Facies control on diagenesis and fracturing in peritidal carbonates : an outcrop based study of lower cretaceous deposits from central east Oman

The links between depositional fabrics, diagenesis and fracture patterns are explored for the Barremian-Aptian Jurf and Qishn formations of central east Oman. Field, petrographic and analytical (oxygen and carbon isotopic ratios, clumped isotopes, strontium isotopes, major and trace elements, tensile strength) data were acquired. The excellent outcrop exposures allow the investigation of the geometries, dimensions and spatial distributions of sedimentary bodies, diagenetic bodies and fractures at the inter-well scale (one kilometre). It is suggested that in the Late Barremian, storm and wave reworking and transport were the dominant sedimentary processes operating in the peritidal environment of the southern Tethyan platform. The stratigraphic distribution of the parasequences and discontinuity surface types suggest some regional sea level control on the peritidal carbonate cyclicity. Pervasive dolomite is restricted to the Jurf Formation transgressive systems tract, which is characterized by a peritidal environment rich in microbial mats. Other system tracts, despite being composed of peritidal facies with evidence for high salinities, were not dolomitized, suggesting that the presence of microbial mats, i.e. the depositional fabric, exerted a major control on dolomite distribution. Spacing and orientation of fractures in limestones also depend strongly on the depositional fabric. Grain-supported facies, such as grainstones and rudstones, develop closely and evenly spaced northwestsoutheast oriented stratabound fractures; whereas mud-supported facies develop widely and unevenly spaced throughgoing fractures predominantly oriented north-south. It is suggested that fractures developed until fracture saturation in early cemented grain-supported facies during the Late Cretaceous. As burial increased, the bedding interfaces become stronger allowing for the development of throughgoing fractures that cross-cut mud-supported beds, which remained undersaturated with respect to fractures. This study shows that diagenetic heterogeneities of the Jurf and Qishn formations are strongly linked to depositional heterogeneities, and that both the depositional fabric and early diagenesis control the distribution of fracture heterogeneities

Sites for health rights: Local, national, regional and global

This Part-Special Issue seeks to capitalize on emerging work at the intersection of studies of global health, the right to health and ‘the spatial turn’ in the social sciences. The articles included address globally applicable research from a range of disciplines. The relevance of the right to health cuts across traditional disciplinary boundaries. The Part-Special Issue contributes to debates by presenting empirical and theoretical work from public health, social policy, political science, geography, anthropology and socio-legal studies. Attention to the right to health has increased in the last three decades mainly due to HIV/AIDS. Nevertheless, the spatial component of how to implement the right to health has been neglected by researchers, policy makers and practitioners compared to other, legal aspects of the right to health

High-entropy high-hardness metal carbides discovered by entropy descriptors

High-entropy materials have attracted considerable interest due to the combination of useful properties and promising applications. Predicting their formation remains the major hindrance to the discovery of new systems. Here we propose a descriptor - entropy forming ability - for addressing synthesizability from first principles. The formalism, based on the energy distribution spectrum of randomized calculations, captures the accessibility of equally-sampled states near the ground state and quantifies configurational disorder capable of stabilizing high-entropy homogeneous phases. The methodology is applied to disordered refractory 5-metal carbides - promising candidates for high-hardness applications. The descriptor correctly predicts the ease with which compositions can be experimentally synthesized as rock-salt high-entropy homogeneous phases, validating the ansatz, and in some cases, going beyond intuition. Several of these materials exhibit hardness up to 50% higher than rule of mixtures estimations. The entropy descriptor method has the potential to accelerate the search for high-entropy systems by rationally combining first principles with experimental synthesis and characterization.Comment: 12 pages, 2 figure

Simulated Ecological Environments for Education: A Tripartite Model Framework of HCI Design Parameters for Situational Learning in Virtual Environments

