1,387 research outputs found

    Estimating the Costs of Preventive Interventions

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    The goal of this article is to improve the practice and reporting of cost estimates of prevention programs. It reviews the steps in estimating the costs of an intervention and the principles that should guide estimation. We then review prior efforts to estimate intervention costs using a sample of well-known but diverse studies. Finally, we illustrate the principles with an example, the Family Bereavement Program. We conclude that example by discussing whether and how the costs of the intervention might differ when implemented in a real-world setting

    Natural Little Hierarchy from a Partially Goldstone Twin Higgs

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    We construct a simple theory in which the fine-tuning of the standard model is significantly reduced. Radiative corrections to the quadratic part of the scalar potential are constrained to be symmetric under a global U(4) x U(4)' symmetry due to a discrete Z_2 "twin" parity, while the quartic part does not possess this symmetry. As a consequence, when the global symmetry is broken the Higgs fields emerge as light pseudo-Goldstone bosons, but with sizable quartic self-interactions. This structure allows the cutoff scale, \Lambda, to be raised to the multi-TeV region without significant fine-tuning. In the minimal version of the theory, the amount of fine-tuning is about 15% for \Lambda = 5 TeV, while it is about 30% in an extended model. This provides a solution to the little hierarchy problem. In the minimal model, the "visible" particle content is exactly that of the two Higgs doublet standard model, while the extended model also contains extra vector-like fermions with masses ~(1-2)TeV. At the LHC, our minimal model may appear exactly as the two Higgs doublet standard model, and new physics responsible for cutting off the divergences of the Higgs mass-squared parameter may not be discovered. Several possible processes that may be used to discriminate our model from the simple two Higgs doublet model are discussed for the LHC and for a linear collider.Comment: 22 page

    A search of CO emission lines in blazars: the low molecular gas content of BL Lac objects compared to quasars

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    BL Lacertae (Lac) objects that are detected at very high energies (VHE) are of fundamental importance to study multiple astrophysical processes, including the physics of jets, the properties of the extragalactic background light and the strength of the intergalactic magnetic field. Unfortunately, since most blazars have featureless optical spectra that preclude a redshift determination, a substantial fraction of these VHE extragalactic sources cannot be used for cosmological studies. To assess whether molecular lines are a viable way to establish distances, we have undertaken a pilot programme at the Institut of MillimĂ©trique (IRAM) 30 m telescope to search for CO lines in three BL Lac objects with known redshifts. We report a positive detection of  M⊙ towards 1ES 1959+650, but due to the poor quality of the baseline, this value is affected by a large systematic uncertainty. For the remaining two sources, W Comae and RGB J0710+591, we derive 3σ upper limits at, respectively, and 1.6 × 109  M⊙, assuming a line width of 150 km s−1 and a standard conversion factor α = 4  M⊙ (K km s−1 pc2)−1. If these low molecular gas masses are typical for blazars, blind redshift searches in molecular lines are currently unfeasible. However, deep observations are still a promising way to obtain precise redshifts for sources whose approximate distances are known via indirect methods. Our observations further reveal a deficiency of molecular gas in BL Lac objects compared to quasars, suggesting that the host galaxies of these two types of active galactic nuclei (AGN) are not drawn from the same parent population. Future observations are needed to assess whether this discrepancy is statistically significant, but our pilot programme shows how studies of the interstellar medium in AGN can provide key information to explore the connection between the active nuclei and the host galaxie

    Axion-Higgs Unification

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    In theories with no fundamental scalars, one gauge group can become strong at a large scale Lambda and spontaneously break a global symmetry, producing the Higgs and the axion as composite pseudo-Nambu-Goldstone bosons. We show how KSVZ and DFSZ axion models can be naturally realised. The assumption Lambda around 10^{11} GeV is phenomenologically favoured because: a) The axion solves the QCD theta problem and provides the observed DM abundance; b) The observed Higgs mass is generated via RGE effects from a small Higgs quartic coupling at the compositeness scale, provided that the Higgs mass term is fine-tuned to be of electroweak size; c) Lepton, quark as well as neutrino masses can be obtained from four-fermion operators at the compositeness scale. d) The extra fermions can unify the gauge couplings.Comment: 19 pages. Refs. added and eq. 3.6 fixe

    Superposition Attack on OT Protocols

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    In this note, we study the security of oblivious transfer protocols in the presence of adversarial superposition queries. We define a security notion for the sender against a corrupted receiver that makes a superposition query. We present an oblivious transfer protocol that is secure against a quantum receiver restricted to a classical query but it is insecure when the receiver makes a quantum query

    Erectile dysfunction and quality of life in type 2 diabetic patients: a serious problem too often overlooked.

