bluuebunny/crossref_metadata_2025 huggingface dataset:
Hume's Defence of Science
Authors: Wilson Fred
Published: April 2010

It is incorrect to construe Hume as a Pyrrhonian sceptic. Or so I have argued elsewhere. To the contrary, Hume in fact offers a detailed defence of the thesis that the norms of scientific inference, that is, the “rules by which to judge of causes and effects”, arereasonablerules to follow in forming our beliefs. Conforming to these rules in its formation of causal beliefs is astrategythe understanding employs in order to satisfy the end of curiosity (T271). Science is reasonable because, so far as we can, within our fallible limits, discover, it is the strategy of belief formation that is the best means of achieving our end of truth, insofar as the latter is, within our fallible limits, attainable.
Otto Neurath et la critique du pseudo-rationalisme (leçons épistémologiques des sciences sociales)
Authors: Rosier Michel
Published: April 2010

Otto Neurath est intéressant à plus d'un titre. En premier lieu, il a joué un rôle central dans le développement institutionnel du mouvement dénommé « empirisme logique » dont certains interprètes ont considerablement réduit l'étendue et tronqué les thèses. En second lieu, intellectuellement, il occupe une place importante dans les réflexions épistémologiques et politiques d'avant la seconde guerre mondiale, comme en temoigne le fait que Karl Popper le prenne pour cible dans La logique de la découverte scientifique ou Friedrich Hayek dans La route de la servitude. En troisième lieu, il est, comme le note Popper, l'incarnation d'une approche épistémologique originale (Popper, 1944–45, 165–166).
Le sens du titre Etre et temps
Authors: Grondin Jean
Published: April 2010

Dans des notes de 1941, publiées en annexe à son cours sur Schelling, Heidegger met en relief trois significations bien distinctes du titre Sein und Zeit. Ce titre serait, en premier lieu, le nom d'un événement dans l'être lui-même; ensuite, le mot d'ordre d'une méditation au sein de l'histoire de la pensée; enfin, le titre d'un traité qui tente un parcours de cette pensée. L'ouvrage intitulé Etre et temps doit done être distingué de la « nécessité » qu'indiquent l'événement et la méditation historiale Sein und Zeit. Quatorze ans après sa publication, Sein und Zeit est devenu un événement de l'être lui-meme ainsi qu'une balise de l'histoire de la pensée occidentale. La projection, apparemment présomptueuse, de Etre et temps dans l'histoire de l'ětre reléve-t-elle de l'auto-interprétation tardive du second Heidegger ou etait-elle déjá à la racine de l'oeuvre de 1927, le chef-d'oeuvre philosophique du vingtième siècle? Dequel droit, plus généralement, le titre d'un livre peut-il se déclarer événement de l'être? Afin de répondre à de telles questions, il faut, bien sûr, avoir compris, ou entrevu, ce que signifie la formule Sein und Zeit. Titre assurément énigmatique, même s'il ne se constitue que de vocables très familiers. « Etre », « temps », « et »: autant de mots que nous employons tous les jours, sinon dans toutes les phrases. Mais « être et temps »? Quel est le sens d'un titre pareil? Cette étude se propose d'esquisser une réponse à cette question en cernant l'horizon des questions délimité par ce titre en 1927 en vue de saisir pourquoi, depuis les bases posées dans Sein und Zeit, ce titre en est venu à circonscrire un événement de l'être et un tournant de la philosophie.
Wright's Enquiry Concerning Humean Understanding
Authors: Wilson Fred
Published: April 2010

From the time of Reid through Coleridge to T. H. Green, Hume was interpreted as a sceptic and as a wholly negative philosopher. And from their perspective such an interpretation no doubt makes some sense, given the vested interest in religion and the absolute of the idealists: from that perspective it is an essential part of a positive position that it take one beyond the realm of ordinary objects known by sense experience to a realm of entities that transcend that world of everyday life. That interpretation lingers on, like bad jokes, to retail in Philosophy 100 classes. On the other hand, in an age where the demand that one have access to a transcendent entity is less insistent, it has become possible to challenge the orthodox reading of Hume. The first to do this was Norman Kemp Smith, who argued that, while Hume was a sceptic, he in fact also had a positive view, not to be sure that of Reid & Co., but that of anaturalist, that is, one who holds that our beliefs, and our moral commitments, are none of them rational, none of them products of reason, but rather are products of our instinctive and passionate natures. This interpretation continues to have important defenders such as Popkin and Stroud. More recently, however, some scholars have gone further and argued that there are good senses in which Hume is not a sceptic, and that he constructs a case that our instinctual beliefs are not only natural but also rational. Major works defending this reading of Hume as a naturalized epistemologist are those of Livingston and Jones. The Kemp Smith interpretation has, however, found a major new defender in John Wright'sThe Sceptical Realism of David Hume.
Reply to “Forrester's Paradox”
Authors: Robinson Richard E.
Published: April 2010

Forrester claims to have shown that a contradiction can be derived from a set of two apparently innocuous moral (or legal) rules together with standard deontic logic (SDL), a principle for adverbial detachment, and a statement of fact. Let l be a system of laws that has the following as immediate consequences:

(1) It is obligatory* that Smith not murder Jones.

