95 research outputs found
Family-Centered, Home-Based Services: Impact of Client Characteristics on Program Outcomes
The University Archives has determined that this item is of continuing value to OSU's history.Scannapieco, Maria, Ph.D., University of Minnesota, Minneapolis, MN, University of Maryland, Baltimore, MD - "Family-Centered, Home-Based Services: Impact of Client Characteristics on Program Outcomes".The Ohio State University College of Social Wor
Clues for the origin of the fundamental metallicity relations. I: The hierarchical building up of the structure
We analyse the evolutionary history of galaxies formed in a hierarchical
scenario consistent with the concordance -CDM model focusing on the
study of the relation between their chemical and dynamical properties. Our
simulations consistently describe the formation of the structure and its
chemical enrichment within a cosmological context. Our results indicate that
the luminosity-metallicity (LZR) and the stellar mass-metallicity (MZR)
relations are naturally generated in a hierarchical scenario. Both relations
are found to evolve with redshift. In the case of the MZR, the estimated
evolution is weaker than that deduced from observational works by approximately
0.10 dex. We also determine a characteristic stellar mass, , which segregates the simulated galaxy population
into two distinctive groups and which remains unchanged since , with a
very weak evolution of its metallicity content. The value and role played by
is consistent with the characteristic mass estimated from the SDSS galaxy
survey by Kauffmann et al. (2004). Our findings suggest that systems with
stellar masses smaller than are responsible for the evolution of this
relation at least from . Larger systems are stellar dominated and
have formed more than 50 per cent of their stars at , showing very
weak evolution since this epoch. We also found bimodal metallicity and age
distributions from , which reflects the existence of two different
galaxy populations. Although SN feedback may affect the properties of galaxies
and help to shape the MZR, it is unlikely that it will significantly modify
since, from this stellar mass is found in systems with circular
velocities larger than 100 \kms.Comment: 17 pages, 13 figures. Minor changes to match accepted version.
Accepted October 3 MNRA
Fingerprints of the Hierarchical Building up of the Structure on the Mass-Metallicity Relation
We study the mass-metallicity relation of galactic systems with stellar
masses larger than 10^9 Mo in Lambda-CDM scenarios by using chemical
hydrodynamical simulations. We find that this relation arises naturally as a
consequence of the formation of the structure in a hierarchical scenario. The
hierarchical building up of the structure determines a characteristic stellar
mass at M_c ~10^10.2 Moh^-1 which exhibits approximately solar metallicities
from z ~ 3 to z=0. This characteristic mass separates galactic systems in two
groups with massive ones forming most of their stars and metals at high
redshift. We find evolution in the zero point and slope of the mass-metallicity
relation driven mainly by the low mass systems which exhibit the larger
variations in the chemical properties. Although stellar mass and circular
velocity are directly related, the correlation between circular velocity and
metallicity shows a larger evolution with redshift making this relation more
appropriate to confront models and observations. The dispersion found in both
relations is a function of the stellar mass and reflects the different
dynamical history of evolution of the systems.Comment: 4 pages, 4 figures. Accepted MNRAS Letter
Grandma\u27s Babies: The Problem of Welfare Eligibility for Children Raised by Relatives
This article provides a brief history of children raised by relatives and examines the welfare eligibility of these families, emphasizing changes under the Personal Responsibility & Work Opportunity Act of 1996 (PR&WOA). The revolution in public welfare places many care-giving relatives atfinancial risk. Depending on their states\u27 plans for implementing the PR& WOA, children and their relative caregivers may lose state support. The article presents the social welfare policy responses of a number of states to the problems of kinship care-giving, formal kinship foster care, the PR&WOA, and other social welfare provisions. Unintended consequences of welfare reform are highlighted
Dynamics of genetic variability in Anastrepha fraterculus (Diptera: Tephritidae) during adaptation to laboratory rearing conditions
BACKGROUND: Anastrepha fraterculus is one of the most important fruit fly plagues in the American continent and only chemical control is applied in the field to diminish its population densities. A better understanding of the genetic variability during the introduction and adaptation of wild A. fraterculus populations to laboratory conditions is required for the development of stable and vigorous experimental colonies and mass-reared strains in support of successful Sterile Insect Technique (SIT) efforts.
METHODS: The present study aims to analyze the dynamics of changes in genetic variability during the first six generations under artificial rearing conditions in two populations: a) a wild population recently introduced to laboratory culture, named TW and, b) a long-established control line, named CL.
RESULTS: Results showed a declining tendency of genetic variability in TW. In CL, the relatively high values of genetic variability appear to be maintained across generations and could denote an intrinsic capacity to avoid the loss of genetic diversity in time.
DISCUSSION: The impact of evolutionary forces on this species during the adaptation process as well as the best approach to choose strategies to introduce experimental and mass-reared A. fraterculus strains for SIT programs are discussed.Fil: Scannapieco, Alejandra Carla. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Remis, Maria Isabel. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de EcologÃa, Genética y Evolución. Laboratorio de Genética de la Estructura Poblacional; ArgentinaFil: Juri, Marianela Lucia. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Vera, MarÃa Teresa. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de AgronomÃa y Zootecnia. Cátedra Terapéutica Vegetal; ArgentinaFil: Segura, Diego Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Cladera, Jorge Luis. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Lanzavecchia, Silvia Beatriz. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentin
Clues for the origin of the fundamental metallicity relations - I. The hierarchical building up of the structure
We analyse the evolutionary history of galaxies formed in a hierarchical scenario consistent with the concordance Lambda cold dark matter (CDM) model focusing on the study of the relation between their chemical and dynamical properties. Our simulations consistently describe the formation of the structure and its chemical enrichment within a cosmological context. Our results indicate that the luminosity–metallicity and the stellar mass–metallicity (LZR and MZR) relations are naturally generated in a hierarchical scenario. Both relations are found to evolve with redshift. In the case of the MZR, the estimated evolution is weaker than that deduced from observational works by approximately 0.10 dex. We also determine
a characteristic stellar mass, Mc ≈ 3 × 1010 M⊙, which segregates the simulated galaxy population into two distinctive groups and which remains unchanged since z ∼ 3, with a very weak evolution of its metallicity content. The value and role played by Mc is consistent with the characteristic mass estimated from the SDSS galaxy survey by Kauffmann et al. Our findings suggest that systems with stellar masses smaller than Mc are responsible for the evolution of this relation at least from z ≈ 3. Larger systems are stellar dominated and have formed more than 50 per cent of their stars at z 2, showing very weak evolution since this epoch. We also found bimodal metallicity and age distributions from z ∼ 3, which reflects the existence of two different galaxy populations. Although SN feedback may affect the properties of galaxies and help to shape the MZR, it is unlikely that it will significantly modify Mc since, from z = 3 this stellar mass is found in systems with circular velocities larger than 100 km s −1Fil: de Rossi, Maria Emilia. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Tissera, Patricia Beatriz. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Scannapieco, Cecilia. Gobierno de la Republica Federal de Alemania. Max Planck Institut Fur Astrophysik; Alemania. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; Argentin
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