Structural control of inherited salt structures during inversion of a domino basement-fault system from an analogue modelling approach

The geometries of inverted rift systems are different depending on a large variety of factors that include, among others, the presence of decoupling layers, the thickness of the pre- and syn-extension successions, or structural inheritances. Our study focuses on the inversion of an extensional domino-style basement-fault system with a pre-extension salt layer using analogue models to understand the role of pre-existing structural features during inversion. Models investigate how different overburden and salt thicknesses, inherited extensional structures, and salt distributions condition the evolution during inversion. The experimental results show that models with thick salt can partially or totally preserve the extensional ramp–syncline basin geometry independently of the overburden thickness. In contrast, models with a thin salt layer result in a total inversion of the ramp–syncline basins with the development of crestal collapse grabens and extensional faults affecting the overburden. Inversion also triggered the growth or reactivation of salt-related structures such as primary weld reopening and/or obliteration, diapir rejuvenation, salt thickening, or thrust emplacement. The use of analogue modelling allowed us to address the processes that controlled the growth and evolution of these structural elements during the inversion. Experimental results also provide a template of different structural styles resulting from the positive inversion of basins with a pre-extensional salt layer that can help subsurface interpretation in areas with poor seismic imaging.</p

Tectonostratigraphic Evolution of the orange basin, sw Africa

The Orange Basin is a Late Jurassic to present day basin located on the volcanic-rifted passive margin of SW Africa. 2D seismic data and structural restoration techniques were used to develop a tectonostratigraphic model of the basin consisting of a syn-rift and a post-rift megasequences separated by an Early Cretaceous break-up unconformity. The post-rift megasequence is characterised by gravity tectonics where extensional faults transferred displacement downdip into a deep water fold and thrust belt (DWFTB). Gravity gliding tectonics occurred through a combination of cratonic uplift and thermal subsidence and stopped via deltaic progradation and associated differential sedimentary loading

Impact on Student Attitudes through Participation in Interprofessional Student Teams at a Remote Area Medical Event in Rural Appalachia

Interprofessional teamwork is being adopted as the best way to care for patients, but it is also important to determine how future healthcare providers view this model of patient care. What are their attitudes and beliefs after having the opportunity to work in an interprofessional team? The primary objective of this study was to determine changes in health profession students’ attitudes toward interprofessional collaboration through participation in a Remote Area Medical (RAM) event in rural Appalachia. Researchers hypothesized that working in interprofessional teams positively impacts students’ attitudes toward interprofessional practice. To explore these variables, RedCap was utilized to collect demographic information, generate a pre/post survey matching code, and administer previously validated interprofessional education (IPE) questionnaires to RAM clinic student volunteers (representing five ETSU health sciences colleges and various undergraduate programs) before and after the event. Students were allowed to voluntarily complete the pre-survey online prior to participating in the event or at sign-in and the post-survey at sign-out or online after the event. The Student Perceptions of Interprofessional Clinical Education-Revised Instrument, Version 2 (SPICE-R2), which is validated for use in pre- and post-surveys, utilized 5-point Likert-type questions (strongly disagree to strongly agree) to evaluate students’ perceptions of their role on the team and the team’s impact on healthcare and patient outcomes. The Interprofessional Collaborative Competency Attainment Scale-Revised (ICCAS-R), which is only validated for use in post-surveys, required students to simultaneously evaluate their ability to perform tangible interprofessional team skills before and after the event using 5-point Likert-type questions (poor to excellent). At the event, students were placed into interprofessional teams to provide care to patients. Faculty members from a variety of professions provided leadership to the teams and guidance as needed. The pre-survey had 107 responses and the post-survey had 108 responses. However, after matching the pre- and post-surveys with student-generated codes, there were 70 valid matched responses. Data analysis was conducted using SPSS version 25. There were no statistically significant changes in SPICE-R2 IPE constructs from the pre-survey to post-survey. However, high pre-survey scores indicated that this student cohort already had a high level of appreciation for interprofessional teams, with mean scores of 4.5 out of 5 for teamwork, 4 out of 5 for roles and responsibilities, and 4.36 out of 5 for healthcare outcomes. The mean overall composite score on the ICCAS-R increased from 3.65 out of 5 on the pre-event portion to 4.03 out of 5 on the post-event portion (p \u3c 0.001) , indicating that students increased their self-evaluated ability to perform tangible skills used in the interprofessional team through participation in the RAM clinic. Findings of this research may allow educators in both classroom and healthcare settings to better understand how hands-on IPE experiences influence students’ interprofessional attitudes and beliefs

