Objective To assess perception and level of proper utilization of emergency contraception （EC） among female undergraduates. Methods Cross-sectional questionnaire study was performed on 383 female undergraduates in N...Objective To assess perception and level of proper utilization of emergency contraception （EC） among female undergraduates. Methods Cross-sectional questionnaire study was performed on 383 female undergraduates in Nigeria in June 2006. Data analysis was with Z-square test and logistic regressions （P 〈O. 05）. Results One hundred and five （48.2%） had been sexually exposed. Only 32 （30.5%） used regular contraception. Seventy-three （24.3%）female undergraduates were aware of EC. Only 29 （7.6%） had used EC before. Most would not use emergency contraceptive drugs in future due to lack of awareness （64.8%）, and fear for future fertility and of drugs being injurious to health. Use of EC was associated with awareness of correct interval for use （OR=9.1; 95%CI： 2.1-39.9）. Conclusion There is poor knowledge about EC and poor use, while significant need remains. Most knowledge was acquired from peers and inaccurate. Peer educators are important and professionals＇ knowledge needs improvement.展开更多
Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not consid...Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not considered biodegradable or compostable can take several hundred years to degrade.Each year in the United States,only 9%of overall plastic waste is recycled while 79%is accumulated in landfills or the natural environment.Recycling of plastic mulch is especially constrained due to the contamination that results from their use in farming.Currently,recovered mulches are reported to have 30%–80%surface contamination,primarily from soil and plant debris.Plastic mulch waste is concentrated in areas where they are used and can provide logistical opportunities to the plastic recycling industries.Plastic recycling includes mechanical,advanced(chemical and thermal),and biological methods,that may all be used for polyethylene(PE).Most plastic is recycled using the mechanical method,while advanced and biological methods are promising but face significant financial and technical challenges.For all recycling methods,strategies are needed for managing surface contamination to realize the recycling potential of plastic mulch.展开更多
Open burning of municipal solid waste(MSW)is a common practice in Nigeria.Emission of compounds of polycyclic aromatic hydrocarbon(PAHs)in ambient air and ash residues from burning of these wastes pose a great danger ...Open burning of municipal solid waste(MSW)is a common practice in Nigeria.Emission of compounds of polycyclic aromatic hydrocarbon(PAHs)in ambient air and ash residues from burning of these wastes pose a great danger to the environment.This study investigated the contribution of open burning of MSW to the levels of PAHs in ambient air and ash residues from the burning site.Ash samples were obtained from six sampling locations at a MSW burning site.Polyurethane foam passive samplers were used in collecting ambient air samples.Quantification of PAHs was carried out using GC-MS operated in selected ion monitoring mode.The trend of ambient concentration of PAHs was;ΣPAHs AS-A(4.023)>AS-B(3.798)>AS-D(3.468)>AS-C(3.288),while average concentration of PAHs in the ash was 6.12 mg/kg.Concentrations of PAHs in ash samples ranged from 5.69-6.34 mg/kg.Principal component analysis(PCA)showed that most of the PAHs in the ambient were from MSW combustion.The results obtained suggest that concerted effort of the government and the relevant stakeholders is required to safeguard the environment and humans from PAH pollution from open burning of MSW.展开更多
Background: COVID-19 is a disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Epidemiological data indicated that bacterial complications in COVID-19 would decrease clearance rate of the in...Background: COVID-19 is a disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Epidemiological data indicated that bacterial complications in COVID-19 would decrease clearance rate of the infecting agent and increase mortality rate. Macrolides such as Azithromycin are usually administered to COVID-19 patients as palliative treatments. Currently, a considerable number of bacterial strains have developed resistance to various antibiotics, especially macrolides. Resistance is reported to be due to possession of mefA, ermB, and mphA genes by Gram positive and Gram negative bacteria. Therefore, this study determined antibiotic resistance patterns and identify mefA, ermB and mphA macrolide-resistant genes in bacterial pathogens isolated from COVID-19 cases in Ibadan, Nigeria. Methods: 400 Nasopharyngeal samples were collected from symptomatic cases before antibiotic medication;structured questionnaires were administered to collect socio-demographic data of participants. Samples were cultured on Blood, Chocolate, MacConkey and Mannitol salt agar at 37°C for 48 hrs. Bacterial identification was performed using VITEK 2.0 ID cards and API 20E for Gram positive and negative bacteria respectively. Antibiotic Susceptibility Testing was performed using Kirby Bauer disc diffusion methods and VITEK 2.0 AST card kits. DNA of multidrug resistant bacterial isolates was extracted;resistant genes were determined using a polymerase chain reaction with specific primers. Amplified genes were detected using agarose gel electrophoresis. Results: 240 (60%) had bacterial growth and 97 (22.2%) yielded no growth. From the 240 bacterial isolates, 38 (15.83%) were multi-drug resistant including resistance to macrolides (Azithromycin) 20 (52.63%) of which were positive for either mefA or ermB, and none (0.0%) possess mphA gene;14 (36.8%) isolates had mefA gene, 10 (26.3%) isolates carried ermB gene. Conclusion: Multi-drug bacterial resistance including macrolides and quinolones was detected. Only mefA and ermB genes w展开更多
