293 research outputs found

    Split SUSY Radiates Flavor

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    Radiative flavor models where the hierarchies of Standard Model (SM) fermion masses and mixings are explained via loop corrections are elegant ways to solve the SM flavor puzzle. Here we build such a model in the context of Mini-Split Supersymmetry (SUSY) where both flavor and SUSY breaking occur at a scale of 1000 TeV. This model is consistent with the observed Higgs mass, unification, and WIMP dark matter. The high scale allows large flavor mixing among the sfermions, which provides part of the mechanism for radiative flavor generation. In the deep UV, all flavors are treated democratically, but at the SUSY breaking scale, the third, second, and first generation Yukawa couplings are generated at tree level, one loop, and two loops, respectively. Save for one, all the dimensionless parameters in the theory are O(1), with the exception being a modest and technically natural tuning that explains both the smallness of the bottom Yukawa coupling and the largeness of the Cabibbo angle.Comment: 55 pages, 14 figures. v2: Typos fixed and references added. v3: More typos fixed and figure correcte

    Providing guidance on Backstage, a novel digital backchannel for large class teaching

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    Many articles in the last couple of years argued that it is necessary to promote the active participation of students in lectures with large audiences. One approach to make students actively participate in a lecture is to use a digital backchannel, i.e. a computer-mediated communication platform that allows students to exchange ideas and opinions, without disrupting the lecturer’s discourse. Though, a digital backchannel, in order to be most helpful for learning, have to address the need for guidance of the users interacting. The article presents Backstage, a digital backchannel for large class lectures, and shows how it provides guidance for its users, i.e. the students but also the lecturer. Structural guidance is provided by aligning the usually incoherent backchannel discourse with the presentation slides that are integrated in the backchannel’s user interface. The alignment is thereby asserted by carefully designed backchannel workflows. The article also discusses the guidance of a student’s substantial involvement in both the frontchannel and the backchannel by means of scripts. Through the interactions of guided individuals a social guidance may emerge, leading to a collectively regulated backchannel

    The Expenditures for Academic Inpatient Care of Inflammatory Bowel Disease Patients Are Almost Double Compared with Average Academic Gastroenterology and Hepatology Cases and Not Fully Recovered by Diagnosis-Related Group (DRG) Proceeds

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    Background Crohn’s disease (CD) and ulcerative colitis (UC) challenge economies worldwide. Detailed health economic data of DRG based academic inpatient care for inflammatory bowel disease (IBD) patients in Europe is unavailable. Methods IBD was identified through ICD-10 K50 and K51 code groups. We took an actual costing approach, compared expenditures to G-DRG and non-DRG proceeds and performed detailed cost center and type accounting to identify coverage determinants. Results Of all 3093 hospitalized cases at our department, 164 were CD and 157 UC inpatients in 2012. On average, they were 44.1 (CD 44.9 UC 43.3 all 58) years old, stayed 10.1 (CD 11.8 UC 8.4 vs. all 8) days, carried 5.8 (CD 6.4 UC 5.2 vs. all 6.8) secondary diagnoses, received 7.4 (CD 7.7 UC 7 vs. all 6.2) procedures, had a higher cost weight (CD 2.8 UC 2.4 vs. all 1.6) and required more intense nursing. Their care was more costly (means: total cost IBD 8477€ CD 9051€ UC 7903€ vs. all 5078€). However, expenditures were not fully recovered by DRG proceeds (means: IBD 7413€, CD 8441€, UC 6384€ vs all 4758€). We discovered substantial disease specific mismatches in cost centers and types and identified the medical ward personnel and materials budgets to be most imbalanced. Non-DRG proceeds were almost double (IBD 16.1% vs. all 8.2%), but did not balance deficits at total coverage analysis, that found medications (antimicrobials, biologics and blood products), medical materials (mostly endoscopy items) to contribute most to the deficit. Conclusions DRGs challenge sophisticated IBD care

