1,813 research outputs found
Constraining dark energy fluctuations with supernova correlations
We investigate constraints on dark energy fluctuations using type Ia
supernovae. If dark energy is not in the form of a cosmological constant, that
is if the equation of state is not equal to -1, we expect not only temporal,
but also spatial variations in the energy density. Such fluctuations would
cause local variations in the universal expansion rate and directional
dependences in the redshift-distance relation. We present a scheme for relating
a power spectrum of dark energy fluctuations to an angular covariance function
of standard candle magnitude fluctuations. The predictions for a
phenomenological model of dark energy fluctuations are compared to
observational data in the form of the measured angular covariance of Hubble
diagram magnitude residuals for type Ia supernovae in the Union2 compilation.
The observational result is consistent with zero dark energy fluctuations.
However, due to the limitations in statistics, current data still allow for
quite general dark energy fluctuations as long as they are in the linear
regime.Comment: 18 pages, 6 figures, matches the published versio
Behaviour management problems in Finnish children with operated congenital heart disease : a practice-based study
Purpose This retrospective, practice-based study investigates behaviour management problems (BMPs) in dental care among Finnish children with operated congenital heart disease (CHD). Methods All the heart-operated children born between the years 1997 and 1999 were identified in the national ProCardio database (n = 570). Primary dental care records were requested from this population and were eventually received from 211 patients. Information on gender, diagnosis, number of heart operations and perioperative care were collected from the ProCardio database, and the CHDs were categorised as shunting/stenotic/complex/other defects. Data on BMP/dental fear, oral conscious sedation, dental general anaesthesia (DGA) and past and present caries indices at 6, 12 and 15 years (d/D, dmft/DMFT) were assessed. Results Notes on behaviour management problems or dental fear were found in 19% of the study population. BMPs in dental care were more frequent among boys. Children with re-operations, longer post-operative intensive care stay and hospitalisation, and complications had not more BMP than others. Those children diagnosed with syndromes had more BMP often than the rest. Past and present caries experience were significantly associated with BMP, need of oral conscious sedation and DGA. Oral conscious sedation, nitrogen oxide sedation and dental general anaesthesia were used in 17/211, 2/221 and 24/211 CHD patients, respectively. Conclusion Dental caries remains a main factor associated with BMP in the CHD population. Need for oral conscious sedation and DGA were rather common. To maintain a good oral health and to avoid development of BMP, CHD children benefit from focus in health promotion and preventive care.Peer reviewe
Does the shoe fit? Real versus imagined ecological footprints
Linus Blomqvist, Barry W. Brook, Erle C. Ellis, Peter M. Kareiva, Ted Nordhaus, Michael Shellenberge
Dental caries and attendance to dental care in Finnish children with operated congenital heart disease. A practice based follow-up study
Purpose Oral health of children with congenital heart disease (CHD) is of utmost importance. This study aimed to investigate the prevalence of dental caries and attendance to dental care in Finnish heart-operated CHD patients born in 1997-1999. Methods The cohort of children born in 1997-1999 was selected using a national register on all heart-operated children in Finland. Gender, general health problems, diagnosis, type of the heart defect (shunting, stenotic and complex defects), and number of operations were available and included in the analyses. Dental records from primary health care were collected from municipalities with their permission. The data comprised of the number of dental examinations and data on caries status (dt, DT, dmft, DMFT) at the age of 7 (grade 1), 11 (grade 5) and 15 (grade 8) years and at the most recent examination. The control group consisted of dental data on patients born in 1997-1999 provided by the City of Oulu, Finland (n = 3356). Results Oral patient records of 215/570 children were obtained. The difference between the defect types was statistically significant both for DT (p = 0.046) and DMFT (p = 0.009) at the age of 15 (grade 8). The prevalence of caries did not differ between the study population and the controls. High present and past caries experiences were not associated with higher number of visits to oral health care, especially to oral hygienist, or with oral health promotion. National obligations concerning dental visits were not implemented in all municipalities. Conclusion There seems to be a need for oral health promotion and preventive means implemented by oral hygienists among those with CHD.Peer reviewe
Measuring dark energy spatial inhomogeneity with supernova data
The gravitational lensing distortion of distant sources by the large-scale
distribution of matter in the Universe has been extensively studied. In
contrast, very little is known about the effects due to the large-scale
distribution of dark energy. We discuss the use of Type Ia supernovae as probes
of the spatial inhomogeneity and anisotropy of dark energy. We show that a
shallow, almost all-sky survey can limit rms dark energy fluctuations at the
horizon scale down to a fractional energy density of ~10^-4Comment: 4 pages; PRL submitte
Realistic Shell-Model Calculations for Proton-Rich N=50 Isotones
The structure of the N=50 isotones 98Cd, 97Ag, and 96Pd is studied in terms
of shell model employing a realistic effective interaction derived from the
Bonn-A nucleon-nucleon potential. The single-hole energies are fixed by
resorting to an analysis of the low-energy spectra of the isotones with A>= 91.
Comparison shows that our results are in very satisfactory agreement with the
available experimental data. This supports confidence in the predictions of our
calculationsComment: 8 pages, 3 figures, to be published on Journal of Physics
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