Getting Ahead or Losing Ground: Economic Mobility in America

Combines earlier research to present a comprehensive analysis of relative mobility, absolute mobility, and changes in income inequality. Focuses on intergenerational mobility, immigrants, comparisons by gender and race, and the role of education

The entropy of elliptical galaxies in Coma: a clue for a distance indicator

We have fitted the surface brightness of a sample of 79 elliptical galaxies pertaining to the Coma cluster of galaxies using the Sersic profile. This model is defined through three primary parameters: scale length (a), intensity (\Sigma_0), and a shape parameter (\nu); physical and astrophysical quantities may be computed from these parameters. We show that correlations are stronger among primary parameters than the classical astrophysical ones. In particular, the galaxies follow a high correlation in \nu and a parameters. We show that the \nu and a correlation satisfies a constant specific entropy condition. We propose to use this entropy relation as distance indicator for clusters.Comment: 5 pages, 3 figures, submitted to MNRAS Letter

Surficial sediment texture database for the south-western Iberian Atlantic margin

Assessing the impact of changes on the environment driven by natural or anthropogenic forcers includes the comparison between antecedent and post-event conditions. The latter is particularly relevant in order to better understand to which extent those changes actually impact or alter a particular environment and associated services and to determine the resilience of a system. In this regard, it becomes essential to create or provide databases to inform about baseline conditions. Here, we present a database that integrates surficial sediment samples collected and analysed for textural characterization within the framework of a series of research projects over circa 20 years. Collected samples along the south-western Atlantic margin of the Iberian Peninsula extend from estuaries and beaches to the adjacent continental shelf. For the case of the more dynamic environments, namely coastal sandy barriers, samples were repeated over time in order to capture the intrinsic variability of the system. Examples of the utility of this data set for a variety of purposes and environments are also included within this paper through three examples. Therefore, here we show the added value of the database as it can be used to assess the impact of a particular event or activity at an estuary by providing baseline conditions, evaluate the continental shelf sediment suitability for nourishment activities, or contribute to the understanding of the morphodynamics and classification of beaches. Finally, it is worth stating the importance of such databases to analyse medium- to long-term variability as the one induced by sea level rise, changes in storminess, or human activities.FCT Investigator programme [IF/01047/2014]info:eu-repo/semantics/publishedVersio

Comportamento experimental de diferentes tipos de conectores metálicos

A realização de estruturas mistas de aço e betão requer o funcionamento conjunto destes dois materiais. A ligação entre eles é conseguida com a utilização de conectores metálicos. Neste âmbito, tem sido realizada uma considerável quantidade de estudos que abordam o comportamento de diversos tipos de conectores metálicos. O desejo de obter um comportamento óptimo com custos mínimos motivou o desenvolvimento de várias soluções. Neste artigo, procura-se descrever o comportamento de diferentes tipos de conectores observado em ensaios experimentais realizados na Universidade do Minho (UM) ou em estreita colaboração da UM com outras entidades. Apresentam-se as vantagens e as desvantagens associadas a cada tipologia de conexão analisada. Para além dos usuais conectores tipo perno, discutem-se os resultados obtidos com conectores do tipo T, tipo Perfobond, tipo Crestbond e ligação por aderência

Snapshot of macroalgae and fish assemblages in temperate reefs in the Southern European Atlantic Ecoregion

Most of the biodiversity studies in the South European Atlantic Shelf ecoregion are limited to shallow subtidal or intertidal habitats, while deeper reef habitats, also of relevant ecological importance, are particularly understudied. Macroalgal communities, associated fauna, and sea surface temperature were studied in deep reefs (25-30 m) at two locations in this ecoregion: Parcel, North of Portugal (41 degrees N), and Tarifa, Southern Spain (35 degrees N). Specifically, algal assemblages were assessed using biomass collection and associated ichthyofauna was assessed using visual census techniques using scuba. Seawater surface temperature was higher (>3 degrees C) in the southern region-Tarifa, compared to the northern region-Parcel. Our survey revealed 18 fish species and 23 algae species. The highest abundance of cold-water species (both macroalgae and fish species) was recorded in Parcel and warm-water species were dominant in Tarifa. In light of climate global trends, both regions might experience biodiversity shifts towards tropicalization. Current knowledge on their biodiversity is imperative to further evaluate potential shifts.info:eu-repo/semantics/publishedVersio