315 research outputs found
Evaluation of a direct access cardiac arrhythmia monitoring service
Background: This paper describes the clinical outcomes from a novel direct access arrhythmia
monitoring service.
Methods: The study was carried out in the north of Scotland. Data was collected over
a 29 month period between 18 June 2008 and 8 November 2010 from consecutive cases from
two groups of patients, general practitioner (GP) direct access and ‘redirected’ consultant
referrals. Monitor test results, frequency of arrhythmias requiring further care and clinic
attendances were recorded. Statistical differences were analyzed using Χ2, Fisher’s and Student’s
t-test as appropriate with the significance taken at the 0.05 level.
Results: 239 patients were referred from 47 GP practices. There were 165 (69%) referrals
through the ‘direct’ and 72 (31%) through the ‘redirected’ route. The average age was 55.5 ±
± 16.7 years with 84 (35.1%) males. 127 (53.1%) had a patient activated event recording and
the remaining 112 (46.9%) had Holter monitoring. Of the 239 patients, only nine (3.8%) cases
required referral to a consultant cardiologist. Of these, three were directly returned to GP care
without consultant clinic review. Six patients with significant arrhythmias were reviewed at
cardiology clinic. There were no adverse events.
Conclusions: Direct access for cardiac arrhythmia monitoring seems to provide an effective
mechanism for diverting inappropriate or non-essential referrals away from the cardiology
clinic. (Cardiol J 2012; 19, 1: 70–75
How Low Can You Go? The Photoeccentric Effect for Planets of Various Sizes
It is well-known that the light curve of a transiting planet contains
information about the planet's orbital period and size relative to the host
star. More recently, it has been demonstrated that a tight constraint on an
individual planet's eccentricity can sometimes be derived from the light curve
via the "photoeccentric effect," the effect of a planet's eccentricity on the
shape and duration of its light curve. This has only been studied for large
planets and high signal-to-noise scenarios, raising the question of how well it
can be measured for smaller planets or low signal-to-noise cases. We explore
the limits of the photoeccentric effect over a wide range of planet parameters.
The method hinges upon measuring directly from the light curve, where
is the ratio of the planet's speed (projected on the plane of the sky) during
transit to the speed expected for a circular orbit. We find that when the
signal-to-noise in the measurement of is , the ability to measure
eccentricity with the photoeccentric effect decreases. We develop a "rule of
thumb" that for per-point relative photometric uncertainties , the critical values of planet-star radius ratio
are for Kepler-like 30-minute
integration times. We demonstrate how to predict the best-case uncertainty in
eccentricity that can be found with the photoeccentric effect for any light
curve. This clears the path to study eccentricities of individual planets of
various sizes in the Kepler sample and future transit surveys
Formation of Super-Earths
Super-Earths are the most abundant planets known to date and are
characterized by having sizes between that of Earth and Neptune, typical
orbital periods of less than 100 days and gaseous envelopes that are often
massive enough to significantly contribute to the planet's overall radius.
Furthermore, super-Earths regularly appear in tightly-packed multiple-planet
systems, but resonant configurations in such systems are rare. This chapters
summarizes current super-Earth formation theories. It starts from the formation
of rocky cores and subsequent accretion of gaseous envelopes. We follow the
thermal evolution of newly formed super-Earths and discuss their atmospheric
mass loss due to disk dispersal, photoevaporation, core-cooling and collisions.
We conclude with a comparison of observations and theoretical predictions,
highlighting that even super-Earths that appear as barren rocky cores today
likely formed with primordial hydrogen and helium envelopes and discuss some
paths forward for the future.Comment: Invited review accepted for publication in the 'Handbook of
Exoplanets,' Planet Formation section, Springer Reference Works, Juan Antonio
Belmonte and Hans Deeg, Ed
Analysis of common genetic variation and rare CNVs in the Australian Autism Biobank.
