250 research outputs found
News From The Gamma Cephei Planetary System
The Gamma Cephei planetary system is one of the most interesting systems due
to several reasons: 1.) it is the first planet candidate detected by precise
radial velocity (RV) measurements that was discussed in the literature
(Campbell et al. 1988); 2.) it is a tight binary system with a ~ 20AU; and 3.)
the planet host star is an evolved K-type star. In Hatzes et al. (2003) we
confirmed the presence of the planetary companion with a minimum mass of 1.7
M_Jup at 2 AU. In this paper we present additional eight years of precise RV
data from the Harlan J. Smith 2.7 m Telescope and its Tull Coude spectrograph
at McDonald Observatory. The 900 d signal, that is interpreted as the presence
of the giant planetary companion, is strongly confirmed by adding the new data.
We present an updated orbital solution for the planet, which shows that the
planet is slightly more massive and the orbit more circular than previous
results have suggested. An intensive high-cadence week of RV observations in
2007 revealed that Gamma Cep A is a multi-periodic pulsator. We discuss this
issue within the context of searching for additional planets in this system.Comment: Part of PlanetsbeyondMS/2010 proceedings
http://arxiv.org/html/1011.660
Pre- and postoperative headache in patients with meningioma
Background
Meningiomas are generally slowly growing intracranial tumors. They are often incidentally diagnosed, given that symptoms may be absent even in cases of an enormous tumor size. Headache is a frequent but not consistent symptom. Therefore, we examined the association between structural, biochemical and histochemical tumor parameters with preoperative as well as postoperative occurrence of headache.
Methods
In our study, we prospectively investigated 69 consecutive patients enrolled for meningioma neurosurgery. Anatomical, histological and biochemical parameters were acquired, and headache parameters were registered from the clinical report and from a questionnaire filled by the patients before neurosurgery. The headache was re-evaluated one year after neurosurgery. The study was designed to exploratively investigate whether there is an association of acquired clinical and biological parameters with the occurrence of preoperative and postoperative headache.
Results
Edema diameter and the proliferation marker MIB-1 were negatively associated with the incidence and intensity of preoperative headache, while the content of prostaglandin E2 in the tumor tissue was positively associated with preoperative headache intensity. Headache was more prevalent when the meningioma was located in the area supplied by the ophthalmic trigeminal branch. Compared to preoperative headache levels, an overall reduction was observed one year postoperative, and patients with a larger tumor had a higher headache remission. In parietal and occipital meningiomas and in those with a larger edema, the percentage of the headache remission rate was higher compared to other locations or smaller edema. Multivariable analyses showed an involvement of substance P and prostaglandin E2 in preoperative headache.
Conclusions
The study demonstrates new associations between meningiomas and headache. The postoperative headache outcome in the presented patient sample is encouraging for the performed neurosurgical intervention. These results should be tested in a prospective study that incorporates all patients with meningiomas
RACE: Remote Analysis Computation for gene Expression data
The Remote Analysis Computation for gene Expression data (RACE) suite is a collection of bioinformatics web tools designed for the analysis of DNA microarray data. RACE performs probe-level data preprocessing, extensive quality checks, data visualization and data normalization for Affymetrix GeneChips. In addition, it offers differential expression analysis on normalized expression levels from any array platform. RACE estimates the false discovery rates of lists of potentially regulated genes and provides a Gene Ontology-term analysis tool for GeneChip data to support the biological interpretation and annotation of results. The analysis is fully automated but can be customized by flexible parameter settings. To offer a convenient starting point for subsequent analyses, and to provide maximum transparency, the R scripts used to generate the results can be downloaded along with the output files. RACE is freely available for use at
Safe and Optimal Techniques Enabling Recovery, Integrity, and Assurance
There is a trend in the aviation industry to go from federated to integrated computing systems. Combining a number of traditional stand-alone federated systems into an integrated common platform (called Integrated Modular Avionics, IMA) has the benefit of increased power efficiency, reduced support hardware, and reduced cabling. However, changing from federated to integrated has a significant impact on the system architecture and hence the process of how avionic systems are to be analyzed. Traditional approaches to safety analysis become inefficient when functional boundaries can no longer be assumed for failure independence and fault isolation. In this report, we describe a tool that we developed to accelerate the safety engineer's ability to perform safety analysis of IMA systems through modeling, as well as optimize the system engineer's ability to develop a system through architecture synthesis. This work was the result of a three-year research effort called SOTERIA (Safe and Optimal Techniques Enabling Recovery, Integrity, and Assurance). We developed a compositional modeling language that supports rapid development, modification, and evaluation of architectures. The modeling language is structured such that the end-user defines a library of components with information on component reliability, connectivity, and fault propagation logic. The system model is built by instantiating the components from the library, connecting the components, and identifying the top-level faults of interest. Our tool is compositional in that the end-user only needs to define safety aspects at the component level. The tool takes the model and automatically synthesizes both the qualitative and quantitative safety analyses. We go further by allowing users to describe system information such as components to use in an architecture and their connection compatibility and automatically synthesize an architecture that meets the top-level probability target adhering to end-user specified constraints. This capability allows users to rapidly explore a design space.
Decreto & Autoritate Magnifici ICtorum Ordinis ... Fiduciam Magistratus ex L. 32. ff. de Iniur. vel: Den ungerechten Obrigkeitlichen Ambts-Trotz: Sub Praesidio Dn. Georgii Michaelis Heberi ... delineat Johann Gottfried Bütner, Lauchâ-Thuringus ...
