154 research outputs found

    Low Energy Neutrino Measurements

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    Low Energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND experiments as well as from upcoming (SNO+) and planned (LENA) experiments. Scintillator neutrino detectors are also powerful antineutrino detectors such as those emitted by the Earth crust and mantle. First measurements of geo-neutrinos have occurred and can bring fundamental contribution in understanding the geophysics of the planet.Comment: 18 pages, 36 figures, proceedings of XXV Lepton Photon, 22 to 27 August 2011, published on 2012-10-0

    Seasonal modulation in the Borexino cosmic muon signal

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    Borexino is an organic liquid scintillator detector located in the underground Gran Sasso National Laboratory (Italy). It is devoted mainly to the real time spectroscopy of low energy solar neutrinos via the elastic scattering on electrons in the target mass. The data taking campaign started in 2007 and led to key measurements of 7}Be and 8B solar neutrinos as well as antineutrinos from the earth (geo-neutrinos) and from nuclear power reactors. Borexino is also a powerful tool for the study of cosmic muons that penetrate the Gran Sasso rock coverage and thereby induced signals such as neutrons and radioactive isotopes which are today of critical importance for upcoming dark matter and neutrino physics experiments. Having reached 4y of continuous data taking we analyze here the muon signal and its possible modulation. The muon flux is measured to be (3.41+-0.01)E-4/m2/s. A modulation of this signal with a yearly period is observed with an amplitude of (1.29+-0.07)% and a phase of (179+-6) d, corresponding to June 28th. Muon rate fluctuations are compared to fluctuations in the atmospheric temperature on a daily base, exploiting the most complete atmospheric data and models available. The distributions are shown to be positively correlated and the effective temperature coefficient is measured to be alpha_T = 0.93 +- 0.04. This result is in good agreement with the expectations of the kaon-inclusive model at the laboratory site and represents an improvement over previous measurements performed at the same depth.Comment: Proceedings of ICRC 2011 conference. 4 pages, 4 figure (+logo) Full list of authors in the published versio

    Regulation of ISWI chromatin remodelling activity

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    The packaging of the eukaryotic genome into chromatin facilitates the storage of the genetic information within the nucleus, but prevents the access to the underlying DNA sequences. Structural changes in chromatin are mediated by several mechanisms. Among them, ATP-dependent remodelling complexes belonging to ISWI family provides one of the best examples that eukaryotic cells evolved to finely regulate these changes. ISWI-containing complexes use the energy derived from ATP hydrolysis to rearrange nucleosomes on chromatin in order to favour specific nuclear reactions. The combination of regulatory nuclear factors associated with the ATPase subunit as well as its modulation by specific histone modifications, specializes the nuclear function of each ISWI-containing complex. Here we review the different ways by which ISWI enzymatic activity can be modulated and regulated in the nucleus of eukaryotic cells

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    Structural analysis of the double-walled copper-steel cryogenic chamber of the ASTAROTH experiment

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    This document describes the verification process of structural performance of the double- walled copper-steel cryogenic chamber of the ASTAROTH (All Sensitive crysTal ARray with lOw THreshold) experiment and the evaluation of the stresses generated near the thermal bridge connecting the inner and outer wall. The chamber consists of an external AISI 316L stainless steel dewar and an inner double-walled OF (Oxygen Free) copper dewar connected to an AISI 316L stainless steel flanged collar. The results showed that close to the thermal bridge (copper-steel junction) the stresses slightly exceed the YS of copper at the estimated operating temperature (localised strain-hardening condition). On the other hand, the safety coefficient respect to fracture is well above one for both materials. This condition, together with the fact that limited cooling cycles are expected during the operating life of the system, leads to the assumption that a progressive material hardening will occur in this area, thus locally raising the YS limit

    The effects of canrenone on inflammatory markers in patients with metabolic syndrome.

