57 research outputs found
Two-stage exhumation of subducted Saxothuringian continental crust records underplating in the subduction channel and collisional forced folding (KrkonoĆĄe-Jizera Mts., Bohemian Massif)
Source:http://dx.doi.org/10.1016/j.jsg.2016.06.008The KrkonoĆĄe-Jizera Massif in the northern part of the Variscan Bohemian Massif provides insight into the exhumation mechanisms for subducted continental crust. The studied region exposes a relatively large portion of a flat-lying subduction-related complex that extends approximately 50 km away from the paleosuture. wide extent of HP-LT metamorphism has been confirmed by new P-T estimates indicating temperatures of 400â450 °C at 14â16 kbar and 450â520 °C at 14â18 kbar for the easternmost and westernmost parts of the studied area, respectively. A detailed study of metamorphic assemblages associated with individual deformation fabrics together with analysis of quartz deformation microstructures and textures allowed characterisation of the observed deformation structures in terms of their subduction-exhumation memory. An integration of the lithostratigraphic, metamorphic and structural data documents a subduction of distal and proximal parts of the Saxothuringian passive margin to high-pressure conditions and their subsequent exhumation during two distinct stages. The initial stage of exhumation has an adiabatic character interpreted as the buoyancy driven return of continental material from the subduction channel resulting in underplating and progressive nappe stacking at the base of the TeplĂĄ-Barrandian upper plate. With the transition from continental subduction to continental collision during later stages of the convergence, the underplated high-pressure rocks were further exhumed due to shortening in the accretionary wedge. This shortening is associated with the formation of large-scale recumbent forced folds extending across the entire studied area
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and â„1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (nâ=â5069) or prospectively (nâ=â5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (â€6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; pâ=â0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Distinct metasomatic events and their relation to a crustal-scaledeformation zone (Gemer-Vepor Contact Zone, CentralWesternCarpathians)
International audienceNumerous talc, magnesite and siderite ore deposits occur in the Central Western Carpathians (Slovakia) along theso-called Gemer-Vepor Contact Zone, which marks the contact between two major blocks of Variscan basement,the Vepor and Gemer units. During the polyphase deformation of Cretaceous age, the Gemer Unit was first thrustover the Vepor Unit. This is well documented by the development of subhorizontal and prograde metamorphic foliationreaching up to amphibolite facies conditions in the Vepor and by the development of subvertical greenschistfacies cleavages in the Gemer Unit. The subsequent exhumation of the Vepor Unit along large-scale detachmentzone is documented by the development of subhorizontal lower grade cleavage in the Vepor Unit. Finally, the ongoingnorthward propagating convergence with the Gemer Unit led to the development of the sinistral transpressionalTrans-Gemer Shear zone. Two types of shear zones with contrasting metasomatic record have been recognized inthe Vepor Unit. Mg-enriched shear zones heterogeneously develop within the Carboniferous granitoids resulting information of Mg-chloriteâmuscoviteâquartz phyllonites as well as Mg-chloriteâkyanite-bearing schists. Comparedto the composition of granitoids, these mylonites-phyllonites are depleted in alkalies and enriched in magnesium,iron and manganese, which is most likely related to the influx of fluids along the shear zones. The equilibriummineral assemblage chlorite, kyanite, muscovite, rutile and quartz corresponds to 420C at 4 kbar. In contrast,the second type of shear zones developed within chloritoid-kyanite schists of the Veporic Permian cover. Theseshear zones display metasomatic alteration characterized by a strong Fe-enrichment resulting in formation of Fechlorite-muscovite-quartz phyllonite. The unusual enrichment in either Mg or Fe suggests either heterogenous fluidcomposition or two separate metasomatic events in the studied area. Indeed, the two types of shear zones are associatedwith two distinct deformation events. The Mg-enriched first type shear zones are associated with progrademetamorphic evolution related to burial of the Vepor Unit whereas the Fe-enriched second type shear zones arerelated to the Vepor exhumation. Therefore, the formation of these metasomatic rocks reflects different stages ofthe polyphase Cretaceous evolution, rather than heterogenous composition of fluids. The sources of metasomaticfluids are discussed in relation to the nearby ore deposits
