49 research outputs found
The Timing of Strike-Slip Deformation Along the StorstrĂžmmen Shear Zone, Greenland Caledonides: UâPb Zircon and Titanite Geochronology
The StorstrĂžmmen shear zone (SSZ) in the Greenland Caledonides is widely interpreted to have formed in a transpressional regime during sinistral, oblique collision between Baltica and Laurentia in the Silurian to Devonian. New mapping of the SSZ at Sanddal documents a 100 m thick, greenschistfacies mylonite zone cutting the eclogite to amphibolite-facies gneiss complex. We present UâPb ion probe geochronology on zircon and titanite from a variety of lithologies that shows the SSZ was active from late Devonian to the Carboniferous (at least until 350 Ma). The age of thrusting in the foreland is not well known, but must be younger than the age of eclogite-facies metamorphism at ~400 Ma. It is, therefore, possible that contraction is the same age as strike-slip motion, and that transpression is a viable model. The timing of the SSZ is synchronous with dextral strike-slip displacement on the Germania Land deformation zone. Simultaneous displacement on sinistral and dextral, conjugate shear zones suggests that the SSZ is part of a strikeslip fault system that led to lateral escape of material northward (present day coordinates) during the waning stages of plate convergence between Laurentia and Baltica.SOMMAIRELa zone de cisaillement de StorstrĂžmmen (SSZ) dans les CalĂ©donides du Groenland est gĂ©nĂ©ralement comprise comme ayant Ă©tĂ© formĂ©e durant un rĂ©gime de transpression sĂ©nestre lors de la collision oblique entre Baltica et Laurentie, du Silurien au DĂ©vonien. Une nouvelle cartographie de la SSZ Ă Sanddal dĂ©crit une zone de 100 m dâĂ©paisseur de mylonite au faciĂšs des schistes verts qui recoupe un complexe de gneiss au faciĂšs Ă©clogite Ă amphibolite. Notre analyse gĂ©ochronologique par sonde ionique U-Pb sur zircon et titanite sur diverses lithologies, montre que la SSZ a Ă©tĂ© active de la fin du DĂ©vonien jusquâau CarbonifĂšre (au moins jusquâĂ 350 Ma). LâĂąge du chevauchement dans lâavant-pays nâest pas bien connue, mais il doit ĂȘtre plus jeune que le mĂ©tamorphisme au faciĂšs dâĂ©clogite Ă ~400 Ma. Il est donc possible que la contraction soit du mĂȘme Ăąge que le mouvement de coulissage, et que la transpression soit un modĂšle viable. La chronologie de la SSZ est synchrone au mouvement de coulissage dextre de la zone de dĂ©formation de Germania Land. Les dĂ©placements simultanĂ©s, sĂ©nestre et dextre, sur des zones de cisaillement conjuguĂ©es permettent de penser que la SSZ fait partie dâun systĂšme de dĂ©crochement qui a engendrĂ© une Ă©jection latĂ©rale de matĂ©riau vers le nord (selon les coordonnĂ©es actuelles) durant les stades de convergence des plaques Laurentie et Baltica
Foundations of Translational Ecology
Ecologists who specialize in translational ecology (TE) seek to link ecological knowledge to decision making by integrating ecological science with the full complement of social dimensions that underlie today\u27s complex environmental issues. TE is motivated by a search for outcomes that directly serve the needs of natural resource managers and decision makers. This objective distinguishes it from both basic and applied ecological research and, as a practice, it deliberately extends research beyond theory or opportunistic applications. TE is uniquely positioned to address complex issues through interdisciplinary team approaches and integrated scientistâpractitioner partnerships. The creativity and context-specific knowledge of resource managers, practitioners, and decision makers inform and enrich the scientific process and help shape use-driven, actionable science. Moreover, addressing research questions that arise from on-the-ground management issues â as opposed to the top-down or expert-oriented perspectives of traditional science â can foster the high levels of trust and commitment that are critical for long-term, sustained engagement between partners
Ovarian cancer screening and mortality in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a randomised controlled trial
Background Ovarian cancer has a poor prognosis, with just 40% of patients surviving 5 years. We designed this trial
to establish the eff ect of early detection by screening on ovarian cancer mortality.
Methods In this randomised controlled trial, we recruited postmenopausal women aged 50â74 years from 13 centres in
National Health Service Trusts in England, Wales, and Northern Ireland. Exclusion criteria were previous bilateral oophorectomy or ovarian malignancy, increased risk of familial ovarian cancer, and active non-ovarian malignancy. The trial management system confirmed eligibility and randomly allocated participants in blocks of 32 using computergenerated random numbers to annual multimodal screening (MMS) with serum CA125 interpreted with use of the risk of ovarian cancer algorithm, annual transvaginal ultrasound screening (USS), or no screening, in a 1:1:2 ratio. The primary outcome was death due to ovarian cancer by Dec 31, 2014, comparing MMS and USS separately with no screening, ascertained by an outcomes committee masked to randomisation group. All analyses were by modified intention to screen, excluding the small number of women we discovered after randomisation to have a bilateral oophorectomy, have ovarian cancer, or had exited the registry before recruitment. Investigators and participants were aware of screening type. This trial is registered with ClinicalTrials.gov, number NCT00058032.
