Mechanisms of ischaemic protection in humans

Reperfusion limits ischaemic tissue damage. Paradoxically, reperfusion can cause additional tissue injury and contribute to a composite phenomenon known as ischaemia reperfusion (IR) injury. Therapeutic interventions aimed at reducing IR injury have the potential to improve outcomes in the management of ischaemic conditions. Protective procedures such as ischaemic preconditioning (IPC), ischaemic postconditioning (PostC), remote preconditioning (RIPC) and remote postconditioning (RPostC) have all been shown in animals and humans to be effective in reducing IR injury. Experiments in this thesis sought to determine tractable aspects of the mechanisms underlying these protective phenomena with a view to validating potential pharmacological targets in humans. IR induced endothelial dysfunction in the forearm of healthy volunteers was characterised by vascular ultrasound and venous occlusion plethysmography. IPC, PostC, RIPC and RPostC all protected against IR-induced endothelial dysfunction. Oral inorganic nitrates in the form of beetroot juice or potassium nitrate (KNO3) also protected against endothelial IR injury. The magnitude of protection from IR injury was similar. The mechanism of PostC was investigated in detail. Protection by PostC was blocked by glibenclamide, a non selective KATP channel blocker, suggesting that activation of these potassium channels was necessary for PostC-induced ischaemic protection. Selectivity of KATP channels was evident because glimepiride (a selective KATP channel blocker) did not affect the protective effect of PostC. A role for the mitochondrial permeability transition pore (mPTP) was suggested by the effect of ciclosporin (blocker of the mPTP) to mimic PostC-induced protection. These aspects of the mechanism of PostC resemble previously identified mechanisms of IPC and RIPC in the human forearm. Studies were undertaken to explore the mechanism whereby protection spreads systemically. Systemic protection by RIPC from ischaemic injury to the endothelium was blocked by the opioid receptor antagonist, naloxone without any effect on protection conferred by IPC or RPostC These data implicate the opioid receptor pathway in the facilitation of RIPC, and is likely to involve a haematogenous mechanism. Conversely, the alpha adrenergic receptor antagonist phentolamine, blocked systemic protection from RPostC but had no effect on RIPC. This highlights a role of a component of the autonomic nervous system in the mediation of RPostC. Ischaemic protection in humans is mechanistically a complex process but results in this thesis contribute to the validation of pharmacological targets as a prelude to drug development

Retinoblastoma: a most unusual presentation – Case report

Background: Retinoblastoma is the most common intraocular tumour in children, with the average age at diagnosis varying from 12 months in bilateral cases to 23 months for unilateral tumours. Extraocular disease has a far lower survival rate than the intraocular one. In the developed world, more than 90% of patients with retinoblastoma survive, however in the developing world, where retinoblastoma exists primarily as anextraocular disease, relatively few patients survive because of late presentation and paucity of treatment options. 2 Presented here is the case report of a 41/ -month old male Nigerian baby, who presented with a 2-week history of rapidly progressive painful proptosis of the right eye. Examination revealed a firm fungating mass arising from the right orbitwhich had pushed the globe supero-nasally. There was severe right lower lid oedema and marked conjunctival chemosis inferiorly, but the cornea was clear. The patient also had right leukocoria. The left eye was normal. An ultrasound scan showed a huge right ocular tumour, solid in consistency with heterogeneous architecture, which appeared to be growingfrom the superior margin of the globe; the finding was reported to be consistent with retinoblastoma. Due to the rapidly progressive and necrotic nature of the tumour, a lid-sparing modified exenteration was done. Thehistopathology findings were consistent with a diagnosis of undifferentiated retinoblastoma. About two weeks after surgery there was tumour recurrence but this regressed following commencement of chemotherapy by the paediatric oncology unit.The tumour recurred despite aggressive chemotherapy and the patient eventually died 6 months later. Conclusion: Retinoblastoma in Third World countries is still a fatal disease, unlike in developed countries where it has a survival rate of over 90%. Poverty and non availability ofsophisticated diagnostic tools make early detection difficult thus increasing mortality from the disease.Key words: retinoblastoma, congenital, unilateral, rapidlyprogressiv

UK medical students’ perspectives on practical prescribing teaching and learning provisions: a cross-sectional survey

