Petrological and structural evolution of basement rocks around Guga, Katsina State, northwestern Nigeria

Lithological characterization and structural assessments of basement rocks around Guga, Katsina State was carried out to understand their geologic evolution and deformational history better. Field and petrographic studies were utilized in characterizing macrostructural, textural, and mineralogical components. Migmatite, banded and augen gneisses, schist, quartzite, and granite constitute the major lithologic units in the study area. Migmatite and the closely related banded gneiss are recognized as igneous-derived metamorphic rocks of Eburnean to early Pan African. In contrast, the augen gneisses are metamorphosed analogues of earlier banded gneiss that were intensely deformed within a ductile shear zone during the middle stages of the Pan African. Similarly, the schist and interbedded quartzite were emplaced during this period, subsequently forming part of the Malumfashi supracrustal cover, related to simple ensialic graben-like structural development. The granitic intrusions represent the youngest rock units in the mapped area, resulting from the magmatic activity of the Pan-African orogeny. Structural analysis suggests the mapped area was affected by two-phase deformation events (D1 and D2). The D1 deformation represents a regional, fabric-forming compressional event, while D2 is a localized deformational event associated with the development of a local shear zone linked to the Kalangai fault system (KFS)

A new spectrophotometric method for the determination of methyldopa

AbstractA new, simple and low cost spectrophotometric method for the determination of methyldopa in pharmaceutical preparations was developed. The method was based on the coupling of methyldopa with 2,6-dichloroquinone-4-chlorimide (DCQ). The absorbance maximum (λmax) of the resulted colored product was at 400nm. Different buffers were used to determine the optimal pH for the reaction. About 1% w/v acetate buffer with pH 8.0 gave the optimal pH required for the reaction. Of the different solvents tried, water and ethanol were found to be the most suitable solvents. Beer’s law was obeyed in concentration range of 4–20μg/ml methyldopa. The correlation coefficient was found to be (r=0.9975). The limit of detection and limit of quantification were 1.1μg/ml and 3.21μg/ml, respectively. The reaction ratio between methyldopa and DCQ was studied and found to be 1:3. The work included the study of the possible interference of hydrochlorothiazide found in combination with methyldopa tablets. The method was validated and results obtained for the assay of two different brands of methyldopa tablets were compared with the BP method (colorimetric). The repeatability and reproducibility of the developed method were evaluated and the obtained results quoted. The derivative formed as a result of the reaction of methyldopa with DCQ was isolated and its possible mechanistic pathway was suggested

Solar selective performance of metal nitride/oxynitride based magnetron sputtered thin film coatings: A comprehensive review

Since solar thermal collectors are considered to be the most direct way of converting the solar energy into the usable form, in the last few years growing attention has been paid to the development of transition metal nitride and metal oxynitride based thin film selective surfaces for solar-thermal collectors in order to harvest more solar energy. A solar-thermal energy system, generally, shows very high solar absorption of incident solar radiation from the solar-thermal collectors in the visible range (0.3 to 2.5 μm) and extremely low thermal losses through emission (or high reflection) in the infrared region (≥ 2.5 μm). The efficiency of a solar–thermal energy conversion system can be improved by the use of solar selective surfaces consisting of novel metallic nanoparticles surrounded in metal nitride/oxynitrides systems. In order to enhance the effectiveness of solar thermal devices, solar selective surfaces with high thermal stability are a prerequisite. Over the years, substantial efforts have been made in the field of solar selective surfaces to attain higher solar absorptance and lower thermal emittance at high temperature (above 400°C) applications. In this article, we review the present state-of-the-art transition metal nitride and/or oxynitrides based vacuum sputtered nanostructured thin film coatings with respect to their optical and solar selective surface applications. We have also summarized the solar selectivity data from recent published literature investigations, including discussion on some potential applications for these materials

Determination of origin and granulometric analysis of river channel sediments of Osi, southwestern Nigeria

