Distributed transpressive continental deformation: The Varto Fault Zone, eastern Turkey

The convergence between the Eurasian and Arabian plates has created a complicated structural setting in the Eastern Turkish high plateau (ETHP), particularly around the Karlıova Triple Junction (KTJ) where the Eurasian, Arabian, and Anatolian plates intersect. This region of interest includes the junction of the North Anatolian Shear Zone (NASZ) and the East Anatolian Shear Zone (EASZ), which forms the northern border of the westwardly extruding Anatolian Scholle and the western boundary of the ETHP, respectively. In this study, we focused on a poorly studied component of the KTJ, the Varto Fault Zone (VFZ), and the adjacent secondary structures, which have complex structural settings. Through integrated analyses of remote sensing and field observations, we identified a widely distributed transpressional zone where the Varto segment of the VFZ forms the most northern boundary. The other segments, namely, the Leylekdağ and Çayçatı segments, are oblique-reverse faults that are significantly defined by uplifted topography along their strikes. The measured 515 and 265 m of cumulative uplifts for Mt. Leylek and Mt. Dodan, respectively, yield a minimum uplift rate of 0.35 mm/a for the last 2.2 Ma. The multi-oriented secondary structures were mostly correlated with “the distributed strike-slip” and “the distributed transpressional” in analogue experiments. The misfits in strike of some of secondary faults between our observations and the experimental results were justified by about 20° to 25° clockwise restoration of all relevant structures that were palaeomagnetically measured to have happened since ~ 2.8 Ma ago. Our detected fault patterns and their true nature are well aligned as being part of a transpressional tectonic setting that supports previously suggested stationary triple junction models.

Parcours scolaires, accès aux études supérieures et mobilité sociale: comparaison entre la France, la Suisse et le Canada

Le présent article examine dans quelle mesure l’organisation des trajectoires scolaires et les parcours conduisant à l’enseignement supérieur favorisent la mobilité sociale ou au contraire la reproduction des inégalités. Nous avons comparé trois pays : la France, la Suisse et le Canada. Les résultats obtenus à partir des données tirées des panels d’enquêtes menées dans ces trois pays permettent d’observer deux situations opposées. Plus l’enseignement supérieur est valorisé au détriment de la formation professionnelle, plus les inégalités d’accès à l’enseignement supérieur ont tendance à s’exacerber. La compétition y est telle que ce sont les jeunes de milieu favorisé qui tirent davantage profit de son expansion. Par contre, lorsque la formation professionnelle est valorisée, les inégalités auraient plutôt tendance à être modérées.

Management of a complication with a fractured zirconia implant abutment in the esthetic zone

Technical complications in implant prosthetic cases represent a major challenge in dentistry. This case report describes minimally invasive management to recover an implant with a fractured remnant of a zirconia abutment, including provisional rehabilitation during a sequential treatment protocol in the esthetic zone. A patient was treated with a screw-retained one-piece implant-supported reconstruction made of a customized zirconia abutment with direct ceramic veneering in the maxillary right central incisor position. During the prosthetic try-in, a fracture in the apical portion of the abutment was evident. The first rescue attempt led to fracture of the retrieval instrument. Immediately, an individualized wired construction was applied to bond the existing fractured reconstruction to the neighboring teeth to maintain the peri-implant mucosal architecture. Because the implant screw canal was blocked, a customized round bur had to be manufactured and was placed in the implant axis with a specific bracket tool from the service set to protect the interior implant threads. Then, the drills of the service set were guided by the newly created access to remove the fractured remnants. The implant screw was retapped and the area rinsed with chlorhexidine solution. All remnants were removed without the need for surgical intervention. Neither the implant connection nor the bone-to-implant interface was damaged. The stepwise treatment approach with the customized round bur combined with the system-specific drills of the service set saved the blocked implant so that the patient could be successfully rehabilitated with a new implant reconstruction.

Immediate implant placement with simultaneous guided bone regeneration in the esthetic zone: 10-year clinical and radiographic outcomes.

