55 research outputs found
Non-Gaussian Error Contribution to Likelihood Analysis of the Matter Power Spectrum
We study the sample variance of the matter power spectrum for the standard
Lambda Cold Dark Matter universe. We use a total of 5000 cosmological N-body
simulations to study in detail the distribution of best-fit cosmological
parameters and the baryon acoustic peak positions. The obtained distribution is
compared with the results from the Fisher matrix analysis with and without
including non-Gaussian errors. For the Fisher matrix analysis, we compute the
derivatives of the matter power spectrum with respect to cosmological
parameters using directly full nonlinear simulations. We show that the
non-Gaussian errors increase the unmarginalized errors by up to a factor 5 for
k_{max}=0.4h/Mpc if there is only one free parameter provided other parameters
are well determined by external information. On the other hand, for
multi-parameter fitting, the impact of the non-Gaussian errors is significantly
mitigated due to severe parameter degeneracies in the power spectrum. The
distribution of the acoustic peak positions is well described by a Gaussian
distribution, with its width being consistent with the statistical interval
predicted from the Fisher matrix. We also examine systematic bias in the
best-fit parameter due to the non-Gaussian errors. The bias is found to be
smaller than the 1 sigma statistical error for both the cosmological parameters
and the acoustic scale positions.Comment: 12 pages, 10 figures, accepted for publication in ApJ, minor change
Simulations of Baryon Acoustic Oscillations II: Covariance matrix of the matter power spectrum
We use 5000 cosmological N-body simulations of 1(Gpc/h)^3 box for the
concordance LCDM model in order to study the sampling variances of nonlinear
matter power spectrum. We show that the non-Gaussian errors can be important
even on large length scales relevant for baryon acoustic oscillations (BAO).
Our findings are (1) the non-Gaussian errors degrade the cumulative
signal-to-noise ratios (S/N) for the power spectrum amplitude by up to a factor
of 2 and 4 for redshifts z=1 and 0, respectively. (2) There is little
information on the power spectrum amplitudes in the quasi-nonlinear regime,
confirming the previous results. (3) The distribution of power spectrum
estimators at BAO scales, among the realizations, is well approximated by a
Gaussian distribution with variance that is given by the diagonal covariance
component. (4) For the redshift-space power spectrum, the degradation in S/N by
non-Gaussian errors is mitigated due to nonlinear redshift distortions. (5) For
an actual galaxy survey, the additional shot noise contamination compromises
the cosmological information inherent in the galaxy power spectrum, but also
mitigates the impact of non-Gaussian errors. The S/N is degraded by up to 30%
for a WFMOS-type survey. (6) The finite survey volume causes additional
non-Gaussian errors via the correlations of long-wavelength fluctuations with
the fluctuations we want to measure, further degrading the S/N values by about
30% even at high redshift z=3.Comment: submitted to ApJ, 14 pages, 12 figures. The full halo model is
included. Minor changes also made, and references adde
The Hyper Suprime-Cam SSP Survey: Overview and Survey Design
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of
the 8.2m Subaru telescope on the summit of Maunakea in Hawaii. A team of
scientists from Japan, Taiwan and Princeton University is using HSC to carry
out a 300-night multi-band imaging survey of the high-latitude sky. The survey
includes three layers: the Wide layer will cover 1400 deg in five broad
bands (), with a point-source depth of . The
Deep layer covers a total of 26~deg in four fields, going roughly a
magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter
still in two pointings of HSC (a total of 3.5 deg). Here we describe the
instrument, the science goals of the survey, and the survey strategy and data
processing. This paper serves as an introduction to a special issue of the
Publications of the Astronomical Society of Japan, which includes a large
number of technical and scientific papers describing results from the early
phases of this survey.Comment: 14 pages, 7 figures, 5 tables. Corrected for a typo in the
coordinates of HSC-Wide spring equatorial field in Table
EGUIDE project and treatment guidelines
Background
Clinical practice guidelines for schizophrenia and major depressive disorder have been published. However, these have not had sufficient penetration in clinical settings. We developed the Effectiveness of Guidelines for Dissemination and Education in Psychiatric Treatment (EGUIDE) project as a dissemination and education programme for psychiatrists.