(2) It is obligatory; that, if Smith murders Jones, then Smith murders Jones gently.
NECESSARY NUDES:ḤADĀTHAANDMUʿĀṢIRAIN THE LIVES OF MODERN LEBANESE
Authors: Scheid Kirsten
Published: April 2010

In his studio in Beirut in 1929, the young artist Moustapha Farroukh (1901–57) envisioned a composition to change his society. He hoped his oil painting would incite broad support among his fellow Lebanese for a revolution in conventional gender relations and women's participation in the urban social order. He titled the pictureThe Two Prisonersand based it on a European convention for representing the East: the Nude odalisque (Figure 1). The resulting painting exemplifies the complex role Arab intellectuals of the early 20th century played in the formation of modern art and universal modernity. Leading artists in Mandate-era Beirut felt compelled to paint Nudes and display them as part of a culturing process they calledtathqīf(disciplining or enculturing). To a large extent,tathqīfconsisted of recategorizing norms for interaction and self-scrutiny. Joseph Massad has revealed that one crucial component oftathqīfwas the repudiation of behaviors and desires associated with the Arab Past, such as male homosexuality. An equally important component was the cultivation of “modern,” “masculine” heterosexual eroticism and a dutiful feminine compliance associated withḥadātha(novelty) andmuʿāṣira(contemporaneity). This was accomplished through the use of a genre that was deliberately new and alien in both its material media and its impact on makers and viewers.
SEXOLOGY IN THE YISHUV: THE RISE AND DECLINE OF SEXUAL CONSULTATION IN TEL AVIV, 1930–39
Authors: Kozma Liat
Published: April 2010

This article examines the assimilation of sexology and sexual reform in the Yishuv of the 1930s. Prominent German sexologists visited Palestine, texts they authored were translated to Hebrew and Yiddish, and members of the Yishuv community traveled to central Europe to learn sexual-reform ideas. In 1931 and 1932, three consultation centers were opened in Tel Aviv, accompanied by Q&A columns in the general and medical press. In these centers and columns, men and women consulted medical doctors on contraception, impotence, abortions, and the everyday of heterosexual life. This short-lived experience was inspired by similar European experiences, especially in Weimar Germany and Bolshevik Russia. The 1930s discourse on sexuality was sometimes compatible with mainstream Zionist ideology and sometimes at odds with it. It came to an end during the last years of the decade, following the Arab Revolt, the Holocaust, and the demographic struggle over Palestine.
HIGH VISIBILITY, LOW PROFILE: THE SHIʿA IN OMAN UNDER SULTAN QABOOS
Authors: Valeri Marc
Published: April 2010

Since the U.S. invasion of Iraq in 2003, one of the most popular reading grids of Middle East politics has been the increased impact of the Shiʿi issue on the national political agendas of Arab states. This article focuses on the place of one of the less studied Shiʿi groups, the Shiʿa of Oman, who represent around three percent of the national population, in the nation-building project initiated by Sultan Qaboos since 1970 to maintain political stability and legitimize his power. I argue that the special relationship the Shiʿa have maintained with the ruling elite in Oman and the prominent role some of them are enjoying in the Omani economy help explain their weak insertion into transnational Shiʿi networks in the Gulf and the fact that they have never questioned the validity of the Omani nation under Qaboos as a political framework. But the socioeconomic changes caused by the end of the rent-based welfare-state model has led recently to an increase in mutual prejudices and social grievances. The Shiʿa, because of their high socioeconomic visibility, are likely to find themselves at the center of other groups’ complaints.
MIGRATION, WAR, AND THE MAKING OF A TRANSNATIONAL LEBANESE SHIʿI COMMUNITY IN SENEGAL
Authors: Leichtman Mara A.
Published: April 2010

This article investigates links between religious and political transnationalisms through analyzing responses to the 2006 Lebanon war from the diaspora. I examine the role of a shaykh in bringing Lebanese Shiʿa in Senegal “back to Islam” as well as (spiritually if not physically) back to Lebanon. I explore his efforts to institute formal religious education through a Friday sermon, encourage public expressions of piety, and introduce new religious rituals in commemorations of ʿAshuraʾ and Ramadan. This ethnographic study adds a diaspora component to debates about Lebanese nationalism and suggests that the ideology of the umma does not hold for a marginalized Muslim minority community in a Muslim majority country, which instead defines itself along reformulated ethnic, religious, and national boundaries. The paper contributes to newly emerging scholarship on transnational Shiʿi linkages by demonstrating how the African example adds another dimension to our understanding of the relationship between religion and nationalism in the Middle East.
Water bells formed on the underside of a horizontal plate. Part 1. Experimental investigation
Authors: JAMESON GRAEME J. , JENKINS CLAIRE E. , BUTTON ELEANOR C. , SADER JOHN E.
Published: April 2010

In this study we report discovery of a new type of water bell. This is formed by impinging a vertical liquid jet on to the underside of a large horizontal flat plate. After impact, the liquid spreads radially along the plate before falling at an abrupt unspecified radius. This falling liquid may then coalesce to form a curtain which encloses a volume of air. When the flow rate of the impinging jet is altered from the value at initial formation, a pronounced hysteretic effect in the water bell shape can be observed. We present detailed observations of these new phenomena, including the size and nature of the flow underneath the plate and the shape of the liquid curtain. These observations are interpreted theoretically in a companion paper (Part 2, Button et al. vol. 649, 2010, pp. 45–68).
Water bells formed on the underside of a horizontal plate. Part 2. Theory
Authors: BUTTON ELEANOR C. , DAVIDSON JOHN F. , JAMESON GRAEME J. , SADER JOHN E.
Published: April 2010

