Star Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of "Transition" Galaxies

We present new H-alpha narrow band imaging of the HII regions in eight Sculptor Group dwarf irregular (dI) galaxies. Comparing the Sculptor Group dIs to the Local Group dIs, we find that the Sculptor Group dIs have, on average, lower values of SFR when normalized to either galaxy luminosity or gas mass (although there is considerable overlap between the two samples). The properties of ``transition'' (dSph/dIrr) galaxies in Sculptor and the Local Group are also compared and found to be similar. The transition galaxies are typically among the lowest luminosities of the gas rich dwarf galaxies. Relative to the dwarf irregular galaxies, the transition galaxies are found preferentially nearer to spiral galaxies, and are found nearer to the center of the mass distribution in the local cloud. While most of these systems are consistent with normal dI galaxies which currently exhibit temporarily interrupted star formation, the observed density-morphology relationship (which is weaker than that observed for the dwarf spheroidal galaxies) indicates that environmental processes such as ``tidal stirring'' may play a role in causing their lower SFRs.Comment: 35 pages, 10 figures, accepted for Feb 2003 AJ, companion to astro-ph/021117

Star Formation in Dwarf Galaxies of the Nearby Centaurus A Group

We present Halpha narrow-band imaging of 17 dwarf irregular galaxies (dIs) in the nearby Centaurus A Group. Although all large galaxies of the group have a current or recent enhanced star formation episode, the dIs have normal star formation rates and do not contain a larger fraction of dwarf starbursts than other nearby groups. Relative distances between dIs and larger galaxies of the group can be computed in 3D since most of them have now fairly accurately known distances. We find that the dI star formation rates do not depend on local environment, and in particular they do not show any correlation with the distance of the dI to the nearest large galaxy of the group. There is a clear morphology-density relation in the Centaurus A Group, similarly to the Sculptor and Local Groups, in the sense that dEs/dSphs tend to be at small distances from the more massive galaxies of the group, while dIs are on average at larger distances. We find four transition dwarfs in the Group, dwarfs that show characteristics of both dE/dSphs and dIs, and which contain cold gas but no current star formation. Interestingly the transition dwarfs have an average distance to the more massive galaxies which is intermediate between those of the dEs/dSphs and dIs, and which is quite large: 0.54 +- 0.31 Mpc. This large distance poses some difficulty for the most popular scenarios proposed for transforming a dI into a dE/dSph (ram-pressure with tidal stripping or galaxy harassment). If the observed transition dwarfs are indeed missing links between dIs and dE/dSphs, their relative isolation makes it less likely to have been produced by these mechanisms. We propose that an inhomogeneous IGM containing higher density clumps would be able to ram-pressure stripped the dIs at such large distances.Comment: 57 pages, 10 fi5gure

Chemical Abundances of Seven Irregular and Three Tidal Dwarf Galaxies in the M81 Group

We have derived nebular abundances for 10 dwarf galaxies belonging to the M81 Group, including several galaxies which do not have abundances previously reported in the literature. For each galaxy, multiple H \ii regions were observed with GMOS-N at the Gemini Observatory in order to determine abundances of several elements (oxygen, nitrogen, sulfur, neon, and argon). For seven galaxies, at least one H \ii region had a detection of the temperature sensitive [OIII] $\lambda$4363 line, allowing a "direct" determination of the oxygen abundance. No abundance gradients were detected in the targeted galaxies and the observed oxygen abundances are typically in agreement with the well known metallicity-luminosity relation. However, three candidate "tidal dwarf" galaxies lie well off this relation, UGC 5336, Garland, and KDG 61. The nature of these systems suggests that UGC 5336 and Garland are indeed recently formed systems, whereas KDG 61 is most likely a dwarf spheroidal galaxy which lies along the same line of sight as the M81 tidal debris field. We propose that these H \ii regions formed from previously enriched gas which was stripped from nearby massive galaxies (e.g., NGC 3077 and M81) during a recent tidal interaction.Comment: 37 pages, 10 figures, accepted for publication in ApJ. Slit positions in Table 2 have been update

Climate Security Investment Planning: A methodology to co-develop investments with climate action and peacebuilding objectives

Finance for climate action can be an important means of bolstering the resilience of communities exposed to climate hazards, addressing developmental challenges, and redistributing wealth toward the Global South. However, investments in contexts where climate and conflict risks overlap must recognize linkages between the two and be careful not to cause or worsen violence. More aspirationally, they should leverage food, land, and water systems to build peace by fostering positive social conditions. Toward that goal, this document articulates a process to identify, co-develop, and deploy integrated climate security investments

Navigating a river by its bends. A study on transnational social networks as resources for the transformation of Cambodia

This article explores in what ways first generation Cambodian French and Cambodian American returnees create and employ the social capital available in their transnational social networks upon their return to Cambodia. The triangular interdependence between the returnees, their overseas immigrant communities and homeland society is taken as a starting point. The central argument is that Cambodian French and Cambodian American returnees build different relationships to Cambodia due to: (1) the influence of their immigrant communities in the countries of resettlement; and (2) the contexts of their exit from Cambodia. Regarding debates on the contribution of returnees to an emergent nation, findings in this multisited casestudy bring forward that ideas of return held by the three parties involved may force remigrants into transnationalism in both host and home countries. Findings also demonstrate that social capital may be seen as a resource or a restraint in the lives of returnees

