bluuebunny/crossref_metadata_2025_split huggingface dataset:
On convergence, admissibility and attractors for damped wave equations on squeezed domains
Authors: Carbinatto M. C. , Rybakowski K. P. 
Published: July 2007

Let be an arbitrary non-empty bounded Lipschitz domain in RM RN. Given > 0, squeeze by the factor in the y-direction to obtain the squeezed domain := {(x, y) | (x, y) }. Let and be positive constants. Consider the following semilinear damped wave equation on ,

where is the exterior normal vector field on and G is an appropriate nonlinearity, which ensures that (W) generates a (local) flow ̃ on X := H1() L2(). We show that there is a closed subspace X0 of X and a flow ̃0 on X0 that is the limit flow of the family ̃, > 0. We show that, as 0, the family ̃ converges in some singular sense to ̃ and establish a technical singular asymptotic compactness property. As a corollary, we obtain an upper-semicontinuity result for global attractors of the family ̃, 0, generalizing results obtained previously by Hale and Raugel for domains that are ordinate sets of a positive function.The results obtained here are also applied in our paper On a general Conley index continuation principle for singular perturbation problems to establish a singular Conley index continuation principle for damped wave equations on thin domains.
n–3 Fatty acids,
hypertension and risk of cognitive decline among older adults in the
Atherosclerosis Risk in Communities (ARIC) study
Authors: Beydoun May A , Kaufman Jay S , Sloane Philip D , Heiss Gerardo , Ibrahim Joseph 
Published: July 2007

AbstractObjectiveRecent research indicates that n–3 fatty acids can inhibit cognitive decline,
perhaps differentially by hypertensive status.DesignWe tested these hypotheses in a prospective cohort study (the Atherosclerosis
Risk in Communities). Dietary assessment using a food-frequency
questionnaire and plasma fatty acid exposure by gas chromatography were
completed in 1987–1989 (visit 1), while cognitive assessment with
three screening tools – the Delayed Word Recall Test, the Digit
Symbol Substitution Test of the Wechsler Adult Intelligence
Scale–Revised and the Word Fluency Test (WFT) – was
completed in 1990–1992 (visit 2) and 1996–1998 (visit
4). Regression calibration and simulation extrapolation were used to control
for measurement error in dietary exposures.SettingFour US communities – Forsyth County (North Carolina), Jackson
(Mississippi), suburbs of Minneapolis (Minnesota) and Washington County
(Maryland).SubjectsMen and women aged 50–65 years at visit 1 with complete dietary
data (n = 7814); white men and women in
same age group in the Minnesota field centre with complete plasma fatty acid
data (n = 2251).ResultsFindings indicated that an increase of one standard deviation in dietary
long-chain n–3 fatty acids (%
of energy intake) and balancing long-chain n−3/n–6 decreased the risk of 6-year cognitive decline in
verbal fluency with an odds ratio (95% confidence interval) of 0.79
(0.66–0.95) and 0.81 (0.68–0.96), respectively, among
hypertensives. An interaction with hypertensive status was found for dietary
long-chain n–3 fatty acids (g
day−1) and WFT decline (likelihood ratio test,
P = 0.06). This exposure in plasma
cholesteryl esters was also protective against WFT decline, particularly
among hypertensives (OR = 0.51, P
< 0.05).ConclusionOne implication from our study is that diets rich in fatty acids of marine
origin should be considered for middle-aged hypertensive subjects. To this
end, randomised clinical trials are needed.
Obesity and associated lifestyle behaviours in Iran: findings from the First National Non-communicable Disease Risk Factor Surveillance Survey
Authors: Kelishadi Roya , Alikhani Siamak , Delavari Alireza , Alaedini Farshid , Safaie Afshin , Hojatzadeh Eliyeh 
Published: July 2007

