1,661 research outputs found
Subjective responses to display bezel characteristics
High quality flat panel computer displays (FPDs) with high resolution screens are now commonplace, and black, grey, white, beige and silver surrounds (âbezelsâ), matt or glossy, are in widespread use. It has been suggested that bezels with high reflectance, or with a high gloss, could cause eyestrain, and we have investigated this issue. Twenty office workers (unaware of the study purpose) used six different FPDs, for a week each, at their own desk. These displays were identical apart from the bezel colour (black, white or silver) and shininess (matt or glossy). Participants completed questionnaires about their visual comfort at the end of each week, and were fully debriefed in lunch-time focus groups at the end of the study. For the white and the silver bezels, the glossiness of the bezel was not an issue of concern. The participants were significantly less content with the glossy black surround than with the matt black surround, and in general the glossy black bezel was the least-liked of all those used. With the possible exception of this surround, there was no evidence of significantly increased visual discomfort, indicative of eyestrain, as a result of high or low bezel reflectance, or of high glossiness
Surface abundances of ON stars
Massive stars burn hydrogen through the CNO cycle during most of their
evolution. When mixing is efficient, or when mass transfer in binary systems
happens, chemically processed material is observed at the surface of O and B
stars. ON stars show stronger lines of nitrogen than morphologically normal
counterparts. Whether this corresponds to the presence of material processed
through the CNO cycle or not is not known. Our goal is to answer this question.
We perform a spectroscopic analysis of a sample of ON stars with atmosphere
models. We determine the fundamental parameters as well as the He, C, N, and O
surface abundances. We also measure the projected rotational velocities. We
compare the properties of the ON stars to those of normal O stars. We show that
ON stars are usually helium-rich. Their CNO surface abundances are fully
consistent with predictions of nucleosynthesis. ON stars are more chemically
evolved and rotate - on average - faster than normal O stars. Evolutionary
models including rotation cannot account for the extreme enrichment observed
among ON main sequence stars. Some ON stars are members of binary systems, but
others are single stars as indicated by stable radial velocities. Hence, mass
transfer is not a simple explanation for the observed chemical properties. We
conclude that ON stars show extreme chemical enrichment at their surface,
consistent with nucleosynthesis through the CNO cycle. Its origin is not clear
at present.Comment: 18 pages, 10 figures (+ appendix). A&A accepte
Banning the bulb: institutional evolution and the phased ban of incandescent lighting in Germany
Much academic attention has been directed at analysing energy efficiency investments through the lens of âbehavioural failureâ. These studies have challenged the neoclassical framing of regulation which emphasises the efficiency benefits of price based policy, underpinned by the notion of rational individual self-mastery. The increasing use of a regulatory ban on electric lamps in many countries is one of the most recent and high profile flash points in this dialectic of âfreedom-versus-the-stateâ in the public policy discourse. This paper interrogates this debate through a study of electric lamp diffusion in Germany. It is argued that neoclassical theory and equilibrium analysis is inadequate as a tool for policy analysis as it takes the formation of market institutions, such as existing regulations, for granted. Further still, it may be prone to encourage idealistic debates around such grand narratives which may in practice simply serve those who benefit most from the status quo. Instead we argue for an evolutionary approach which we suggest offers a more pragmatic framing tool which focuses on the formation of market institutions in light of shifting social norms and political goalsâin our case, progress towards energy efficiency and environmental goals
Diencephalic syndrome in child with NF-1 and hypothalamic tumour
We describe a 20 month old boy with neuro-fibromatosis type 1 (NF-1) who presented with diencephalic syndrome due to a large hypothalamic tumour and developed massive necrosis after chemotherapy associated with severe encephalopathy.
We report this case because of rapid progression of presenting symptoms, the rare association with diencephalic syndrome in NF-1, chemotherapy induction of âtumour lysisâ associated with encephalopathy, reduced toxicity and sustained improvement with vinblastine, the therapeutic benefit of tumour drainage signs of resolution of diencephalic syndrome and then restoration of visual movements and function associated with developmental recovery. The presentation of tumour in this case highlights the importance for parents and doctor to known and recognize the precocious symptoms, and justifies sharing these features as an indicator with parents and GPâs to justify early / urgent specialist review, particularly in the first two years of life. Early recognition could offer a reduced risk of brain injury
Access to and perceived unmet need for mental health services and support in a community sample of UK adolescents with and without experience of childhood adversity
Aims. Children and adolescents with a history of adverse childhood experiences (ACEs) are more likely than their peers to develop mental health difficulties, but not enough is known about their help-seeking behaviours and preferences. We aimed to determine whether and how ACEs are associated with access to and perceived unmet need for mental health services and support amongst secondary school students.
