8,443 research outputs found
Natural Scherk-Schwarz Theories of the Weak Scale
Natural supersymmetric theories of the weak scale are under growing pressure
given present LHC constraints, raising the question of whether untuned
supersymmetric (SUSY) solutions to the hierarchy problem are possible. In this
paper, we explore a class of 5-dimensional natural SUSY theories in which SUSY
is broken by the Scherk-Schwarz mechanism. We pedagogically explain how
Scherk-Schwarz elegantly solves the traditional problems of 4-dimensional SUSY
theories (based on the MSSM and its many variants) that usually result in an
unsettling level of fine-tuning. The minimal Scherk-Schwarz set up possesses
novel phenomenology, which we briefly outline. We show that achieving the
observed physical Higgs mass motivates extra structure that does not
significantly affect the level of tuning (always better than ) and
we explore three qualitatively different extensions: the addition of extra
matter that couples to the Higgs, an extra gauge group under
which the Higgs is charged and an NMSSM-like solution to the Higgs mass
problem.Comment: 36 pages + appendix, 12 figure
LA IMPORTANCIA DEL DISEÑO DE ESTRATEGIAS CONGRUENTES CON EL CONTEXTO LOCAL PARA INCREMENTAR LA INSERCIÓN LABORAL DE JÓVENES: UN ANÁLISIS DEL IMPACTO DE REDES SOCIALES EN EL SURESTE DE MÉXICO
Each day world statistics on youth unemployment increase and there is an apparent lack of clear agreement on strategies to curb the current trends. The International Labour Organisation reported in 2013 that were more than 73 million unemployed youths between 15 and 24 years old. We argue in this paper that public policy is not always best adapted to local contexts when it comes to actions to raise workplace insertion amongst this segment of the population. With reference to a study of university graduates in a public university in the southeast of Mexico, we evaluate the impact of national public policy which takes pertinence and quality of higher education programmes as the key factors that influence school to work transition; but we also evaluate the impact of a well-known and highly used local factor which is ignored by the public policy models, namely horizontal social networks. Alternative strategies are proposed on the basis of the results of this study and we close by generalising the lessons learned in this study to the problems of youth unemployment in general
Splenic non-Hodgkin’s lymphoma without organomegaly: occult presentation with fatal course and post-mortem diagnosis
Splenic lymphoma without splenomegaly is uncommon. We report the case of a 68-year-old female who presented with fulminant B symptoms and thrombocytopenia, only to be found to have micronodular large B-cell lymphoma of the spleen post-mortem. Diagnosis of this rare entity remains difficult and overall prognosis is poor
Enfoques metodologicos para identificar y caracterizar la investigacion mexicana en quimica en bases de datos bibliograficas
Numerical prediction of transition of the F-16 wing at supersonic speeds
A parametric study is being conducted as an effort to numerically predict the extent of natural laminar flow (NLF) on finite swept wings at supersonic speeds. This study is one aspect of a High Speed Research Program (HSRP) to gain an understanding of the technical requirements for high-speed aircraft flight. The parameters that are being addressed in this study are Reynolds number, angle of attack, and leading-edge wing sweep. These parameters were analyzed through the use of an advanced Computational Fluid Dynamics (CFD) flow solver, specifically the ARC 3-D Compressible Navier-Stokes (CNS) flow solver. From the CNS code, pressure coefficients (Cp) are obtained for the various cases. These Cp's are then used to compute the boundary-layer profiles through the use of the 'Kaups and Cebeci' compressible 2-D boundary layer code. Finally, the boundary-layer parameters are processed into a 3-D compressible boundary layer stability code (COSAL) to predict transition. The parametric study then consisted of four geometries which addressed the effects of sweep, and three angles of attack from zero to ten degrees to yield a total of 12 cases. The above process was substantially automated through a procedure that was developed by the work conducted under this study. This automation procedure then yields a 3-D graphical measure of the extent of laminar flow by predicting the transition location of laminar to turbulent flow
Impact of biobanks on research outcomes in rare diseases: a systematic review
BACKGROUND: Alleviating the burden of rare diseases requires research into new diagnostic and therapeutic strategies. We undertook a systematic review to identify and compare the impact of stand-alone registries, registries with biobanks, and rare disease biobanks on research outcomes in rare diseases.
METHODS: A systematic review and meta-aggregation was conducted using the preferred reporting items for systematic reviews and meta-analyses (the PRISMA statement). English language publications were sourced from PubMed, Medline, Scopus, and Web of Science. Original research papers that reported clinical, epidemiological, basic or translational research findings derived from data contained in stand-alone registries, registries with biobanks, and rare disease biobanks were considered. Articles selected for inclusion were assessed using the critical appraisal instruments by JBI-QARI. Each article was read in its entirety and findings were extracted using the online data extraction software from JBI-QARI.