AbstractObjectiveTo assess the national prevalence of overweight and obesity, as well as some associated lifestyle behaviours, for the first time in Iran.Design and SettingsThis population-based study was performed in early 2005 as part of the World Health Organization (WHO) STEPwise approach to non-communicable diseases’ risk factor surveillance. Dietary and physical activity habits were assessed by WHO questionnaires.SubjectsThe study population comprised 89 532 subjects aged over 15 years living in the 28 provinces of Iran.ResultsOverall, 50.4% (n= 45 113) of the participants were male and 64.6% (n= 57 866) were from the urban areas. The national estimates of overweight, obesity and morbid obesity were 28.6%, 10.8% and 3.4%, respectively. Body mass index (BMI) ≥ 25 kg m−2in men, women, urban residents and rural residents were found in 37%, 48%, 46.7% and 35.5%, respectively. Abdominal obesity was present in 43.4% of women, 9.7% of men, 28.5% of the urban residents and 23% of the rural residents. Overweight as well as generalised and abdominal obesity were more prevalent in the 45–64-year age group. Although there was no significant difference in frequency of consumption of the food groups in subjects with different BMI categories, various kinds of physical activities showed a steady decline with increasing BMI.ConclusionsThe findings of the present study provide alarming evidence for health professionals and policy makers about the very high prevalence of generalised and abdominal obesity in Iran. The unhealthy lifestyle habits, notably sedentary lifestyles in our community, are the major contributing factors for this emerging public health problem.
Professor Mirek J. Plavec
Authors: Harmanec Petr , Grygar Jiří , Batten Alan H. , Peters Geraldine J. , Linnell Albert P. , Hubeny Ivan , Guinan Edward F. 
Published: July 2007

AbstractIn keeping with its co-sponsorship by members of both the “close” and “wide” binary star communities, IAU Symposium 240 has been jointly dedicated to the honor of Czech astronomer Mirek J. Plavec and the memory of U.S. astronomer Charles E. Worley.
Overview of Multiple–Aperture Interferometry Binary Star Results from the Southern Hemisphere
Authors: Davis John 
Published: July 2007

AbstractThe first multiple-aperture interferometric study of a binary system, in which the power of combining interferometric and spectroscopic data was demonstrated, was made from the Southern Hemisphere. The observations of α Vir with the Narrabri Stellar Intensity Interferometer (NSII) were combined with spectroscopic and photometric data to yield the mass, radius and luminosity of the primary as well as an accurate distance to the system. The NSII also revealed a number of stars, previously thought to be single, to be binary systems. Several of these systems have subsequently been shown to be spectroscopic binaries.The Sydney University Stellar Interferometer (SUSI) and the European Southern Observatory's Very Large Telescope Interferometer (VLTI) are the two current Southern Hemisphere multiple aperture interferometers. SUSI is being used to determine interferometric orbits for some of the binary systems discovered with the NSII including β Cen and λ Sco and, in combination with spectroscopy, to determine accurate masses for early-type stars and accurate dynamical parallaxes for the systems.The VLTI has operated with three beam-combining instruments, namely VINCI, MIDI and AMBER. The few observations of binary systems that have been made so far are summarised and, while in general they are of a preliminary nature, they demonstrate the potential of the VLTI for binary star studies.One double-lined spectroscopic binary that has been observed with all three Southern Hemisphere instruments is γ2Vel, which has the brightest Wolf-Rayet star in the sky as its secondary. The observations and preliminary results for the masses of the O-type primary and WC8 secondary and for the distance to the system are summarised.
Spectroscopic Binary Candidates for Interferometers
Authors: Fekel Francis C. , Tomkin Jocelyn 
Published: July 2007

AbstractWe present a progress report on a program to improve the orbits of known spectroscopic binaries that are potential targets for ground-based optical interferometers, such as the CHARA array and PTI. The combination of such observations results in three-dimensional orbits that produce very accurate masses (uncertainties of less than 0.5%) as well as orbital parallaxes that are generally more precise than those from Hipparcos. After additional analyses determine other basic parameters of the stars, the components can be compared with theoretical evolutionary tracks. We are currently using three observatories to obtain high-resolution, red-wavelength spectra of 44 systems. Results from four years of observation are highlighted. Interferometric observations of some systems are in progress.
DE CVn: A Bright, Eclipsing Red Dwarf – White Dwarf Binary
Authors: van den Besselaar E. J. M. , Greimel R. , Morales-Rueda L. , Nelemans G. , Thorstensen J. R. , Marsh T. R. , Dhillon V. S. , Robb R. M. , Balam D. D. , Guenther E. W. , Kemp J. , Augusteijn T. , Groot P. J. 
Published: July 2007