AIM To associate the dimension of the facial bone wall with clinical, radiological, and patient-centered outcomes at least 10 years after immediate implant placement with simultaneous guided bone regeneration in a retrospective study. MATERIAL AND METHODS Primary endpoint was the distance from the implant shoulder (IS) to the first bone-to-implant contact (IS-BIC10y ). Secondary endpoints included the facial bone thickness (BT10y ) 2, 4, and 6 mm apical to the IS, and the implant position. At baseline, the horizontal defect width (HDWBL ) from the implant surface to the alveolar wall was recorded. At recall, distance from the IS to the mucosal margin (IS-MM10y ), degree of soft tissue coverage of the mesial and distal aspects of the implants (PISm10y , PISd10y ; Papilla Index), pocket probing depth (PPD10y ), and patient-centered outcomes were determined. Width of the keratinized mucosa (KM), Full-Mouth Plaque and Bleeding Score (FMPS, FMBS) were available for both time points. RESULTS Of the 20 patients who underwent immediate implant placement with simultaneous guided bone regeneration and transmucosal healing, nine males and eight females with a median age of 62 years (42 min, 84 max) were followed up for a median period of 10.5 y (min 10.1 max 11.5). The 10-year implant survival rate was 100%. Multivariate regression analysis revealed a correlation of the IS-BIC10y , controlled for age and gender, with four parameters: HDWBL (P = 0.03), KMBL -10 (P = 0.02), BT10 4 mm (P = 0.01), and BT10 6 mm (P = 0.01). CONCLUSION Within the conditions of the present study, the horizontal defect width was the main indicator for the vertical dimension of the facial bone. The facial bone dimension was further associated with a reduction in the width of the keratinized mucosa and the dimension of the buccal bone.

Constraints on the thermal evolution of the Adriatic margin during Jurassic continental break-up: U–Pb dating of rutile from the Ivrea–Verbano Zone, Italy

The Ivrea–Verbano Zone (IVZ), northern Italy, exposes an attenuated section through the Permian lower crust that records high-temperature metamorphism under lower crustal conditions and a protracted history of extension and exhumation associated partly with the Jurassic opening of the Alpine Tethys ocean. This study presents SHRIMP U–Pb geochronology of rutile from seven granulite facies metapelites from the base of the IVZ, collected from locations spanning ~35 km along the strike of Paleozoic fabrics. Rutile crystallised during Permian high-temperature metamorphism and anatexis, yet all samples give Jurassic rutile U–Pb ages that record cooling through 650–550 °C. Rutile age distributions are dominated by a peak at ~160 Ma, with a subordinate peak at ~175 Ma. Both ~160 and ~175 Ma age populations show excellent agreement between samples, indicating that the two distinctive cooling stages they record were synchronous on a regional scale. The ~175 Ma population is interpreted to record cooling in the footwall of rift-related faults and shear zones, for which widespread activity in the Lower Jurassic has been documented along the western margin of the Adriatic plate. The ~160 Ma age population postdates the activity of all known rift-related structures within the Adriatic margin, but coincides with extensive gabbroic magmatism and exhumation of sub-continental mantle to the floor of the Alpine Tethys, west of the Ivrea Zone. We propose that this ~160 Ma early post-rift age population records regional cooling following episodic heating of the distal Adriatic margin, likely related to extreme lithospheric thinning and associated advection of the asthenosphere to shallow levels. The partial preservation of the ~175 Ma age cluster suggests that the post-rift (~160 Ma) heating pulse was of short duration. The regional consistency of the data presented here, which is in contrast to many other thermochronometers in the IVZ, demonstrates the value of the rutile U–Pb technique for probing the thermal evolution of high-grade metamorphic terrains. In the IVZ, a significant decoupling between Zr-in-rutile temperatures and U–Pb ages of rutile is observed, with the two systems recording events ~120 Ma apart.

Impact of Taylor-Aris diffusivity on analyte and system zone dispersion in CZE assessed by computer simulation and experimental validation.

Application of pressure-driven laminar flow has an impact on zone and boundary dispersion in open tubular CE. The GENTRANS dynamic simulator for electrophoresis was extended with Taylor-Aris diffusivity which accounts for dispersion due to the parabolic flow profile associated with pressure-driven flow. Effective diffusivity of analyte and system zones as functions of the capillary diameter and the amount of flow in comparison to molecular diffusion alone were studied for configurations with concomitant action of imposed hydrodynamic flow and electroosmosis. For selected examples under realistic experimental conditions, simulation data are compared with those monitored experimentally using modular CE setups featuring both capacitively coupled contactless conductivity and UV absorbance detection along a 50 μm id fused-silica capillary of 90 cm total length. The data presented indicate that inclusion of flow profile based Taylor-Aris diffusivity provides realistic simulation data for analyte and system peaks, particularly those monitored in CE with conductivity detection.