Measurement of CP violation in B0-B0bar mixing using semileptonic decays at LHCb

This thesis presents the measurement of the CP-violating asymmetry in B0-B0bar mixing using data corresponding to an integrated luminosity of 3.0 fb^{−1} collected at the LHCb experiment in proton-proton collisions at the center-of-mass energies of 7 TeV and 8 TeV. This analysis uses untagged, semileptonic B0 → D−μ+ν and B0 → D∗−μ+ν decays, where the D− decays into K+π−π−, and the D∗− decays into D0(→ K+π−)π−. The neutrino in the semileptonic B decays is not reconstructed. A decay time dependent fit allows to disentangle the CP asymmetry from the possible B0-B0bar production asymmetry. Detection and reconstruction asymmetries are calibrated using promptly produced Cabibbo-favored D+ decays, and inclusive secondary J/ψ decays. The CP-violating asymmetry is measured to be a^{d}_{sl} = (−0.02 ± 0.19 (stat) ± 0.30 (syst))% . This result is consistent with the Standard Model prediction, and it is the most precise measurement from a single experiment to date. This measurement is published in Physical Review Letter

Numerical simulations challenged on the prediction of massive subhalo abundance in galaxy clusters: the case of Abell 2142

In this Letter we compare the abundance of member galaxies of a rich, nearby ($z=0.09$) galaxy cluster, Abell 2142, with that of halos of comparable virial mass extracted from sets of state-of-the-art numerical simulations, both collisionless at different resolutions and with the inclusion of baryonic physics in the form of cooling, star formation, and feedback by active galactic nuclei. We also use two semi-analytical models to account for the presence of orphan galaxies. The photometric and spectroscopic information, taken from the Sloan Digital Sky Survey Data Release 12 (SDSS DR12) database, allows us to estimate the stellar velocity dispersion of member galaxies of Abell 2142. This quantity is used as proxy for the total mass of secure cluster members and is properly compared with that of subhalos in simulations. We find that simulated halos have a statistically significant ($\gtrsim 7$ sigma confidence level) smaller amount of massive (circular velocity above $200\,{\rm km\, s^{-1}}$) subhalos, even before accounting for the possible incompleteness of observations. These results corroborate the findings from a recent strong lensing study of the Hubble Frontier Fields galaxy cluster MACS J0416 \citep{grillo2015} and suggest that the observed difference is already present at the level of dark matter (DM) subhalos and is not solved by introducing baryonic physics. A deeper understanding of this discrepancy between observations and simulations will provide valuable insights into the impact of the physical properties of DM particles and the effect of baryons on the formation and evolution of cosmological structures.Comment: 8 pages, 2 figures. Modified to match the version published in ApJ

Occlus-o-Guide� versus Andresen activator appliance: neuromuscular evaluation

BACKGROUND: The aim of the present study was to assess the muscular variations at the electromyography (EMG) level for the anterior temporalis muscles and masseter muscles during treatment with Occlus-o-Guide(®) and Andresen activator appliances. METHODS: Eighty-two patients (35 males and 47 females) aged between 8 and 12 years (mean age, 10.5 ± 0.8 years) participated in the study. Fifty patients underwent treatment with an Occlus-o-Guide(®) and 32 patients with an Andresen activator. All patients underwent EMG examination using a Freely EMG (De Gotzen, Legnano, Italy) and surface bipolar electrodes when the appliances were worn for the first time (T0), and after 6 months (T1) and after 12 months (T2) of appliance use. RESULTS: Statistical analysis showed that both at T0 and T2, the percent overlapping coefficient (POC) of the anterior temporalis muscles was not statistically different between the appliance groups. At T0, the POC of the masseter muscles was significantly lower for the Andresen appliance as compared to the Occlus-o-Guide(®) (p = 0.02), while at T2 this significance was lost. CONCLUSIONS: At insertion of an appliance, all patients show neuromuscular balance that does not correspond to orthognathic occlusion. Both appliances work by creating muscular imbalance. With the appliances in situ, EMG responses were generally analogous for the Occlus-o-Guide(®) and the Andresen activator; however, the imbalance was greater and the recovery of the orthological muscular balance was slower in patients under treatment with the Andresen activator as compared to those with the Occlus-o-Guide(®)

Single Nucleotide Polymorphisms Of The Gjb2 And Gjb6 Genes Are Associated With Autosomal Recessive Nonsyndromic Hearing Loss

