Ajayi Crowther University

Typhoid fever, caused by Salmonella enterica serovar Typhi, remains a significant public health challenge in Nigeria, contributing to prolonged hospitalizations and straining healthcare systems. This retrospective study at Lagos State University Teaching Hospital (LASUTH) from 2019 to 2023 investigated the factors influencing the length of hospital stay among 215 typhoid fever patients. Using a chi-square test of independence, the study analyzed associations between hospitalization duration (categorized as Normal: 1–7 days, Mild: 8–14 days, Severe: ≥15 days) and patient characteristics, including age, gender, and type of typhoid infection (S. Typhi vs. P. Typhi). Results revealed a significant association between hospitalization duration and age (χ² = 16.350, p = 0.037), with younger patients (1–36 years) predominantly experiencing shorter stays and older patients (55+ years) showing prolonged hospitalizations. Similarly, the type of typhoid infection was significantly associated with hospital stay length (χ² = 7.097, p = 0.029), with S. Typhi infections linked to longer stays compared to P. Typhi. Gender showed no significant association with hospitalization duration (χ² = 0.389, p = 0.823). These findings underscore the influence of age and pathogen type on clinical outcomes, highlighting the need for tailored interventions, such as early screening for complications in older patients and optimized antibiotic strategies for S. Typhi infections, to reduce hospitalization duration and improve resource allocation in resource-constrained settings.

L-asparaginase is an enzyme used to treat acute lymphoblastic leukaemia due to its ability to break down external L-asparagine necessary for the growth of cancer cells. This work investigated the optimisation of L-asparaginase production and the effect of various factors on the activities of the produced enzyme. An L-asparaginase-producing bacterium collected from the Department of Microbiology and Biotechnology Laboratory was identified using 16S rRNA. The production of L-asparaginase was optimised using Response Surface Methodology (RSM), and the experimental design was validated. The effect of environmental factors on L-asparaginase was determined. The L-asparagine-producing bacterium was identified as Priestia megaterium GAFA with an accession number PP390497. Optimal production (10594.1 U/mL) was validated using glucose as a carbon source, L-asparaginase only as a nitrogen source, fermented at pH 7.76 for 73 hours with an inoculum load of 7.7%. The Ca²⁺ ion significantly increased L-asparaginase activity by 76% compared with the control at p<0.05. The enzyme was active over a wide pH range (4–8), with maximum activity at pH 6.0. The highest activity was observed at 60 °C after 1 hour of incubation. The production of L-asparaginase by Priestia megaterium GAFA was optimised, and environmental factors influenced its activity.

<title>Abstract</title> <bold>Background:</bold> <italic>Anopheles gambiae</italic> is a major malaria vector. There are documented evidences of insecticide resistance cases among mosquitoes in Nigeria and Sub-Saharan Africa. Insecticides recommended by WHO have proved to be less effective in the war against malaria and this problem seems intractable to the vector control programs. Herein we investigated prevalence of <italic>kdr</italic> gene <italic/> mutation <italic/> which is responsible for insecticide resistance in mosquitoes. <bold>Methods:</bold> A total of two hundred and fifty (250) <italic>Anopheles gambiae</italic> s.l mosquitoes were selected at random from the three different study locations in Kwara states, Nigeria. Morphological identification was carried out using standard keys. The insecticide susceptibility bioassay was conducted using WHO protocol. WHO impregnated insecticide papers of recommended discriminating concentrations of Permethrin (0.75%), Deltamethrin (0.05%) and Alphacypermethrin (0.05%) were used for the bioassay. Twenty-five (25) female non-blood fed <italic>Anopheles</italic> mosquitoes aged 2-5 days were introduced into WHO tubes containing a treated paper in four replicates and monitored for the number of mosquitoes that was knocked down at time intervals of; 10, 15, 20, 30, 40, 50, 60 minutes. On a subset of exposed <italic>Anopheles gambiae</italic> s.l, molecular identification of the sibling species and knock down resistance ( <italic>kdr</italic> ) gene mutation detection was carried using conventional PCR. <bold>Results:</bold> Morphological identification revealed that they were all <italic>Anopheles gambiae</italic> s.l. mosquitoes. Molecular identification revealed that seventy-eight (31.2%) of the samples were <italic>Anopheles coluzzii</italic> , forty-two (16.8%) as <italic>Anopheles gambiae</italic> s.s and thirty-four (13.6%) as <italic>Anopheles arabiensis</italic> . DNA samples of forty-six (18.4%) of the mosquito samples did not amplify at all. Analysis for kdr gene mutation showed that 104 and 146 samples were homozygous resistance and homozygous susceptible respectively. There were no observed cases of heterozygous resistance. Frequency of Kdr allele in <italic>Anopheles gambiae</italic> s.l. in Kwara State showed that homozygous resistant (RR), heterozygous resistant and homozygous susceptible (rr) 41.6%, 0.00% and 58.4% respectively. <bold/> The highest percentage mortality for the three insecticides was recorded in Oyun community with 61%, 58% and 64% recorded for permethrin, deltamethrin and alphacypermethrin respectively. The lowest mortality rates for all the insecticides were recorded in the post office community with 23%, 24% and 39% mortality recorded for permethrin, deltamethrin and alphacypermethrin respectively. Result of “knockdown time” in the three (3) LGAs revealed that Permethrin had the least knockdown impact across all the LGAs while Deltamethrin had the highest percentage knockdown with KDT ₅₀ of 52.80 (47.86-59.98), 32.75 (26.04-40.38) and 38.95 (31.62-48.96) for Ilorin West, Ilorin East and Ifelodun LGAs respectively. <bold>Conclusion</bold> . This study concludes that there are cases of kdr gene mutation among <italic>An. gambiae</italic> in the three study locations in Kwara state, <italic/> suggesting possibilities of high prevalence of malaria cases in the studied area. This study suggests that there should be a need to urgently and effectively monitor and address problems associated with the occurrence of insecticide-resistance in order to design effective and sustainable vector control.