In a companion paper (Part 1, Jameson et al. J. Fluid Mech. vol. 649, 2010, 19–43), the discovery of a new type of water bell was reported. When a vertical liquid jet impacts on the underside of a large horizontal plate, the resulting thin film spreads radially along the plate to an unspecified abrupt departure point, from whence it falls away from the plate of its own accord. The departure radius of the fluid from the plate is seen to depend strongly on the volumetric flow rate. The falling liquid may then coalesce to form a water bell. Here we present a theoretical analysis and explanation of this phenomenon. A force balance determining the maximum radial extension of the thin film flow along the plate is considered as a mechanism for fluid departure from the plate, for which an analytical model is developed. This model gives good predictions of the measured radius of departure. When a water bell has been formed, and the flow rate is altered, many interesting shapes are produced that depend on the shapes at previous flow rates. We discuss the origin of this hysteresis, and also present a leading order theory for the bell shape under a regime of changing flow rate. The models are compared with experimental results spanning two orders of magnitude in viscosity.
Testing the limits of quasi-geostrophic theory: application to observed laboratory flows outside the quasi-geostrophic regime
Authors: WILLIAMS PAUL D. , READ PETER L. , HAINE THOMAS W. N.
Published: April 2010

We compare laboratory observations of equilibrated baroclinic waves in the rotating two-layer annulus, with numerical simulations from a quasi-geostrophic model. The laboratory experiments lie well outside the quasi-geostrophic regime: the Rossby number reaches unity; the depth-to-width aspect ratio is large; and the fluid contains ageostrophic inertia–gravity waves. Despite being formally inapplicable, the quasi-geostrophic model captures the laboratory flows reasonably well. The model displays several systematic biases, which are consequences of its treatment of boundary layers and neglect of interfacial surface tension and which may be explained without invoking the dynamical effects of the moderate Rossby number, large aspect ratio or inertia–gravity waves. We conclude that quasi-geostrophic theory appears to continue to apply well outside its formal bounds.
Moderately three-dimensional separated and reattaching turbulent flow
Authors: HARDMAN J. R. , HANCOCK P. E.
Published: April 2010

A fully three-dimensional turbulent separated flow was set up such that it had a systematic link to two-dimensional flow, as a way of investigating the more complicated nature of this flow type. The central region of the flow was fully three-dimensional, but was bounded on its sides by regions of ‘spanwise invariance’ in which the flow was invariant in the lateral direction, or very nearly so. A special case of spanwise invariance, which is statistically two-dimensional, is one in which the streamlines are also coplanar, or at least nominally so in numerous experimental studies. Another aspect of the present arrangement is that the side regions should ideally provide well-defined boundary conditions. The separation was formed downstream of a doubly swept normal flat plate, forming a ‘v’-shaped separation line, mounted on the front of a splitter plate, mounted in the centre of the wind tunnel working section. The predominantly inward flow to the central region implies a negative lateral strain rate (∂W/∂z), but all nine strain rates are non-zero. Measurements were made using pulsed-wire anemometry techniques for mean velocities, Reynolds stresses and wall shear stress. Even though the sweep angle is mild at ±10°, the effect is to increase the bubble height by over 50% in its centre to create a ‘bulge’, symmetrical about the centreline. The degree of three-dimensionality is described as moderate in that the peak inflow velocity from the side regions is less than 0.2 of the free-stream velocity, but comparable with the peak in the reverse-flow velocity. A larger sweep angle would give a larger inflow velocity. A separate study (Cao & Hancock, Eur. J. Mech. B/Fluids, vol. 23, 2004, p. 519) has shown that the bulge persists very far downstream, so that accurate physical modelling of the separated region is likely to be important in modelling the flow well downstream. An intermediate region exists between the invariant side region and the bulge, where all the stress levels are reduced, as would be expected from the effects of streamline convergence. Although overall there is a flow inward to the centre (streamline convergence), part of the overlying shear layer is subjected to diverging flow and an intensification of Reynolds stresses near the centre of the bulge.
Collapse of void arrays under stress wave loading
Authors: SWANTEK A. B. , AUSTIN J. M.
Published: April 2010

The interaction of an array of voids collapsing after passage of a stress wave is studied as a model problem relevant to porous materials, for example, to energy localization leading to hotspot formation in energetic materials. Dynamic experiments are designed to illuminate the hydrodynamic processes of collapsing void interactions for eventual input into device-scale initiation models. We examine a stress wave loading representative of accidental mechanical insult, for which the wave passage length scale is comparable with the void and inter-void length scales. A single void, two-void linear array, and a four-void staggered array are studied. Diagnostic techniques include high-speed imaging of cylindrical void collapse and the first particle image velocimetry measurements in the surrounding material. Voids exhibit an asymmetrical collapse process, with the formation of a high-speed internal jet. Volume and diameter versus time data for single void collapse under stress wave loading are compared with literature results for single voids under shock-wave loading. The internal volume history does not fall on a straight line and is in agreement with simulations, but in contrast to existing linear experimental data fits. The velocity field induced in the surrounding material is measured to quantify a region of influence at selected stages of single void collapse. In the case of multiple voids, the stress wave diffracts in response to the presence of the upstream void, affecting the loading condition on the downstream voids. Both collapse-inhibiting (shielding) and collapse-triggering effects are observed.
A bicharacteristic formulation of the ideal MHD equations
Authors: GUPTA HARI SHANKER , PRASAD PHOOLAN
Published: April 2010

