2,312 research outputs found
Preliminary investigation of a major high-strain zone in the Caledonian Highlands, southern New Brunswick
A major ductile high-strain zone up to 5 km in width can be traced for at least 70 km diagonally across the Avalonian Caledonia terrane of southern New Brunswick. A study of the northeastern part of this zone from the Prosser Mountain area in the northwest to the Point Wolfe River area west of Fundy National Park shows that both the ca. 630-620 Ma Broad River Group and associated plutons and the 560-550 Ma Coldbrook Group contain similar structural elements, related to a largely shared deformational history. Some of this history is apparent also in the 560â550 Ma plutonic rocks. A pervasive foliation (S1) lies parallel to bedding (S0), and although evidently composite (S0-1) in the Broad River Group, this fabric is very heterogeneous in the younger Coldbrook Group, where low strain enclaves are widespread. No folds have been seen of an F1 generation, and no reversals of facing or vergence are apparent. A mineral lineation (L1m) is locally prominent. The plutonic rocks have early fabrics, including a foliation (S1) producing augen-gneiss with a prominent L-tectonite (L1m). S1 also includes a schistosity associated with the growth of white mica and breakdown of feldspar. Geometry suggests that S1 in the granites is related to S0-1 in the supracrustal rocks, and L1m in both units shares a common orientation. S1 and S0-1 are crenulated by a strong second cleavage (S2) axial planar to folds (F2), the large-scale expression of which is an asymmetric synform containing a belt of Coldbrook Group rocks. Kinematic indicators suggest an overall top-to-the-SE motion along thrusts that stack units of Broad River Group, Coldbrook Group, and plutonic rocks. Fabric development in the plutonic rocks implies a history of exhumation beginning under hot, anhydrous conditions, followed by hydration during retrogression as plutonic rocks were tectonically emplaced into this crustal stack. The age of these tectonic events is not yet well constrained, but could be as young as Carboniferous.
RĂSUMĂ
Il est possible de retracer une importante zone de forte contrainte ductile ayant jusquâĂ cinq kilomĂštres de largeur sur une distance de 70 kilomĂštres en diagonale Ă travers le terrane avalonien de Caledonia, dans le Sud du Nouveau-Brunswick. Une Ă©tude de la partie nord-est de cette zone Ă partir du secteur du mont Prosser, dans le nord-ouest, jusquâau secteur de la riviĂšre Pointe Wolfe, Ă lâouest du parc national du Canada Fundy, rĂ©vĂšle que le groupe dâenviron 630 Ă 620 Ma de la riviĂšre Broad, les plutons connexes et le groupe de 560 Ă 550 Ma de Coldbrook abritent des Ă©lĂ©ments structuraux similaires, apparentĂ©s Ă des dĂ©formations passĂ©es largement partagĂ©es. Une certaine partie de ce passĂ© est Ă©galement apparente dans les roches plutoniques de 560 Ă 550 Ma. Une foliation intense (S1) se manifeste parallĂšlement Ă la stratification (S0) et, mĂȘme si cette fabrique est nettement composite (S0-1) dans le groupe de la riviĂšre Broad, elle est trĂšs hĂ©tĂ©rogĂšne dans le groupe plus rĂ©cent de Coldbrook, oĂč les enclaves de faible contrainte sont rĂ©pandues. On nâa observĂ© aucun pli dâune production F1 et aucune inversion du regard ni de la vergence nâest apparente. Une linĂ©ation minĂ©rale (L1m), dĂ©finie par des agrĂ©gats de biotite, est localement bien visible. Les roches plutoniques possĂšdent des fabriques qui se sont constituĂ©es pendant et peu aprĂšs la cristallisation, notamment une foliation (S1) produisant du gneiss oeillĂ© avec L-tectonite (L1m) en Ă©vidence. S1 Ă lâintĂ©rieur des roches plutoniques comporte en outre une schistositĂ© associĂ©e Ă la croissance de mica blanc et Ă la dĂ©composition de feldspath. La gĂ©omĂ©trie permet de supposer que S1 dans les granites est apparentĂ©e Ă S0-1 dans les roches supracrustales et que la linĂ©ation minĂ©rale (L1m) dans les deux unitĂ©s partage une orientation commune. S1 et S0-1 sont crĂ©nelĂ©s par une seconde schistositĂ© (S2) prononcĂ©e, de plan axial par rapport aux plis (F2), dont lâexpression Ă grande Ă©chelle est une synforme asymĂ©trique renfermant