699 research outputs found
Optical constants of refractory oxides at high temperatures
Many cosmic dust species, among them refractory oxides, form at temperatures
higher than 300 K. Nevertheless, most astrophysical studies are based on the
room-temperature optical constants of solids, such as corundum and spinel. A
more realistic approach is needed for these materials, especially in the
context of modeling late-type stars. We aimed at deriving sets of optical
constants of selected, astrophysically relevant oxide dust species with high
melting points. A high-temperature-high-pressure-cell and a Fourier-transform
spectrometer were used to measure reflectance spectra of polished samples. For
corundum (alpha-AlO), spinel (MgAlO), and alpha-quartz
(SiO), temperature-dependent optical constants were measured from 300 K up
to more than 900 K. Small particle spectra were also calculated from these
data. All three examined oxides show a significant temperature dependence of
their mid-IR bands. For the case of corundum, we find that the 13m
emission feature - seen in the IR spectra of many AGB stars - can very well be
assigned to this mineral species. The best fit of the feature is achieved with
oblate corundum grains at mean temperatures around 550 K. Spinel remains a
viable carrier of the 13m feature as well, but only for T < 300 K and
nearly spherical grain shapes. Under such circumstances, spinel grains may also
account for the 31.8m band that is frequently seen in sources of the
13m feature and which has not yet been identified with certainty.Comment: Astronomy & Astrophysics, accepted, 26 February 2013. Article with 18
pages and 15 figure
PhoneGuide: Museum Guidance Supported by On-Device Object Recognition on Mobile Phones
We present PhoneGuide – an enhanced museum guidance approach that uses camera-equipped mobile phones and on-device object recognition. Our main technical achievement is a simple and light-weight object recognition approach that is realized with single-layer perceptron neuronal networks. In contrast to related systems which perform computational intensive image processing tasks on remote servers, our intention is to carry out all computations directly on the phone. This ensures little or even no network traffic and consequently decreases cost for online times. Our laboratory experiments and field surveys have shown that photographed museum exhibits can be recognized with a probability of over 90%. We have evaluated different feature sets to optimize the recognition rate and performance. Our experiments revealed that normalized color features are most effective for our method. Choosing such a feature set allows recognizing an object below one second on up-to-date phones. The amount of data that is required for differentiating 50 objects from multiple perspectives is less than 6KBytes
Biologic TNF inhibiting agents for treatment of inflammatory rheumatic diseases: Dosing patterns and related costs in Switzerland from a payers perspective
Background: To obtain detailed real-life data on costs and dosing patterns in the utilisation of the TNF inhibitors adalimumab, etanercept, and infliximab in patients treated in Switzerland. Methods: Administrative claims processed by a major Swiss health insurer between 2005 and 2008 were analysed. Patients with inflammatory rheumatic diseases (IRDs) with at least one prescription for adalimumab, etanercept, or infliximab were identified. All-cause and disease-specific costs, as well as daily costs of treatment, were calculated. Dosing patterns and discontinuation rates were analysed. Results: A total of 555 IRD patients were identified. All-cause costs during the 12 months after the index event were 20,555CHF in the etanercept group, 24,152CHF in the adalimumab group, and 27,614CHF in the infliximab group. The most important cost driver was mean TNF inhibitor drug cost, which was 15,613CHF in the etanercept group, 19,166CHF in the adalimumab group, and 21,313CHF in the infliximab group. Discontinuation rates during the first year after the index event were 46.8% in etanercept, 41.3% in adalimumab, and 51.2% in the infliximab group. Rates of dosage increase were 13.3% in the etanercept group, 13.0% in the adalimumab group, and 14.1% in the infliximab group. When time on treatment was considered, daily costs of treatment were similar for etanercept and adalimumab, but were higher for infliximab. Conclusions: Marked differences in costs between subcutaneous and intravenous therapies were observed. Among the three groups of patients defined by TNF inhibitor treatment, costs for the infliximab group were highest during the year after the index event.Helsana Versicherungen A
Linguistic means of representation of the concept "city" in Russian language (on the basis of Russian tourists reviews about China)
Настоящее исследование посвящено анализу языковой репрезентации лингвокультурного концепта «город» в отзывах российских туристов о Китае. Актуальность работы определяется продуктивностью антропоцентрического подхода к описанию языка, усилением внимания и потребностью современного языкознания в исследовании ключевых концептов культуры, к которым относится и описываемый концепт «город», представляющий собой одну из глобальных ментальных единиц в составе русской концептосферы. В ходе исследования применялся метод научного описания, позволивший выявить структуру концепта, описать микроконцепты, его составляющие, - древний город, современный город и город-сад (пляжный город), а также языковые средства, объективирующие данное лингвокультурное образование в жанре отзыва. The present study focuses on the analysis of language representation of linguocultural concept “city” in a review of Russian tourists about China. The relevance of the paper is determined by the productivity of anthropocentric approach to language description, increased attention and the need of modern linguistics in the study of the key concepts of the culture to which relates the described concept “city”, which is one of the global mental units within the Russian sphere of concepts. As part of the study the method of scientific description was used to discover and clarify the concept of structure, describe microconcepts, its components - the ancient city, the modern city and city-garden (beach town) as well as linguistic means, objectifying this linguocultural education in the genre of comment
