Redox Kinetics and Mechanism of the Reactions of µ –Oxobis [aquobis (2,2’ – Bipyridine)] diruthenium (III) Ion and some Aliphatic Alcohols in Acidic Medium

The redox kinetics and mechanisms of the reactions of μ – oxobis[aquobis(2,2’ - bipyridine)]diruthenium (III) ion, [(bipy)2(H2O)RuORu(H2O)(bipy)2]4+ (hereafter denoted as Ru2O4+ or [(H2O)2(bipy)4Ru2O]4+) and some primary aliphatic alcohols was studied in perchloric acid medium, [H+] = 5.0 x 10-3 mol dm-3, ionic strength (I), = 0.5 mol dm–3 (NaClO4), temperature (T) = 31 ± 1°C and  wavelength ,λmax =  660 nm. The reactions, which led to the formation of corresponding aldehydes had a stoichiometry of 1:1, were all first order with respect to each reactant, and second order overall. The reactions proceeded in the absence of acid but when acid was added, the reactions ceased. Varying the ionic strength and dielectric constants of the reaction medium had no effect on the reaction. Added ions catalysed the reaction and free radicals were identified in the reaction mixtures in the course of the reactions. There was no evidence for the formation if intermediate complex in the course of the reaction. The order of reactivity is of the order CH3OH > C2H5OH > C3H7OH Based on the  results, it is suggested that all the reactions proceeded through the outer – sphere electron transfer mechanism and a plausible mechanism that represented all the reactions is proposed

Human-Induced Impacts on Land Surface Temperature Dynamics in Osogbo, Osun State, Nigeria

The main goal of this study is to evaluate the impacts of humaninduced activities on land surface temperature dynamics of Osogbo, in Osun State, Nigeria. Land surface temperature dynamics, land use land cover dynamics and the relationship between land surface temperature (LST) and land-use land-cover (LULC) were assessed using Landsat satellite data (ETM+ and OLI/TIRS) of Oshogbo, Osun State, Nigeria. The radiometrically corrected thermal infrared bands of the Landsat images of 2000 and 2018 were used to retrieve land surface temperature while the Maximum Likelihood algorithm in Erdas imagine 9.2 was used to generate a classified image for the two periods. Land surface temperature maps, land cover index maps and Normalized Differential Vegetation Index (NDVI)) were generated. Correlation analysis using Pearson’s Product Moment Method was carried out between land surface temperature and normalized differential vegetation index (NDVI) data and the land cover index was digitized and overlaid on the LST map of 2018 to determine the association between them. The results revealed noticeable decrease in vegetated areas of Osogbo with an accompanying increase in land surface temperature from 28.045°C in 2000 to 29.200°C in 2018. Built-up increased within the same periods from 19 to 42%, which could be attributed to anthropogenic activities. The land surface temperature distribution maps showed a more pronounced intensity in areas of significant human activities than in areas covered by vegetation and waterbody. The correlation coefficient values of –0.54418 and -0.48513 observed in the land surface temperature and normalized differential vegetation index values for 2000 and 2018 respectively, indicated an inverse relationship between the two variables. The study concluded that the nature of land use / land cover patterns in Osogbo have impacted its land surface with a corresponding increase in land surface temperature. It is expected that as the city expands further, the magnitude of the land surface temperature will also increase thereby affecting the living conditions of the urban populace

Celebrity Expertise and Congruence on Consumer Purchase Intentions: Evidence by Nigerian Mobile Telecommunication Companies

Purpose: Celebrity endorsement is a marketing strategy firms have embraced to survive and fortify their market competitiveness. This study examined how celebrity expertise and congruence affect consumer purchase intentions in Nigerian telecommunications companies.   Theoretical framework: The theory of planned behaviour describes all behaviour of individuals who possess the power to exercise self-restraint. The predictors of purchase intentions as submitted by this theory comprised attitudes; behavioural intention; subjective norms; and perceived behavioural control.   Method: It adopted a survey research design. A proportionate stratified random sampling technique was employed in the research while a questionnaire was used to gather participant data. The instrument was validated while the reliability tests ranged between 0.654 and 0.795. A Partial Least Square (PLS) modelling was adopted to analyse data collected from the respondents.   Findings: The findings showed that celebrity expertise and celebrity congruence all have a significant positive effect on consumers’ intention to purchase in the Nigerian mobile telecommunication operators in Lagos State, Nigeria.   Research Implication: The managerial implication is that it will enhance inter-enterprise collaborations among telecommunications companies by working together with their ideas and skills to accomplish a desired task that is innovative in nature for the benefit of the companies.   Originality/Value: This study is the first of its kind to deal with celebrity expertise and celebrity congruence on consumers’ intention to purchase in the Nigerian mobile telecommunication operators in Lagos State, Nigeria

Synthesis, Characterization, and Biological Evaluation of Chromium(III) Complexes of Alanine and Valine

Two metal-amino acid complexes, Cr(III)-alanine and Cr(III)-valine, were synthesized and characterized by IR spectroscopy, powder X-ray diffraction (XRD) analysis, magnetic susceptibility, and molar conductivity measurements. Molar conductivity measurements indicated that the composition of the metal complexes corresponds to a metal-amino acid ligand ratio of 1:3. The IR spectra indicated that the amino acids act as bidentate ligands with coordination involving the carboxyl oxygen and the nitrogen of the amino group. Magnetic susceptibility measurements revealed a six-coordinate local symmetry around the Cr(III) ions which depicted that the complexes were paramagnetic with magnetic moment values ranging from 5.10 to 6.00 BM. Powder XRD studies confirmed that the amino acid complexes were crystalline with monoclinic crystal structure. The in vitro biological activity of the investigated chromium(III) complexes with alanine and valine was tested against Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli. All the microorganisms were standardized using 0.5 McFarland standard. The antimicrobial studies showed that the ligands were biologically active with an inhibition zone range of 10-17 mm and their metal complexes showed significantly enhanced antimicrobial sensitivity with an inhibition zone range of 12-21 mm. The standard drug showed slightly better activity with an inhibition zone range of 24-38 mm