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Single nucleotide polymorphisms (SNPs) are important markers in many studies that link DNA sequence variations to phenotypic changes; such studies are expected to advance the understanding of human physiology and elucidate the molecular basis of diseases. The DFNB1 locus, which contains the GJB2 and GJB6 genes, plays a key role in nonsyndromic hearing loss. Previous studies have identified important mutations in this locus, but the contribution of SNPs in the genes has not yet been much investigated. The aim of this study was to investigate the association of nine polymorphisms located within the DFNB1 locus with the occurrence of autosomal recessive nonsyndromic hearing loss (ARNSHL). The SNPs rs3751385 (C/T), rs7994748 (C/T), rs7329857 (C/T), rs7987302 (G/A), rs7322538 (G/A), rs9315400 (C/T), rs877098 (C/T), rs945369 (A/C), and rs7333214 (T/G) were genotyped in 122 deaf patients and 132 healthy controls using allele-specific PCR. There were statistically significant differences between patients and controls, in terms of allelic frequencies in the SNPs rs3751385, rs7994748, rs7329857, rs7987302, rs945369, and rs7333214 (P < 0.05). No significant differences between the two groups were observed for rs7322538, rs9315400, and rs877098. Our results suggest that SNPs present in the GJB2 and GJB6 genes may have an influence on ARNSHL in humans.Fundacao Herminio Ometto/FHOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Golden gravitational lensing systems from the Sloan Lens ACS Survey. II. SDSS J1430+4105: A precise inner total mass profile from lensing alone

We study the SLACS strong lensing system SDSSJ1430+4105 at z=0.285. The lensed source (z=0.575) of this system has a complex morphology with several subcomponents. Its subcomponents span a radial range from 4 to 10kpc in the lens plane. Therefore we can constrain the slope of the total projected mass profile around the Einstein radius (R_E) from lensing alone. We measure a density profile that is slightly but not significantly shallower than isothermal at R_E. We decompose the mass of the lensing galaxy into a de Vaucouleurs (deV) component to trace the stars and an additional dark component. The spread of multiple image components over a large radial range also allows us to determine the amplitude of the deV and dark matter components separately. We get a mass to light ratio of M_deV/L_B~5.5\pm1.5M/L_sun,B and a dark matter fraction within R_E of ~20 to 40%. Modelling the star formation history assuming composite stellar populations at solar metallicity to the galaxy's photometry yields a mass to light ratio of M_star,salp/L_B~4.0_{-1.3}^{+0.6}M/L_sun,B and M_star,chab/L_B~2.3_{-0.8}^{+0.3}M/L_sun,B for Salpeter and Chabrier IMFs, respectively. Hence, the mass to light ratio derived from lensing is more Salpeter-like, in agreement with results for massive Coma galaxies and other nearby massive early type galaxies. We examine the consequences of the galaxy group in which the lensing galaxy is embedded, showing that it has little influence on the mass to light ratio obtained for the deV component of the lensing galaxy. Finally, we decompose the projected, azimuthally averaged 2D density distribution of the deV and dark matter component of the lensing signal into spherically averaged 3D density profiles. We can show that the 3D dark and luminous matter density within R_E~0.6R_eff of this SLACS galaxy is similar to the values of Coma galaxies with the same velocity dispersions.Comment: 24 pages, 21 figures, 11 tables, accepted for publication by MNRA

A twelve-image gravitational lens system in the z ~ 0.84 cluster Cl J0152.7-1357

Gravitational lens modeling is presented for the first discovered example of a three-component source for which each component is quadruply imaged. The lens is a massive galaxy member of the cluster Cl J0152.7-1357 at z ~ 0.84. Taking advantage of this exceptional configuration and of the excellent angular resolution of the HST/ACS, we measure the properties of the lens. Several parametric macroscopic models were developed for the lens galaxy, starting from pointlike to extended image models. For a lens model in terms of a singular isothermal sphere with external shear, the Einstein radius is found to be R_{E} = (9.54 +/- 0.15) kpc. The external shear points to the cluster's northern mass peak. The unknown redshift of the source is determined to be higher than 1.9 and lower than 2.9. Our estimate of the lensing projected total mass inside the Einstein radius, M_{len}(R < 9.54 kpc), depends on the source distance and lies between 4.6 and 6.2 x 10^{11} M_{Sun}. This result turns out to be compatible with the dynamical estimate based on an isothermal model. By considering the constraint on the stellar mass-to-light ratio that comes from the evolution of the Fundamental Plane, we can exclude the possibility that at more than 4 sigma level the total mass enclosed inside the Einstein ring is only luminous matter. Moreover, the photometric-stellar mass measurement within the Einstein radius gives a minimum value of 50% (1 sigma) for the dark-to-total matter fraction. The lensing analysis has allowed us to investigate the distribution of mass of the deflector, also providing some interesting indications on scales that are larger and smaller than the Einstein radius of the lens galaxy. The combination of different diagnostics has proved to be essential in determining quantities that otherwise would have not been directly measurable with the current data.Comment: 10 pages, 9 figures, accepted by Astronomy & Astrophysic

Safety and Efficacy of Surgery for Metastatic Tumor to the Pancreas: A Single-Center Experience

