200 research outputs found
Isotopic studies of selenium in environmental samples.
Selenium has aroused much interest in the last decade. It is an essential trace element for man and animals and has been found to be the cofactor in two enzyme systems. The first, glutathionine peroxidase, acts as an anti-oxidant by destroying peroxides which attack cellular membranes. The second, iodothyronine 5'-deiodinase, converts thyroxine to triiodothyronine with the release of iodine. Selenium is obtained in the diet from plant and animal products and the amount present is dependent largely on the Se content and the chemical species present in local soils. Soils low in Se can lead to deficiency problems to the grazing ruminants, and have necessitated the use of Se fertilisers or direct Se injection into the livestock. The disposal of sewage sludge onto agricultural land will increase as new EC legislation comes into force in 1998. This may alleviate Se deficiency in soils or result in toxicity problems. The aims of this project were firstly to develop and validate a method to accurately measure SE in plants, soils and sewage sludges, examine which soil fractions Se was associated with and finally to study the uptake of Se by plants grown on sewage sludge amended soils. The Se concentration in samples was determined using isotope dilution - mass spectrometry by gas chromatography - mass spectrometry (GC-MS). This was the first application of the determination of Se in environmental samples and the use of a benchtop GC-MS for those analyses. Samples were spiked with 76-Se isotope solution. Plants were digested using nitric acid and hydrogen peroxide initially on a heating block and latterly by microwave oven digestion techniques. Soils and sewage sludges were digested using nitric acid and hydrofluoric acid. Selenium in the digests was reduced to Se(IV) and derivatised to 5'-nitropiazselenol. Validation of the methodology was achieved by the use of certified reference materials which gave results within the certified range with a low standard deviation. The Se content of four different freely drained acid Scottish soils under grasslands was in the range 0.5-0.8 mg-1 air dried soil and three sewage sludge samples contained between 1.1 and 3.5 mg g-1 dry matter. The ability of the digestion techniques to release organically bound Se as selenomethionine and selenocysteine was found to be around 100% efficient and the use of a microwave oven increased the number of samples which could be processed. A sequential extraction procedure was used to determine the soil fractions with which Se was associated. The four soils and the sewage sludge examined were all found to have less than 5% of the total Se available for plant uptake. The uptake of Se by plants grown in soils to which Se had been added as sodium selenate or sodium selenate was studied using both stable and radio isotopes of Se. Results obtained showed that the uptake of Se by plants grown in soils treated with selenite could be related to the soil characteristics, with ferric oxide levels, clay levels and organic matter content being the important factors. The uptake of Se by plants in the soils treated with selenate were less obviously related to soil properties but pH and P levels both appear to be important factors. Good reproducibility was obtained in all cases. Plants grown on sewage sludge amended soils were not found to contain measurable amounts of Se
What a difference a year makes:comparing relationships between stressful life events, mood and life satisfaction among older adults, and their working-age counterparts
Objectives: Stressful life events (SLEs) have been linked to depression, anxiety, and reduced life satisfaction. The inoculation hypothesis of aging suggests older adults may be less vulnerable to poor psychological outcomes following SLEs than working-age adults. The current study compared relationships between SLEs, mood and life satisfaction among older adults (65+), and adults aged 50â64, and investigated whether group identification and loneliness moderate these relationships.
Method: A community-based sample of 121 Scottish participants responded to measures of SLEs (modified Social Readjustment Rating Scale), symptoms of depression and anxiety (Hospital Anxiety and Depression Scale), life satisfaction (Life Satisfaction Index A), group identification (Group Identification Scale), and loneliness (UCLA Loneliness Scale).
Results: In the 50â64 age group, the number of SLEs was significantly associated with greater symptoms of depression and anxiety, and reduced life satisfaction. Group identification and loneliness did not moderate these relationships. There were no significant relationships in the older adult group.
