1,000 research outputs found
A purely geometric distance to the binary star Atlas, a member of the Pleiades
We present radial velocity and new interferometric measurements of the double
star Atlas, which permit, with the addition of published interferometric data,
to precisely derive the orbital parameters of the binary system and the masses
of the components. The derived semi-major axis, compared with its measured
angular size, allows to determine a distance to Atlas of 132+-4 pc in a purely
geometrical way. Under the assumption that the location of Atlas is
representative of the average distance of the cluster, we confirm the distance
value generally obtained through main sequence fitting, in contradiction with
the early Hipparcos result (118.3+-3.5 pc).Comment: 5 pages, 3 figures, accepted for publication in A&A Letter
Observations of the biological communities at Bolsa Chica artificial reef
Bolsa Chica Artificial Reef (BCAR) was constructed in
November 1986 with 10,400 tons of concrete rubble and
eight concrete and steel barges. Prior to any additional
augmentation of BCAR, the u.s. Army Corps of Engineers
and the California Coastal Commission required the
California Department of Fish and Game (CDFG) to survey
the bioloqical communities on and around BCAR.
In April 1992, qualitative surveys of the biological
communities were conducted on one of the eight modules at
BCAR and at a nearby sand-only site. One of the modules,
Module D, located in 90 feet of water (MLLW), was
surveyed for fish, macroinvertebrates, and turf community
organisms (small plants and sessile animals). Twelve
species of fish were observed, including kelp bass
(Paralabrax clathratus) and barred sand bass (P.
nebulifer). Eight macroinvertebrate species were
observed, rock scallops (Crassedoma giganteum) being the
most abundant. The turf community was comprised of
thirteen invertebrate taxa, among which erect ectoprocts
(Bugula spp.) were the most numerous. Two species of
foliose red algae (Rhodymenia pacifica and Anisocladella
pacifica) were also observed.
The reef has reached an advanced stage of successional
development with fish and invertebrate communities
diverse and well established. However, due,.to its depth
and the turbidity of surrounding waters, this reef is not
likely to ever support a diverse algal community.
The diversity and abundance of fish and
macroinvertebrates were, as to be expected, much lower in
the nearby sand-only site. Only two species of fish and
seven macroinvertebrate species were observed. Of these,
only the sea pen, Stylatula elongata, was common.
Overall, when compared to nearby sand-only habitats,
Bolsa Chica Artificial Reef appears to contribute
substantially to the local biological productivity. In
addition, the concrete rubble used in BCAR' s construction
appears to be performing as well as the quarry rock used
in all of CDFG's experimental reefs. (Document pdf contains 22 pages
Demographic characteristics of patients with extrapulmonary tuberculosis in Germany
The aim of the present study was to determine the demographics of patients with extrapulmonary tuberculosis in Germany. Data on 26,302 tuberculosis cases from a national survey carried out during the period 1996-2000 were analysed. The crude proportion of tuberculosis patients with extrapulmonary manifestations was 21.6%. Extrapulmonary tuberculosis was most likely among females, children aged <15 yrs and persons originating from Africa and Asia. Females tended to be more likely to have any form of extrapulmonary tuberculosis than males, except pleural tuberculosis. The strength of this association was strongest in the age range 25-64 yrs and less pronounced amongst the oldest patients. Children were particularly prone to the development of lymphatic and meningeal tuberculosis, whereas the likelihood of genitourinary tuberculosis increased with increasing age. Asian and African patients were generally more likely than persons from other areas to have lymphatic, osteoarticular, meningeal and miliary tuberculosis. The analysis shows important differences, by age, sex and origin, in the likelihood of a tuberculosis patient presenting with extrapulmonary tuberculosis. Since the relative contribution of the foreign-born to tuberculosis in low-prevalence countries is rising, extrapulmonary tuberculosis must be taken into account more often in the differential diagnostic work-up of these patients, particularly among those originating from Asia and Africa
Recommended from our members
Samuel L. Clemens, Journalist
The purposes of this thesis are two-fold-: 1) in light of the information which is now available, to record accurately the events of the long newspaper career of Samuel L. Clemens; and, 2) to attempt to assess the influence of his journalistic experiences on him as a man, as an observer of humanity, as a reporter fulfilling his assignments, as a developing artist, and as a future author of books
What does your neighbourhood say about you? : a study of life expectancy in 1.3 million Swiss neighbourhoods
BACKGROUND: Switzerland had the highest life expectancy at 82.8 years among the Organisation for Economic Co-operation and Development (OECD) countries in 2011. Geographical variation of life expectancy and its relation to the socioeconomic position of neighbourhoods are, however, not well understood.
METHODS: We analysed the Swiss National Cohort, which linked the 2000 census with mortality records 2000-2008 to estimate life expectancy across neighbourhoods. A neighbourhood index of socioeconomic position (SEP) based on the median rent, education and occupation of household heads and crowding was calculated for 1.3 million overlapping neighbourhoods of 50 households. We used skew-normal regression models, including the index and additionally marital status, education, nationality, religion and occupation to calculate crude and adjusted estimates of life expectancy at age 30 years.
