531 research outputs found

    Standard Model False Vacuum Inflation: Correlating the Tensor-to-Scalar Ratio to the Top Quark and Higgs Boson masses

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    For a narrow band of values of the top quark and Higgs boson masses, the Standard Model Higgs potential develops a false minimum at energies of about 101610^{16} GeV, where primordial Inflation could have started in a cold metastable state. A graceful exit to a radiation-dominated era is provided, e.g., by scalar-tensor gravity models. We pointed out that if Inflation happened in this false minimum, the Higgs boson mass has to be in the range 126.0±3.5126.0 \pm 3.5 GeV, where ATLAS and CMS subsequently reported excesses of events. Here we show that for these values of the Higgs boson mass, the inflationary gravitational wave background has be discovered with a tensor-to-scalar ratio at hand of future experiments. We suggest that combining cosmological observations with measurements of the top quark and Higgs boson masses represents a further test of the hypothesis that the Standard Model false minimum was the source of Inflation in the Universe.Comment: v1: 4 pages, 2 figures; v2: 5 pages, 2 figures, improvements in the text; v3: 5 pages, 2 figures, minor improvements in the text, matches PRL versio

    AC losses reduction in Hairpin Windings produced via Additive Manufacturing

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    One of the key challenges of hairpin windings is the reduction of their high losses at high-frequency operations. Hairpin layouts comprising conductors with variable cross sections have proven good loss performance in previous studies. However, they come at the cost of significant manufacturing complications. The aim of this work is to design hairpin layouts featuring reduced losses compared to classical configurations, exploiting the flexibility enabled by additive manufacturing. In this context, the choice of a proper material with relatively high conductivity and low ecological impact plays an important role. Hence, this article first presents an overview of materials that can be used for the winding additive manufacturing, aiming to select the most suitable one for the application at hand. Then, the loss performance is evaluated and compared against classical copper hairpins. The results demonstrate that opportunely selected alloys featuring asymmetric configurations can compete against classical hairpin windings. © 20XX IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis paper reflects only the author's view. JU is not responsible for any use that may be made of the information it contains

    "Swiss-Cheese" Inhomogeneous Cosmology & the Dark Energy Problem

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    We study an exact swiss-cheese model of the Universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We find negligible integrated effect, suppressed by (L/R_{H})^3 (where L is the size of one patch, and R_{H} is the Hubble radius), both perturbatively and non-perturbatively. We disentangle this effect from the Doppler term (which is much larger and has been used recently \cite{BMN} to try to fit the SN curve without dark energy) by making contact with cosmological perturbation theory.Comment: 35 pages, 6 figure

    Light Propagation and Large-Scale Inhomogeneities

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    We consider the effect on the propagation of light of inhomogeneities with sizes of order 10 Mpc or larger. The Universe is approximated through a variation of the Swiss-cheese model. The spherical inhomogeneities are void-like, with central underdensities surrounded by compensating overdense shells. We study the propagation of light in this background, assuming that the source and the observer occupy random positions, so that each beam travels through several inhomogeneities at random angles. The distribution of luminosity distances for sources with the same redshift is asymmetric, with a peak at a value larger than the average one. The width of the distribution and the location of the maximum increase with increasing redshift and length scale of the inhomogeneities. We compute the induced dispersion and bias on cosmological parameters derived from the supernova data. They are too small to explain the perceived acceleration without dark energy, even when the length scale of the inhomogeneities is comparable to the horizon distance. Moreover, the dispersion and bias induced by gravitational lensing at the scales of galaxies or clusters of galaxies are larger by at least an order of magnitude.Comment: 27 pages, 9 figures, revised version to appear in JCAP, analytical estimate included, typos correcte

    Clinical Support through Telemedicine in Heart Failure Outpatients during the COVID-19 Pandemic Period: Results of a 12-Months Follow Up

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    Background: Heart failure (HF) patients are predisposed to recurrences and disease destabilizations, especially during the COVID-19 outbreak period. In this scenario, telemedicine could be a proper way to ensure continuous care. The purpose of the study was to compare two modalities of HF outpatients’ follow up, the traditional in-person visits and telephone consultations, during the COVID-19 pandemic period in Italy. Methods: We conducted an observational study on consecutive HF outpatients. The follow up period was 12 months, starting from the beginning of the COVID-19 Italy lockdown. According to the follow up modality, and after the propensity matching score, patients were divided into two groups: those in G1 (n = 92) were managed with traditional in-person visits and those in G2 (n = 92) were managed with telephone consultation. Major adverse cardiovascular events (MACE) were the primary endpoints. Secondary endpoints were overall mortality, cardiovascular death, cardiovascular hospitalization, and hospitalization due to HF. Results: No significant differences between G1 and G2 have been observed regarding MACE (p = 0.65), cardiovascular death (p = 0.39), overall mortality (p = 0.85), hospitalization due to acute HF (p = 0.07), and cardiovascular hospitalization (p = 0.4). Survival analysis performed by the Kaplan–Meier method also did not show significant differences between G1 and G2. Conclusions: Telephone consultations represented a valid option to manage HF outpatients during COVID-19 pandemic, comparable to traditional in-person visits

    Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics

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    We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gr\"obner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular designs. For the purpose of analysis of data from fractional factorial designs, the techniques of Markov bases allow us to handle discrete observations. Thus the approach of computational algebraic statistics greatly enlarges the scope of fractional factorial designs.Comment: 16 page

    Clinicopathological Correlates in a PRNP P102L Mutation Carrier with Rapidly Progressing Parkinsonism-dystonia

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    Parkinsonism-dystonia is rare in carriers of PRNP P102L mutation. Severity and distribution of prion protein (PrP) deposition may influence the clinical presentation. We present such clinic-pathological correlation in a 56-year-old male with a PRNP P102L mutation associated with a phenotype characterized by rapidly progressing parkinsonism-dystonia. The patient was studied clinically (videotaped exams, brain MRIs); molecular genetically (gene sequence analysis); and neuropathologically (histology, immunohistochemistry) during his 7-month disease course. The patient had parkinsonism, apraxia, aphasia, and dystonia, which progressed rapidly. Molecular genetic analysis revealed PRNP P102L mutation carrier status. Brain MRIs revealed progressive global volume loss and T2/FLAIR hyperintensity in neocortex and basal ganglia. Postmortem examination showed neuronal loss, gliosis, spongiform changes, and PrP deposition in the striatum. PrP immunohistochemistry revealed widespread severe PrP deposition in the thalamus and cerebellar cortex. Based on the neuropathological and molecular-genetic analysis, the rapidly progressing parkinsonism-dystonia correlated with nigrostriatal, thalamic, and cerebellar pathology

    Cosmic Microwave Background, Accelerating Universe and Inhomogeneous Cosmology

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    We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous equations lead to luminosity distance and Hubble constant formulas that depend on the location of the observer. For a general inhomogeneous solution, it is possible for the deceleration parameter to differ significantly from the FLRW result. The deceleration parameter q0q_0 can be interpreted as q0>0q_0 > 0 (q0=1/2q_0=1/2 for a flat matter dominated universe) in a FLRW universe and be q0<0q_0 < 0 as inferred from the inhomogeneous enhancement that is embedded in a FLRW universe. A spatial volume averaging of local regions in the backward light cone has to be performed for the inhomogeneous solution at late times to decide whether the decelerating parameter qq can be negative for a positive energy condition. The CMB temperature fluctuations across the sky can be unevenly distributed in the northern and southern hemispheres in the inhomogeneous matter dominated solution, in agreement with the analysis of the WMAP power spectrum data by several authors. The model can possibly explain the anomalous alignment of the quadrupole and octopole moments observed in the WMAP data.Comment: 20 pages, no figures, LaTex file. Equations and typos corrected and references added. Additional material and some conclusions changed. Final published versio

    Effect of trikatu pretreatment on the pharmacokinetics of pefloxacin administered orally in mountain Gaddi goats

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    The pharmacokinetics of orally administered pefloxacin were studied to evaluate the bio-enhancing effect of the herbal bio-enhancer, trikatu, in mountain Gaddi goats (n = 6). The findings of the study revealed a decreased plasma concentration (p > 0.05) of pefloxacin following trikatu administration during the absorption phase (10, 15, 20 min post pefloxacin administration). In contrast, the plasma concentrations of pefloxacin were significantly higher at 4, 6, 8 and 12 h (during the elimination phase) of the pefloxacin administration. The findings of the investigation revealed higher values for the area under the curve, the area under the first moment of the plasma drug concentration time curve, the mean residential time, the total duration of pharmacological action and bioavailability. Trikatu treatment, however, significantly reduced the elimination half life (t1/2β) and zero time intercept of the elimination phase. The apparent volume of distribution based on the total area under the plasma drug concentration curve [(Vd(area)] and the apparent volume of distribution based on the zero time plasma concentration intercept of the elimination phase [Vd(B)] were significantly higher in trikatu treated animals indicating a better penetration of the drug. Based on the MIC of 0.8 µg/ml of pefloxacin, a priming dose of 6.0 mg/kg and a maintenance dose of 2.21 mg/kg is required to be administered at 8 h intervals. For practical purposes in goats this would mean a priming dose of 6 mg/kg and a maintenance dose of 2 mg/kg given by the oral route, to be repeated at 8 h intervals

    Averaging anisotropic cosmologies

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    We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of anisotropic pressure-free models. Adopting the Buchert scheme, we recast the averaged scalar equations in Bianchi-type form and close the standard system by introducing a propagation formula for the average shear magnitude. We then investigate the evolution of anisotropic average vacuum models and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. The presence of nonzero average shear in our equations also allows us to examine the constraints that a phase of backreaction-driven accelerated expansion might put on the anisotropy of the averaged domain. We close by assessing the status of these and other attempts to define and calculate `average' spacetime behaviour in general relativity.Comment: revised version, to appear in CQ
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