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    To evaluate the effects of canrenone compared to placebo on blood pressure control, some non-conventional biomarkers in cardiovascular stratification, and on metalloproteinases in patients affected by metabolic syndrome.A total of 156 Caucasian patients were treated with placebo or canrenone, 50 mg once a day, for 3 months and then 50 mg twice a day, till the end of the study. We evaluated: systolic (SBP) and diastolic blood pressure (DBP), body weight, body mass index (BMI), fasting plasma glucose (FPG), lipid profile, plasma aldosterone, creatinine, potassium, brain natriuretic peptide (BNP), metalloproteinases 2 and 9 (MMP-2 and -9), lipoprotein (a) (Lp(a)), and serum myeloperoxidase (MPO).We observed a significant decrease of SBP and DBP in the canrenone group compared to baseline. Canrenone gave a significant decrease of MMP-2 and -9, Lp(a), and MPO compared to baseline, not observed with placebo. Plasma aldosterone, but not BNP, decreased with canrenone, both compared to baseline and to placebo.Canrenone seems to be effective in reducing blood pressure in patients with metabolic syndrome. Moreover, canrenone seems also to improve MPO, Lp(a), and metalloproteinases in these patients

    ASSOCIATION OF CALCIFEDIOL LEVELS WITH VERTEBRAL FRACTURES, VASCULAR CALCIFICATIONS AND MORTALITY.

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    The best biomarker of Vitamin D status is calcifediol [25(OH)D]. We investigated the relationship between serum calcifediol levels and vertebral fractures (VF), vascular calcifications (VC) and mortality in hemodialysis patients. Within a multicenter, cross-sectional study in 18 hospital based dialysis centers in Italy, we included 387 hemodialysis patients (143 F, 37% ; 244 M, 63%), mean age 64±14 (SD) years, median dialytic age 49 months, BMI 25± 4 Kg/m2. We determined total 25(OH)D using the LIASON® 25 OH Vitamin D kit (DiaSorin Inc., Stillwater MN, USA). We evaluated VF with a computerized analysis of scanned L-L vertebral X-rays (T4 to L5). Reduction of > 20% of vertebral body height was considered a VF, while reductions between 15% and 20% were considered borderline fractures (BF). Fracture severity was estimated as mild, moderate or severe (reduction: 20–25%, 25–40% or >40%, respectively). VC assessments were also centralized. Witteman's method (Lancet, 1994) was used for blinded assessments in duplicate. VC were quantified by measuring the length of calcific deposits along the anterior and posterior wall of the aorta (mild 0.1-5 cm, moderate 5.1-10 cm and severe >10 cm). We also evaluated the presence or absence of calcifications of the iliac arteries in the same radiograph (mild 0.1-3 cm, moderate 3.1-5 cm and severe >5cm). Any differences in VC were resolved by consensus. Follow up was 2.7±0.5 years. Bone markers were: Ca 9.15±0.68 mg/dl, P 4.8± 1.28 mg/dl, median ALP 83 U/L and median PTH 244 pg/ml. We found a median 25(OH)D level of 28.9 ng/ml. Nine ( 2.3%) patients had vitamin D deficiency (30 ng/ml). We found that 55% of patients had VF and 30.9% of patients had BF. Prevalence of VC was 80.6% (mild 20.1%, moderate 30.8%, severe 29.7%) in the aorta and 55,1% in the iliac arteries. Males had more VF than Females (60% versus 48%, P=0.019). No associations were found between VF and biochemical parameters including calcifediol levels (p=0.662), while we found an association between low calcifediol levels and a higher prevalence of severe aortic calcifications (36.8 vs 28.2, p=0.0044). Furthermore, we found a OR 1.85 (1.04-3.29 CI, p=0.0367) for Aortic Calcification in patients with calcifediol levels lower than the median value of 29 ng/ml. During follow-up (2.7±0.5 years) mortality was of 19.9%. No association was found between mortality and calcifediol levels (p=0.5394). In conclusion, despite good control of bone and mineral metabolism parameters, hemodialysis patients showed high prevalence of VF and VC. Our study suggests that high calcifediol levels could be protective against progression of severe aortic calcificatio

    PABS: An online platform to assist BAC-by-BAC sequencing projects

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    Genome sequencing projects are either based on whole genome shotgun (WGS) or on a BAC-by-BAC strategy. Although WGS is in most cases the preferred choice, sometimes the BAC-by-BAC approach may be better because it requires a much simpler assembly process. Furthermore, when the study is limited to specific regions of the genome, the WGS would require an unjustified effort, making the BAC-by-BAC the only feasible strategy. In this paper we describe an informatics pipeline called PABS (Platform Assisted BAC-by-BAC Sequencing) that we developed to provide a tool to optimize the BAC-by-BAC sequencing strategy. PABS has two main functions: (i) PABS-Select, to choose suitable overlapping clones; and (ii) PABS-Validate, to verify whether a BAC under analysis is actually overlapping the neighboring BAC
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