While there are many studies on collaborative or guided scientific inquiry in real, virtual,and simulated environments, there are few that study the interplay between the design ofthe simulation and the user interface. The main research aim was to decompose thesimulation and user interface into the design parameters that influence attention,curiosity, inquiry, and learning of scientific material and acts of creation for children.The research design investigates what tools support independent exploration of a space,enhance deep learning, and motivate scientific or creative inquiry. A major interest is inthe role that ecological context plays in the perception of spatial information.None of the prior work on learning in virtual environments considered a child-centriccomputer interaction framing, independent of pedagogy and focused on the impact ofuser interface parameters, such as image quality and navigational freedom. A majorcontribution of this research is the construction of the Virtual Trillium Trail, as itrepresents one square mile of biologically accurate scientific plot study data. It is avirtual environment based on statistical data visualization, not fantasy. It allowed for ahighly realistic simulation and scientifically true-to-life visualization, as well as for aplanned orthogonal contrast with exceptionally high internal validity in both system andstatistical research design.Of critical importance is evidence in the pilot study, that virtual reality field trips forstudents may be used to prime before and to reinforce after a real field trip. Thisresearch also showed transfer effects on in-situ learning activity, in both directions.Thus, supports the claim that virtual environments may augment educational practices,not replace them, to maximize the overall learning impact. The other large contributionwas in the activity analysis of the real field trip, where the Salamander Effect is observedas an environmental event, which opened a Teachable Moment event for the teacher, andwhich was then translated into a system design feature, a Salient Event in the userinterface. A main part of this research is the importance of such events, as ways tosupport intrinsic learning activity, and leverage episodic memory.The main empirical contribution to the design of educational virtual environments wasproduced by the 2 x 2 ANOVA with the factors of Visual Fidelity and NavigationalFreedom, set to high and low levels, and the evidence of different effects on KnowledgeGained. The tool has an impact on intrinsic learning, which is measured here by a pretestand a post-test on facts and concepts. A two-factor analysis of variance showed asignificant effect of Visual Fidelity on Knowledge Gained, F(1,60) = 10.54, p = 0.0019.High Visual Fidelity condition has a greater impact on Knowledge Gained (M=30.95, SD=14.76), than Low Visual Fidelity condition (M=19.99, SD = 13.39). Photorealistic has astronger impact on learning than cartoon versions. There was significant interactionbetween Visual Fidelity and Navigational Freedom, F(1,60) = 4.85, p = 0.0315, with thelargest impact in the combined conditions of High Visual Fidelity and High NavigationalFreedom on Knowledge Gained (M=37.44, SD = 13.88). Thus, photorealistic, freenavigation virtual environments double learning, when compared to cartoon versions,ceteris paribus.The next major contribution to the design of the user interface in educational virtualenvironments is the design and use of Salient Events as components to augment thevirtual environment and to facilitate intrinsic inquiry into facts and concepts. A two factoranalysis of variance showed a significant effect of Visual Fidelity on Salient Eventcounts, F(1,60) = 4.35, p = 0.00413. High Visual Fidelity condition has a greater impacton Salient Event counts, (Μ = 14.46, SD = 6), than Low Visual Fidelity condition,(Μ =11.31, SD = 6.37). Using High Visual Fidelity with High Navigational Freedom(showing a strong trend of F(1,60) = 3.23, p = 0.0773) to increase Salient Event countsare critical design features for educational virtual environments, especially since SalientEvents are moderately positively correlated with Knowledge Gained (r = 0.455, N = 64, p= 0.000).Emotional, affective, aesthetic, and subjective attitudes were investigated in the post-experience assessment of the main study on system and learning experience. TotalAttitude is strongly positively and significantly correlated with Awe and Wonder (r =0.727, N = 64, p = 0.000). Also important is the strong, positive, and significantcorrelation of Beauty with Awe and Wonder (r = 0.506, N = 64, p = 0.000). And the onlysignificant subjective emotion or attitude variable correlated to Knowledge Gained, wasAwe and Wonder with a slightly positive statistic: (r = 0.273, N = 64, p = 0.000).Future research will investigate the complexity and causality of such interactions betweenthe child's mental model, the virtual environment, and the user interface in the form ofregression equations, partial differential equations, and Markov models

Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements

A photometric and spectroscopic analysis of 152 cool white dwarf stars is presented. The discovery of 7 new DA white dwarfs, 2 new DQ white dwarfs, 1 new magnetic white dwarf, and 3 weak magnetic white dwarf candidates, is reported, as well as 19 known or suspected double degenerates. The photometric energy distributions, the Halpha line profiles, and the trigonometric parallax measurements are combined and compared to model atmosphere calculations to determine the effective temperature and the radius of each object, and also to constrain the atmospheric composition. New evolutionary sequences with C/O cores with thin and thick hydrogen layers are used to derive masses and ages. We confirm the existence of a range in Teff between 5000 and 6000K where almost all white dwarfs have H-rich atmospheres. There is little evidence for mixed H/He dwarfs, with the exception of 2 He-rich DA stars, and 5 C2H white dwarfs which possibly have mixed H/He/C atmospheres. The DQ sequence terminates near 6500K, below which they are believed to turn into C2H stars. True DC stars slightly above this temperature are found to exhibit H-like energy distributions despite the lack of Halpha absorption. Attempts to interpret the chemical evolution show the problem to be complex. Convective mixing is necessary to account for the non-DA to DA ratio as a function of temperature. The presence of helium in cool DA stars, the existence of the non-DA gap, and the peculiar DC stars are also explained in terms of convective mixing, although our understanding of how this mechanism works needs to be revised. The oldest object in our sample is about 7.9 Gyr or 9.7 Gyr old depending on whether thin or thick hydrogen layer models are used. The mean mass of our sample is 0.65 +/- 0.20 Msun.Comment: Accepted by ApJ Suppl (~April 2001); 79 pages incl. 25 figure

