Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- II: First Results on NGC 4631

We present the first results from the CHANG-ES survey, a new survey of 35 edge-on galaxies to search for both in-disk as well as extra-planar radio continuum emission. The motivation and science case for the survey are presented in a companion paper (Paper I). In this paper (Paper II), we outline the observations and data reduction steps required for wide-band calibration and mapping of EVLA data, including polarization, based on C-array test observations of NGC 4631. With modest on-source observing times (30 minutes at 1.5 GHz and 75 minutes at 6 GHz for the test data) we have achieved best rms noise levels of 22 and 3.5 $\mu$Jy beam$^{-1}$ at 1.5 GHz and 6 GHz, respectively. New disk-halo features have been detected, among them two at 1.5 GHz that appear as loops in projection. We present the first 1.5 GHz spectral index map of NGC 4631 to be formed from a single wide-band observation in a single array configuration. This map represents tangent slopes to the intensities within the band centered at 1.5 GHz, rather than fits across widely separated frequencies as has been done in the past and is also the highest spatial resolution spectral index map yet presented for this galaxy. The average spectral index in the disk is $\bar\alpha_{1.5 GHz}\,=\,-0.84\,\pm\,0.05$ indicating that the emission is largely non-thermal, but a small global thermal contribution is sufficient to explain a positive curvature term in the spectral index over the band. Two specific star forming regions have spectral indices that are consistent with thermal emission. Polarization results (uncorrected for internal Faraday rotation) are consistent with previous observations and also reveal some new features. On broad scales, we find strong support for the notion that magnetic fields constrain the X-ray emitting hot gas.Comment: Accepted to the Astronomical Journal, Version 2 changes: Added acknowledgement to NRA

Epithelial and dendritic cells in the thymic medulla promote CD4(+)Foxp3(+) regulatory T cell development via the CD27-CD70 pathway

This work was supported by grants NKI 2004-3087 and NKI 2008-2023 from the Dutch Cancer Society to J. Borst, European Molecular Biology Organization long-term fellowships to J.M. Coquet and J.C. Ribot, a Rubicon (The Netherlands Organisation for Scientific Research [NWO]) fellowship to J.M. Coquet, and a Fundação para a Ciência e Tecnologia project grant (PTDC/SAU-MII/104158/2008) and a European Research Council starting grant (StG260352) to B. Silva-Santos. J.F. Neves is funded by the Fundação para a Ciência e Technologia of Portugal; D.J. Pennington is funded by the Wellcome Trust

Une approche logico-symbolique des connaissances nuancées via des modificateurs linguistiques

Le traitement de la connaissance imprécise occupe une place centrale dans les recherches en Intelligence Artificielle. Parmi les approches proposées, on peut faire ressortir deux grandes catégories principales : 1. celles numériques se basant sur la théorie des ensembles flous et la logique floue, 2. celles symboliques dédiées au traitement de l'imprécision de nature qualitative. Ces approches se basent sur la théorie des multi-ensembles et des logiques symboliques multivalentes. Dans cette thèse, nous présentons une approche qualitative purement symbolique de représentation et d'exploitation des connaissances imprécises du langage naturel. Cette approche est construite sur le substrat d'une logique symbolique multivalente proposée par Pacholczyk. Dans un premier temps, nous proposons une modélisation multi-ensembliste pour les termes imprécis du langage. Dans cette modélisation, nous associons à chaque terme imprécis une " réglette " dont la géométrie représente le caractère imprécis et graduel de ce terme. La description de cette " réglette " est fournie par un expert dans un langage déclaratif et purement symbolique. En nous basant sur la nouvelle modélisation, nous définissons des modificateurs linguistiques (notamment les modificateurs de précision et ceux de translation) dans un contexte multi-ensembliste. Ensuite, nous proposons de nouvelles règles de Modus Ponens généralisé enrichissant ainsi le système d'exploitation symbolique de connaissances imprécises proposé par Pacholczyk. Dans ces généralisations, nous utilisons une relation de similarité multi-ensembliste et une relation de proximité. La première est une relation réflexive, symétrique et " faiblement transitive ". La deuxième est une relation réflexive et " faiblement transitive ".ANGERS-BU Lettres et Sciences (490072106) / SudocSudocFranceF