The chi square test is an essential method in statistical research because it allows scholars to examine whether two categorical variables share a meaningful relationship by comparing observed and expected frequencies to evaluate evidence against the null hypothesis. This paper presents an overview of the chi square probability distribution and its core properties, including its mean, variance, moment generating function, and characteristic function. It also outlines the types of data that suit the chi square framework, the conditions required for valid use, and the limitations that researchers must consider along with alternative statistical options when assumptions are not satisfied. The discussion further explores the three major applications of the chi square procedure which are the goodness of fit test, the test of homogeneity, and the test of association or independence, each illustrated through examples drawn from research settings and educational contexts

<title>Abstract</title> Green roofs have gained prominence as sustainable solutions to urban challenges, addressing climate change, urban heat effects, and the need for enhanced energy efficiency. This review evaluates how green roofs contribute to urban sustainability by examining their dual roles in carbon sequestration and energy efficiency. The objectives are to synthesize empirical evidence on vegetation- and substrate-driven carbon dynamics, assess the extent to which green roofs reduce building energy demand, and identify the environmental and policy conditions that shape their performance. A PRISMA-based systematic literature review was used across five major databases to examine green roofs’ carbon sequestration and energy-efficiency benefits. From 3,000 records, 80 peer-reviewed studies met the inclusion criteria. Thematic analysis synthesized evidence on carbon dynamics and thermal performance, though language and database limitations remain. Findings reveal that green roofs deliver measurable environmental benefits. Vegetation species such as Sedum acre and Frankenia thymifolia directly sequester atmospheric carbon, while substrate microbial processes enhance long-term carbon storage. Indirect carbon reductions stemming from lower energy demand often exceed direct sequestration. Green roofs also lower cooling loads by up to 70%, reduce indoor temperatures significantly during peak heat periods, and contribute to urban heat island mitigation. Performance varies according to vegetation type, substrate depth, seasonal conditions, and maintenance practices. The study concludes that green roofs hold substantial potential for climate-responsive urban development. It recommends stronger policy frameworks, targeted financial incentives, standardized performance metrics, and expanded research on substrate science. Integrating green roofs into broader green infrastructure networks and ensuring equitable access, especially for vulnerable communities, will further enhance their sustainability impact.