The right to traditional, complementary, and alternative health care

BackgroundState parties to human rights conventions and declarations are often faced with the seemingly contradictory problem of having an obligation to protect people from harmful practices while also having an obligation to enable access to culturally appropriate effective healing. As people increasingly migrate across the globe, previous distinctions between ‘traditional’ and ‘complementary and alternative medicine’ practices are being transcended. There are connections across transnational healing pathways that link local, national, and global movements of people and knowledge.ObjectiveThis paper contributes to the development of the concept and practice of the right to health in all its forms, exploring the right to traditional, complementary, and alternative health (R2TCAH) across different contexts.DesignThe paper draws on four settings – England, South Africa, Kenya, and Jordan – and is based on key informant interviews and a literature review undertaken in 2010, and updated in 2013. The paper begins by reviewing the international legal context for the right to health. It then considers legal and professional regulations from the global north and south.ResultsAdditional research is needed to establish the legal basis, compare regulatory frameworks, and explore patient and provider perspectives of regulation. This leads to being able to make recommendations on how to balance protection from harm and the obligation to ensure culturally appropriate services. Such an exploration must also challenge Western theories of human rights. Key concepts, such as individual harm, consent, and respect of the autonomy of the individual already established and recognised in international health law, could be adopted in the development of a template for future comparative research.ConclusionsExploration of the normative content of the right to health in all its forms will contribute to supporting traditional, complementary, and alternative health service users and providers in terms of access to information, non-discrimination, clarification of state obligations, and accountability

Working on an institutional repository: cataloguer, metadata specialist or something else?

The Cardiff University repository team is currently part of a wider research support team that includes Open Access funding and advocacy, research analytics, and the recently-established Cardiff University Press. The team consist of librarians and library staff who come from a wide variety of backgrounds: while the Repository Manager does come from a cataloguing background, the other team members originally worked as library and IT assistants or as library service managers, while several of us have subject librarian experience. Certainly, at Cardiff, we have found that the institutional repository role has widened out from a branch of cataloguing and metadata to one that involves more advocacy, training and direct customer interaction. One thing all of us have in common though is that we enjoy the detailed work involved in creating a perfect metadata record, while a subject specialist background is also useful as you get to know the subject resources and the researchers well, so will have some idea where to find elusive information to create or edit that perfect record

Topological descriptors for coral reef resilience using a stochastic spatial model

A complex interplay between species governs the evolution of spatial patterns in ecology. An open problem in the biological sciences is characterizing spatio-temporal data and understanding how changes at the local scale affect global dynamics/behavior. We present a toolkit of multiscale methods and use them to analyze coral reef resilience and dynamics.Here, we extend a well-studied temporal mathematical model of coral reef dynamics to include stochastic and spatial interactions and then generate data to study different ecological scenarios. We present descriptors to characterize patterns in heterogeneous spatio-temporal data surpassing spatially averaged measures. We apply these descriptors to simulated coral data and demonstrate the utility of two topological data analysis techniques--persistent homology and zigzag persistence--for characterizing the spatiotemporal evolution of reefs and generating insight into mechanisms of reef resilience. We show that the introduction of local competition between species leads to the appearance of coral clusters in the reef. Furthermore, we use our analyses to distinguish the temporal dynamics that stem from different initial configurations of coral, showing that the neighborhood composition of coral sites determines their long-term survival. Finally, we use zigzag persistence to quantify spatial behavior in the metastable regime as the level of fish grazing on algae varies and determine which spatial configurations protect coral from extinction in different environments

First principles computational descriptor for entropy forming ability

Entropy stabilized materials [1], where the mixing of the components is driven by configurational entropy rather than formation enthalpy, are potential candidates for ultra-high temperature applications. The prediction of which compositions will form entropy stabilized materials is difficult since calculating the entropic contribution to the free energy from first principles is computationally expensive. Therefore, we have formulated a descriptor for the synthesizability of disordered materials based on the energy distribution of the thermodynamic density of states (TDOS) for an ensemble of ordered configurations generated using the AFLOW (Automatic FLOW) partial occupation (AFLOW-POCC) methodology [2,3] and calculated with DFT. This descriptor has been used to successfully predict which refractory metal carbide compositions can be experimentally synthesized as single-phase entropy stabilized materials [4]. This work is supported by the U.S. Office of Naval Research MURI program (grant No. N00014-15- 1-2863). [1] C. M. Rost, E. Sachet, T. Borman, A. Moballegh, E. C. Dickey, D. Hou, J. L. Jones, S. Curtarolo, and J.-P. Maria, Entropy Stabilized Oxides, Nat. Commun. 6, 8485 (2015). [2] S. Curtarolo, W. Setyawan, G. L. W. Hart, M. Jahnatek, R. V. Chepulskii, R. H. Taylor, S. Wang, J. Xue, K. Yang, O. Levy, M. J. Mehl, H. T. Stokes, D. O. Demchenko, and D. Morgan, AFLOW: an automatic framework for high-throughput materials discovery, Comput. Mater. Sci. 58, 218-226 (2012). [3] K. Yang, C. Oses, and S. Curtarolo, Modeling off-stoichiometry materials with a high-throughput ab-initio approach, Chem. Mater. 28, 6484-6492 (2016). [4] P. Sarker, T. Harrington, C. Toher, K. Vecchio, and S. Curtarolo, First principles materials design using a spectral descriptor for entropy forming ability, in preparation (2017)