Osi is located within the south-western part of the Nigerian Basement Complex and plays a host to unconsolidated deposits and major examples of Precambrian – Paleozoic crystalline rocks in the region. Detailed geological mapping revealed the area to comprise essentially of migmatite – banded gneiss complex and diorites and minor rock types that include pegmatite and quartz veins. Superficial stream sediments occur abundantly and proximally along channels in the vicinity. These river channels host considerable amount of loose deposits that are useful for sedimentological and provenance study. While efforts have been committed to regional mapping, petrography and geochemistry of rocks in the region, little attention was paid to the associated stream sediments. This study adopted geological mapping of the crystalline rocks and sieve analysis of the stream sediments, as well as the use of XRF and inductively coupled plasma Mass spectrometry (ICP – MS) to establish some relationship between the basement geology and the surrounding deposits in the area. Migmatites are abundant in the south-west and parts of the north-west, while granite gneisses with isolated occurrence of diorite are confined to the north-east of the study area. Granulometry of the sediments revealed a predominantly medium – coarse grained, poorlysorted leptokurtic sands, indicating products of in-situ weathering of host rocks. Geochemical analysis supports a strong correlation between the rocks and the sediments. The study is applicable to enhanced understanding of grai -size distribution and in regional mapping and geochemical method of exploration.Keywords: Basement complex, migmatite – gneiss complex, stream sediments, grai -size analysis, elemental abundance, south-western Nigeri

Comparative study of proximate composition of some wild tilapiine fishes in Epe Lagoon, Lagos, Nigeria

The proximate composition of some wild tilapiine fishes in Epe lagoon, Lagos, Nigeria was analyzed. The species were Sarotherodon melanotheron, Tilapia guineensis, Tilapia mariaei, Sarotherodon galileaus and an ecotype cichlid popularly called ‘wesafu’. Major nutrient compositions of raw muscles like protein, fat, moisture and ash were determined. Proximate compositions were found to be varied among the species. Protein was determined in Sarotherodon melanotheron (19.13%), T. guineensis (18.71%), T. mariae (18.08%), S. galileaus (18.34%) and ‘wesafu’ (21.80%) respectively. Lipid content was recorded as 0.82%, 0.40%, 0.60%, 0.65%, and 0.90% for the tilapia species. The highest level of moisture content was found in T. guineensis (81.70%) and the lowest was in ‘wesafu’ (78.50%). The percentage of ash content was highest in S. galileaus and S.melanotheron (1.75%) and lowest in T. guineensis (1.00%). The present study revealed highest protein content in the ecotype cichlid, wesafu (19.22%) and lowest value in T.mariae (18.08%) while fat was highest in ‘wesafu’ (0.90%). The results of this study reveal the nutritional significance of the ecotype cichlid, ‘wesafu’ above other cichlids of the lagoon

Role of sequential semen samples in infertile men candidates for assisted reproduction: A prospective study

Objective: To study the beneficial effect of repeated sequential ejaculation in infertile men who are candidates for assisted reproduction.Materials and methods: The study included a total of 237 infertile males attending our infertility and IVF center from January 2016 till December 2017. All patients were asked to provide two semen samples (1–3 h apart) after an abstinence period of 3–7 days. The two consecutive semen samples were analyzed according to the 2010 WHO criteria for semen analysis and their parameters were compared.Results: The mean age for our study group was 35.7 years (20–56 year). Of the 237 subjects, 157 showed oligoasthenozoospermia on their initial semen sample while the remaining 80 were azoospermic. A statistically significant difference was detected between the 2 sequential semen samples regarding all semen parameters except grade A motility. Despite the significant decrease in seminal volume by sequential sampling, there was a statistically significant increase in sperm concentration in the second ejaculate compared to the first (6.2 ± 0.61 versus 3.4 ± 0.52 million/mL, respectively, p = 0.016). The mean normal sperm morphology also demonstrated a significant increase (2.1 ± 1.8–5.1 ± 2.6%, p < 0.002). Mean progressive sperm motility increased from 1.13 ± 0.31 to 1.7 ± 0.31% (p = 0.010) on repeated sampling. Also, we were able to retrieve viable sperm in 15% of the azoospermic patients whom were known to be azoospermic on previous occasions.Conclusions: Obtaining consecutive semen samples leads to improvements in the quality of many semen parameters (sperm concentration, motility and morphology) which may be of special importance for management of infertile couples especially those attempting assisted reproductive techniques