Purpose To determine medical students’ perspectives on the provision for the teaching and learning of processes that lead to and include the writing of a clear, safe and legal prescription (practical prescribing) in UK medical schools. Methods We designed a cross-sectional survey of UK medical students in years three, four and five. Students were asked about their experiences and views of practical prescribing teaching and learning they had encountered on their medical course. Results A total of 1023 medical students responded (7% response rate), from 25 UK medical schools: 22%, 37% and 41% in the third, fourth and final years, respectively. Teaching of practical prescribing was widespread, with 94.3% of final year (n = 396, 95% confidence interval [CI] = 92–97%), 86.8% of fourth year (n = 328, CI = 83–90%) and 73.8% of third year (n = 166, CI = 67–80%) students reporting they had received it. Availability of this teaching appeared to vary by medical school. Self-directed learning was the most frequently reported mode of delivery (90.9%, n = 809). Validated pre-prescribing and simulation were perceived by students in each year group as the most effective methods. Clinical pharmacologists, clinical pharmacists and junior doctors were perceived by the students as being the most effective professional groups at teaching practical prescribing. Conclusions UK medical students reported a variety of methods utilised in the teaching and learning of practical prescribing. However, methods they perceived to be very effective (simulation and pre-prescribing) do not appear to be widely available or are only reserved for the final year of study. Combining such methods with involvement of professional groups perceived to be most effective should be explored

Work Environment and Employeesa Commitment in Agro-Based Industries in Cross River State, Nigeria

This study examines the effect of work environment on employees commitment in agro-based industries in Cross River State Nigeria The study drew participants from two major agro industries in the state One thousand one hundred and ninety four 1194 respondents were purposively selected for the study Information was elucidated from participants using four point Likert scale questionnaire Data obtained was analyzed using Pearson product moment correlation r Findings revealed that work environment such as consistent communication flow manageable workload availability of electricity and work place that is free from known dangers are positively associated with employees commitment and hence performance The study recommended among others that management of agro-based industries in Cross River State should establish and promote good work environments in their organizations so as to boost employees commitment wellbeing and overall performance and productivit

Effects of different three live foods on growth performance and survival rates in beluga (Huso huso) larvae

To determine the best live food and to reevaluate the optimal weaning period for beluga fish (Huso huso) larvae, seven experimental diets: Daphina (DP), Chironomids (CH), Gammarid (G), Daphina + formulated diet (DPFD), Chironomids + formulated diet (CHFD), Gammarid + formulated diet (GFD ) and formulated diet (FD) in triplicate groups were fed to 4662 sixteen-days-old larvae which were captured from the stock tank and randomly distributed into 21 tanks. The microdiets contained 48-50% crude protein, 12-13% crude fat, 9-11% moisture and 8.5-9.5% ash . After 25 days feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed CHFD were significantly higher than those of fish fed the other diets ( P< 0.05). Frequent cannibalism and higher mortality in larvae fed G, GFD and FD diets were observed. These results may show the importance of live food followed by formulated diets in a gradual application pattern, as early as on the fourth to fifth day after hatching

Teaching Method and Assimilation of Students in Tertiary Institutions: A Study of Covenant University,Nigeria

The choice of teaching method which is the general principles, pedagogy and management strategies used for classroom instruction is very important to degree of assimilation by the recipient of teaching. Teaching theories primarily fall into two categories or “approaches” teacher-centered and studentcentered. In the former, teachers are the main authority figure in this model. Students are viewed as empty vessels whose primary role is to passively receive information (via lectures and direct instruction) with an end goal of testing and assessment. However in a student-centered approach, teachers and students play an equally active role in the learning process. The teacher’s primary role is to coach and facilitate student learning and overall comprehension of material. Student learning is measured through both formal and informal forms of assessment, including group projects, student portfolios, and class participation. The main aim of this paper is to examine the relationship between teaching method and assimilation of students and the impact on examination performance. A sample of 300 students cutting across the various schools and colleges in Covenant University who have taken at least not less than two semesters examinations was used for the study. Student-Lecturer relationship, examination contents, students’ mode of study and assimilation, effort and students’ CGPA were the parameters used for this purpose

Gender Analysis of Socio-Cultural Perception of \u3cem\u3eMoringa Oleifera\u3c/em\u3e Amongst Farmers in Southwestern Nigeria