This study deals with the physico-chemical, mineralogical and geotechnical characterization of alluvial clays from Batchenga in Cameroon with a view to their use as building materials for housing. The alluvial clay (A...This study deals with the physico-chemical, mineralogical and geotechnical characterization of alluvial clays from Batchenga in Cameroon with a view to their use as building materials for housing. The alluvial clay (Arg.All) was collected in the locality of Batchenga at the village Natchigal (4˚20'40''N and 11˚37'40''E at 378 m altitude) and was fired between 900˚C and 1100˚C. Characterization was performed by XRD, XRF, DTA/DTG, and firing tests. XRD, XRF, DTA/DTG infrared analysis methods were performed on these clays. The linear shrinkage, mechanical strengths, water absorption, porosity and density were measured on the fired products. The results obtained show that the major oxides are for the Arg.Lat SiO<sub>2</sub> (72.13%), Al<sub>2</sub>O<sub>3 </sub>(14.1%), Fe<sub>2</sub>O<sub>3</sub> (4.45%) and for the Arg.All: SiO<sub>2</sub> (48.91%), Al<sub>2</sub>O<sub>3</sub> (23.79%), Fe<sub>2</sub>O<sub>3</sub> (9.54%). The fired products based on alluvial clay, present the flexural strength of 4.45 MPa at 900˚C and 6.80 MPa at 1100˚C. As for those based on lateritic clay, the flexural strength is 0.53 and 0.76 MPa respectively at 900 and 1100˚C. The porosity is 33.69% at 900˚C and 22.93% at 1100˚C for the alluvial clay and 39.55% at 900˚C and 36.01% for the lateritic clay at 1100˚C. Water absorption is 18% to 11.16% for alluvial clay and 22.43% to 21.16% for lateritic clay at 900˚C and 1100˚C respectively. These results suggest that alluvial clay and its firing products have better physico-chemical, geotechnical and mechanical characteristics regardless of the firing temperature of the manufactured products. The addition of degreaser is recommended to improve the mechanical performance of lateritic clay.展开更多
The musculo-skeletal system is commonly affected in sickle cell disease, manifesting itself as bone infarction, femoral head osteonecrosis, osteomyelitis, myonecrosis, myofibrosis and fascitis. Myositis and fasciitis ...The musculo-skeletal system is commonly affected in sickle cell disease, manifesting itself as bone infarction, femoral head osteonecrosis, osteomyelitis, myonecrosis, myofibrosis and fascitis. Myositis and fasciitis are observed during a vaso-occlusive crisis in 4% of patients. Pain and swelling of bilateral proximal groups of muscles of upper and lower limbs are common presenting complaints due to prolonged sickling crises [1]. We report a case of 30-year old known HbSS patient with bilateral knee stiffness of two months duration, with associated swelling and warmth of both thighs. No preceding history of trauma. He was said to suffer at least two sickling crises in a month with the last one occurring one week prior to presentation. X-ray of the thigh showed no calcification in muscle groups. He was commenced on flexion-extension exercises.展开更多
Emulsions are difficult to transport in the oil and gas industry due to its water content and high viscosity property, thus a need arises to break these emulsions down into lighter emulsions that would make it a lot m...Emulsions are difficult to transport in the oil and gas industry due to its water content and high viscosity property, thus a need arises to break these emulsions down into lighter emulsions that would make it a lot more suitable for transportation. In this research, biodiesel was synthesized and used to break down relatively viscous emulsion samples into lighter emulsion samples. An apparatus was designed with the aim of determining the flowrate of four different samples in different proportions and compositions: 80% oil and 20% water (sample A), 90% sample A + 10% of biodiesel by volume (sample B), 75% of sample A + 25% of biodiesel by volume (sample C), 60% of sample A + 40% biodiesel by volume (sample D). The results showed that it was possible to significantly increase the flow of emulsions by injecting biodiesel, which was acted as a surfactant, resulting in the lowering of the surface tension of the emulsion sample. The relevance of this research work is validated as it proffers a solution to the transportation of heavy oil and emulsions from all over the world possessing the non-Newtonian flow behavior, which results in serious problems related to its transportation.展开更多
BACKGROUND Unexplained infertility(UI)is usually used for any heterosexual couple who failed to have a successful clinical pregnancy without identifying clear causes after they undergo all standard fertility tests.Evi...BACKGROUND Unexplained infertility(UI)is usually used for any heterosexual couple who failed to have a successful clinical pregnancy without identifying clear causes after they undergo all standard fertility tests.Evidence shows that leptin is one of the most accurate biomarkers for UI.Nevertheless,conflicting results regarding leptin levels in women with UI have been reported.AIM To find the serum leptin levels in women with UI.METHODS All studies written in English and conducted before April 30,2021 from PubMed/MEDLINE,Embase,Cochrane Central Register of Controlled Trials,ClinicalTrials.gov,Google Scholar,OpenGrey,OATD,and the infertility conference abstract were included.Studies were found eligible if they provided the mean and standard deviation of leptin for the case group and control group.The quality assessment of individual studies was evaluated using the Joanna Briggs Institute Quality Assessment Tool.Data synthesis and statistical analysis were done using STATA software version 16.RESULTS A total of 378 studies were reviewed,and just six studies that fulfilled the eligibility criteria were included in this meta-analysis.The pooled result showed that leptin levels were significantly higher in women with UI compared to fertile women,with a standardized mean difference of 0.97(95%confidence interval:-0.49-2.43).However,heterogeneity across studies was highly significant(P<0.00001;I2=98.8%).CONCLUSION The results of this study suggest that leptin levels are elevated in women with UI compared with fertile women;hence,leptin could be a potential biomarker for UI in women,and it may be useful for identifying women with a high risk of infertility.展开更多