Genetic architecture of subcortical brain structures in 38,851 individuals

Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease

Development of turbulent scheme in the FLEXPART-AROME v1.2.1 Lagrangian particle dispersion model

International audienceThe FLEXible PARTicle dispersion model FLEX-PART, first released in 1998, is a Lagrangian particle dispersion model developed to simulate atmospheric transport over large and mesoscale distances. Due to FLEXPART's success and its open source nature, different limited area model versions of FLEXPART were released making it possible to run FLEXPART simulations by ingesting WRF (Weather Research Forecasting model), COSMO (Consor-tium for Small-scale Modeling) or MM5 (mesoscale community model maintained by Penn State university) meteorological fields on top of the ECMWF (European Centre for Medium-Range Weather Forecasts) and GFS (Global Forecast System) meteorological fields. Here, we present a new FLEXPART limited area model that is compatible with the AROME mesoscale meteorological forecast model (the Applications of Research to Operations at Mesoscale model). 1 FLEXPART-AROME was originally developed to study mesoscale transport around La Réunion, a small volcanic island in the southwest Indian Ocean with a complex orographic structure, which is not well represented in current global operational models. We present new turbulent modes in FLEXPART-AROME. They differ from each other by dimensionality, mixing length parameterization, turbulent transport constraint interpretation and time step configuration. A novel time step was introduced in FLEXPART-AROME. Performances of new turbulent modes are compared to the ones in FLEXPART-WRF by testing the conservation of well-mixedness by turbulence, the dispersion of a point release at the surface and the marine boundary layer evolution around Réunion. The novel time step configura-1 Applications de la Recherche à l'Opérationnel à Méso-Echelle. tion proved necessary to conserve the well-mixedness in the new turbulent modes. An adaptive vertical turbulence time step was implemented, allowing the model to adapt on a finer timescale when significant changes in the local turbulent state of the atmosphere occur

Retour sur le concept de maturité dans le contexte du désistement de la délinquance durant la transition adolescence-vie adulte

La criminologie des parcours de vie concernant le désistement de la délinquance a fourni peu de lignes directrices quant aux stratégies d’intervention visant les jeunes adultes. Étant donné le caractère dynamique de la maturité ainsi que de la délinquance à ce stade de développement, la présente étude propose un regard sur le concept de maturité et son impact possible sur le processus de désistement. Bien mettre en évidence les aspects spécifiques de la maturité qui sont importants pour le désistement de la délinquance peut aider les intervenants à déterminer de quelle façon ils peuvent contribuer au processus de désistement lorsqu’ils travaillent auprès de clients plus jeunes pour qui les points tournants traditionnels tels que le mariage et l’emploi ne sont pas nécessairement immédiatement accessibles, voire même pertinents pour ce groupe d’âge. La présente étude s’appuie sur des données concernant les individus de sexe masculin interviewés dans le cadre de l’étude longitudinale Pathways to Desistance Study qui étaient âgés de 16 ou 17 ans au début de l’étude (n = 704). Une série d’analyses statistiques à effets fixes montre que des changements intra-individuels sur le plan de la maturité sont associés à un ralentissement de la délinquance autorapportée. En particulier, les résultats de l’étude mettent en évidence l’importance des changements sur le plan identitaire et psychosocial ainsi qu’une plus grande ouverture quant à l’adoption d’un statut d’adulte. Les stratégies d’intervention qui aident au développement de ces aspects de la maturité sont plus susceptibles de favoriser le processus de désistement d’une clientèle de jeunes adultes.Life course criminology research on desistance has not provided practitioners with much direction about effective areas of focus for intervention strategies, especially during adolescence and emerging adulthood. This gap can be addressed by considering how maturation, an important part of this developmental period, influences desistance. The current study focused on males from the Pathways to Desistance Study who were aged 16 or 17 at baseline (n = 704). Fixed-effects models showed that within-individual increases in psychosocial and identity measures of maturation were associated with within-individual decreases in a person’s self-reported level of offending. The findings highlight the value of intervention and treatment strategies that improve maturation.La investigación en criminología sobre las trayectorias de vida que se enfoca en el desistimiento no ha brindado a los profesionales muchas directivas en lo que tiene que ver con áreas centrales para las estrategias de intervención, especialmente durante la adolescencia y la adultez emergente. Esto puede ser abordado, considerando cómo la madurez, que es una parte importante de este período de desarrollo, influencia el desistimiento. El presente estudio se enfoca en hombres del estudio “caminos hacia el desistimiento”, que tenían 16 o 17 al principio (n = 704). Los modelos de efectos fijos mostraron que los aumentos intra-individuales en las medidas de madurez, estaban asociados con disminuciones intra-individuales en el nivel auto-reportado de delitos. Los descubrimientos subrayaron el valor de las estrategias de intervención y tratamiento que mejoran la madurez

Risk of COVID-19 variant importation – How useful are travel control measures?

International audienceWe consider models for the importation of a new variant COVID-19 strain in a location already seeing propagation of a resident variant. By distinguishing contaminations generated by imported cases from those originating in the community, we are able to evaluate the contribution of importations to the dynamics of the disease in a community. We find that after an initial seeding, the role of importations becomes marginal compared to that of community-based propagation. We also evaluate the role of two travel control measures, quarantine and travel interruptions. We conclude that quarantine is an efficacious way of lowering importation rates, while travel interruptions have the potential to delay the consequences of importations but need to be applied within a very tight time window following the initial emergence of the variant