943 research outputs found

    Ordovician volcanic and hypabyssal rocks in the central and southern Miramichi Highlands: their tectonic setting and relationship to contemporary volcanic rocks in northern New Brunswick

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    New analyses of mafic igneous rocks from the central Miramichi Highlands have led us to modify the interpretation of its tectonic setting. New samples have been obtained from the Bam ford Brook and Trousers Lake areas of New Brunswick, and the Danforth area in Maine. All subalkalic mafic rocks, including the Trousers Lake striped amphibolites, are associated with a thick sequence of metasedimentary rocks and all are continental tholeiites, analogous to tholeiitic suites in the Tetagouche Group of the northern Miramichi Highlands. The presence of alkalic basalt and comendite in this area supports this correlation. In the southern Miramichi Highlands of Maine, silicic and intermediate volcanic rocks form part of the Woodstock-Meductic arc-related volcanic suite. RÉSUMÉ De nouvelles analyses de roches ignées mafiques provenant du centre des hautes-terres de la Miramichi nous ont conduit à modifier l’interprétation de leur environnement tectonique. De nouveaux échantillons ont été recueillis dans les régions du ruisseau Bamford et du lac Trousers au Nouveau-Brunswick, et dans la région de Danforth au Maine. Toutes les roches mafiques subalcalines, incluant les amphibolites rubannées du lac Trousers, sont associées avec une séquence épaisse de roches métasédimentaires et sont toutes des tholéiites continentales, similaires aux suites tholéiitiques appartenant au Groupe de Tétagouche du nord des hautes-terres de la Miramichi. La présence de basaltes alcalins et de comendites dans cette région appuie cette corrélation. Dans le sud des hautes-terres de la Miramichi au Maine, les volcanites siliceuses et inlermddiaires constituent une partie de la suite volcanique d'arc de Woodstock-Meductic. [Traduit par le journal

    The impact of supraglacial debris on proglacial runoff and water chemistry

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    Debris is known to influence the ablation, topography and hydrological systems of glaciers. This paper determines for the first time how these influences impact on bulk water routing and the proglacial runoff signal, using analyses of supraglacial and proglacial water chemistry and proglacial discharge at Miage Glacier, Italian Alps. Debris does influence the supraglacial water chemistry, but the inefficient subglacial system beneath the debris-covered zone also plays a role in increasing the ion contribution to the proglacial stream. Daily hydrographs had a lower amplitude and later discharge peak compared to clean glaciers and fewer diurnal hydrographs were found compared to similar analysis for Haut Glacier d’Arolla. We attribute these observations to the attenuating effect of the debris on ablation, smaller input streams on the debris-covered area, a less efficient subglacial system, and possible leakage into a raised sediment bed beneath the glacier. Strongly diurnal hydrographs are constrained to periods with warmer than average conditions. ‘Average’ weather conditions result in a hydrograph with reverse asymmetry. Conductivity and discharge commonly show anti-clockwise hysteresis, suggesting the more dilute, rapidly-routed melt component from the mid-glacier peaks before the discharge peak, with components from higher up-glacier and the debris-covered areas arriving later at the proglacial stream. The results of this study could lead to a greater understanding of the hydrological structure of other debris-covered glaciers, with findings highlighting the need to include the influence of the debris cover within future models of debris-covered glacier runoff

    Collagen α1(XI) in Normal and Malignant Breast Tissue

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    Little is known about collagen XI expression in normal and malignant breast tissue. Tissue microarrays, constructed from 72 patients with breast carcinoma and matched normal tissue, were immunohistochemically stained with five antisera against isoform-specific regions of collagen α1(XI) N-terminal domain. Staining intensity was graded on a 0–3 scale in epithelial cytoplasm, stroma, and endothelial staining of the vasculature of each tissue core. The staining was compared to known pathologic parameters: age, tumor size, overall tumor grade, nuclear grade, tubule formation, mitotic counts, angiolymphatic invasion, node status, estrogen receptor status, progesterone receptor status, and HER-2/neu status. Estrogen and progesterone receptor status were used as a control for comparison. With antisera V1a and amino propeptide (Npp), stroma surrounding cancerous cells was found to have decreased collagen α1(XI) staining compared to stroma adjacent to normal epithelium (P=0.0006, P\u3c 0.0001). Collagen α1(XI) staining with V1a antiserum in cytoplasm of cancer cells demonstrated decreased intensity in metastasized primary tumors when compared to nonmetastasized primary tumors (P=0.009). Cytoplasmic staining with Npp antiserum in cancer demonstrated an inverse relationship to positive estrogen receptor status in cancer (P=0.012) and to progesterone receptor status (P=0.044). Stromal staining for Npp in cancerous tissue demonstrated an inverse relationship with tubule formation score (P=0.015). This is the first study to localize collagen XI within normal and malignant breast tissue. Collagen α1(XI) appears to be downregulated in stroma surrounding breast cancer. Detection of collagen XI in breast tissue may help predict women who have lymph node metastases

