1,394 research outputs found

    Investigating the Dark Sector: Attempting to Resolve the Hubble Tension with a Modified Model of the Universe

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    The standard model of Big Bang cosmology is the ΛCDM model, which incorporates cold dark matter and dark energy, two mysterious components of what is known as the “dark sector” of the universe, or sector not directly observable with light. Observations of primordial light in the universe allow precision tests of cosmological models, including the expansion rate of the universe, also known as the Hubble constant. Values of the Hubble constant determined using observations of primordial light and the ΛCDM model are in disagreement with the value determined from local observables, such as the recession velocities of galaxies observable with satellites. This tension may indicate a need to move beyond standard ΛCDM. During my International Research Opportunities Program (IROP) research at the Indian Institute of Astrophysics in Bangalore, India, I studied a possible extension of the ΛCDM model in which cold dark matter decays into dark radiation. In this project I investigated the effects of decaying dark matter on cosmological observables such as the Hubble constant. My results show that the decaying dark matter model may help alleviate tension between the indirect and direct 0determinations of the Hubble constant

    The meaning and experience of well-being in dementia for psychiatrists involved in diagnostic disclosure: a qualitative study

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    Literature indicates that people's experiences of receiving a diagnosis of dementia can have a lasting impact on well-being. Psychiatrists frequently lead in communicating a diagnosis but little is known about the factors that could contribute to potential disparities between actual and best practice with regard to diagnostic disclosure. A clearer understanding of psychiatrists’ subjective experiences of disclosure is therefore needed to improve adherence to best practice guidelines and ensure that diagnostic disclosure facilitates living well with dementia. This study utilized qualitative methodology. Semi-structured interviews conducted with 11 psychiatrists were analyzed using Interpretive Phenomenological Analysis (IPA). Three superordinate and nine subordinate themes emerged from the data analysis. These included the following: (i) “The levels of well-being” (Continuing with life, Keeping a sense of who they are, Acceptance of the self), (ii) “Living well is a process” (Disclosure can set the scene for well-being, Positive but realistic messages, Whose role it is to support well-being?), and (iii) Ideal care versus real care (Supporting well-being is not prioritized, There isn't time, The fragmentation of care). Findings indicate that psychiatrists frame well-being in dementia as a multi-faceted biopsychosocial construct but that certain nihilistic attitudes may affect how well-being is integrated into diagnostic communication. Such attitudes were linked with the perceived threat of dementia and limitations of post-diagnostic care. Behaviors used to manage the negative affect associated with ethical and clinical tensions triggered by attempts to facilitate well-being at the point of diagnosis, and their impact on adherence to best practice disclosure, are discussed

    Living positively with dementia: a systematic review and synthesis of the qualitative literature

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    Objective: Little is known about how and to what extent people with dementia live positively with their condition. This study aimed to review and carry out a synthesis of qualitative studies where accounts of the subjective experiences of people with dementia contained evidence of positive states, experiences or attributes. Methods: A meta-synthesis was undertaken to generate an integrated and interpretive account of the ability of people with dementia to have positive experiences. A methodological quality assessment was undertaken to maximize the reliability and validity of this synthesis and to contextualize the findings with regard to methodological constraints and epistemological concepts. Findings: Twenty-seven papers were included. Three super-ordinate themes relating to positive experiences and attributes were identified, each with varying and complementing sub-themes. The first super-ordinate theme related to the experience of engaging with life in ageing rather than explicitly to living with dementia. The second theme related to engaging with dementia itself and comprised the strengths that people can utilize in facing and fighting the condition. The third theme captured how people with dementia might transcend the condition and seek ways to maintain identity and even achieve personal growth. Conclusions: This review provides a first step towards understanding what conceptual domains might be important in defining positive outcomes for people who live with dementia. Highlighting the potential for people to have positive experiences in spite of or even because of their dementia has important implications for de-stigmatizing dementia and will enhance person-centred approaches to care

    Ethical dilemmas experienced by Australian public practice occupational therapists