Aims
The aim of this study is to assess the effectiveness of the EGUIDE project on the subjective clinical behaviour of psychiatrists in accordance with clinical practice guidelines before and 1 and 2 years after participation in the programmes.
Method
A total of 607 psychiatrists participated in this study during October 2016 and March 2019. They attended both 1-day educational programmes based on the clinical practice guidelines for schizophrenia and major depressive disorder, and answered web questionnaires about their clinical behaviours before and 1 and 2 years after attending the programmes. We evaluated the changes in clinical behaviours in accordance with the clinical practice guidelines between before and 2 years after the programme.
Results
All of the scores for clinical behaviours in accordance with clinical practice guidelines were significantly improved after 1 and 2 years compared with before attending the programmes. There were no significant changes in any of the scores between 1 and 2 years after attending.
Conclusions
All clinical behaviours in accordance with clinical practice guidelines improved after attending the EGUIDE programme, and were maintained for at least 2 years. The EGUIDE project could contribute to improved guideline-based clinical behaviour among psychiatrists
EGUIDE project and treatment guidelines
Aim: Although treatment guidelines for pharmacological therapy for schizophrenia and major depressive disorder have been issued by the Japanese Societies of Neuropsychopharmacology and Mood Disorders, these guidelines have not been well applied by psychiatrists throughout the nation. To address this issue, we developed the âEffectiveness of Guidelines for Dissemination and Education in Psychiatric Treatment (EGUIDE)â integrated education programs for psychiatrists to disseminate the clinical guidelines. Additionally, we conducted a systematic efficacy evaluation of the programs.
Methods: Four hundred thirteen out of 461 psychiatrists attended two 1âday educational programs based on the treatment guidelines for schizophrenia and major depressive disorder from October 2016 to March 2018. We measured the participantsâ clinical knowledge of the treatment guidelines using selfâcompleted questionnaires administered before and after the program to assess the effectiveness of the programs for improving knowledge. We also examined the relation between the participantsâ demographics and their clinical knowledge scores.
Results: The clinical knowledge scores for both guidelines were significantly improved after the program. There was no correlation between clinical knowledge and participant demographics for the program on schizophrenia; however, a weak positive correlation was found between clinical knowledge and the years of professional experience for the program on major depressive disorder.
Conclusion: Our results provide evidence that educational programs on the clinical practices recommended in guidelines for schizophrenia and major depressive disorder might effectively improve participantsâ clinical knowledge of the guidelines. These data are encouraging to facilitate the standardization of clinical practices for psychiatric disorders
The Hyper Suprime-Cam SSP survey: Overview and survey design
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400âdeg2 in five broad bands (grizy), with a 5âÏ point-source depth of r â 26. The Deep layer covers a total of 26âdeg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5âdeg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey
Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000â14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries
Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed
data for children (aged 0â14 years) and adults (aged 15â99 years) diagnosed with a haematological malignancy
during 2000â14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and
morphology, in young patients (aged 0â24 years).
Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3
that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0â14 years),
adolescents (15â19 years), and young adults (20â24 years). We categorised leukaemia subtypes according to the
International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases
for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs,
using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by
country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age
survival estimates were standardised to the marginal distribution of young people with leukaemia included in the
analysis.
Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and
20272 (12·3%) young adults. In 2010â14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients)
and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and
young adults for all leukaemias combined during 2010â14 varied widely, ranging from 46% in Mexico to more than
85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better
age-standardised survival (from 43% in Ecuador to â„80% in parts of Europe, North America, Oceania, and Asia) than
those with acute myeloid leukaemia (from 32% in Peru to â„70% in most high-income countries in Europe,
North America, and Oceania). Throughout 2000â14, survival from all leukaemias combined remained consistently
higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young
adults in most countries.
Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children,
adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower
survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators
of the quality of cancer management in this age group.peer-reviewe
A CASE OF ISOLATED DISSECTING ANEURYSM OF SUPERIOR MESENTERIC ARTERY SUCCESSFULLY TREATED BY ENDOVASCULAR STENT DEPLOYMENT AND COIL EMBOLIZATION
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