Conclusion: The finding of relationships in working-age, but not older adults, supports the inoculation hypothesis of aging. Further research to better understand changes across the lifespan, and inter-relationships with related variables, would be valuable from both theoretical and clinical perspectives
Towards an increased understanding of reminiscence therapy for people with dementia: A narrative analysis
Aim Reminiscence therapy is a popular therapeutic intervention for people with dementia. This review set out to provide a better understanding of reminiscence therapy through a deeper analysis of its contents and delivery. Method This review examined 22 studies from the most recent Cochrane review (Woods, B., OâPhilbin, L., Farrell, E. M., Spector, A. E., & Orrell, M. (2018). Reminiscence therapy for dementia. Cochrane Database of Systematic Reviews, 3, Article 001120) and addressed the following research questions: (1) What are the components of reminiscence therapy? (2) Who delivers reminiscence therapy? (3) How is reminiscence therapy delivered? (4) Is reminiscence therapy underpinned by a theoretical framework? (5) Is reminiscence therapy delivered according to a programme/model? (6) Are there commonalities in the reminiscence therapy components utilised? Multiple and layered narrative analyses were completed. Findings Thirteen reminiscence therapy components were identified. âMemory triggersâ and âthemesâ were identified as the most common but were found not to be consistently beneficial. Reminiscence therapy was typically delivered in a care setting using a group approach; however, there was no consistency in session composition, intervention duration, as well as the training and supervision provided to facilitators. Operationalisation of theory within reminiscence therapy was not identified. Reminiscence therapy was not consistently delivered according to a programme/model. Lastly, as a result of a small number of studies, the components âlife stagesâ, âactivitiesâ and âfamily-only sessionsâ, showed beneficial promise. In summary, this review highlights that reminiscence therapy needs more consistency in content and delivery, in addition to a clear theoretical framework
Combining STEM and LOTE education: the SI Cube
The use of metric and SI units is an integral part of the mathematics and science curricula. Too often, students rote-learn lists of units, names, prefixes, and conversion factors. This memorisation is contrary to models of learning, in which the learning activity should be customised to the way that individual students learn most effectively, or at least, learn more effectively. The use of physical objects, which can be manipulated, helps students to relate to the concepts being learned by being able to visualise a concrete example of the concept as well as engaging the tactile sense (Dunn & Dunn, 1993; Dunn & Griggs, 2000; Gardner, 1993; Kolb, 1984; Markova & Powell, 1992; McInerney & McInerney, 1998).
A 10 cm Ă 10 cm Ă 10 cm âSI Cubeâ, which helps students learn SI units, has previously been developed (Lim, 2011). Students can physically handle and manipulate the SI Cube, which also helps them to have a better appreciation of volume.
A LOTE (language other than English) version of the SI cube is presented. This has been used to teach Japanese in a science and mathematics context to primary and secondary school students
Patient, carer and professional perspectives on barriers and facilitators to quality care in advanced heart failure
BACKGROUND: Those with advanced heart failure (HF) experience high levels of morbidity and mortality, similar to common cancers. However, there remains evidence of inequity of access to palliative care services compared to people with cancer. This study examines patient, carer, and professional perspectives on current management of advanced HF and barriers and facilitators to improved care.METHODS: Qualitative study involving semi-structured interviews and focus groups with advanced HF patients (n = 30), carers (n = 20), and professionals (n = 65). Data analysed using Normalisation Process Theory (NPT) as the underpinning conceptual framework.FINDINGS: Uncertainty is ubiquitous in accounts from advanced HF patients and their caregivers. This uncertainty relates to understanding of the implications of their diagnosis, appropriate treatments, and when and how to seek effective help. Health professionals agree this is a major problem but feel they lack knowledge, opportunities, or adequate support to improve the situation. Fragmented care with lack of coordination and poor communication makes life difficult. Poor understanding of the condition extends to the wider circle of carers and means that requests for help may not be perceived as legitimate, and those with advanced HF are not prioritised for social and financial supports. Patient and caregiver accounts of emergency care are uniformly poor. Managing polypharmacy and enduring concomitant side effects is a major burden, and the potential for rationalisation exists. This study has potential limitations because it was undertaken within a single geographical location within the United Kingdom.CONCLUSIONS: Little progress is being made to improve care experiences for those with advanced HF. Even in the terminal stages, patients and caregivers are heavily and unnecessarily burdened by health care services that are poorly coordinated and offer fragmented care. There is evidence that these poor experiences could be improved to a large extent by simple organisational rather than complex clinical mechanisms