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    Occupational therapists working within Australia’s dynamic and complex publicly-funded health sector may experience ethical dilemmas as they fulfill their professional responsibilities, compromising client care, straining collegial relationships and negatively affecting their personal well-being. This thesis describes and explores the nature of the ethical dilemmas experienced by public practice occupational therapists. Section One: LITERATURE REVIEW The literature review comprises two parts. First a background to ethics in health care is outlined, where the Person-Environment-Occupation Model is presented as a way of evaluating the ethical dilemmas experienced by occupational therapists. This is followed by a review of literature exploring the ethical dilemmas experienced by health professionals including occupational therapists, speech pathologists, physiotherapists, social workers, rehabilitation counsellors and nursing and medical professionals. However, no literature was identified exploring the nature of ethical dilemmas experienced by public practice occupational therapists, providing an opportunity for further research. Section Two: JOURNAL MANUSCRIPT The journal manuscript outlines a qualitative, descriptive study exploring the ethical dilemmas experienced by five public practice occupational therapists. Findings indicate that public practice occupational therapists experience an array of ethical dilemmas which reflect the complexities of working within Australia’s publicly-funded health care context. Ethical dilemmas reported by public practice occupational therapists are encompassed by five themes: defining boundaries in professional relationships, fair access to quality services, professional status, life choices and the complex client at the heart of the dilemma. Person, environment and occupation factors were all found to contribute to the ethical dilemmas experienced by participants

    Ethical dilemmas experienced by Australian public practice occupational therapists

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    Occupational therapists working within Australia’s dynamic and complex publicly-funded health sector may experience ethical dilemmas as they fulfill their professional responsibilities, compromising client care, straining collegial relationships and negatively affecting their personal well-being. This thesis describes and explores the nature of the ethical dilemmas experienced by public practice occupational therapists. Section One: LITERATURE REVIEW The literature review comprises two parts. First a background to ethics in health care is outlined, where the Person-Environment-Occupation Model is presented as a way of evaluating the ethical dilemmas experienced by occupational therapists. This is followed by a review of literature exploring the ethical dilemmas experienced by health professionals including occupational therapists, speech pathologists, physiotherapists, social workers, rehabilitation counsellors and nursing and medical professionals. However, no literature was identified exploring the nature of ethical dilemmas experienced by public practice occupational therapists, providing an opportunity for further research. Section Two: JOURNAL MANUSCRIPT The journal manuscript outlines a qualitative, descriptive study exploring the ethical dilemmas experienced by five public practice occupational therapists. Findings indicate that public practice occupational therapists experience an array of ethical dilemmas which reflect the complexities of working within Australia’s publicly-funded health care context. Ethical dilemmas reported by public practice occupational therapists are encompassed by five themes: defining boundaries in professional relationships, fair access to quality services, professional status, life choices and the complex client at the heart of the dilemma. Person, environment and occupation factors were all found to contribute to the ethical dilemmas experienced by participants

    Through the eyes of others - The social experiences of people with dementia: A systematic literature review and synthesis

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    Psychosocial models suggest that the lived experience of dementia is affected by interpersonal factors such as the ways in which others view, talk about, and behave toward the person with dementia. This review aimed to illuminate how informal, everyday interpersonal relationships are experienced by people with dementia within their social contexts. A systematic review of qualitative literature published between 1989 and May 2016 was conducted, utilizing the electronic databases PsycINFO, MEDLINE, and CINAHL-Complete. This was followed by a critical interpretative synthesis to understand how people with dementia perceive the attitudes, views, and reactions of other people toward them, and the subjective impact that these have. Four major themes were derived from the findings of the 23 included studies: being treated as an “other” rather than “one of us”; being treated as “lesser” rather than a full, valued member of society; the impact of others’ responses; and strategies to manage the responses of others. Thus, people with dementia can feel outcast and relegated, or indeed feel included and valued by others. These experiences impact upon emotional and psychological well-being, and are actively interpreted and managed by people with dementia. Experiences such as loss and diminishing identity have previously been understood as a direct result of dementia, with little consideration of interpersonal influences. This review notes that people with dementia actively engage with others, whose responses can foster or undermine social well-being. This dynamic relational aspect may contribute to emerging understandings of social health in dementia

    How do teaching assistants view their role in managing behaviour and cultivate their learning and understanding in relation to managing behaviour?

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    This paper will consider how teaching assistants’ (TAs’) roles are changing from the historical ‘mum’s army’ (Bach Kessler & Heron, 2006) of paint-pot washers, as some considered it pre-national curriculum, to the developing conception of the TA as a ‘paraprofessional’. Contemporary issues arising from the loosely defined current expectations of TAs’ wider pedagogical role will also be discussed. Consideration will be given to how and why managing behaviour has become an expectation and a necessity for TAs in their current deployment in schools, and why learning about managing behaviour differs for TAs and teachers. Additionally, the paper will reflect on the specific challenges facing TAs in managing behaviour. How TAs learn from each other in communities of practice, as well as from teachers and senior leaders, will be explored. Furthermore, how behaviour policies and policy implementation generally can influence TAs’ opportunities to promote their own learning will be reviewed

    The effects of a UK review of breast cancer screening on uptake : an observational before/after study