AbstractDE CVn is a relatively unstudied eclipsing binary where one of the components is an M dwarf and the other is a white dwarf. Its brightness makes it an ideal system for a detailed study in the context of common-envelope evolution of a detached white dwarf – red dwarf binary with a relatively short orbital period (∼8.7 hours). We present a detailed study of the basic parameters (e.g. orbital period, components' masses and spectral types) for this system from photometric and spectroscopic studies. The eclipses observed during several photometric observing runs were used to derive the ephemeris. We have used spectroscopic data to derive the radial velocity variations of the emission lines and these are used to determine the components' masses and the orbital separation. The secondary component in DE CVn is an M3 main-sequence star and the primary star, which only contributes to the blue continuum, is a cool white dwarf with a temperature of ∼8000 K. From the photometry and spectroscopy together, we have set a limit on the binary inclination. This system is a post-common-envelope system where the progenitor of the present day white dwarf was a low-mass star (M≤2M⊙). The time before DE CVn becomes a semi-detached system is longer than the Hubble time.
The Eclipsing Triple System U Ophiuchi Revisited
Authors: Vaz Luiz Paulo R. , Andersen Johannes , Claret Antônio 
Published: July 2007

AbstractWe have redetermined the absolute dimensions of the mid B-type eclipsing binary U Oph from new light and radial-velocity curves, accounting for both the apsidal motion and the light-time orbit around the third star. The stars in U Oph have masses of 5.27 and 4.74 M⊙(±1.5%) and are located in the middle of the main-sequence band for an an age of ∼50 Myr. U Oph and three other systems (V760 Sco, MU, Cas and DI Her) all have components within 10% of 5M⊙ and ages below 100 Myr; we find significant heavy-element abundance differences between these young nearby stars.
Doppler Imaging of Close Binaries
Authors: Strassmeier Klaus G. 
Published: July 2007

AbstractMany of the interesting spotted stars are in close binaries where one can find almost any rotational period due to the rotational synchronization with the orbital motion. Binaries are thus good laboratories to study the impact of particular astrophysical parameters that nature usually does not make easily observable. On rapidly-rotating stars, we can indirectly resolve the surface by tomographic imaging techniques and map the surface temperature distribution as a proxy of the (predominantly radial) magnetic field. Binaries are not as straightforward to map as single stars and I will show some examples where it was successful and some where it failed. Eclipses may give some clues on the amount of unresolved features in the images. I present one case of a bright giant of 100L⊙ in a close binary with even a deformed surface geometry but otherwise solar-type behavior. One of the basic goals is to learn about the impact of inter-binary magnetic fields on the evolution of its components in general and to eventually provide conclusive constraints for numerical MHD models on the other hand.
Evidence for a Precessing Disk in the Extreme Binary ϵ Aurigae
Authors: Stencel Robert E. 
Published: July 2007

AbstractAmong the longest known eclipse durations and binary periods is that of the star ϵ Aurigae, which exhibits 2-year long eclipses every 27.1 years. Oddly, the nature of the secondary in the system continues to elude ready identification. In 1965, Huang proposed a massive disk as the eclipsing body, and study of the 1984 eclipse led Lissauer and Backman to suggest an embedded B star binary in the disk to maintain it. A collaboration of observers allows me to present recent optical photometry and spectroscopy, near-IR spectroscopy and Spitzer space telescope IRS and MIPS observations of ϵ Aurigae as it approaches its next eclipse. These data argue for current detectability of the embedded binary, and precession of the disk axis, suggesting a radical change is possible for the next mid-eclipse brightening. An international monitoring campaign for the 2009-2011 is being organized, and participation invited via website http://www.du.edu/~rstencel/epsaur.htm.
New Findings Supporting the Presence of Several Distinct Structures of Circumstellar Matter in β Lyræ
Authors: Chadima P. , Harmanec P. , Ak H , Demirçan O. , Yang S. , Koubský P. , Škoda P. , Šlechta M. , Wolf M. , Božić H. , Ruždjak D. , Sudar D. 
Published: July 2007

