126 research outputs found
Robust implications on Dark Matter from the first FERMI sky gamma map
No full textWe derive robust model-independent bounds on DM annihilations and decays from the first year of FERMI gamma-ray observations of the whole sky. These bounds only have a mild dependence on the DM density profile and allow the following DM interpretations of the PAMELA and FERMI electron/positron excesses: primary channels mu+ mu-, mu+ mu-mu+mu- or e+ e- e+ e-. An isothermal-like density profile is needed for annihilating DM. In all such cases, FERMI gamma spectra must contain a significant DM component, that may be probed in the future.We derive robust model-independent bounds on DM annihilations and decays from the first year of FERMI gamma-ray observations of the whole sky. These bounds only have a mild dependence on the DM density profile and allow the following DM interpretations of the PAMELA and FERMI electron/positron excesses: primary channels mu+ mu-, mu+ mu-mu+mu- or e+ e- e+ e-. An isothermal-like density profile is needed for annihilating DM. In all such cases, FERMI gamma spectra must contain a significant DM component, that may be probed in the future
Monojet versus the rest of the world I: t-channel models
No full textMonojet searches using Effective Field Theory (EFT) operators are usually interpreted as a robust and model independent constraint on direct detection (DD) scattering cross-sections. At the same time, a mediator particle must be present to produce the dark matter (DM) at the LHC. This mediator particle may be produced on shell, so that direct searches for the mediating particle can constrain the effective operator being applied to monojet constraints. In this first paper, we do a case study on t-channel models in monojet searches, where the (Standard Model singlet) DM is pair produced via a t-channel mediating particle, whose supersymmetric analogue is the squark. We compare monojet constraints to direct constraints on single or pair production of the mediator from multi-jets plus missing energy searches and we identify the regions where the latter dominate over the former. We show that computing bounds using supersymmetric simplified models and in the narrow width approximation, as done in previous work in the literature, misses important quantitative effects. We perform a full event simulation and statistical analysis, and we compute the effects of both on- and off-shell production of the mediating particle, showing that for both the monojet and multi-jets plus missing energy searches, previously derived bounds provided more conservative bounds than what can be extracted by including all relevant processes in the simulation. Monojets and searches for super-symmetry (SUSY) provide comparable bounds on a wide range of the parameter space, with SUSY searches usually providing stronger bounds, except in the regions where the DM particle and the mediator are very mass degenerate. The EFT approximation rarely is able to reproduce the actual limits. In a second paper to follow, we consider the case of s-channel mediators
Mono-X versus direct searches: simplified models for dark matter at the LHC
No full textWe consider simplified models for dark matter (DM) at the LHC, focused on mono-Higgs, -Z or -b produced in the final state. Our primary purpose is to study the LHC reach of a relatively complete set of simplified models for these final states, while comparing the reach of the mono-X DM search against direct searches for the mediating particle. We find that direct searches for the mediating particle, whether in di-jets, jets+[InlineMediaObject not available: see fulltext.], multi-b+[InlineMediaObject not available: see fulltext.], or di-boson+[InlineMediaObject not available: see fulltext.], are usually stronger. We draw attention to the cases that the mono-X search is strongest, which include regions of parameter space in inelastic DM, two Higgs doublet, and squark mediated production models with a compressed spectrum
Ghosts in massive gravity
No full textIn the context of Lorentz-invariant massive gravity we show that classical solutions around heavy sources are plagued by ghost instabilities. The ghost shows up in the effective field theory at huge distances from the source, much bigger than the Vainshtein radius. Its presence is independent of the choice of the non-linear terms added to the Fierz-Pauli lagrangian. At the Vainshtein radius the mass of the ghost is of order of the inverse radius, so that the theory cannot be trusted inside this region, not even at the classical level
La distribuzione dei radionuclidi nell'ambiente marino antistante la Centrale di Latina
No full textedito da Direzione Centrale Relazioni dell' ENEA, anche come RT/BIO (81) 2