On a characteristic surface Ω of a hyperbolic system of first-order equations in multi-dimensions (x, t), there exits a compatibility condition which is in the form of a transport equation along a bicharacteristic on Ω. This result can be interpreted also as a transport equation along rays of the wavefront Ωt in x-space associated with Ω. For a system of quasi-linear equations, the ray equations (which has two distinct parts) and the transport equation form a coupled system of underdetermined equations. As an example of this bicharacteristic formulation, we consider two-dimensional unsteady flow of an ideal magnetohydrodynamics gas with a plane aligned magnetic field. For any mode of propagation in this two-dimensional flow, there are three ray equations: two for the spatial coordinates x and y and one for the ray diffraction. In spite of little longer calculations, the final four equations (three ray equations and one transport equation) for the fast magneto-acoustic wave are simple and elegant and cannot be derived in these simple forms by use of a computer program like REDUCE.
Stellar models: firm evidence, open questions and future developments
Authors: Cassisi Santi
Published: April 2010

During this last decade our knowledge of the evolutionary properties of stars has significantly improved. This result has been achieved thanks to our improved understanding of the physical behavior of stellar matter in the thermal regimes characteristic of the different stellar mass ranges and/or evolutionary stages.

This notwithstanding, the current generation of stellar models is still affected by several, not negligible, uncertainties related to our poor knowledge of some thermodynamical processes and nuclear reaction rates, as well as the efficiency of mixing processes. These drawbacks have to be properly taken into account when comparing theory with observations, to derive evolutionary properties of both resolved and unresolved stellar populations.

In this paper we review the major sources of uncertainty along the main evolutionary stages, and emphasize their impact on population synthesis techniques.
The delay time distribution of type Ia supernovae: theory and observation
Authors: Vanbeveren Dany , Mennekens Nicki , De Greve Jean-Pierre , De Donder Erwin
Published: April 2010

Using a population number synthesis code, the theoretical time distributions of type Ia supernovae in starburst galaxies are calculated, using competing models for the formation of such events: the single degenerate (a white dwarf accreting matter from a late main sequence or red giant companion) and double degenerate (the merger of two white dwarfs) scenario. The code includes the latest results in determining the progenitors for both models. Examples are the mass stripping effect in the case of the single degenerate scenario and the differentiation between the α- (based on the balance of energy) and γ- (based on the balance of angular momentum) description of energy conversion during common envelope evolution of binaries. The shape and extent of the obtained delay time distributions critically depends on which formation scenario is used. Comparing these results to the latest observed distributions allows to draw conclusions about the constraints put on the theoretical models by these observations. We also specifically investigate the influence of the degree of conservatism during Roche lobe overflow on the delay time distribution. We conclude that the single degenerate scenario alone cannot reproduce the observed delay time distributions, and that most double degenerate type Ia supernovae are formed through a quasi-conservative Roche lobe overflow phase followed by spiral-in, as opposed to a double common envelope evolution.
Surface brightness fluctuations, tracers of stellar mass-loss?
Authors: González-Lópezlira Rosa A. , Bruzual-A. Gustavo , Charlot Stéphane , Ballesteros-Paredes Javier , Loinard Laurent
Published: April 2010

We present optical and IR integrated colors and SBF magnitudes, computed from stellar population synthesis models that include emission from the dusty envelopes surrounding mass-loosing TP-AGB stars. We explore the effects of varying the mass-loss rate by one order of magnitude around the fiducial value, modifying accordingly both the stellar parameters and the output spectra of the TP-AGB stars plus their dusty envelopes. We compare these models to optical and near-IR data of single AGB stars and Magellanic star clusters. Neither broad-band colors nor SBF measurements in the optical or the near-IR can discern global changes in the mass-loss rate of a stellar population. However, we predict that mid-IR SBF measurements can pick out such changes, and actually resolve whether a relation between metallicity and mass-loss exists.
The Future of Stellar Populations Studies in the Milky Way and the Local Group
Authors: Majewski Steven R.
Published: April 2010

