136 research outputs found

    Whiteness and the Return of the Black Body

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    The objective of this dissertation project is to theorize and understand Black embodiment within the context of white hegemony, that is, within the context of a white racist anti-Black world. I theorize the Black body as a site of lived historicity vis-á-vis whiteness as the transcendental signified or as that which takes itself to be unconditioned. I theorize how the Black body, under the power of the white gaze, which is linked to cultural, symbolic, and material power, undergoes what I refer to as a phenomenological return. Examples were taken from the work of Ralph Ellsion, Frederick Douglass, W.E.B Du Bois, Frantz Fanon, and others. It is here that the presumption of the plasticity of the Black body, and the fact that it is a site of contested meanings, speaks to the historicity of the Black body\u27s being as lived and meant within the interstices of social semiotics. I interrogated the Black body as a fixed and material truth that is said to pre-exist its relations with a white normative world of anti-Blackness. On this score, I maintain that not only does the Black body defy the ontic fixity projected upon it through the white gaze, and, hence, through the episteme of whiteness, but the white body is also fundamentally symbolic, requiring demystification of its status as norm, the paragon of beauty, order, innocence, purity, restraint, and nobility. The insights of various critical whiteness studies theorists were indispensable. I explore this larger racial Manichaean divide through the use of blending autobiography, history, and philosophical fiction. Through the Middle Passage and enslavement, Black bodies became the site not only of white racist discursive constructions, but the victim of white brutality and inhumanity that literally left the Black body marked, scarred. Through an exploration of Black resistance to the distorted Black imago of the white imaginary, I theorize ways in which the Black body challenged its conceptualization as docile. White hegemony also interpellated the white body as that which is epistemologically and ontologically given. In this way, it was necessary to render the unseen of whiteness seen at the site of the quotidian, and explore ways in which whites can disrupt whitely ways of being-in-the-world

    Spitzer's Contribution to the AGN Population

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    (abridged) Infrared selection is a potentially powerful way to identify heavily obscured AGN missed in even the deepest X-ray surveys. Using a 24 micron-selected sample in GOODS-S, we test the reliability and completeness of three infrared AGN selection methods: (1) IRAC color-color selection, (2) IRAC power-law selection, and (3) IR-excess selection; we also evaluate a number of infrared excess approaches. We find that the vast majority of non-power-law IRAC color-selected AGN candidates in GOODS-S have colors consistent with those of star-forming galaxies. Contamination by star-forming galaxies is most prevalent at low 24 micron flux densities (~100 uJy) and high redshifts (z~2), but the fraction of potential contaminants is still high (~50%) at 500 uJy, the highest flux density probed reliably by our survey. AGN candidates selected via a simple, physically-motivated power-law criterion (PLGs), however, appear to be reliable. We confirm that the infrared excess methods successfully identify a number of AGN, but we also find that such samples may be significantly contaminated by star-forming galaxies. Adding only the secure Spitzer-selected PLG, color-selected, IR-excess, and radio/IR-selected AGN candidates to the deepest X-ray-selected AGN samples directly increases the number of known X-ray AGN (84) by 54-77%, and implies an increase to the number of 24 micron-detected AGN of 71-94%. Finally, we show that the fraction of MIR sources dominated by an AGN decreases with decreasing MIR flux density, but only down to f_24 = 300 uJy. Below this limit, the AGN fraction levels out, indicating that a non-negligible fraction (~10%) of faint 24 micron sources (the majority of which are missed in the X-ray) are powered not by star formation, but by the central engine.Comment: Accepted for publication in The Astrophysical Journal, 26 pages, 14 figures, 6 table

    Metastatic progression and gene expression between breast cancer cell lines from African American and Caucasian women

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    African American (AA) women have a lower overall incidence of breast cancer than do Caucasian (CAU) women, but a higher overall mortality. Little is known as to why the incidence of breast cancer is lower yet mortality is higher in AA women. Many studies speculate that this is only a socio-economical problem. This investigation suggests the possibility that molecular mechanisms contribute to the increased mortality of AA women with breast cancer. This study investigates the expression of 14 genes which have been shown to play a role in cancer metastasis. Cell lines derived from AA and CAU patients were analyzed to demonstrate alterations in the transcription of genes known to be involved in cancer and the metastatic process. Total RNA was isolated from cell lines and analyzed by RT-PCR analysis. Differential expression of the 14 targeted genes between a spectrum model (6 breast cancer cell lines and 2 non-cancer breast cell lines) and a metastasis model (12 metastatic breast cancer cell lines) were demonstrated. Additionally, an in vitro comparison of the expression established differences in 5 of the 14 biomarker genes between African American and Caucasian breast cell lines. Results from this study indicates that altered expression of the genes Atp1b1, CARD 10, KLF4, Spint2, and Acly may play a role in the aggressive phenotype seen in breast cancer in African American women

