34 research outputs found
Recent results from parton cascade and microscopic transport
Parton cascade is a microscopic transport approach for the study of the
space-time evolution of the Quark-Gluon Plasma produced in relativistic heavy
ion collisions and its experimental manifestations. In the following, parton
cascade calculations on elliptic flow and thermalization will be discussed.
Dynamical evolution is shown to be important for the production of elliptic
flow including the scaling and the breaking of the scaling of elliptic flow.
The degree of thermalization is estimated using both an elastic parton cascade
and a radiative transport model. A longitudinal to transverse pressure ratio,
, is shown to be expected in the central cell in central
collisions. This provides information on viscous corrections to the ideal
hydrodynamical approach.Comment: Presented at Hot Quarks 2008, Estes Park, Colorado, USA, 18-23 August
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Low-mass pre--main-sequence stars in the Magellanic Clouds
[Abridged] The stellar Initial Mass Function (IMF) suggests that sub-solar
stars form in very large numbers. Most attractive places for catching low-mass
star formation in the act are young stellar clusters and associations, still
(half-)embedded in star-forming regions. The low-mass stars in such regions are
still in their pre--main-sequence (PMS) evolutionary phase. The peculiar nature
of these objects and the contamination of their samples by the evolved
populations of the Galactic disk impose demanding observational techniques for
the detection of complete numbers of PMS stars in the Milky Way. The Magellanic
Clouds, the companion galaxies to our own, demonstrate an exceptional star
formation activity. The low extinction and stellar field contamination in
star-forming regions of these galaxies imply a more efficient detection of
low-mass PMS stars than in the Milky Way, but their distance from us make the
application of special detection techniques unfeasible. Nonetheless, imaging
with the Hubble Space Telescope yield the discovery of solar and sub-solar PMS
stars in the Magellanic Clouds from photometry alone. Unprecedented numbers of
such objects are identified as the low-mass stellar content of their
star-forming regions, changing completely our picture of young stellar systems
outside the Milky Way, and extending the extragalactic stellar IMF below the
persisting threshold of a few solar masses. This review presents the recent
developments in the investigation of PMS stars in the Magellanic Clouds, with
special focus on the limitations by single-epoch photometry that can only be
circumvented by the detailed study of the observable behavior of these stars in
the color-magnitude diagram. The achieved characterization of the low-mass PMS
stars in the Magellanic Clouds allowed thus a more comprehensive understanding
of the star formation process in our neighboring galaxies.Comment: Review paper, 26 pages (in LaTeX style for Springer journals), 4
figures. Accepted for publication in Space Science Review
Clustered mutations in the GRIK2 kainate receptor subunit gene underlie diverse neurodevelopmental disorders (vol 108, pg 1692, 2021)
Neurolog
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Dynamic compressive properties of nickel-based honeycomb sandwich and two-layered sandwich
The behavior of nickel based super-alloy sandwich and two-layered sandwich at high strain rate 1000/s-6700/s were studied systematically using large caliber Split Hopkinson Pressure Bar (SHPB). Semiconductor strain gauges, PVDF stress gauges and pulse shaping technique were employed to improve the SHPB test. The results shows that both two kinds of honeycomb materials are strain rate insensitive under high strain rate, skin sheet damages at different forms with increasing of strain rate
Crystal structure of 1-(diphenylmethylene)-2-(thiazolo[4,5-b]pyridin- 2(3H)-ylidene)hydrazine, C19H14N4S
Modifiable risk factors in the first 1000 days for subsequent risk of childhood overweight in an Asian cohort: Significance of parental overweight status
Background/Objective:Many studies have identified early-life risk factors for subsequent childhood overweight/obesity, but few have evaluated how they combine to influence risk of childhood overweight/obesity. We examined associations, individually and in combination, of potentially modifiable risk factors in the first 1000 days after conception with childhood adiposity and risk of overweight/obesity in an Asian cohort.Methods:Six risk factors were examined: Maternal pre-pregnancy overweight/obesity (body mass index (BMI) ≥425 kg m-2), paternal overweight/obesity at 24 months post delivery, maternal excessive gestational weight gain, raised maternal fasting glucose during pregnancy (≥45.1 mmol l-1), breastfeeding duration <4 months and early introduction of solid foods (<4 months). Associations between number of risk factors and adiposity measures (BMI, waist-to-height ratio (WHtR), sum of skinfolds (SSFs), fat mass index (FMI) and overweight/obesity) at 48 months were assessed using multivariable regression models.Results:Of 858 children followed up at 48 months, 172 (19%) had none, 274 (32%) had 1, 244 (29%) had 2, 126 (15%) had 3 and 42 (5%) had ≥44 risk factors. Adjusting for confounders, significant graded positive associations were observed between number of risk factors and adiposity outcomes at 48 months. Compared with children with no risk factors, those with four or more risk factors had s.d. unit increases of 0.78 (95% confidence interval 0.41-1.15) for BMI, 0.79 (0.41-1.16) for WHtR, 0.46 (0.06-0.83) for SSF and 0.67 (0.07-1.27) for FMI. The adjusted relative risk of overweight/obesity in children with four or more risk factors was 11.1(2.5-49.1) compared with children with no risk factors. Children exposed to maternal pre-pregnancy (11.8(9.8-13.8)%) or paternal overweight status (10.6(9.6-11.6)%) had the largest individual predicted probability of child overweight/obesity.Conclusions:Early-life risk factors added cumulatively to increase childhood adiposity and risk of overweight/obesity. Early-life and preconception intervention programmes may be more effective in preventing overweight/obesity if they concurrently address these multiple modifiable risk factors.</p