Eating habits in elderly diabetic subjects: Assessment in the InCHIANTI Study
No full textBackground and aims: Nutritional therapy is a cornerstone of the treatment of type 2 diabetes. The aim of this study was to assess differences in dietary habits between subjects with and without known type 2 diabetes. Methods and Results: In a sample of 1242 predominantly elderly subjects enrolled in the InCHIANTI study, total energy and macronutrient intake was assessed cross-sectionally using the EPIC self-reported questionnaire. Results were compared in subjects with (N = 109) and without known diabetes, and differences were adjusted for age, sex, and reported comorbidities. Subjects with known diabetes reported a significantly lower (p < 0.001) total energy and soluble carbohydrate intake in comparison with the rest of the sample (1793 +/- 481 vs 2040 +/- 624 kCal/day, and 66.9 +/- 22.3 vs. 93.5 +/- 34.9 g/day, respectively). Conversely, consumption of total and saturated fats, dietary fibres and proteins was not significantly different. Conclusion: Known diabetes is associated with a reduction of soluble carbohydrate consumption and total energy intake without any further modification of dietary habits. These data suggest that the diagnosis of diabetes could induce some changes in nutritional style. However, corrections in dietary habits do not appear to be consistent with current guidelines and recommendations. (C) 2007 Elsevier B.V. All rights reserved
Distribuzione dei radionuclidi nell'ambiente marino antistante la Centrale del Garigliano
No full textBresci
Sustainable Pd-Catalyzed Direct Arylation of Thienyl Derivatives with (Hetero)aromatic Bromides under Air in Deep Eutectic Solvents
No full textAn optimized protocol for the Pd-catalyzed direct arylation of 3,4-ethylenedioxythiophene (EDOT) and other substituted thiophenes with (hetero)aromatic bromides in a deep eutectic solvent made of a mixture of choline chloride/glycerol (1:2) is presented. The coupling reactions have been successfully run under air, in nonanhydrous conditions, using PdCl2 as a palladium source, with a catalyst loading as low as 1 mol %. The adjustment of each reaction component allowed finding robust conditions for the introduction of both electron-poor and electron-rich (hetero)aryl bromides with moderate-to-high yields. The sustainability of the protocol was established through calculations of green metrics, such as Eco-scale and E-factor, and compared with the literature, when possible. Remarkably, such procedure can be successfully applied for the simple preparation of conjugated organic compounds with potential applications in optoelectronics, as we have shown, by obtaining two molecules previously reported as a hole transport material for perovskite solar cells and the final intermediate of a photosensitizer for dye-sensitized solar cells
Coenzyme Q10 protects retinal cells from apoptosis induced by radiation in vitro and in vivo
No full texthe key pathogenetic event of many retinopathies is apoptosis of retinal cells. Our previous studies have demonstrated that Coenzyme Q10 (CoQ10) prevents apoptosis of corneal keratocytes both in vitro and in vivo, by virtue of its ability to inhibit mitochondrial depolarization, independently of its free radical scavenger role. The aim of this study was to evaluate whether CoQ10 can protect cultured retinal cells and the retinas of rats from radiation-induced apoptosis, if instilled as eye drops in the cornea. In vitro experiments were carried out on cultured ARPE-19 or RGC-5 cells pretreated with CoQ10 before eliciting apoptosis by UV- and γ-radiation, chemical hypoxia (Antimycin A) and serum starvation. Cell viability was evaluated by light microscopy and fluorescence activated cell sorting analysis. Apoptotic events were scored by time-lapse videomicroscopy. Mitochondrial permeability transition was evaluated by JC-1. The anti-apoptotic effectiveness of CoQ10 in retina was also evaluated by an in situ end-labeling assay in Wistar albino rats treated with CoQ10 eye drops prior to UV irradiation of the eye. CoQ10 substantially increased cell viability and lowered retinal cell apoptosis in response both to UV- and γ-radiation and to chemical hypoxia or serum starvation by inhibiting mitochondrion depolarization. In the rat, CoQ10, even when applied as eye drops on the cornea, protected all retina layers from UVR-induced apoptosis. The ability of CoQ10 to protect retinal cells from radiation-induced apoptosis following its instillation on the cornea suggests the possibility for CoQ10 eye drops to become a future therapeutic countermeasure for radiation-induced retinal lesions
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