2,807 research outputs found

    Increased Incidence of Loco-Regional Recurrences Among African American Women with Terminal Stage Breast Cancer

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    A prospective analysis of women with terminal breast cancer admitted to CHNE from November 2006–August 2007 evaluated anecdotal observations that African American (AA) women are likelier than Caucasian women to evidence loco-regional recurrences (LRR). Women with terminal breast cancer who were admitted to CHNE, a not-for-profit hospice serving over 90% of Northeast Florida hospice patients, were eligible for participation. 134 terminal breast cancer patients were assessed by hospice nurses for LRR presence via chest wall examination. 80% of them (107) were Caucasian, 17% (23) were AA and 3% (4) were of other ethnicities. Evidence of LRR were noted in 13% of the women (17/134). The proportion of patients with LRR was higher in AA women than Caucasian women (26% vs. 10%, 6/23 vs. 11/107, respectively), although this difference was not statistically significant (p = 0.08). The majority of Caucasian women with LRR consented to a medical record review, but a minority of AA women consented (8/11 vs. 2/6, respectively, p = 0.16)

    Flux Compactifications of M-Theory on Twisted Tori

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    We find the bosonic sector of the gauged supergravities that are obtained from 11-dimensional supergravity by Scherk-Schwarz dimensional reduction with flux to any dimension D. We show that, if certain obstructions are absent, the Scherk-Schwarz ansatz for a finite set of D-dimensional fields can be extended to a full compactification of M-theory, including an infinite tower of Kaluza-Klein fields. The internal space is obtained from a group manifold (which may be non-compact) by a discrete identification. We discuss the symmetry algebra and the symmetry breaking patterns and illustrate these with particular examples. We discuss the action of U-duality on these theories in terms of symmetries of the D-dimensional supergravity, and argue that in general it will take geometric flux compactifications to M-theory on non-geometric backgrounds, such as U-folds with U-duality transition functions.Comment: Latex, 47 page

    Ontogenetic variation in the crocodylian vestibular system

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    Crocodylians today live in tropical to subtropical environments, occupying mostly shallow waters. Their body size changes drastically during ontogeny, as do their skull dimensions and bite forces, which are associated with changes in prey preferences. Endocranial neurosensory structures have also shown to change ontogenetically, but less is known about the vestibular system of the inner ear. Here we use 30 high-resolution computed tomography (CT) scans and three-dimensional geometric morphometrics to investigate the size and shape changes of crocodylian endosseous labyrinths throughout ontogeny, across four stages (hatchling, juvenile, subadult and adult). We find two major patterns of ontogenetic change. First, the labyrinth increases in size during ontogeny, with negative allometry in relation to skull size. Second, labyrinth shape changes significantly, with hatchlings having shorter semicircular canal radii, with thicker diameters and an overall dorsoventrally shorter labyrinth than those of more mature individuals. We argue that the modification of the labyrinth during crocodylian ontogeny is related to constraints imposed by skull growth, due to fundamental changes in the crocodylian braincase during ontogeny (e.g. verticalisation of the basicranium), rather than changes in locomotion, diet, or other biological functions or behaviours

    Generalised Geometry for M-Theory

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    Generalised geometry studies structures on a d-dimensional manifold with a metric and 2-form gauge field on which there is a natural action of the group SO(d,d). This is generalised to d-dimensional manifolds with a metric and 3-form gauge field on which there is a natural action of the group EdE_{d}. This provides a framework for the discussion of M-theory solutions with flux. A different generalisation is to d-dimensional manifolds with a metric, 2-form gauge field and a set of p-forms for pp either odd or even on which there is a natural action of the group Ed+1E_{d+1}. This is useful for type IIA or IIB string solutions with flux. Further generalisations give extended tangent bundles and extended spin bundles relevant for non-geometric backgrounds. Special structures that arise for supersymmetric backgrounds are discussed.Comment: 31 page

    Accuracy of the diagnosis of hypertensive nephrosclerosis in African Americans: A report from the African American Study of Kidney Disease (AASK) Trial