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    Objectives: To measure whether uptake of breast cancer screening was affected by the publication of the Marmot Review and associated press coverage. Setting: Eight NHS breast screening centres in the West Midlands of the UK. Methods: Uptake of breast cancer screening invitations was compared in the week before and after the Marmot review publication. All 12,023 women invited for screening between 23 October 2012 and 5 November 2012 were included. A mixed effects model of the predictors of screening uptake (on date invited, or within 21 days) was created. Predictors considered for inclusion were whether the allocated screening appointment was before or after publication of the review, population factors (age, index of multiple deprivation income domain by quintile, previous attendance), and interaction terms. Results: Uptake decreased after publication of the review from 65% to 62% (OR = 0.87 95%CI = 0.80–0.94), but a similar decrease was seen for the same dates on the previous year (OR = 0.85 95%CI = 0.78–0.93). Odds of attending screening were lower for women in the most deprived (uptake = 49%, OR = 0.54, 95%CI = 0.46–0.62) in comparison with the least deprived quintile (uptake = 71%). Odds of attendance also increased if the woman had ever previously attended (OR 3.9 95% CI 3.5–4.4), and decreased with each year of increasing age (OR 0.96 95% CI 0.96–0.97). There were no interactions between any of the other predictors and whether the appointment was before or after publication of the Marmot review. Conclusion: No change in uptake of breast cancer screening above normal seasonal variation was detected after publication of the Marmot review

    An investigation into silver nanoparticles removal from water during sand filtration and activated carbon adsorption

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    Wastewater treatment plants (WwTP) act as the principle buffer between anthropogenic sources of Silver Nanoparticles (AgNPs) and environmental targets. AgNPs, given their effective anti-microbial properties, have the potential to negatively impact WwTP processes and organisms within the natural environment. A clear understanding of the fate and transport of AgNPs as they pass through WwTPs is crucial in evaluating AgNPs impacts for WwTP process, the natural environment and in the development of a comprehensive environmental risk assessment for AgNPs. The main aim of this thesis was to carry out an analysis on the fate, transport and transformation of AgNPs through WwTP relevant filtration medias in order to understand more about the toxicological implications for both WwTP processes and receiving environments. AgNPs were synthesised in-house, via an in-situ reduction method, which produced a homogeneous dispersion of nanoparticles of average particle diameter 9.98nm, with a standard deviation of 3.11nm. Column studies and adsorption isotherm experiments were conducted to investigate the fate and transport of silver nitrate, AgNPs and bulk silver across media beds of quartz sand and granulated activated carbon (GAC), both chosen for their relevance in wastewater treatment protocols. TEM imaging and EDS analysis was employed to characterise the AgNPs physically and elementally within the column influents and effluents. An original contribution made to the existing knowledge on AgNPs is that in contrast to bulk silver and silver nitrate, uncoated AgNPs were observed to be highly mobile through the quartz sand media. This high mobility was in contrast with the prior expectation that van der Waals forces of attraction between the positively charged AgNPs and the negative charge of the silica surfaces within the sand bed would lead to some measure of retention within the column matrix. The resulting high mobility of the AgNPs was attributed to particle surface contamination of boride ions originating from the reduction agent used during the synthesis process. This highlights (and reinforces) the importance of better understanding on the implications of the various methods of synthesis and use of capping agents for AgNPs characteristics and the impact this has on fate and transport. AgNPs were also noted to have been significantly altered after their passage through the quartz sand media, with up to 83% of the sample increasing in size, from 9.98nm to an average of 18.26nm and a maximum of 144nm. Particle size measurements were made using the measuring tool available in the GNU Image Manipulation Program (GIMP). This size increase was attributed to the formation of nano-alloy clusters with residual gold and iron compounds, naturally present within the sand bed. In the case of silver-gold alloy clusters, this is expected to exhibit positive implications for future environmental fates of the resulting AgNPs, where the presence of gold in alloy clusters has been observed to significantly deactivate AgNPs silver ion release. In contrast to the sand, it was observed that the GAC was an effective absorber of AgNPs. However, this was observed to be a size dependant relationship, where the GAC was not observed to be effective for adsorption of bulk silver at particle sizes of 300 – 800nm. In this thesis, in addition to the experimental work, a novel, low complexity technique was developed for the detection and quantification of AgNPs in laboratory aqueous solutions. This protocol utilises a laboratory bench top photometer and gave AgNPs concentration results that reliably and accurately reflected that of ICP-MS and ICP-OES results within a detection range of 0.01 and 20mg/L; where the correlation coefficient between the instrument absorbance response and ICP-MS/OES concentration (at 450nm) was R2 0.994.College of Engineering, Mathematics and Physical Sciences, University of Exeter
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