Assessment of Reliability and Availability of Series-Parallel Sub-Systems

The paper presents the explicit expressions for measuring reliability parameter  of systems, Graphs were plotted to highlight important results. Results have shown that measures of system effectiveness such MTSF, system availability and profit increases with repair rates and decreases with failure rates.The developed model helps in determining the optimal maintenance strategies which ensure the maximum overall availability of the system. The optimum values of failure and repair rates for each subsystem were given. It is observed that the first subsystem is having the maximum availability with (97%). The optimum values of failure and repair rates for maximum availability level for each subsystem is also shown. Keywords: Mean time to system failure, Availability, Reliability, Maintenance and Subsystem

Aggregate Demand for Micro-insurance among Rural Household Non-farm Enterprises in Nigeria

Although, rural based enterprises are subject to a myriad of risks and economic shocks, insurance uptake has been found to be abysmally low. The aim of this study was to examine the determinants of demand for insurance from the standpoint of the rural based household non-farm enterprises (RHNFE). This study made use of the household non-farm enterprise data from the LSMS- General Household Survey of 2010/2011. Demand for insurance was measured as the monthly expenditure on insurance by the RHNFE. The empirical findings indicate that RHNFE were mainly informal in nature with low level investment, and low labour requirement. Consequently, there is relatively high production/transactions costs relative to revenue. Premium paid for insurance was found to be very low and determined by the value placed on the system, access to market for operation as well as the scope of operation of the businesses. Access to market infrastructure and opportunities for standardizing products area recommended in order for the RNFE to take advantage of insurance targeted towards them. Keywords: Microinsurance, Demand, Rural, Non-farm enterprises, Nigeri

Relationship between serum level of ionized calcium, magnesium, phosphate, vitamin d and parathyroid hormone with stages of CKD.

Chronic kidney disease is defined as either damage or a decreased Glomerular Filtration Rate of less than 60ml/min/1.73m for 3 or more months. There is destruction of renal mass with irreversible sclerosis and loss of nephron leading to a progressive decline in GFR.Secondary hyperparathyroidism hyperphosphataemia, hypocalcaemia and vitamin-D deficiency are common complications of CKD. Objective: To determine relationship between serum level of ionised calcium, magnesium, phosphate, vitamin-D and parathyroid hormone with stages of CKD. Method: This study was conducted at ABUTH Zaria. 125 consecutive adult patients in various stages of CKD who presented were enrolled and 125 apparently healthy matched for sex and age controls were also recruited. Results: 9% of patients were in stage-1, 16% in stage-2, 22% in stage-3, 12% in stage-4 and 41% in stage-5. Serum ionised calcium, vitamin-D and eCrCl showed a progressive decline as the stage of CKD advances, while serum phosphate, creatinine and iPTH showed a progressive increase as the stage of CKD advances. Changes in serum magnesium showed a slight change with advancing stages of CKD. The difference in mean serum levels of calcium, phosphorus, vitamin-D, parathyroid hormone, creatinine and eCrCl with different stages of CKD were statistically significant. eCrCl correlated negatively with phosphate and iPTH while serum creatinine correlated negatively with calcium and positively with phosphate and iPTH. Conclusion: Majority of CKD patients were in late stage. Correlation of analytes with stages was more in late stages and biochemical derangements occurred in late, rather than early stages of CKD

Rapid Assessment of Polio Virus Antibodies Prevalence Amongst Children in Kano State, North West Nigeria

The completion of poliomyelitis eradication is a global health emergency which must be pursued with vigour. Kano state has remained one of the epicenters for polio virus outbreaks in northern Nigeria. There is paucity of information as it relates to polio antibody prevalence amongst children in the state. Periodic serologic assessment is needed to determine the quality and effectiveness of routine vaccination campaigns carried in the state to rapidly build immunity against poliovirus. Children were randomly selected throughout the state for the assessment between Sept. 2013 and Jan. 2014. Blood samples were collected from eighty children and tested for the presence of antibodies to the three poliovirus serotypes. Indirect ELISA was used to rapidly screen for the antibodies. Epi Info 3.5.4 version was used for the data analysis. Out of the samples collected, 61 (76.3%) had antibodies to all the serotypes. While 73 (91.3%), 66 (82.5%) and 72 (90%) had antibodies to virus serotypes 1, 2 and 3 respectively. Age of the children, number of doses the children had taken and educational level of the children’s fathers were statistically significant risk factors on the prevalence of poliovirus antibodies. Access to immunization services must be improved in urban and rural areas so as to effectively reach a large number of children in those places. Effective and high quality campaigns are needed so that every eligible child is reached. Greater focus on good mobilization is also needed to reach children in households in rural areas as well as in households with children whose fathers’ educational level was low.Keywords: Kano, Prevalence, Children and Polio-antibod

Aniline-Driven Liquid-Liquid Extraction for Methylamine-Water Separation: Process Simulation and Performance Evaluation

Methylamines are toxic with ammonia-like odor while aniline has a fishy odor. Both aniline and methylamines affect aquatic life and water quality if present in large concentrations in water. Nevertheless, the later, with solubility of 1120 g/L is more soluble in water than the former with solubility of 3.6 g/L at 25. Based on their difference in solubilities, liquid-liquid extraction (LLE) technique can be used to separate or remove the presence of any one of the two pollutants in water. The UNIQUAC property method in Aspen Plus V8.8 was proven to be the best method for the LLE of a water-aniline-methylamine ternary mixture after a single stage partition coefficient analysis with a mixing tank. Adopting the best model for a two-stage separation using ‘Extract’ and ‘RadFrac’ Aspen Plus model units, yielded three separate product streams that are 95.5% methylamine, 86.5% aniline and 100% water. The phase boundary, diagonal tie lines and a constant boiling point of 372.505 K showcased by the ternary phase diagram demonstrated the presence of an azeotrope and the ability of the RadFrac model to separate the mixture easily. Future demonstration on how to separate numerous ternary mixtures is recommended, as the need to treat effluents of many industries containing compounds of varying solubilities may warrant the setting up of a LLE unit. &nbsp

Fixed points for cyclic R-contractions and solution of nonlinear Volterra integro-differential equations

In this paper, we introduce the notion of cyclic R-contraction mapping and then study the existence of fixed points for such mappings in the framework of metric spaces. Examples and application are presented to support the main result. Our result unify, complement, and generalize various comparable results in the existing literature.http://link.springer.com/journal/11784am2016Mathematics and Applied Mathematic

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity