A critical evaluation of students' attitudes to electronic learning at the University of Chester

The research described in this thesis reports the results of a study into the adoption of e-learning strategies based on the use of the World Wide Web (WWW) and Internet. Through an extensive and critical literature review, it exemplifies how higher education uses intranets to deliver learning and support services to their student population. The overall aim of this research was to investigate how e-learning at the University of Chester might more effectively support students' learning needs, thereby improving their experience of e-learning. Students were given a mode of study, either face-to-face (64 subjects) or experimental using online intranet delivery (66 subjects). The course used for this study was a 13 week, Level Two undergraduate computer course taken by non-computing students. Quantitative and qualitative data were collected and analysed. The results reveal significant differences between the performance of the e-learning and face-to-face groups with e-learning students performing poorly when compared to their face-to-face peers. A lack of responsiveness in tutor support and student motivation were established as being major contributing factors as well as differences in the students' individual learning profiles. The research concludes that e-learning, although promoted as being anytime and anywhere is limited in its flexibility and responsiveness in the context in which it was assessed. Most e-learning activities at the University of Chester can be described as 'one size fits all'. They require students to read printed text, carry out further work, research or exercises, and post written comments to a discussion board. There is little evidence that individual student needs and preferences are being considered or supported. With the move towards blended learning in educational institutions, e-learning strategies are being used as a regular part of the curriculum to enhance the student experience. This research provides alternatives for the development and delivery of more individually tailored e-learning courses and provides strategies for supporting students in virtual environments more effectively. The thesis concludes by proposing a new model for e-learning based on these results coupled with a self-critical review and proposals for further research.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Efficacy and safety of zibotentan and dapagliflozin in patients with chronic kidney disease: study design and baseline characteristics of the ZENITH-CKD trial

Background: Sodium–glucose co-transporter 2 inhibitors (SGLT2is) are part of the standard of care for patients with chronic kidney disease (CKD), both with and without type 2 diabetes. Endothelin A (ETA) receptor antagonists have also been shown to slow progression of CKD. Differing mechanisms of action of SGLT2 and ETA receptor antagonists may enhance efficacy. We outline a study to evaluate the effect of combination zibotentan/dapagliflozin versus dapagliflozin alone on albuminuria and estimated glomerular filtration rate (eGFR). // Methods: We are conducting a double-blind, active-controlled, Phase 2b study to evaluate the efficacy and safety of ETA receptor antagonist zibotentan and SGLT2i dapagliflozin in a planned 415 adults with CKD (Zibotentan and Dapagliflozin for the Treatment of CKD; ZENITH-CKD). Participants are being randomized (1:2:2) to zibotentan 0.25 mg/dapagliflozin 10 mg once daily (QD), zibotentan 1.5 mg/dapagliflozin 10 mg QD and dapagliflozin 10 mg QD alone, for 12 weeks followed by a 2-week off-treatment wash-out period. The primary endpoint is the change in log-transformed urinary albumin-to-creatinine ratio (UACR) from baseline to Week 12. Other outcomes include change in blood pressure from baseline to Week 12 and change in eGFR the study. The incidence of adverse events will be monitored. Study protocol–defined events of special interest include changes in fluid-related measures (weight gain or B-type natriuretic peptide). // Results: A total of 447 patients were randomized and received treatment in placebo/dapagliflozin (n = 177), zibotentan 0.25 mg/dapagliflozin (n = 91) and zibotentan 1.5 mg/dapagliflozin (n = 179). The mean age was 62.8 years, 30.9% were female and 68.2% were white. At baseline, the mean eGFR of the enrolled population was 46.7 mL/min/1.73 m2 and the geometric mean UACR was 538.3 mg/g. // Conclusion: This study evaluates the UACR-lowering efficacy and safety of zibotentan with dapagliflozin as a potential new treatment for CKD. The study will provide information about an effective and safe zibotentan dose to be further investigated in a Phase 3 clinical outcome trial. // Clinical Trial Registration Number: NCT0472483

A Gene-Based Association Method for Mapping Traits Using Reference Transcriptome Data

Genome-wide association studies (GWAS) have identified thousands of variants robustly associated with complex traits. However, the biological mechanisms underlying these associations are, in general, not well understood. We propose a gene-based association method called PrediXcan that directly tests the molecular mechanisms through which genetic variation affects phenotype. The approach estimates the component of gene expression determined by an individual’s genetic profile and correlates ‘imputed’ gene expression with the phenotype under investigation to identify genes involved in the etiology of the phenotype. Genetically regulated gene expression is estimated using whole-genome tissue-dependent prediction models trained with reference transcriptome data sets. PrediXcan enjoys the benefits of gene-based approaches such as reduced multiple-testing burden and a principled approach to the design of follow-up experiments. Our results demonstrate that PrediXcan can detect known and new genes associated with disease traits and provide insights into the mechanism of these associations

Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects

Expression and trans-specific polymorphism of self-incompatibility RNases in Coffea (Rubiaceae)

Self-incompatibility (SI) is widespread in the angiosperms, but identifying the biochemical components of SI mechanisms has proven to be difficult in most lineages. Coffea (coffee; Rubiaceae) is a genus of old-world tropical understory trees in which the vast majority of diploid species utilize a mechanism of gametophytic self-incompatibility (GSI). The S-RNase GSI system was one of the first SI mechanisms to be biochemically characterized, and likely represents the ancestral Eudicot condition as evidenced by its functional characterization in both asterid (Solanaceae, Plantaginaceae) and rosid (Rosaceae) lineages. The S-RNase GSI mechanism employs the activity of class III RNase T2 proteins to terminate the growth of "self" pollen tubes. Here, we investigate the mechanism of Coffea GSI and specifically examine the potential for homology to S-RNase GSI by sequencing class III RNase T2 genes in populations of 14 African and Madagascan Coffea species and the closely related self-compatible species Psilanthus ebracteolatus. Phylogenetic analyses of these sequences aligned to a diverse sample of plant RNase T2 genes show that the Coffea genome contains at least three class III RNase T2 genes. Patterns of tissue-specific gene expression identify one of these RNase T2 genes as the putative Coffea S-RNase gene. We show that populations of SI Coffea are remarkably polymorphic for putative S-RNase alleles, and exhibit a persistent pattern of trans-specific polymorphism characteristic of all S-RNase genes previously isolated from GSI Eudicot lineages. We thus conclude that Coffea GSI is most likely homologous to the classic Eudicot S-RNase system, which was retained since the divergence of the Rubiaceae lineage from an ancient SI Eudicot ancestor, nearly 90 million years ago.United States National Science Foundation [0849186]; Society of Systematic Biologists; American Society of Plant Taxonomists; Duke University Graduate Schoolinfo:eu-repo/semantics/publishedVersio

Disk-Jet Connection in the Radio Galaxy 3C 120

We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 120 between 2002 and 2007 at X-ray, optical, and radio wave bands, as well as imaging with the Very Long Baseline Array (VLBA). Over the 5 yr of observation, significant dips in the X-ray light curve are followed by ejections of bright superluminal knots in the VLBA images. Consistent with this, the X-ray flux and 37 GHz flux are anti-correlated with X-ray leading the radio variations. This implies that, in this radio galaxy, the radiative state of accretion disk plus corona system, where the X-rays are produced, has a direct effect on the events in the jet, where the radio emission originates. The X-ray power spectral density of 3C 120 shows a break, with steeper slope at shorter timescale and the break timescale is commensurate with the mass of the central black hole based on observations of Seyfert galaxies and black hole X-ray binaries. These findings provide support for the paradigm that black hole X-ray binaries and active galactic nuclei are fundamentally similar systems, with characteristic time and size scales linearly proportional to the mass of the central black hole. The X-ray and optical variations are strongly correlated in 3C 120, which implies that the optical emission in this object arises from the same general region as the X-rays, i.e., in the accretion disk-corona system. We numerically model multi-wavelength light curves of 3C 120 from such a system with the optical-UV emission produced in the disk and the X-rays generated by scattering of thermal photons by hot electrons in the corona. From the comparison of the temporal properties of the model light curves to that of the observed variability, we constrain the physical size of the corona and the distances of the emitting regions from the central BH.Comment: Accepted for publication in the Astrophysical Journal. 28 pages, 21 figures, 2 table

