128 research outputs found
The variable mass loss of the AGB star WX Psc as traced by the CO J=1-0 through 7-6 lines and the dust emission
Low and intermediate mass stars lose a significant fraction of their mass
through a dust-driven wind during the Asymptotic Giant Branch (AGB) phase.
Recent studies show that winds from late-type stars are far from being smooth.
Mass-loss variations occur on different time scales, from years to tens of
thousands of years. The variations appear to be particularly prominent towards
the end of the AGB evolution. The occurrence, amplitude and time scale of these
variations are still not well understood.
The goal of our study is to gain insight into the structure of the
circumstellar envelope (CSE) of WX Psc and map the possible variability of the
late-AGB mass-loss phenomenon.
We have performed an in-depth analysis of the extreme infrared AGB star WX
Psc by modeling (1) the CO J=1-0 through 7-6 rotational line profiles and the
full spectral energy distribution (SED) ranging from 0.7 to 1300 micron. We
hence are able to trace a geometrically extended region of the CSE.
Both mass-loss diagnostics bear evidence of the occurrence of mass-loss
modulations during the last ~2000 yr. In particular, WX Psc went through a high
mass-loss phase (Mdot~5e-5 Msun/yr) some 800 yr ago. This phase lasted about
600 yr and was followed by a long period of low mass loss (Mdot~5e-8 Msun/yr).
The present day mass-loss rate is estimated to be ~6e-6 Msun/yr.
The AGB star WX Psc has undergone strong mass-loss rate variability on a time
scale of several hundred years during the last few thousand years. These
variations are traced in the strength and profile of the CO rotational lines
and in the SED. We have consistently simulated the behaviour of both tracers
using radiative transfer codes that allow for non-constant mass-loss rates.Comment: 12 pages, accepted for publication in A&
Factors Influencing the Green House Gas Footprint of US Dairy Farms
Environmental Economics and Policy, Livestock Production/Industries,
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Casting of Gold Nanoparticles with High Aspect Ratios inside DNA Molds
DNA nanostructures provide a powerful platform for the programmable assembly of nanomaterials. Here this approach is extended to synthesize rod-like gold nanoparticles in a full DNA controlled manner. The approach is based on DNA molds containing elongated cavities. Gold is deposited inside the molds using a seeded-growth procedure. By carefully exploring the growth parameters it is shown that gold nanostructures with aspect ratios of up to 7 can be grown from single seeds. The highly anisotropic growth is in this case controlled only by the rather soft and porous DNA walls. The optimized seeded growth procedure provides a robust and simple routine to achieve continuous gold nanostructures using DNA templating
Fibrates for the treatment of cholestatic itch (FITCH): study protocol for a randomized controlled trial
BACKGROUND: Pruritus (itch) is a frequent, burdensome and difficult-to-treat symptom in patients with cholestasis. Fibrates are currently under investigation for the treatment of primary biliary cholangitis in patients with a suboptimal response to ursodeoxycholic acid. Moreover, there is empirical evidence for a possible antipruritic effect. We aim to prove this in a randomized controlled trial, including patients with cholestatic liver diseases other than primary biliary cholangitis that are accompanied by pruritus. METHODS: A multicenter investigator-initiated, double-blind, randomized placebo-controlled trial to evaluate the effect of bezafibrate on cholestatic pruritus in 84 adult patients with primary biliary cholangitis or primary/secondary sclerosing cholangitis. Primary outcome is the proportion of patients with a reduction of itch intensity of 50% or more (measured on a Visual Analog Scale) after 21 days of treatment with bezafibrate 400 mg qid or placebo. Secondary outcomes include the effect of bezafibrate on a five-dimensional itch score, liver disease-specific quality of life, serum liver tests and autotaxin activity. Safety will be evaluated through serum parameters for kidney function and rhabdomyolysis as well as precise recording of (serious) adverse events. We provide a schematic overview of the study protocol and describe the methods used to recruit and randomize patients, collect and handle data and perform statistical analyses. DISCUSSION: Given its favorable safety profile and anticholestatic properties, bezafibrate may become the new first-line treatment option for treating cholestatic pruritus
BEFKI GC-K: eine Kurzskala zur Messung kristalliner Intelligenz
