203 research outputs found

    The Road that Made Mountains: Highway Design and the Production of Landscape in Vail, Colorado

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    Constructed between 1972 and 1978, Vail Pass is a 16-mile section of Interstate-70 that crosses the continental divide in the Central Mountains of Colorado. It connects the ski resort communities of Copper Mountain and Vail and has played a significant role in the development of tourism in the Colorado High Country. The design and planning of Vail Pass occurred at a time of increased public concern over environmental issues, and was built following a series of significant pieces of federal environmental legislation. Within this context, highway designers and engineers sought to harmoniously integrate the highway into its natural setting. This thesis tells the story of Vail Pass through the perspectives of environmental legislation and politics, roadway design, and human-nature relations in Colorado. A personal bicycle journey over Vail Pass serves to introduce the central questions of this project. Chapter one discusses scholarly work within environmental history and landscape studies in order to contextualize this project within broader academic debates. Chapter two addresses the environmental politics and legislation that arose around the Vail Pass project and considers the impact of federal legislation on a single landscape. In Chapters three and four, Vail Pass is placed within broader histories of road and landscape design, providing a deeper understanding of the meaning and significance of the Vail Pass landscape. In the concluding chapter, Vail Pass is used to discuss broader questions of infrastructure, tourism, and the environment in Colorado as climate change alters the landscape

    GBM heterogeneity as a function of variable epidermal growth factor receptor variant III activity.

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    Abnormal activation of the epidermal growth factor receptor (EGFR) due to a deletion of exons 2-7 of EGFR (EGFRvIII) is a common alteration in glioblastoma (GBM). While this alteration can drive gliomagenesis, tumors harboring EGFRvIII are heterogeneous. To investigate the role for EGFRvIII activation in tumor phenotype we used a neural progenitor cell-based murine model of GBM driven by EGFR signaling and generated tumor progenitor cells with high and low EGFRvIII activation, pEGFRHi and pEGFRLo. In vivo, ex vivo, and in vitro studies suggested a direct association between EGFRvIII activity and increased tumor cell proliferation, decreased tumor cell adhesion to the extracellular matrix, and altered progenitor cell phenotype. Time-lapse confocal imaging of tumor cells in brain slice cultures demonstrated blood vessel co-option by tumor cells and highlighted differences in invasive pattern. Inhibition of EGFR signaling in pEGFRHi promoted cell differentiation and increased cell-matrix adhesion. Conversely, increased EGFRvIII activation in pEGFRLo reduced cell-matrix adhesion. Our study using a murine model for GBM driven by a single genetic driver, suggests differences in EGFR activation contribute to tumor heterogeneity and aggressiveness

    Aberration-like cusped focusing in the post-paraxial Talbot effect

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    We present an analysis of self-imaging in a regime beyond the paraxial, where deviation from simple paraxial propagation causes apparent self-imaging aberrations. The resulting structures are examples of aberration without rays and are described analytically using post-paraxial theory. They are shown to relate to, but surprisingly do not precisely replicate, a standard integral representation of a diffraction cusp. Beyond the Talbot effect, this result is significant as it illustrates that the effect of aberration -- as manifested in the replacement of a perfect focus with a cusp-like pattern -- can occur as a consequence of improving the paraxial approximation, rather than due to imperfections in the optical system.Comment: 8 pages, 3 figures, IoP styl

    Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces

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    Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 Β± 90 nm) compared to the SAM (Rq = 2.8 Β± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface

    In situ polymerisation of isoeugenol as a green consolidation method for waterlogged archaeological wood

