The Transition to Post-industrial BMI Values Among US Children

In our opinion, the trend in the BMI values of US children has not been estimated accurately. We use five models to estimate the BMI trends of non-Hispanic US-born black and white children and adolescents ages 2-19 born 1941-2006 on the basis of all NHES and NHANES data sets. We also use some historical BMI values for comparison. The increase in BMIZ values during the period considered was on average 1.3σ (95% CI: 1.16σ; 1.44σ) among black girls, 0.8σ for black boys, 0.7σ for white boys, and 0.6σ for white girls. This translates into an increase in BMI values of some 5.6, 3.3, 2.4, and 1.5 units respectively. While the increase in BMI values started among the birth cohorts of the 1940s among black females, the rate of increase tended to accelerate among all four groups born in the mid-1950s to early-1960s with the contemporaneous spread of TV viewing. The rate of increase levelled off somewhat thereafter. There is some indication that among black boys and white girls born after c. 1990 adiposity has remained unchanged or perhaps even declined. The affects of the IT revolution of the last two decades of the century is less evident. Some regional evidence leads to the speculation that the spread of automobiles and radios affected the BMI values of boys already in the interwar period. We infer that the incremental weight increases are associated with the labor-saving technological developments of the 20th century which brought about many faceted cultural and nutritional revolutions.

The transition to Post-industrial BMI values among US children

Background: The trend in the BMI values of US children has not been estimated very convincingly because of the absence of longitudinal data. Our object is to estimate time series of BMI values by birth cohorts instead of measurement years. Methods: We use five regression models to estimate the BMI trends of non-Hispanic US-born black and white children and adolescents ages 2-19 between 1941 and 2004. Results: The increase in BMIZ values during the period considered was 1.3σ (95% CI: 1.16σ; 1.44σ) among black girls, 0.8σ for black boys, 0.7σ for white boys, and 0.6σ for white girls. This translates into an increase in BMI values of some 5.6, 3.3, 2.4, and 1.5 units respectively. While the increase in BMI values started among the birth cohorts of the 1940s among black girls, the rate of increase tended to accelerate among all four ethnic/gender groups born in the mid-1950s – early-1960s. Conclusion: Some regional evidence leads to the conjecture that the spread of automobiles and radios affected the BMI values of boys already in the interwar period. We suppose that the changes in lifestyle associated with the labor saving technological developments of the 20th century are associated with the weight gains observed. The increased popularity of television viewing was most prominently associated with the contemporaneous acceleration in BMI gain.BMI; BMIZ; US; children; youth; adolescents; NHANES; obesity epidemic; overweight

Binary Cepheids from optical interferometry

Classical Cepheid stars have been considered since more than a century as reliable tools to estimate distances in the universe thanks to their Period-Luminosity (P-L) relationship. Moreover, they are also powerful astrophysical laboratories, providing fundamental clues for studying the pulsation and evolution of intermediate-mass stars. When in binary systems, we can investigate the age and evolution of the Cepheid, estimate the mass and distance, and constrain theoretical models. However, most of the companions are located too close to the Cepheid (1-40 mas) to be spatially resolved with a 10-meter class telescope. The only way to spatially resolve such systems is to use long-baseline interferometry. Recently, we have started a unique and long-term interferometric program that aims at detecting and characterizing physical parameters of the Cepheid companions, with as main objectives the determination of accurate masses and geometric distances.Comment: 8 pages, Proceeding of the conference "Setting a new standard in the analysis of binary stars", September 2013, Leuven, Belgiu