    Cardiovascular Health in African Americans: A Scientific Statement From the American Heart Association

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    BACKGROUND AND PURPOSE: Population-wide reductions in cardiovascular disease incidence and mortality have not been shared equally by African Americans. The burden of cardiovascular disease in the African American community remains high and is a primary cause of disparities in life expectancy between African Americans and whites. The objectives of the present scientific statement are to describe cardiovascular health in African Americans and to highlight unique considerations for disease prevention and management. METHOD: The primary sources of information were identified with PubMed/Medline and online sources from the Centers for Disease Control and Prevention. RESULTS: The higher prevalence of traditional cardiovascular risk factors (eg, hypertension, diabetes mellitus, obesity, and atherosclerotic cardiovascular risk) underlies the relatively earlier age of onset of cardiovascular diseases among African Americans. Hypertension in particular is highly prevalent among African Americans and contributes directly to the notable disparities in stroke, heart failure, and peripheral artery disease among African Americans. Despite the availability of effective pharmacotherapies and indications for some tailored pharmacotherapies for African Americans (eg, heart failure medications), disease management is less effective among African Americans, yielding higher mortality. Explanations for these persistent disparities in cardiovascular disease are multifactorial and span from the individual level to the social environment. CONCLUSIONS: The strategies needed to promote equity in the cardiovascular health of African Americans require input from a broad set of stakeholders, including clinicians and researchers from across multiple disciplines

    Development of a Multiplex Real-Time PCR Assay for the detection of ruminant DNA

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    The U.S. Food and Drug Administration (FDA) has previously validated a real-time PCR-based assay that is currently being used by the FDA and several state laboratories as the official screening method. Due to several shortcomings to the assay, a multiplex real-time PCR assay (MRTA) to detect three ruminant species (bovine, caprine, and ovine) was developed using a lyophilized bead design. The assay contained two primer or probe sets: a "ruminant" set to detect bovine-, caprine-, and ovine-derived materials and a second set to serve as an internal PCR control, formatted using a lyophilized bead design. Performance of the assay was evaluated against stringent acceptance criteria developed by the FDA's Center for Veterinary Medicine's Office of Research. The MRTA for the detection of ruminant DNA passed the stringent acceptance criteria for specificity, sensitivity, and selectivity. The assay met sensitivity and reproducibility requirements by detecting 30 of 30 complete feed samples fortified with meals at 0.1 % (wt/wt) rendered material from each of the three ruminant species. The MRTA demonstrated 100 % selectivity (0.0 % false positives) for negative controls throughout the assessment period. The assay showed ruggedness in both sample selection and reagent preparation. Second and third analyst trials confirmed the quality of the written standard operating procedure with consistency of results. An external laboratory participating in a peer-verification trial demonstrated 100 % specificity in identifying bovine meat and bone meal, while exhibiting a 0.03 % rate of false positives. The assay demonstrated equal levels of sensitivity and reproducibility compared with the FDA's current validated real-time PCR assay. The assay detected three prohibited species in less than 1.5 h of total assay time, a significant improvement over the current real-time assay. These results demonstrated this assay's suitability for routine regulatory use both as a primary screening tool and as a confirmatory test

    Spitzer and HHT observations of starless cores: masses and environments

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    We present Spitzer observations of a sample of 12 starless cores selected to have prominent 24 micron shadows. The Spitzer images show 8 and 24 micron shadows and in some cases 70 micron shadows; these spatially resolved absorption features trace the densest regions of the cores. We have carried out a 12CO (2-1) and 13CO (2-1) mapping survey of these cores with the Heinrich Hertz Telescope (HHT). We use the shadow features to derive optical depth maps. We derive molecular masses for the cores and the surrounding environment; we find that the 24 micron shadow masses are always greater than or equal to the molecular masses derived in the same region, a discrepancy likely caused by CO freeze--out onto dust grains. We combine this sample with two additional cores that we studied previously to bring the total sample to 14 cores. Using a simple Jeans mass criterion we find that ~ 2/3 of the cores selected to have prominent 24 micron shadows are collapsing or near collapse, a result that is supported by millimeter line observations. Of this subset at least half have indications of 70 micron shadows. All cores observed to produce absorption features at 70 micron are close to collapse. We conclude that 24 micron shadows, and even more so the 70 micron ones, are useful markers of cloud cores that are approaching collapse.Comment: 41 pages, 28 figures, 5 tables; accepted by Ap

