1,705 research outputs found
Constraints and Reality Conditions in the Ashtekar Formulation of General Relativity
We show how to treat the constraints and reality conditions in the
-ADM (Ashtekar) formulation of general relativity, for the case of a
vacuum spacetime with a cosmological constant. We clarify the difference
between the reality conditions on the metric and on the triad. Assuming the
triad reality condition, we find a new variable, allowing us to solve the gauge
constraint equations and the reality conditions simultaneously.Comment: LaTeX file, 12 pages, no figures; to appear in Classical and Quantum
Gravit
The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records.
PublishedJournal ArticleBACKGROUND: The risk of cancer with hypercalcaemia in primary care is unknown. METHODS: This was a cohort study using calcium results in patients aged â©Ÿ40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified. RESULTS: Participants (54â267) had calcium results: 1674 (3%) were â©Ÿ2.6âmmolâl(-1). Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17-3.93, P=<0.001; positive predictive value (PPV) 11.5%; females: OR 1.86, 95% CI 1.39-2.50, P<0.001: PPV 4.1%. CONCLUSIONS: Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women
Crustal Accretion in the Gulf of California: An Intermediaterate Spreading Axis
An important objective of Deep Sea Drilling Project
(DSDP) Leg 65 was to study crustal accretion at an ocean
ridge axis with an intermediate-spreading rate for comparison
with previously studied sections displaying slowand
fast-spreading rates. The southern Gulf of California
was selected for this purpose because the basement displays
high seismic velocities (comparable to those observed
for Cretaceous basement in the western North
Atlantic) and high ambient sedimentation rates, which
facilitated penetration of zero-age basement. Four sites
were drilled, forming an axial transect immediately south
of the Tamayo Fracture Zone (Figs. 1 and 2) and providing
a series of characteristic sections into the crust. This
chapter attempts to provide a brief synthesis of the results
from Leg 65, focusing particularly on the lithology,
geochemistry, and paleomagnetic properties of the
cored basement material. From these data, we present
an interpretation of the processes of magmatic evolution
and crustal accretion occurring at the Gulf of California
spreading axis
Salinity from Space Unlocks Satellite-Based Assessment of Ocean Acidification
Approximately a quarter of the carbon dioxide (CO2) that we emit into the atmosphere is absorbed by the ocean. This oceanic uptake of CO2 leads to a change in marine carbonate chemistry resulting in a decrease of seawater pH and carbonate ion concentration, a process commonly called âOcean Acidificationâ. Salinity data are key for assessing the marine carbonate system, and new space-based salinity measurements will enable the development of novel space-based ocean acidification assess- ment. Recent studies have highlighted the need to develop new in situ technology for monitoring ocean acidification, but the potential capabilities of space-based measurements remain largely untapped. Routine measurements from space can provide quasi-synoptic, reproducible data for investigating processes on global scales; they may also be the most efficient way to monitor the ocean surface. As the carbon cycle is dominantly controlled by the balance between the biological and solubility carbon pumps, innovative methods to exploit existing satellite sea surface temperature and ocean color, and new satellite sea surface salinity measurements, are needed and will enable frequent assessment of ocean acidification parameters over large spatial scales
The CMS Tracker Readout Front End Driver
The Front End Driver, FED, is a 9U 400mm VME64x card designed for reading out
the Compact Muon Solenoid, CMS, silicon tracker signals transmitted by the
APV25 analogue pipeline Application Specific Integrated Circuits. The FED
receives the signals via 96 optical fibers at a total input rate of 3.4 GB/sec.
The signals are digitized and processed by applying algorithms for pedestal and
common mode noise subtraction. Algorithms that search for clusters of hits are
used to further reduce the input rate. Only the cluster data along with trigger
information of the event are transmitted to the CMS data acquisition system
using the S-LINK64 protocol at a maximum rate of 400 MB/sec. All data
processing algorithms on the FED are executed in large on-board Field
Programmable Gate Arrays. Results on the design, performance, testing and
quality control of the FED are presented and discussed
Workforce predictive risk modelling: development of a model to identify general practices at risk of a supplyâdemand imbalance
Objective: This study aimed to develop a risk prediction model identifying general practices at risk of workforce supplyâdemand imbalance.