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    Waterlogged archaeological wood is often in need of consolidation prior to drying to prevent shrinkage and cracking of the object. There is a need for new greener materials (than for example polyethylene glycol) and methods for consolidation to be developed. The use of wood-based components could provide good interaction between the consolidant and the remaining wood structure and would also support a shift away from fossil fuel-based materials to those with more sustainable sources. Based on this, lignin-like structures have been investigated for their ability to consolidate waterlogged archaeological wood. The in situ formation of a lignin-like material has been carried out using isoeugenol polymerised by horse radish peroxidase in aqueous solution. The formation of the oligomeric/polymeric materials within the wood following this reaction has been determined by Attenuated Total Reflectance Fourier Transform Infra Red (ATR-FTIR) spectroscopy. The oligomers remaining in solution have been characterised by ATR-FTIR and nuclear magnetic resonance (NMR) spectroscopy as well as analytical ultracentrifugation, showing that they have a weight average Mw of 0.4–0.9 kDa and a lignin-like structure rich in the Ξ²-5β€² moiety. Therefore, this approach is proposed as a basis to further develop a green consolidation method for waterlogged archaeological wood

    Bone Microenvironment Specific Roles of ITAM Adapter Signaling during Bone Remodeling Induced by Acute Estrogen-Deficiency

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    Immunoreceptor tyrosine-based activation motif (ITAM) signaling mediated by DAP12 or FcΞ΅ receptor IΞ³ chain (FcRΞ³) have been shown to be critical for osteoclast differentiation and maturation under normal physiological conditions. Their function in pathological conditions is unknown. We studied the role of ITAM signaling during rapid bone remodeling induced by acute estrogen-deficiency in wild-type (WT), DAP12-deficient (DAP12-/-), FcRΞ³-deficient (FcRΞ³-/-) and double-deficient (DAP12-/-FcRΞ³-/-) mice. Six weeks after ovariectomy (OVX), DAP12-/-FcRΞ³-/- mice showed resistance to lumbar vertebral body (LVB) trabecular bone loss, while WT, DAP12-/- and FcRΞ³-/- mice had significant LVB bone loss. In contrast, all ITAM adapter-deficient mice responded to OVX with bone loss in both femur and tibia of approximately 40%, relative to basal bone volumes. Only WT mice developed significant cortical bone loss after OVX. In vitro studies showed microenvironmental changes induced by OVX are indispensable for enhanced osteoclast formation and function. Cytokine changes, including TGFΞ² and TNFΞ±, were able to induce osteoclastogenesis independent of RANKL in BMMs from WT but not DAP12-/- and DAP12-/-FcRΞ³-/- mice. FSH stimulated RANKL-induced osteoclast differentiation from BMMs in WT, but not DAP12-/- and DAP12-/-FcRΞ³-/- mice. Our study demonstrates that although ITAM adapter signaling is critical for normal bone remodeling, estrogen-deficiency induces an ITAM adapter-independent bypass mechanism allowing for enhanced osteoclastogenesis and activation in specific bony microenvironments

    Whole Slide Imaging Versus Microscopy for Primary Diagnosis in Surgical Pathology: A Multicenter Blinded Randomized Noninferiority Study of 1992 Cases (Pivotal Study)

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    Most prior studies of primary diagnosis in surgical pathology using whole slide imaging (WSI) versus microscopy have focused on specific organ systems or included relatively few cases. The objective of this study was to demonstrate that WSI is noninferior to microscopy for primary diagnosis in surgical pathology. A blinded randomized noninferiority study was conducted across the entire range of surgical pathology cases (biopsies and resections, including hematoxylin and eosin, immunohistochemistry, and special stains) from 4 institutions using the original sign-out diagnosis (baseline diagnosis) as the reference standard. Cases were scanned, converted to WSI and randomized. Sixteen pathologists interpreted cases by microscopy or WSI, followed by a wash-out period of β‰₯4 weeks, after which cases were read by the same observers using the other modality. Major discordances were identified by an adjudication panel, and the differences between major discordance rates for both microscopy (against the reference standard) and WSI (against the reference standard) were calculated. A total of 1992 cases were included, resulting in 15,925 reads. The major discordance rate with the reference standard diagnosis was 4.9% for WSI and 4.6% for microscopy. The difference between major discordance rates for microscopy and WSI was 0.4% (95% confidence interval, -0.30% to 1.01%). The difference in major discordance rates for WSI and microscopy was highest in endocrine pathology (1.8%), neoplastic kidney pathology (1.5%), urinary bladder pathology (1.3%), and gynecologic pathology (1.2%). Detailed analysis of these cases revealed no instances where interpretation by WSI was consistently inaccurate compared with microscopy for multiple observers. We conclude that WSI is noninferior to microscopy for primary diagnosis in surgical pathology, including biopsies and resections stained with hematoxylin and eosin, immunohistochemistry and special stains. This conclusion is valid across a wide variety of organ systems and specimen types