The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review...The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review presents the various dynamics of oil spill, conventional clean-up technologies and silica aerogel synthesis techniques. It also highlights some investigations of oil spill sorption using aerogels. The future prospect of rice husk as a cheaper source silica aerogel is also considered.展开更多
The effect of crude oil pollution on heavy metal content in the soil, microbial population, and growth performance of maize and cowpea was investigated. The heavy metals determined were lead, cadmium, iron, nickel, zi...The effect of crude oil pollution on heavy metal content in the soil, microbial population, and growth performance of maize and cowpea was investigated. The heavy metals determined were lead, cadmium, iron, nickel, zinc and copper. Microbial population and growth performance of maize and cowpea in both polluted and unpolluted soils samples were evaluated. Results showed that higher concentration of heavy metals was observed in all crops planted in polluted soil, polluted site vegetation and soils. The total heterotrophic bacteria was 89% lower in the polluted soil than in the unpolluted soil while fungi was 78% lower in the polluted soil when compared to the unpolluted soil. However, hydrocarbon utilizing bacteria and fungi was 22% and 24% higher in the polluted soil than in the unpolluted soil respectively. Maize and Cowpea performed poorly in polluted soil when compared with unpolluted soil as evidenced in the growth parameters measured for both crops.展开更多
The petroleum paleo-productivity and generative potential of the Nkporo and Awgu shales in the Lower Benue Trough (LBT) were studied. Major oxides were determined using Spectro Ciros Inductively-coupled plasma optical...The petroleum paleo-productivity and generative potential of the Nkporo and Awgu shales in the Lower Benue Trough (LBT) were studied. Major oxides were determined using Spectro Ciros Inductively-coupled plasma optical emission spectrometer (ICP-OES) while trace and rare earth elements were determined using an ELAN 9000 Inductively-coupled plasma mass spectrometer (ICP-MS). The shales have Co/Ni ratios greater than 0.1 suggesting oil source rocks with more marine source input due to brief marine incursion in the transition zone after deposition. The very low Ni values and moderate V values, and a lack of correlation between the TOC and sulphur content, suggests that the organic matter is of terrestrial Type Ⅲ;and the very low paleo-productivity (Ba/Al and P/Ti ratios) suggests that the organic matter is of terrestrial origin. The low V/Ni values of the Nkporo and Awgu shales (Av. ≈ 4) and the high metal concentrations indicate a matured status. From the K/Rb ratios of the Nkporo (191–259) and Awgu shales (198–261), it can be deduced that the organic matter within the shales experienced a considerable loss of K and the shales are mature to generate gaseous hydrocarbons.展开更多
BACKGROUND Female infertility with unknown causes(unexplained)remains one of the mysteries in the reproductive health field,where the diagnostic evidence is still weak and the proposed treatments still work with unkno...BACKGROUND Female infertility with unknown causes(unexplained)remains one of the mysteries in the reproductive health field,where the diagnostic evidence is still weak and the proposed treatments still work with unknown methods.However,several studies have proposed some possible causes and risk factors for unexplained female infertility.AIM To characterize and identify factors associated with unexplained infertility in Sudanese women.METHODS A matched(age and body mass index)case-control study was conducted from March 2021 to February 2022.The study samples were 210 women with unexplained infertility(UI)and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum,Sudan.The risk factors of unexplained infertility were identified using a structured,pretested questionnaire containing information on socio-demographic variables,anthropometrics,clinical diagnosis of infertility,behavioral factors,physical activity assessment,diversity,and consumption of different food groups by the study participants.RESULTS The results showed a higher proportion of women diagnosed with UI were residents of rural areas than controls(21.4%vs 11.1%,P<0.05),and previous miscarriages and/or abortions were more common in fertile women compared with infertile women(13.16%vs 5.71%,P<0.05).Additionally,infertile women had a significantly(P<0.05)higher proportion of family history of infertility(explained and unexplained)compared with controls.Finally,after controlling for the effects of potentially confounding variables using multivariable logistic regression analysis,only marital status,family history of infertility,use of modern contraceptives,smoking,caffeine consumption,physical activity level,meals consumed,other vitamin-A-rich fruits and vegetables,and other vegetables were found to be significant(P<0.05)factors associated with unexplained infertility among Sudanese women.CONCLUSION Married women with a family history of infertility who smoke and consume a high amount of caffeine,展开更多
The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network（AERONET） for the period from January to December, 2012 over an urban site,Pretoria（PTR; 25.75°S, 28.28°E, 1449...The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network（AERONET） for the period from January to December, 2012 over an urban site,Pretoria（PTR; 25.75°S, 28.28°E, 1449 m above sea level）, South Africa. We found that monthly mean aerosol optical depth（AOD, τa） exhibits two maxima that occurred in summer（February） and winter（August） having values of 0.36 ± 0.19 and 0.25 ± 0.14,respectively, high-to-moderate values in spring and thereafter, decreases from autumn with a minima in early winter（June） 0.12 ± 0.07. The Angstrom exponents（α440–870） likewise,have its peak in summer（January） 1.70 ± 0.21 and lowest in early winter（June） 1.38 ± 0.26,while the columnar water vapor（CWV） followed AOD pattern with high values（summer） at the beginning of the year（February, 2.10 ± 0.37 cm） and low values（winter） in the middle of the year（July, 0.66 ± 0.21 cm）. The volume size distribution（VSD） in the fine-mode is higher in the summer and spring seasons, whereas in the coarse mode the VSD is higher in the winter and lower in the summer due to the hygroscopic growth of aerosol particles.The single scattering albedo（SSA） ranged from 0.85 to 0.96 at 440 nm over PTR for the entire study period. The averaged aerosol radiative forcing（ARF） computed using SBDART model at the top of the atmosphere（TOA） was- 8.78 ± 3.1 W/m2, while at the surface it was- 25.69 ± 8.1 W/m2 leading to an atmospheric forcing of ＋ 16.91 ± 6.8 W/m2, indicating significant heating of the atmosphere with a mean of 0.47 K/day.展开更多
Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species we...Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species weeds growing in its surroundings. The study consisted of two treatments (Tithonia diversifolia infested and Non-Tithonia diversifolia infested soils) and from the two media, the growth of A. hispidium, B. pilosa E. heterophylla, P. maximum and P. polystachion was significantly affected in soil infested by T. diversifolia. The number of weed seedling emergence afore mentioned was significantly lower than what was obtained in soil not infested with T. diversifolia and this accounted for about 38% of the tested weed species. Germination of four of these weeds species (23%) (A. spinosus, C. viscosa, T. procumbens and D. gayana) was enhanced by the presence of T. diversifolia. The study further revealed that weed counts in T. diversifolia infested soil is significantly lower than the ones in soil without T. diversifolia infestation. Likewise, the vegetative growth of some species (A. spinosus, C. viscosa, T. procumbens and D. gayana) was improved in this soil. This shows that T. diversifolia infested soil contains allelochemicals that performed both stimulatory and inhibitory functions.展开更多
Flow assurance has been a major challenge in petroleum production systems especially in offshore operations where severe slugging is a dominant aching issue.This is characterized by pulsating flow behavior which impac...Flow assurance has been a major challenge in petroleum production systems especially in offshore operations where severe slugging is a dominant aching issue.This is characterized by pulsating flow behavior which impacts the reservoir productivity,pipeline-riser systems,and surface facilities(separator).The only means so far,of delivering reservoir fluids from offshore wells to the separator at the surface is by pipeline-riser systems where slugging is most prominent and oftentimes unavoidable.Though passive and active measures have been deployed over time to mitigate the associated problem,there is the need to develop a predictive tool for mitigating offshore slugging in the riser system.This study involves the use of a model and analysis approach to eliminate severe slugging based on the balance of forces acting on the pipeline-riser system.Modified stability criteria which consider accumulation and frictional pressure drops have been developed.The current approach is solely physicsdriven,to predict the corresponding liquid and gas velocities at which the fluctuations would be severe when producing multiphase fluids through pipeline-riser systems.By balancing the forces acting on a riser-pipeline system and accounting for frictional and accumulation effects,two hydraulic flow modeling approaches have been used in this study to improve the criteria for predicting the condition of severe slugging.The developed criteria were computed using MATLAB/Simulink and a severe slugging flow map was generated.The“new study 1”and“new study 2”showed a 16%and 13%increase respectively in predicted unstable cases than the Malekzadeh criteria.The criteria were tested at different separator pressures.The Taitel and Jansen criteria could not predict severe slugging at elevated separator pressure.Notwithstanding,the developed flow maps using the“new study 1”are more reliable than the“new study 2”.This is because the“new study 2”approach over defines the physics of severe slugging.The criteria were also tested at v展开更多
CAPTCHA is an acronym that stands for Completely Automated Public Turing Test to tell Computers and Humans Apart(CAPTCHA),it is a good example of an authentication system that can be used to determine the true identit...CAPTCHA is an acronym that stands for Completely Automated Public Turing Test to tell Computers and Humans Apart(CAPTCHA),it is a good example of an authentication system that can be used to determine the true identity of any user.It serves as a security measure to prevent an attack caused by web bots(automatic programs)during an online transaction.It can come as text-based or image-based depending on the project and the programmer.The usability and robustness,as well as level of security,provided each of the varies and call for the development of an improved system.Hence,this paper studied and improved two different CAPTCHA systems(the text-based CAPTCHA and image-based CAPTCHA).The textbased and image-based CAPTCHAwere designed using JavaScript.Response time and solving time are the two metrics used to determine the effectiveness and efficiency of the two CAPTCHA systems.The inclusion of response time and solving time improved the shortfall of the usability and robustness of the existing system.The developed system was tested using 200 students from the Federal College of Animal Health and Production Technology.The results of each of the participants,for the two CAPTCHAs,were extracted from the database and subjected to analysis using SPSS.The result shows that textbased CAPTCHAhas the lowest average solving time(21.3333 s)with a 47.8%success rate while image-based CAPTCHA has the highest average solving time was 23.5138 s with a 52.8%success rate.The average response time for the image-based CAPTCHA was 2.1855 s with a 37.9%success rate lower than the text-based CAPTCHA response time(3.5561 s)with a 62.1%success rate.This indicates that the text-based CAPTCHA is more effective in terms of usability tests while image-based CAPTCHA is more efficient in terms of system responsiveness and recommended for potential users.展开更多