RB1-Promotormethylierung bei Glioblastomen

Glioblastome sind astrozytäre Tumore, gehören zu den aggressivsten Tumorerkrankungen des Menschen und sind mit einer infausten Prognose vergesellschaftet. Auf der Suche nach Faktoren, welche Einfluss auf die Entstehung oder Progression von Glioblastomen haben, geriet zunehmend die epigenetische Forschung in den Fokus. Das RB1-Gen ist ein Tumorsuppressorgen, welches bei der Entstehung verschiedener Tumorerkrankungen eine entscheidende Rolle einnimmt. Es kann durch verschiedene Mechanismen ausgeschaltet werden, unter anderem durch die DNA-Methylierung seiner Promotorregion, wodurch die Expression des RB1-Gens unterdrückt wird. Die vorliegende Studie analysierte den Methylierungsstatus des RB1-Promotors bei 85 primären Glioblastomen. Methodisch kam dabei eine methylierungsspezifische PCR mit anschließender Auswertung der PCR-Produkte mithilfe einer Gelelektrophorese unter Verwendung von Ethidiumbromid zur Visualisierung der Banden im Gel zum Einsatz. Zielsetzung war, die Rolle der RB1-Promotormethylierung beim Glioblastom zu evaluieren. Eine Methylierung des RB1-Promotors konnte bei einer von 85 untersuchten Tumorproben nachgewiesen werden (1,2%). Eine Korrelation des RB1-Methylierungsstatus mit anderen erhobenen Parametern war entsprechend statistisch nicht sinnvoll. Das mittlere Gesamtüberleben der Patientenpopulation lag bei 15,7 Monaten, das mittlere progressionsfreie Überleben bei 9,0 Monaten. Bei 6,1% der Patienten konnte eine IDH1- Mutation nachgewiesen werden, wobei dies mit jüngerem Patientenalter bei Erstdiagnose vergesellschaftet war. Zudem war bei 48,2% der Patienten eine Methylierung des MGMT Promotors vorhanden. Bei mittlerem Alter der Patientenpopulation von 60,67 Jahren zeigte sich eine signifikante Verkürzung von Gesamtüberleben und progressionsfreiem Überleben mit zunehmendem Alter bei Erstdiagnose. Ebenso stellten wir fest, dass Patienten mit hohem Karnofsky-Score bei Erstdiagnose ein signifikant längeres Gesamtüberleben sowie progressionsfreies Überleben vorwiesen. Insgesamt zeigte nur bei einem von 85 Patienten die Tumorprobe eine Methylierung des RB1- Promotors – dies ist umso überraschender, da sich in der Literatur diesbezüglich teils widersprüchliche Ergebnisse finden. Im Vergleich zu den vorliegenden, häufig kleineren Studien zu dieser Fragestellung konnten wir in dieser Studie mit der höchsten Fallzahl sowie als erste Studie unter Verwendung der aktuellen WHO-Klassifikation eine klare Aussage zu diesem Thema treffen. Unsere Studienergebnisse zeigen, dass die RB1-Promotormethylierung kein relevantes Ereignis in der Entstehung und Progression des Glioblastoms darstellt.Glioblastomas are astrocytic tumors, are among the most aggressive tumor diseases of man, and are associated with an unfavorable prognosis. In search of factors that have an influence on the development or progression of glioblastomas, the epigenetic research came into focus. The RB1 gene is a tumor suppressor gene which plays a key role in the development of various tumor diseases. It can be turned off by various mechanisms, among other things by DNA methylation of its promotor region. This study analyzed the methylation status of the RB1 promotor of 85 primary glioblastomas. Methodically, a methylation-specific PCR with subsequent evaluation of results of the PCR products via gel electrophoresis using ethidium bromide to visualize the bands in the gel was used. The objective was to evaluate the role of the RB1 promotor methylation in glioblastomas. Methylation of the RB1 promotor could be found in one of the 85 analyzed tumor samples (1,2%). According to that, a correlation of the RB1 methylation status with other analyzed items didn’t make sense statistically. The average overall survival of the patient population was 15,7 months, the average progression free survival was 9 months. In 6,1% of the patients, an IDH1 mutation could be detected, this was associated with a younger age of the patients at initial diagnosis. Additionally, in 48,2% of the patients, a methylation of the MGMT-promotor was present. With an average age of the patients' population of 60,67 years, there was a significant shortening of overall survival and progression free survival with increasing age at initial diagnosis. Likewise, we found out that patients with a high Karnofsky-Score at initial diagnosis had a significantly longer overall survival and progression free survival. Overall, in only one of the 85 Patients, the tumor sample showed a methylation of the RB1- promotor – this is even more surprising as in the literature, there are partly contradictory results found concerning this matter. In comparison to the available, often smaller studies regarding this issue, we could in this study, with the highest case number as well as as the first study using the recent WHO-classification, make a clear statement on this subject. Our study results indicate that the RB1 promotor methylation is not a relevant event in the development and progression of glioblastoma