    Crohn's disease

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    SummaryCrohn's disease is a relapsing systemic inflammatory disease, mainly affecting the gastrointestinal tract with extraintestinal manifestations and associated immune disorders. Genome wide association studies identified susceptibility loci that—triggered by environmental factors—result in a disturbed innate (ie, disturbed intestinal barrier, Paneth cell dysfunction, endoplasmic reticulum stress, defective unfolded protein response and autophagy, impaired recognition of microbes by pattern recognition receptors, such as nucleotide binding domain and Toll like receptors on dendritic cells and macrophages) and adaptive (ie, imbalance of effector and regulatory T cells and cytokines, migration and retention of leukocytes) immune response towards a diminished diversity of commensal microbiota. We discuss the epidemiology, immunobiology, amd natural history of Crohn's disease; describe new treatment goals and risk stratification of patients; and provide an evidence based rational approach to diagnosis (ie, work-up algorithm, new imaging methods [ie, enhanced endoscopy, ultrasound, MRI and CT] and biomarkers), management, evolving therapeutic targets (ie, integrins, chemokine receptors, cell-based and stem-cell-based therapies), prevention, and surveillance

    On-Orbit Performance of the BCT XB-1 Spacecraft and GN&C Components

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    Blue Canyon Technologies (BCT) currently has a variety of hardware operating in space with multiple missions launched in 2016. The deployment of the Miniature X-ray Solar Spectrometer (MinXSS) 3U CubeSat from ISS on May 16, 2016 was the first mission to operate the high accuracy pointing, complete GN&C subsystem XACT. The first on-orbit operation of the BCT XB-1 spacecraft bus occurred with the launch of the APL Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) 3U Cubesat on November 11, 2016. Finally, the NASA Cyclone Global Navigation Satellite System (CYGNSS) constellation of eight microsatellites was deployed from an Orbital ATK Pegasus XL rocket on December 15, 2016 and each spacecraft has a BCT Nano Star Tracker and three p015 reaction wheels. This paper reviews on-orbit performance of these components and systems. Detailed analysis of on-orbit telemetry is used to assess performance, with an emphasis on pointing accuracy but also including momentum control, safe mode operations, and other aspects. The results indicate a variety of solutions, ranging from high performing GN&C components to a complete spacecraft bus, capable of providing high-accuracy pointing for small satellites

    Biological Therapies in Immune-Mediated Inflammatory Diseases: Can Biosimilars Reduce Access Inequities?

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    Biological therapies are an effective treatment for a range of immune-mediated inflammatory diseases (IMIDs), including rheumatoid arthritis, psoriasis, and inflammatory bowel diseases. However, due to their high costs, considerable differences in their utilization exist across the world, even among the various European countries, with many countries restricting access despite professional society guideline recommendations. Adoption of biologics by healthcare providers has been particularly poor in many Central and Eastern European countries. Differences in utilization have also been observed across medical specialties, healthcare providers, and at a regional and national level. The objective of this paper is to provide an overview of the different market access policies for biologics in Europe and to investigate reasons for such differences. One of the potential solutions for providing broader access to IMID patients, where cost is the major barrier, is to encourage the use of biosimilars in place of their reference products. Biosimilars are generally less expensive alternatives to already licensed biological therapies and are approved on the basis that they are similar to the reference product in terms of quality, safety, and efficacy. Budget impact models predict considerable cost savings following the introduction of biosimilars in the next few years. These savings could be used to increase access to biologics and other innovative therapies

    Isoflurane Inhibits Synaptic Vesicle Exocytosis through Reduced Ca2+ Influx, not Ca2+-Exocytosis Coupling

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    Identifying presynaptic mechanisms of general anesthetics is critical to understanding their effects on synaptic transmission. We show that the volatile anesthetic isoflurane inhibits synaptic vesicle (SV) exocytosis at nerve terminals in dissociated rat hippocampal neurons through inhibition of presynaptic Ca2+ influx without significantly altering the Ca2+ sensitivity of SV exocytosis. A clinically relevant concentration of isoflurane (0.7 mM) inhibited changes in [Ca2+]i driven by single action potentials (APs) by 25 ± 3%, which in turn led to 62 ± 3% inhibition of single AP-triggered exocytosis at 4 mM extracellular Ca2+ ([Ca2+]e). Lowering external Ca2+ to match the isoflurane-induced reduction in Ca2+ entry led to an equivalent reduction in exocytosis. These data thus indicate that anesthetic inhibition of neurotransmitter release from small SVs occurs primarily through reduced axon terminal Ca2+ entry without significant direct effects on Ca2+-exocytosis coupling or on the SV fusion machinery. Isoflurane inhibition of exocytosis and Ca2+ influx was greater in glutamatergic compared with GABAergic nerve terminals, consistent with selective inhibition of excitatory synaptic transmission. Such alteration in the balance of excitatory to inhibitory transmission could mediate reduced neuronal interactions and network-selective effects observed in the anesthetized central nervous system

