1,710 research outputs found
An optical spectrophotometric survey of abundances in Magellanic Cloud Planetary Nebulae
Optical spectroscopic data for 71 Planetary Nebulae (PN) in the Large and Small Magellanic Clouds have been analysed. The line fluxes have been used to determine nebular temperatures, densities, and the abundances of He, N, O, Ne, and Ar, relative to H. In our sample there are 12 nebulae with N/O≽0.5, resembling Peimbert's Type I PN; six low-excitation (LE) objects [1≼I(5007)/I(Hβ)≼4]; and four very-low-excitation (VLE) nebulae [I(Hβ)>I(5007)], similar to the Galactic VLE class. Mean abundances have been calculated for the nebulae not in these special groups. After correction for collisional excitation contributions to the nebular He I lines, PN in the SMC and LMC yield mass fractions of Y=0.249±0.025 and Y=0.258±0.015, respectively. Compared with PN in our own Galaxy, the abundances of Ne and Ar, which are the elements in our sample least affected by nucleosynthesis, are lower by 0.6 and 0.35 dex for the SMC and LMC respectively. The oxygen and neon abundances in the Magellanic Cloud PN are the same as those previously found for H II regions in the LMC and SMC, but the nitrogen in PN is enhanced by 0.9 and 1.0 dex in each galaxy, respectively. This is found to be consistent with the processing of all of the original carbon to nitrogen by the CN cycle, operating in the progenitor stars at the time of the first dredge-up. This process seems to have operated much more efficiently in the metal-poor Magellanic Clouds than in the Milky Way, in agreement with theoretical predictions. Five Wolf–Rayet central stars are detected in the sample (two SMC, three LMC). The frequency of occurrence of these helium-rich central stars in low- and medium-excitation PN (15 per cent) is very similar to that of helium-rich white dwarfs in the solar neighbourhood, suggesting that events at the end of the AGB phase may be reponsible for the observed fractions of helium- and hydrogen-rich white dwarf stars
Fast and flexible selection with a single switch
Selection methods that require only a single-switch input, such as a button
click or blink, are potentially useful for individuals with motor impairments,
mobile technology users, and individuals wishing to transmit information
securely. We present a single-switch selection method, "Nomon," that is general
and efficient. Existing single-switch selection methods require selectable
options to be arranged in ways that limit potential applications. By contrast,
traditional operating systems, web browsers, and free-form applications (such
as drawing) place options at arbitrary points on the screen. Nomon, however,
has the flexibility to select any point on a screen. Nomon adapts automatically
to an individual's clicking ability; it allows a person who clicks precisely to
make a selection quickly and allows a person who clicks imprecisely more time
to make a selection without error. Nomon reaps gains in information rate by
allowing the specification of beliefs (priors) about option selection
probabilities and by avoiding tree-based selection schemes in favor of direct
(posterior) inference. We have developed both a Nomon-based writing application
and a drawing application. To evaluate Nomon's performance, we compared the
writing application with a popular existing method for single-switch writing
(row-column scanning). Novice users wrote 35% faster with the Nomon interface
than with the scanning interface. An experienced user (author TB, with > 10
hours practice) wrote at speeds of 9.3 words per minute with Nomon, using 1.2
clicks per character and making no errors in the final text.Comment: 14 pages, 5 figures, 1 table, presented at NIPS 2009 Mini-symposi
Characterization of Novel Paternal ncRNAs at the Plagl1 Locus, Including Hymai, Predicted to Interact with Regulators of Active Chromatin
Genomic imprinting is a complex epigenetic mechanism of transcriptional control that utilizes DNA methylation and histone modifications to bring about parent-of-origin specific monoallelic expression in mammals. Genes subject to imprinting are often organised in clusters associated with large non-coding RNAs (ncRNAs), some of which have cis-regulatory functions. Here we have undertaken a detailed allelic expression analysis of an imprinted domain on mouse proximal chromosome 10 comprising the paternally expressed Plagl1 gene. We identified three novel Plagl1 transcripts, only one of which contains protein-coding exons. In addition, we characterised two unspliced ncRNAs, Hymai, the mouse orthologue of HYMAI, and Plagl1it (Plagl1 intronic transcript), a transcript located in intron 5 of Plagl1. Imprinted expression of these novel ncRNAs requires DNMT3L-mediated maternal DNA methylation, which is also indispensable for establishing the correct chromatin profile at the Plagl1 DMR. Significantly, the two ncRNAs are retained in the nucleus, consistent with a potential regulatory function at the imprinted domain. Analysis with catRAPID, a protein-ncRNA association prediction algorithm, suggests that Hymai and Plagl1it RNAs both have potentially high affinity for Trithorax chromatin regulators. The two ncRNAs could therefore help to protect the paternal allele from DNA methylation by attracting Trithorax proteins that mediate H3 lysine-4 methylation
Personalized Antihypertensive Treatment Optimization With Smartphone-Enabled Remote Precision Dosing of Amlodipine During the COVID-19 Pandemic (PERSONAL-CovidBP Trial).
