213 research outputs found
Internal geometry of the central Sesia Zone (Aosta Valley, Italy): HP tectonic assembly of continental slices
Detailed field mapping reveals that the Sesia Zone is subdivided into two complexes with the Barmet Shear Zone (BSZ) outlining the tectonic contact between them. This greenschist-facies contact reflects a metamorphic gap between the Internal Complex (eclogite facies, eclogitic micaschists dominant) and the External Complex (epidote blueschist facies). The BSZ comprises a wedge shape area in which fragments and slices of orthogneiss and paragneiss are wrapped by siliceous dolomite marbles displaying a mylonitic foliation. Conspicuous cornieules and high pressure breccias occur along this contact. We propose that the eclogite facies Internal Complex is subdivided into three basement units, called sheets, delimited by discontinuous metasedimentary trails of probable Mesozoic age. Thin monocyclic bands thus separate kilometre scale polycyclic sheets. The External Complex comprises three epidote blueschist facies sheets of comparable size, which are separated by lenses retaining a pre-Alpine high temperature imprint. These weakly overprinted fragments (parts of the classically termed 2DK zone) are aligned along greenschist facies shear zones that separate the gneissic sheets. The BSZ, with a wedge rich in meta-sediments, chiefly siliceous dolomite marbles, is a key element in which fragmentation and reworking of materials from the internal and external complexes are evident. A carbonate breccia occurs in this shear zone, with clasts displaying a HP foliation randomly oriented in a ductile carbonate matrix. Siliceous dolomite marbles appear to have acted as lubricants to accommodate deformation related to the juxtaposition of the two basement complexes during exhumation. We propose a model of the Sesia Zone, with the BSZ as the thrust responsible for the juxtaposition of eclogite facies rocks of the Internal Complex on top of epidote blueschist facies rocks of the External Complex. The two complexes were already assembled when this shear zone became active. The entire stack was finally rotated (40\u201360\ub0) during the Vanzone Phase
Exploiting the Gal4/UAS System as Plant Orthogonal Molecular Toolbox to Control Reporter Expression in Arabidopsis Protoplasts
The ability of protein domains to fold independently from the rest of the polypeptide is the principle governing the generation of fusion proteins with customized functions. A clear example is the split transcription factor system based on the yeast GAL4 protein and its cognate UAS enhancer. The rare occurrence of the UAS element in the transcriptionally sensitive regions of the Arabidopsis genome makes this transcription factor an ideal orthogonal platform to control reporter induction. Moreover, heterodimeric transcriptional complexes can be generated by exploiting posttranslational modifications hampering or promoting the interaction between GAL4-fused transcriptional partners, whenever this leads to the reconstitution of a fully functional GAL4 factor. The assembly of multiple engineered proteins into a synthetic transcriptional complex requires preliminary testing, before its components can be stably introduced into the plant genome. Mesophyll protoplast transformation represents a fast and reliable technique to test and optimize synthetic regulatory modules. Remarkable properties are the possibility to transform different combinations of plasmids (co-transformation) and the physiological resemblance of these isolated cells with the original tissue. Here we describe an extensive protocol to produce and exploit Arabidopsis mesophyll protoplasts to investigate the transcriptional output of GAL4/UAS-based complexes that are sensitive to posttranslational protein modifications
Fresh, pseudotachylyte-bearing mantle peridotites from the lawsonite eclogite-facies san petrone unit, alpine corsica
Mantle peridotites exhumed in mountain belts provide important insights on the composition and evolution of the upper mantle, and additionally inform on metamorphic, geochemical, and tectonic processes-including seismic activity-at convergent margins. In this contribution, we present field, microstruc-tural, and mineralogical data of fresh, pseudotachylyte-bearing mantle peridotites from the lawsonite eclogite-facies San Petrone unit, Alpine Corsica, France. The present case study represents the first example of subducted fresh peridotite associated with fresh lawsonite eclogite-facies assemblages. Two bodies of fresh peridotite are embedded in fully serpentinized ultramafic rocks forming the substratum of a subducted ocean-continent transition of the Piemonte-Liguria Basin. Clinopyroxene and spinel mineral chemistry indicates that the investigated peridotite samples were part of a refertilized mantle and, therefore, the San Petrone unit likely belonged to the more distal part of the ocean-continent transition. Because small bodies of fresh peridotite embedded in fully serpentinized rocks can hardly be identified by means of geophysical investigations, this finding suggests that small, yet disseminated bodies of fresh mantle peridotite can potentially be more abundant than previously supposed at ocean-continent transition and, potentially, at mid-ocean ridges and in subduction zones. The preservation of fresh mantle peridotite bodies in subducting slabs is also discussed with respect to its potential implications on intermediate depth seismicity and geochemical cycling-including production of natural energy sources-from rifting to subduction