One of the major constraints of wireless sensor networks is limited energy available to sensor nodes because of the small size of the batteries they use as source of power. Clustering is one of the routing techniques ...One of the major constraints of wireless sensor networks is limited energy available to sensor nodes because of the small size of the batteries they use as source of power. Clustering is one of the routing techniques that have been using to minimize sensor nodes’ energy consumption during operation. In this paper, A Novel Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks (ANCAEE) has been proposed. The algorithm achieves good performance in terms of minimizing energy consumption during data transmission and energy consumptions are distributed uniformly among all nodes. ANCAEE uses a new method of clusters formation and election of cluster heads. The algorithm ensures that a node transmits its data to the cluster head with a single hop transmission and cluster heads forward their data to the base station with multi-hop transmissions. Simulation results show that our approach consumes less energy and effectively extends network utilization.展开更多
The present work intended to develop an invert emulsion drilling mud from biodegradable neem seed oil as an alternative to conventional diesel-based drilling mud.This would present comparable properties and performanc...The present work intended to develop an invert emulsion drilling mud from biodegradable neem seed oil as an alternative to conventional diesel-based drilling mud.This would present comparable properties and performances with API standard requirements,ecologically friendly and at a low cost.Biodiesel produced from non-edible neem oil was used as the continuous phase in an invert emulsion-based drilling mud.Different tests to investigate the applicability of the mud for drilling applications were conducted.The rheological and lubricity tests results indicate that the neem oil biodiesel-based drilling muds are comparable with conventional diesel-based drilling muds.The produced biodiesel shows a significantly better flash point of 168℃ than the traditional diesel flash point of 70℃;indicating better fire safety than the conventional diesel.The lubricity and rheological data indicate the formulated mud with neem seed oil biodiesel fair reasonably well with conventional diesel and within the API requirements.In general,the preliminary results show that neem oil biodiesel is a potential alternative to conventional organic oil in formulating oil-based drilling mud in terms of technical and environmental analysis.展开更多
文摘Objective To assess perception and level of proper utilization of emergency contraception （EC） among female undergraduates. Methods Cross-sectional questionnaire study was performed on 383 female undergraduates in Nigeria in June 2006. Data analysis was with Z-square test and logistic regressions （P 〈O. 05）. Results One hundred and five （48.2%） had been sexually exposed. Only 32 （30.5%） used regular contraception. Seventy-three （24.3%）female undergraduates were aware of EC. Only 29 （7.6%） had used EC before. Most would not use emergency contraceptive drugs in future due to lack of awareness （64.8%）, and fear for future fertility and of drugs being injurious to health. Use of EC was associated with awareness of correct interval for use （OR=9.1; 95%CI： 2.1-39.9）. Conclusion There is poor knowledge about EC and poor use, while significant need remains. Most knowledge was acquired from peers and inaccurate. Peer educators are important and professionals＇ knowledge needs improvement.
基金supported by Specialty Crops Research Initiative Award 2022-51181-38325 from the USDA National Institute of Food and Agriculture and Hatch Projects 1008680 and 1017286.
文摘Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not considered biodegradable or compostable can take several hundred years to degrade.Each year in the United States,only 9%of overall plastic waste is recycled while 79%is accumulated in landfills or the natural environment.Recycling of plastic mulch is especially constrained due to the contamination that results from their use in farming.Currently,recovered mulches are reported to have 30%–80%surface contamination,primarily from soil and plant debris.Plastic mulch waste is concentrated in areas where they are used and can provide logistical opportunities to the plastic recycling industries.Plastic recycling includes mechanical,advanced(chemical and thermal),and biological methods,that may all be used for polyethylene(PE).Most plastic is recycled using the mechanical method,while advanced and biological methods are promising but face significant financial and technical challenges.For all recycling methods,strategies are needed for managing surface contamination to realize the recycling potential of plastic mulch.
文摘Open burning of municipal solid waste(MSW)is a common practice in Nigeria.Emission of compounds of polycyclic aromatic hydrocarbon(PAHs)in ambient air and ash residues from burning of these wastes pose a great danger to the environment.This study investigated the contribution of open burning of MSW to the levels of PAHs in ambient air and ash residues from the burning site.Ash samples were obtained from six sampling locations at a MSW burning site.Polyurethane foam passive samplers were used in collecting ambient air samples.Quantification of PAHs was carried out using GC-MS operated in selected ion monitoring mode.The trend of ambient concentration of PAHs was;ΣPAHs AS-A(4.023)>AS-B(3.798)>AS-D(3.468)>AS-C(3.288),while average concentration of PAHs in the ash was 6.12 mg/kg.Concentrations of PAHs in ash samples ranged from 5.69-6.34 mg/kg.Principal component analysis(PCA)showed that most of the PAHs in the ambient were from MSW combustion.The results obtained suggest that concerted effort of the government and the relevant stakeholders is required to safeguard the environment and humans from PAH pollution from open burning of MSW.
