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Assessing the Impact of Gold Mining on the Quality of Water Resources in the Commune of Meguet, Burkina Faso

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Journal of Water Resource and Protection 2024年第4期16卷 281-292页

作者： Issoufou Ouedraogo samuel Lankoande Yacouba Konate Boukary Sawadogo Nicolas Kagambega Martin Lompo Higher School of engineering (ESI) University of Fada N&#8217Gourma Fada N&#8217Gourma Burkina Faso Geosciences and environment Laboratory (LaGE) Joseph KI-ZERBO University Ouagadougou Burkina Faso Water Hydro-Systems and Agriculture Laboratory (LEHSA) International Institute of Water and Environmental Engineering (2iE) Ouagadougou Burkina Faso

Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant impact on the environment due to inappropriate practices and the use of various chemical substances. This study aims to assess the impact of artisanal gold mining on the quality of water resources in a rural community at Méguet, Burkina Faso. To this end, surface and groundwater samples were collected and analyzed at the BUMIGEB laboratory. Field results show that the waters are slightly alkaline (6.97 enerally deviating from the levels recommended by WHO guidelines for Burkina Faso. Trace metals contamination of water resources in the commune of Méguet is mainly due to Fe (3.78 - 11.12 mg/kg), Hg (0.03 - 0.29 mg/kg), As (0.01- 6.31 mg/kg) and Pb (0.01 - 3.8 mg/kg). This study can serve as a basis for guiding national environmental policies to protect the water resources of the Méguet mine.

关键词： Gold Panning Water Quality Trace Metal Méguet Burkina Faso

Modelling the Survival of Western Honey Bee Apis mellifera and the African Stingless Bee Meliponula ferruginea Using Semiparametric Marginal Proportional Hazards Mixture Cure Model

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Journal of Data Analysis and Information Processing 2024年第1期12卷 24-39页

作者： Patience Isiaho Daisy Salifu samuel Mwalili Henri E. Z. Tonnang Department of Statistics and Actuarial Sciences Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya Data Management Modelling and Geo-Information Unit International Centre of Insect Physiology and Ecology (icipe) Nairobi Kenya

Classical survival analysis assumes all subjects will experience the event of interest, but in some cases, a portion of the population may never encounter the event. These survival methods further assume independent survival times, which is not valid for honey bees, which live in nests. The study introduces a semi-parametric marginal proportional hazards mixture cure (PHMC) model with exchangeable correlation structure, using generalized estimating equations for survival data analysis. The model was tested on clustered right-censored bees survival data with a cured fraction, where two bee species were subjected to different entomopathogens to test the effect of the entomopathogens on the survival of the bee species. The Expectation-Solution algorithm is used to estimate the parameters. The study notes a weak positive association between cure statuses (ρ1=0.0007) and survival times for uncured bees (ρ2=0.0890), emphasizing their importance. The odds of being uncured for A. mellifera is higher than the odds for species M. ferruginea. The bee species, A. mellifera are more susceptible to entomopathogens icipe 7, icipe 20, and icipe 69. The Cox-Snell residuals show that the proposed semiparametric PH model generally fits the data well as compared to model that assume independent correlation structure. Thus, the semi parametric marginal proportional hazards mixture cure is parsimonious model for correlated bees survival data.

关键词： Mixture Cure Models Clustered Survival Data Correlation Structure Cox-Snell Residuals EM Algorithm Expectation-Solution Algorithm

Comparison of Semi-Parametric Shared Frailty Models for Bees’Survival

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Journal of Data Analysis and Information Processing 2024年第2期12卷 267-288页

