726 research outputs found

    Connecting Cape Breton Island and Newfoundland, Canada: Geophysical Modeling of pre-Carboniferous 'Basement' Rocks in the Cabot Strait Area

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    Magnetic and gravity data from northeastern Cape Breton Island, southwestern Newfoundland, and the intervening Cabot Strait area were compiled and used to generate a series of maps displaying magnetic (filtered total field, first and second derivative) and gravity (Bouguer anomaly onshore, free-air anomaly offshore) information to enhance the anomaly pattern associated with regional geology. With further constraints from previously published seismic reflection interpretations and detailed maps of onshore geology, five two-dimensional subsurface models were generated.  Potential field anomalies in the offshore can be correlated with onshore faults, rock units, and pre-Carboniferous terranes.  In Newfoundland, the Cabot – Long Range Fault separates Grenvillian basement to the northwest from peri-Gondwanan Port aux Basques subzone basement in the southeast and can be traced to the Wilkie Brook Fault on Cape Breton Island.  The Cape Ray Fault/Red Indian Line merges offshore with the Cabot – Long Range Fault so that Notre Dame subzone rocks do not extend across the Cabot Strait area.  The Port aux Basques – Exploits subzone boundary crosses the strait but is likely buried by younger rocks onshore in Cape Breton Island.  Magnetic halos in the Exploits subzone are probably caused by Silurian – Devonian plutons like those in the Burgeo Intrusive Suite. The Exploits – Bras d’Or terrane boundary is located within the Ingonish magnetic anomaly, which was resolved into four overlapping components representing basement sources intruded into metasedimentary rocks and dioritic and granodioritic plutons of the Bras d’Or terrane.  The Bras d’Or terrane can be traced to the Cinq-Cerf block and Grey River areas in southern Newfoundland.  The interpretations suggest that Bras d’Or terrane ‘basement’ may underlie all of Exploits subzone, and that the Aspy terrane of Cape Breton Island is part of that subzone. SOMMAIRELes donnĂ©es magnĂ©tomĂ©triques et gravimĂ©triques du nord-est de l’üle du Cap-Breton, dans le sud-ouest de Terre-Neuve, et de la rĂ©gion du dĂ©troit de Cabot contigu, ont Ă©tĂ© compilĂ©es et utilisĂ©es pour produire une sĂ©rie de cartes affichant les particularitĂ©s magnĂ©tiques (champ total filtrĂ©, dĂ©rivĂ© premiĂšre et seconde) et gravimĂ©triques (anomalie de Bouguer de la cĂŽte, anomalie Ă  l’air libre extracĂŽtiĂšre) pour ajouter Ă  la comprĂ©hension des motifs d’anomalie de la gĂ©ologie rĂ©gionale.  En tenant compte des limitations imposĂ©es par les interprĂ©tations de donnĂ©es de levĂ©s de sismique rĂ©flexion dĂ©jĂ  publiĂ©es et de cartes dĂ©taillĂ©es de gĂ©ologie continentale, cinq modĂšles 2D du sous-sol ont Ă©tĂ© produits.  Des anomalies de champ potentiel en zone extracĂŽtiĂšre peuvent ĂȘtre corrĂ©lĂ©es avec des failles, des unitĂ©s lithologiques et des terranes prĂ©-carbonifĂšres sur la cĂŽte.   Sur l’üle de Terre-Neuve, la faille de Cabot-Long Range qui sĂ©pare le socle grenvillien au nord-ouest de la sous-zone de socle pĂ©ri-gondwanienne, de Port-aux- Basques au sud-est, peut ĂȘtre reliĂ©e Ă  la faille de Wilkie Brook sur l’üle du Cap-Breton.  La faille du Cap Ray et la linĂ©ation de Red Indian se fondent au large avec la faille de Cabot – Long  Range, ce qui signifie que les roches de la sous-zone de Notre-Dame ne traversent pas la rĂ©gion du dĂ©troit de Cabot.  La limite de la sous-zone de Port aux Basques-Exploits traverse le dĂ©troit, mais elle est vraisemblablement enfouie sous des roches plus jeunes sur l’üle du Cap-Breton.  Les halos magnĂ©tiques dans la sous-zone Exploits sont probablement causĂ©s par des plutons siluro-dĂ©voniens comme c’est le cas de ceux de la sĂ©quence intrusive de Burgeo.  La limite du terrane Exploits-Bras d’Or est situĂ©e dans l’anomalie magnĂ©tique Ingonish, laquelle s’est rĂ©vĂ©lĂ©e ĂȘtre constituĂ©e de quatre composantes superposĂ©es reprĂ©sentant des sources de socle engoncĂ©es dans des roches mĂ©tasĂ©dimentaires, et dans des plutons dioritiques et granodioritiques du terrane de Bras d’Or.  On peut suivre le terrane de Bras d’Or jusque dans les rĂ©gions du bloc de Cinq-Cerf et de Grey River dans le sud de Terre-Neuve.  Les interprĂ©tations permettent de penser que le « socle » du terrane de Bras d’Or pourrait constituer l’assise rocheuse de la sous-zone Exploits, et que le terrane Aspy de l’üle du Cap-Breton ferait partie de cette sous-zone