The last decade has seen enormous progress in understanding the structure of the Milky Way and neighboring galaxies via the production of large-scale digital surveys of the sky like 2MASS and SDSS, as well as specialized, counterpart imaging surveys of other Local Group systems. Apart from providing snaphots of galaxy structure, these “cartographic” surveys lend insights into the formation and evolution of galaxies when supplemented with additional data (e.g., spectroscopy, astrometry) and when referenced to theoretical models and simulations of galaxy evolution. These increasingly sophisticated simulations are making ever more specific predictions about the detailed chemistry and dynamics of stellar populations in galaxies. To fully exploit, test and constrain these theoretical ventures demands similar commitments of observational effort as has been plied into the previous imaging surveys to fill out other dimensions of parameter space with statistically significant intensity. Fortunately the future of large-scale stellar population studies is bright with a number of grand projects on the horizon that collectively will contribute a breathtaking volume of information on individual stars in Local Group galaxies. These projects include: (1) additional imaging surveys, such as Pan-STARRS, SkyMapper and LSST, which, apart from providing deep, multicolor imaging, yield time series data useful for revealing variable stars (including critical standard candles, like RR Lyrae variables) and creating large-scale, deep proper motion catalogs; (2) higher accuracy, space-based astrometric missions, such as Gaia and SIM-Lite, which stand to provide critical, high precision dynamical data on stars in the Milky Way and its satellites; and (3) large-scale spectroscopic surveys provided by RAVE, APOGEE, HERMES, LAMOST, and the Gaia spectrometer, which will yield not only enormous numbers of stellar radial velocities, but extremely comprehensive views of the chemistry of stellar populations. Meanwhile, previously dust-obscured regions of the Milky Way will continue to be systematically exposed via large infrared surveys underway or on the way, such as the various GLIMPSE surveys from Spitzer's IRAC instrument, UKIDSS, APOGEE, JASMINE and WISE.
Early-type dwarf galaxies in the M81 group
Authors: Lianou Sophia , Grebel Eva K. , Koch Andreas
Published: April 2010

The M81 group is a highly interacting group consisting of a few large galaxies and about 40 dwarfs of both early- and late-type, thus making it an important nearby laboratory to study environmental effects and the role of interactions in the formation and evolution of dwarf galaxies. We are studying the resolved stellar populations of the early-type dwarf galaxies in this group with available HST/ACS data. We will show results on the metallicity distribution functions and on the potential presence of population gradients for these dwarf galaxies.
Dwarf Galaxies in the Local Group
Authors: Tolstoy Eline
Published: April 2010

Within the Local Universe galaxies can be studied in great detail star by star. The Color-Magnitude Diagram synthesis analysis method is well established as the most accurate way to determine the detailed star formation history of galaxies going back to the earliest times. This approach received a significant boost from the exceptional data sets that wide field CCD imagers on the ground and the Hubble Space Telescope could provide. Spectroscopic studies using large ground based telescopes such as VLT, Magellan, Keck and HET have allowed the determination of abundances and kinematics for significant samples of stars in nearby dwarf galaxies. These studies have shown directly how properties can vary spatially and temporally, which gives important constraints to theories of galaxy formation and evolution.
Ground-based proper motions of nearby local group galaxies: A progress report for Fornax
Authors: Méndez Rene A. , Costa Edgardo , Pedreros Mario H. , Moyano Maximiliano , Altmann Martin , Gallart Carme
Published: April 2010

Determining the kinematics of the dwarf Spheroidal galaxies (dSph) satellites of the Milky Way (MW) is crucial to estimate the mass of our galaxy, to understand its formation process and that of its satellites, to explain the origin of stellar streams in the MW's halo that seem to be related to these satellites, and to understand the role of tidal interactions in the evolution and star formation history of low mass galaxies and of the halo of our Galaxy. In what follows we briefly explain a ground-based astrometric project that will have an impact on these issues, and present some preliminary results.
An analysis of the composite stellar population in M32
Authors: Coelho P. , Mendes de Oliveira C. , Cid Fernandes R.
Published: April 2010

We obtained long-slit spectra of high S/N of the galaxy M32 with the GMOS Spectrograph at the Gemini-North telescope. We analysed the integrated spectra by means of spectral fitting in order to extract the mixture of stellar populations that best represents its composite nature. As our main result, we propose that an ancient and an intermediate-age population co-exist in M32, and that the balance between these two populations change between the nucleus and outside one effective radius (1reff) in the sense that the contribution from the intermediate population is larger at the nuclear region. We retrieve a smaller signal of a young population at all radii whose origin is unclear, and may be a contamination from horizontal branch stars, blue stragglers or a true young population previously unidentified (Monachesi et al., this volume). We compare our metallicity distribution function for a region 1 to 2 arcmin from the centre to the one obtained with photometric data by Grillmair et al. Both distributions are broad, but our spectroscopically derived distribution has a significant component with [Z/Z⊙] ≤ −1, which is not found by Grillmair et al.
What drives the star formation in early-type galaxies at late epochs? - the case for minor mergers
Authors: Kaviraj Sugata , Ellis Richard , Yi Sukyoung , Silk Joseph , Schawinski Kevin , Gawiser Eric , van Dokkum Pieter , Urry C. Megan
Published: April 2010

Multi-wavelength photometry of early-type galaxies (ETGs) in the COSMOS survey is used to demonstrate that the low-level star formation activity in the ETG population at late epochs (z < 1) is likely to be driven by repeated minor mergers. While relaxed ETGs are almost entirely contained within the UV red sequence, their morphologically disturbed counterparts are largely found in the blue cloud, regardless of luminosity. Since empirically determined major-merger rates in the redshift range z < 1 are a few factors too low to account for the number fraction of disturbed ETGs, this suggests that minor mergers are the principal mechanism that drives star formation activity in ETGs at low and intermediate redshift.
Ecology of galaxy stellar populations from optical spectroscopic surveys
Authors: Gallazzi Anna
Published: April 2010

