Mechanical and Chemical Properties of Reinforcement Bars Manufactured in Nigeria

Reinforcement bars, or REBAR for short, are mainly produced from metal scrap or iron ore, or a combination of both. Their manufacturing process has a significant effect on their properties, so also are the percentage concentration of various constituent elements and the cooling rate in the production process. This research work aims to study the physical and chemical properties of rebars manufactured in Nigeria vis-à-vis their suitability for construction purposes. The effect of chemical composition in rebar on steel stresses was studied. Rebar samples were collected at various points in Abuja and its environs and tested for their mechanical and chemical properties. The results show some tolerable and intolerable deviations from provisions of BS 4449 B500B 2005 indicating that some of the rebars are satisfactory for use in reinforced concrete works while others are not. Tests conducted on the rebars include Tensile Strength, Relative Rib Area, Percentage Elongation, Bend and Rebend, and Spectrometer tests, among other physical examinations. In some rebars, results showed moderate to vast deviation from minimum acceptable standard values as specified in BS 4449 B500B 2005 for yield stress, elongation, bar diameter, mass per kilogram, carbon equivalent, while there is satisfactoriness for other tested samples

Strain-level resolution and pneumococcal carriage dynamics by single-molecule real-time (SMRT) sequencing of the plyNCR marker: a longitudinal study in Swiss infants

BACKGROUND Pneumococcal carriage has often been studied from a serotype perspective; however, little is known about the strain-specific carriage and inter-strain interactions. Here, we examined the strain-level carriage and co-colonization dynamics of Streptococcus pneumoniae in a Swiss birth cohort by PacBio single-molecule real-time (SMRT) sequencing of the plyNCR marker. METHODS A total of 872 nasal swab (NS) samples were included from 47 healthy infants during the first year of life. Pneumococcal carriage was determined based on the quantitative real-time polymerase chain reaction (qPCR) targeting the lytA gene. The plyNCR marker was amplified from 214 samples having lytA-based carriage for pneumococcal strain resolution. Amplicons were sequenced using SMRT technology, and sequences were analyzed with the DADA2 pipeline. In addition, pneumococcal serotypes were determined using conventional, multiplex PCR (cPCR). RESULTS PCR-based plyNCR amplification demonstrated a 94.2% sensitivity and 100% specificity for Streptococcus pneumoniae if compared to lytA qPCR. The overall carriage prevalence was 63.8%, and pneumococcal co-colonization (≥ 2 plyNCR amplicon sequence variants (ASVs)) was detected in 38/213 (17.8%) sequenced samples with the relative proportion of the least abundant strain(s) ranging from 1.1 to 48.8% (median, 17.2%; IQR, 5.8-33.4%). The median age to first acquisition was 147 days, and having ≥ 2 siblings increased the risk of acquisition. CONCLUSION The plyNCR amplicon sequencing is species-specific and enables pneumococcal strain resolution. We therefore recommend its application for longitudinal strain-level carriage studies of Streptococcus pneumoniae. Video Abstract

Strain-level resolution and pneumococcal carriage dynamics by single-molecule real-time (SMRT) sequencing of the plyNCR marker: a longitudinal study in Swiss infants.

BACKGROUND Pneumococcal carriage has often been studied from a serotype perspective; however, little is known about the strain-specific carriage and inter-strain interactions. Here, we examined the strain-level carriage and co-colonization dynamics of Streptococcus pneumoniae in a Swiss birth cohort by PacBio single-molecule real-time (SMRT) sequencing of the plyNCR marker. METHODS A total of 872 nasal swab (NS) samples were included from 47 healthy infants during the first year of life. Pneumococcal carriage was determined based on the quantitative real-time polymerase chain reaction (qPCR) targeting the lytA gene. The plyNCR marker was amplified from 214 samples having lytA-based carriage for pneumococcal strain resolution. Amplicons were sequenced using SMRT technology, and sequences were analyzed with the DADA2 pipeline. In addition, pneumococcal serotypes were determined using conventional, multiplex PCR (cPCR). RESULTS PCR-based plyNCR amplification demonstrated a 94.2% sensitivity and 100% specificity for Streptococcus pneumoniae if compared to lytA qPCR. The overall carriage prevalence was 63.8%, and pneumococcal co-colonization (≥ 2 plyNCR amplicon sequence variants (ASVs)) was detected in 38/213 (17.8%) sequenced samples with the relative proportion of the least abundant strain(s) ranging from 1.1 to 48.8% (median, 17.2%; IQR, 5.8-33.4%). The median age to first acquisition was 147 days, and having ≥ 2 siblings increased the risk of acquisition. CONCLUSION The plyNCR amplicon sequencing is species-specific and enables pneumococcal strain resolution. We therefore recommend its application for longitudinal strain-level carriage studies of Streptococcus pneumoniae. Video Abstract

