Enhancing Strength Properties of Rubberized Concrete using Waste Cement Sacks

Low flexibility and brittleness of ordinary concrete limits its use as construction material for buildings prone to earthquake ground vibrations. Rubberized concrete which possesses the needed ductility on the other hand is however of low strength and durability. This study utilized waste polypropylene sacks used for packaging cement. The sacks were used in form of confinements to enhance the strength/ductility of rubberized concrete. Concrete cylinders, cubes and beams at different replacements levels of coarse aggregate with waste tire rubber chips(WTRC) (at 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% by volumes) were cast and tested for fresh and hardened properties such as slump, compressive strength, flexural strength, and deformation behaviour. The result showed proportional reduction in strengths with increasing replacement of WTRC. Ductile and elasto-plastic deformations were exhibited by WTRC concretes. The use of waste cement sacks confinement as a means of overcoming the reduced strength of the rubberized concrete proved highly feasible and economic for the cylindrical specimens. Optimum performance in failure load (for confined specimens) was obtained at 80% WTRC replacement. The confined 80% WTRC failure load was 45.5 KN, approximately 300% increase in failure load of the unconfined 80% WTRC concrete. This indicates that the use of waste cement sacks to confine rubberized concrete effectively negates the decrease in strength, and retains the advantages of increased ductility and energy-dissipation that characterizes rubberized concrete

Human Immunodeficiency Virus Self‑Testing: Perspectives from Primary Healthcare Workers in Enugu State, Southeast Nigeria

Background: Stigmatization remains an intractable issue surrounding human immunodeficiency virus (HIV) management. Testing services are the gateway to treatment and prevention. HIV‑self testing (HIVST) is a panacea to this stigmatization. It is a simple friendly testing technique. This study assessed issues surrounding the HIVST from the perspectives of the primary health‑care workers in Enugu State. Methods: A cross‑sectional study was carried out using a semi‑structured interviewer‑administered questionnaire. A convenience sampling of 238 respondents were sampled from the 17 local government areas of the state. Analyses were performed using IBM‑SPSS version 23. Ethical approval was obtained from the Enugu State Ministry of Health. Results: The majority of the respondents were within the age of 31–50 years 84 (35.3%), predominantly females 203 (85.3%) and mainly married 191 (80.3%). Half of them had practiced for over 10 years and 145 (60.9%) had good knowledge of HIV screening. However, 23.9% understood HIVST as a  testing modality approved by the World Health Organization. A handful of them, 25 (10.5%) correctly identified the 5Cs of HIV testing. Only 162 (68.1%) of the health‑care workers reported stigma as the most perceived problems of the present testing modality and 146 (61.3%) expressed a  preference for HIVST over previous methods. Age was found to be a determinant of good knowledge of HIVST, as being within the age group of  20–40 years has a 1.83 greater odds of good knowledge of HIVST than, 41–60 years age group (Adjusted odds ratios = 1.830; 95% confidence interval  1.081–3.099). Conclusion: Most of the Primary health‑care workers in Enugu State had poor knowledge of HIVST. These workers could benefit from awareness creation and training on HIVST by public health specialists to improve their knowledge. Keywords: Enugu state, human immunodeficiency virus self‑testing, perspectives, primary health‑care worker

Ethanolic extract of Annona muricata leaf and its effect on the liver

The effect of ethanolic extract of Annona muricata leaf on the liver of albino rats were investigated in this study. Twenty (20) male albino rats weighing between 180-200 g were used in this study. The animals were divided into groups A, B, C and D. Group A was treated with 2 ml/kg body weight of distilled water, Group B was treated with 100 mg/kg body weight of the extract, Group C was treated with 200 mg/kg body weight of the extract and Group D was treated with 300 mg/kg body weight of the extract. The treatments were given orally and lasted for a period of 30 days. After the last day of treatment, the animals were sacrificed and the liver harvested, weighed and fixed in 10% formal saline for histological studies. Blood samples were collected through cardiac puncture for biochemical analysis. Data were analysed using one-way ANOVA and SPSS version 2.0. Results showed a significant (P<0.05) increase in liver weight when compared to control and a significant (P<0.05) increase in serum levels of ALP, ALT and AST at highest dose. Histopathological findings showed distortions of the liver cytoarchitecture with the highest dose having a more significant effect. Consumption of ethanolic extract of A. muricata leaf at higher doses has the potential of causing liver damage. Thus, its consumption should be regulated or better still taken at lower doses. Keywords: Annona muricata; Liver; Liver enzymes; Albino rat