Extended envelopes around Galactic Cepheids IV. T Monocerotis and X Sagittarii from mid-infrared interferometry with VLTI/MIDI

Aims. We study the close environment of nearby Cepheids using high spatial resolution observations in the mid-infrared with the VLTI/MIDI instrument, a two-beam interferometric recombiner. Methods. We obtained spectra and visibilities for the classical Cepheids X Sgr and T Mon. We fitted the MIDI measurements, supplemented by B, V, J, H, K literature photometry, with the numerical transfer code DUSTY to determine the dust shell parameters. We used a typical dust composition for circumstellar environments. Results. We detect an extended dusty environment in the spectra and visibilities for both stars, although T Mon might suffer from thermal background contamination. We attribute this to the presence of a circumstellar envelope (CSE) surrounding the Cepheids. This is optically thin for X Sgr (tau(0.55microns) = 0.008), while it appears to be thicker for T Mon (tau(0.55micron) = 0.15). They are located at about 15-20 stellar radii. Following our previous work, we derived a likely period-excess relation in the VISIR PAH1 filter, f(8.6micron)[%]= 0.81(+/-0.04)P[day]. We argue that the impact of CSEs on the mid-IR period-luminosity (P-L) relation cannot be negligible because they can bias the Cepheid brightness by up to about 30 %. For the K-band P-L relation, the CSE contribution seems to be lower (< 5 %), but the sample needs to be enlarged to firmly conclude that the impact of the CSEs is negligible in this band.Comment: Accepted for publication in Astronomy and Astrophysic

Observational calibration of the projection factor of Cepheids I. The Type II Cepheid kappa Pavonis

The distances of pulsating stars, in particular Cepheids, are commonly measured using the parallax of pulsation technique. The different versions of this technique combine measurements of the linear diameter variation (from spectroscopy) and the angular diameter variation (from photometry or interferometry) amplitudes, to retrieve the distance in a quasi-geometrical way. However, the linear diameter amplitude is directly proportional to the projection factor (hereafter p-factor), which is used to convert spectroscopic radial velocities (i.e., disk integrated) into pulsating (i.e., photospheric) velocities. The value of the p-factor and its possible dependence on the pulsation period are still widely debated. Our goal is to measure an observational value of the p-factor of the type-II Cepheid kappa Pavonis, whose parallax was measured with an accuracy of 5% using HST/FGS. We used this parallax as a starting point to derive the p-factor of kappa Pav, using the SPIPS technique, which is a robust version of the parallax-of-pulsation method that employs radial velocity, interferometric and photometric data. We applied this technique to a combination of new VLTI/PIONIER optical interferometric angular diameters, new CORALIE and HARPS radial velocities, as well as multi-colour photometry and radial velocities from the literature. We obtain a value of p = 1.26 +/- 0.07 for the p-factor of kappa Pav. This result agrees with several of the recently derived Period-p-factor relationships from the literature, as well as previous observational determinations for Cepheids. Individual estimates of the p-factor are fundamental to calibrating the parallax of pulsation distances of Cepheids. Together with previous observational estimates, the projection factor we obtain points to a weak dependence of the p-factor on period.Comment: 8 pages, 6 figures, accepted in A&

Les Céphéides et l'échelle des distances galactiques: apport de l'interférométrie à longue base