Mechanical and Chemical Properties of Reinforcement Bars Manufactured in Nigeria

Reinforcement bars, or REBAR for short, are mainly produced from metal scrap or iron ore, or a combination of both. Their manufacturing process has a significant effect on their properties, so also are the percentage concentration of various constituent elements and the cooling rate in the production process. This research work aims to study the physical and chemical properties of rebars manufactured in Nigeria vis-à-vis their suitability for construction purposes. The effect of chemical composition in rebar on steel stresses was studied. Rebar samples were collected at various points in Abuja and its environs and tested for their mechanical and chemical properties. The results show some tolerable and intolerable deviations from provisions of BS 4449 B500B 2005 indicating that some of the rebars are satisfactory for use in reinforced concrete works while others are not. Tests conducted on the rebars include Tensile Strength, Relative Rib Area, Percentage Elongation, Bend and Rebend, and Spectrometer tests, among other physical examinations. In some rebars, results showed moderate to vast deviation from minimum acceptable standard values as specified in BS 4449 B500B 2005 for yield stress, elongation, bar diameter, mass per kilogram, carbon equivalent, while there is satisfactoriness for other tested samples

Removing the barrier to the calculation of activation energies: Diffusion coefficients and reorientation times in liquid water

See also: The Journal of Chemical Physics 145 (13), 134107 (2016). The following article appeared in Piskulich, Z. A., Mesele, O. O., & Thompson, W. H. (2017). Removing the barrier to the calculation of activation energies: Diffusion coefficients and reorientation times in liquid water. The Journal of Chemical Physics, 147(13), 134103. and may be found at https://aip.scitation.org/doi/10.1063/1.4997723.General approaches for directly calculating the temperature dependence of dynamical quantities from simulations at a single temperature are presented. The method is demonstrated for self-diffusion and OH reorientation in liquid water. For quantities which possess an activation energy, e.g., the diffusion coefficient and the reorientation time, the results from the direct calculation are in excellent agreement with those obtained from an Arrhenius plot. However, additional information is obtained, including the decomposition of the contributions to the activation energy. These results are discussed along with prospects for additional applications of the direct approach

Agricultural Exports and Economic Growth in Nigeria (1980 – 2010)

This paper seeks to determine if a significant long-run relationship exists between agricultural exports and economic growth in the present-day Nigeria. It would also access the long run impact of agricultural exports on growth performance in Nigeria. The study covers the periods between 1980 and 2010. The underlying models are the Export- Led Growth Hypothesis and the Neo-classical Growth Model. In the formulated model, Real Gross Domestic Product was used as the proxy for economic growth. The explanatory variables used were Gross Fixed Capital Formation, Labour force, Foreign Direct Investment and Agricultural exports. The study made use of unit root tests and Johansen Maximum Likelihood Test of Co-Integration. It was discovered that a long run equilibrium relationship exists between agricultural exports and economic growth and the relationship is elastic in nature meaning that a unit increase in agricultural exports would bring a more than proportionate increase in the Real Gross Domestic Product in Nigeria. Keywords: Agricultural exports, economic growth, Real Gross Domestic Produc

A systematic review on COVID-19 pandemic with special emphasis on curative potentials of Nigeria based medicinal plants

Despite the frightening mortality rate associated with COVID-19, there is no known approved drug to effectively combat the pandemic. COVID-19 clinical manifestations include fever, fatigue, cough, shortness of breath, and other complications. At present, there is no known effective treatment or vaccine that can mitigate/inhibit SARS-CoV-2. Available clinical intervention for COVID-19 is only palliative and limited to support. Thus, there is an exigent need for effective and non-invasive treatment. This article evaluates the possible mechanism of actions of SARS-CoV-2 and present Nigeria based medicinal plants which have pharmacological and biological activities that can mitigate the hallmarks of the pathogenesis of COVID-19. SARS-CoV-2 mode of actions includes hyper-inflammation characterized by a severe and fatal hyper-cytokinaemia with multi-organ failure; immunosuppression; reduction of angiotensin-converting enzyme 2 (ACE2) to enhance pulmonary vascular permeability causing damage to the alveoli; and further activated by open reading frame (ORF)3a, ORF3b, and ORF7a via c-Jun N- terminal kinase (JNK) pathway which induces lung damage. These mechanisms of action of SARS-CoV-2 can be mitigated by a combination therapy of medicinal herbs based on their pharmacological activities. Since the clinical manifestations of COVID-19 are multifactorial with co-morbidities, we strongly recommend the use of combined therapy such that two or more herbs with specific therapeutic actions are administered to combat the mediators of the disease.publishedVersionFil: Oladele, Johnson O. Kings University; Nigeria.Fil: Ajayi, Ebenezer Idowu O. Osun State University; Nigeria.Fil: Ajayi, Ebenezer Idowu O. Universidad Nacional de Córdoba. Rectorado; Argentina.Fil: Ajayi, Ebenezer Idowu O. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra.; Argentina.Fil: Oyeleke, Oyedotun M. Kings University; Nigeria.Fil: Oladele, Oluwaseun T. Osun State University; Nigeria.Fil: Olowookere, Boyede D. Kings University; Nigeria.Fil: Adeniyi, Boluwaji M. Benue State University; Nigeria.Fil: Oyewole, Olu I. Osun State University; Nigeria.Fil: Oladiji, Adenike T. University of Ilorin; Nigeria