The age and chemical composition of the stars in present-day galaxies carry important clues about their star formation processes. The latest generation of population synthesis models have allowed to derive age and stellar metallicity estimates for large samples of low-redshift galaxies. After reviewing the main results about the distribution in ages and metallicities as a function of galaxy mass, I will concentrate on recent analysis that aims at disentangling the dependences of stellar populations properties on environment and on galaxy stellar mass. Finally, new models that predict the response of the full spectrum to variations in [α/Fe] will allow us to derive accurate estimates of elements abundance ratios and gain deeper insight into the timescales of star formation cessation.
Stellar populations of local infrared-selected galaxies
Authors: Chen X. Y. , Liang Y. C. , Hammer F. , Zhao Y. H. , Zhong G. H.
Published: April 2010

The stellar populations of 849 local infrared-selected galaxies from SDSS and IRAS (including 419 star-forming galaxies, 326 composite galaxies, 35 Seyfert 2s, and 69 LINERs in 4 spectral classes) are studied by using STARLIGHT. Among the 4 spectral classes, the importance of young populations decreases from star-forming, composite, Seyfert 2 to LINER; and Seyfert 2 and LINER are more metal-rich; ULIGs (ultra luminous infrared galaxies) & LIGs present the youngest populations among 3 infrared luminosity bins; and normal galaxies are more metal-rich. The dominant contributors to masses are all old populations.
Automated morphological classification of galaxies using wavelet transform
Authors: Curty Didier , Cuisinier François C. , Rabaça Carlos R.
Published: April 2010

The wavelet transform acts to segregate objects in function of their size. We apply this method on images of galaxies to decompose them into coefficients representing only objects of the same size. The total fluxes of the wavelet coefficients describe the cumulative power spectrum of spatial frequencies. Based on this spectrum, we propose a new parameter to quantify the galaxy texture. As expected, it remains small and quite invariant for early-type galaxies, while it covers a large range and takes larger values for late-type galaxies. Combined with a second parameter, our determination of the texture is able to successfully separate galaxy types. By thresholding the wavelet coefficients, we detect luminous lumps. In irregular galaxies, their radial distribution seems to show a double peak. This could be the trace of a privileged radial distance of strong star formation regions.
Empirical tests of evolutionary synthesis models
Authors: Gomes Jean Michel , Cid Fernandes R.
Published: April 2010

Spectral synthesis of stellar populations has proven to be one of the most powerful methods to decompose the different mixtures of stellar contributions in galaxies, and applications of this technique routinely appear in the literature nowadays. Our group, for instance, the SEAGal (Semi Empirical Analysis of Galaxies) collaboration, has derived the star formation history of all galaxies in the SDSS with the starlight code, obtaining various results of astrophysical interest. As any other fossil method, the results rely heavily on high spectral resolution evolutionary synthesis models. To test this model dependence we run starlight on samples of star-forming and passive galaxies from the SDSS using different sets of models.

We explore models using “Padova 1994” and modified “Padova” evolutionary tracks with a different receipt for the asymptotic giant branch phase, as well as different stellar libraries (STELIB versus MILES+Granada). We then compare derived properties such as mean age, mean metallicity, extinction, star-formation and chemical histories. Despite a broad brush agreement, systematic differences emerge from this comparison. The different evolutionary tracks used lead to essentially the same results, at least insofar as optical spectra are concerned. Different stellar libraries, on the other hand, have a much bigger impact. The newer models produce quantifiably better fits and eliminate some pathologies (like suspicious combinations of base elements, systematical spectral residuals in some windows, and, sometimes, negative extinction) of fits derived with STELIB-based models, but there are still some caveats. These empirical tests provide useful feedback for model makers.
On Star Formation in TDC
Authors: Hojaev A. S. , Nuritdinov S. N.
Published: April 2010

The value of different forms of energy contained in TDC region as well as the structure and physical characteristics of star formation in the Taurus Dark Clouds are analyzed.
Tracers of Star Formation in the Near Infrared
Authors: Martins L. , Ardila A. , Gruenwald R. , de Souza R.
Published: April 2010

Starburst features in the optical are nowadays well known, but the use of this knowledge is not always possible (e.g. objects heavily obscured). In this case the near-IR is of unprecedented value. Recent models show that TP-AGB stars should dominate the NIR spectra of populations 0.3 to 2 Gyr old. While the optical spectra is insensitive to the presence of these stars, the near-IR changes dramatically. Not only does the absolute flux in the near-IR is affected, but also peculiar absorption features appear. These features can be used as indicators of 1 Gyr stellar population. In this work we used the IRTF Spex to create the first empirical database of NIR spectra of carefully selected starbursts, to test for the first time and in a consistent way the new stellar population models that account for the TP-AGB. The methodology used is to do stellar population synthesis in the optical and in the NIR, and compare the predictions of both spectral regions. We also compare the strength of important features of the TP-AGB stars, like the CN (1.1 microns) and CO (2.3 microns) bands with optical diagnostics.
Detailed Abundances for Field Stars Surrounding the LMC Cluster Hodge 11
Authors: Mateluna Renee , Geisler Douglas , Villanova Sandro
Published: April 2010

We present results of a detailed model atmosphere abundance analysis for a variety of elements, including Fe, Ca, Si, Ti, Sc, Ni, Cr and Ba for a number of giants in the surrounding field of the LMC cluster H11, obtained from high resolution FLAMES@VLT spectra.
The interacting binary V 393 Scorpii: another clue for Double Periodic Variables
Authors: Mennickent Ronald , Kołaczkowski Zbigniew , Djurasevic Gojko , Michalska Gabriela , Barría Daniela
Published: April 2010