Methods: We used multi-level logistic regression with data from the 2020 OxWell Student Survey to assess whether ACEs were associated with (1) prior access to mental health support and (2) perceived unmet need for mental health services in a community sample of English secondary school students. We assessed ACEs as a cumulative score from the Center
for Youth Wellness Adverse Childhood Experiences Questionnaire: Teen Self-Report version and accounted for current mental health difficulties as measured by the 25-item Revised Childrenâs Anxiety and Depression Scale (RCADS).
Results: Our analysis included 2018 students across 64 schools, of whom 29.9% (598/2002) reported prior access to mental health support and 34.1% (469/1377) reported a perceived unmet need for services. In the unadjusted models, the cumulative ACE score was significantly positively associated with both prior access to mental health support (odds ratio (OR)=1.36; 95% confidence interval (CI) 1.29â1.43) and perceived unmet need for mental health services (OR=1.47; 95% CI 1.37â1.59), meaning that students who had experienced adversity had a greater chance of having previously accessed support as well as perceiving an unmet need for services. After adjusting for mental health difficulties and other sociodemographic variables, cumulative ACE scores were positively associated with prior access (adjusted OR (aOR)=1.25; 95% CI 1.17â1.34 with a significant interaction between RCADS and ACE scores, aOR=0.88; 95% CI 0.84â0.93) as well as perceived unmet need (aOR=1.32; 95% CI
1.21â1.43 with a significant interaction between RCADS and ACE scores, aOR=0.85; 95% CI 0.78â0.91).
Conclusions: Although it is encouraging that adolescents with experience of adversity are more likely than their peers with similar levels of depression and anxiety symptoms to have accessed mental health support, there remains a concern that those who have not accessed support are more likely to perceive an as-yet unmet need for it. Mental health support must be available, accessible, and acceptable to all who need it, especially for those groups that traditionally have not accessed services, including the more marginalised and vulnerable populations
The relative timing of mutations in a breast cancer genome.
Many tumors have highly rearranged genomes, but a major unknown is the relative importance and timing of genome rearrangements compared to sequence-level mutation. Chromosome instability might arise early, be a late event contributing little to cancer development, or happen as a single catastrophic event. Another unknown is which of the point mutations and rearrangements are selected. To address these questions we show, using the breast cancer cell line HCC1187 as a model, that we can reconstruct the likely history of a breast cancer genome. We assembled probably the most complete map to date of a cancer genome, by combining molecular cytogenetic analysis with sequence data. In particular, we assigned most sequence-level mutations to individual chromosomes by sequencing of flow sorted chromosomes. The parent of origin of each chromosome was assigned from SNP arrays. We were then able to classify most of the mutations as earlier or later according to whether they occurred before or after a landmark event in the evolution of the genome, endoreduplication (duplication of its entire genome). Genome rearrangements and sequence-level mutations were fairly evenly divided earlier and later, suggesting that genetic instability was relatively constant throughout the life of this tumor, and chromosome instability was not a late event. Mutations that caused chromosome instability would be in the earlier set. Strikingly, the great majority of inactivating mutations and in-frame gene fusions happened earlier. The non-random timing of some of the mutations may be evidence that they were selected
Heterogeneous natural history of Addisonâs disease: mineralocorticoid deficiency may predominate
Autoimmune Addisonâs disease (AAD) is defined as primary adrenal insufficiency due to immune-mediated destruction of the adrenal cortex. This destruction of steroid-producing cells has historically been thought of as an irreversible process, with linear progression from an ACTH-driven compensated phase to overt adrenal insufficie ncy requiring lifelong glucocorticoid replacement. However, a growing body of evidence suggests that this process may be more heterogeneous than previously thought, with potential for complete or partial recovery of glucocorticoid secretion. Although patients with persistent mineralocorticoid deficiency despite preserved or recovered glucocorticoid function are anecdotally mentioned, few well-documented cases have been reported to date. We present three patients in the United Kingdom who further challenge the long-standing hypothesis that AAD is a progressive, irreversible disease process. We describe one patient with a 4-year history of mineralocorticoid-only Addisonâs disease, a patient with spontaneous recovery of adrenal function and one patient with clinical features of adrenal insufficiency despite significant residual cortisol function. All three patients show varying degrees of mineralocorticoid deficiency, suggesting that recovery of zona fasciculata function in the adrenal cortex may occur independently to that of the zona glomerulosa. We outline the current evidence for heterogeneity in the natural history of AAD and discuss possible mechanisms for the recovery of adrenal function
- âŠ