A Statistical Probability Theory for a Symbolic Management of Quantified Assertions

In this paper we present a new approach to a symbolic treatment of quantified statements having the following form "Q A's are B's", knowing that A and B are labels denoting sets, and Q is a linguistic quantifier interpreted as a proportion evaluated in a qualitative way. Our model can be viewed as a symbolic generalization of statistical conditional probability notions as well as a symbolic generalization of the classical probabilistic operators. Our approach is founded on a symbolic finite M-valued logic in which the graduation scale of M symbolic quantifiers is translated in terms of truth degrees. Moreover, we propose symbolic inference rules allowing us to manage quantified statements

Setting the threshold for extra-thymic differentiation of Foxp3+ Tregs: TGF-β-dependent and T-cell autonomous

There is a lack of clarity regarding the conditions supporting de novo induction of Tregs. While there is widespread agreement in the literature over the need for optimal stimulation conditions and exogenous TGF-β in vitro, a number of studies indicate that sub-immunogenic conditions induce Tregs in vivo. These seemingly disparate findings have hindered the ability to pin down the conditions promoting Treg induction, including the role of co-stimulation and even the necessity for TGF-β. Two studies in this issue of the European Journal of Immunology re-examine these previous findings in detail and shed some light on the controversy. These studies demonstrate that Treg induction depends on reaching a certain threshold of signal strength: the requirement for co-stimulation is therefore not absolute but dictated by the strength of other signals received by the T cell. Furthermore, these studies demonstrate that the only source of TGF-β required for the induction of Tregs under sub-optimal condition is the T cells themselves. Overall, the picture that emerges is one where sub-immunogenicity, rather than a requirement for exogenous TGF-β, defines the conditions that support TGF-β-dependent Foxp3 induction in a T-cell autonomous fashion. The next challenge lies in utilizing this knowledge for the purpose of inducing Tregs for therapeutic gain

تعامل نوعى مع التأكيدات القياسية

In this paper we present a newapproach to a symbolic treatment ofquan-tified statements having the following form "Q A's are 5's", knowing that A and B are labels denoting sets,and Q is a linguistic quantifier interpreted as a proportion evaluated in a qualitative way. Our model can be viewed as a symbolic generalization of statistical conditional probability notions as well as a symbolic generalization of the classical probabilistic operators.Our approach is founded on a symbolic finite M-valued logic in which the graduation scale ofM symbolic quantifiers is translated in terms of truth degrees. Moreover,we propose symbolic inference rules allowing us to manage quantified statements. Finally, we present a symbolic formal-isation of direct inference principle allowing us to reason with particular individuals.في هذا البحث ، نقدم طريقة جديدة للمعالجة الرمزية للجمل القياسية المحدودة ذات الشكل التالي : "ك أ ← ب" علما بأن أ وب هن مسميات تمثل مجموعات بينما ك هو قياس لغوي يمثل نسبة مقيمة بطريقة نوعية، نموذجنا هذا، يمكن اعتباره تعميم رمزي من التصورات الاحتمالية الشرطية الإحصائية، وأيضا تعميم رمزي كلاسيكي للمعامل الاحتمالية، طريقتنا معتمدة بشكل رئيسي على المنطق الرمزي المحدود حيث أن مقياس التدرج في هذا المنطق ممثل بدرجات حقائق منطقية مختلفة، علاوة على ذلك ، فإننا نقترع قواعد استدلال رمزية تسمح لنا بالتعامل مع الجمل القياسية المحدودة وأخير نقدم تشكل رمزي من مبدأ الاستدلال المباشر يسمح لنا بالتعامل المنطقي الخصوصي