281 research outputs found

    High resolution observations of Jovian magnetospheric microwave synchrotron emission

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    High resolution radio observations of Jupiter were investigated with the use of the Stanford synthesis telescope. The best fit disk was computed from the emission of Jupiter and the residual brightness, due to nonthermal mechanisms was measured

    Rhetorics of Cancer in America

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    This dissertation examines the constitutive functions of multimodal cancer rhetoric in America and critiques the resulting ideological consequences. This study locates the multimodal manifestations of American cancer rhetoric within three realms – textual/oral, visual/material, and bodily/performative. Beginning in the discursive realm, it traces the metaphoric evolution of the “War on Cancer” and the “Cancer Moonshot Initiative” in presidential rhetoric before then moving to an analysis of artifacts from American cancer rhetoric’s nondiscursive formations. For the visual/material modality, this study analyzes the pink breast cancer “awareness” ribbon and the yellow Livestrong cancer “support” bracelet; for the bodily/performative modality, it then considers two portrayals of cancered bodies in popular media – Walter White from the television series Breaking Bad and the featured childhood cancer patients from St. Jude Children’s Research Hospital. To better understand the ongoing identification processes within and among the various modalities of American cancer rhetoric, this dissertation expands upon several theories of constitutive rhetoric. First, it utilizes an extended concept of constitutive metaphors to properly ascertain the identification and ideological power of the martial and space exploration metaphoric frameworks underlying the “War on Cancer” and the “Cancer Moonshot Initiative.” Second, it positions the pink ribbon and yellow bracelet of American cancer culture as iconic objects and locates their identificatory and ideological impact as emanating from their constitutive materiality. Finally, this study advances a narrative-based framework for understanding the constitutive corporality of cancered bodies in media. By attending to the physical contours of cancered bodies, this study effectively demonstrates the identity and ideological force of such bodies. Overarchingly, however, this dissertation contributes to a more nuanced understanding of constitutive theory through its focus upon cancer’s paradoxical status as an “invisible illness.” That is, although initially invisible, cancer transforms into a highly visible disease when medically treated – and this tension between what is visible and what is not, and its impact on processes of identification – demonstrates the latent power of invisibility in constitutive rhetorics

    From Maya Pyramids to Paleoindian Projectile Points: the Importance of Public Outreach in Archaeology

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    Public outreach in archaeology can have a valuable impact on education, culture, society and even on the economy. However, it should not be relegated to the addendum of our research projects. Here we present two case studies that the authors have been actively involved in where outreach was a central part of the investigations. Following this, we outline a basic framework for conducting outreach in both the short- and long-term. While these are not perfect examples, they are intended to get archaeologists, as a community, thinking about the real and practical implications of conducting public outreach. Beyond the educational value, it is important to recognize the economic implication of our work to local communities. If we do not communicate the value of our research, then we have only ourselves to blame

    Epithelial-mesenchymal transdifferentiation in pediatric lens epithelial cells

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    PURPOSE. Posterior capsule opacification (PCO) is a complication after cataract surgery, particularly in children. Epithelial-mesenchymal transition (EMT) of lens epithelial cells, mediated by transforming growth factor beta (TGF beta), contributes to PCO. However, its pathogenesis in children is poorly understood. We correlated cell growth in culture with patient characteristics, studied gene expression of pediatric lens epithelial cells (pLEC), and examined the effects of TGF beta-2 on these cells in vitro. METHODS. Clinical characteristics of children with cataracts correlated with growth behavior of pLEC in vitro. mRNA expression of epithelial (alpha B-crystallin, connexin-43) and mesenchymal (alpha(V)-integrin, alpha-smooth muscle actin, collagen-I alpha 2, fibronectin-1) markers was quantified in pLEC and in cell line HLE-B3 in the presence and absence of TGF beta-2. RESULTS. Fifty-four anterior lens capsules from 40 children aged 1 to 180 months were obtained. Cell outgrowth occurred in 44% of the capsules from patients <= 12 months and in 33% of capsules from children aged 13 to 60 months, but in only 6% of capsules from children over 60 months. TGF beta-2 significantly upregulated expression of alpha B-crystallin (HLE-B3), alpha(V)-integrin (HLE-B3), collagen-I alpha 2, and fibronectin-1 (in pLEC and HLE-B3 cells). CONCLUSIONS. Patient characteristics correlated with growth behavior of pLEC in vitro, paralleling a higher clinical incidence of PCO in younger children. Gene expression profiles of pLEC and HLE-B3 suggest that upregulation of alpha(V)-integrin, collagen-I alpha 2, and fibronectin-1 are involved in EMT