Near-infrared absorption properties of oxygen-rich stardust analogues: The influence of coloring metal ions
Several astrophysically relevant solid oxides and silicates have extremely
small opacities in the visual and near-infrared in their pure forms. Datasets
for the opacities and for the imaginary part k of their complex indices of
refraction are hardly available in these wavelength ranges. We aimed at
determining k for spinel, rutile, anatase, and olivine, especially in the
near-infrared region. Our measurements were made with impurity-containing,
natural, and synthetic stardust analogs. Two experimental methods were used:
preparing small sections of natural minerals and synthesizing melt droplets
under the electric arc furnace. In both cases, the aborption properties of the
samples were measured by transmission spectroscopy. For spinel (MgAl2O4),
anatase, rutile (both TiO2), and olivine ((Mg,Fe)2SiO4), the optical constants
have been extended to the visual and near-infrared. We highlight that the
individual values of k and the absorption cross section depend strongly on the
content in transition metals like iron. Based on our measurements, we infer
that k values below 10^(-5) are very rare in natural minerals including
stardust grains, if they occur at all. Data for k and the absorption cross
section are important for various physical properties of stardust grains such
as temperature and radiation pressure. With increasing absorption cross section
due to impurities, the equilibrium temperature of small grains in circumstellar
shells increases as well. We discuss why and to what extent this is the case
Biologic TNF inhibiting agents for treatment of rheumatoid arthritis: persistence and dosing patterns in Germany
Objective: To obtain detailed real-world data on persistence and dosing patterns in the utilisation of the TNF inhibitors adalimumab, etanercept, and infliximab in rheumatoid arthritis (RA) patients treated in Germany. Methods: In this retrospective observational study claims data of a major German health insurance fund between 2005 and 2008 were analysed. Patients receiving at least one prescription of adalimumab, etanercept or infliximab were identified and categorised as "TNF inhibitor naive" or "TNF inhibitor continuing". For the calculation of TNF inhibitor persistence a survival analysis with the Kaplan-Meier estimator was used. A Cox regression was used to analyse, if any relevant factors were influencing persistence. Dosage increase rates were analysed for adalimumab, etanercept and infliximab. Sensitivity analyses based on variations in gap length were conducted. Results: A total of 2,201 RA patients were identified. 1,468 of these patients were TNF inhibitor naive patients and 733 were defined as TNF inhibitor continuing patients. There were no significant differences in the treatment persistence rates between adalimumab, etanercept and infliximab for TNF inhibitor naive and continuing patients. The persistence rate after three years was 22.47% for adalimumab, 24.27% for etanercept and 21.49% for infliximab naive patients. For continuing patients, the persistence rate after three years was 32.88% for adalimumab, 30.95% for etanercept, and 33.90% for infliximab, respectively. Gender, medication and Charlson Comorbidities Index did not influence the persistence significantly. Dosage increase occurred in 7.3% adalimumab, 1.4% etanercept, and 17.2% infliximab naive patients and 5.8%, 1.1% and 11.9% respectively in the continuing patients. Conclusions: In this study, there were no significant differences in persistence among adalimumab, etanercept and infliximab treated patients. Consistent with previous research, there was a higher dose escalation for infliximab than for the two subcutaneous treatments, adalimumab or etanercept
PhoneGuide: Museum Guidance Supported by On-Device Object Recognition on Mobile Phones
We present PhoneGuide – an enhanced museum guidance approach that uses camera-equipped mobile phones and on-device object recognition. Our main technical achievement is a simple and light-weight object recognition approach that is realized with single-layer perceptron neuronal networks. In contrast to related systems which perform computational intensive image processing tasks on remote servers, our intention is to carry out all computations directly on the phone. This ensures little or even no network traffic and consequently decreases cost for online times. Our laboratory experiments and field surveys have shown that photographed museum exhibits can be recognized with a probability of over 90%. We have evaluated different feature sets to optimize the recognition rate and performance. Our experiments revealed that normalized color features are most effective for our method. Choosing such a feature set allows recognizing an object below one second on up-to-date phones. The amount of data that is required for differentiating 50 objects from multiple perspectives is less than 6KBytes
Recent Results of Solid-State Spectroscopy
Solid state spectroscopy continues to be an important source of information
on the mineralogical composition and physical properties of dust grains both in
space and on planetary surfaces. With only a few exceptions, artificially
produced or natural terrestrial analog materials, rather than 'real' cosmic
dust grains, are the subject of solid state astrophysics. The Jena laboratory
has provided a large number of data sets characterizing the UV, optical and
infrared properties of such cosmic dust analogs. The present paper highlights
recent developments and results achieved in this context, focussing on
'non-standard conditions' such as very low temperatures, very high temperatures
and very long wavelengths.Comment: 15 pages, 10 figures. Contribution to an IAU Conference "The
Molecular Universe" held in Toledo in June 201
Enabling Mobile Phones To Support Large-Scale Museum Guidance
We present a museum guidance system called PhoneGuide that uses widespread camera equipped mobile phones for on-device object recognition in combination with pervasive tracking. It provides additional location- and object-aware multimedia content to museum visitors, and is scalable to cover a large number of museum objects
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