae. aegypti (1.93%), M. uniformis (1.81%), Cx. duttoni (0.25%), Cx. tigripes (0.25%) and An.funestus (0.25%). Seasonal abundance revealed a significant difference (p <0.05) in the populationof mosquito vectors collected during the wet season as compared to the dry season and theirabundance was positively correlated with rainfall. The results showed that the majority of thevector species collected were unfed and nulliparous. Moreover, the blood meal test was positive forhuman blood.Conclusion: The preponderance of mosquitoes observed in the study is of public health concernsince they serve as vectors of most tropical diseases including malari

An efficient framework to sustainable management of refuse collection and evacuation in a developing city

The study developed a framework for sustainable management of refuse collection and evacuation in Bauchi city through spatial modeling. Coordinates of dump sites and sample households from the study area were obtained by Global Positioning System (GPS) while road network was obtained by digitizing satellite image of the area and both were used in this research. Thus, digital map of dump sites, sampled households and roads about the area were produced. Using the “Network Analyst Tool (NAT)” of ArcGIS 10.2 functionalities for service areas, closest facilities and best routes, a model was then developed to encourage efficient and sustainable refuse collection and evacuation in the area. The model developed has 22 dump sites, 15 closest facilities and 3 trucks routes. The service areas around each dump site are in three buffer zones covering distances of 200m, 350m and 500m respectively while the longest and shortest distances of 1499.46m and 156m in the closest facilities for the households were confirmed. Also, three trucks with truck3 having the longest distance was discovered while truck1 has the least distance for refuse evacuation in the area. These were discovered based on service areas, closest facility and best routes and hence the model will improve the general situation of refuse disposal in the area. Moreover, it will specifically ensure efficiency and sustainability in the management of refuse collection and evacuation of the area. Therefore, spatial modeling through NAT looks more appropriate as panacea for inefficient and unsustainable management of refuse collection and evacuation of a developing Bauchi metropolis. Thus, the model is recommended to be used as an efficient framework for sustainable management of refuse collection and evacuation in similar developing cities.Keywords: Closest facilities, modeling, network analyst, route optimization, service area

Occurrence of malaria and utilization of antimalaria preventive measures amongst pregnant women attending Ajeromi- Ifelodun General Hospital, Lagos State, Nigeria

Malaria in Pregnancy poses a serious health problem both for the mother and her unborn baby and this can be prevented with the use of Intermittent Preventive Treatment with sulphadoxine pyrimethamine (IPTp-SP), Long Lasting Insecticidetreated Nets (LLIN) and other preventive measures. This cross-sectional survey was carried out among pregnant women attending Ajeromi Ifelodun General Hospital between August 2013 and February 2014. A total of 414 pregnant women (with mean age of 29±8.7) in their first (84), second (124) and third (206) trimesters were recruited for this study. Blood samples for making both thin and thick smears were collected and semi-structured questionnaires administered to the respondents. The questionnaire probed into their knowledge on cause of malaria, the preventive measures taken against mosquito bite, use of IPTp-SP, possession and use of LLIN. The overall prevalence of malaria due to Plasmodium falciparum is 24 (5.8%) out of which 13 were primigravid, 5 were secundi-gravid, and 6 were multigravida with no significant difference (P&gt;0.05) amongst them. Two hundred and eighty-six (69.1%) pregnant women had good knowledge of the cause of malaria. 164 (39.6%) of the sampled population had a tertiary education while 182 (44.0%) had secondary education, 124 (30.4%) were traders and 80(19.6%) were civil servants. Preventive measures claimed to be adopted by the respondents in avoiding mosquito bites include the use of LLIN (62.6%), insecticides sprays (36.2%), and locally adopted measures (1.5%). The number of respondents who had not availed themselves of IPTp-SP was significantly higher 258 (62.3%) compared to those who had (P&lt;0.05). It was observed that educational status had no significant effect on the knowledge of the cause of malaria in sample population (p&gt;0.05). The findings of this study reveal that there is a good knowledge on the cause of malaria among pregnant women but low use of IPTp-SP. In order to meet the new target of reaching an elimination stage set by the World Health Organization, factors responsible for the low use of these preventive measures should be investigated and quickly addressed so as to reduce both maternal and child morbidity/mortality resulting from malaria infection.Keywords: Malaria, Pregnant women, Prevention, Intermitent preventive treatment, Sulphadoxine-pyrimethamine, Longlasting Insecticide treated ne

Growth performance and nutrient utilization of post fingerlings Clarias gariepinus fed varied levels of biscuit waste

A feeding trial was conducted to determine the effect of biscuit waste meal on the growth performance and utilization of Clarias gariepinus juveniles. A total of 300 juveniles of average weight 8.85g were randomly divided into 5 Treatments, each with three replicates. Twenty juveniles were distributed into fifteen happas (0.7m3) and each happa was suspended to 3/4 of its volume using kuralon ropes carefully tied round the bamboo poles across the concrete tanks. Five diets containing 40% crude protein were formulated in which maize was replaced with biscuit waste meal at Treatment diet 1 (TD1) 0%, 25% (TD2), 50% (TD3), 75% (TD4), 100% (TD5) levels.The juveniles were fed at 3% body weight per day for 10 weeks. It was recorded at the end of the experiment that biscuit waste was most suitable as an energy supplement when incorporated at 25% replacement (TD2) with maize. TD1 had the highest weight gain followed by TD2, TD3, TD4 and TD5 respectively. There were no significant differences (P>0.05) in the growth response in TD1 (0%), T0D (25%) and TD3 (50%). It is therefore concluded that biscuit waste meal is a cheap source of non conventional energy source which can be used favorably to replace maize (25% inclusion level) as an energy source in the diets of Clarias gariepinus

