Neutrino mass bounds from confronting an effective model with BOSS Lyman-alpha data

We present an effective model for the one-dimensional Lyman-$\alpha$ flux power spectrum far above the baryonic Jeans scale. The main new ingredient is constituted by a set of two parameters that encode the impact of small, highly non-linear scales on the one-dimensional power spectrum on large scales, where it is measured by BOSS. We show that, by marginalizing over the model parameters that capture the impact of the intergalactic medium, the flux power spectrum from both simulations and observations can be described with high precision. The model displays a degeneracy between the neutrino masses and the (unknown, in our formalism) normalization of the flux power spectrum. This degeneracy can be lifted by calibrating one of the model parameters with simulation data, and using input from Planck CMB data. We demonstrate that this approach can be used to extract bounds on the sum of neutrino masses with comparably low numerical effort, while allowing for a conservative treatment of uncertainties from the dynamics of the intergalactic medium. An explorative analysis yields an upper bound of $0.16\,$eV at $95\%$ C.L. when applied to BOSS data at $3\leq z\leq 4.2$. We also forecast that if the systematic and statistical errors will be reduced by a factor two the upper bound will become $0.1\,$eV at $95\%$ C.L.Comment: 27 pages, 11 figure

A comparison of discrete versus continuous environment in a variance components-based linkage analysis of the COGA data

BACKGROUND: The information content of a continuous variable exceeds that of its categorical counterpart. The parameterization of a model may diminish the benefit of using a continuous variable. We explored the use of continuous versus discrete environment in variance components based analyses examining gene × environment interaction in the electrophysiological phenotypes from the Collaborative Study on the Genetics of Alcoholism. RESULTS: The parameterization using the continuous environment produced a greater number of significant gene × environment interactions and lower AICs (Akaike's information criterion). In these cases, the genetic variance increased with increasing cigarette pack-years, the continuous environment of interest. This did not, however, result in enhanced LOD scores when linkage analyses incorporated the gene × continuous environment interaction. CONCLUSION: Alternative parameterizations may better represent the functional relationship between the continuous environment and the genetic variance

Possible evidence for a large-scale enhancement in the Lyman-α\alpha forest power spectrum at redshift z≥4\mathbf{\textit{z}\geq 4}

Inhomogeneous reionization enhances the 1D Lyman-$\alpha$ forest power spectrum on large scales at redshifts $z\geq4$. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the post-reionization gas temperature, which fade as the gas cools. It is therefore possible to use these relic fluctuations to constrain inhomogeneous reionization with the power spectrum at wavenumbers $\log_{10}(k/{\rm km^{-1}\,s})\lesssim -1.5$. We use the Sherwood-Relics suite of hybrid radiation hydrodynamical simulations to perform a first analysis of new Lyman-$\alpha$ forest power spectrum measurements at $4.0\leq z \leq 4.6$. These data extend to wavenumbers $\log_{10}(k/{\rm km^{-1}\,s})\simeq -3$, with a relative uncertainty of $10$--$20$ per cent in each wavenumber bin. Our analysis returns a $2.7\sigma$ preference for an enhancement in the Lyman-$\alpha$ forest power spectrum at large scales, in excess of that expected for a spatially uniform ultraviolet background. This large-scale enhancement could be a signature of inhomogeneous reionization, although the statistical precision of these data is not yet sufficient for obtaining a robust detection of the relic post-reionization fluctuations. We show that future power spectrum measurements with relative uncertainties of $\lesssim 2.5$ per cent should provide unambiguous evidence for an enhancement in the power spectrum on large scales.Comment: Accepted by MNRAS, 13 pages, 8 figure

Contribution of MUTYH variants to male breast cancer risk: results from a multicenter study in Italy

