SOUTHERN JOURNAL OF SCIENCES

Background: The lack of comprehensive baseline data on raw sewage pollution in Minna, Nigeria's Niger State capital, represents a significant gap in public health information. This deficiency necessitates a systematic study to establish a database documenting sewage pollution patterns in Minna's urban environment. Aim: To employ georeferencing tools and descriptive observations for identifying and mapping potential mosquito breeding sites related to sewage discharge within Minna's built-up areas and to develop an interactive Geographic Information System (GIS) map as an environmental audit tool for public health officials. Methods: The study area was divided into five sectors: Greater Bosso, Minna Central, Greater Maitumbi, Tunga, and Greater Chanchaga. Following initial site familiarization and GIS equipment testing, systematic surveys were conducted. Field teams documented locations of household sewage discharge points, collecting geographic coordinates, temporal data (date, time, weather conditions), and site characteristics. Each identified location was photographed and recorded in standardized data sheets, including household information where available. Results: Using ArcGIS®10.8 software, comprehensive sewage pollution layers were created for each sector by integrating collected field data with Minna's township built-up and settlement shapefiles. The mapping revealed distinct pollution patterns and clusters across different neighborhoods. Discussion: Analysis of the spatial distribution showed a clear correlation between socioeconomic status and sewage management practices, with higher concentrations of improper sewage discharge in low-income areas. Conclusions: This database serves as a valuable resource for public health interventions targeting mosquito breeding grounds. Regular monitoring through periodic sewage pollution audits and expanded geographical coverage is recommended for improved urban health management.

Background: MQ-series gas sensors belong to the metal oxide semiconductor (MOS) family of sensors that can sense the presence of many gases. These sensors find their application in gas alarm systems as key components. While necessary sensor circuit output voltage value for alarm point in a stand-alone gas alarm system is desirable, but what exact combination of the sensor circuit parameters is required? Hitherto, the determination of these circuit parameters has not been given much attention in the research community. Aim: the purpose of this work is to explore a structured graphical approach of determination of MQ series gas sensor circuit parameters for a stand-alone gas alarm system that yields desired sensor circuit output voltage value for the alarm point; the main objective of the study was to develop mathematical model equations that relate the: (i) sensor resistance (RS) with the gas concentration (x) and the sensor resistance at standard calibration concentration of the sensor base gas in the clean air (Ro) and (ii) sensor circuit output voltage (VRL), load resistance (RL) and sensor resistance (RS). It is expected from the model equations developed that graphical correlations of the sensor circuits parameters will be generated. Using these graphs for a particular case of an MQ-4 gas sensor under the influence of LPG, the parameters that yield desired sensor circuit output voltage of 2V for 1000 ppm of LPG alarm point will be determined. Methods: Model equations were developed for the sensor dynamics, and based on these model equations, graphs for the determination of required sensor parameters were plotted for a case of MQ-4 gas sensor response to LPG. Results and Discussion: The results yielded optimal values for R_O,R_S and R_L of 20 kΩ, 30 kΩ and 20 kΩ respectively, for alarm settings of 1000 ppm and a desired sensor circuit output voltage of 2 V. Based on determined parameters, the calibration equation for determination of best concentration value for a given value of emulated LPG concentration was developed. Using the method proposed in this study makes the process of determining the MQ-series gas sensor circuit parameters less cumbersome as their value can easily be obtained from the resulting graphs. Conclusions: a structured graphical approach for determination of MQ-series gas sensor circuit parameters for alarm points in a stand-alone gas alarm system showed that using MQ-4 gas sensor and LPG as the target gas, and for a sensor circuit output voltage of 2 V for alarm point at 1000 ppm of LPG, the corresponding value of R_O, R_S and R_L obtained were 20 kΩ, 30 kΩ, and 20 kΩ respectively. Hence, a structured graphical approach is suitable for determining MQ series gas sensor circuit parameters for a stand-alone gas alarm system under the influence of its associated gases.

Background: Diabetes Type 2 is a complex disorder described by an imbalance between insulin resistance and secretion that induce liver glucose output. It has been shown that serum insulin levels are affected by a sperm plasma membrane and acrosome. Therefore, during insulin resistance spermatogenesis changes, diabetic patients detect testicular changes. Aims: This research aims to know the effect of diabetic type 2 on some aspects of fertility in men by studying the characteristics of the semen and some biochemical parameters in seminal plasma. Methods: This study was achieved at the Center for Endocrinology and Diabetes Specialists in Maysan province from February to November 2018 and included 45 men (30 diabetic and 15 healthy in the control group) aged 30 to 59 years. The patients were divided according to age into two groups, the first (30-39) and second (40-59) years, also divided by the duration of diabetes into two groups, the first (1-5) and second (6-10) year. Results: The pH of semen in the second age group (40-49 years) group and first duration (1-5 years) group were significantly decreased (P <0.05) in diabetes compared with the control group. Volume and viscosity did not have significant differences in patients compared to the control following the age and duration of diabetes. Liquefaction only in the first age (30-39 years) group significantly increased (P <0.05) compared to the control. The concentration of sperm, progressive motility, non-progressive and normal morphology decreased (P <0.05) significantly. While the sluggish, dead, and abnormal morphology significantly increased (P <0.05) in all diabetes groups compared with the control. The fructose and alkaline phosphatase values in the seminal plasma were not differing significantly in patients compared with the control. Zinc and glutathione values decreased significantly (P <0.05) compared with control in each age and duration of diabetes. Discussion: Insulin stimulates the Ledying cell function, defect insulin effect on spermatogenesis. Impaired sperm motility in a patient with D.M. might be attributed to many reasons, such as increased ROS level, altered mitochondria DNA, and decreased epididymal products. Conclusion: our measurement indicates that there is an effect of type 2 diabetes mellitus on semen parameters and seminal plasma biochemical parameters.