"In aktuellen Intelligenzstrukturmodellen gehört kristalline Intelligenz (gc) zu den am besten etablierten Fähigkeitsfaktoren. Dabei spiegelt gc die Einflüsse von Lernen und Akkulturation wider und umfasst somit alles Wissen, das Menschen im Laufe ihres Lebens erwerben und zum Problemlösen einsetzen. In diesem Beitrag beschreiben wir die Entwicklung einer Kurzskala zur Messung kristalliner Intelligenz mit fünfminütiger Bearbeitungszeit, die auf deklarativen Wissensfragen aus den Natur-, Geistes- und Sozialwissenschaften beruht. Aus einem umfangreichen Itempool wurde ein 32 Fragen umfassender Wissenstest zusammengestellt und einer bundesweit repräsentativen Stichprobe von 1.134 Erwachsenen vorgelegt. Anhand psychometrischer Kennwerte und der Beziehungen zu Kovariaten erfolgte eine Auswahl von 12 Items für die Kurzskala. Ein eindimensionales Messmodell für diese Itemauswahl wies eine gute Passung und eine hohe Reliabilität des latenten Faktors auf. In der Zielpopulation der erwachsenen deutschen Bevölkerung wurden keine substanziellen Boden- oder Deckeneffekte beobachtet. Übereinstimmend mit der Langversion zeigten sich für die Kurzskala hohe Beziehungen zum Bildungsabschluss (ISCED-97) und sozioökonomischen Status (ISEI) sowie erwartungskonforme Korrelationen mit selbstberichtetem Wissen und den fünf Hauptdimensionen der Persönlichkeit (Big Five). Die Kurzskala ermöglicht folglich eine effiziente, reliable und valide Erfassung kristalliner Intelligenz im Rahmen der Umfrageforschung." (Autorenreferat)"Crystallized intelligence (gc) is a well-established cognitive ability factor that has been conceptualized as reflecting influences of learning, education, and acculturation. In this article, we describe the development of a short knowledge scale for the meas¬urement of gc in five minutes administration time using declarative knowledge items from the sciences, the humanities, and civics. Based on a large item pool we compiled a 32-item knowledge test that was subsequently presented to a nationally representative sample of 1,134 German adults. In the next step, this data were used to derive a short 12-item knowledge scale. A unidimensional measurement model had satisfactory model fit and showed high reliability of the latent factor. There were no substantial floor or ceiling effects in the adult German population. Similar to the full scale, the short scale correlated highly positively with education (ISCED-97) and socio-economic status (ISEI) and was meaningfully related to self-reported knowledge and the Big Five personality traits. Therefore, the short knowledge scale allows for an efficient and valid measurement of crystallized intelligence in survey research." (author's abstract
Ageing phenomena without detailed balance: the contact process
The long-time dynamics of the 1D contact process suddenly brought out of an
uncorrelated initial state is studied through a light-cone transfer-matrix
renormalisation group approach. At criticality, the system undergoes ageing
which is characterised through the dynamical scaling of the two-times
autocorrelation and autoresponse functions. The observed non-equality of the
ageing exponents a and b excludes the possibility of a finite
fluctuation-dissipation ratio in the ageing regime. The scaling form of the
critical autoresponse function is in agreement with the prediction of local
scale-invariance.Comment: 20 pages, 15 figures, Latex2e with IOP macro
The INF Treaty of 1987
Der von Ronald Reagan und Michail Gorbatschow am 8. Dezember 1987 unterzeichnete »Intermediate-Range Nuclear Forces Treaty«, kurz INF-Vertrag, stellte einen Meilenstein der nuklearen Abrüstungsverhandlungen zwischen den Vereinigten Staaten von Amerika und der Sowjetunion dar. Im Jahr 2019 wurde er von Russland und den USA gekündigt. Der englischsprachige Band untersucht die Vorgeschichte des Abkommens, dessen Implementierung und Folgen sowohl in den beiden Supermächten als auch in den mit ihnen verbündeten Staaten. Er ist damit die erste umfassende Darstellung eines der wichtigsten Abrüstungsabkommen der jüngsten Zeit
Screening for Domestic Violence Among Adult Women in the United States
BACKGROUND: Domestic violence is a problem frequently encountered in health care settings and a risk factor for physical and mental health problems. OBJECTIVE: To provide nationally representative estimates of rates of domestic violence screening among women, to identify predictors of screening, and to describe settings where women are screened. DESIGN AND PARTICIPANTS: We examined 4,821 women over the age of 18 from the second wave of Healthcare for Communities, a nationally representative household telephone survey conducted in 2000–2001. MEASUREMENTS: Self-reports concerning whether the respondent was ever asked about domestic or family violence by any health care provider. RESULTS: Only 7% (95% CI, 6%–8%) of women reported they were ever asked about domestic violence or family violence by a health care professional. Of women who were asked about abuse, nearly half (46%) were asked in a primary care setting, and 24% were asked in a specialty mental health setting. Women with risk factors for domestic violence were more likely to report being asked about it by a health care professional, but rates were still low. CONCLUSIONS: Self-reported rates of screening for domestic violence are low even among women at higher risk for abuse. These findings reinforce the importance of developing training and raising awareness of domestic violence and its health implications. This is especially true in primary care and mental health specialty settings
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