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    OBJECTIVE—Within the context of a large, nationwide outcomes research program in type 2 diabetes, we assess the prevalence of self-reported erectile dysfunction and evaluate its impact on quality of life. RESEARCH DESIGN AND METHODS—The study involved 1,460 patients enrolled by 114 diabetes outpatient clinics and 112 general practitioners. Patients were asked to complete a questionnaire investigating their ability to achieve and maintain an erection. Various aspects of quality of life were also assessed depressive using the following instruments: SF-36 Health Survey, diabetes health distress, psychological adaptation to diabetes, depressive symptoms (CES-D scale), and quality of sexual life. RESULTS—Overall, 34% of the patients reported frequent erectile problems, 24% reported occasional problems, and 42% reported no erectile problems. After adjusting for patient characteristics, erectile dysfunction was associated with higher levels of diabetes-specific health distress and worse psychological adaptation to diabetes, which were, in turn, related to worse metabolic control. Erectile problems were also associated with a dramatic increase in the prevalence of severe depressive symptoms, lower scores in the mental components of the SF-36, and a less satisfactory sexual life. A total of 63% of the patients reported that their physicians had never investigated their sexual problems. CONCLUSIONS—Erectile dysfunction is extremely common among type 2 diabetic patients and is associated with poorer quality of life, as measured with generic and diabetes-specific instruments. Despite their relevance, sexual problems are seldom investigated by general practitioners and specialists

    Quality of Care and Outcomes in Type 2 Diabetic Patients A comparison between general practice and diabetes clinics

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    OBJECTIVE—The role of general practice and diabetes clinics in the management of diabetes is still a matter of debate. Methodological flaws in previous studies may have led to inaccurate conclusions when comparing the care provided in these different settings. We compared the care provided to type 2 diabetic patients attending diabetes outpatient clinics (DOCs) or being treated by a general practitioner (GP) using appropriate statistical methods to adjust for patient case mix and physician-level clustering. RESEARCH DESIGN AND METHODS—We prospectively evaluated the process and intermediate outcome measures over 2 years in a sample of 3,437 patients recruited by 212 physicians with different specialties practicing in 125 DOCs and 103 general practice offices. Process measures included frequency of HbA1c, lipids, microalbuminuria, and serum creatinine measurements and frequency of foot and eye examinations. Outcome measures included HbA1c, blood pressure, and total and LDL cholesterol levels. RESULTS—Differences for most process measures were statistically significantly in favor of DOCs. The differences were more marked for patients who were always treated by the same physician within a DOC and if that physician had a specialty in diabetology. Less consistent differences in process measures were detected when patients followed by GPs were compared with those followed by physicians with a specialty other than diabetology. As for the outcomes considered, patients attending DOCs attained better total cholesterol levels, whereas no major differences emerged in terms of metabolic control and blood pressure levels between DOCs and GPs. Physicians' specialties were not independently related to patient outcomes. CONCLUSIONS—Being followed always by the same physician in a DOC, particularly if the physician had a specialty in diabetes, ensured better quality of care in terms of process measures. In the short term, care provided by DOCs was also associated with better intermediate outcome measures, such as total cholesterol levels

    A search of CO emission lines in blazars: the low molecular gas content of BL Lac objects compared to quasars

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    BL Lacertae (Lac) objects that are detected at very-high energies (VHE) are of fundamental importance to study multiple astrophysical processes, including the physics of jets, the properties of the extragalactic background light and the strength of the intergalactic magnetic field. Unfortunately, since most blazars have featureless optical spectra that preclude a redshift determination, a substantial fraction of these VHE extragalactic sources cannot be used for cosmological studies. To assess whether molecular lines are a viable way to establish distances, we have undertaken a pilot program at the IRAM 30m telescope to search for CO lines in three BL Lac objects with known redshifts. We report a positive detection of M_H2 ~ 3x10^8 Msun toward 1ES 1959+650, but due to the poor quality of the baseline, this value is affected by a large systematic uncertainty. For the remaining two sources, W Comae and RGB J0710+591, we derive 3sigma upper limits at, respectively, M_H2 < 8.0x10^8 Msun and M_H2 < 1.6x10^9 Msun, assuming a line width of 150 km/s and a standard conversion factor alpha=4 M_sun/(K km/s pc^2). If these low molecular gas masses are typical for blazars, blind redshift searches in molecular lines are currently unfeasible. However, deep observations are still a promising way to obtain precise redshifts for sources whose approximate distances are known via indirect methods. Our observations further reveal a deficiency of molecular gas in BL Lac objects compared to quasars, suggesting that the host galaxies of these two types of active galactic nuclei (AGN) are not drawn from the same parent population. Future observations are needed to assess whether this discrepancy is statistically significant, but our pilot program shows how studies of the interstellar medium in AGN can provide key information to explore the connection between the active nuclei and the host galaxies.Comment: 8 pages, 3 figures. MNRAS accepte

    Flux Stabilization in 6 Dimensions: D-terms and Loop Corrections

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    We analyse D-terms induced by gauge theory fluxes in the context of 6-dimensional supergravity models. On the one hand, this is arguably the simplest concrete setting in which the controversial idea of `D-term uplifts' can be investigated. On the other hand, it is a very plausible intermediate step on the way from a 10d string theory model to 4d phenomenology. Our specific results include the flux-induced one-loop correction to the scalar potential coming from charged hypermultiplets. Furthermore, we comment on the interplay of gauge theory fluxes and gaugino condensation in the present context, demonstrate explicitly how the D-term arises from the gauging of one of the compactification moduli, and briefly discuss further ingredients that may be required for the construction of a phenomenologically viable model. In particular, we show how the 6d dilaton and volume moduli can be simultaneously stabilized, in the spirit of KKLT, by the combination of an R symmetry twist, a gaugino condensate, and a flux-induced D-term.Comment: 24 pages, 1 figure v2:minor correction
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