文摘Background: COVID-19 is a disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Epidemiological data indicated that bacterial complications in COVID-19 would decrease clearance rate of the infecting agent and increase mortality rate. Macrolides such as Azithromycin are usually administered to COVID-19 patients as palliative treatments. Currently, a considerable number of bacterial strains have developed resistance to various antibiotics, especially macrolides. Resistance is reported to be due to possession of mefA, ermB, and mphA genes by Gram positive and Gram negative bacteria. Therefore, this study determined antibiotic resistance patterns and identify mefA, ermB and mphA macrolide-resistant genes in bacterial pathogens isolated from COVID-19 cases in Ibadan, Nigeria. Methods: 400 Nasopharyngeal samples were collected from symptomatic cases before antibiotic medication;structured questionnaires were administered to collect socio-demographic data of participants. Samples were cultured on Blood, Chocolate, MacConkey and Mannitol salt agar at 37°C for 48 hrs. Bacterial identification was performed using VITEK 2.0 ID cards and API 20E for Gram positive and negative bacteria respectively. Antibiotic Susceptibility Testing was performed using Kirby Bauer disc diffusion methods and VITEK 2.0 AST card kits. DNA of multidrug resistant bacterial isolates was extracted;resistant genes were determined using a polymerase chain reaction with specific primers. Amplified genes were detected using agarose gel electrophoresis. Results: 240 (60%) had bacterial growth and 97 (22.2%) yielded no growth. From the 240 bacterial isolates, 38 (15.83%) were multi-drug resistant including resistance to macrolides (Azithromycin) 20 (52.63%) of which were positive for either mefA or ermB, and none (0.0%) possess mphA gene;14 (36.8%) isolates had mefA gene, 10 (26.3%) isolates carried ermB gene. Conclusion: Multi-drug bacterial resistance including macrolides and quinolones was detected. Only mefA and ermB genes w
文摘This study deals with the physico-chemical, mineralogical and geotechnical characterization of alluvial clays from Batchenga in Cameroon with a view to their use as building materials for housing. The alluvial clay (Arg.All) was collected in the locality of Batchenga at the village Natchigal (4˚20'40''N and 11˚37'40''E at 378 m altitude) and was fired between 900˚C and 1100˚C. Characterization was performed by XRD, XRF, DTA/DTG, and firing tests. XRD, XRF, DTA/DTG infrared analysis methods were performed on these clays. The linear shrinkage, mechanical strengths, water absorption, porosity and density were measured on the fired products. The results obtained show that the major oxides are for the Arg.Lat SiO<sub>2</sub> (72.13%), Al<sub>2</sub>O<sub>3 </sub>(14.1%), Fe<sub>2</sub>O<sub>3</sub> (4.45%) and for the Arg.All: SiO<sub>2</sub> (48.91%), Al<sub>2</sub>O<sub>3</sub> (23.79%), Fe<sub>2</sub>O<sub>3</sub> (9.54%). The fired products based on alluvial clay, present the flexural strength of 4.45 MPa at 900˚C and 6.80 MPa at 1100˚C. As for those based on lateritic clay, the flexural strength is 0.53 and 0.76 MPa respectively at 900 and 1100˚C. The porosity is 33.69% at 900˚C and 22.93% at 1100˚C for the alluvial clay and 39.55% at 900˚C and 36.01% for the lateritic clay at 1100˚C. Water absorption is 18% to 11.16% for alluvial clay and 22.43% to 21.16% for lateritic clay at 900˚C and 1100˚C respectively. These results suggest that alluvial clay and its firing products have better physico-chemical, geotechnical and mechanical characteristics regardless of the firing temperature of the manufactured products. The addition of degreaser is recommended to improve the mechanical performance of lateritic clay.
文摘The musculo-skeletal system is commonly affected in sickle cell disease, manifesting itself as bone infarction, femoral head osteonecrosis, osteomyelitis, myonecrosis, myofibrosis and fascitis. Myositis and fasciitis are observed during a vaso-occlusive crisis in 4% of patients. Pain and swelling of bilateral proximal groups of muscles of upper and lower limbs are common presenting complaints due to prolonged sickling crises [1]. We report a case of 30-year old known HbSS patient with bilateral knee stiffness of two months duration, with associated swelling and warmth of both thighs. No preceding history of trauma. He was said to suffer at least two sickling crises in a month with the last one occurring one week prior to presentation. X-ray of the thigh showed no calcification in muscle groups. He was commenced on flexion-extension exercises.
文摘Emulsions are difficult to transport in the oil and gas industry due to its water content and high viscosity property, thus a need arises to break these emulsions down into lighter emulsions that would make it a lot more suitable for transportation. In this research, biodiesel was synthesized and used to break down relatively viscous emulsion samples into lighter emulsion samples. An apparatus was designed with the aim of determining the flowrate of four different samples in different proportions and compositions: 80% oil and 20% water (sample A), 90% sample A + 10% of biodiesel by volume (sample B), 75% of sample A + 25% of biodiesel by volume (sample C), 60% of sample A + 40% biodiesel by volume (sample D). The results showed that it was possible to significantly increase the flow of emulsions by injecting biodiesel, which was acted as a surfactant, resulting in the lowering of the surface tension of the emulsion sample. The relevance of this research work is validated as it proffers a solution to the transportation of heavy oil and emulsions from all over the world possessing the non-Newtonian flow behavior, which results in serious problems related to its transportation.
文摘BACKGROUND Unexplained infertility(UI)is usually used for any heterosexual couple who failed to have a successful clinical pregnancy without identifying clear causes after they undergo all standard fertility tests.Evidence shows that leptin is one of the most accurate biomarkers for UI.Nevertheless,conflicting results regarding leptin levels in women with UI have been reported.AIM To find the serum leptin levels in women with UI.METHODS All studies written in English and conducted before April 30,2021 from PubMed/MEDLINE,Embase,Cochrane Central Register of Controlled Trials,ClinicalTrials.gov,Google Scholar,OpenGrey,OATD,and the infertility conference abstract were included.Studies were found eligible if they provided the mean and standard deviation of leptin for the case group and control group.The quality assessment of individual studies was evaluated using the Joanna Briggs Institute Quality Assessment Tool.Data synthesis and statistical analysis were done using STATA software version 16.RESULTS A total of 378 studies were reviewed,and just six studies that fulfilled the eligibility criteria were included in this meta-analysis.The pooled result showed that leptin levels were significantly higher in women with UI compared to fertile women,with a standardized mean difference of 0.97(95%confidence interval:-0.49-2.43).However,heterogeneity across studies was highly significant(P<0.00001;I2=98.8%).CONCLUSION The results of this study suggest that leptin levels are elevated in women with UI compared with fertile women;hence,leptin could be a potential biomarker for UI in women,and it may be useful for identifying women with a high risk of infertility.