Findings Between June 1, 2001, and Oct 21, 2005, we randomly allocated 202 638 women: 50 640 (25·0%) to MMS,
50 639 (25·0%) to USS, and 101 359 (50·0%) to no screening. 202 546 (>99·9%) women were eligible for analysis: 50 624 (>99·9%) women in the MMS group, 50 623 (>99·9%) in the USS group, and 101 299 (>99·9%) in the no
screening group. Screening ended on Dec 31, 2011, and included 345 570 MMS and 327 775 USS annual screening
episodes. At a median follow-up of 11·1 years (IQR 10·0â12·0), we diagnosed ovarian cancer in 1282 (0·6%) women:
338 (0·7%) in the MMS group, 314 (0·6%) in the USS group, and 630 (0·6%) in the no screening group. Of these women, 148 (0·29%) women in the MMS group, 154 (0·30%) in the USS group, and 347 (0·34%) in the no screening group had died of ovarian cancer. The primary analysis using a Cox proportional hazards model gave a mortality reduction over years 0â14 of 15% (95% CI â3 to 30; p=0·10) with MMS and 11% (â7 to 27; p=0·21) with USS. The Royston-Parmar fl exible parametric model showed that in the MMS group, this mortality eff ect was made up of 8% (â20 to 31) in years 0â7 and 23% (1â46) in years 7â14, and in the USS group, of 2% (â27 to 26) in years 0â7 and 21% (â2 to 42) in years 7â14. A prespecified analysis of death from ovarian cancer of MMS versus no screening with exclusion of prevalent cases showed significantly diff erent death rates (p=0·021), with an overall average mortality reduction of 20% (â2 to 40) and a reduction of 8% (â27 to 43) in years 0â7 and 28% (â3 to 49) in years 7â14 in favour of MMS.
Interpretation Although the mortality reduction was not signifi cant in the primary analysis, we noted a signifi cant mortality reduction with MMS when prevalent cases were excluded. We noted encouraging evidence of a mortality reduction in years 7â14, but further follow-up is needed before firm conclusions can be reached on the efficacy and cost-eff ectiveness of ovarian cancer screening
Priorities for synthesis research in ecology and environmental science
ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD
Priorities for synthesis research in ecology and environmental science
ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD
Deep Phenotyping of Post-infectious Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Post-infectious myalgic encephalomyelitis/chronic fatigue syndrome (PI-ME/CFS) is a disabling disorder, yet the clinical phenotype is poorly defined, the pathophysiology is unknown, and no disease-modifying treatments are available. We used rigorous criteria to recruit PI-ME/CFS participants with matched controls to conduct deep phenotyping. Among the many physical and cognitive complaints, one defining feature of PI-ME/CFS was an alteration of effort preference, rather than physical or central fatigue, due to dysfunction of integrative brain regions potentially associated with central catechol pathway dysregulation, with consequences on autonomic functioning and physical conditioning. Immune profiling suggested chronic antigenic stimulation with increase in naĂŻve and decrease in switched memory B-cells. Alterations in gene expression profiles of peripheral blood mononuclear cells and metabolic pathways were consistent with cellular phenotypic studies and demonstrated differences according to sex. Together these clinical abnormalities and biomarker differences provide unique insight into the underlying pathophysiology of PI-ME/CFS, which may guide future intervention
Feasibility and pilot efficacy of a brief smoking cessation intervention delivered by vascular surgeons in the Vascular Physician Offer and Report (VAPOR) Trial
BACKGROUND: This study determined the feasibility and potential efficacy of an evidence-based standardized smoking cessation intervention delivered by vascular surgeons to smokers with peripheral arterial disease. METHODS: We performed a cluster-randomized trial of current adult smokers referred to eight vascular surgery practices from September 1, 2014, to July 31, 2015. A three-component smoking cessation intervention (physician advice, nicotine replacement therapy, and telephone-based quitline referral) was compared with usual care. The primary outcome was smoking cessation for 7 days, assessed 3 months after the intervention. Secondary outcomes were patients\u27 nicotine dependence and health expectancies of smoking assessed using Patient Reported Outcomes Measurement Information System (PROMIS; RAND Corporation, Santa Monica, Calif). RESULTS: We enrolled 156 patients (65 in four intervention practices, 91 in four control practices), and 141 (90.3%) completed follow-up. Patients in the intervention and control practices were similar in age (mean, 61 years), sex (68% male), cigarettes per day (mean, 14), and prior quit attempts (77%). All three components of the intervention were delivered to 75% of patients in intervention practices vs to 7% of patients at control practices (P \u3c .001). At 3 months, 23 of 57 patients (40.3%) in the intervention group quit smoking (23 of 56 patients quit who completed follow-up, plus 1 death included in the analysis in the denominator as a smoker), and 26 of 84 patients (30.9%) In the control group quit smoking (26 patients of 84 who completed follow-up, including 2 deaths included in the denominator as smokers). This difference (40.3% quit rate in intervention, 31% quit rate in control; P = .250) was not statistically significant in crude analyses (P = .250) or analyses adjusted for clustering (P = .470). Multivariable analysis showed factors associated with smoking cessation were receipt of physician advice (odds ratio for cessation, 1.96; 95% confidence interval, 1.28-3.02; P \u3c .002) and nicotine replacement therapy (odds ratio, 1.92; 95% confidence interval, 1.43-2.56; P \u3c .001). CONCLUSIONS: Implementation of a brief, surgeon-delivered smoking cessation intervention is feasible for patients with peripheral arterial disease. A larger trial will be necessary to determine whether this is effective for smoking cessation
Feasibility and pilot efficacy of a brief smoking cessation intervention delivered by vascular surgeons in the Vascular Physician Offer and Report (VAPOR) Trial
BACKGROUND: This study determined the feasibility and potential efficacy of an evidence-based standardized smoking cessation intervention delivered by vascular surgeons to smokers with peripheral arterial disease.