Moringa oleifera (horseradish tree - English) is a perennial plant, which has been found to possess high economic and cultural values in many countries of the world. This study was carried out to analyse the socio-cultural perception about Moringa oleifera according to farmers’ gender in Southwestern Nigeria. It specifically established the correlates of perception of Moringa oleifera among the farmers; described the socio-demographics of the farmers; examined the gender gaps in the level of awareness and propagation of Moringa oleifera; compared their willingness to adopt innovation on Moringa oleifera and analysed the constraints associated with men’s and women’s propagation of Moringa oleifera. A snow-ball sampling technique was used to select equal number of male and female respondents across the region. The results revealed amongst others, that widowhood and illiteracy were the likely interlocking system, which has reshaped oppression among the female respondents. Statistically significant gender gaps or inequalities at P ≤ 0.05 level, existed in the level of awareness (F = 6.29), propagation (F = 15.56), willingness to adopt innovation (F = 12.61) and socio-cultural perception of Moringa oleifera (F = 11.34). The study concluded that the gender differential gaps could reverse the gains of innovations on Moringa oleifera by limiting the adoption of innovation and propagation of the plant among the farm families. It, therefore, recommended that the generated innovations should be properly screened to ensure that they do not upset the delicate economic power balance between men and women in the farming sector or widen the gender inequalities or create other vectors of oppression. So, policies that encourage women’s literacy as well as access to innovations and farm labour, most especially amongst the widows are indispensable in enhancing socio-cultural perceptions and adoption of innovation as well as propagation of Moringa oleifera for sustainable development in Southwest Nigeria

Simulation to enable a data-driven circular economy

This is the final version. Available on open access from MDPI via the DOI in this record.The underlying data can be accessed at 10.15131/shef.data.8246912This paper presents an investigation on how simulation informed by the latest advances in digital technologies such as the 4th Industrial Revolution (I4.0) and the Internet of Things (IoT) can provide digital intelligence to accelerate the implementation of more circular approaches in UK manufacturing. Through this research, a remanufacturing process was mapped and simulated using discrete event simulation (DES) to depict the decision-making process at the shop-floor level of a remanufacturing facility. To understand the challenge of using data in remanufacturing, a series of interviews were conducted finding that there was a significant variability in the condition of the returned product. To address this gap, the concept of certainty of product quality (CPQ) was developed and tested through a system dynamics (SD) and DES model to better understand the effects of CPQ on products awaiting remanufacture, including inspection, cleaning and disassembly times. The wider application of CPQ could be used to forecast remanufacturing and production processes, resulting in reduced costs by using an automatised process for inspection, thus allowing more detailed distinction between “go” or “no go” for remanufacture. Within the context of a circular economy, CPQ could be replicated to assess interventions in the product lifecycle, and therefore the identification of the optimal CE strategy and the time of intervention for the current life of a product—that is, when to upgrade, refurbish, remanufacture or recycle. The novelty of this research lies in investigating the application of simulation through the lens of a restorative circular economic model focusing on product life extension and its suitability at a particular point in a product’s life cycle.Engineering and Physical Sciences Research Council (EPSRC)Royal Academy of Engineering (RAEng)Airbu

Necessity of Paradigm Shift in Criminological Theorizing

The traditional linkage of defective educational acquisition and the propensity to engage in antisocial behaviours has been accentuated in criminological theory. However, current development in ICT environment preferred for spacelessness, timelessness with its unchanging requirement for ingenuity in the use and mastery of e-interaction has consistently queried the veracity of defective education and crime participation. A survey on cyber fraud conducted in Nigeria found out that the acquisition of requisite education is central to technology-driven crime participation and guarantees continual survival and career longevity in crime business. Consequently, this article analyses the necessity of educational acquisition for crime participation and further advocated for a paradigm shift to accommodate the changing trends in the education-crime symbiotic relationship in the ICT age. This is germane to criminology of ICT in capturing and mitigating the victimization that are contactable through participation in e-relationship

Biosynthesis of silver nanoparticles in improved strain of Auricularia polytricha -an edible mushroom from Nigeria and its antimicrobial activities

Nano materials and their application are of great use in research because of their size range. In this study, Auricularia polytricha (EW1) collected from Benin in Southern Nigeria was subjected to mutation by exposure to UV-light resulting in a mutant (EW1M1). EW1 and EW1M1 were evaluated for biosynthesis of silver nano-particles. The anti-microbial properties of both strains were also evaluated. Absorption spectra of silver nano-particle (AgNPs) of mutant exhibited a strong broad peak at 420 nm while wild type absorption peak was obtained at less than 420 nm. The mutant was further characterised. DLS showed a monodispersion with diverse sizes, morphology and shapes. TEM micrograph revealed a monodispersed formation of the nano-particles, with uniform size at 10 – 20 nm. FTIR study revealed the absorption bands at 3380, 2921, 2839, 1658, 1083 and 610 cmֿ1 respectively showing the functional groups reducing the silver nitrate to silver ion. There was formation of zone of inhibition on all the microorganisms that were used for the study but the control showed no zone of inhibition. The mushroom extract of mutant strain exhibited higher anti microbial activity than the wild type