Inverse ductile thinning via lower crustal flow and fold-induced doming in the West Carpathian Eo-Alpine collisional wedge
International audienceContinental core complexes are generally interpreted to result from extensional doming due to gravity-driven upflow of lower crust. In contrast, the Vepor Dome is characterized by the lack of inverted density profile and relatively cold metamorphic field gradient which precludes an activation of Rayleigh-Taylor instability. Instead, the crustal structure of the Vepor Unit is marked by dense and weak metapelitic lower crust and light and strong granitoid upper crust inherited from Variscan nappe stacking. It is shown that the Cretaceous Eo-Alpine tectonic evolution of the Vepor Dome is controlled by the dynamics of two neighboring mechanically strong continental blocks, i.e., the overthrusting of the suprastructural Gemer Unit from the south and the underthrusting of the Fatric basement from the north. Structural, metamorphic and geochronological data from the Vepor Unit imply two main phases of the convergent process: (1) Lower Cretaceous crustal thickening due to overthrusting and internal deformation of the Gemer Unit together with upper crustal folding in the Vepor Unit led to the progressive development of the orogenic front parallel pressure gradient. The instantaneous response of the lower crustal and low-viscosity metapelites led to an along-strike lower crustal flow accompanied by prograde Barrovian-type metamorphism. (2) As the south vergent underthrusting of the Fatric basement propagated to greater depths during the Upper Cretaceous, the convergent process switched from top driven to bottom driven, and the exhumation of the lower crust occurred via polyharmonic folding. Overall doming of the Vepor Unit induced upper crustal detachment faulting and eastward unroofing of the dome
Chronology of the Saxothuringian subduction in the West Sudetes (Bohemian Massif, Czech Republic and Poland)
Isotopic dating of monazite and garnet from high-pressure metamorphic rocks exposed in the northern part of the
Saxothuringian palaeo-suture in the Bohemian Massif revealed a diachronous metamorphism of various rock types that are now
closely associated within allochthonous units representing the DevonianâCarboniferous subductionâaccretionary complex.
Mafic blueschists of the middle unit yielded a LuâHf garnet age of 363.9 ± 1.3 Ma. The blueschists occur within high-pressure,
garnet-free phyllites. Monazite extracted from this rock type yielded a UâPb isotope dilution thermal ionization mass
spectrometry age of 336.5 ± 0.5 Ma. Garnet-bearing micaschist of the lower unit contains monazite with a UâPb secondary ion
mass spectrometry age of 341 ± 3 Ma, consistent with LuâHf garnetâwhole-rock ages of 344.5 ± 1.3 and 342 ± 7 Ma obtained
from the same rock type. Existing tectonic models of the Bohemian Massif, and particularly of its northern part, assume that the
period of oceanic subduction was terminated at c. 380â375 Ma by the arrival of an attenuated Saxothuringian continental crust,
which was partly subducted and partly relaminated underneath the overriding TeplĂĄâBarrandian Domain. However, our data, as
well as data from mafic high-pressure rocks in the southern part of the Saxothuringian Domain, suggest that the initial collision
was probably caused by the arrival of a smaller crustal block present within the Saxothuringian oceanic domain. After its
subduction and relamination, the oceanic subduction was re-established and terminated by continental subduction and later
collision of the Saxothuringian passive margin at c. 345â335 M
Telematics System dedicated for Provisioning of On-Line Information about Predicted Occupancy of Highway Parking Areas
More and more often occurs problem with the lack of parking places for trucks over 3.5t, which is related to the increase in the intensity of freight transport. Consequently this can lead to very dangerous situations with parking of trucks because drivers do not have information about the occupancy of the nearest parking. The paper presents an intelligent transportation system, which provides information about the predicted occupancy of parking lots to truck drivers. Providing this information leads to optimizing the use of existing parking areas on the highway network and also makes it easier for drivers to deciding on a suitable location for parking, which ultimately contributes to the fluency and safety of traffic
Degradation of ÎČ-Hexachlorocyclohexane by Haloalkane Dehalogenase LinB from Sphingomonas paucimobilis UT26
ÎČ-Hexachlorocyclohexane (ÎČ-HCH) is the most recalcitrant among the α-, ÎČ-, Îł-, and ÎŽ-isomers of HCH and causes serious environmental pollution problems. We demonstrate here that the haloalkane dehalogenase LinB, reported earlier to mediate the second step in the degradation of Îł-HCH in Sphingomonas paucimobilis UT26, metabolizes ÎČ-HCH to produce 2,3,4,5,6-pentachlorocyclohexanol
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