Cepheids have been used since more than a century as standard candles to estimate distances in the Universe, owing to the relation between their pulsation period and absolute magnitude. The calibration of this relation (also called "Leavitt law", in homage to its discoverer) is based on independent distance estimates, that are generally derived from the parallax-of-pulsation method. This rather simple technique makes a comparison of the angular diameter variation (measured for example through surface brightness relationships) and the linear diameter variation (obtained through an integration of the radial velocity curve). During my PhD I used a very innovative implementation of this method : the SPIPS code developed by Antoine Mérand. This technique allows a simultaneous adjustement of all the available observables (multi-filter and multi-band photometry, radial velocities, interferometric diameters and effective temperatures), which results in a much better statistical precision. The code also incorporates atmospheric models allowing to take into account the Cepheids physics, and to ensure a better control of the systematics (for instance, circumstellar envelops make the stars appear brighter in the infrared bands). Although the method is quite precise and elegant, it only allows to mesure the distance to the projection factor p, a parameter used to convert radial velocities (deduced from the spectroscopy) into velocities of pulsation (actual displacement of the atmosphere). The value of p and its possible dependence on the pulsation period are still widely debated. For the rare Cepheids whose distances are already known precisely enough (for example through a parallax measurement), it is possible to make an invert use of the SPIPS method and track down the value of p, which is what I did during my PhD. Thanks to this method, I could first calculate the p-factor of the type II Cepheid κ Pavonis. This study led to p = 1.26 ± 0.07. I then extended this work to a larger sample of Cepheids whose parallaxes have been measured with the HST, and to the famous long-period Cepheid RS Pup, whose distance has been measured thanks to the light echoes phenomenon. Contrary to the predictions of some authors, the global study points at a rather weak dependence of p on the pulsation period. For the moment we propose to use the constant value of p = 1.326 ± 0.021. In the current state of the art, the precision is not limited anymore by the method itself, but by the distance measurements. The Gaia parallaxes at 1% will help to progress in that whole problematic. This preliminary work already proved the feasibility of the method and led us to very promising results.Les Céphéides sont utilisées depuis plus d’un siècle comme chandelles cosmiques pour estimer des distances dans l’univers, grâce à la relation qui unie leur période de pulsation et leur luminosité absolue. La calibration de cette relation (dite "Loi de Leavitt", en hommage à sa découvreuse) repose sur des estimations indépendantes de distances, qui sont généralement réalisées grâce à la méthode de la parallaxe de pulsation. Cette technique assez simple repose sur la comparaison de la variation de diamètre angulaire (mesurée par exemple via des relations de brillance de surface) et de la variation de diamètre linéaire (obtenue après une simple intégration de la courbe de vitesse radiale). Durant ma thèse j’ai fait usage d’une implémentation novatrice de cette méthode : le code SPIPS développé par Antoine Mérand. Celui-ci permet un ajustement simultané de toutes les observables disponibles (photométrie multi-filtre et multi-bande, vitesses radiales, diamètres interférométriques et températures effectives), se traduisant par une meilleur précision statistique. Le code intègre également des modèles d’atmosphère permettant de prendre en compte la physique des Céphéides, et d’assurer un meilleur contrôle des systématiques (par exemple, la présence d’une enveloppe circumstellaire se traduit par un excès apparent de la magnitude infrarouge). Bien que précise et élégante, cette méthode ne permet de mesurer des distances qu’à un paramètre près, le facteur de projection p utilisé pour convertir la vitesse radiale (déduite de la spectroscopie) en vitesse de pulsation. La valeur de p et sa dépendance avec la période de pulsation sont encore largement débattues. Pour les rares Céphéides dont la distance est connue avec une précision suffisante (par exemple grâce à une mesure de parallaxe), il est possible de faire un usage inverse de la méthode SPIPS et de remonter à la valeur de p, et c’est ce que j’ai fait durant ma thèse. Grâce à cette méthode, j’ai tout d’abord calculé le p-facteur de la Céphéide de type II κ Pavonis, pour laquelle nous aboutissons à p = 1.26 ± 0.07. J’ai ensuite étendu mon étude à un plus grand échantillon de Céphéides galactiques de parallaxe connue, auxquelles j’ai ajouté RS Pup, célèbre pour ses échos de lumière. Contrairement aux prédictions de certains auteurs, l’étude globale de ces étoiles a permis de conclure à une dépendance plutôt faible de p en fonction de la période. De fait, nous proposons pour le moment d’utiliser une valeur constante moyenne de p = 1.326 ± 0.021. Dans l’état de l’art actuel, la précision n’est pas limitée par la méthode, mais par les mesures de distance elles-mêmes. L’arrivée des parallaxes à moins de 1% du satellite Gaia permettra sans doute une avancée rapide dans cette problématique, ce travail préliminaire ayant dores et déjà permis de démontrer la faisabilité de la méthode et d’aboutir à des résultats prometteurs

