2,290 research outputs found
Spatially resolved kinematics in the central 1 kpc of a compact star-forming galaxy at z=2.3 from ALMA CO observations
We present high spatial resolution (FWHM0.14'') observations of the
CO() line in GDS-14876, a compact star-forming galaxy at with
total stellar mass of . The spatially resolved
velocity map of the inner ~kpc reveals a continous velocity
gradient consistent with the kinematics of a rotating disk with km s and . The
gas-to-stellar ratios estimated from CO() and the dust continuum emission
span a broad range, and
, but are nonetheless consistent given the
uncertainties in the conversion factors. The dynamical modeling yields a
dynamical mass of which is
lower, but still consistent with the baryonic mass, (M=
M + M/M), if the smallest
CO-based gas fraction is assumed. Despite a low, overall gas fraction, the
small physical extent of the dense, star-forming gas probed by CO(),
smaller than the stellar size, implies a strong concentration
that increases the gas fraction up to
in the central 1 kpc. Such a gas-rich center, coupled with a high
star-formation rate, SFR 500 M yr, suggests that
GDS-14876 is quickly assembling a dense stellar component (bulge) in a strong
nuclear starburst. Assuming its gas reservoir is depleted without
replenishment, GDS-14876 will quickly ( Myr) become a
compact quiescent galaxy that could retain some fraction of the observed
rotational support.Comment: Accepted for Publication in ApJL. Kinematic maps are shown in Figures
2 and
Creating a sport and exercise medicine undergraduate syllabus: a delphi study
Background Sport and Exercise Medicine (SEM) is a growing speciality in the United Kingdom (UK). This growth has not been replicated in SEM teaching at an undergraduate level and SEM-related topics in schools of medicine in the UK are under-represented. As SEM continues to develop as a specialty it is important to consider how it is embedded at all levels of training. The aim of this project was to establish a consensus on SEM-related skills and knowledge relevant for undergraduate medical students in the UK, ultimately creating a curriculum of learning objectives (LOs). Methods A modified Delphi survey was utilised to seek consensus on LOs suitable for incorporation into UK medical school curricula. An expert panel with adequate knowledge in the field was recruited. The initial curriculum was created by the research team using already established postgraduate SEM curricula. All learning objectives were sent to the expert panel for opinions in phases. Levels of agreement and comments made by the expert panel were reviewed after each phase until a consensus on each learning objective was made. Results The expert panel was made up of 45 individuals, with 35 also completing phase 2 (78% retention rate). The initial curriculum contained 58 learning objectives separated into 9 themes. In phase 1 31% (18/58) were accepted outright, 48% (28/58) were altered and 19% (11/58) were rejected. Two additional learning objectives were added. Of the 49 LOs included in phase 2, 98% (48/49) were accepted. The final curriculum was made up of 9 sub-themes and 48 LOs. Conclusion Sport and Exercise Medicine is a broad ranging and rapidly growing speciality. It is important to establish SEM education in all levels of medical education, including undergraduate level. This is the first published version of a Delphi SEM curriculum for undergraduate medical teaching
Rapid interrogation of the physical and chemical characteristics of salbutamol sulphate aerosol from a pressurised metered-dose inhaler (pMDI)
Individual micron-sized solid particles from a Salamols pharmaceutical inhaler are stably captured in air using an optical trap for the first time. Raman spectroscopy of the levitated particles allows online interrogation of composition and deliquescent phase change within a high humidity environment that mimics the particle’s travel from inhaler to lun
Comprehensive Observations of the Bright and Energetic Type Iax SN 2012Z: Interpretation as a Chandrasekhar Mass White Dwarf Explosion
We present UV through NIR broad-band photometry, and optical and NIR
spectroscopy of Type Iax supernova 2012Z. The data set consists of both early
and late-time observations, including the first late phase NIR spectrum
obtained for a spectroscopically classified SN Iax. Simple model calculations
of its bolometric light curve suggest SN 2012Z produced ~0.3 M_sun of (56)Ni,
ejected about a Chandrasekhar mass of material, and had an explosion energy of
~10^51 erg, making it one of the brightest and most energetic SN Iax yet
observed. The late phase NIR spectrum of SN 2012Z is found to broadly resemble
similar epoch spectra of normal SNe Ia; however, like other SNe Iax,
corresponding visual-wavelength spectra differ substantially compared to all
supernova types. Constraints from the distribution of IMEs, e.g. silicon and
magnesium, indicate that the outer ejecta did not experience significant mixing
during or after burning, and the late phase NIR line profiles suggests most of
the (56)Ni is produced during high density burning. The various observational
properties of SN 2012Z are found to be consistent with the theoretical
expectations of a Chandrasekhar mass white dwarf progenitor that experiences a
pulsational delayed detonation, which produced several tenths of a solar mass
of (56)Ni during the deflagration burning phase and little (or no) (56)Ni
during the detonation phase. Within this scenario only a moderate amount of
Rayleigh-Taylor mixing occurs both during the deflagration and fallback phase
of the pulsation, and the layered structure of the IMEs is a product of the
subsequent denotation phase. The fact that the SNe Iax population does not
follow a tight brightness-decline relation similar to SNe Ia can then be
understood in the framework of variable amounts of mixing during pulsational
rebound and variable amounts of (56)Ni production during the early subsonic
phase of expansion.Comment: Submitted to A&A, manuscript includes response to referee's comments.