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    Accuracy of the diagnosis of hypertensive nephrosclerosis in African Americans: A report from the African American Study of Kidney Disease (AASK) Trial. African Americans have excess hypertension and end-stage renal disease presumed due to hypertension compared to Caucasians. The AASK was designed to examine the impact of antihypertensive therapies and two levels of blood pressure control on the rate of decline of GFR in African Americans with presumed hypertensive renal disease. During the pilot phase of the trial, eligible participants were requested to undergo renal biopsy to assess the underlying lesions in this population. Eighty-eight hypertensive (diastolic BP > 95mm Hg) non-diabetic African American patients between the ages of 18 to 70 years, with GFR between 25 to 70 ml/min/1.73m2 and without marked proteinuria were assessed for possible renal biopsy. Forty-three patients did not undergo renal biopsy due to refusal or contraindications. Adequate renal biopsies were obtained in 39 of the remaining 46 patients. Biopsy findings were analyzed and then compared to clinical parameters. The 39 patients studied, 29 men and 10 women, were on average 53.0 ± 11.0 years old, and had a MAP of 109 ± 15mm Hg and GFR 51.7 ± 13.6ml/min/1.73m2 (not significantly different from nonbiopsied patients). Thirty-eight of these 39 biopsies showed arteriosclerosis and/or arteriolosclerosis, severity on average 1.5 ± 0.9 and 1.5 ± 0.8, respectively on a 0 to 3+ scale. Interstitial fibrosis was moderate, 1.3 ± 0.9 (0 to 3+ scale). Segmental glomerulosclerosis was present in five biopsies, and in one patient, biopsy and clinical findings were consistent with idiopathic focal segmental glomerulosclerosis. Additional lesions included mesangiopathic glomerulonephritis in one patient, basement membrane thickening suggestive of diabetic nephropathy in one, and cholesterol emboli in two cases. Arteriolar and arterial sclerosis were tightly linked, and correlated with interstitial fibrosis and the reciprocal of serum creatinine. Global glomerulosclerosis was extensive, involving on average 43 ± 26% of glomeruli. The extent of this lesion did not correlate with degree of arteriolar or arterial thickening, but did correlate with systolic blood pressure (P = 0.0174), the reciprocal of serum creatinine (P = 0.0009), serum cholesterol (P = 0.0129) and interstitial fibrosis (P < 0.0001). These data underscore that renal biopsies in non-diabetic hypertensive African-Americans with mild to moderate renal insufficiency in the absence of marked proteinuria are overwhelmingly likely to show renal vascular lesions consistent with the clinical diagnosis of hypertensive nephrosclerosis

    Copper(II) and Nickel(II) Octabromo-tetrakis(pentafluorophenyl)Porphyrin Complexes

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    The copper and nickel complexes of 2,3,7,8,12,13,17, 18-octabromo-5,10,15,20-tetrakis(pentaftuorophenyl) porphyrin ({4,5,9,10,14,15,19,20-octabromo-2,7,12,17-tetrakis(pentaftuorophenyl)-21,22,23,24-tetraazapentacyclo[l6.2.1.1^(3,6).l^(8,11).l^(13,16)]tetracosa-l,3-(22),4,6,8(23),9,11,13(24),14,16,18(21),19-dodecaene }copper(II) 0.5-dichloromethane solvate and {4,5,9,10,14,15,19,20-octabromo-2,7,12,17-tetrakis(pentaftuorophenyl)-21,22,23,24-tetraazapentacyclo( 16.2.1.1^(3,6).l^(8,11).l^(13,16)]tetracosa-l,3(22),4,6,8(23),9,ll,13(24),14,16,18(21),19-dodecaene} nickel(II)0.5-dichloromethane solvate) form isostructural crystals. There is significant distortion from planarity of the porphyrin ring caused by the octabromo substituents interacting with the meso-pentafluorophenyl groups and with each other, with departures of the Br atoms from the plane defined by the four N atoms of up to 2.36 A. This tetrahedral distortion of the molecule does not result in any significant changes in bond distances from those in non-halogenated tetraphenylporphyrin complexes

    A 610-MHz survey of the ELAIS-N1 field with the Giant Metrewave Radio Telescope - Observations, data analysis and source catalogue

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    Observations of the ELAIS-N1 field taken at 610 MHz with the Giant Metrewave Radio Telescope are presented. Nineteen pointings were observed, covering a total area of 9 square degrees with a resolution of 6" x 5", PA +45 deg. Four of the pointings were deep observations with an rms of 40 microJy before primary beam correction, with the remaining fifteen pointings having an rms of 70 microJy. The techniques used for data reduction and production of a mosaicked image of the region are described, and the final mosaic is presented, along with a catalogue of 2500 sources detected above 6 sigma. This work complements the large amount of optical and infrared data already available on the region. We calculate 610-MHz source counts down to 270 microJy, and find further evidence for the turnover in differential number counts below 1 mJy, previously seen at both 610 MHz and 1.4 GHz.Comment: 12 pages, 18 figures, two tables. Table 1 can be found in full via http://www.mrao.cam.ac.uk/surveys/ . Accepted for publication in MNRA
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