Inherited mutations in BRCA1, and, mainly, BRCA2 genes are associated with increased risk of male breast cancer (MBC). Mutations in PALB2 and CHEK2 genes may also increase MBC risk. Overall, these genes are functionally linked to DNA repair pathways, highlighting the central role of genome maintenance in MBC genetic predisposition. MUTYH is a DNA repair gene whose biallelic germline variants cause MUTYH-associated polyposis (MAP) syndrome. Monoallelic MUTYH variants have been reported in families with both colorectal and breast cancer and there is some evidence on increased breast cancer risk in women with monoallelic variants. In this study, we aimed to investigate whether MUTYH germline variants may contribute to MBC susceptibility. To this aim, we screened the entire coding region of MUTYH in 503 BRCA1/2 mutation negative MBC cases by multigene panel analysis. Moreover, we genotyped selected variants, including p.Tyr179Cys, p.Gly396Asp, p.Arg245His, p.Gly264Trpfs*7, and p.Gln338His, in a total of 560 MBC cases and 1,540 male controls. Biallelic MUTYH pathogenic variants (p.Tyr179Cys/p.Arg241Trp) were identified in one MBC patient with phenotypic manifestation of adenomatous polyposis. Monoallelic pathogenic variants were identified in 14 (2.5%) MBC patients, in particular, p.Tyr179Cys was detected in seven cases, p.Gly396Asp in five cases, p.Arg245His and p.Gly264Trpfs*7 in one case each. The majority of MBC cases with MUTYH pathogenic variants had family history of cancer including breast, colorectal, and gastric cancers. In the case-control study, an association between the variant p.Tyr179Cys and increased MBC risk emerged by multivariate analysis [odds ratio (OR) = 4.54; 95% confidence interval (CI): 1.17-17.58; p = 0.028]. Overall, our study suggests that MUTYH pathogenic variants may have a role in MBC and, in particular, the p.Tyr179Cys variant may be a low/moderate penetrance risk allele for MBC. Moreover, our results suggest that MBC may be part of the tumor spectrum associated with MAP syndrome, with implication in the clinical management of patients and their relatives. Large-scale collaborative studies are needed to validate these findings

Las estrategias de acompañamiento a las trayectorias académicas de los alumnos de los primeros años: Talleres de Orientación Vocacional y el Sistema Integral de Tutorías : Un estudio de casos de los alumnos de la carrera de Derecho de la Universidad Nacional de La Matanza

La presente investigación intentará dar cuenta del impacto generado en la trayectoria académica de los alumnos a partir de su participación en las estrategias de acompañamiento implementadas desde la Dirección de Pedagogía Universitaria tales como los Talleres de Orientación Vocacional y el Sistema Integral de Tutorías. Estos espacios están destinadas a los alumnos aspirantes a ingresar a la UNLaM y a los alumnos de los primeros años de las Carreras de la UNLaM, respectivamente. Dicha investigación se enmarca en el Programa de Investigación CyTMA2 de la Secretaría y Ciencia de la UNLaM, e incluye los períodos 2015-2016.Secretaría de Asuntos Académico

Unveiling Dark Matter free-streaming at the smallest scales with high redshift Lyman-alpha forest

This study introduces novel constraints on the free-streaming of thermal relic warm dark matter (WDM) from Lyman-$\alpha$ forest flux power spectra. Our analysis utilises a high-resolution, high-redshift sample of quasar spectra observed using the HIRES and UVES spectrographs ($z=4.2-5.0$). We employ a Bayesian inference framework and a simulation-based likelihood that encompasses various parameters including the free-streaming of dark matter, cosmological parameters, the thermal history of the intergalactic medium, and inhomogeneous reionization, to establish lower limits on the mass of a thermal relic WDM particle of $5.7\;\mathrm{keV}$ (at 95\% C.L.). This result surpasses previous limits from the Lyman-$\alpha$ forest through reduction of the measured uncertainties due to a larger statistical sample and by measuring clustering to smaller scales ($k_{\rm max}=0.2\;\mathrm{km^{-1}\,s}$). The approximately two-fold improvement due to the expanded statistical sample suggests that the effectiveness of Lyman-$\alpha$ forest constraints on WDM models at high redshifts are limited by the availability of high-quality quasar spectra. Restricting the analysis to comparable scales and thermal history priors as in prior studies ($k_{\rm max}<0.1\;\mathrm{km^{-1}\,s}$) lowers the bound on the WDM mass to $4.1\;\mathrm{keV}$. As the precision of the measurements increases, it becomes crucial to examine the instrumental and modelling systematics. On the modelling front, we argue that the impact of the thermal history uncertainty on the WDM particle mass constraint has diminished due to improved independent observations. At the smallest scales, the primary source of modeling systematic arises from the structure in the peculiar velocity of the intergalactic medium and inhomogeneous reionization.Comment: 22 pages, 14 figures, 2 tables; submitte