RESULTS: Thirty studies including 28 rare disease resources were included in the review. Of those, 14 registries were not associated to biobank infrastructure, 9 registries were associated with biobank infrastructure, and 6 were rare disease biobank resources. Stand-alone registries had the capacity to uncover the natural history of disease and contributed to evidence-based practice. When annexed to biobank infrastructure, registries could also identify and validate biomarkers, uncover novel genes, elucidate pathogenesis at the Omics level, and develop new therapeutic strategies. Rare disease biobanks in this review had similar capacity for biological investigations, but in addition, had far greater sample numbers and higher quality laboratory techniques for quality assurance processes.
DISCUSSION: We examined the research outcomes of three specific populations: stand-alone registries, registries with biobanks, and stand-alone rare disease biobanks and demonstrated that there are key differences among these resources. These differences are a function of the resources\u27 design, aims, and objectives, with each resource having a distinctive and important role in contributing to the body of knowledge for rare disease research. Whilst stand-alone registries had the capacity to uncover the natural history of disease, develop best practice, replace clinical trials, and improve patient outcomes, they were limited in their capacity to conduct basic research. The role of basic research in rare disease research is vital; scientists must first understand the pathways of disease before they can develop appropriate interventions. Rare disease biobanks, on the other hand (particularly larger biobanks), had the key infrastructure required to conduct basic research, making novel Omics discoveries, identify and validate biomarkers, uncover novel genes, and develop new therapeutic strategies. However, these stand-alone rare disease biobanks did not collect comprehensive data or impact on clinical observations like a rare disease registry. Rare disease research is important not only for rare diseases, but also for also common diseases. For example, research of low-density lipoprotein (LDL)-receptors in the rare disease known as familial hypercholesterolemia led to the discovery of statins, a drug therapy that is now used routinely to prevent heart disease.
CONCLUSIONS: Rare diseases are still under-researched worldwide. This review made the important observation that registries with biobanks had the function of both stand-alone registries (the capacity to collect comprehensive clinical and epidemiological data) and stand-alone rare disease biobanks (the ability to contribute to Omics research). We found registries with biobanks offer a unique, practical, cost-effective, and impactful solution for rare disease research. Linkage of stand-alone registries to rare disease biobanks will provide the appropriate resources required for the effective translation of basic research into clinical practice. Furthermore, facilitators such as collaboration, engagement, blended recruitment, pro-active marketing, broad consent, and virtual biobank online catalogues will, if utilised, add to the success of these resources. These important observations can serve to direct future rare diseases research efforts, ultimately improve patient outcomes and alleviate the significant burden associated with rare disease for clinicians, hospitals, society, and most importantly, the patients and their families
Mixed-Reality Information Kit for Exploration (MIKE)
MIKE, short for Mixed-reality Information Kit for Exploration, is a virtual reality interface designed to enable an astronaut to conduct a successful, scientifically relevant EVA on the lunar surface. MIKE is a new system, being built from the ground-up, using lessons learned from its predecessor, ALEXEI. ALEXEI, the Augmented Lunar Exploration and Extravehicular Interface, previously developed by the Embry-Riddle SUIT Lab, now ASTRA Lab, was iteratively developed since the fall of 2019, having been presented in the NASA SUITS 2020, 2021, and 2022 Challenges [1, 2], and was a testbed for many features that may be utilized by astronauts during the Artemis missions. However, as these missions approach closer and the industry’s attention expands to Mars, several fundamental assumptions that underlaid ALEXEI have changed. Where ALEXEI assumed EVA hardware integration was out of scope, MIKE will be used to research how augmented reality (AR) systems can be implemented and controlled within EVA scenarios. Furthermore, while ALEXEI focused entirely on innovating and validating individual software features to be interacted with by a lone astronaut, MIKE will expand on these features to integrate into a larger EVA system, including multiple astronauts, a Local Mission Control Center (LMCC), and rover assistants. The primary goal for MIKE’s development within the 2024 NASA SUITS Challenge will be to provide insights into AR control schemes during EVA, while integrating within an analog Martian exploration system that will include LMCC and rover partner systems, and will guide an astronaut through egress, Martian navigation, airlock interaction, equipment repairs, science sampling, and final ingress as outlined in the 2024 NASA SUITS Mission Description [3]. MIKE is designed to be displayed on the Magic Leap 2 headset and will provide mission critical information in an unobtrusive manner, avoiding information overload while ensuring detailed information is available in an ergonomic way
- …