BACKGROUND: The objective of the PERSONAL-CovidBP (Personalised Electronic Record Supported Optimisation When Alone for Patients With Hypertension: Pilot Study for Remote Medical Management of Hypertension During the COVID-19 Pandemic) trial was to assess the efficacy and safety of smartphone-enabled remote precision dosing of amlodipine to control blood pressure (BP) in participants with primary hypertension during the COVID-19 pandemic. METHODS AND RESULTS: This was an open-label, remote, dose titration trial using daily home self-monitoring of BP, drug dose, and side effects with linked smartphone app and telemonitoring. Participants aged ≥18 years with uncontrolled hypertension (5-7 day baseline mean ≥135 mm Hg systolic BP or ≥85 mm Hg diastolic BP) received personalized amlodipine dose titration using novel (1, 2, 3, 4, 6, 7, 8, 9 mg) and standard (5 and 10 mg) doses daily over 14 weeks. The primary outcome of the trial was mean change in systolic BP from baseline to end of treatment. A total of 205 participants were enrolled and mean BP fell from 142/87 (systolic BP/diastolic BP) to 131/81 mm Hg (a reduction of 11 (95% CI, 10-12)/7 (95% CI, 6-7) mm Hg, P<0.001). The majority of participants achieved BP control on novel doses (84%); of those participants, 35% were controlled by 1 mg daily. The majority (88%) controlled on novel doses had no peripheral edema. Adherence to BP recording and reported adherence to medication was 84% and 94%, respectively. Patient retention was 96% (196/205). Treatment was well tolerated with no withdrawals from adverse events. CONCLUSIONS: Personalized dose titration with amlodipine was safe, well tolerated, and efficacious in treating primary hypertension. The majority of participants achieved BP control on novel doses, and with personalization of dose there were no trial discontinuations due to drug intolerance. App-assisted remote clinician dose titration may better balance BP control and adverse effects and help optimize long-term care. REGISTRATION: URL: clinicaltrials.gov. Identifier: NCT04559074
Sleep disorder or simple sleep ontogeny? Tendency for morningness is associated with worse sleep quality in the elderly
Framing or Gaming? Constructing a Study to Explore the Impact of Option Presentation on Consumers
The manner in which choice is framed influences individuals’ decision-making. This research examines the impact of different decision constructs on decision-making by focusing on the more problematic decision constructs: the un-selected and pre-selected optout. The study employs eye-tracking with cued retrospective think-aloud (RTA) to combine quantitative and qualitative data. Eye-tracking will determine how long a user focuses on a decision construct before taking action. Cued RTA where the user will be shown a playback of their interaction will be used to explore their attitudes towards a decision construct and identify problematic designs. This pilot begins the second of a three phase study, which ultimately aims to develop a research model containing the theoretical constructs along with hypothesized causal associations between the constructs to reveal the impact of measures such as decision construct type, default value type and question framing have on the perceived value of the website and loyalty intentions
The effects of clinical task interruptions on subsequent performance of a medication pre-administration task
There is a surge of research exploring the role of task interruptions in the manifestation of primary task errors both in controlled experimental settings, and safety critical workplaces such as healthcare. Despite such research providing valuable insights into the disruptive properties of task interruption, and, the importance of considering the likely disruptive consequences of clinical task interruptions in healthcare environments, there is an urgent need for an approach that best mimics complex working environments such as healthcare, whilst allowing better control over experimental variables with minimal constraints. We propose that this can be achieved with