    MinXSS CubeSat On-Orbit Performance and the First Flight of the Blue Canyon Technologies XACT 3- axis ADCS

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    The Miniature X-ray Solar Spectrometer (MinXSS) 3U CubeSat was launched to the International Space Station (ISS) on 2015 December 6. Its deployment from the ISS is scheduled for 2016 March. MinXSS was designed and developed at the University of Colorado Boulder through a graduate project class, with significant professional support from the Laboratory for Atmospheric and Space Physics (LASP). The 3- axis attitude determination and control system (ADCS) is the Blue Canyon Technologies (BCT) XACT. This is the first flight of the XACT unit, which is the most capable commercially available 3-axis ADCS for CubeSats on the market today. MinXSS is a science mission funded by NASA\u27s Heliophysics division and is the first CubeSat to be flown from NASA Science Mission Directorate\u27s new CubeSat Implementation Panel. The primary objective for the MinXSS mission is to better understand the energy distribution of solar soft x-ray (SXR) emissions and their impact on earth\u27s ionosphere, thermosphere, and mesosphere (ITM). MinXSS observes the solar SXR spectrum between 0.5 to 30 keV with an energy resolution of 0.15 keV full width half maximum at 5.9 keV. Very few prior spectrally-resolved solar observations exist in the SXR range, leaving a critical gap in our ability to determine the spectral energy distribution for ITM modeling and solar flare studies. These issues can be addressed with new MinXSS data. This paper will provide details of the on-orbit performance of MinXSS and first-light observations from the primary science instrument, which is a commercially available system that was modified for flight. First light observations will include the first solar SXR spectrum from MinXSS and comparisons between quiet-Sun and flare spectra as observed by MinXSS. MinXSS represents the first opportunity for on-orbit characterization of BCT\u27s XACT ADCS. Performance of star tracker-based attitude determination, 3-axis reaction wheel-based attitude control, and torque rod-based momentum control will be assessed using on-orbit telemetry. This system is being used by several NASA centers, the DoD, many universities, and commercial entities for a multitude of upcoming missions that require precision attitude control at low cost. The exceptionally simple design of the LASP PPPT will be reviewed. The addition of a single fixed-value resistor mitigates the high current draw from the battery, which prevents the solar cell voltage from dropping below buck converter input requirements. The PPPT was successful in increasing the power output of the electrical power system by nearly a factor of 2 in mission simulations. The on-orbit power performance will be analyzed. In addition to thermal vacuum testing, MinXSS underwent thermal balance, which is dedicated to tuning the thermal model. The thermal balance procedure and model will be briefly overviewed and predictions compared to on-orbit temperatures. The results of this analysis have been generalized such that other CubeSat programs, who may not have the means to perform the test, may apply the results to their models and get improved model predictions. Thermal control of CubeSats is important to their lifetime and few if any prior results on this topic have been previously presented

    Ion Mobility in Crystalline Battery Materials

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    Ion mobility in electrolytes and electrodes is an important performance parameter in electrochemical devices, particularly in batteries. In this review, the authors concentrate on the charge carrier mobility in crystalline battery materials where the diffusion basically corresponds to hopping processes between lattice sites. However, in spite of the seeming simplicity of the migration process in crystalline materials, the factors governing mobility in these materials are still debated. There are well-accepted factors contributing to the ion mobility such as the size and the charge of the ions, but they are not sufficient to yield a complete picture of ion mobility. In this review, possible factors influencing ion mobility in crystalline battery materials are critically discussed. To gain insights into these factors, chemical trends in batteries, both as far as the charge carriers as well as the host materials are concerned, are discussed. Furthermore, fundamental questions, for example, about the nature of the migrating charge carriers, are also addressed
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