Observational calibration of the projection factor of Cepheids. II. Application to nine Cepheids with HST/FGS parallax measurements

The distance to pulsating stars is classically estimated using the parallax-of-pulsation (PoP) method, which combines spectroscopic radial velocity measurements and angular diameter estimates to derive the distance of the star. An important application of this method is the determination of Cepheid distances, in view of the calibration of their distance scale. However, the conversion of radial to pulsational velocities in the PoP method relies on a poorly calibrated parameter, the projection factor (p-factor). We aim to measure empirically the value of the p-factors of a homogeneous sample of nine Galactic Cepheids for which trigonometric parallaxes were measured with the Hubble Space Telescope Fine Guidance Sensor. We use the SPIPS algorithm, a robust implementation of the PoP method that combines photometry, interferometry, and radial velocity measurements in a global modeling of the pulsation. We obtained new interferometric angular diameters using the PIONIER instrument at the Very Large Telescope Interferometer, completed by data from the literature. Using the known distance as an input, we derive the value of the p-factor and study its dependence with the pulsation period. We find the following p-factors: 1.20 $\pm$ 0.12 for RT Aur, 1.48 $\pm$ 0.18 for T Vul, 1.14 $\pm$ 0.10 for FF Aql, 1.31 $\pm$ 0.19 for Y Sgr, 1.39 $\pm$ 0.09 for X Sgr, 1.35 $\pm$ 0.13 for W Sgr, 1.36 $\pm$ 0.08 for $\beta$ Dor, 1.41 $\pm$ 0.10 for $\zeta$ Gem, and 1.23 $\pm$ 0.12 for $\ell$ Car. These values are consistently close to p = 1.324 $\pm$ 0.024. We observe some dispersion around this average value, but the observed distribution is statistically consistent with a constant value of the p-factor as a function of the pulsation period. The error budget of our determination of the p-factor values is presently dominated by the uncertainty on the parallax, a limitation that will soon be waived by Gaia.Comment: 18 pages, 13 figure

Kindheitsbelastungsfaktoren und übersteigerte Würgereaktionen

Beim übersteigerten Würgereiz handelt es sich im in der Regel um ein lebenslanges Problem, es ist zu vermuten, dass auslösende Faktoren während der Kindheit zu finden sind. Die Auswertung von 167 Patientendaten zeigte, dass mehr Frauen als Männer von dem Problem betroffen sind. Männer geben öfter einen Beginn der Problematik in der Kindheit an, Frauen sehen den Beginn der Problematik im Zusammenhang mit der Anfertigung von Zahnersatz oder bestimmten Ereignissen. Die Auswertung des Fragebogens zur Ermittlung von Kindheitsbelastungsfaktoren ergab, dass das Auftreten des Würgereizes weder vom Alter, Geschlecht oder bestimmten allgemeinen oder psychischen Erkrankungen abhängt. Die Angst vor der zahnärztlichen Behandlungssituation, die bei allen Befragten seit Kindheit besteht, ist ein wesentlicher Faktor. Der Würgereiz kann, wie die Angst, durch vertikale und horizontale Übertragung weitergegeben werden, wobei eine gestörte Familienatmosphäre signifikant häufig festzustellen ist

Spectro-Photo-Interferometry of Stellar Pulsation (SPIPS)

We present our implementation of the parallax of pulsation method which integrates all observables and physical modelling of the photosphere to get the best statistical precision and controlled biases. This method has been validated on well known stars and used to estimate observationally the projection factor of the HST-FGS sample. Our future developments include application to the Gaia Cepheids and modelling of the spectrum