    Spitzer observations of a 24 micron shadow: Bok Globule CB190

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    We present Spitzer observations of the dark globule CB190 (L771). We observe a roughly circular 24 micron shadow with a 70 arcsec radius. The extinction profile of this shadow matches the profile derived from 2MASS photometry at the outer edges of the globule and reaches a maximum of ~32 visual magnitudes at the center. The corresponding mass of CB190 is ~10 Msun. Our 12CO and 13CO J = 2-1 data over a 10 arcmin X 10 arcmin region centered on the shadow show a temperature ~10 K. The thermal continuum indicates a similar temperature for the dust. The molecular data also show evidence of freezeout onto dust grains. We estimate a distance to CB190 of 400 pc using the spectroscopic parallax of a star associated with the globule. Bonnor-Ebert fits to the density profile, in conjunction with this distance, yield xi_max = 7.2, indicating that CB190 may be unstable. The high temperature (56 K) of the best fit Bonnor-Ebert model is in contradiction with the CO and thermal continuum data, leading to the conclusion that the thermal pressure is not enough to prevent free-fall collapse. We also find that the turbulence in the cloud is inadequate to support it. However, the cloud may be supported by the magnetic field, if this field is at the average level for dark globules. Since the magnetic field will eventually leak out through ambipolar diffusion, it is likely that CB190 is collapsing or in a late pre-collapse stage.Comment: 16 pages, 13 figures, accepted for publication in Ap

    Spitzer Observations of L429: A Near-collapse or Collapsing Starless Core

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    We present Spitzer infrared observations of the starless core L429. The IR images of this core show an absorption feature, caused by the dense core material, at wavelengths <= 70 micron. The core has a steep density profile, and reaches A_V > 35 mag near the center. We show that L429 is either collapsing or in a near-collapse state.Comment: 5 pages, 3 figures, emulateapj format, accepted for publication in ApJ

    Prognosis of heart failure recorded in primary care, acute hospital admissions, or both: a population-based linked electronic health record cohort study in 2.1 million people

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    Aims: The prognosis of patients hospitalized for worsening heart failure (HF) is well described but not that of patients managed solely in non-acute settings such as primary care or secondary outpatient care. We assessed the distribution and prognostic differences for patients with HF either recorded in primary care (including secondary out-patient care) (PC), hospital admissions alone, or known in both contexts. Methods and Results: This study was part of the CALIBER programme, comprising linked data from primary care, hospital admissions, and death-certificates for 2.1 million inhabitants of England. We identified 89,554 patients with incident HF, of whom 23,547(26%) were recorded in PC but never hospitalised, 30,629(34%) in hospital admissions but not known in PC, 23,681(26%) in both, and 11,697(13%) in death-certificates only. Highest prescription rates of ACEi, betablockers, and minerocorticoid receptor antagonists was found in patients known in both contexts. The respective 5-year survival in the first three groups was 43.9% (95%CI 43.2-44.6%), 21.7% (95%CI 21.1-22.2%), and 39.8% (95%CI 39.2-40.5%), compared to 88.1% (95%CI 87.9-88.3%) in the age and sex matched general population. Conclusion: In the general population, one in four patients with HF will not be hospitalised for worsening HF within a median follow up of 1.7 years, yet they still have a poor five-year prognosis. Patients admitted to hospital with worsening HF but not known with HF in primary care have the worst prognosis and management. Mitigating the prognostic burden of HF requires greater consistency across primary- and secondary care in the identification, profiling and treatment of patients

    Spitzer Observations of Bok Globule B335: Isolated Star Formation Efficiency and Cloud Structure

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    We present infrared and millimeter observations of Barnard 335, the prototypical isolated Bok globule with an embedded protostar. Using Spitzer data we measure the source luminosity accurately; we also constrain the density profile of the innermost globule material near the protostar using the observation of an 8.0 um shadow. HHT observations of 12CO 2 --> 1 confirm the detection of a flattened molecular core with diameter ~10000 AU and the same orientation as the circumstellar disk (~100 to 200 AU in diameter). This structure is probably the same as that generating the 8.0 um shadow and is expected from theoretical simulations of collapsing embedded protostars. We estimate the mass of the protostar to be only ~5% of the mass of the parent globule.Comment: 15 pages, 17 figures, emulateapj format, accepted for publication in Ap
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