Breaking the silence on abortion: the role of adult community abortion education in fostering resistance to norms
Meanings of abortion in society are constructed within sociohistorical and gendered spaces and manifested through myriad discourses that impact on the perception and treatment of the issue in that society. In societies with powerful oppressive anti-abortion norms, such as Northern Ireland, little is known as to how these norms are resisted by the adult population. This study uses a Foucauldian feminist approach to show how resistance to religious and patriarchal norms can be fostered through adult community abortion education. This resistance is multi-faceted and bolstered by a lived experience discourse, which does not necessarily involve eschewing religious notions held within society
Effects of dietary fat manipulation on cognition in mice and rats:protocol for a systematic review and meta-analysis
INTRODUCTION AND OBJECTIVE: The Western diet that comprises high levels of long-chain saturated fats and sugar is associated not only with metabolic disorders such as obesity and type 2 diabetes but also has been recently linked to brain changes and cognitive dysfunction. However, in animal studies, reported effects are variable, and the mechanisms underlying these effects are unclear. In the proposed review, we aim to summarise the diverse evidence of the effects of so-called âhigh-fatâ and ketogenic diets on behavioural measures of cognition in postweaning mice and rats, relative to animals on standard diets and to determine potential underlying mechanisms of high-fat diet-induced effects. SEARCH STRATEGY: A comprehensive search strategy was designed to retrieve studies reporting use of a high-fat or ketogenic diet in postweaning mice and rats that included cognitive assessments. Three databases (Medline, SCOPUS and Web of Science) were searched and 4487 unique references were retrieved. SCREENING AND ANNOTATION: Studies were screened for inclusion by two independent reviewers, with 330 studies retained for analysis. Characteristics of disease model choice, experimental design, intervention use and outcome assessment are to be extracted using the Systematic Review Facility (http://syrf.org.uk/) tool. Studies will be assessed for study quality and risk of bias and confidence of mechanistic involvement. DATA MANAGEMENT AND REPORTING: For cognitive outcomes, effect sizes will be calculated using normalised mean difference and summarised using a random effects model. The contribution of potential sources of heterogeneity to the observed effects of diet on cognition will be assessed using multivariable meta-regression, with partitioning of heterogeneity as a sensitivity analysis. A preliminary version of this protocol was published on 9 April 2019 on the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies website (http://www.dcn.ed.ac.uk/camarades/research.html%23protocols). ETHICS AND DISSEMINATION: No ethical approval is required as there are no subjects in the proposed study
Designing, conducting, and reporting reproducible animal experiments
In biomedicine and many other fields, there are growing concerns around the reproducibility of research findings, with many researchers being unable to replicate their own or others' results. This raises important questions as to the validity and usefulness of much published research. In this review, we aim to engage researchers in the issue of research reproducibility and equip them with the necessary tools to increase the reproducibility of their research. We first highlight the causes and potential impact of non-reproducible research and emphasise the benefits of working reproducibly for the researcher and broader research community. We address specific targets for improvement and steps that individual researchers can take to increase the reproducibility of their work. We next provide recommendations for improving the design and conduct of experiments, focusing on in vivo animal experiments. We describe common sources of poor internal validity of experiments and offer practical guidance for limiting these potential sources of bias at different experimental stages, as well as discussing other important considerations during experimental design. We provide a list of key resources available to researchers to improve experimental design, conduct, and reporting. We then discuss the importance of open research practices such as study preregistration and the use of preprints and describe recommendations around data management and sharing. Our review emphasises the importance of reproducible work and aims to empower every individual researcher to contribute to the reproducibility of research in their field.</p
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