Survival analysis is a fundamental tool in medical science for time-to-event data. However, its application to colony organisms like bees poses challenges due to their social nature. Traditional survival models may not accurately capture the interdependence among individuals within a colony. Frailty models, accounting for shared risks within groups, offer a promising alternative. This study evaluates the performance of semi-parametric shared frailty models (gamma, inverse normal, and positive stable-in comparison to the traditional Cox model using bees’ survival data). We examined the effect of misspecification of the frailty distribution on regression and heterogeneity parameters using simulation and concluded that the heterogeneity parameter was more sensitive to misspecification of the frailty distribution and choice of initial parameters (cluster size and true heterogeneity parameter) compared to the regression parameter. From the data, parameter estimates for covariates were close for the four models but slightly higher for the Cox model. The shared gamma frailty model provided a better fit to the data in comparison with the other models. Therefore, when focusing on regression parameters, the gamma frailty model is recommended. This research underscores the importance of tailored survival methodologies for accurately analyzing time-to-event data in social organisms.

关键词： Correlated Failure Times Frailty Survival Analysis Unobserved Heterogeneity

Investigation of Acoustomagnetoelectric Effect in Bandgap Graphene by the Boltzmann Transport Equation

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World Journal of Condensed Matter Physics 2024年第1期14卷 10-20页

作者： Raymond Edziah samuel S. Bentsiefi Kwadwo Dompreh Anthony Twum Emmanuel Kofi Amewode Patrick Mensah-Amoah Ebenezer T. Tatchie Cynthia Jebuni-Adanu samuel Y. Mensah Department of Physics University of Cape Coast Cape Coast Ghana Department of Physics Education University of Education Winneba Ghana

We study the acoustomagnetoelectric (AME) effect in two-dimensional graphene with an energy bandgap using the semiclassical Boltzmann transport equation within the hypersound regime, (where represents the acoustic wavenumber and is the mean free path of the electron). The Boltzmann transport equation and other relevant equations were solved analytically to obtain an expression for the AME current density, consisting of longitudinal and Hall components. Our numerical results indicate that both components of the AME current densities display oscillatory behaviour. Furthermore, geometric resonances and Weiss oscillations were each defined using the relationship between the current density and Surface Acoustic Wave (SAW) frequency and the inverse of the applied magnetic field, respectively. Our results show that the AME current density of bandgap graphene, which can be controlled to suit a particular electronic device application, is smaller than that of (gapless) graphene and is therefore, more suited for nanophotonic device applications.

关键词： Boltzmann Transport Equation Acoustomagnetoelctric Effect Surface Acoustic Wave Gapless Graphene Weiss Oscillations

A prospective cohort of men with localized prostate cancer on active surveillance protocol in Hong Kong,China:what did we learn?

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Asian Journal of Andrology 2024年第3期26卷 245-249页

作者： Xiaobo Wu Ivan Ching-Ho Ko Cindy Yeuk-Lam Hong samuel Chi-Hang Yee Jeremy Yuen-Chun Teoh Samson Yun-Sang Chan Ho-Man Tam Chi-Kwok Chan Chi-Fai Ng Peter Ka-Fung Chiu SH Ho Urology Centre Department of SurgeryFaculty of MedicineThe Chinese University of Hong KongHong KongChina

This study aimed to report the outcomes of active surveillance(AS)in the management of low-risk prostate cancer(PCa).It recruited87 men who were prospectively followed up according to the Prostate Cancer Research International Active Surveillance(PRIAS)protocol with local adaptation at SH Ho Urology Centre,Prince of Wales Hospital,Hong Kong,*** investigated the predictorsof disease progression and found that baseline prostate-specific antigen density(PSAD)and the presence of the highest ProstateImaging-Reporting and Data System(PI-RADS)score 5 lesion on magnetic resonance imaging(MRI)are significantly correlatedwith disease ***,men with PSAD>0.2 ng ml^(−2)or PI-RADS 4 or 5 lesions had significantly worse upgradingfree survival compared to those with PSAD≤0.2 ng ml−2 and PI-RADS 2 or 3 *** study concludes that AS is a safe andeffective management strategy for selected patients to defer radical treatment and that most disease progression can be detectedafter the first repeated *** combination of PSAD>0.2 ng ml^(−2)and PI-RADS 4 or 5 lesions may serve as a useful predictorof early disease progression and provide a guide to optimize follow-up protocols for men in different risk groups.