    Estrogen/Estrogen Receptor Alpha Signaling in Mouse Posterofrontal Cranial Suture Fusion

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    BACKGROUND: While premature suture fusion, or craniosynostosis, is a relatively common condition, the cause is often unknown. Estrogens are associated with growth plate fusion of endochondral bones. In the following study, we explore the previously unknown significance of estrogen/estrogen receptor signaling in cranial suture biology. METHODOLOGY/PRINCIPAL FINDINGS: Firstly, estrogen receptor (ER) expression was examined in physiologically fusing (posterofrontal) and patent (sagittal) mouse cranial sutures by quantitative RT-PCR. Next, the cranial suture phenotype of ER alpha and ER beta knockout (alphaERKO, betaERKO) mice was studied. Subsequently, mouse suture-derived mesenchymal cells (SMCs) were isolated; the effects of 17-beta estradiol or the estrogen antagonist Fulvestrant on gene expression, osteogenic and chondrogenic differentiation were examined in vitro. Finally, in vivo experiments were performed in which Fulvestrant was administered subcutaneously to the mouse calvaria. Results showed that increased ERalpha but not ERbeta transcript abundance temporally coincided with posterofrontal suture fusion. The alphaERKO but not betaERKO mouse exhibited delayed posterofrontal suture fusion. In vitro, addition of 17-beta estradiol enhanced both osteogenic and chondrogenic differentiation in suture-derived mesenchymal cells, effects reversible by Fulvestrant. Finally, in vivo application of Fulvestrant significantly diminished calvarial osteogenesis, inhibiting suture fusion. CONCLUSIONS/SIGNIFICANCE: Estrogen signaling through ERalpha but not ERbeta is associated with and necessary for normal mouse posterofrontal suture fusion. In vitro studies suggest that estrogens may play a role in osteoblast and/or chondrocyte differentiation within the cranial suture complex

    TBK1: a new player in ALS linking autophagy and neuroinflammation.

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    Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disorder affecting motor neurons, resulting in progressive muscle weakness and death by respiratory failure. Protein and RNA aggregates are a hallmark of ALS pathology and are thought to contribute to ALS by impairing axonal transport. Mutations in several genes known to contribute to ALS result in deposition of their protein products as aggregates; these include TARDBP, C9ORF72, and SOD1. In motor neurons, this can disrupt transport of mitochondria to areas of metabolic need, resulting in damage to cells and can elicit a neuroinflammatory response leading to further neuronal damage. Recently, eight independent human genetics studies have uncovered a link between TANK-binding kinase 1 (TBK1) mutations and ALS. TBK1 belongs to the IKK-kinase family of kinases that are involved in innate immunity signaling pathways; specifically, TBK1 is an inducer of type-1 interferons. TBK1 also has a major role in autophagy and mitophagy, chiefly the phosphorylation of autophagy adaptors. Several other ALS genes are also involved in autophagy, including p62 and OPTN. TBK1 is required for efficient cargo recruitment in autophagy; mutations in TBK1 may result in impaired autophagy and contribute to the accumulation of protein aggregates and ALS pathology. In this review, we focus on the role of TBK1 in autophagy and the contributions of this process to the pathophysiology of ALS
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