BackgroundAutism spectrum disorder (ASD) is a complex neurodevelopmental condition whose biological basis is yet to be elucidated. The Australian Autism Biobank (AAB) is an initiative of the Cooperative Research Centre for Living with Autism (Autism CRC) to establish an Australian resource of biospecimens, phenotypes and genomic data for research on autism.MethodsGenome-wide single-nucleotide polymorphism genotypes were available for 2,477 individuals (after quality control) from 546 families (436 complete), including 886 participants aged 2 to 17Â years with diagnosed (nâ=â871) or suspected (nâ=â15) ASD, 218 siblings without ASD, 1,256 parents, and 117 unrelated children without an ASD diagnosis. The genetic data were used to confirm familial relationships and assign ancestry, which was majority European (nâ=â1,964 European individuals). We generated polygenic scores (PGS) for ASD, IQ, chronotype and height in the subset of Europeans, and in 3,490 unrelated ancestry-matched participants from the UK Biobank. We tested for group differences for each PGS, and performed prediction analyses for related phenotypes in the AAB. We called copy-number variants (CNVs) in all participants, and intersected these with high-confidence ASD- and intellectual disability (ID)-associated CNVs and genes from the public domain.ResultsThe ASD (pâ=â6.1e-13), sibling (pâ=â4.9e-3) and unrelated (pâ=â3.0e-3) groups had significantly higher ASD PGS than UK Biobank controls, whereas this was not the case for height-a control trait. The IQ PGS was a significant predictor of measured IQ in undiagnosed children (râ=â0.24, pâ=â2.1e-3) and parents (râ=â0.17, pâ=â8.0e-7; 4.0% of variance), but not the ASD group. Chronotype PGS predicted sleep disturbances within the ASD group (râ=â0.13, pâ=â1.9e-3; 1.3% of variance). In the CNV analysis, we identified 13 individuals with CNVs overlapping ASD/ID-associated CNVs, and 12 with CNVs overlapping ASD/ID/developmental delay-associated genes identified on the basis of de novo variants.LimitationsThis dataset is modest in size, and the publicly-available genome-wide-association-study (GWAS) summary statistics used to calculate PGS for ASD and other traits are relatively underpowered.ConclusionsWe report on common genetic variation and rare CNVs within the AAB. Prediction analyses using currently available GWAS summary statistics are largely consistent with expected relationships based on published studies. As the size of publicly-available GWAS summary statistics grows, the phenotypic depth of the AAB dataset will provide many opportunities for analyses of autism profiles and co-occurring conditions, including when integrated with other omics datasets generated from AAB biospecimens (blood, urine, stool, hair)
Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer
INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-ÎșB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS â 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Prehospital Electronic Patient Care Report Systems: Early Experiences from Emergency Medical Services Agency Leaders
Background: As the United States embraces electronic health records (EHRs), improved emergency medical services (EMS) information systems are also a priority; however, little is known about the experiences of EMS agencies as they adopt and implement electronic patient care report (e-PCR) systems. We sought to characterize motivations for adoption of e-PCR systems, challenges associated with adoption and implementation, and emerging implementation strategies. Methods: We conducted a qualitative study using semi-structured in-depth interviews with EMS agency leaders. Participants were recruited through a web-based survey of National Association of EMS Physicians (NAEMSP) members, a didactic session at the 2010 NAEMSP Annual Meeting, and snowball sampling. Interviews lasted approximately 30 minutes, were recorded and professionally transcribed. Analysis was conducted by a five-person team, employing the constant comparative method to identify recurrent themes. Results: Twenty-three interviewees represented 20 EMS agencies from the United States and Canada; 14 EMS agencies were currently using e-PCR systems. The primary reason for adoption was the potential for e-PCR systems to support quality assurance efforts. Challenges to e-PCR system adoption included those common to any health information technology project, as well as challenges unique to the prehospital setting, including: fear of increased ambulance run times leading to decreased ambulance availability, difficulty integrating with existing hospital information systems, and unfunded mandates requiring adoption of e-PCR systems. Three recurring strategies emerged to improve e-PCR system adoption and implementation: 1) identify creative funding sources; 2) leverage regional health information organizations; and 3) build internal information technology capacity. Conclusion: EMS agencies are highly motivated to adopt e-PCR systems to support quality assurance efforts; however, adoption and implementation of e-PCR systems has been challenging for many. Emerging strategies from EMS agencies and others that have successfully implemented EHRs may be useful in expanding e-PCR system use and facilitating this transition for other EMS agencies
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Autism diagnosis differentiates neurophysiological responses to faces in adults with tuberous sclerosis complex
- Background: Autism spectrum disorder (ASD) is a common and highly heritable neurodevelopmental disorder that is likely to be the outcome of complex aetiological mechanisms. One strategy to provide insight is to study ASD within tuberous sclerosis complex (TSC), a rare disorder with a high incidence of ASD, but for which the genetic cause is determined. Individuals with ASD consistently demonstrate face processing impairments, but these have not been examined in adults with TSC using event-related potentials (ERPs) that are able to capture distinct temporal stages of processing.
- Methods: For adults with TSC (nâ=â14), 6 of which had a diagnosis of ASD, and control adults (nâ=â13) passively viewed upright and inverted human faces with direct or averted gaze, with concurrent EEG recording. Amplitude and latency of the P1 and N170 ERPs were measured.
- Results: Individuals with TSCâ+âASD exhibited longer N170 latencies to faces compared to typical adults. Typical adults and adults with TSC-only exhibited longer N170 latency to inverted versus upright faces, whereas individuals with TSCâ+âASD did not show latency differences according to face orientation. In addition, individuals with TSCâ+âASD showed increased N170 latency to averted compared to direct gaze, which was not demonstrated in typical adults. A reduced lateralization was shown for the TSCâ+âASD groups on P1 and N170 amplitude.
- Conclusions: The findings suggest that individuals with TSCâ+âASD may have similar electrophysiological abnormalities to idiopathic ASD and are suggestive of developmental delay. Identifying brain-based markers of ASD that are similar in TSC and idiopathic cases is likely to help elucidate the risk pathways to ASD
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