关键词： active surveillance cohort localized prostate cancer

New avenues for the treatment of immunotherapy-resistant pancreatic cancer

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1134-1153页

作者： Luis Guilherme de Oliveira Silva Fabian Fellipe Bueno Lemos Marcel Silva Luz samuel Luca Rocha Pinheiro Mariana dos Santos Calmon Gabriel Lima Correa Santos Gabriel Reis Rocha Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil

Pancreatic cancer(PC)is characterized by its extremely aggressive nature and ranks 14th in the number of new cancer cases ***,due to its complexity,it ranks 7th in the list of the most lethal cancers *** pathogenesis of PC involves several complex processes,including familial genetic factors associated with risk factors such as obesity,diabetes mellitus,chronic pancreatitis,and *** in genes such as KRAS,TP53,and SMAD4 are linked to the appearance of malignant cells that generate pancreatic lesions and,consequently,*** this context,some therapies are used for PC,one of which is immunotherapy,which is extremely promising in various other types of cancer but has shown little response in the treatment of PC due to various resistance mechanisms that contribute to a drop in immunotherapy *** is therefore clear that the tumor microenvironment(TME)has a huge impact on the resistance process,since cellular and non-cellular elements create an immunosuppressive environment,characterized by a dense desmoplastic stroma with cancerassociated fibroblasts,pancreatic stellate cells,extracellular matrix,and immunosuppressive *** to this are genetic mutations in TP53 and immunosuppressive factors that act on T cells,resulting in a shortage of CD8+T cells and limited expression of activation markers such as *** this way,finding new strategies that make it possible to manipulate resistance mechanisms is ***,techniques such as the use of TME modulators that block receptors and stromal molecules that generate resistance,the use of genetic manipulation in specific regions,such as microRNAs,the modulation of extrinsic and intrinsic factors associated with T cells,and,above all,therapeutic models that combine these modulation techniques constitute the promising future of PC ***,this study aims to elucidate the main mechanisms of resistance to immunotherapy in PC and new ways of manipulating thi

关键词： Pancreatic cancer Immunotherapy Resistance Tumor microenvironment manipulation Combined immunotherapy

Beta-HCG Levels and Ovarian Ultrasonography Results among Non-Pregnant Women of Reproductive Age in Port Harcourt, Nigeria: A Cross-Sectional Study

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Journal of Biosciences and Medicines 2024年第5期12卷 233-241页

作者： Celine C. Agonsi Francis Anacletus Joel Aluko Chinemerem Eleke Joy C. samuel African Centre of Public Health and Toxicological Research (ACE-PUTOR) University of Port Harcourt Choba Nigeria Department of Nursing Science University of Port Harcourt Choba Nigeria

Background: Certain ovarian cancers that were previously common in postmenopausal women are now increasingly observed in women of reproductive age. The research on using β-HCG as a diagnostic biomarker for ovarian cancer in women of reproductive age is ongoing. Aim: This study assessed the level of serum β-HCG in non-pregnant women of reproductive age and determined its potential association with suspicious ovarian ultrasonography results. Methods: The study was conducted in Port Harcourt, Nigeria. This study adopted a cross-sectional design on a quota sample of 224 case notes of women aged 18 - 40 years obtained from eight diagnostic centres. A data extraction form was used for data collection. Data analysis employed descriptive statistics, Chi-square, Fisher’s exact test, and Odds Ratio at 95% confidence and 5% significance levels. Results: About 5.8% of the participants exhibited detectable levels of serum β-HCG above 5 IU/L (World Health Organization reference) at a mean concentration of 5.87 (±1.75) IU/L. About 4.0% of the participants had suspicious ovarian lesions identified through ultrasonography. Participants with elevated serum β-HCG levels above the WHO reference were 59 times more likely to have suspicious ovarian lesions (Odds ratio: 59.4, 95%CI: 12.3 - 287.8, p β-HCG level and age (p = 0.041) as well as parity (p Conclusion: Serum β-HCG levels above the WHO reference in non-pregnant women were associated with suspicious ovarian lesions. More rigorous primary research, systematic reviews, and meta-analyses are needed to confirm the findings of this study.