Abstract(1) 52 photographic and 651 electronic spectra were disentangled using the program KOREL. This led to the detection of a number of weak absorption lines originating in the atmosphere of the accretion disk. So far, the detection of this disk spectrum was only reported for the Si 6347 and 6371 Å doublet. (2) The basic spectrophotometric quantities of 15 absorption lines of the primary were measured and corrected for the orbital light changes in order to eliminate the contribution of the secondary light to the observed continuum level. After the correction, a significant phase dependency of the spectral-line characteristics near the primary eclipse was detected. In all probability, another so far unknown absorption-line spectrum was thus found. This spectrum may be due to additional absorption of light of the primary in one of the jet-like structures and in the spherical gas envelope surrounding the accretion disk. Both these structures are seen projected against the primary during its eclipse.
TheKepler Missionand Eclipsing Binaries
Authors: Koch David , Borucki William , Basri Gibor , Brown Timothy , Caldwell Douglas , Christensen-Dalsgaard Jorgen , Cochran William , DeVore Edna , Dunham Edward , Gautier Thomas N. , Geary John , Gilliland Ronald , Gould Alan , Jenkins Jon , Kondo Yoji , Latham David , Lissauer Jack , Monet David 
Published: July 2007

AbstractTheKepler Missionis a space-based photometric mission with a differential photometric precision of 14 ppm (atV= 12 for a 6.5 hour transit). It is designed to continuously observe a single field of view (FOV) of greater then 100 square degrees in the Cygnus-Lyra region for four or more years. The primary goal of the mission is to monitor more than one-hundred thousand stars for transits of Earth-size and smaller planets in the habitable zone of solar-like stars. In the process, many eclipsing binaries (EB) will also be detected and light curves produced. To enhance and optimize the mission results, the stellar characteristics for all the stars in theKeplerFOV withV< 16 will have been determined prior to launch. As part of the verification process, stars with transit candidates will have radial-velocity follow-up observations performed to determine the component masses and thereby separate eclipses caused by stellar companions from transits caused by planets. The result will be a rich database on EBs. The community will have access to the archive for further analysis, such as, for EB modeling of the high-precision light curves. A guest observer program is also planned to allow for photometric observations of objects not on the target list but within the FOV.
Multiplicity of Herbig Ae/Be Stars
Authors: Thomas Sandrine J. , van der Bliek Nicole S. , Rodgers Bernadette , Doppmann Greg , Bouvier Jérôme 
Published: July 2007

AbstractOne of the most interesting constraints on star formation models comes from the study of multiplicity of young stars as a function of mass. While multiplicity studies of low-mass T Tauri stars have been quite exhaustive, an unbiased and systematic investigation of multiplicity among intermediate-mass Herbig Ae/Be (HAEBE) stars is still lacking. We are therefore conducting a photometric and spectroscopic survey of HAEBE stars to detect companions, establish their physical association with the primary and investigate their properties. The frequency and degree of multiplicity of HAEBE systems will provide new constraints on their formation mechanisms. In this paper we present preliminary results of the high resolution imaging part of the survey, carried out with the adaptive optics system Altair-NIRI on Gemini North. Of 72 stars observed, we find 44 possible binaries or multiples, including at least 25 not previously known.
The Distance to the Pleiades Revisited
Authors: Valls-Gabaud David 
Published: July 2007

AbstractThe parallax of the Pleiades has been mired in controversy ever since the very first astrometric measures in the late 1880s. Over a century later, the measures from the HIPPARCOS catalogue gave results which were inconsistent with the distance inferred from the fitting of the colour-magnitude diagram. We briefly review here the debate and focus on the various attempts made at solving the problem, and especially those using binary stars. The only double-lined eclipsing binary found so far in the Pleiades, HD 23642, provides not only the final answer to the problem but also, through detailed state-of-the-art analyses, the fundamental calibration for binaries in more distant clusters and hence in the Local Group. We discuss some of the various sources of systematic uncertainties that limit, so far, the accuracy of the measured stellar parameters to about 1% and the progress that is required to break this barrier.
Young Binaries as a Test for Pre-Main Sequence Evolutionary Tracks
Authors: Zinnecker Hans 
Published: July 2007