METHODS: We performed a cluster-randomized trial of current adult smokers referred to eight vascular surgery practices from September 1, 2014, to July 31, 2015. A three-component smoking cessation intervention (physician advice, nicotine replacement therapy, and telephone-based quitline referral) was compared with usual care. The primary outcome was smoking cessation for 7 days, assessed 3 months after the intervention. Secondary outcomes were patients\u27 nicotine dependence and health expectancies of smoking assessed using Patient Reported Outcomes Measurement Information System (PROMIS; RAND Corporation, Santa Monica, Calif).
RESULTS: We enrolled 156 patients (65 in four intervention practices, 91 in four control practices), and 141 (90.3%) completed follow-up. Patients in the intervention and control practices were similar in age (mean, 61 years), sex (68% male), cigarettes per day (mean, 14), and prior quit attempts (77%). All three components of the intervention were delivered to 75% of patients in intervention practices vs to 7% of patients at control practices (P \u3c .001). At 3 months, 23 of 57 patients (40.3%) in the intervention group quit smoking (23 of 56 patients quit who completed follow-up, plus 1 death included in the analysis in the denominator as a smoker), and 26 of 84 patients (30.9%) In the control group quit smoking (26 patients of 84 who completed follow-up, including 2 deaths included in the denominator as smokers). This difference (40.3% quit rate in intervention, 31% quit rate in control; P = .250) was not statistically significant in crude analyses (P = .250) or analyses adjusted for clustering (P = .470). Multivariable analysis showed factors associated with smoking cessation were receipt of physician advice (odds ratio for cessation, 1.96; 95% confidence interval, 1.28-3.02; P \u3c .002) and nicotine replacement therapy (odds ratio, 1.92; 95% confidence interval, 1.43-2.56; P \u3c .001).
CONCLUSIONS: Implementation of a brief, surgeon-delivered smoking cessation intervention is feasible for patients with peripheral arterial disease. A larger trial will be necessary to determine whether this is effective for smoking cessation
Regional Study of No-Till Impacts on Near-Surface Aggregate Properties that Influence Soil Erodibility
The extent to which tillage systems modify the near-surface soil aggregate properties aff ecting soilâs susceptibility to erosion by water and wind is not well understood. We hypothesized that an increase in soil organic carbon (SOC) content with conservation tillage systems, particularly no-till (NT), may improve near-surface soil aggregate properties that infl uence soil erodibility. This regional study assessed changes in aggregate resistance to raindrops, dry aggregate wettability, and dry aggregate stability as well as their relationships with changes in SOC content. Four long-term (\u3e19 yr) tillage systems including moldboard plow (MP), conventional till (CT), reduced till (RT), and NT were chosen across the central Great Plains at Hays and Tribune, KS, Akron, CO, and Sidney, NE. The kinetic energy (KE) of raindrops required to disintegrate 4.75- to 8-mm aggregates from NT soils equilibrated at â0.03 and â155 MPa matric potential was between two and seven times greater than that required for MP and CT soils in the 0- to 2-cm depth in all soils. At the same depth, the water drop penetration time (WDPT) in aggregates from NT soils was four times greater at Akron and Hays and seven times greater at Sidney and Tribune compared with that in plowed soils. Aggregates from NT soils were more stable under rain and less wettable than those from plowed soils particularly in the surface 0 to 5 cm, but RT had lesser beneficial effects than NT management. The SOC content increased with NT over MP and CT and explained 35% of the variability across soils in aggregate wettability and 28% of the variability in resistance to raindrops in the 0- to 2-cm depth. Aggregate wettability explained 47% of the variability across soils in KE of raindrops required for the disintegration of aggregates. No-till management did not affect dry aggregate-size distribution and stability except at Akron where mean weight diameter (MWD) in RT and NT was 50% lower than in MP management in the 0- to 2-cm depth. Aggregates in MP and CT soils were either stronger or equally strong when dry but less stable when wet than in NT soils. Overall, NT farming enhanced near-surface aggregate properties affecting erosion by water but had small or no effects on dry aggregate stability