148,427 research outputs found

    Tilings with T and Skew Tetrominoes

    Get PDF
    We consider tiling problems in the integer lattice. Specifically, we look at a set of four T-tetrominoes and four skew tetrominoes and determine when this set can tile rectangles and modified rectangles. Local considerations and coloring arguments are the main methods used to prove the untileability of regions

    A Case for Undocumented Students in Higher Education: The Pursuit of Social Justice in Oregon Senate Bill 742

    Get PDF
    Should undocumented students be able to pay resident tuition rates at public universities? In the spring of 2011, the Oregon Senate introduced Senate Bill 742. The bill would allow undocumented students to pay resident tuition rates at the state\u27s seven public universities. This article presents philosophical arguments in support of the bill by using the ideologies outlined in egalitarian and communitarian ideas. Moreover, the liberal ideas of political philosophers Robert Nozick and Friedrich Hayek present counterarguments to my thesis. Senate Bill 742 could help to rectify the injustice inherent in the college admissions system

    Refracting the Male Gaze: Mary Cassatt’s Ocularcentric Message of Female Agency

    Get PDF
    Through analysis of ocularcentric (vision-privileged) messages in Mary Cassatt’s Reading Le Figaro (1878), I argue the portrait represents a strong early-career interest in countering gender hegemony that is largely unmatched in the artist’s later work. Reading the painting as a reaction to decreased autonomy following a consolidation of family living spaces, the present paper satisfies a dearth in Cassatt scholarship by addressing a yet-undiscussed motif of vision in Cassatt’s painting: the mirror. In a complete subversion of classic vanitas paintings, Cassatt alters the woman-and-mirror trope to emphasize her subject’s desire for an identity of female mind over female body. Defying European culture’s hyperspecularization (concentration on display value), which converted women into objects of male desire, Reading Le Figaro challenges preconceived schemas of gender and offers autonomy, self-definition, and active female sight as alternatives to the gaze-controlling subjugation of women

    Cupule aud acorn basic morpbological differences between Quercus ithaburensis Decne. subsp. ithaburensis and Quercus ithaburensis subsp. macrolepis (Kotschy) Hedge & Yalt

    Get PDF
    Estructura del glande y de la cúpula de Quercus ithaburensis Decne. subsp. ithaburensis y de Quercus ithaburensis subsp. inacrolepis (Kotschy) Hedge & Yalt.: Diferencias esenciales.Key words. Quercus ithaburensis, taxonomy, morphology, acorn, cupule, Israel, Turkey.Palabras clave. Quercus ithaburensis, taxonomía, morfología, glande, cúpula, Israel, Turquía

    The Effects of Owl Decoys and Non-threatening Objects on Bird Feeding Behavior

    Get PDF
    As traditional agricultural practices change, the scarecrow has also been renovated and modernized to include mock natural predators, such as owls, hawks, and falcons instead of comical human representations. These facsimiles represent an excellent opportunity to examine anti-predatory tactics and vigilance behavior in birds as a response to perceived threats. In this study, we tested songbird reaction to an owl decoy that mimicked the presence of a predator and to a non-threatening object placed in an oak woodland within Oregon’s Willamette Valley. Frequency of bird visitations to bird feeders when either a plastic owl or a cardboard box of similar size was used to examine the effect of the presence of a predator on bird feeding behavior. We hypothesized that introduction of a model owl would reduce the number of birds observed at a nearby feeder, but a cardboard box would not have a significant effect on bird presence. Using paired t-tests, we determined that a false predator was effective in deterring bird species from feeding, while a box was not

    Physical properties of four ring-porous hardwood species: Influence of wood rays on tangential and radial wood shrinkage

    Get PDF
    Some relationships between ray proportions, strength and shrinkage properties and basic density in hardwood species were highlighted. A better understanding of their relationships caused by the variation in moisture content in the hygroscopic domain could be a key factor in determining of wood stability properties and to determine the choice of a specific wood species according to its service life condition. The objectives of this study were (i) to determine the physical properties of various ring porous wood species (ii) and to evaluate the influence of wood rays (according to their proportions and volume) on physical properties of wood and more particularly on the Transverse Anisotropy Ratio for Shrinkage (TARS). This study focused on four ring-porous hardwood species; Castanea sativa, Quercus canariensis, Quercus petraea and Quercus robur, differing by the presence and abundance of their multiseriate wood rays. Basic densities, tangential shrinkages, radial shrinkages and the TARS of heartwood and sapwood from each wood species were determined. Wood-rays' proportions and volume were measured by the image analysis method, and their influence on the last three shrinkages was investigated. A significant correlation between wood ray proportions, wood shrinkage values and basic density was observed

    New State Distribution and Host Records of North American Buprestidae (Coleoptera)

    Get PDF
    The following new state records are reported for buprestid species in the eastern United States: Agrilus egeniformis Champlain and Knull and Polyceta elata LeConte from Georgia, Agrilus defectus LeConte and Agrilus vittaticollis (Randall) from Minnesota and Agrilus paramasculinus Champlain and Knull from Michigan and Indiana. Chrysobothris shawnee Wellso and Manley and Chrysobothris rugosiceps Melsheimer are reported from red oak (Quercus rubra L.) and English oak (Quercus robur L.) for the first time, after being reared from naturally infested host material collected in Michigan, USA

    Evidence from multivariate morphometric study of the quercus pubescens complex in southeast Italy

    Get PDF
    The name Quercus pubescens s.l. encompasses a complex of deciduous oak taxa with mainly southeastEuropean distribution and a large ecological niche. As the easternmost region of Italy, Apulia is rather isolated from a geographical and physiographical viewpoint and counts the highest number of oak species (10). In the taxonomic and phytosociological literature, the occurrence of several species belonging to the Quercus pubescens collective group is reported for this region. In order to verify if different sets of morphological characters are associated with different taxa, 24 populations of Quercus pubescens s.l. located in different ecological-geographical areas of Apulia were sampled. A total of 367 trees, 4254 leaves and 1120 fruits were collected and morphologically analysed. Overall, 25 morphological characters of oak leaves and fruits were statistically treated using both univariate and multivariate analysis. Nested ANOVA showed that leaves collected from a single tree exhibited a degree of morphological variability higher than that observed when comparing leaves coming from different trees of the same population and from different trees of different populations as well. Almost all the morphological characters analysed exhibited a continuous trend of variation so that none of them can be used as a character to discriminate between populations. Only leaf and fruit “size” and fruit petiole length emerged as slightly discriminating characters. Our results suggest that it is unlikely that more than one species belonging to the Quercus pubescens complex occurs in the Apulia region. Comparison between the Apulian populations and a genetically pure Q. pubescens population coming from a different area (the Molise region) strengthened the assumption as to the existence of a single species that can provisionally be classified under the name of Q. pubescens s.
    corecore