Sustainable Energy Future for Nigeria: The Role of Engineers

Energy is an essential input for social development and economic growth. It provides basic needs and services such as heating, cooling, cooking, lighting, and transportation and is a critical production factor in virtually all sectors of industry. Sustainable energy development has currently taken over the lead as the most focal point in determining the developmental level of countries in the world. This paper discussed the current status of energy, examined the development and energy infrastructure in Nigeria. Engineers have a unique role to play in order to achieve this objective when compared with other occupations in industrial organizations. They play a semi-independent role influenced by their national diversity. Engineers, therefore, are under increasing pressure to redefine their roles and re-equip themselves with necessary skills and knowledge to meet adequately the contemporary changes. The paper also looked at the challenges engineers face in carrying out this role and also made suggestion of the possible ways of addressing those challenges

Open-array analysis of genetic variants in Egyptian patients with type 2 diabetes and obesity

Background: Diabetes mellitus is considered a major public health problem worldwide. Susceptibility to diabetes is influenced by both genetic and environmental determinants.Aims/hypothesis: The aim of the present study was to test for 16 independent single nucleotide polymorphisms (SNPs) in established Type 2 diabetes (T2D) and obesity susceptibility loci by GWAS in a sample of Egyptian patients to find out if there is shared genetic background underlying both disease entities.Methods: Genotyping was performed using OpenArray protocol on the QuantStudioTM 12K Flex Real- Time PCR System. In the present case control study a custom array was designed to facilitate costeffective analysis of selected SNPs related to glycolysis, gluconeogenesis, inflammation, insulin signalling, and immune function.Results: Seven gene variants showed significant association with the risk of T2D patients including FCGRA2, STAT4, CELSR2, PPARG, EXT2 rs3740878, GCKR, PTGS1. Factors that significantly affect T2D were obesity (p < 0.001) and GCKR (p = 0.001) and PTGS1 (p = 0.001) gene variants. Gene variants that showed significant or borderline effect on obesity were MTHFD1, EXT2 rs3740878, GCKR and PTGS1 (p = 0.03, 0.017, 0.059, 0.006) respectively.Conclusions/interpretation: Overlapping genetic aspects should be considered and the presence of risk alleles of different genes together could contribute to the risk of T2D or obesity or both. The MTHFD1 and EXT2rs3740878 gene variants significantly affect obesity and not shared with T2D. Gene variants that showed combined effect on both disease entities were GCKR and PTGS1. These findings provide a basis for future studies on a larger scale. More stress on the risk gene variants that have a combined impact on both diabetes and obesity is recommended to improve risk prediction and preventive strategies

Diagnostic value of bronchoalveolar lavage in the subset of patients with negative sputum/smear and mycobacterial culture and a suspicion of pulmonary tuberculosis

Background: The diagnostic value of bronchoalveolar lavage in patients with negative sputum/smear for tuberculous bacilli has been well studied. However, its value in the subset of patients with both negative sputum/smear and culture is seldom reported. Methods: A retrospective study of patients referred for diagnostic bronchoscopy for the suspicion of pulmonary tuberculosis during the period from April 1st, 2015 to March 30th, 2016, and who had negative sputum/smear and culture for tuberculous bacilli. Results: One hundred and ninety patients fulfilled the inclusion criteria. Bronchoalveolar lavage detected further 61/190 (32.1%) pulmonary tuberculosis cases. Bronchoalveolar lavage mycobacterial culture and polymerase chain reaction (positive in 60/190 (31.6%) and 58/190 (30.5%) of patients respectively) provided the highest diagnostic yield, whereas direct smear provided the lowest yield. Bronchoalveolar lavage had a sensitivity of 89.7%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 94.6%, and a test accuracy of 96.3% in suspected pulmonary tuberculosis cases with negative sputum/smear and culture. Positive bronchoalveolar lavage yield for tuberculosis was significantly associated with a positive QuantiFERON-TB Gold In-Tube test, positive purified protein derivative skin test, radiological evidence of upper zone abnormality and patient's origin being from the Indian subcontinent. Conclusion: Bronchoalveolar lavage should be pursued as a useful diagnostic tool for suspected pulmonary tuberculosis cases when sputum/smear and culture are negative. Its value is higher in the subset of patients with positive QuantiFERON-TB Gold In-Tube test, positive purified protein derivative skin test, upper zone abnormality on radiograph or being from the Indian subcontinent.Scopu