858 research outputs found

    Tensors Mesons in AdS/QCD

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    We explore tensor mesons in AdS/QCD focusing on f2 (1270), the lightest spin-two resonance in QCD. We find that the f2 mass and the partial width for f2 -> gamma gamma are in very good agreement with data. In fact, the dimensionless ratio of these two quantities comes out within the current experimental bound. The result for this ratio depends only on Nc and Nf, and the quark and glueball content of the operator responsible for the f2; more importantly, it does not depend on chiral symmetry breaking and so is both independent of much of the arbitrariness of AdS/QCD and completely out of reach of chiral perturbation theory. For comparison, we also explore f2 -> pi pi, which because of its sensitivity to the UV corrections has much more uncertainty. We also calculate the masses of the higher spin resonances on the Regge trajectory of the f2, and find they compare favorably with experiment.Comment: 21 pages, 1 figure; Li's correcte

    Isotopic Composition of the Ogallala-high Plains Aquifer Andvadose Zone

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    AbstractThe Ogallala-High Plains aquifer is an important resource for irrigated agriculture in a semi-arid region of the United States. Steep declines in groundwater levels are putting increasing strain on the viability of the aquifer for irrigation, necessitating improved estimates of recharge rates and sources to the aquifer. This study uses a combined approach to obtain high resolution geochemical and isotopic composition of the vadose zone and aquifer pore fluids to better understand recharge dynamics to the aquifer. Significant differences between the shallow, intermediate and deep vadose zone and shallow and deep aquifer indicate modern precipitation is not providing a significant source of recharge to the aquifer across a large area (diffuse recharge). Rather, recharge to the aquifer is a result of either focused recharge or long-term, delayed drainage from the portion of the vadose zone which was saturated before irrigation development

    Stromal cells from the adipose tissue-derived stromal vascular fraction and culture expanded adipose tissue-derived stromal/stem cells: A joint statement of the International Federation for Adipose Therapeutics and Science (IFATS) and the International Society for Cellular Therapy (ISCT)

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    Adipose tissue is a rich and very convenient source of cells for regenerative medicine therapeutic approaches. However, a characterization of the population of adipose-derived stromal and stem cells (ASCs) with the greatest therapeutic potential remains unclear. Under the authority of International Federation of Adipose Therapeutics and International Society for Cellular Therapy, this paper sets out to establish minimal definitions of stromal cells both as uncultured stromal vascular fraction (SVF) and as an adherent stromal/stem cells population.Phenotypic and functional criteria for the identification of adipose-derived cells were drawn from the literature.In the SVF, cells are identified phenotypically by the following markers: CD45-CD235a-CD31-CD34+. Added value may be provided by both a viability marker and the following surface antigens: CD13, CD73, CD90 and CD105. The fibroblastoid colony-forming unit assay permits the evaluation of progenitor frequency in the SVF population. In culture, ASCs retain markers in common with other mesenchymal stromal/stem cells (MSCs), including CD90, CD73, CD105, and CD44 and remain negative for CD45 and CD31. They can be distinguished from bone-marrow-derived MSCs by their positivity for CD36 and negativity for CD106. The CFU-F assay is recommended to calculate population doublings capacity of ASCs. The adipocytic, chondroblastic and osteoblastic differentiation assays serve to complete the cell identification and potency assessment in conjunction with a quantitative evaluation of the differentiation either biochemically or by reverse transcription polymerase chain reaction.The goal of this paper is to provide initial guidance for the scientific community working with adipose-derived cells and to facilitate development of international standards based on reproducible parameters.Background aims: Adipose tissue is a rich and very convenient source of cells for regenerative medicine therapeutic approaches. However, a characterization of the population of adipose-derived stromal and stem cells (ASCs) with the greatest therapeutic potential remains unclear. Under the authority of International Federation of Adipose Therapeutics and International Society for Cellular Therapy, this paper sets out to establish minimal definitions of stromal cells both as uncultured stromal vascular fraction (SVF) and as an adherent stromal/stem cells population. Methods: Phenotypic and functional criteria for the identification of adipose-derived cells were drawn from the literature. Results: In the SVF, cells are identified phenotypically by the following markers: CD45-CD235a-CD31-CD34+. Added value may be provided by both a viability marker and the following surface antigens: CD13, CD73, CD90 and CD105. The fibroblastoid colony-forming unit assay permits the evaluation of progenitor frequency in the SVF population. In culture, ASCs retain markers in common with other mesenchymal stromal/stem cells (MSCs), including CD90, CD73, CD105, and CD44 and remain negative for CD45 and CD31. They can be distinguished from bone-marrow-derived MSCs by their positivity for CD36 and negativity for CD106. The CFU-F assay is recommended to calculate population doublings capacity of ASCs. The adipocytic, chondroblastic and osteoblastic differentiation assays serve to complete the cell identification and potency assessment in conjunction with a quantitative evaluation of the differentiation either biochemically or by reverse transcription polymerase chain reaction. Conclusions: The goal of this paper is to provide initial guidance for the scientific community working with adipose-derived cells and to facilitate development of international standards based on reproducible parameters. \ua9 2013, International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved

    Tools for Deconstructing Gauge Theories in AdS5

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    We employ analytical methods to study deconstruction of 5D gauge theories in the AdS5 background. We demonstrate that using the so-called q-Bessel functions allows a quantitative analysis of the deconstructed setup. Our study clarifies the relation of deconstruction with 5D warped theories.Comment: 30 pages; v2: several refinements, references adde

    Opportunities and Challenges to Emergency Department-Based HIV Testing Services and Self-Testing Programs: A Qualitative Study of Healthcare Providers and Patients in Kenya

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    BACKGROUND: Young people in Sub-Saharan Africa, especially males, have been insufficiently engaged through HIV Testing Services (HTS). In Kenya, younger persons are often treated in emergency departments (EDs) for injuries, an interaction where HTS and HIV self-testing (HIVST) can be leveraged. Data from stakeholders on ED-HTS and HIVST is lacking and needed to understand opportunities and barriers for HIV testing and care, and inform program implementation. METHODS: Between December 2021 and March 2022, 32 in-depth interviews (IDIs) were conducted with 16 male and 16 female patients who had been treated in the Kenyatta National Hospital (KNH) ED, half of whom had been HIV-tested. Six focus-group discussions (FGDs) were also conducted with 50 nurses, doctors, HIV testing counselors, and administrators working in the ED. All transcripts were double-coded and thematically analyzed using Dedoose software and a parallel inductive and deductive coding approach which allowed for capture of both a priori and emergent themes. RESULTS: Patients and providers agreed that ED-HTS are facilitated by friendly staff, patient education, high perceived HIV risk, and confidentiality. However, ED-HTS is limited by burdens on staff, resources, time, and space, as well as severity of patient injuries limiting ability to consent to or prioritize HIV testing. These limitations provide opportunities for ED-HIVST: particularly the ability to test at a comfortable time and place, especially when provided alongside sufficient HIV and testing education, contact with healthcare providers, and psychosocial support. Barriers for ED-HIVST where identified and as patients’ concerns about HIVST accuracy and mental health impacts of a positive test, as well providers’ identified barriers on their concerns for loss to follow up and inability to complete confirmatory testing. COM-B Model [Figure: see text] Application of the COM-B Model of Behavior Change to ED-HIVST Acceptability in Kenya CONCLUSION: ED stakeholders are receptive to HTS and HIVST, and patients desire the opportunity to use HIVST. Potential challenges—such as psychological effects of testing positive, worries about access to follow-up care, and confusion about how to self-administer testing, may be addressed through programming designed to promote education, access and ensure follow-up mechanisms. DISCLOSURES: All Authors: No reported disclosures