Biomembrane Modelling in Planar Chromatographic Determination of Lipophilicity Using Olive and Castor Oils

BackgroundLipophilicity is a crucial physicochemical parameter that predicts in vivo pharmacokinetics and should be reliably estimated in early stage drug discovery to reduce incidence of attrition. Previous methodologies for its measurement often lead to technically incorrect decisions due to simplistic architecture and poor biomimetic attributes. Significantly, a certain seed oil, used for biomembrane modelling on planar chromatographic platform, was reported to be sufficiently biomimetic and fit for purpose.ObjectivesTo evaluate olive oil (OL) and olive-castor oil (OL-C) equi-mixture as lipids for biomembrane simulation on planar chromatographic platform.Material and MethodRetention behavior of nabumetone, a model compound was used to optimize these potential lipid membranes using a thin film engineered from 5% Liquid paraffin (LP) as benchmark, while halofantrine, nabumetone , α-naphthol and β-naphthol representing varying molecular polarities, were used for validation studies. The validation involved 2-way analysis of variance (ANOVA) associated with variability in Basic lipophilicity parameter (Rmw), and Specific hydrophobic surface area (SHSA) for the optimized surfaces, relative to LP and octadecylsilane (ODS) Further validation entailed correlation of the lipophilicity descriptor i.e. isocratic chromatographic hydrophobicity index (ICHI) on OL, OL-C, ODS and LP with experimental Log P(octanol/water).ResultsOptimized film thicknesses were produced by 5% OL and 1.25% OL-C (p &gt; 0.05). The 2-way ANOVA revealed great variability in performance characteristics of the surfaces (p &lt; 0.0001), and the new surfaces also gave poorer correlation with Log P values (R2= 0.502 and 0.449 respectively).ConclusionThe 1.25 % OL-C demonstrated a higher biomimetic attribute and warrants further validation studies to ascertain biorelevance, of lipophilicity measurement on this platform, in predicting oral drug absorption. Keywords: Lipophilicity, Reversed-phase Thin Layer Chromatography, Retention behaviour, Olive oil, Castor oi

Assessment of groundwater contamination around active dumpsite in Ibadan southwestern Nigeria using integrated electrical resistivity and hydrochemical methods

Investigation of groundwater contamination due to leachate migration in a solid waste disposal site was done using both geophysical and hydrochemical methods. The main goals were to delineate groundwater contamination due to leachate percolation and thus assessment of quality of groundwater from nearby hand-dug wells bordering the dumpsite for drinking purpose. A total of ten resistivity traverses were acquired within and outside the dumpsite using Wenner configuration with constant electrode separation ranging from 5 to 25 m. The 2D resistivity data were processed and inverted using RES2DINV and RES3DINV softwares, respectively. Geochemical assessment of groundwater samples were carried out according to APHA standards while hydrochemical facies of the sampled groundwater was evaluated using Piper Trilinear software. The inverse resistivity models of the subsurface from 2D and 3D imaging revealed low resistivity value less than 10 X m suspected to be leachate while 3D inverse sections allowed delineation of leachate, weathered layer, bedrock and seepage path from the dumpsite. The extent of migration was more pronounced in the southern part of the dumpsite, hence possible contamination of shallow groundwater system as dumpsite ages. The results of physico-chemical analyses showed the groundwater samples to be within the limits of WHO/NSDWQ for drinking purpose. However, higher values of concentrations of most analyzed parameters were noticed in well 1 due to its nearness to dumpsite and well 10 due to agricultural activities, respectively. Interpretation of Piper diagram showed CaHCO3 to be dominant facie in the area while alkaline earth metals (Ca2þ; Mg2þ) and weak acids (HCO3 -, CO3-) are dominant cations and anions during both climatic seasons. Groundwater in the study area is of hard, fresh and alkaline in natur

Evidence of Novel Susceptibility Variants for Prostate Cancer and a Multiancestry Polygenic Risk Score Associated with Aggressive Disease in Men of African Ancestry

Background: Genetic factors play an important role in prostate cancer (PCa) susceptibility. Objective: To discover common genetic variants contributing to the risk of PCa in men of African ancestry. Design, setting, and participants: We conducted a meta-analysis of ten genome-wide association studies consisting of 19 378 cases and 61 620 controls of African ancestry. Outcome measurements and statistical analysis: Common genotyped and imputed variants were tested for their association with PCa risk. Novel susceptibility loci were identified and incorporated into a multiancestry polygenic risk score (PRS). The PRS was evaluated for associations with PCa risk and disease aggressiveness. Results and limitations: Nine novel susceptibility loci for PCa were identified, of which seven were only found or substantially more common in men of African ancestry, including an African-specific stop-gain variant in the prostate-specific gene anoctamin 7 (ANO7). A multiancestry PRS of 278 risk variants conferred strong associations with PCa risk in African ancestry studies (odds ratios [ORs] &gt;3 and &gt;5 for men in the top PRS decile and percentile, respectively). More importantly, compared with men in the 40–60% PRS category, men in the top PRS decile had a significantly higher risk of aggressive PCa (OR = 1.23, 95% confidence interval = 1.10–1.38, p = 4.4 × 10–4). Conclusions: This study demonstrates the importance of large-scale genetic studies in men of African ancestry for a better understanding of PCa susceptibility in this high-risk population and suggests a potential clinical utility of PRS in differentiating between the risks of developing aggressive and nonaggressive disease in men of African ancestry. Patient summary: In this large genetic study in men of African ancestry, we discovered nine novel prostate cancer (PCa) risk variants. We also showed that a multiancestry polygenic risk score was effective in stratifying PCa risk, and was able to differentiate risk of aggressive and nonaggressive disease

Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic. Funding: Bill & Melinda Gates Foundation