    Enabling nursing students to focus on the Ottawa Charter and the nurses role in tackling inequalities in health through international exchange

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    Student nurses in a transatlantic exchange program explored the role of registered nurses in five countries’ public health systems. The Ottawa Charter provided a framework for students to examine the nurse’s responsibilities in public health. Students took practice placements in geographically rural areas on another continent and explored inequalities in health care. If nurses are to understand their role in the health care system then they must be taught the scope of their practice including their role in health promotion, public health practice and community development. For this project nursing instructors developed an assignment relevant to the aims and suitable for students in all five nursing programs. Only three of 48 students offered an assignment which focused on building healthy public policy. Nurse educators need to explore this further to ensure nurses of the future are aware of their role and responsibilities in this area and have skills to work effectively to influence and build healthy policy. The international student exchange supported the students’ developing understanding of the breadth of initiatives around the globe where nurses are actively engaged in addressing inequalities of health. Findings from an analysis of their assignments are presented in this evaluative report

    A Small Molecule Inhibitor of PDK1/PLC gamma 1 Interaction Blocks Breast and Melanoma Cancer Cell Invasion

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    Strong evidence suggests that phospholipase Cγ1 (PLCγ1) is a suitable target to counteract tumourigenesis and metastasis dissemination. We recently identified a novel signalling pathway required for PLCγ1 activation which involves formation of a protein complex with 3-phosphoinositide-dependent protein kinase 1 (PDK1). In an effort to define novel strategies to inhibit PLCγ1-dependent signals we tested here whether a newly identified and highly specific PDK1 inhibitor, 2-O-benzyl-myo-inositol 1,3,4,5,6-pentakisphosphate (2-O-Bn-InsP5), could affect PDK1/PLCγ1 interaction and impair PLCγ1-dependent cellular functions in cancer cells. Here, we demonstrate that 2-O-Bn-InsP5 interacts specifically with the pleckstrin homology domain of PDK1 and impairs formation of a PDK1/PLCγ1 complex. 2-O-Bn-InsP5 is able to inhibit the epidermal growth factor-induced PLCγ1 phosphorylation and activity, ultimately resulting in impaired cancer cell migration and invasion. Importantly, we report that 2-O-Bn-InsP5 inhibits cancer cell dissemination in zebrafish xenotransplants. This work demonstrates that the PDK1/PLCγ1 complex is a potential therapeutic target to prevent metastasis and it identifies 2-O-Bn-InsP5 as a leading compound for development of anti-metastatic drugs

    A Mixed-Mode Examination of the Teaching of Lead Climbing by Adventure Sports Coaches in the UK

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    Background: We present a unique study of adventure sports coaches teaching lead climbing. Expanding existing work on judgement and decision making, we examine the coaching process and the decision making employed to manage the pedagogical and security needs of climbers when they are being introduced to lead climbing. Research design and data collection: As part of a mixed approach, an Applied Cognitive Task Analysis was initially conducted on a small sample of expert coaches (n=7) before a questionnaire was designed and administered with a larger sample (n=53). Findings: The study identifies that the tuition of lead climbing is built on nine core elements that form a shared mental model which in turn is individualised to meet the needs and demands of the individual learning to lead climb. The existence of this coherent shared mental model displays minor modifications to reflect the coach’s own climbing background. More importantly, the existence of this shared mental model is derived from the instructors’ own experiences of climbing and teaching lead climbing rather than any formalised training. In short, this model is actualised through an informal community of practice. Conclusion: The implication for training instructors is that the skills of adapting these nine core aspects to meet individual needs should also be given due consideration alongside the technical skills of rope work and security

    First LIGO search for gravitational wave bursts from cosmic (super)strings

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    We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR

    Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

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    We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
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