178 research outputs found

    Effects of stereotypical media representations of American Indians on implicit and explicit bias: the power of Pocahontas

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    According to cultivation theory, people learn information about the world from exposure to media and according to social cognitive theory, we learn how to interact with our social environment through observation of others. Together, these provide an explanation for why stereotypical media portrayals might increase biased attitudes. However, no research has examined the connection between media portrayals and biased attitudes for American Inidans, a group who are only represented in .2-.4% of American media (Fryberg, Markus, Oyserman, & Stone, 2008). The purpose of this study is to assess the role of stereotypical media portrayals of American Indians on both explicit and implicit attitudes and examine the potential mediating impact of both motivation to respond without prejudice and awareness of White privilege on these relationships. In this study participants were randomly assigned to watch either a series of videos with stereotypical representations of American Indians or a series of control videos. Measures of explicitly biased attitudes (modern racism and colorblind racial attitudes), implicitly biased attitudes, awareness of White privilege, and motivations to respond without prejudice (both internal and external) were assessed pre and post-test. Results from three separate hierarchical regression analyses suggest that media does impact modern racist attitudes towards American Indians, but not general colorblind racial attitudes nor implicit attitudes towards American Indians. Importantly, this relationship between media portrayals and modern racist attitudes is moderated by one’s awareness of White privilege such that higher awareness of White privilege only led to less endorsement of modern racist attitudes towards American Indians when not presented with stereotypical portrayals of American Indians. There were no differences between those low and high on awareness when stereotypical media portrayals were present. Implications and limitations are discussed

    C-MYC rearrangements are frequent in aggressive mature B-cell lymphoma with atypical morphology

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    Diagnosis and classification of aggressive mature B-cell lymphoma with atypical morphology remains a challenge. To identify factors that may contribute to the atypical morphology, we selected eight such cases and evaluated their morphologic, immunophenotypic and cytogenetic features and clinical outcomes. The neoplastic cells showed a diffuse monotonous infiltrating pattern with a spectrum of morphology including: 1) L1 lymphoblastic; 2) centroblastic; 3) immunoblastic; and 4) mixed centroblastic and immunoblastic. The lymphoma cells in most cases were positive for CD10 and/or BCL6, and showed BCL2 expression. 6 of 8 cases showed C-MYC rearrangements, and interestingly, all 6 cases demonstrated a proliferation index of ≤90%. 3 of the 6 cases also demonstrated t(14;18). Clinical follow-up indicated that aggressive mature B-cell lymphoma may benefit from more intensified chemotherapeutic regimens used for BL. Our study suggests that aggressive mature B-cell lymphoma with atypical morphology may be another “grey zone lymphoma” lying in the spectrum between Burkitt lymphoma and diffuse large B-cell lymphoma

    Pumping current of a Luttinger liquid with finite length

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    We study transport properties in a Tomonaga-Luttinger liquid in the presence of two time-dependent point like weak impurities, taking into account finite-length effects. By employing analytical methods and performing a perturbation theory, we compute the backscattering pumping current (I_bs) in different regimes which can be established in relation to the oscillatory frequency of the impurities and to the frequency related to the length and the renormalized velocity (by the electron-electron interactions) of the charge density modes. We investigate the role played by the spatial position of the impurity potentials. We also show how the previous infinite length results for I_bs are modified by the finite size of the system.Comment: 9 pages, 7 figure

    Controls of primary production in two phytoplankton blooms in the Antarctic Circumpolar Current

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    The Antarctic Circumpolar Current has a high potential for primary production and carbon sequestration through the biological pump. In the current study, two large-scale blooms observed in 2012 during a cruise with R.V. Polarstern were investigated with respect to phytoplankton standing stocks, primary productivity and nutrient budgets. While net primary productivity was similar in both blooms, chlorophyll a –specific photosynthesis was more efficient in the bloom closer to the island of South Georgia (39 °W, 50 °S) compared to the open ocean bloom further east (12 °W, 51 °S). We did not find evidence for light being the driver of bloom dynamics as chlorophyll standing stocks up to 165 mg m-2 developed despite mixed layers as deep as 90 m. Since the two bloom regions differ in their distance to shelf areas, potential sources of iron vary. Nutrient (nitrate, phosphate, silicate) deficits were similar in both areas despite different bloom ages, but their ratios indicated more pronounced iron limitation at 12 °W compared to 39 °W. While primarily the supply of iron and not the availability of light seemed to control onset and duration of the blooms, higher grazing pressure could have exerted a stronger control toward the declining phase of the blooms

    High resolution water column phytoplankton composition across the Atlantic Ocean from ship-towed vertical undulating radiometry.

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    Different phytoplankton groups dominate ocean biomes and they drive differently the marine food web and the biogeochemical cycles. However, their distribution over most parts of the global ocean remains uncertain due to limitations in the sampling resolution of currently available in situ and satellite data. Information below surface waters are especially limited because satellite sensors only provide information on the first optical depth. We present measurements obtained during Polarstern cruise PS113 (May–June 2018) across the Atlantic Ocean from South America to Europe along numerous transects. We measured the hyperspectral underwater radiation field continuously over several hours from a vertical undulating platform towed behind the ship. Equivalent measurements were also taken at specific stations. The concentrations of phytoplankton pigments were determined on discrete water samples. Via diagnostic pigment analysis we derived the phytoplankton group chlorophyll a concentration (Chla) from this pigment data set. We obtained high resolution phytoplankton group Chla data from depth resolved apparent optical properties derived from the underwater radiation data by applying an empirical orthogonal function (EOF) analysis to the spectral data set and subsequently developing regression models using the pigment based phytoplankton group Chla and selected EOF modes. To our knowledge, this is the first data set with high horizontal coverage (50–150 km) and resolution (∼1 km) that is also resolved vertically for the Chla of major taxonomic phytoplankton groups. Subsampling with 500 permutations for cross validation verified the high robustness of our estimates to enable predictions of seven different phytoplankton groups’ Chla and of total Chla (R2 and median percent differences of the cross validation are within 0.45–0.68 and 29–53%, respectively). Our depth resolved phytoplankton groups’ Chla data reflect well the different biogeochemical provinces within the Atlantic Ocean transect and follow the distributions encountered by previous point observations. This verifies the high quality of our retrievals and provides the prospect to put similar radiometers on profiling floats or gliders which would enable the large-scale collection of vertically resolved phytoplankton data at much improved horizontal coverage relative to discrete sampling
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