文摘The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review presents the various dynamics of oil spill, conventional clean-up technologies and silica aerogel synthesis techniques. It also highlights some investigations of oil spill sorption using aerogels. The future prospect of rice husk as a cheaper source silica aerogel is also considered.
文摘The effect of crude oil pollution on heavy metal content in the soil, microbial population, and growth performance of maize and cowpea was investigated. The heavy metals determined were lead, cadmium, iron, nickel, zinc and copper. Microbial population and growth performance of maize and cowpea in both polluted and unpolluted soils samples were evaluated. Results showed that higher concentration of heavy metals was observed in all crops planted in polluted soil, polluted site vegetation and soils. The total heterotrophic bacteria was 89% lower in the polluted soil than in the unpolluted soil while fungi was 78% lower in the polluted soil when compared to the unpolluted soil. However, hydrocarbon utilizing bacteria and fungi was 22% and 24% higher in the polluted soil than in the unpolluted soil respectively. Maize and Cowpea performed poorly in polluted soil when compared with unpolluted soil as evidenced in the growth parameters measured for both crops.
文摘The petroleum paleo-productivity and generative potential of the Nkporo and Awgu shales in the Lower Benue Trough (LBT) were studied. Major oxides were determined using Spectro Ciros Inductively-coupled plasma optical emission spectrometer (ICP-OES) while trace and rare earth elements were determined using an ELAN 9000 Inductively-coupled plasma mass spectrometer (ICP-MS). The shales have Co/Ni ratios greater than 0.1 suggesting oil source rocks with more marine source input due to brief marine incursion in the transition zone after deposition. The very low Ni values and moderate V values, and a lack of correlation between the TOC and sulphur content, suggests that the organic matter is of terrestrial Type Ⅲ;and the very low paleo-productivity (Ba/Al and P/Ti ratios) suggests that the organic matter is of terrestrial origin. The low V/Ni values of the Nkporo and Awgu shales (Av. ≈ 4) and the high metal concentrations indicate a matured status. From the K/Rb ratios of the Nkporo (191–259) and Awgu shales (198–261), it can be deduced that the organic matter within the shales experienced a considerable loss of K and the shales are mature to generate gaseous hydrocarbons.
文摘BACKGROUND Female infertility with unknown causes(unexplained)remains one of the mysteries in the reproductive health field,where the diagnostic evidence is still weak and the proposed treatments still work with unknown methods.However,several studies have proposed some possible causes and risk factors for unexplained female infertility.AIM To characterize and identify factors associated with unexplained infertility in Sudanese women.METHODS A matched(age and body mass index)case-control study was conducted from March 2021 to February 2022.The study samples were 210 women with unexplained infertility(UI)and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum,Sudan.The risk factors of unexplained infertility were identified using a structured,pretested questionnaire containing information on socio-demographic variables,anthropometrics,clinical diagnosis of infertility,behavioral factors,physical activity assessment,diversity,and consumption of different food groups by the study participants.RESULTS The results showed a higher proportion of women diagnosed with UI were residents of rural areas than controls(21.4%vs 11.1%,P<0.05),and previous miscarriages and/or abortions were more common in fertile women compared with infertile women(13.16%vs 5.71%,P<0.05).Additionally,infertile women had a significantly(P<0.05)higher proportion of family history of infertility(explained and unexplained)compared with controls.Finally,after controlling for the effects of potentially confounding variables using multivariable logistic regression analysis,only marital status,family history of infertility,use of modern contraceptives,smoking,caffeine consumption,physical activity level,meals consumed,other vitamin-A-rich fruits and vegetables,and other vegetables were found to be significant(P<0.05)factors associated with unexplained infertility among Sudanese women.CONCLUSION Married women with a family history of infertility who smoke and consume a high amount of caffeine,
基金supported through Africa Laser Centre (Pretoria) collaborative projectfunded NRF bi-lateral project(Grand UID:78682)
文摘The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network（AERONET） for the period from January to December, 2012 over an urban site,Pretoria（PTR; 25.75°S, 28.28°E, 1449 m above sea level）, South Africa. We found that monthly mean aerosol optical depth（AOD, τa） exhibits two maxima that occurred in summer（February） and winter（August） having values of 0.36 ± 0.19 and 0.25 ± 0.14,respectively, high-to-moderate values in spring and thereafter, decreases from autumn with a minima in early winter（June） 0.12 ± 0.07. The Angstrom exponents（α440–870） likewise,have its peak in summer（January） 1.70 ± 0.21 and lowest in early winter（June） 1.38 ± 0.26,while the columnar water vapor（CWV） followed AOD pattern with high values（summer） at the beginning of the year（February, 2.10 ± 0.37 cm） and low values（winter） in the middle of the year（July, 0.66 ± 0.21 cm）. The volume size distribution（VSD） in the fine-mode is higher in the summer and spring seasons, whereas in the coarse mode the VSD is higher in the winter and lower in the summer due to the hygroscopic growth of aerosol particles.The single scattering albedo（SSA） ranged from 0.85 to 0.96 at 440 nm over PTR for the entire study period. The averaged aerosol radiative forcing（ARF） computed using SBDART model at the top of the atmosphere（TOA） was- 8.78 ± 3.1 W/m2, while at the surface it was- 25.69 ± 8.1 W/m2 leading to an atmospheric forcing of ＋ 16.91 ± 6.8 W/m2, indicating significant heating of the atmosphere with a mean of 0.47 K/day.