Cosmology with a SKA HI intensity mapping survey

Advancing Astrophysics with the Square Kilometre Array June 8-13, 2014 Giardini Naxos, ItalyHI intensity mapping (IM) is a novel technique capable of mapping the large-scale structure of the Universe in three dimensions and delivering exquisite constraints on cosmology, by using HI as a biased tracer of the dark matter density field. This is achieved by measuring the intensity of the redshifted 21cm line over the sky in a range of redshifts without the requirement to resolve individual galaxies. In this chapter, we investigate the potential of SKA1 to deliver HI intensity maps over a broad range of frequencies and a substantial fraction of the sky. By pinning down the baryon acoustic oscillation and redshift space distortion features in the matter power spectrum – thus determining the expansion and growth history of the Universe – these surveys can provide powerful tests of dark energy models and modifications to General Relativity. They can also be used to probe physics on extremely large scales, where precise measurements of spatial curvature and primordial non-Gaussianity can be used to test inflation; on small scales, by measuring the sum of neutrino masses; and at high redshifts where non-standard evolution models can be probed. We discuss the impact of foregrounds as well as various instrumental and survey design parameters on the achievable constraints. In particular we analyse the feasibility of using the SKA1 autocorrelations to probe the large-scale signal.Web of Scienc

Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4

Inhomogeneous reionization enhances the 1D Lyα forest power spectrum on large scales at redshifts z ≥ 4. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the post-reionization gas temperature, which fade as the gas cools. It is therefore possible to use these relic fluctuations to constrain inhomogeneous reionization with the power spectrum at wavenumbers log10(k/km−1 s) ≲ −1.5. We use the Sherwood-Relics suite of hybrid radiation hydrodynamical simulations to perform a first analysis of new Lyα forest power spectrum measurements at 4.0 ≤ z ≤ 4.6. These data extend to wavenumbers log10(k/km−1 s) ≃ −3, with a relative uncertainty of 10–20 per cent in each wavenumber bin. Our analysis returns a 2.7σ preference for an enhancement in the Lyα forest power spectrum at large scales, in excess of that expected for a spatially uniform ultraviolet background. This large-scale enhancement could be a signature of inhomogeneous reionization, although the statistical precision of these data is not yet sufficient for obtaining a robust detection of the relic post-reionization fluctuations. We show that future power spectrum measurements with relative uncertainties of ≲ 2.5 per cent should provide unambiguous evidence for an enhancement in the power spectrum on large scales

The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery

We use the Sherwood–Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionization on the 1D power spectrum of the Lyman α (Lyα) forest transmitted flux at redshifts 4.2 ≤ z ≤ 5. Relative to models that assume a homogeneous ultraviolet background, reionization suppresses the power spectrum at small scales, k ∼ 0.1 km−1 s, by ∼10 per cent because of spatial variations in the thermal broadening kernel and the divergent peculiar velocity field associated with overpressurized intergalactic gas. On larger scales, k 4, 0.006≤k≤0.2km−1s⁠, we find inhomogeneous reionization does not introduce any significant bias in thermal parameter recovery for the current measurement uncertainties of ∼10 per cent. However, for 5 per cent uncertainties, ∼1σ shifts between the estimated and true parameters occur