HD-TEG: Effizienzsteigerungspotential bei Nutzfahrzeugen durch den Einsatz eines neuartigen Abwärmenutzungssystems (Thermoelektrik)
In diesem Projekt wurde die Effizienzsteigerung von modernen schweren
Nutzfahrzeugen durch den Einsatz eines neuartigen Abwärmenutzungssystems
demonstriert. Dabei wurde erstmalig ein nutzfahrzeugspezifisches System basierend auf
der Thermoelektrik mit Hilfe eines gesamtheitlichen Entwicklungsansatzes entwickelt
und das Potential dieser Technologie für heutige und zukünftige Nutzfahrzeuge
dargestellt. Als Referenzfahrzeug diente ein innovatives Serien-Nutzfahrzeug mit
Erdgasmotor, welches als eine Schlüsseltechnologie für den zukünftigen
emissionsärmeren Straßengüterverkehr im Nah- sowie im Fernbereich gilt.
Projektschwerpunkte waren gleichermaßen die Effizienzsteigerung des thermoelektrischen Systems und des Fahrzeuges sowie die Kostensenkung des Systems durch
Verwendung von seriennahen Aufbautechnologien und Fertigungsverfahren. Die
Systemkosten von Abwärmenutzungssystemen im Nutzfahrzeug müssen sich
anwendungsspezifisch in möglichst kurzer Nutzungszeit im Realbetrieb amortisieren.
Dazu wurde eine Bauweise des TEG gewählt, die eine hohe Energieausbeute bei
gleichzeitig geringem Gewicht verspricht und somit Vorteile sowohl unter
Realfahrbedingungen als auch in relevanten Fahrzyklen bietet. Eine neuartige
ganzheitliche Auslegungsmethode bietet das Potential, thermoelektrische Systeme in
Zukunft deutlich effizienter auslegen zu können. Hierbei wurden neben der
Systemauslegung erstmals auch alle Wechselwirkungen mit dem Nutzfahrzeug
betrachtet und quantifiziert. Die Umsetzung dieser Ansätze wurden in mehreren
Funktionsmustern dargestellt. Durch die enge Zusammenarbeit der Projektpartner,
konnte das Wissen und die umfangreiche Erfahrung beider in das Projekt einfließen, um
der Technologie im Nutzfahrzeug zum Durchbruch zu verhelfen.
Als Ergebnis konnte erstmalig ein Abwärmenutzungssystem in Form eines
Thermoelektrischen Generators für ein innovatives Erdgasnutzfahrzeug wirtschaftlich
ausgelegt werden. Die berechnete Amortisation wurde zumeist in einer Zeit von kleiner
als zwei Jahren, unter Annahme der Serienentwicklung des Systems, erzielt. Die
Kraftstoffreduktion liegt bei bis zu 2,5 %, das entspricht rund 1 kg/100 km Kraftstoff.
Zukünftiges Potential liegt bei weiteren 1,2 Prozentpunkten. Bei einer Hardwarerealisierung wurde am Funktionsmuster über 2,5 kW elektrische Leistung gemessen
Hidden Subluminous sd/wd among the FAUST UV sources toward OPHIUCHUS
A UV image in the direction of Ophiuchus, obtained with the FAUST instrument
is analysed. Suitable candidates as unrecognized subluminous stars are selected
comparing the observed UV flux to the predicted one. The uv-excess objects were
observed at the 1.0 m Wise telescope. This method yields to the detection of
eight broad Balmer lines objects. Six are classified as sds and two wds,
comparing the Hbeta line profile with that of stellar model atmospheres.Comment: 2 pages, including 2 figures. To appear in the Proceedings of the
13th European Workshop on White Dwarfs. NATO Science Series II, Kluwer
Academic Publishe
Oxidative stress and inflammatory markers are associated with depression and nicotine dependence
AbstractTo determine if oxidative stress and inflammation are linked with major depressive disorder, nicotine dependence and both disorders combined. This study comprised 150 smokers and 191 never smokers. The instruments were: a socio-demographic questionnaire, diagnoses of mood disorder and nicotine dependence according to DSM-IV, (SCID-IV), and the Alcohol, Smoking and Substance Involvement Screening Test. Laboratory assessments included: nitric oxide metabolites (NOx), lipid hydroperoxides, malondialdehyde (MDA), total reactive antioxidant potential (TRAP), advanced oxidation protein products (AOPP), fibrinogen concentrations, homocysteine, erythrocytes sedimentation rate (ESR) and high-sensitivity C-reactive protein (hs-CRP) were assayed from blood specimens. Statistically significant differences were found among depressed smokers who had more severe depressive symptoms, a higher risk of alcohol consumption, more suicide attempts, and more disability for work than non-depressed never smokers. Depressed smokers had significantly higher levels of NOx, fibrinogen, hs-CRP, AOPP, ESR and lower levels of TRAP compared to non-depressed never smokers. Depressed smokers had significant levels of oxidative stress and inflammatory biomarkers after adjusting for gender, age, years of education, disability for work, and laboratory measures. The levels of NOx, lipid hydroperoxides, AOPP, and fibrinogen were substantially higher, whereas levels of TRAP were lower in depressed smokers compared to non-depressed never smokers. (1) Depressed smokers exhibited altered concentrations of NOx, lipid hydroperoxides, AOPP, TRAP, and fibrinogen. (2) Depressed smokers were more unable to work, showed more severe depressive symptoms and attempted suicide more frequently
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