ecologically sensitive experimental tasks designed to have high levels of experimental control so that theoretical as well as practical parameters and factors can be tested. We developed a theoretically and ecologically informed procedural memory-based task - the CAMROSE Medication Pre-Administration Task. Results revealed significantly more sequence errors were made on low, moderate and high complex conditions compared to no interruption condition. There was no significant difference in non-sequence errors. Findings reveal the importance of developing ecologically valid tasks to explore non-observable characteristics of clinical task interruptions. Both theoretical and possible practical implications are discussed
Mapping medical careers: Questionnaire assessment of career preferences in medical school applicants and final-year students
BACKGROUND: The medical specialities chosen by doctors for their careers play an important part in the workforce planning of health-care services. However, there is little theoretical understanding of how different medical specialities are perceived or how choices are made, despite there being much work in general on this topic in occupational psychology, which is influenced by Holland's RIASEC (Realistic-Investigative-Artistic-Social-Enterprising-Conventional) typology of careers, and Gottfredson's model of circumscription and compromise. In this study, we use three large-scale cohorts of medical students to produce maps of medical careers. METHODS: Information on between 24 and 28 specialities was collected in three UK cohorts of medical students (1981, 1986 and 1991 entry), in applicants (1981 and 1986 cohorts, N = 1135 and 2032) or entrants (1991 cohort, N = 2973) and in final-year students (N = 330, 376, and 1437). Mapping used Individual Differences Scaling (INDSCAL) on sub-groups broken down by age and sex. The method was validated in a population sample using a full range of careers, and demonstrating that the RIASEC structure could be extracted. RESULTS: Medical specialities in each cohort, at application and in the final-year, were well represented by a two-dimensional space. The representations showed a close similarity to Holland's RIASEC typology, with the main orthogonal dimensions appearing similar to Prediger's derived orthogonal dimensions of 'Things-People' and 'Data-Ideas'. CONCLUSIONS: There are close parallels between Holland's general typology of careers, and the structure we have found in medical careers. Medical specialities typical of Holland's six RIASEC categories are Surgery (Realistic), Hospital Medicine (Investigative), Psychiatry (Artistic), Public Health (Social), Administrative Medicine (Enterprising), and Laboratory Medicine (Conventional). The homology between medical careers and RIASEC may mean that the map can be used as the basis for understanding career choice, and for providing career counselling
Turing Patterns Inside Cells
Concentration gradients inside cells are involved in key processes such as cell division and morphogenesis. Here we show that a model of the enzymatic step catalized by phosphofructokinase (PFK), a step which is responsible for the appearance of homogeneous oscillations in the glycolytic pathway, displays Turing patterns with an intrinsic length-scale that is smaller than a typical cell size. All the parameter values are fully consistent with classic experiments on glycolytic oscillations and equal diffusion coefficients are assumed for ATP and ADP. We identify the enzyme concentration and the glycolytic flux as the possible regulators of the pattern. To the best of our knowledge, this is the first closed example of Turing pattern formation in a model of a vital step of the cell metabolism, with a built-in mechanism for changing the diffusion length of the reactants, and with parameter values that are compatible with experiments. Turing patterns inside cells could provide a check-point that combines mechanical and biochemical information to trigger events during the cell division process
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