The Luminosity Function of Low-Redshift Abell Galaxy Clusters

We present the results from a survey of 57 low-redshift Abell galaxy clusters to study the radial dependence of the luminosity function (LF). The dynamical radius of each cluster, r200, was estimated from the photometric measurement of cluster richness, Bgc. The shape of the LFs are found to correlate with radius such that the faint-end slope, alpha, is generally steeper on the cluster outskirts. The sum of two Schechter functions provides a more adequate fit to the composite LFs than a single Schechter function. LFs based on the selection of red and blue galaxies are bimodal in appearance. The red LFs are generally flat for -22 < M_Rc < -18, with a radius-dependent steepening of alpha for M_Rc > -18. The blue LFs contain a larger contribution from faint galaxies than the red LFs. The blue LFs have a rising faint-end component (alpha ~ -1.7) for M_Rc > -21, with a weaker dependence on radius than the red LFs. The dispersion of M* was determined to be 0.31 mag, which is comparable to the median measurement uncertainty of 0.38 mag. This suggests that the bright-end of the LF is universal in shape at the 0.3 mag level. We find that M* is not correlated with cluster richness when using a common dynamical radius. Also, we find that M* is weakly correlated with BM-type such that later BM-type clusters have a brighter M*. A correlation between M* and radius was found for the red and blue galaxies such that M* fades towards the cluster center.Comment: Accepted for publication in ApJ, 16 pages, 4 tables, 24 figure

The Kinematics of Intracluster Planetary Nebulae and the On-Going Subcluster Merger in the Coma Cluster Core

The Coma cluster is the richest and most compact of the nearby clusters, yet there is growing evidence that its formation is still on-going. With a new multi-slit imaging spectroscopy technique pioneered at the 8.2 m Subaru telescope and FOCAS, we have detected and measured the line-of-sight velocities of 37 intracluster planetary nebulae associated with the diffuse stellar population of stars in the Coma cluster core, at 100 Mpc distance. We detect clear velocity substructures within a 6 arcmin diameter field. A substructure is present at ~5000 km/s, probably from in-fall of a galaxy group, while the main intracluster stellar component is centered around ~6500 km/s, ~700 km/s offset from the nearby cD galaxy NGC 4874. The kinematics and morphology of the intracluster stars show that the cluster core is in a highly dynamically evolving state. In combination with galaxy redshift and X-ray data this argues strongly that the cluster is currently in the midst of a subcluster merger, where the NGC 4874 subcluster core may still be self-bound, while the NGC 4889 subcluster core has probably dissolved. The NGC 4889 subcluster is likely to have fallen into Coma from the eastern A2199 filament, in a direction nearly in the plane of the sky, meeting the NGC 4874 subcluster arriving from the west. The two inner subcluster cores are presently beyond their first and second close passage, during which the elongated distribution of diffuse light has been created. We predict the kinematic signature expected in this scenario, and argue that the extended western X-ray arc recently discovered traces the arc shock generated by the collision between the two subcluster gas halos. Any preexisting cooling core region would have been heated by the subcluster collision.Comment: Astronomy & Astrophysics, in press, 9 pages, 5 figure

Factors affecting willingness to comply with public health measures during the pandemic among sub-Sahara Africans

Background: The unprecedented outbreak of coronavirus disease (COVID-19) drastically spread worldwide, resulting in extraordinary measures put in place in various countries including Sub Saharan Africa (SSA) countries. Objective: To assess the factors associated with compliance with the public health measures imposed by various SSA countries. Method: Cross sectional study using self-administered surveys distributed on social media platforms between April 18th and May 16th, 2020, corresponding with the mandatory lockdown period in most SSA countries. Multivariate analysis examined the associated factors. Results: The prevalence of hand hygiene, quarantine, self isolation practices, wearing of face mask and attending large gatherings during COVID-19 were 94%, 39%, 31%, 64% and 14%, respectively. In multivariate models, older age 49+ years: adjusted OR 2.13, 95%CI 1.22,3.71), females (OR 1.41,95%CI 1.03,1.93), Central African countries (OR 3.73,95%CI 2.02,6.87) were associated with wearing face mask. Living alone (aOR 1.52,95%CI 1.04,2.24) during the lockdown was associated with avoiding large gatherings including religious events. Female respondents (aOR 1.61, 95%CI 1.30, 2.00), married (aOR 1.71,95%CI 1.33,2.21) and unemployed (aOR 1.62,95%CI 1.25,2.09) SSAs were more likely to practice self-quarantine measures. Conclusion: The low prevalence of mitigation practices suggest the need for targeted education campaign programs to sensitise the population