We give a brief report on spectroscopic properties of V 393 Scorpii. Hα emission and shape and radial velocity of He I5875 are modulated with the long cycle. The long cycle is explained as a relaxation cycle in the circumprimary disc, that cumulates the mass transferred from the donor until certain instability produces disc depletion.
The Mg/Fe characterization of the MILES library for stellar populations studies
Authors: Milone André , Sansom Anne E. , Sánchez-Blázquez Patricia
Published: April 2010

We have obtained [Mg/Fe] for around 77% of the stars of the MILES library of stellar spectra in order to include this important information into simple stellar population (SSP) models. The abundance ratios, which were carefully calibrated to a single uniform scale, were obtained through a compilation from high spectral resolution works plus robust spectroscopic analysis at medium resolution. The high resolution data provided an extensive control sample. Average uncertainties (0.06 and 0.12 dex for the high and medium resolution samples respectively) and the good coverage of the stars with [Mg/Fe] over the MILES's parameter space will permit us to semi-empirically build up new SSP models with accurate α-enhancements for ages older than 1 Gyr. This will open new prospects for evolutionary stellar population synthesis.
Baryons and Dark Matter halo distributions in ΛCDM Cosmology
Authors: Pedrosa Susana , Tissera Patricia , Scannapieco Cecilia
Published: April 2010

We analyse the dark matter (DM) distribution in a ≈1012M⊙ halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. Although the DM profiles get more concentrated as baryons are collected at the centre of the haloes compared to a pure dynamical run, the total baryonic mass alone is not enough to fully predict the reaction of the DM profile. Our findings suggest that the response of the DM halo is driven by the history of assembly of baryons into a galaxy. The accretion of satellites could be associated with an expansion of the dark matter profiles, triggered by angular momentum transfer from the incoming satellites. However, we also found that these mechanism have different efficiencies which are set by the history of formation of the structure.
Evolution of Stellar Population: Environments vs galaxy interactions
Authors: Perez Josefa , Tissera Patricia , Padilla Nelson , Alonso Sol , Lambas Diego G.
Published: April 2010

Several authors have studied the dependence of galaxy properties on environment in order to understand which mechanisms operate in the galaxy evolution. Recently, some of them have proposed that intermediate densities could be sites where local environment influences the transition of galaxies onto the red-sequence, as opposed to mechanisms that operate on cluster scales. Based on the evidence that interacting and merging systems are frequent at intermediate densities, we use the SDSS-DR4 data to analyse the role of close galaxy interactions as an environmental process which could contribute to lead evolutionary transformations. We explore the properties of galaxy pairs at different local and global density environments, comparing them with those of isolate galaxies in an unbiased control sample (CS).
Probing Stellar Mass Assembly in the Virgo Cluster
Authors: Roediger Joel C. , Courteau Stéphane , McDonald Michael , MacArthur Lauren A.
Published: April 2010

We have examined in detail both the resolved and integrated stellar content of a representative sample of galaxies in the Virgo cluster to constrain plausible formation/evolution scenarios for them. Systematic variations in age and metallicity gradients along the Hubble sequence are found such that the gradients become more negative for later types. Combined with correlations of the above stellar properties with both structure and environment, these data highlight the significance of merging in the assembly of massive spheroids and environmental phenomena (gas removal/interactions) in the evolution of disks and dwarf systems. Our data also provide useful perspectives on a number of important topics in the recent literature.
Galaxy disc heating as a result of minor mergers
Authors: Tapia M. T. , Balcells M. , Eliche-Moral M. C.
Published: April 2010

We perform a sample of N-body simulations of a minor merger between a Milky Way type galaxy and a satellite, which is density scaled version of the primary galaxy. In this suite of collisionless runs we change the value of some critical parameters like the luminous mass ratio between the two galaxies (1 : 6, 1 : 9), the type of orbit (direct or prograde) and the number of particles (185,000, 555,000 and 1,850,000). We estimate the disc thickening by measuring the median of the vertical scale and we find that that the merger increases the scale height in a factor of ≈2 in all the remnants.
Erfassung von Metakognitionen bei Zwangsstörungen
Authors: Neumann Angelika , Reinecker Hans , Geissner Edgar
Published: April 2010

Zusammenfassung. In der vorliegenden Studie wurde ein Fragebogen („Zwangsassoziierte Gedanken und Gefühle”) entwickelt, welcher Metakognitionen bei Zwang nach nach dem S-Ref-Modell nach Wells misst. Mittels Faktorenanalysen wurden psychometrische Eigenschaften überprüft (Studie 1, n = 215 Zwangserkrankte). 5 Dimensionen erwiesen sich als plausibel, konsistent und reliabel: (1) Wertlosigkeit, (2) Kontrolle, (3) Zweifel, (4) Toleranz und (5) Gelassenheit. In Studie 2 wurde der Fragebogen auf Validität, Spezifität und Änderungssensitivität überprüft (40 Zwangspatienten; 40 Depressive; 40 Patienten mit Agoraphobie; 55 Zwangspatienten mit komorbider Depression und 39 gesunde Personen). Die Skalen Wertlosigkeit, Kontrolle und Zweifel zeigten klare Gruppenunterschiede: gesunde Personen hatten die niedrigsten Werte, gefolgt von den Personen mit Agoraphobie. Depressive und Zwangspatienten unterschieden sich von diesen deutlich, jedoch wider Erwarten nicht untereinander. Die Skala Wertlosigkeit und die Skala Schuld korrelierten substanziell mit anderen Maßen der Zwangsdiagnostik, ferner mit Ängstlichkeit und Depressivität.
Bildschirmmedien im Kindergartenalter
Authors: Maaß Enno Edo , Hahlweg Kurt , Heinrichs Nina , Kuschel Annett , Döpfner Manfred
Published: April 2010