Influence of fault geometries and mechanical anisotropies on the growth and inversion of hanging-wall synclinal basins: insights from sandbox models and natural examples

Salt is mechanically weaker than other sedimentary rocks in rift basins. It commonly acts as a strain localizer, and decouples supra- and sub-salt deformation. In the rift basins discussed in this paper, sub-salt faults commonly form wide and deep ramp synclines controlled by the thickness and strength of the overlying salt section, as well as by the shapes of the extensional faults, and the magnitudes and slip rates along the faults. Upon inversion of these rift basins, the inherited extensional architectures, and particularly the continuity of the salt section, significantly controls the later contractional deformation. This paper utilizes scaled sandbox models to analyse the interplay between sub-salt structures and supra-salt units during both extension and inversion. Series 1 experiments involved baseline models run using isotropic sand packs for simple and ramp-flat listric faults, as well as for simple planar and kinked planar faults. Series 2 experiments involved the same fault geometries but also included a pre-extension polymer layer to simulate salt in the stratigraphy. In these experiments, the polymer layer decoupled the extensional and contractional strains, and inhibited the upwards propagation of sub-polymer faults. In all Series 2 experiments, the extension produced a synclinal hanging-wall basin above the polymer layer as a result of polymer migration during the deformation. During inversion, the supra-polymer synclinal basin was uplifted, folded and detached above the polymer layer. Changes in thickness of the polymer layer during the inversion produced primary welds and these permitted the sub-polymer deformation to propagate upwards into the supra-salt layers. The experimental results are compared with examples from the Parentis Basin (Bay of Biscay), the Broad Fourteens Basin (southern North Sea), the Feda Graben (central North Sea) and the Cameros Basin (Iberian Range, Spain)

Scaled physical models of continental rifting: application to the Baikal Rift Zone

Scaled physical models constructed with dry sand layers have proven to be a useful tool for the simulation of the structural patterns that are commonly observed in natural rift systems. With this study we have tried to simulate the evolution of the Baikal Rift Zone as to get better insight in the importance of some of the processes controlling its development. For this purpose, models have been constructed with different baseplate geometries. These models allowed us to observe the possible basement controls on the present-day fault structures in the Baikal Rift Zone.Baseplates having similar shapes as the Siberian Craton caused in the models the development of the stepwise fault deflection that is characteristic for the western border fault system of Lake Baikal. During the initial evolution of the modelled faults, several relay zones were formed between isolated fault segments. Such relay zones are also common in the border fault system of Lake Baikal. In later stages of the modelling, further extension lead to the linkage between fault segments, causing the eventual disappearance of the different relay zones.The development of the models was continuously monitored using digital photographs. Animating the sequence of these photographs allowed to carefully study the kinematic evolution of the experiments. After certain amounts of extension (usually 1 or 2cm) the different basins that had formed in the models were filled with syn-kinematic sand layers. Completed models have subsequently been impregnated and sectioned either vertically or horizontally in 1cm intervals. This technique reveals the internal geometry of the formed fault structures. 3D reconstructions of the models have been produced by digitising certain reference levels on the different crosssections.Such 3D images clearly illustrate the variations in fault displacements in the different parts of the models. Moreover, 3-dimensional representations of the experiments can easily be compared with the available digital terrain models of the Baikal Rift Zone, to test the validity of the modelling results.In this study we have examined in detail the kinematic evolution and the growth of faults in different sandbox experiments, and we have compared our observations with structural interpretations that have already been made for the Baikal Rift Zone

Phase II study of second-line therapy with DTIC, BCNU, cisplatin and tamoxifen (Dartmouth regimen) chemotherapy in patients with malignant melanoma previously treated with dacarbazine