RESULTS: Based on over 4.5 million individuals and over 400,000 deaths, estimates of life expectancy at age 30 in neighbourhoods ranged from 46.9 to 54.2 years in men and from 53.5 to 57.2 years in women. The correlation between life expectancy and neighbourhood SEP was strong (r=0.95 in men and r=0.94 women, both p values <0.0001). In a comparison of the lowest with the highest percentile of neighbourhood SEP, the crude difference in life expectancy from skew-normal regression was 4.5 years in men and 2.5 years in women. The corresponding adjusted differences were 2.8 and 1.9 years, respectively (all p values <0.0001).
CONCLUSIONS: Although life expectancy is high in Switzerland, there is substantial geographical variation and life expectancy is strongly associated with the social standing of neighbourhoods
The Swiss Childhood Cancer Registry: rationale, organisation and results for the years 2001-2005.
Childhood cancer is a rare but severe disease. Therefore central registration of all cases is essential for surveillance and management. This paper describes the methodology and basic results of the Swiss Childhood Cancer Registry (SCCR).
The SCCR was established in 1976, originally as a national hospital-based registry of childhood malignancies. All 9 paediatric oncology-haematology clinics in Switzerland provide baseline and follow-up information on all children diagnosed with cancer. These data are registered centrally and diagnoses are coded according to the International Classification of Childhood Cancer.
From 2001-2005, 887 cases of childhood cancer in Swiss residents under the age of 15 years were registered in the SCCR. Of these, 281 (31.7%) were leukaemias, 223 (24.0%) were CNS tumours, and 116 (13.1%) were lymphomas. The age-standardised annual incidence per 1 Million person-years (age below 15 years; world standardisation) was 154.0 (95% CI 143.7-164.3; N = 887). The incidence was higher for boys (170.2, 155.0-185.4; N = 501) than for girls (136.9, 123.0-150.8; N = 386).
The close collaboration between all paediatric oncologists-haematologists in Switzerland and a university department allowed the creation of a national population-based cancer registry with detailed clinical information. The SCCR produces cancer type specific incidence and survival estimates and allows the development of nested research projects on childhood cancer aetiology, management and outcome, both on a national and on an international level
A systematic review of the survival and complication rates of zirconia-ceramic and metal-ceramic single crowns
Objectives: The aim of the present systematic review was to analyze the survival and complication rates of zirconia-based and metal-ceramic implant-supported single crowns (SCs). Materials and Methods: An electronic MEDLINE search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective cohort and retrospective case series on implant-supported SCs with a mean follow-up time of at least 3 years. Patients had to have been clinically examined at the follow-up visit. Assessment of the identified studies and data extraction was performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. Results: The search provided 5,263 titles and 455 abstracts, full-text analysis was performed for 240 articles, resulting in 35 included studies on implant-supported crowns. Meta-analysis revealed an estimated 5-year survival rate of 98.3% (95% CI: 96.8–99.1) for metal-ceramic implant supported SCs (n = 4,363) compared to 97.6% (95% CI: 94.3–99.0) for zirconia implant supported SCs (n = 912). About 86.7% (95% CI: 80.7–91.0) of the metal-ceramic SCs (n = 1,300) experienced no biological/technical complications over the entire observation period. The corresponding rate for zirconia SCs (n = 76) was 83.8% (95% CI: 61.6–93.8). The biologic outcomes of the two types of crowns were similar; yet, zirconia SCs exhibited less aesthetic complications than metal-ceramics. The 5-year incidence of chipping of the veneering ceramic was similar between the material groups (2.9% metal-ceramic, 2.8% zirconia-ceramic). Significantly (p = 0.001), more zirconia-ceramic implant SCs failed due to material fractures (2.1% vs. 0.2% metal-ceramic implant SCs). No studies on newer types of monolithic zirconia SCs fulfilled the simple inclusion criteria of 3 years follow-up time and clinical examination of the present systematic review. Conclusion: Zirconia-ceramic implant-supported SCs are a valid treatment alternative to metal-ceramic SCs, with similar incidence of biological complications and less aesthetic problems. The amount of ceramic chipping was similar between the material groups; yet, significantly more zirconia crowns failed due to material fractures
Comparing methods for estimating patient‐specific treatment effects in individual patient data meta‐analysis
Meta-analysis of individual patient data (IPD) is increasingly used to synthesize data from multiple trials. IPD meta-analysis offers several advantages over
meta-analyzing aggregate data, including the capacity to individualize treatment
recommendations. Trials usually collect information on many patient characteristics. Some of these covariates may strongly interact with treatment (and thus
be associated with treatment effect modification) while others may have little
effect. It is currently unclear whether a systematic approach to the selection of
treatment-covariate interactions in an IPD meta-analysis can lead to better estimates of patient-specific treatment effects. We aimed to answer this question
by comparing in simulations the standard approach to IPD meta-analysis (no
variable selection, all treatment-covariate interactions included in the model)
with six alternative methods: stepwise regression, and five regression methods that perform shrinkage on treatment-covariate interactions, that is, least
absolute shrinkage and selection operator (LASSO), ridge, adaptive LASSO,
Bayesian LASSO, and stochastic search variable selection. Exploring a range
of scenarios, we found that shrinkage methods performed well for both continuous and dichotomous outcomes, for a variety of settings. In most scenarios, these methods gave lower mean squared error of the patient-specific
treatment effect as compared with the standard approach and stepwise regression. We illustrate the application of these methods in two datasets from
cardiology and psychiatry. We recommend that future IPD meta-analysis that
aim to estimate patient-specific treatment effects using multiple effect modifiers should use shrinkage methods, whereas stepwise regression should be
avoided
- …