In this study, we present different methods of estimating fuzzy reliability of a two-parameter Rayleigh distribution via the maximum likelihood estimator, median first-order statistics estimator, quartile estimator, L-moment estimator, and mixed Thompson-type estimator. The mean-square error MSE as a measurement for comparing the considered methods using simulation through different values for the parameters and unalike sample sizes is used. The results of simulation show that the fuzziness values are better than the real values for all sample sizes, as well as the fuzzy reliability at the estimation of the Maximum

Hepatitis B virus (HBV) is a major global health challenge. Emerging evidence suggests that poor knowledge and stigma are impacting HBV control efforts in sub-Saharan Africa (SSA), however their role is not well understood. We conducted a cross-sectional study of adults aged ≥ 18 years in a community and pharmacy setting in Freetown, Sierra Leone. A structured questionnaire was used to assess knowledge, stigmatizing attitudes, and health-seeking behaviors regarding HBV. Logistic regression was used to identify predictors of HBV knowledge and related stigma. A total of 306 adult participants were enrolled (50.7% male, 7.5% HBV positive and 11.7% vaccinated). Overall, 52.2% had comprehensive HBV knowledge and 49.3% expressed a stigmatizing attitude towards people with HBV. Notwithstanding, 72.2% stated they would receive the HBV vaccine if offered, 80.4% would take anti-HBV medication and 78.8% would be willing to attend clinic regularly. Comprehensive HBV knowledge was associated with HBV positive status (aOR 4.41; p = 0.029) and being vaccinated against HBV (aOR 3.30; p = 0.034). HBV-related stigma was associated with secondary or higher level of education (aOR 2.36; p < 0.001), good HBV knowledge (aOR 2.05; p = 0.006) and pharmacy setting (aOR 1.74, p = 0.037). These findings suggest that education and stigma reduction may benefit HBV elimination efforts in SSA.

This study have uniquely mad use of Box-Jenkins ARIMA models to address the core of the threes objectives set out in view of the focus to add meaningful value to knowledge exploration. The outcome of the research have testify the achievements of this through successful nine months out-of-sample forecasts produced from the program codes, with indicating best model choices from the empirical estimation. In addition, the results also provide description of risks produced from the uncertainty Fan Chart, which clearly outlined possible downside and upside risks to tourist visitations in the country. In the conclusion, it was suggested that downside risks to the low level tourist arrival can be managed through collaboration between authorities concerned with the management of tourist arrivals in the country.

Background: The study aimed to assess the prevalence and correlates of suicidal ideation, plans and attempts among middle school students in Sierra Leone. Method: Data from 2,798 adolescents (15 years of median age) that responded to the cross-sectional “2017 Sierra Leone Global School-Based Student Health Survey (GSHS)” were analysed. Results: The prevalence of past 12-month suicidal ideation was 14.2%, suicide plans 16.0%, and suicide attempts 19.1%. In adjusted logistic regression analysis, worry-induced sleep disturbance (Adjusted Odds Ratio-AOR: 1.84, 95% Confidence Interval-CI: 1.32-2.57), bullied (AOR: 2.90, 95% CI: 1.77-4.74), trouble from alcohol use (AOR: 1.90, 95% CI: 1.03-3.50), and leisure-time sedentary behaviour (AOR: 2.42, 95% CI: 1.18-4.98) were associated with suicidal ideation. Bullied (AOR: 2.40, 95% CI: 1.46-3.95) and current cannabis use (AOR: 2.48, 95% CI: 1.51-4.09) were associated with suicide plans in the past 12 months. No close friends (AOR: 2.63, 95% CI: 1.46-4.72) loneliness (AOR: 1.69, 95% CI: 1.08-2.66), bullied (AOR: 2.33, 95% CI: 1.66-3.28), trouble from alcohol use (AOR: 4.01, 95% CI: 2.25-7.13) and current cannabis use (AOR: 2.93, 95% CI: 1.37-6.25) were positively and school attendance (AOR: 0.62, 95% CI: 0.42-0.92) negatively associated with suicide attempts in the past 12 months. Conclusion: Almost one in five students had made suicide attempts in the past 12 months and several associated variables were discovered that can assist in designing interventions.

Soil above a platinum-group element (PGE)-bearing horizon within the Freetown Layered Intrusion, Sierra Leone contains anomalous concentrations of n-alkanes (CnH2n+2) in the range C14 to C22 not readily attributable to an algal or lacustrine origin. Longer chain n-alkanes (C23 to C31) in the soil were derived from the breakdown of leaf litter beneath the closed canopy humid tropical forest. Spontaneous breakdown of the longer chain n-alkanes to form C14-22 n-alkanes without biogenic or abiogenic catalysts is unlikely as the n-alkanes are stable. In the Freetown soil, the catalytic properties of the PGE (Pt in particular) may lower the temperature at which oxidation of the longer chain n-alkanes can occur. Reaction between these n-alkanes and Pt species such as Pt2+(H2O)2(OH)2 and Pt4+(H2O)2(OH)4 can bend and twist the alkanes, and significantly lower the Heat of Formation. Acknowledging the possibility of microbial catalysis and the difficulty of identifying a direct organic geochemical source of the lighter n-alkanes, this paper explores the theoretical potential for abiogenic Pt species catalysis as a mechanism of breakdown of the longer n-alkanes to form C14-22 alkanes. This novel mechanism could substantiate the presence of the PGE in solution predicted by soil geochemistry and illustrate processes involving the PGE. Graphical Abstract

Bigeye grunt Brachydeuterus auritus is an important economic species in the waters off Sierra Leone in West Africa, with great ecological value. Based on the survey data of bottom trawl nets from 6 voyages from 2019 to 2021, the body weight-length relationship (WLR), as well as their relative fatness, were studied in depth using the method of body length and its corresponding mean body weight. This study fitted the WLR of bigeye grunt by gender, calculated its fullness, and analyzed the influence of environmental factors. The results showed that month and gender had a significant impact on body length and weight distribution (P<0.01). There was a highly significant negative correlation (P<0.01) between the condition factor (a) and the allometric factor (b) in the WLR, and salinity significantly affects b (P<0.05). The (lga)/b ratio was less affected by environmental factors which may be related to the body size and density of the fish. The difference in b between male and female populations was extremely significant (P<0.01). The relative fatness had significant seasonal variation characteristics, with highly significant effects of sex and body length (P<0.01). With increasing body length, the relative fatness showed two types of changes, continuously increasing and first increasing then decreasing, with salinity and b significantly affecting the type of change (P<0.05) and depth having a highly significant effect (P<0.01). The bigeye grunt off the coast Sierra Leone exhibited significant seasonal growth characteristics, with significant differences in growth characteristics between male and female individuals. This study suggested that salinity may be the main factor affecting its growth and development. In addition, this study hypothesised that the peak breeding season may occur during the dry season, beginning in December and ending before April of the following year. The study provides updated and more comprehensive insights into the biology and ecology of the bigeye grunt offshore Sierra Leone, West Africa, which can provide scientific basis for its resource assessment, development and utilization, and resource management.