1,599 research outputs found

    Constraining decaying dark energy density models with the CMB temperature-redshift relation

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    We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as ρx(1+z)m\rho_x \propto (1+z)^{m}, z being the redshift. These models lead to the creation/disruption of matter and radiation, which affect the cosmic evolution of both matter and radiation components in the Universe. In particular, we have studied the temperature-redshift relation of radiation, which has been constrained using a recent collection of cosmic microwave background (CMB) temperature measurements up to z3z \sim 3. We find that, within the uncertainties, the model is indistinguishable from a cosmological constant which does not exchange any particles with other components. Future observations, in particular measurements of CMB temperature at large redshift, will allow to give firmer bounds on the effective equation of state parameter weffw_{eff} for such types of dark energy models.Comment: 9 pages, 1 figure, to appear in the Proceedings of the 3rd Italian-Pakistani Workshop on Relativistic Astrophysics, Lecce 20-22 June 2011, published in Journal of Physics: Conference Series (JPCS

    High-resolution tracking in a GEM-Emulsion detector

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    SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the CERN SPS aiming at the observation of long lived particles very weakly coupled with ordinary matter mostly produced in the decay of charmed hadrons. The beam dump facility of SHiP is also a copious factory of neutrinos of all three kinds and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus. The neutrino detector exploits the Emulsion Cloud Chamber technique with a modular structure, alternating walls of target units and planes of electronic detectors providing the time stamp to the event. GEM detectors are one of the possible choices for this task. This paper reports the results of the first exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the emulsion detector, the position resolution of the GEM chamber as a function of the particle inclination was evaluated in two configurations, with and without the magnetic fiel

    A double-ended queue with catastrophes and repairs, and a jump-diffusion approximation

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    Consider a system performing a continuous-time random walk on the integers, subject to catastrophes occurring at constant rate, and followed by exponentially-distributed repair times. After any repair the system starts anew from state zero. We study both the transient and steady-state probability laws of the stochastic process that describes the state of the system. We then derive a heavy-traffic approximation to the model that yields a jump-diffusion process. The latter is equivalent to a Wiener process subject to randomly occurring jumps, whose probability law is obtained. The goodness of the approximation is finally discussed.Comment: 18 pages, 5 figures, paper accepted by "Methodology and Computing in Applied Probability", the final publication is available at http://www.springerlink.co

    The Continuous Motion Technique for a New Generation of Scanning Systems

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    In the present paper we report the development of the Continuous Motion scanning technique and its implementation for a new generation of scanning systems. The same hardware setup has demonstrated a significant boost in the scanning speed, reaching 190 cm2/h. The implementation of the Continuous Motion technique in the LASSO framework, as well as a number of new corrections introduced are described in details. The performance of the system, the results of an efficiency measurement and potential applications of the technique are discussed

    Macrophage-polarizing stimuli differentially modulate the inflammatory profile induced by the secreted phospholipase A2 group IA in human lung macrophages

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    In this study we investigated the effects of snake venom Group IA secreted phospholipase A2 (svGIA) on the release of inflammatory and angiogenic mediators from human lung macrophages (HLMs). HLMs were incubated with lipopolysaccharide (LPS) or svGIA with or without macrophage-polarizing stimuli (IL-4, IL-10, IFN-γ or the adenosine analogue NECA). M2-polarizing cytokines (IL-4 and IL-10) inhibited TNF-α, IL-6, IL-12, IL-1β, CXCL8 and CCL1 release induced by both LPS and svGIA. IL-4 inhibited also the release of IL-10. IFN-γ reduced IL-10 and IL-12 and increased CCL1 release by both the LPS and svGIA-stimulated HLMs, conversely IFN-γ reduced IL-1β only by svGIA-stimulated HLMs. In addition, IFNγ promoted TNF-α and IL-6 release from svGIA-stimulated HLMs to a greater extent than LPS. NECA inhibited TNF-α and IL-12 but promoted IL-10 release from LPS-stimulated HLMs according to the well-known effect of adenosine in down-regulating M1 activation. By contrast NECA reduced TNF-α, IL-10, CCL1 and IL-1β release from svGIA-activated HLM. IL-10 and NECA increased both LPS- and svGIA-induced vascular endothelial growth factor A (VEGF-A) release. By contrast, IL-10 reduced angiopoietin-1 (ANGPT1) production from activated HLMs. IFN-γ and IL-4 reduced VEGF-A and ANGPT1 release from both LPS- and svGIA-activated HLMs. Moreover, IL-10 inhibited LPS-induced ANGPT2 production. In conclusion, we demonstrated a fine-tuning modulation of svGIA-activated HLMs differentially exerted by the classical macrophage-polarizing cytokines

    Can miRNAs be useful biomarkers in improving prognostic stratification in endometrial cancer patients? An update review

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    Endometrial cancer (EC) is the most common gynecological cancer, with annual incidence rates in Western countries ranging between 15 and 25 per 100 000 women. About 15% to 20% of patients with EC have high-risk disease and follow an aggressive clinical course. Unfortunately, the assessment of histologic parameters is poorly reproducible and conventional clinicopathological and molecular features do not reliably predict either the patient's response to the available treatments or the definition of personalized therapeutic approaches. In this context, the identification of novel diagnostic and prognostic biomarkers, which can be integrated in the current classification schemes, represents an unmet clinical need and an important challenge. miRNAs are key players in cancer by regulating the expression of specific target genes. Their role in EC, in association with clinical and prognostic tumor biomarkers, has been investigated but, so far, with little consensus among the studies. The present review aims to describe the recent advances in miRNAs research in EC taking into consideration the current classification schemes and to highlight the most promising miRNAs. Finally, a perspective point of view sheds light on the challenges ahead in the landscape of EC