une ceinture de roches du groupe de Coldbrook. Les indicateurs cinĂ©matiques des structures F2 permettent de supposer un mouvement gĂ©nĂ©ral du sommet vers le sud-est le long des chevauchements qui empilent les unitĂ©s du groupe de la riviĂšre Broad, du groupe de Coldbrook et des roches plutoniques. Le dĂ©veloppement de la fabrique dans les roches plutoniques plus ĂągĂ©es suppose une exhumation passĂ©e ayant commencĂ© dans des conditions trĂšs chaudes et anhydres pendant et peu aprĂšs la cristallisation, vers 620 Ma, suivie par une hydratation pendant la rĂ©trogression au moment oĂč les roches plutoniques se sont tectoniquement mises en place Ă lâintĂ©rieur de cet Ă©peron crustal. LâĂąge des Ă©vĂ©nements tectoniques tardifs nâest pas encore bien circonscrit, mais ils pourraient remonter au CarbonifĂšre. [Traduit par la redaction
New Cryogenian, Neoproterozoic, and middle Paleozoic UâPb zircon ages from the Caledonia terrane, southern New Brunswick, Canada: better constrained but more complex volcanic stratigraphy
New UâPb zircon ages from volcanic, plutonic, and sedimentary units in the Avalonian Caledonia terrane of southern New Brunswick provide better timing constraints in this geologically complex area. Previous ca. 620 Ma ages from the Broad River Group are now corroborated by additional dates from felsic tuff in the Gordon Falls Formation and rhyolite in the former Fairfield (now East Branch Black River) Formation of 620 ± 5 Ma and 622 ± 1.9 Ma, respectively. Combined with ages ranging from ca. 625 Ma to 615 Ma from crosscutting plutons, the data suggest that the minimum age of the Broad River Group is about 615 Ma. A quartzfeldspar porphyry dyke in mafic volcanic rocks of the previously undated Long Beach Formation yielded an igneous crystallization age of 685 ± 10 Ma, the oldest unit yet dated in the Caledonia terrane but similar in age to porphyry in the Stirling belt in the Avalonian Mira terrane of Nova Scotia. The age of the Coldbrook Group was constrained previously by UâPb (zircon) ages of volcanic rocks between 560 and 550 Ma as well as by similar ages from comagmatic plutons. Five additional samples from both volcanic and plutonic units lie in the same range of 560â550 Ma, including errors, demonstrating that the Coldbrook Group and related plutons formed in less than 10 million years. Such a large volume of mainly felsic magma erupted and emplaced in a short time span suggests a âsupereruption/supervolcanoâ environment such as the late Cenozoic southwestern USA but not yet recognized at ca. 560â550 Ma elsewhere in Avalonia. Two units yielded Paleozoic ages: felsite of the Bloomsbury Mountain Formation with a zircon population at 427 ± 9 Ma, indicating a Silurian maximum emplacement age, and dacite of the Grassy Lake Formation with several zircon grains at 382.8 ± 8.3 Ma, indicating a maximum age of middle Devonian, the first rocks of this age to be identified in the Caledonia terrane
The uses and gratifications of using Facebook music listening applications
Despite rapid adoption of social media as a means of music listening, little is known about usersâ motivations. This study applies the uses and gratifications approach to usersâ motivations for using music listening applications on Facebook. Participants completed an online survey, and 153 out of 576 respondents indicated that they used a Facebook music listening application. A principal axis factor analysis identified three different motivations for this usage, namely entertainment, communication, and habitual diversion gratifications. The entertainment and communication gratifications replicate those found in prior uses and gratifications research concerning other social networking features, illustrating the strong similarity between uses of music and social media. However, the habitual diversion gratification may serve to distinguish listening applications from other features. Identifying and explaining these factors is relevant to social media users, musicians and application designers, as they explain what motivates a means of music listening that is gaining prominence
Do shorter lengths of stay increase readmissions after total joint replacements?