Constraints on upper crustal fluid circulation and seismogenesis from in-situ outcrop quantification of complex fault zone permeability
: The permeability of fault zones plays a significant role on the distribution of georesources and on seismogenesis in the brittle upper crust, where both natural and induced seismicity are often associated with fluid migration and overpressure. Detailed models of the permeability structure of fault zones are thus necessary to refine our understanding of natural fluid pathways and of the mechanisms leading to fluid compartmentalization and possible overpressure in the crust. Fault zones commonly contain complex internal architectures defined by the spatial juxtaposition of "brittle structural facies" (BSF), which progressively and continuously form and evolve during faulting and deformation. We present the first systematic in-situ outcrop permeability measurements from a range of BSFs from two architecturally complex fault zones in the Northern Apennines (Italy). A stark spatial heterogeneity of the present-day permeability (up to four orders of magnitude) even for tightly juxtaposed BSFs belonging to the same fault emerges as a key structural and hydraulic feature. Insights from this study allow us to better understand how complex fault architectures steer the 3D hydraulic structure of the brittle upper crust. Fault hydraulic properties, which may change through space but also in time during an orogenesis and/or individual seismic cycles, in turn steer the development of overpressured volumes, where fluid-induced seismogenesis may localize
Constraints on upper crustal fluid circulation and seismogenesis from in-situ outcrop quantification of complex fault zone permeability
The permeability of fault zones plays a significant role on the distribution of georesources and on seismogenesis in the brittle upper crust, where both natural and induced seismicity are often associated with fluid migration and overpressure. Detailed models of the permeability structure of fault zones are thus necessary to refine our understanding of natural fluid pathways and of the mechanisms leading to fluid compartmentalization and possible overpressure in the crust. Fault zones commonly contain complex internal architectures defined by the spatial juxtaposition of "brittle structural facies" (BSF), which progressively and continuously form and evolve during faulting and deformation. We present the first systematic in-situ outcrop permeability measurements from a range of BSFs from two architecturally complex fault zones in the Northern Apennines (Italy). A stark spatial heterogeneity of the present-day permeability (up to four orders of magnitude) even for tightly juxtaposed BSFs belonging to the same fault emerges as a key structural and hydraulic feature. Insights from this study allow us to better understand how complex fault architectures steer the 3D hydraulic structure of the brittle upper crust. Fault hydraulic properties, which may change through space but also in time during an orogenesis and/or individual seismic cycles, in turn steer the development of overpressured volumes, where fluid-induced seismogenesis may localize
Predictive relation for the α-relaxation time of a coarse-grained polymer melt under steady shear
We examine the influence of steady shear on structural relaxation in a simulated coarse-grained unentangled polymer melt over a wide range of temperature and shear rates. Shear is found to progressively suppress the α-relaxation process observed in the intermediate scattering function, leading ultimately to a purely inertially dominated β-relaxation at high shear rates, a trend similar to increasing temperature. On the basis of a scaling argument emphasizing dynamic heterogeneity in cooled liquids and its alteration under material deformation, we deduce and validate a parameter-free scaling relation for both the structural relaxation time τα from the intermediate scattering function and the “stretching exponent” β quantifying the extent of dynamic heterogeneity over the entire range of temperatures and shear rates that we can simulate
Evaluation of NSW Community-based Mental Health Programs: Community Living Supports and Housing and Accommodation Support Initiative. CLS-HASI Evaluation Report
The Community Living Supports (CLS) and Housing and Accommodation Support Initiative (HASI) are community-based programs that support people with severe mental illness to live and participate in the community, the way that they want to. The programs offer psychosocial support, tenancy support and, where appropriate, clinical mental health services. Many consumers are also supported to access secure housing. CLS-HASI are statewide programs funded by the NSW Ministry of Health (Ministry) and delivered locally through partnerships between local health district (LHD) mental health services and specialist mental health Community Managed Organisations (CMOs). The programs also have a strong partnership with the NSW Department of Communities and Justice (DCJ) and community housing providers for social housing. The Ministry commissioned the Social Policy Research Centre (SPRC) to evaluate the CLS-HASI programs. The evaluation involved two rounds of qualitative interviews and focus groups, as well as the analysis of quantitative program data and statewide outcomes data about consumers. It ran from November 2017 to January 2020. CLS-HASI supported 5,533 consumers in the study