One of the most notable climatic phenomena associated with urbanization is the Urban Heat Island (UHI) effect. This research aim to detect and analyze Urban Heat Island of Akinyele Local Government Area, Oyo State, using remote sensing and GIS technology to comprehensively understand, monitor, and mitigate the Urban Heat effect in the study area. This research explores the dynamics of urban heat islands (UHIs) by analyzing l and use changes, temperature variations, and population growth in Akinyele LGA, Oyo State using Landsat 7 &amp; 8 datasets and ArcGIS Software. Accuracy assessments were performed by comparing classified land cover maps with ground coordinates. Result shows that from 2004 to 2024, land use shifted significantly: Urban or built-up areas increased from 14.04% to 23.09%, forest areas increased from 29.78% to 37.82%, and light vegetation reduced from 56.18% to 39.09%. Concurrently, temperature data reveals a rising trend, the mean temperature increased from 29.574°C in 2004 to a 31.583°C in 2024. The population of Akinyele is projected to grow from 211,811 in 2006 to approximately 315,361 by 2024, driven by an annual growth rate of 2.39%. The future projections for urban land cover and land surface temperature (LST) indicate a significant rise in built-up areas and temperatures. The Built-up area is expected to reach 119.71 by 2034. Also, the LST is projected to rise to 36.031°C by 2034. This accelerated expansion of built-up areas intensifies the Urban Heat Island effect. These projections highlight the urgent need for effective urban planning strategy to mitigate the impacts of rapid urbanization and rising temperatures.

The study aimed at evaluating the extent to which non-performing loans and fraud affect the financial performance of Tier 1 deposit money banks in Nigeria. The study made use of secondary data which are gotten from central bank statistical bulletin 2025. The study made use of the multiple regression method for the analysis. The study therefore concluded that there is a significant relationship between fraud cases, non-performing loans and financial performance of tier 1 deposit money banks in Nigeria. The study recommends that Tier 1 banks should enhance their risk management frameworks to effectively address non-performing loans and fraud. This includes implementing stricter credit controls, conducting regular loan portfolio reviews, and investing in advanced fraud detection technologies.

The contamination of agricultural sites by heavy metals poses a serious threat to human health as these metals can enter the human body through food consumption. This study focuses on assessing heavy metal contamination and probable ecological risk in agricultural areas along the Asa River floodplains in Ilorin, Nigeria. Ten soil samples were collected and analyzed using Inductively Coupled Plasma-Mass Spectrophotometer (ICP-MS). Contamination risk index applied are degree of contamination, geo-accumulation index (Igeo), pollution load index (PLI) and potential ecological risk index (PERI). Pearson Correlation matrixes Analysis (PCA) were employed to identify contamination sources and relationships between heavy metals. Results showed varying concentrations of heavy metals with lead exceeding permissible limits in some locations. However, Zinc, Copper, Nickel, Chromium, Cobalt, and Arsenic were within acceptable thresholds, indicating anthropogenic influences. Most of the sampled areas are unpolluted except for KFG 5 polluted with lead. A Low to considerable degree of lead contamination, minimal to significant lead enrichment and low to considerable potential ecological risk of lead was observed. Correlation analysis revealed interdependencies among heavy metals, suggesting common contamination sources. Emphasizing the probable lead contamination in agricultural soil samples along the Asa River floodplains and the need for effective management strategies to protect human health and environment from pollution and eutrophication.

Despite growing global interest in improving mathematics outcomes, there has been limited empirical research in Nigeria that has rigorously evaluated the impact of structured after-school intervention programs on low-achieving students, particularly through a gender-based lens. This study addresses this gap by examining the effectiveness of after-school mathematics instruction on the performance of senior secondary school students in Oyo State, Nigeria. The researchers adopted a quasi-experimental pretest–posttest control group design with a 2 × 2 factorial structure. The sample consisted of 92 purposively selected low-achieving students (47 males and 45 females) from eight public, co-educational secondary schools, who were randomly assigned to experimental and control groups. Over the course of six weeks, the experimental group received structured after-school mathematics lessons that targeted foundational skills, while the control group continued with conventional classroom instruction. Data was collected using a researcher-developed Mathematics Achievement Test (MAT), which was validated by mathematics education experts and yielded a Cronbach’s alpha of 0.82. Analysis of Covariance (ANCOVA) revealed a statistically significant improvement in the mathematics achievement of students in the intervention group (F(1, 87) = 114.88, p &lt; 0.05), with a large effect size (Partial η2 = 0.569). Although no significant interaction effect between gender and treatment was observed (F(1, 87) = 0.208, p &gt; 0.05). This study contributes to the limited literature on gender-responsive after-school interventions in sub-Saharan African contexts. Findings support the implementation of targeted support programs to enhance mathematics outcomes for struggling learners, regardless of gender.