39 pages, including 16 figures, 9 table
Action conditional recurrent Kalman networks for forward and inverse dynamics learning
Estimating accurate forward and inverse dynamics models is a crucial component of model-based control for sophisticated robots such as robots driven by hydraulics, artificial muscles, or robots dealing with different contact situations. Analytic models to such processes are often unavailable or inaccurate due to complex hysteresis effects, unmodelled friction and stiction phenomena, and unknown effects during contact situations. A promising approach is to obtain spatio-temporal models in a data-driven way using recurrent neural networks, as they can overcome those issues. However, such models often do not meet accuracy demands sufficiently, degenerate in performance for the required high sampling frequencies and cannot provide uncertainty estimates. We adopt a recent probabilistic recurrent neural network architecture, called Recurrent Kalman Networks (RKNs), to model learning by conditioning its transition dynamics on the control actions. RKNs outperform standard recurrent networks such as LSTMs on many state estimation tasks. Inspired by Kalman filters, the RKN provides an elegant way to achieve action conditioning within its recurrent cell by leveraging additive interactions between the current latent state and the action variables. We present two architectures, one for forward model learning and one for inverse model learning. Both architectures significantly outperform existing model learning frameworks as well as analytical models in terms of prediction performance on a variety of real robot dynamics models
A Theory of Sampling for Continuous-time Metric Temporal Logic
This paper revisits the classical notion of sampling in the setting of
real-time temporal logics for the modeling and analysis of systems. The
relationship between the satisfiability of Metric Temporal Logic (MTL) formulas
over continuous-time models and over discrete-time models is studied. It is
shown to what extent discrete-time sequences obtained by sampling
continuous-time signals capture the semantics of MTL formulas over the two time
domains. The main results apply to "flat" formulas that do not nest temporal
operators and can be applied to the problem of reducing the verification
problem for MTL over continuous-time models to the same problem over
discrete-time, resulting in an automated partial practically-efficient
discretization technique.Comment: Revised version, 43 pages
How do women prepare for pregnancy? Preconception experiences of women attending antenatal services and views of health professionals
Copyright: © 2014 Stephenson et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Main objective - To determine the extent to which women plan and prepare for pregnancy.
Methods - Cross-sectional questionnaire survey of pregnant women attending three maternity services in London about knowledge and uptake of preconception care; including a robust measure of pregnancy planning, and phone interviews with a range of health care professionals.
Main results - We recruited 1173/1288 (90%) women, median age of 32 years. 73% had clearly planned their pregnancy, 24% were ambivalent and only 3% of pregnancies were unplanned. 51% of all women and 63% of those with a planned pregnancy took folic acid before pregnancy. 21% of all women reported smoking and 61% reported drinking alcohol in the 3 months before pregnancy; 48% of smokers and 41% of drinkers reduced or stopped before pregnancy. The 51% of all women who reported advice from a health professional before becoming pregnant were more likely to adopt healthier behaviours before pregnancy [adjusted odds ratios for greatest health professional input compared with none were 2.34 (95% confidence interval 1.54–3.54) for taking folic acid and 2.18 (95% CI 1.42–3.36) for adopting a healthier diet before pregnancy]. Interviews with 20 health professionals indicated low awareness of preconception health issues, missed opportunities and confusion about responsibility for delivery of preconception care.
Significance of the findings - Despite a high level of pregnancy planning, awareness of preconception health among women and health professionals is low, and responsibility for providing preconception care is unclear. However, many women are motivated to adopt healthier behaviours in the preconception period, as indicated by halving of reported smoking rates in this study. The link between health professional input and healthy behaviour change before pregnancy is a new finding that should invigorate strategies to improve awareness and uptake of pre-pregnancy health care, and bring wider benefits for public health.Department of Healt
Complement component 3 levels in the cerebrospinal fluid of cognitively intact elderly individuals with major depressive disorder
Late-life major depression (LLMD) is a risk factor for the development of mild cognitive impairment and dementia, including Alzheimer's disease (AD) and vascular dementia. Immune dysregulation and changes in innate immune responses in particular, have been implicated in the pathophysiology of both LLMD and AD. Complement system, a key component of the innate immune mechanism, is known to play an important role in synaptic plasticity and cognitive functions. However, its role in LLMD remains unknown. In the present study, we examined the levels of complement component 3 (C3, the convergence point of all complement activation pathways) in the cerebrospinal fluid (CSF) of elderly depressed subjects compared to healthy controls; as well as the relationship of CSF C3 levels with amyloid-beta (Aβ42 and Aβ40), total tau (T-tau) and phosphorylated tau (P-tau) proteins and cognition scores. CSF was obtained from 50 cognitively intact volunteers (major depression group, N = 30; comparison group, N = 20) and analyzed for levels of C3 by ELISA. C3 levels were marginally lower in the major depression group relative to the comparison group. We did not find any significant association of C3 with the AD biomarkers Aβ42 reflecting plaque pathology, P-tau related to tau pathology or the neurodegeneration biomarker T-tau. In contrast, C3 was positively correlated with CSF Aβ40, which may reflect Aβ deposition in cerebral vessel walls. We observed a negative correlation between C3 levels and Total Recall on the Buschke Selective Reminding Test (BSRT) for memory performance in the depressed subjects when controlling for education. This initial evidence on C3 status in LLMD subjects may have implications for our understanding of the pathophysiology of major depression especially in late life
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