period from 2015 to 2019. Most consumers were in the programs for only part of this period. The average time in CLS-HASI was 10.7 months. Overall, the evaluation shows that CLS-HASI is generally working well, achieving its goals and is cost effective. At a broad summary level: • Consumers liked the programs, and most experienced positive outcomes – overall the programs improved wellbeing, helped people better manage their mental health, enhanced aspects of consumers’ physical health and increased opportunities for social inclusion. • Consumer contact with community mental health services decreased by 10% in the first year in CLS-HASI and was 63.7% less if they remained in the programs for more than one year. • Hospital admissions due to mental health decreased by 74% following program entry, and the average length of stay decreased by 74.8% over two years. This improvement was sustained after consumers exited the programs. • Consumers with a new charge in the criminal justice system and with community corrections orders dropped to almost zero in the year after program entry
An inverse modeling approach to obtain P-T conditions of metamorphic stages involving garnet growth and resorption
This contribution presents an approach and a computer program (GRTMOD) for numerical simulation of garnet evolution based on compositions of successive growth zones in natural samples. For each garnet growth stage, a new local effective bulk composition is optimized, allowing for resorption and/or fractionation of previously crystallized garnet. The successive minimizations are performed using the Nelder-Mead algorithm; a heuristic search method. An automated strategy including two optimization stages and one refinement stage is described and tested. This program is used to calculate pressure-temperature (P-T) conditions of crystal growth as archived in garnet from the Sesia Zone (Western Alps). The compositional variability of successive growth zones is characterized using standardized X-ray maps and the program XMapTools. The model suggests that Permian garnet cores crystallized under granulite-facies conditions at T>800 °C and P = 6 kbar. During Alpine times, a first garnet rim grew at eclogite-facies conditions (650 °C, 16 kbar) at the expense of the garnet core. A second rim was added at lower P (∼11 kbar) and 630 °C. In total, garnet resorption is modeled to amount to ∼9 vol% during the Alpine evolution; this value is supported by our observations in X-ray compositional maps
Social Participation of People with Chronic Mental Health Needs: Building Horizontal and Vertical Forms of Social Capital
Social participation is positively related to mental health recovery and wellbeing, yet people with mental health problems are often socially isolated. This article investigates how social participation was incorporated into an Australian-integrated program that aimed to improve the wellbeing of people with chronic mental health needs. The data are from a longitudinal evaluation of the integrated program, including data linkage (5533 participants) and interviews (111). The paper uses concepts from the network perspective of social capital (bonding, bridging, linking, horizontal, and vertical) as lenses to re-examine the evaluation's findings about the consumers' social participation in life areas (social, leisure, and productive) facilitated by the program. This social capital perspective offers a lens to examine the breadth and intensity of participation experienced by the consumers taking part in the support program. The article adds to the literature about how service providers can improve social participation and therefore consumers' opportunities for recovery and wellbeing. The analyses found that the support increased people's social interaction and their capacity in the community. Their social interaction was mostly with other people in the service. Often their interactions in the community were only transactional. Few consumers participated in activities in productive life areas, and few of the activities promoted vertical social capital in social networks outside the service. The implications are that service providers need greater attention on facilitating a variety of social participation activities that can extend mental health consumers' horizontal and vertical social capital and so further contribute to their current and future recovery and wellbeing
Forming and preserving aragonite in shear zones: First report of blueschist facies metamorphism in the Jabal Akhdar Dome, Oman Mountains
We report the first occurrence of high-pressure metamorphic aragonite in Precambrian
carbonates of the Jabal Akhdar Dome in the Oman Mountains (northern Oman). We propose
a model for both its formation at blueschist facies conditions and its subsequent preservation
to the surface within the tectonic framework of the Late Cretaceous obduction of
the Semail Ophiolite. Aragonite formed at temperature ∼350 °C and pressure ≥0.9 GPa and
is preserved within mylonitic shear zones and in stretched-fiber dilational veins where the
necessary conditions for its formation and preservation, such as plastic strain accommodation,
fluid-enhanced mineralogical reactions, and an anisotropic permeability structure, were
preferentially met with respect to the surrounding rock. High-strain structural domains are
ideal sites to look for and study prograde and retrograde high-pressure metamorphic histories
in deeply subducted and exhumed terrains
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