    Panel IV: The Appropriations Power and the Necessary and Proper Clause

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    We are going to talk about some of the coercive aspects that the Constitution, in a sense, gives to the Congress, because there are some constitutional powers given to the Congress which directly relate to how the executive branch does its job

    Critical Event Review Team (CERT)

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    The culture of medicine is shifting from placing blame on providers to a systems-minded culture of trying to understand human error as a symptom of deeper rooted systemic issues. The goal is to reduce harm by redesigning the systems in which humans work

    Military personnel with chronic symptoms following blast traumatic brain injury have differential expression of neuronal recovery and epidermal growth factor receptor genes

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    Objective: Approximately one-quarter of military personnel who deployed to combat stations sustained one or more blast-related, closed-head injuries. Blast injuries result from the detonation of an explosive device. The mechanisms associated with blast exposure that give rise to traumatic brain injury (TBI), and place military personnel at high risk for chronic symptoms of post-concussive disorder (PCD), post-traumatic stress disorder (PTSD), and depression are not elucidated. Methods: To investigate the mechanisms of persistent blast-related symptoms, we examined expression profiles of transcripts across the genome to determine the role of gene activity in chronic symptoms following blast-TBI. Active duty military personnel with (1) a medical record of a blast-TBI that occurred during deployment (n = 19) were compared to control participants without TBI (n = 17). Controls were matched to cases on demographic factors including age, gender, and race, and also in diagnoses of sleep disturbance, and symptoms of PTSD and depression. Due to the high number of PCD symptoms in the TBI+ group, we did not match on this variable. Using expression profiles of transcripts in microarray platform in peripheral samples of whole blood, significantly differentially expressed gene lists were generated. Statistical threshold is based on criteria of 1.5 magnitude fold-change (up or down) and p-values with multiple test correction (false discovery rate \u3c0.05). Results: There were 34 transcripts in 29 genes that were differentially regulated in blast-TBI participants compared to controls. Up-regulated genes included epithelial cell transforming sequence and zinc finger proteins, which are necessary for astrocyte differentiation following injury. Tensin-1, which has been implicated in neuronal recovery in pre-clinical TBI models, was down-regulated in blast-TBI participants. Protein ubiquitination genes, such as epidermal growth factor receptor, were also down-regulated and identified as the central regulators in the gene network determined by interaction pathway analysis. Conclusion: In this study, we identified a gene-expression pathway of delayed neuronal recovery in military personnel a blast-TBI and chronic symptoms. Future work is needed to determine if therapeutic agents that regulate these pathways may provide novel treatments for chronic blast-TBI-related symptoms

    Impacts of tourism on coastal areas

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    The socioeconomics of the Anthropocene are exposing coastal regions to multiple pressures, including climate change hazards, resource degradation, urban development, and inequality. Tourism is often raised as either a panacea to, or exacerbator of, such threats to ecosystems and sustainable livelihoods. To better understand the impacts of tourism on coastal areas, Scopus and Web of Science databases were searched for the top-100 cited papers on coastal tourism. Web of Science suggested ‘highly cited’ papers were also included to allow for more recent high impact papers. Of the papers retrieved, forty-four focused on the impacts of tourism. Social/cultural and environmental impacts were viewed as mostly negative, while economic impacts were viewed as mostly positive but only of actual benefit to a few. In addition, when compared with recent whole-of-sector reviews and reports it was evident that coastal tourism is increasingly a global enterprise dominated by large corporations that leverage various interests across local to transnational scales. Through this global enterprise, even the positive economic benefits identified were overshadowed by a broader system of land and property development fuelling local wealth inequity and furthering the interests of offshore beneficiaries. Only two highly cited papers discussed tourism within a broader context of integrated coastal zone management, suggesting that tourism is mostly assessed as a discrete sector within the coastal zone and peripheral to other coastal management considerations or the global tourism sector as a whole. The findings have relevance to the holistic management of coasts, coastal tourism, and the achievement of sustainable development goals in a way that considers the increasing threats from coastal hazards, resource extraction and urbanisation, as well as the pervasive impacts of international business systems from local to global scales

