Are the school prevention programmes - aimed at de-normalizing smoking among youths - beneficial in the long term? An example from the Smoke Free Class Competition in Italy

Tobacco smoking by young people is of great concern because it usually leads to regular smoking, nicotine addiction and quitting difficulties. Young people "hooked" by tobacco maintain the profits of the tobacco industry by replacing smokers who quit or die. If new generations could be tobacco-free, as supported by tobacco endgame strategies, the tobacco epidemic could end within decades. Smoking prevention programmes for teens are offered by schools with the aim to prevent or delay smoking onset. Among these, the Smoke Free Class Competition (SFC) was widely implemented in Europe. Its effectiveness yielded conflicting results, but it was only evaluated at short/medium term (6 - 18 months). The aim of this study is to evaluate its effectiveness after a longer follow-up (3 to 5 years) in order to allow enough time for the maturing of the students and the internalization of the experience and its contents. Fifteen classes were randomly sampled from two Italian high schools of Bologna province that regularly offered the SFC to first year students; 382 students (174 participating in the SFC and 208 controls) were retrospectively followed-up and provided their "smoking histories". At the end of their last year of school (after 5 years from the SFC), the percentage of students who stated that they were regular smokers was lower among the SFC students than in controls: 13.5% vs 32.9% (p=0.03). From the students' "smoking histories", statistically significant protective ORs were observed for SFC students at the end of 1st and 5th year: 0.42 (95% CI 0.19-0.93) and 0.32 (95% CI 0.11-0.91) respectively. Absence of smokers in the family was also a strongly statistically significant factor associated with being a non-smoker student. These results suggest that SFC may have a positive impact on lowering the prevalence of smoking in the long term (5 years)

Fabry-Perot observations of the HH 110 jet

We have obtained a Halpha position-velocity cube from Fabry-Perot interferometric observations of the HH 110 flow. We analyze the results in terms of anisotropic wavelet transforms, from which we derive the spatial distribution of the knots as well as their characteristic sizes (along and across the outflow axis). We then study the spatial behaviour of the line width and the central radial velocity. The results are interpreted in terms of a simple ``mean flow+turbulent eddy'' jet/wake model. We find that most of the observed kinematics appear to be a direct result of the mean flow, on which are superposed low amplitude (35 km/s) turbulent velocities.Comment: 27 pages, 8 Postscript figures. Astronomical Journal (accepted

Integral field spectroscopy with SINFONI of VVDS galaxies. II. The mass-metallicity relation at 1.2 < z < 1.6

This work aims to provide a first insight into the mass-metallicity (MZ) relation of star-forming galaxies at redshift z~1.4. To reach this goal, we present a first set of nine VVDS galaxies observed with the NIR integral-field spectrograph SINFONI on the VLT. Oxygen abundances are derived from empirical indicators based on the ratio between strong nebular emission-lines (Halpha, [NII]6584 and [SII]6717,6731). Stellar masses are deduced from SED fitting with Charlot & Bruzual (2007) population synthesis models, and star formation rates are derived from [OII]3727 and Halpha emission-line luminosities. We find a typical shift of 0.2-0.4 dex towards lower metallicities for the z~1.4 galaxies, compared to the MZ-relation in the local universe as derived from SDSS data. However, this small sample of eight galaxies does not show any clear correlation between stellar mass and metallicity, unlike other larger samples at different redshift (z~0, z~0.7, and z~2). Indeed, our galaxies lie just under the relation at z~2 and show a small trend for more massive galaxies to be more metallic (~0.1 logarithmic slope). There are two possible explanations to account for these observations. First, the most massive galaxies present higher specific star formation rates when compared to the global VVDS sample which could explain the particularly low metallicity of these galaxies as already shown in the SDSS sample. Second, inflow of metal-poor gas due to tidal interactions could also explain the low metallicity of these galaxies as two of these three galaxies show clear signatures of merging in their velocity fields. Finally, we find that the metallicity of 4 galaxies is lower by ~0.2 to 0.4 dex if we take into account the N/O abundance ratio in their metallicity estimate.Comment: 7 pages, 4 figures, accepted in A&A Comments: Comments: more accurate results with better stellar mass estimate

MASSIV: Mass Assembly Survey with SINFONI in VVDS. VI. Metallicity-related fundamental relations in star-forming galaxies at 1<z<21 < z < 2

The MASSIV (Mass Assembly Survey with SINFONI in VVDS) project aims at finding constraints on the different processes involved in galaxy evolution. This study proposes to improve the understanding of the galaxy mass assembly through chemical evolution using the metallicity as a tracer of the star formation and interaction history. Methods. We analyse the full sample of MASSIV galaxies for which a metallicity estimate has been possible, that is 48 star-forming galaxies at $z\sim 0.9-1.8$, and compute the integrated values of some fundamental parameters, such as the stellar mass, the metallicity and the star formation rate (SFR). The sample of star-forming galaxies at similar redshift from zCOSMOS (P\'erez-Montero et al. 2013) is also combined with the MASSIV sample. We study the cosmic evolution of the mass-metallicty relation (MZR) together with the effect of close environment and galaxy kinematics on this relation. We then focus on the so-called fundamental metallicity relation (FMR) proposed by Mannucci et al. (2010) and other relations between stellar mass, SFR and metallicity as studied by Lara-L\'opez et al. (2010). We investigate if these relations are really fundamental, i.e. if they do not evolve with redshift. Results. The MASSIV galaxies follow the expected mass-metallicity relation for their median redshift. We find however a significant difference between isolated and interacting galaxies as found for local galaxies: interacting galaxies tend to have a lower metallicity. The study of the relation between stellar mass, SFR and metallicity gives such large scattering for our sample, even combined with zCOSMOS, that it is diffcult to confirm or deny the existence of a fundamental relation