COVID-19 in Sub-Saharan African countries : association between compliance and public opinion

Background: The outbreak of coronavirus disease (COVID-19) has created a global public health crisis and non-compliance with public health measures to contain the infection poses a challenge to Sub-Saharan African governments. This study investigated the associations between compliance and public opinion on COVID-19 public health containment measures across selected SSA countries. Method: Anonymous online cross-sectional survey was administered to 1779 adults (18 years and older) during the mandatory lockdown period in most African countries (April 18 - May 16, 2020). Respondents were recruited via Facebook, WhatsApp, and authors' networks. Data on participants’ socio-demographics, their opinions regarding the precautionary measures against COVID-19, and their compliance with preventive measures were collected. Multiple logistic regression analysis was used to examine the association between compliance and public opinions about COVID-19. Results: Respondents who did not think that public health authorities in their countries were doing enough to control the C0VID-19 outbreak were more likely to attend crowded places (aOR 1.75, 95% CI 1.30-2.35). Those who thought COVID-19 would not remain in their countries (aOR 0.48, 95% CI 0.24 - 0.96) and those who thought self-isolation is not needed during the pandemic (aOR 0.29, 95% CI 0.13 - 0.65) were less likely to encourage others to comply with the strategies put in place to prevent the spread of the disease. Participants who thought the COVID-19 outbreak was dangerous and those wearing medical masks were found to wash their hands with soap under running water. Conclusion: The study showed that public opinion influenced the compliance of individuals to public health measures for containment and mitigation of COVID-19. There is a need to improve compliance by the public

Public awareness and perception towards COVID-19 in sub-saharan African countries during the lockdown

Background: The coronavirus disease (COVID-19) outbreak has caused a universal health crisis resulting in significant morbidities and mortalities particularly among high-risk groups. This study sought to determine regional factors associated with knowledge and attitude towards COVID-19 mitigation practices and risk perception of contracting the disease in Sub-Saharan African (SSA) countries. Methods: A cross-sectional anonymous online study was conducted among 1970 participants between April and May 2020, during the lockdown in many SSA countries. Recruitment of participants was via WhatsApp, Facebook and emails using authors’ networks. The outcome variables were KAP (knowledge, attitudes and practice) of COVID-19 and analysis of variance (ANOVA) with post hoc test was run to assess the level of KAP by four regions in SSA. Simple and multiple linear regression (MLR) analyses were performed to examine factors associated with the outcome measures in the four SSA regions. Results: Mean knowledge (P=0.707) and risk perception (P=0.904) scores by four regions in SSA did not differ significantly. However, the mean attitude score was higher among West Africans compared with Southern (P=0.019) and Central Africans (P=0.003). MLR analysis revealed that among those living in West (adjusted coefficient β=-0.83 95% CI: -1.19, -0.48) and Southern Africa (β=-0.91 95% CI: -1.42, -0.40), having a primary or secondary education was associated with a decrease in knowledge scores while not being worried about COVID-19 decreased risk perception scores across the four SSA regions(West [β=-6.57, 95% CI: -7.53, -5.62], East [β=-6.24: 95% CI: -8.34,-4.15], Central [β=-6.51, 95% CI: -8.70, -4.31], and Southern Africa [β=-6.06: 95% CI: -7.51, -4.60]). Except among Southern Africans, participants who practiced self-isolation had positive attitude towards COVID-19. Conclusion: Future research on health education regarding COVID-19 or a future related pandemic in SSA should target people with lower education, those who do not self-isolate, those living in Southern and Western Africa and not worried about contracting COVID-19