Implementation of Client-Centered Care Coordination for HIV Prevention with Black Men Who Have Sex with Men: Activities, Personnel Costs, and Outcomes—HPTN 073

Background: Black men who have sex with men (MSM) experience disproportionate rates of HIV infection in the USA, despite being no more likely to engage in sexual risk behaviors than other MSM racial/ethnic groups. HIV pre-exposure prophylaxis (PrEP) has been shown to reduce risk of HIV acquisition; however, rates of PrEP use among Black MSM remain low. Clinical, psychosocial, and structural factors have been shown to impact PrEP use and adherence among Black MSM. Care coordination of HIV prevention services has the potential to improve PrEP use and adherence for Black MSM, as it has been shown to improve HIV-related care outcomes among people living with HIV. Methods: Client-centered care coordination (C4) is a multi-level intervention designed to address clinical, psychosocial, and structural barriers to HIV prevention services for Black MSM within HPTN 073, a PrEP demonstration project among Black MSM in three cities in the USA. The current study examined the implementation process of C4, specifically investigating the activities, cost, time, and outcomes associated with the C4 intervention. Results: On average, participants engaged in five care coordination encounters. The vast majority of care coordination activities were conducted by counselors, averaging 30 min per encounter. The cost of care coordination was relatively low with a mean cost of $8.70 per client encounter. Conclusion: Although client-centered care coordination was initially implemented in well-resourced communities with robust HIV research and service infrastructure, our findings suggest that C4 can be successfully implemented in resource constrained communities

Fragranced consumer products: effects on asthmatic Australians

Exposure to fragranced consumer products, such as air fresheners and cleaning supplies, is associated with adverse health effects such as asthma attacks, breathing difficulties, and migraine headaches. This study investigated the prevalence and types of health problems associated with exposure to fragranced products among asthmatic Australians. Nationally representative cross-sectional data were obtained in June 2016 with an online survey of adult Australians (n = 1098), of which 28.5% were medically diagnosed with asthma or an asthma-like condition. Nationally, 55.6% of asthmatics, and 23.9% of non-asthmatics, report adverse health effects after exposure to fragranced products. Specifically, 24.0% of asthmatics report an asthma attack. Moreover, 18.2% of asthmatics lost workdays or a job in the past year due to fragranced products in the workplace. Over 20% of asthmatics are unable to access public places and restrooms that use air fresheners. Exposure to fragranced products is associated with health problems, some potentially serious, in an estimated 2.2 million asthmatic adult Australians. Asthmatics were proportionately more affected than non-asthmatics (prevalence odds ratio 3.98; 95% confidence interval 3.01–5.24). Most asthmatics would prefer workplaces, healthcare facilities, and environments that are fragrance-free, which could help reduce adverse effects

A novel and well-defined benchmarking method for second generation read mapping

Background Second generation sequencing technologies yield DNA sequence data at ultra high-throughput. Common to most biological applications is a mapping of the reads to an almost identical or highly similar reference genome. The assessment of the quality of read mapping results is not straightforward and has not been formalized so far. Hence, it has not been easy to compare different read mapping approaches in a unified way and to determine which program is the best for what task. Results We present a new benchmark method, called Rabema (Read Alignment BEnchMArk), for read mappers. It consists of a strict definition of the read mapping problem and of tools to evaluate the result of arbitrary read mappers supporting the SAM output format. Conclusions We show the usefulness of the benchmark program by performing a comparison of popular read mappers. The tools supporting the benchmark are licensed under the GPL and available from http://www.seqan.de/projects/rabema.html