Candidate tidal dwarf galaxies associated with the Stephan's Quintet

We present kinematic and photometric evidence for the presence of seven candidate tidal dwarf galaxies in Stephan's quintet. The central regions of the two most probable parent galaxies, N7319 and N7318B, contain little or no gas whereas the intragroup medium, and particularly the optical tails that seem to be associated with N7318B are rich in cold and ionized gas. Two tidal-dwarf candidates may be located at the edge of a tidal tail, one within a tail and for four others there is no obvious stellar/gaseous bridge between them and the parent galaxy. Two of the candidates are associated with HI clouds, one of which is, in addition, associated with a CO cloud. All seven regions have low continuum fluxes and high H$\alpha$ luminosity densities (F(H$\alpha$) = 1 -- 60 $\times$ 10$^{-14}$ erg s$^{-1}$ cm$^{-2}$). Their magnitudes (M$_B =$ --16.1 to --12.6), sizes ($\sim$ 3.5 h$_{75}^{-1}$ kpc), colors (typically $B-R = 0.7$) and gas velocity gradients ($\sim$ 8 -- 26 h$_{75}$ km s$^{-1}$ kpc$^{-1}$) are typical for tidal dwarf galaxies. In addition the ratios between their star formation rates determined from H$\alpha$ and from the B band luminosity are typical of other tidal dwarf galaxies. The masses of the tidal dwarf galaxies in Stephan's quintet range from $\sim$ 2 $\times$ 10$^8$ to 10$^{10}$ M$_\odot$ and the median value for their inferred mass-to-light ratios is 7 M$_\odot$/L$_\odot$.Comment: Accepted for publication in Astronomical Journal (23p 11figures

The Power of Non-Determinism in Higher-Order Implicit Complexity

We investigate the power of non-determinism in purely functional programming languages with higher-order types. Specifically, we consider cons-free programs of varying data orders, equipped with explicit non-deterministic choice. Cons-freeness roughly means that data constructors cannot occur in function bodies and all manipulation of storage space thus has to happen indirectly using the call stack. While cons-free programs have previously been used by several authors to characterise complexity classes, the work on non-deterministic programs has almost exclusively considered programs of data order 0. Previous work has shown that adding explicit non-determinism to cons-free programs taking data of order 0 does not increase expressivity; we prove that this - dramatically - is not the case for higher data orders: adding non-determinism to programs with data order at least 1 allows for a characterisation of the entire class of elementary-time decidable sets. Finally we show how, even with non-deterministic choice, the original hierarchy of characterisations is restored by imposing different restrictions.Comment: pre-edition version of a paper accepted for publication at ESOP'1

N-body simulations of galaxies and groups of galaxies with the Marseille GRAPE systems

I review the Marseille GRAPE systems and the N-body simulations done with them. I first describe briefly the available hardware and software, their possibilities and their limitations. I then describe work done on interacting galaxies and groups of galaxies. This includes simulations of the formation of ring galaxies, simulations of bar destruction by massive compact satellites, of merging in compact groups and of the formation of brightest members in clusters of galaxies.Comment: 13 pages, 5 figures, to be published in "Non-linear Dynamics and Chaos in Astrophysics", eds. J.R. Buchler, S. Gottesman, J. Hunter and H. Kandrup, Annals of the New York Academy of Science

The detection of non-thermal radio continuum spokes and the study of star formation in the Cartwheel

New sensitive Very Large Array 20 cm continuum observations of the Cartwheel, the prototypical collisional ring galaxy, were carried out with the principal aim of tracing supernova remnants that are expected to lie in the wake of the expanding ring and in the ring itself. We detect predominantly non-thermal radio continuum emission from regions associated with 13 ring HII complexes. The emission interior to the ring is confined to structures that resemble spokes of the wheel. The spokes start near bright HII complexes, and extend to around 6 arcsec (4 kpc) inward in the direction of the geometrical center of the ring. There is no apparent positional coincidence between the radio continuum and optical spokes. Radial distribution of intensity along the spokes suggests that the past star formation rate (SFR) in the Cartwheel was much lower than the current SFR. New Halpha observations were used to revise the current SFR in the Cartwheel. The revised value is 18 Msun/yr, which is a factor of 4 lower than the value reported previously, but is in good agreement with the SFR estimated from far infrared luminosity. About 30% of the observed 20 cm continuum non-thermal emission seems to originate in processes that are not related to star formation. Revised SFR in the Cartwheel is comparable to that in the rest of the ring galaxies.Comment: 6 pages, uses emulateapj.cls. Scheduled to appear in ApJL February 10, 200