Design: This is a secondary analysis of routine data on general practice workforce, patient experience and registered populations (2012 to 2016), combined with a census of general practitionersâ (GPsâ) career intentions (2016).
Setting/Participants: A hybrid approach was used to develop a model to predict workforce supplyâdemand imbalance based on practice factors using historical data (2012â2016) on all general practices in England (with over 1000 registered patients n=6398). The model was applied to current data (2016) to explore future risk for practices in South West England (n=368).
Primary outcome measure: The primary outcome was a practice being in a state of workforce supplyâdemand imbalance operationally defined as being in the lowest third nationally of access scores according to the General Practice Patient Survey and the highest third nationally according to list size per full-time equivalent GP (weighted to the demographic distribution of registered patients and adjusted for deprivation).
Results: Based on historical data, the predictive model had fair to good discriminatory ability to predict which practices faced supplyâdemand imbalance (area under receiver operating characteristic curve=0.755). Predictions using current data suggested that, on average, practices at highest risk of future supplyâdemand imbalance are currently characterised by having larger patient lists, employing more nurses, serving more deprived and younger populations, and having considerably worse patient experience ratings when compared with other practices. Incorporating findings from a survey of GPâs career intentions made little difference to predictions of future supplyâdemand risk status when compared with expected future workforce projections based only on routinely available data on GPsâ gender and age.
Conclusions: It is possible to make reasonable predictions of an individual general practiceâs future risk of undersupply of GP workforce with respect to its patient population. However, the predictions are inherently limited by the data available
Ephemeris Updates for Seven Selected HATNet Survey Transiting Exoplanets
We refined the ephemeris of seven transiting exoplanets HAT-P-6b, HAT-P-12b,
HAT-P-18b, HAT-P-22b, HAT-P-32b, HAT-P-33b, and HAT-P-52b. We observed 11
transits from eight observatories in different filters for HAT-P-6b and
HAT-P-32b. Also, the Exoplanet Transit Database (ETD) observations for each of
the seven exoplanets were analyzed, and the light curves of five systems were
studied using Transiting light Exoplanet Survey Satellite (TESS) data. We used
Exofast-v1 to simulate these ground- and space-based light curves and estimate
mid-transit times. We obtained a total of 11, 175 and 67 mid-transit times for
these seven exoplanets from our observations, ETD and TESS data, respectively,
along with 155 mid-transit times from the literature. Then, we generated
transit timing variation (TTV) diagrams for each using derived mid-transit
times as well as those found in the literature. The systems' linear ephemeris
was then refined and improved using the Markov Chain Monte Carlo (MCMC) method.
All of the studied exoplanets, with the exception of the HAT-P-12b system,
displayed an increasing trend in the orbital period in the TTV diagrams.Comment: 11 Pages, submitted to the Astrophysics journa
Healthy publics: Enabling cultures and environments for health
This is the final version of the article. Available from the publisher via the DOI in this recordDespite extraordinary advances in biomedicine and associated gains in human
health and well-being, a growing number of health and well-being related challenges have
remained or emerged in recent years. These challenges are often âmore than biomedicalâ in
complexion, being social, cultural and environmental in terms of their key drivers and
determinants, and underline the necessity of a concerted policy focus on generating healthy
societies. Despite the apparent agreement on this diagnosis, the means to produce change
are seldom clear, even when the turn to health and well-being requires sizable shifts in our
understandings of public health and research practices. This paper sets out a platform from
which research approaches, methods and translational pathways for enabling health and wellbeing
can be built. The term âhealthy publicsâ allows us to shift the focus of public health away
from âthe publicâ or individuals as targets for intervention, and away from the view that culture
acts as a barrier to efficient biomedical intervention, towards a greater recognition of the
public struggles that are involved in raising health issues, questioning what counts as healthy
and unhealthy and assembling the evidence and experience to change practices and outcomes.
Creating the conditions for health and well-being, we argue, requires an engaged
research process in which public experiments in building and repairing social and material
relations are staged and sustained even if, and especially when, the fates of those publics
remain fragile and buffeted by competing and often more powerful public formations.The authors would like to acknowledge the Wellcome Trust for funding the Centre for Cultures and Environments of Health (grant reference 203109/Z/16/Z). All authors are lead members of the Wellcome Centre for Cultures and Environments of Health at the University of Exeter
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