关键词： Biomarkers Ovarian Cancer Pregnancy Ultrasonography

Characterization and Modeling of Mechanical Properties of Additively Manufactured Coconut Fiber-Reinforced Polypropylene Composites

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Advances in Materials Physics and Chemistry 2024年第6期14卷 95-112页

作者： George Mosi Bernard W. Ikua samuel K. Kabini James W. Mwangi Department of Mechatronic engineering Jomo Kenyatta University of Agriculture and Technology Juja Kenya

In the face of the increased global campaign to minimize the emission of greenhouse gases and the need for sustainability in manufacturing, there is a great deal of research focusing on environmentally benign and renewable materials as a substitute for synthetic and petroleum-based products. Natural fiber-reinforced polymeric composites have recently been proposed as a viable alternative to synthetic materials. The current work investigates the suitability of coconut fiber-reinforced polypropylene as a structural material. The coconut fiber-reinforced polypropylene composites were developed. Samples of coconut fiber/polypropylene (PP) composites were prepared using Fused Filament Fabrication (FFF). Tests were then conducted on the mechanical properties of the composites for different proportions of coconut fibers. The results obtained indicate that the composites loaded with 2 wt% exhibited the highest tensile and flexural strength, while the ones loaded with 3 wt% had the highest compression strength. The ultimate tensile and flexural strength at 2 wt% were determined to be 34.13 MPa and 70.47 MPa respectively. The compression strength at 3 wt% was found to be 37.88 MPa. Compared to pure polypropylene, the addition of coconut fibers increased the tensile, flexural, and compression strength of the composite. In the study, an artificial neural network model was proposed to predict the mechanical properties of polymeric composites based on the proportion of fibers. The model was found to predict data with high accuracy.

关键词： Additive Manufacturing Artificial Neural Network Mechanical Properties Natural Fibers Polypropylene

Cost effectiveness of nonpharmacological prevention programs for diabetes:A systematic review of trial-based studies

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Chronic Diseases and Translational Medicine 2024年第1期10卷 12-21页

作者： Yongyi Xiong Zhaohua Huo samuel Y.S.Wong Benjamin H.K.Yip Jockey Club School of Public Health and Primary Care Prince of Wales HospitalThe Chinese University of Hong KongShatinHong KongChina

Trial-based economic value of prevention programs for diabetes is *** aimed to review the cost-effectiveness of nonpharmacological interventions to prevent type-2 diabetes mellitus(T2DM)for high-risk *** electronic databases were searched up to March *** assessing both the cost and health outcomes of nonpharmacological interventions for people at high-risk of T2DM were *** quality of the study was assessed by the Consolidated Health Economic Evaluation Reporting Standards 2022 *** primary outcome for synthesis was incremental cost-effectiveness ratios(ICER)for quality-adjusted life years(QALYs),and costs were standardized in 2022 US *** synthesis was performed,considering different types and delivery methods of *** studies included five based on the US diabetes prevention program(DPP),six on non-DPP-based lifestyle interventions,four on health education,and one on screening plus lifestyle *** with usual care,lifestyle interventions showed higher potential of cost-effectiveness than educational *** lifestyle interventions,DPP-based programs were less cost-effective(median of ICERs:$27,077/QALY)than non-DPP-based programs(median of ICERs:$1395/QALY)from healthcare perspectives,but with larger decreases in diabetes ***,the cost-effectiveness of interventions was more possibly realized through the combination of different delivery *** interventions to prevent T2DM in high-risk populations are both cost-effective and feasible in various ***,economic evidence from low-and middle-income countries is still lacking,and interventions delivered by trained laypersons and combined with peer support sessions or mobile technologies could be potentially a cost-effective solution in such settings with limited resources.

关键词： economic evaluation nonpharmacological interventions pre-diabetes prevention