IL-15 Participates in the Respiratory Innate Immune Response to Influenza Virus Infection

Following influenza infection, natural killer (NK) cells function as interim effectors by suppressing viral replication until CD8 T cells are activated, proliferate, and are mobilized within the respiratory tract. Thus, NK cells are an important first line of defense against influenza virus. Here, in a murine model of influenza, we show that virally-induced IL-15 facilitates the trafficking of NK cells into the lung airways. Blocking IL-15 delays NK cell entry to the site of infection and results in a disregulated control of early viral replication. By the same principle, viral control by NK cells can be therapeutically enhanced via intranasal administration of exogenous IL-15 in the early days post influenza infection. In addition to controlling early viral replication, this IL-15-induced mobilization of NK cells to the lung airways has important downstream consequences on adaptive responses. Primarily, depletion of responding NK1.1+ NK cells is associated with reduced immigration of influenza-specific CD8 T cells to the site of infection. Together this work suggests that local deposits of IL-15 in the lung airways regulate the coordinated innate and adaptive immune responses to influenza infection and may represent an important point of immune intervention

The Redox Reaction between Di-μ-Oxo-Tetrakis (2, 2’- bipyridine) – Dimanganese (III, IV) Perchlorate and 1, 3-Dihydroxybenzene in Hydrochloric Acid

Communication in Physical Sciences 2020, 6(1): 738-745 Authors: Patricia Ese Umoru*and Ameh David Onu Received 10 October 020/Accepted 24 October 2020 The redox reaction between di-μ-oxo-tetrakis (2, 2’- bipyridine) – dimanganese (III, IV) perchlorate 3+ and 1,3-dihydroxybenzene ( Q) in hydrochloric acid was investigated using spectroscopic technique. The stoichiometry of the reaction was 2:3 for 3+: Q. The rate of reaction was first order with respect to both species while the overall rate of reaction was second order. Investigation of the effect of ionic strength on the reaction gave evident for non-dependence of the rate of reaction on change in dielectric constant, D, of the medium. The rate of the reaction increased with increase in the concentration of the acid and was found to be unaffected by the addition of added (Ni2+, NO3- and HCOO-) ions. There was no gel-formation in the course of the reaction and Michaelis-Menten’s type plot gave a straight line starting from the origin

CryCeleb: A Speaker Verification Dataset Based on Infant Cry Sounds

This paper describes the Ubenwa CryCeleb dataset - a labeled collection of infant cries, and the accompanying CryCeleb 2023 task - a public speaker verification challenge based on infant cry sounds. We release for academic usage more than 6 hours of manually segmented cry sounds from 786 newborns to encourage research in infant cry analysis

Effect of Intra-Row Spacing on the Damage Caused By Bollworm On Cotton In Zaria, Nigeria

Field trials were conducted at two locations in Samaru (110 11' N, 070 38' E and 686m above sea level) and Maigana (110 10' N, 070 37' E and 675m above sea level) both in Northern Guinea Savannah ecological zone of Nigeria during the 2018 wet season to determine the effects of three intra row spacing (40cm, 45cm and 50cm) on damage to cotton (SAMCOT 9) by bollworms. The experimental design was randomized complete block design. Data were recorded on the number of damaged shed squares, number of damaged shed cotton bolls and number of matured green bolls damaged by bollworms at two weeks interval beginning from 9WAS at the different phenological stages until about 90% of bolls were open, which was a period of about 16WAS before the commencement of the first picking. Significant reduction in the number of shed cotton squares, shed cotton bolls and matured green bolls damaged by bollworms were observed on the 50cm and 45cm intra row spacings than the 40cm intra row spacing

Plasmid-Encoded Interleukin-15 Receptor α Enhances Specific Immune Responses Induced by a DNA Vaccine In Vivo

Plasmid-encoded DNA vaccines appear to be a safe and effective method for delivering antigen; however, the immunogenicity of such vaccines is often suboptimal. Cytokine adjuvants including interleukin (IL)-12, RANTES, granulocyte-macrophage colony-stimulating factor, IL-15, and others have been used to augment the immune response against DNA vaccines. In particular, IL-15 binds to a unique high-affinity receptor, IL-15Rα; is trans-presented to CD8+ T cells expressing the common βγ chain; and has been shown to play a role in the generation, maintenance, and proliferation of antigen-specific CD8+ T cells. In this study, we took the unique approach of using both a cytokine and its receptor as an adjuvant in an HIV-1 vaccine strategy. To study IL-15Rα expression, a unique monoclonal antibody (KK1.23) was generated to confirm receptor expression in vitro. Coimmunization of IL-15 and IL-15Rα plasmids with HIV-1 antigenic plasmids in mice enhanced the antigen-specific immune response 2-fold over IL-15 immunoadjuvant alone. Furthermore, plasmid-encoded IL-15Rα augments immune responses in the absence of IL-15, suggesting its role as a novel adjuvant. Moreover, pIL-15Rα enhanced the cellular, but not the humoral, immune response as measured by antigen-specific IgG antibody. This is the first report describing that IL-15Rα itself can act as an adjuvant by enhancing an antigen-specific T cell response. Uniquely, pIL-15 and pIL-15Rα adjuvants combined, but not the receptor α chain alone, may be useful as a strategy for generating and maintaining memory CD8+ T cells in a DNA vaccine