BackgroundEnhanced recovery after surgery protocols for total joint replacements (TJRs) emphasize early discharge, yet the impact on readmissions is not well documented. We evaluate the impact of a one-day length of stay (LOS) discharge protocol on readmissions.MethodsWe conducted a retrospective review of all primary TJRs (hip and knee) from April 2014 to March 2015. Patients who had adequate support to be discharged home were categorized into 2 groups, 1-day (n = 174) vs 2-day (n = 285) LOS groups. Patients discharged to rehabilitation were excluded (n = 196).ResultsPatients in the 1 day group were more likely to be younger (61.7 vs 64.8 years, P < .001), be male (56.3% vs 40.4%, P = .001), and have a lower body mass index (30.0 vs 31.4 kg/m2, P = .012). One-day LOS patients had shorter surgical times (79.7 vs 85.6 minutes, P = .001) and more likely had spinal anesthesia (46.0% vs 31.2%, P = .001). The overall 30-day all-cause (2.3% vs 2.5%, P = .591) and 90-day wound-related (1.1% vs 1.1%, P = .617) readmission rates were equivalent between groups.ConclusionsEarly discharge does not increase readmissions and may help attenuate costs associated with TJRs. Further refinement of protocols may allow for more patients to be safely discharged on postoperative day 1
Haloe Antarctic observations in the spring of 1991
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95167/1/grl6630.pd
REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting
Background
The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out.
Methods
A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients.
Results
Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items.
Conclusion
REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure
Sensitivity of Mitochondrial Transcription and Resistance of RNA Polymerase II Dependent Nuclear Transcription to Antiviral Ribonucleosides
Ribonucleoside analogues have potential utility as anti-viral, -parasitic, -bacterial and -cancer agents. However, their clinical applications have been limited by off target effects. Development of antiviral ribonucleosides for treatment of hepatitis C virus (HCV) infection has been hampered by appearance of toxicity during clinical trials that evaded detection during preclinical studies. It is well established that the human mitochondrial DNA polymerase is an off target for deoxyribonucleoside reverse transcriptase inhibitors. Here we test the hypothesis that triphosphorylated metabolites of therapeutic ribonucleoside analogues are substrates for cellular RNA polymerases. We have used ribonucleoside analogues with activity against HCV as model compounds for therapeutic ribonucleosides. We have included ribonucleoside analogues containing 2âČ-C-methyl, 4âČ-methyl and 4âČ-azido substituents that are non-obligate chain terminators of the HCV RNA polymerase. We show that all of the anti-HCV ribonucleoside analogues are substrates for human mitochondrial RNA polymerase (POLRMT) and eukaryotic core RNA polymerase II (Pol II) in vitro. Unexpectedly, analogues containing 2âČ-C-methyl, 4âČ-methyl and 4âČ-azido substituents were inhibitors of POLRMT and Pol II. Importantly, the proofreading activity of TFIIS was capable of excising these analogues from Pol II transcripts. Evaluation of transcription in cells confirmed sensitivity of POLRMT to antiviral ribonucleosides, while Pol II remained predominantly refractory. We introduce a parameter termed the mitovir (mitochondrial dysfunction caused by antiviral ribonucleoside) score that can be readily obtained during preclinical studies that quantifies the mitochondrial toxicity potential of compounds. We suggest the possibility that patients exhibiting adverse effects during clinical trials may be more susceptible to damage by nucleoside analogs because of defects in mitochondrial or nuclear transcription. The paradigm reported here should facilitate development of ribonucleosides with a lower potential for toxicity
- âŠ