    Mass-Matching in Higgsless

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    Modern extra-dimensional Higgsless scenarios rely on a mass-matching between fermionic and bosonic KK resonances to evade constraints from precision electroweak measurements. After analyzing all of the Tevatron and LEP bounds on these so-called Cured Higgsless scenarios, we study their LHC signatures and explore how to identify the mass-matching mechanism, the key to their viability. We find singly and pair produced fermionic resonances show up as clean signals with 2 or 4 leptons and 2 hard jets, while neutral and charged bosonic resonances are visible in the dilepton and leptonic WZ channels, respectively. A measurement of the resonance masses from these channels shows the matching necessary to achieve S0S\simeq 0. Moreover, a large single production of KK-fermion resonances is a clear indication of compositeness of SM quarks. Discovery reach is below 10 fb1^{-1} of luminosity for resonances in the 700 GeV range.Comment: 28 pages, 18 figure

    Temporal Deconvolution study of Long and Short Gamma-Ray Burst Light curves

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    The light curves of Gamma-Ray Bursts (GRBs) are believed to result from internal shocks reflecting the activity of the GRB central engine. Their temporal deconvolution can reveal potential differences in the properties of the central engines in the two populations of GRBs which are believed to originate from the deaths of massive stars (long) and from mergers of compact objects (short). We present here the results of the temporal analysis of 42 GRBs detected with the Gamma-ray Burst Monitor onboard the Fermi Gamma-ray Space Telescope. We deconvolved the profiles into pulses, which we fit with lognormal functions. The distributions of the pulse shape parameters and intervals between neighboring pulses are distinct for both burst types and also fit with lognormal functions. We have studied the evolution of these parameters in different energy bands and found that they differ between long and short bursts. We discuss the implications of the differences in the temporal properties of long and short bursts within the framework of the internal shock model for GRB prompt emission.Comment: 38 pages, 11 figure

    Pediatric home mechanical ventilation: A Canadian Thoracic Society clinical practice guideline executive summary

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    Over the last 30 to 40 years, improvements in technology, as well as changing clinical practice regarding the appropriateness of long-term ventilation in patients with “non-curable” disorders, have resulted in increasing numbers of children surviving what were previously considered fatal conditions. This has come but at the expense of requiring ongoing, long-term prolonged mechanical ventilation (both invasive and noninvasive). Although there are many publications pertaining to specific aspects of home mechanical ventilation (HMV) in children, there are few comprehensive guidelines that bring together all of the current literature. In 2011 the Canadian Thoracic Society HMV Guideline Committee published a review of the available English literature on topics related to HMV in adults, and completed a detailed guideline that will help standardize and improve the assessment and management of individuals requiring noninvasive or invasive HMV. This current document is intended to be a companion to the 2011 guidelines, concentrating on the issues that are either unique to children on HMV (individuals under 18 years of age), or where common pediatric practice diverges significantly from that employed in adults on long-term home ventilation. As with the adult guidelines,1 this document provides a disease-specific review of illnesses associated with the necessity for long-term ventilation in children, including children with chronic lung disease, spinal muscle atrophy, muscular dystrophies, kyphoscoliosis, obesity hypoventilation syndrome, and central hypoventilation syndromes. It also covers important common themes such as airway clearance, the ethics of initiation of long-term ventilation in individuals unable to give consent, the process of transition to home and to adult centers, and the impact, both financial, as well as social, that this may have on the child\u27s families and caregivers. The guidelines have been extensively reviewed by international experts, allied health professionals and target audiences. They will be updated on a regular basis to incorporate any new information

    Two-loop Corrections to the B to pi Form Factor from QCD Sum Rules on the Light-Cone and |V(ub)|

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    We calculate the leading-twist O(alphas^2 beta0) corrections to the B to pi transition form factor f+(0) in light-cone sum rules. We find that, as expected, there is a cancellation between the O(alphas^2 beta0) corrections to fB f+(0) and the large corresponding corrections to fB, calculated in QCD sum rules. This suggests the insensitivity of the form factors calculated in the light-cone sum rules approach to this source of radiative corrections. We further obtain an improved determination of the CKM matrix element |V(ub)|, using latest results from BaBar and Belle for f+(0)|V(ub)|.Comment: 18 pages, 3 figure
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