Zusammenfassung. Die vorliegende Querschnittsuntersuchung (N = 708 Familien) versuchte unter Berücksichtigung wichtiger Kovariaten wie z.B. des elterlichen Erziehungsverhaltens oder sozioökonomischer Variablen Zusammenhänge zwischen der Nutzung elektronischer Medien, Verhaltensauffälligkeiten und ADHS zu identifizieren. Nach der SÖS (sozioökonomischer Status) – Mainstreaming Hypothese würden die stärksten Zusammenhänge für Kinder mit hohem SÖS erwartet, währenddessen nach der SÖS-Resonanz Hypothese diese vor allem für Kinder mit niedrigem SÖS erwartet werden würden. Ergebnisse: Es zeigten sich signifikante Zusammenhänge zwischen der täglichen Fernsehnutzung und vermehrten Schlafproblemen, aggressivem Verhalten sowie Aufmerksamkeitsproblemen. Eine tägliche Computernutzung wies hingegen einen Zusammenhang mit geringeren Aufmerksamkeitsproblemen auf. In Abhängigkeit des SÖS der Mütter folgten die Zusammenhänge (v.a.) hinsichtlich der Fernsehnutzung und internalisierendem Verhalten in gewissem Maße den Vorhersagen einer Resonanz-Hypothese, währenddessen in Abhängigkeit des SÖS der Väter diese eher einer Mainstreaming-Hypothese entsprachen. Zukünftige Forschungsarbeiten können profitieren, wenn diese Moderationen im Untersuchungsdesign stärker berücksichtigt würden.
Neutral wind and plasma drift effects on low and middle latitude total electron content
Authors: Shim J. S. , Scherliess L. , Schunk R. W. , Thompson D. C.
Published: April 2010

A physics‐based numerical ionosphere/plasmasphere model (IPM) was used to study the effects of daytime neutral wind and electric field perturbations on the subsequent evolution of the afternoon and postsunset total electron content (TEC) during vernal equinox conditions. The model solves the transport equations for six ions on convecting flux tubes that realistically follow the geomagnetic field. The IPM covers geomagnetic latitudes from about 60°N to 60°S and equatorial crossing altitudes from 90 to 30,000 km. Two of the input parameters required by the IPM are the thermospheric neutral wind and the low‐latitude electric field, which can be provided by existing empirical models or externally specified. To study effects of the neutral winds and the electric fields on TEC, these two model inputs were externally modified, and the resulting TEC variations were compared. Neutral wind and electric field modifications were introduced at three different local times in order to investigate the effect of different perturbation times on the evolution of TEC. Three longitudes (78°E, 273°E, and 318°E) were considered, and the results correspond to conditions of medium solar activity and low geomagnetic activity. The largest TEC changes were found predominantly in the equatorial anomaly, and a significant longitudinal dependence was observed. The simulation results indicate that TEC variations at 2100 LT vary nonlinearly at low latitudes and linearly at middle latitudes with the elapsed time after the imposed perturbations. An important outcome of this study is that daytime neutral wind and/or electric field modifications can lead to essentially identical TEC changes at 2100 LT.
On the consistency of model, ground‐based, and satellite observations of tidal signatures: Initial results from the CAWSES tidal campaigns
Authors: Ward W. E. , Oberheide J. , Goncharenko L. P. , Nakamura T. , Hoffmann P. , Singer W. , Chang L. C. , Du J. , Wang D.‐Y. , Batista P. , Clemesha B. , Manson A. H. , Riggin D. M. , She C.‐Y. , Tsuda T. , Yuan T.
Published: April 2010

Comparisons between tidal wind signatures diagnosed from satellite and ground‐based observations and a general circulations model for two (September–October 2005, March–April 2007) of the four Climate and Weather of the Sun‐Earth System (CAWSES) Global Tidal Campaign observation periods are presented (CAWSES is an international program sponsored by Scientific Committee on Solar‐Terrestrial Physics). Specific comparisons are made between model (extended Canadian Middle Atmosphere Model), satellite (Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)), meteor, MF and incoherent scatter radar (ISR), and lidar tidal signatures in the mesosphere and lower thermosphere. The satellite and ground‐based signatures are in good agreement and demonstrate for the first time that the tidal wind fields observed by both types of observations are consistent with each other. This is the first time that such agreement has been reported and effectively resolves the long‐standing issue between ground‐based radar and satellite optical measurements of winds. This level of agreement, which has proved elusive in the past, was accomplished by superposing the significant tidal components from the satellite analyses to reconstruct the fields observed by the ground stations. Particularly striking in these comparisons is the extent to which the superposed fields show strong geographic variability. This variability is also seen in the component superpositions generated from the extended Canadian Middle Atmosphere Model (eCMAM), although differences in the geographic patterns are evident.