    Comparative efficacy and acceptability of psychological interventions for the treatment of adult outpatients with anorexia nervosa: a systematic review and network meta-analysis

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    Background: No consistent first-option psychological interventions for adult outpatients with anorexia nervosa emerges from guidelines. We aimed to compare stand-alone psychological interventions for adult outpatients with anorexia nervosa with a specific focus on body-mass index, eating disorder symptoms, and all-cause dropout rate. Methods: In this systematic review and network meta-analysis, we assessed randomised controlled trials about stand-alone pharmacological or non-pharmacological treatments of adult outpatients with anorexia nervosa, defined according to standardised criteria, with data for at least two timepoints relating to either body-mass index or global eating disorder psychopathology. We searched Cochrane CENTRAL, CINAHL, MEDLINE, and PsychINFO for published and unpublished literature from inception until March 20, 2020. The primary outcomes were the change in body mass index and clinical symptoms, and the secondary outcome was all-cause dropout rate, which were all assessed for treatment as usual, cognitive behavioural therapy (CBT), Maudsley anorexia treatment for adults, family-based treatment, psychodynamic-oriented psychotherapies, a form of CBT targeting compulsive exercise, and cognitive remediation therapy followed by CBT. Global and local inconsistencies for the network meta-analysis were measured, and CINeMA was used to assess the confidence in evidence for primary outcomes. The protocol is registered in PROSPERO (CRD42017064429). Findings: Of 14 003 studies assessed for their title and abstract, 16 (0·1%) randomised controlled trials for psychological treatments were included in the systematic review, of which 13 (0·1%) contributed to the network meta-analysis, with 1047 patients in total (of whom 1020 [97·4%] were female). None of the interventions outperformed treatment as usual in our primary outcomes, but the all-cause dropout rate was lower for CBT than for psychodynamic-oriented psychotherapies (OR 0·54, 95% CI 0·31–0·93). Heterogeneity or inconsistency emerged only for a few comparisons. Confidence in the evidence was low to very low. Interpretation: Compared with treatment as usual, specific psychological treatments for adult outpatients with anorexia nervosa can be associated with modest improvements in terms of clinical course and quality of life, but no reliable evidence supports clear superiority or inferiority of the specific treatments that are recommended by clinical guidelines internationally. Our analysis is based on the best data from existing clinical studies, but these findings should not be seen as definitive or universally applicable. There is an urgent need to fund new research to develop and improve therapies for adults with anorexia nervosa. Meanwhile, to better understand the effects of available treatments, participant-level data should be made freely accessible to researchers to eventually identify whether specific subgroups of patients are more likely to respond to specific treatments. Funding: Flinders University, National Institute for Health Research Oxford Health Biomedical Research Centre

    Limits on decaying dark energy density models from the CMB temperature-redshift relation

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    The nature of the dark energy is still a mystery and several models have been proposed to explain it. Here we consider a phenomenological model for dark energy decay into photons and particles as proposed by Lima (J. Lima, Phys. Rev. D 54, 2571 (1996)). He studied the thermodynamic aspects of decaying dark energy models in particular in the case of a continuous photon creation and/or disruption. Following his approach, we derive a temperature redshift relation for the CMB which depends on the effective equation of state weffw_{eff} and on the "adiabatic index" γ\gamma. Comparing our relation with the data on the CMB temperature as a function of the redshift obtained from Sunyaev-Zel'dovich observations and at higher redshift from quasar absorption line spectra, we find weff=0.97±0.034w_{eff}=-0.97 \pm 0.034, adopting for the adiabatic index γ=4/3\gamma=4/3, in good agreement with current estimates and still compatible with weff=1w_{eff}=-1, implying that the dark energy content being constant in time.Comment: 8 pages, 1 figur

    Adipose Tissue Plasticity During Catch-Up Fat Driven by Thrifty Metabolism: Relevance for Muscle-Adipose Glucose Redistribution During Catch-Up Growth

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    OBJECTIVE: Catch-up growth, a risk factor for later type 2 diabetes, is characterized by hyperinsulinemia, accelerated body-fat recovery (catch-up fat), and enhanced glucose utilization in adipose tissue. Our objective was to characterize the determinants of enhanced glucose utilization in adipose tissue during catch-up fat. RESEARCH DESIGN AND METHODS: White adipose tissue morphometry, lipogenic capacity, fatty acid composition, insulin signaling, in vivo glucose homeostasis, and insulinemic response to glucose were assessed in a rat model of semistarvation-refeeding. This model is characterized by glucose redistribution from skeletal muscle to adipose tissue during catch-up fat that results solely from suppressed thermogenesis (i.e., without hyperphagia). RESULTS: Adipose tissue recovery during the dynamic phase of catch-up fat is accompanied by increased adipocyte number with smaller diameter, increased expression of genes for adipogenesis and de novo lipogenesis, increased fatty acid synthase activity, increased proportion of saturated fatty acids in triglyceride (storage) fraction but not in phospholipid (membrane) fraction, and no impairment in insulin signaling. Furthermore, it is shown that hyperinsulinemia and enhanced adipose tissue de novo lipogenesis occur concomitantly and are very early events in catch-up fat. CONCLUSIONS: These findings suggest that increased adipose tissue insulin stimulation and consequential increase in intracellular glucose flux play an important role in initiating catch-up fat. Once activated, the machinery for lipogenesis and adipogenesis contribute to sustain an increased insulin-stimulated glucose flux toward fat storage. Such adipose tissue plasticity could play an active role in the thrifty metabolism that underlies glucose redistribution from skeletal muscle to adipose tissue
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