    Evidence for Neutrino Oscillations from Muon Decay at Rest

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    A search for nu_bar_mu to nu_bar_e oscillations has been conducted at the Los Alamos Meson Physics Facility using nu_bar_mu from mu+ decay at rest. The nu_bar_e are detected via the reaction (nu_bar_e,p) -> (e+,n), correlated with the 2.2 MeV gamma from (n,p) -> (d,gamma). The use of tight cuts to identify e+ events with correlated gamma rays yields 22 events with e+ energy between 36 and 60 MeV and only 4.6 (+/- 0.6) background events. The probability that this excess is due entirely to a statistical fluctuation is 4.1E-08. A chi^2 fit to the entire e+ sample results in a total excess of 51.8 (+18.7) (-16.9) (+/- 8.0) events with e+ energy between 20 and 60 MeV. If attributed to nu_bar_mu -> nu_bar_e oscillations, this corresponds to an oscillation probability (averaged over the experimental energy and spatial acceptance) of 0.0031 (+0.0011) (-0.0010) (+/- 0.0005).Comment: 57 pages, 34 figures, revtex, additional information available at http://nu1.lampf.lanl.gov/~lsnd

    String or M theory axion as a quintessence

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    A slow-rolling scalar field (Q≡Q\equiv Quintessence) with potential energy VQ∌(3×10−3eV)4V_Q\sim (3\times 10^{-3} {\rm eV})^4 has been proposed as the origin of accelerating universe at present. We investigate the effective potential of QQ in the framework of supergravity model including the quantum corrections induced by generic (nonrenormalizable) couplings of QQ to the gauge and charged matter multiplets. It is argued that the K\"ahler potential, superpotential and gauge kinetic functions of the underlying supergravity model are required to be invariant under the variation of QQ with an extremely fine accuracy in order to provide a working quintessence potential. Applying these results for string or MM-theory, we point out that the heterotic MM-theory or Type I string axion can be a plausible candidate for quintessence if (i) it does not couple to the instanton number of gauge interactions not weaker than those of the standard model and (ii) the modulus partner Re(Z){\rm Re}(Z) of the periodic quintessence axion Im(Z)≡Im(Z)+1{\rm Im}(Z)\equiv {\rm Im}(Z)+1 has a large VEV: Re(Z)∌12πln⁥(m3/22MPlanck2/VQ){\rm Re}(Z)\sim \frac{1}{2\pi}\ln(m_{3/2}^2 M_{Planck}^2/V_Q). It is stressed that such a large Re(Z){\rm Re}(Z) gives the gauge unification scale at around the phenomenologically favored value 3×10163\times 10^{16} GeV. To provide an accelerating universe, the quintessence axion should be at near the top of its effective potential at present, which requires a severe fine tuning of the initial condition of QQ and Q˙\dot{Q} in the early universe. We discuss a late time inflation scenario based on the modular and CP invariance of the moduli effective potential, yielding the required initial condition in a natural manner if the K\"ahler metric of the quintessence axion superfield receives a sizable nonperturbative contribution.Comment: 23 pages, 3 figures, version to be published at Phys. Rev.

    How collective action produces psychological change and how that change endures over time: a case study of an environmental campaign

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    Previous research on collective action has suggested that both intra‐ and intergroup interactions are important in producing psychological change. In this study, we examine how these two forms of interaction relate to each other over time. We present results from a longitudinal ethnographic study of participation in an environmental campaign, documenting endurance and prevalence of psychological change. Participants, locals (n = 14) and self‐defined activists (n = 14), connected enduring psychological changes, such as changes in consumer behaviour and attitudes to their involvement in the environmental campaign. Thematic analysis of interviews suggested that participants linked the process of change to categorizing themselves in a new environmental‐activist way that influenced their everyday lives beyond the immediate campaign. This recategorization was a result of a conflictual intergroup relationship with the police. The intergroup interaction produced supportive within‐group relationships that facilitated the feasibility and sustainability of new world views that were maintained by staying active in the campaign. The data from the study support and extend previous research on collective action and are the basis of a model, suggesting that intragroup processes condition the effects of intergroup dynamics on sustained psychological change
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