This study assessed response rates to combination dacarbazine (DTIC), BCNU (carmustine), cisplatin and tamoxifen (DBPT) chemotherapy in patients with progressive metastatic melanoma previously treated with DTIC, as an evaluation of DBPT as a second-line regimen, and as an indirect comparison of DBPT with DTIC. Thirty-five consecutive patients received DBPT. The patients were divided into two groups. Group 1 comprised 17 patients with progressive disease (PD) on DTIC + tamoxifen therapy who were switched directly to DBPT. Group 2 comprised 18 patients not immediately switched to DBPT and included patients who had either a partial response (PR; one patient) or developed stable disease (SD; four patients) with DTIC, or received adjuvant DTIC (nine patients). All except four patients had received tamoxifen at the time of initial DTIC treatment. Median times since stopping DTIC were 22 days (range 20–41) and 285 days (range 50–1240) in Groups 1 and 2 respectively. In Group 1, one patient developed SD for 5 months and the remainder had PD. In Group 2, there were two PRs, four patients with SD (4, 5, 6, and 6 months), and 11 with PD. These results indicate that the DBPT regimen is not of value in melanoma primarily refractory to DTIC. There were responses in patients not directly switched from DTIC to DBPT, suggesting combination therapy may be of value in a small subgroup of melanoma patients. © 2000 Cancer Research Campaig

Perceptions of Risk for COVID-19 Among Individuals With Chronic Diseases and Stakeholders in Central Appalachia

Coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving and is a serious public health threat worldwide. Timely and effective control of the pandemic is highly dependent on preventive approaches. Perception of risk is a major determinant of health behavior. The current study explores the association between actual risk and perceived risk for one’s self, family/friends and friends, and community. A questionnaire was administered to participants in Central Appalachia (n = 102). The actual risk was based on the number of chronic conditions of the following conditions: hypertension, heart disease, cancer, diabetes, and chronic obstructive pulmonary disease. Participants were also queried about their perception of risk for COVID-19. Generalized Linear Models were used to independently evaluate the likelihood of perceived risk for one’s: self, family/friends, and community, based on actual risk. Actual risk for COVID-19 was significantly associated with higher likelihood of higher perception of risk for one’s self (b = 0.24; p = 0.04), but not with one’s family/friends (b = 0.05; p = 0.68), or one’s community (b = 0.14; p = 0.16). No health insurance was negatively associated with perception of risk for self (b = −0.59; p = 0.04) and family/friends (b = −0.92; p \u3c 0.001). Male gender (b = −0.47; p = 0.01) was also negatively associated with perception of risk for family/friends. In conclusion, individuals’ actual risk for COVID-19 is associated with their own perception of risk. This indicates that one’s perception of risk for COVID-19 is greater for their own health compared to their family/friends or the community. Therefore, monitoring and following up with chronic disease patients and addressing their lack of awareness of risk to others is needed to prevent and curtail the spread of COVID-19

Weld kinematics of synrift salt during basement-involved extension and subsequent inversion: Results from analog models

Scaled analog models based on extensional basins with synrift salt show how basement topography exerts a control factor on weld kinematics during the extension and inversion phases. In the case of basement-involved extension, syn-rift salt thickness differences may lead to variable degrees of extensional decoupling between basement topography and overburden, which in turn have a strong impact on the development of salt structures. With ongoing extension and after welding, the basin kinematics evolves toward a coupled deformation style. The basin architecture of our experimental results record the halokinetic activity related to growing diapirs and the timing of weld formation during extension. Moreover, the structures that result from any subsequent inversion of these basins strongly depends on the inherited welds and salt structures. While those basins are uplifted, the main contractional deformation during inversion is absorbed by the pre-existing salt structures, whose are squeezed developing secondary welds that often evolve into thrust welds. The analysis of our analog models shows that shortening of diapirs is favored by: 1) basement topography changes that induce reactivation of primary welds as thrust welds; 2) reactivation of the salt unit as a contractional detachment; and 3) synkinematic sedimentation during basin inversion. Finally in this article we also compare two natural examples from the southern North Sea that highlight deformation patterns very similar to those observed in our analog models