文摘Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species weeds growing in its surroundings. The study consisted of two treatments (Tithonia diversifolia infested and Non-Tithonia diversifolia infested soils) and from the two media, the growth of A. hispidium, B. pilosa E. heterophylla, P. maximum and P. polystachion was significantly affected in soil infested by T. diversifolia. The number of weed seedling emergence afore mentioned was significantly lower than what was obtained in soil not infested with T. diversifolia and this accounted for about 38% of the tested weed species. Germination of four of these weeds species (23%) (A. spinosus, C. viscosa, T. procumbens and D. gayana) was enhanced by the presence of T. diversifolia. The study further revealed that weed counts in T. diversifolia infested soil is significantly lower than the ones in soil without T. diversifolia infestation. Likewise, the vegetative growth of some species (A. spinosus, C. viscosa, T. procumbens and D. gayana) was improved in this soil. This shows that T. diversifolia infested soil contains allelochemicals that performed both stimulatory and inhibitory functions.
文摘Flow assurance has been a major challenge in petroleum production systems especially in offshore operations where severe slugging is a dominant aching issue.This is characterized by pulsating flow behavior which impacts the reservoir productivity,pipeline-riser systems,and surface facilities(separator).The only means so far,of delivering reservoir fluids from offshore wells to the separator at the surface is by pipeline-riser systems where slugging is most prominent and oftentimes unavoidable.Though passive and active measures have been deployed over time to mitigate the associated problem,there is the need to develop a predictive tool for mitigating offshore slugging in the riser system.This study involves the use of a model and analysis approach to eliminate severe slugging based on the balance of forces acting on the pipeline-riser system.Modified stability criteria which consider accumulation and frictional pressure drops have been developed.The current approach is solely physicsdriven,to predict the corresponding liquid and gas velocities at which the fluctuations would be severe when producing multiphase fluids through pipeline-riser systems.By balancing the forces acting on a riser-pipeline system and accounting for frictional and accumulation effects,two hydraulic flow modeling approaches have been used in this study to improve the criteria for predicting the condition of severe slugging.The developed criteria were computed using MATLAB/Simulink and a severe slugging flow map was generated.The“new study 1”and“new study 2”showed a 16%and 13%increase respectively in predicted unstable cases than the Malekzadeh criteria.The criteria were tested at different separator pressures.The Taitel and Jansen criteria could not predict severe slugging at elevated separator pressure.Notwithstanding,the developed flow maps using the“new study 1”are more reliable than the“new study 2”.This is because the“new study 2”approach over defines the physics of severe slugging.The criteria were also tested at v
文摘CAPTCHA is an acronym that stands for Completely Automated Public Turing Test to tell Computers and Humans Apart(CAPTCHA),it is a good example of an authentication system that can be used to determine the true identity of any user.It serves as a security measure to prevent an attack caused by web bots(automatic programs)during an online transaction.It can come as text-based or image-based depending on the project and the programmer.The usability and robustness,as well as level of security,provided each of the varies and call for the development of an improved system.Hence,this paper studied and improved two different CAPTCHA systems(the text-based CAPTCHA and image-based CAPTCHA).The textbased and image-based CAPTCHAwere designed using JavaScript.Response time and solving time are the two metrics used to determine the effectiveness and efficiency of the two CAPTCHA systems.The inclusion of response time and solving time improved the shortfall of the usability and robustness of the existing system.The developed system was tested using 200 students from the Federal College of Animal Health and Production Technology.The results of each of the participants,for the two CAPTCHAs,were extracted from the database and subjected to analysis using SPSS.The result shows that textbased CAPTCHAhas the lowest average solving time(21.3333 s)with a 47.8%success rate while image-based CAPTCHA has the highest average solving time was 23.5138 s with a 52.8%success rate.The average response time for the image-based CAPTCHA was 2.1855 s with a 37.9%success rate lower than the text-based CAPTCHA response time(3.5561 s)with a 62.1%success rate.This indicates that the text-based CAPTCHA is more effective in terms of usability tests while image-based CAPTCHA is more efficient in terms of system responsiveness and recommended for potential users.
文摘One of the major constraints of wireless sensor networks is limited energy available to sensor nodes because of the small size of the batteries they use as source of power. Clustering is one of the routing techniques that have been using to minimize sensor nodes’ energy consumption during operation. In this paper, A Novel Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks (ANCAEE) has been proposed. The algorithm achieves good performance in terms of minimizing energy consumption during data transmission and energy consumptions are distributed uniformly among all nodes. ANCAEE uses a new method of clusters formation and election of cluster heads. The algorithm ensures that a node transmits its data to the cluster head with a single hop transmission and cluster heads forward their data to the base station with multi-hop transmissions. Simulation results show that our approach consumes less energy and effectively extends network utilization.
文摘The present work intended to develop an invert emulsion drilling mud from biodegradable neem seed oil as an alternative to conventional diesel-based drilling mud.This would present comparable properties and performances with API standard requirements,ecologically friendly and at a low cost.Biodiesel produced from non-edible neem oil was used as the continuous phase in an invert emulsion-based drilling mud.Different tests to investigate the applicability of the mud for drilling applications were conducted.The rheological and lubricity tests results indicate that the neem oil biodiesel-based drilling muds are comparable with conventional diesel-based drilling muds.The produced biodiesel shows a significantly better flash point of 168℃ than the traditional diesel flash point of 70℃;indicating better fire safety than the conventional diesel.The lubricity and rheological data indicate the formulated mud with neem seed oil biodiesel fair reasonably well with conventional diesel and within the API requirements.In general,the preliminary results show that neem oil biodiesel is a potential alternative to conventional organic oil in formulating oil-based drilling mud in terms of technical and environmental analysis.