    Structural modifications of low-energy heavy-ion irradiated germanium

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    Heavy-ion irradiation of crystalline germanium (c-Ge) results in the formation of a homogeneous amorphous germanium (a-Ge) layer at the surface. This a-Ge layer undergoes structural modification such as a strong volume expansion accompanied by drastic surface blackening with further ion irradiation. In the present paper we investigate the mechanism of this ion-induced structural modification in a-Ge basically for the irradiation with I ions (3 and 9 MeV) at room and low temperature as a function of ion fluence for the ion incidence angles of Θ=7 and Θ=45. For comparison, Ag- and Au-ion irradiations were performed at room temperature as a function of the ion fluence. At fluences two orders of magnitude above the amorphization threshold, morphological changes were observed for all irradiation conditions used. Over a wide range of ion fluences we demonstrate that the volume expansion is caused by the formation of voids at the surface and in the depth of the projected ion range. At high ion fluences the amorphous layer transforms into a porous structure as established by cross section and plan view electron microscopy investigations. However, the formation depth of the surface and buried voids as well as the shape and the dimension of the final porous structure depend on the ion fluence, ion species, and irradiation temperature and will be discussed in detail. The rate of the volume expansion (i.e., porous layer formation) depends linearly on the value of Δn. This clearly demonstrates that the structural changes are determined solely by the nuclear energy deposited within the amorphous phase. In addition, at high ion fluences all perpendicular ion irradiations lead to a formation of a microstructure at the surface, whereas for nonperpendicular ion irradiations a nonsaturating irreversible plastic deformation (ion hammering) without a microstructure formation is observed. For the irradiation with ion energies of several MeV, the effect of plastic deformation shows a linear dependence on the ion fluence. Based on these results, we provide an explanation for the differences in surface morphology observed for different angles of incidence of the ion beam will be discussed in detail

    Multi-Frequency Synthesis of VLBI Images Using a Generalized Maximum Entropy Method

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    A new multi-frequency synthesis algorithm for reconstructing images from multi-frequency VLBI data is proposed. The algorithm is based on a generalized maximum-entropy method, and makes it possible to derive an effective spectral correction for images over a broad frequency bandwidth, while simultaneously reconstructing the spectral-index distribution over the source. The results of numerical simulations demonstrating the capabilities of the algorithm are presented.Comment: 17 pages, 8 figure

    Low contrast visual acuity testing is associated with cognitive performance in multiple sclerosis: a cross-sectional pilot study

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    Background: Cognitive impairment and visual deterioration are two key clinical symptoms in MS and affect 50 to 80% of patients. Little is known about the influence of cognitive impairment on visual tests recommended for MS such as low contrast sensitivity testing. Our objective was to investigate whether low contrast sensitivity testing is influenced by cognitive impairment in multiple sclerosis (MS) patients. Methods: Cross-sectional study including 89 patients with relapsing-remitting MS. All patients received cognitive evaluation using Rao’s Brief Repeatable Battery of Neuropsychological Testing (BRB-N). Visual assessments included low contrast sensitivity (CS) by functional acuity contrast testing and high contrast visual acuity (VA) using ETDRS charts. Retinal morphology as visual impairment correlate was measured using retinal nerve fiber layer (RNFL) thickness by optical coherence tomography. Results: In combined analyses using generalized estimating equation models, Paced Auditory Serial Addition Test (PASAT) and RNFL as well as and the Symbol Digit Modalities Test (SDMT) and RNFL predicted CS. To further control for a potential influence of the anterior visual system we performed partial correlation analyses between visual function and cognitive function test results but controlling for RNFL. Even when controlling for RNFL, CS was associated with PASAT performance and SDMT performance. Conclusion: Our data show that: a) cognitive impairment and performance in visual function tests such as low contrast sensitivity testing are associated; b) the main cognitive domains correlating with visual test performance are information processing speed and, to a lesser degree, memory; This preliminary data needs to be substantiated in further studies investigating patients with a higher cognitive burden, healthy controls and in longitudinal settings

    Quantifying potential particulate matter intake dose in a low-income community in South Africa

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    Understanding how exposure to particulate matter impacts human health is complex. Personal exposure is a function of the pollution concentrations measured at any given place and time. The health impacts of this exposure are, in part, determined by how high pollutant concentrations are and how much pollution can potentially enter the body. This study considered data gathered in the winter of 2013 in a low-income community on the Mpumalanga Highveld, South Africa, which is a geographical area known for its high air pollution levels. Data collected by GPS monitors worn by individuals in the community were used to understand in which microenvironments people spend most of their time. Participants spent time in five main micro-environments: (highest rank first) inside a house, directly outside a house, on a dirt road, on a tar road, and on an open field. Eight days’ worth of ambient, indoor and personal particulate matter measurements were paired with individual GPS positioning data for one study participant. We identified pollutant concentrations where the person spent time and how much particulate matter the person potentially inhaled. Highest concentrations were measured inside the dwelling and directly outside the dwelling of the individual. When comparing directly (ranging from 0.02 – 0.76 mg) - and indirectly (0.02 – 0.34 mg) derived time-weighted potential intake doses, directly derived intake doses were higher and more likely to represent how much particulate matter was potentially inhaled by the participant. This study suggests that people living in communities on the Mpumalanga Highveld are exposed to unacceptably high air pollution levels in places in which they spend most of their time. Direct exposure and intake dose assessments are an important element of environmental health studies to supplement data collected by stationary monitors in order to better understand exactly what people are breathing.https://cleanairjournal.org.zaam2022Geography, Geoinformatics and Meteorolog
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