Pancreatic metastases from other neoplasms are rare. The role of surgery for this clinical entity is unclear. The aim of this study was to investigate the role of resection in patients with pancreatic secondary lesions. We observed 44 patients with pancreatic metastases from other tumors. Renal cell carcinoma was the most common primary tumor (n = 19, 43.2%). Thirty-seven patients underwent surgery, and pancreatic resection with curative intent was feasible in 35 cases. Fifteen patients (43.2%) experienced major postoperative complications (Clavien-Dindo > 2), and postoperative mortality rate was 5.4%. The median overall survival and disease-free survival were 38 (range 0–186) and 11 (range 0–186) months, respectively. Overall survival and disease-free survival were significantly longer for pancreatic metastases from renal cell carcinoma when compared to other primary tumors. Multivariate analysis confirmed a pathological diagnosis of metastasis from RCC as an independent prognostic factor for overall survival (OR 2.48; 95% CI, 1.00–6.14; p = 0.05). In conclusion, radical resection of metastases to the pancreas is feasible and safe, and may confer a survival benefit for selected patients. There is a clear benefit of metastasectomy in terms of patient survival for metastases from renal cell carcinoma, while for those with other primary tumors, surgery seems to be mainly palliative

Defect-free zinc blende InSb nanowires

Among the III-V semiconductors, InSb has the smallest bandgap, highest bulk electron mobility, smallest effective mass, and largest Land? g-factor [1]. These properties make this material suited for many applications in high-speed devices, magnetoresistors, magnetic sensors, and infrared detectors. Yet very few reports on InSb NWs have so far appeared in literature. Notably, a recent paper on InAs/InSb heterostructures grown on InAs(111)B substrates by metal-organic vapor phase epitaxy [2] showed controlled growth direction, and perfect zincblende (ZB) crystal structure, free of defects. We shall report our results on the growth of InAs-InSb nanowire heterostructures (NWs). Chemical beam epitaxy technique was employed for Au-assisted growth on InAs(111)B substrates in a Riber Compact-21 system. The NWs are composed of two sections of different diameter; the lower one (InAs, as confirmed by EDXS) has a smaller diameter, while the upper one (InSb) has a larger diameter, comparable with the catalyst particle diameter. The structure and the crystalline quality of the NWs were investigated by TEM. A typical HRTEM image of the InAs/InSb interfacial region viewed along <112> InSb zone axis is shown in Fig. 1(a). The associated fast Fourier transform, shown in Fig. 1(b) indicates that the InAs base (blue spots) grows with wurtzite (WZ) structure with the c axis along the NW growth direction, whereas the InSb segment on top (red spots) crystallizes in the ZB phase with the <111> direction aligned to the NW axis. TEM analysis of the interfacial region (see Fig. 1(c)) highlights the abruptness of the interface and the good crystalline quality of the NWs in the near-interface region. Furthermore, we have performed post-growth studies investigating the NW tip composition following different cool-down protocol after InSb growth. We have found that the catalyst particle composition is AuIn2, and it can be varied to an AuIn alloy by cooling down the samples under TDMASb flux. [1] S. J. Chung, K. J. Goldammer, S. C. Lindstrom, M. B. Johnson, and M. B. Santos, J. Vac. Sci. Technol. B 17, 1151 (1999). [2] P. Caroff, J. Wagner, K. Dick, H. Nilsson, M. Jeppsson, K. Deppert, L. Samuelson, L.Wallenberg, and L.Wernersson, Smal l 4, 878 (2008).vedi abstract ingles

Haemodynamic Adaptive Mechanisms at High Altitude: Comparison between European Lowlanders and Nepalese Highlanders

Background: Exposure to high altitudes determines several adaptive mechanisms affecting in a complex way the whole cardiovascular, respiratory, endocrine systems because of the hypobaric hypoxic condition. The aim of our study was to evaluate the circulatory adaptive mechanisms at high altitudes, during a scientific expedition in the Himalayas. Methods: Arterial distensibility was assessed measuring carotid-radial and carotid-femoral pulse wave velocity. Tests were carried out at several altitudes, from 1350 to 5050 m above sea level, on 8 lowlander European researchers and 11 highlander Nepalese porters. Results: In Europeans, systolic blood pressure and pulse pressure increased slightly but significantly with altitude (p < 0.05 and p < 0.001, respectively). Norepinephrine showed a significant increase after the lowlanders had spent some time at high altitude (p < 0.001). With increasing altitude, a progressive increase in carotid-radial and carotid-femoral pulse wave velocity values was observed in lowlanders, showing a particularly significant increase (p < 0.001) after staying at high altitude (carotid-radial pulse wave velocity, median value (interquartile range) from 9.2 (7.9-10.0) to 11.2 (10.9-11.8) m/s and carotid-femoral pulse wave velocity from 8.5 (7.9-9.0) to 11.3 (10.9-11.8) m/s). At high altitudes (3400 and 5050 m above sea level), no significant differences were observed between highlanders and lowlanders in hemodynamic parameters (blood pressure, carotid-radial and carotid-femoral pulse wave velocity). Conclusions: The progressive arterial stiffening with altitude observed in European lowlanders could explain the increase in systolic and pulse pressure values observed at high altitudes in this ethnic group. Further studies are needed to evaluate the role of aortic stiffening in the pathogenesis of acute mountain sickness