2,997 research outputs found
Persistent topographic development along a strike-slip fault system: The Mount McKinley restraining bend
The Denali Fault is a major strike-slip fault extending from British Colombia, into western Alaska. Mount McKinley, at 6,114 m, is the highest peak in North America and is located to the south of a bend in the Denali Fault (Fig.1). To the north, at the apex of the bend in the fault, Peters Dome (3,221 m) is the highest peak and north-side peak elevations rapidly decrease moving away from the bend’s apex
Sorting Out a Promiscuous Superfamily: Towards Cadherin Connectomics
Members of the cadherin superfamily of proteins are involved in diverse biological processes such as morphogenesis, sound transduction, and neuronal connectivity. Key to cadherin function is their extracellular domain containing cadherin repeats, which can mediate interactions involved in adhesion and cell signaling. Recent cellular, biochemical, and structural studies have revealed that physical interaction among cadherins is more complex than originally thought. Here we review work on new cadherin complexes and discuss how the classification of the mammalian family can be used to search for additional cadherin-interacting partners. We also highlight some of the challenges in cadherin research; namely, the characterization of a cadherin connectome in biochemical and structural terms, as well as the elucidation of molecular mechanisms underlying the functional diversity of nonclassical cadherins in vivo.Molecular and Cellular Biolog
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
Distributed Sensor Logging: As Easy as a Mesh of Yoyos
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The Mass Gathering Data Acquisition and Analysis (MaGDAA) project involved the development of hardware and software solutions to facilitate the rapid and effective collection of autonomous and survey based data during mass gathering events. The aim of the project was the development and trial of a purpose-built Open Hardware based environment monitoring sensor prototypes using IOIO (pronounced “yoyo”) boards. Data from these sensors, and other devices, was collected using Open Source software running on Android powered mobile phones, tablets and other open hardware based platforms. Data was shared using a Wi-Fi mesh network based on an Open Source project called The Serval Project. Additional data in the form of survey based questionnaires were collected using ODK Collect, one of the applications in the Open Data Kit suite. The MaGDAA project demonstrated that it is possible for researchers (through the use of Open Source software and Open Hardware) to own, visualise, and share data without the difficulties of setting up and maintaining servers. MaGDAA proved to be an effective infrastructure independent sensor logging network that enables a broad range of data collection (demographic, predispositions, motivations, psychosocial and environmental influencers and modifiers of audience behaviour, cultural value) in the field of mass gathering research
The Polycomb protein, Bmi1, regulates insulin sensitivity
Objective: The Polycomb Repressive Complexes (PRC) 1 and 2 function to epigenetically repress target genes. The PRC1 component, Bmi1, plays a crucial role in maintenance of glucose homeostasis and beta cell mass through repression of the Ink4a/Arf locus. Here we have explored the role of Bmi1 in regulating glucose homeostasis in the adult animal, which had not been previously reported due to poor postnatal survival of Bmi1−/− mice. Methods: The metabolic phenotype of Bmi1+/− mice was characterized, both in vivo and ex vivo. Glucose and insulin tolerance tests and hyperinsulinemic-euglycemic clamps were performed. The insulin signaling pathway was assessed at the protein and transcript level. Results: Here we report a negative correlation between Bmi1 levels and insulin sensitivity in two models of insulin resistance, aging and liver-specific insulin receptor deficiency. Further, heterozygous loss of Bmi1 results in increased insulin sensitivity in adult mice, with no impact on body weight or composition. Hyperinsulinemic-euglycemic clamp reveals increased suppression of hepatic glucose production and increased glucose disposal rate, indicating elevated glucose uptake to peripheral tissues, in Bmi1+/− mice. Enhancement of insulin signaling, specifically an increase in Akt phosphorylation, in liver and, to a lesser extent, in muscle appears to contribute to this phenotype. Conclusions: Together, these data define a new role for Bmi1 in regulating insulin sensitivity via enhancement of Akt phosphorylation
Advanced Scanning Probe Microscopy for Materials Research
Scanning probe microscopy (SPM) encompasses a set of advanced techniques for mapping the structure and properties of the surfaces of materials from the atomic to micro scales. The most widely used SPM technique is atomic force microscopy (AFM), in which forces exerted between the tip of a needle probe and the sample surface can be measured with extremely high precision. By recording these forces as the tip rasters across the surface, an image of the sample surface topography is obtained. Beyond the surface topography, several SPM techniques can provide quantitative information about the properties of a material’s surface. These include scanning Kelvin probe force microscopy (KPFM) for surface potential measurements, scanning capacitance microscopy (SCM) for surface capacitance mapping, conductive and tunneling AFM (C-AFM and TUNA) for imaging the electrical conductance of a surface, as well as several techniques for imaging the mechanical properties of a surface. These advanced SPM techniques provide tools for direct structure-property correlations in materials at the nanoscale and are powerful capabilities for materials research, especially when co-located with other surface analytical techniques. Each of these advanced SPM techniques is available for materials research in the Boise State University Surface Science Laboratory
Canadian Theatre and the Tragic Experience of Evil
This essay examines the relevance of the tragic account of evil for Canadian theatre in the shadow of the contemporary "war on terror." It concentrates on two important aspects of the ancient Greek depiction of evil in tragedy: (1) that no agent, human or divine, is either absolutely good or absolutely evil; and (2) that evil, understood as the experience of dread, cannot be exterminated but can, at best, be kept within limits. In other words, the tragic account of evil is neither"melodramatic" nor"eschatological." The essay then discusses three recent Canadian plays that address current moral and geo-political issues: The Adventures of Ali & Ali and the aXes of Evil by Marcus Youssef, Guillermo Verdecchia, and Camyar Chai; Capture Me by Judith Thompson; and Insomnia by Daniel Brooks with Guillermo Verdecchia. Through these works, this essay explores how the experience of evil is currently being depicted and considers the possibilities for a new type of tragic theatre in Canada.
Résumé
Cet article a pour but d’examiner la pertinence de la représentation tragique du mal dans le théâtre canadien au regard de la guerre contemporaine contre le terrorisme. Il se concentre sur deux aspects importants de la représentation du mal dans le théâtre grec antique, soit : (1) qu’aucun agent, humain ou divin, n’est entièrement bon ou mauvais et (2) que le « mal, » c’est-à-dire l'expérience de la terreur, ne peut pas être détruite mais peut, au mieux, être limitée. En d’autres mots, la représentation tragique du mal n’est ni « mélodramatique, » ni « eschatologique. » L’article, par la suite, examine trois oeuvres canadiennes récentes qui traitent des questions morales et des problèmes géopolitiques contemporains, soit : The Adventures of Ali & Ali and the aXes of Evil de Marcus Youssef, Guillermo Verdecchia et Camyar Chai; Capture Me de Judith Thompson; et Insomnia de Daniel Brooks et Guillermo Verdecchia. À l’aide de ces œuvres, l’article étudie les possibilités d’avoir un nouveau genre de théâtre tragique au Canada, aborde la question de la représentation contemporaine de l’expérience du « mal »
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