AbstractObservations of young low-mass binaries (t ≲ 107 yr, M ≲ 3 M_⊙) can be used to calibrate pre-Main Sequence (pre-MS) evolutionary tracks. Recent high angular resolution HST/FGS, speckle, and long-baseline interferometry have resolved the astrometric orbits of a few SB2 pre-MS binaries and have provided the individual dynamical masses of their components as well as the system orbital parallaxes. Spectroscopic fits and filter photometry have permitted to determine SpT (temperatures) and a good estimate of the absolute magnitude (bolometric luminosity) of the components, which in turn allows one to place the components on a theoretical HR-diagram. In this way, one can check (a) whether the measured dynamical masses agree with the predicted masses on the tracks and (b) whether both components lie on an isochrone, as they should for a coeval physical pair of stars.With a sufficiently large sample of different masses and ages of resolved SB2 systems, most of the parameter space of pre-MS tracks can be tested, even for very low stellar masses (M < 0.5 M_⊙) and very young ages (< 2 Myr). This is a prerequisite in order to derive the IMF and star formation history in very young clusters and associations.
The Initial–Final Mass Relationship of White Dwarfs in Common Proper Motion Pairs and Open Clusters
Authors: Catalán S. , Ribas I. , Isern J. , García–Berro E. , Prieto C. Allende 
Published: July 2007

AbstractWe have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we report new results obtained from spectroscopic observations of both members of several CPMPs composed of an F, G or K type star and a DA white dwarf.
Culture independent analysis of ileal mucosa reveals a selective increase in invasive Escherichia coli of novel phylogeny relative to depletion of Clostridiales in Crohn's disease involving the ileum
Authors: Baumgart Martin , Dogan Belgin , Rishniw Mark , Weitzman Gil , Bosworth Brian , Yantiss Rhonda , Orsi Renato H , Wiedmann Martin , McDonough Patrick , Kim Sung Guk , Berg Douglas , Schukken Ynte , Scherl Ellen , Simpson Kenneth W 
Published: July 2007

Abstract
Intestinal bacteria are implicated increasingly as a pivotal factor in the development of Crohn's disease, but the specific components of the complex polymicrobial enteric environment driving the inflammatory response are unresolved. This study addresses the role of the ileal mucosa-associated microflora in Crohn's disease. A combination of culture-independent analysis of bacterial diversity (16S rDNA library analysis, quantitative PCR and fluorescence in situ hybridization) and molecular characterization of cultured bacteria was used to examine the ileal mucosa-associated flora of patients with Crohn's disease involving the ileum (13), Crohn's disease restricted to the colon (CCD) (8) and healthy individuals (7). Analysis of 16S rDNA libraries constructed from ileal mucosa yielded nine clades that segregated according to their origin (P&lt;0.0001). 16S rDNA libraries of ileitis mucosa were enriched in sequences for Escherichia coli (P&lt;0.001), but relatively depleted in a subset of Clostridiales (P&lt;0.05). PCR of mucosal DNA was negative for Mycobacterium avium subspecies paratuberculosis, Shigella and Listeria. The number of E. coli in situ correlated with the severity of ileal disease (ρ 0.621, P&lt;0.001) and invasive E. coli was restricted to inflamed mucosa. E. coli strains isolated from the ileum were predominantly novel in phylogeny, displayed pathogen-like behavior in vitro and harbored chromosomal and episomal elements similar to those described in extraintestinal pathogenic E. coli and pathogenic Enterobacteriaceae. These data establish that dysbiosis of the ileal mucosa-associated flora correlates with an ileal Crohn's disease (ICD) phenotype, and raise the possibility that a selective increase in a novel group of invasive E. coli is involved in the etiopathogenesis to Crohn's disease involving the ileum.
Colorful niches of phototrophic microorganisms shaped by vibrations of the water molecule
Authors: Stomp Maayke , Huisman Jef , Stal Lucas J , Matthijs Hans C P 
Published: July 2007

Abstract
The photosynthetic pigments of phototrophic microorganisms cover different regions of the solar light spectrum. Utilization of the light spectrum can be interpreted in terms of classical niche theory, as the light spectrum offers opportunities for niche differentiation and allows coexistence of species absorbing different colors of light. However, which spectral niches are available for phototrophic microorganisms? Here, we show that the answer is hidden in the vibrations of the water molecule. Water molecules absorb light at specific wavebands that match the energy required for their stretching and bending vibrations. Although light absorption at these specific wavelengths appears only as subtle shoulders in the absorption spectrum of pure water, these subtle shoulders create large gaps in the underwater light spectrum due to the exponential nature of light attenuation. Model calculations show that the wavebands between these gaps define a series of distinct niches in the underwater light spectrum. Strikingly, these distinct spectral niches match the light absorption spectra of the major photosynthetic pigments on our planet. This suggests that vibrations of the water molecule have played a major role in the ecology and evolution of phototrophic microorganisms.