Transverse Sizes of CIV Absorption Systems Measured from Multiple QSO Sightlines

We present tomography of the circum-galactic metal distribution at redshift 1.7 to 4.5 derived from echellete spectroscopy of binary quasars. We find CIV systems at similar redshifts in paired sightlines more often than expected for sightline-independent redshifts. As the separation of the sightlines increases from 36 kpc to 907 kpc, the amplitude of this clustering decreases. At the largest separations, the CIV systems cluster similar to Lyman-break galaxies (Adelberger et al. 2005a). The CIV systems are significantly less correlated than these galaxies, however, at separations less than R_1 ~ 0.42 +/- 0.15 h-1 comoving Mpc. Measured in real space, i.e., transverse to the sightlines, this length scale is significantly smaller than the break scale estimated from the line-of-sight correlation function in redshift space (Scannapieco et al. 2006a). Using a simple model, we interpret the new real-space measurement as an indication of the typical physical size of enriched regions. We adopt this size for enriched regions and fit the redshift-space distortion in the line-of-sight correlation function. The fitted velocity kick is consistent with the peculiar velocity of galaxies as determined by the underlying mass distribution and places an upper limit on the outflow (or inflow) speed of metals. The implied time scale for dispersing metals is larger than the typical stellar ages of Lyman-break galaxies (Shapley et al. 2001), and we argue that enrichment by galaxies at z > 4.3 played a greater role in dispersing metals. To further constrain the growth of enriched regions, we discuss empirical constraints on the evolution of the CIV correlation function with cosmic time. This study demonstrates the potential of tomography for measuring the metal enrichment history of the circum-galactic medium.Comment: 22 pages, 15 figures, 1 tabl

KECK HIRES Spectroscopy of APM 08279+5255

With an optical R-band magnitude of 15.2, the recently discovered z=3.911 BAL quasar APM 08279+5255 is an exceptionally bright high redshift source. Its brightness has allowed us to acquire a high signal-to-noise ratio (~100), high resolution (~6 km/s) spectrum using the HIRES echelle spectrograph on the 10-m Keck I telescope. Given the quality of the data, these observations provide an unprecedented view of associated and intervening absorption systems. Here we announce the availability of this spectrum to the general astronomical community and present a brief analysis of some of its main features.Comment: 21 pages including 5 figures. Accepted for publication by PAS

The HCP5 Single-Nucleotide Polymorphism: A Simple Screening Tool for Prediction of Hypersensitivity Reaction to Abacavir

The HLA-B*5701 allele is predictive of hypersensitivity reaction to abacavir, a response herein termed "ABC-HSR.” This study of 1103 individuals infected with human immunodeficiency virus assessed the usefulness of genotyping a HCP5 single-nucleotide polymorphism (SNP), rs2395029, in relation to ABC-HSR. In populations with European ancestry, rs2395029 is in linkage disequilibrium with HLA-B*5701. The HCP5SNP was present in all 98 HLA-B*5701—positive individuals and was absent in 999 of 1005 HLA-B*5701—negative individuals. rs2395029 was overrepresented in 25 individuals with clinically likely ABC-HSR, compared with its frequency in 175 ABC-tolerant individuals (80% vs. 2%, respectively; P < .0001). Therefore, HCP5 genotyping could serve as a simple screening tool for ABC-HSR, particularly in settings where sequence-based HLA typing is not availabl

IL-22 affects smooth muscle cell phenotype and plaque formation in apolipoprotein E knockout mice.

IL-22 is a recently discovered cytokine that belongs to the family of IL-10 related cytokines. It is produced by activated T-cells and innate lymphoid cells and has been suggested to be involved in tissue repair. As both inflammation and repair play important roles in atherosclerosis we investigated if IL-22 deficiency influences the disease process in Apoe(-/-) mice

Systematic review of clinical practice guidelines for adults with fractures: identification of best evidence for rehabilitation to develop the WHO’s Package of Interventions for Rehabilitation

Background The identification of existing rehabilitation interventions and related evidence represents a crucial step along the development of the World Health Organization’s (WHO) Package of Interventions for Rehabilitation (PIR). The methods for such identification have been developed by the WHO Rehabilitation Programme and Cochrane Rehabilitation under the guidance of the WHO’s Guideline Review Committee secretariat. The aim of this paper is to report on the results of the systematic search for clinical practice guidelines (CPGs) relevant to the rehabilitation of adults with fractures and to present the current state of evidence available from the identified CPGs. Methods This paper is part of the Best Evidence for Rehabilitation (be4rehab) series, developed according to the methodology presented in the World Health Organization’s (WHO) Package of Interventions for Rehabilitation (PIR) introductory paper. It is a systematic review of existing CPGs on fractures in adult population published from 2009 to 2019. Results We identified 23 relevant CPGs after title and abstract screening. According to inclusion/exclusion criteria, we selected 13 CPGs. After checking for quality, publication time, multiprofessionality, and comprehensiveness, we finally included five CPGs dealing with rehabilitative management of fractures in adult population, two CPGs addressing treatment of distal radius fracture and three the treatment of femoral/hip fracture. Conclusion The selected CPGs on management of distal radius and femoral/hip fracture include few recommendations regarding rehabilitation, with overall low to very low quality of evidence and weak/conditional strength of recommendation. Moreover, several gaps in specific rehabilitative topics occur. Further high-quality trials are required to upgrade the quality of the available evidence

A Bayesian network approach to study host and viral genetic correlates of HIV-1 disease progression

HIV disease progression is very variable among infected patients. Using classical statistical methods based on a selected number of markers, Casado et al [1] identified a number of host and viral genetic correlates for the clinical definitions of HIV-1 disease progression: elite controllers, long term non progressors including viremic controllers and clinical non progressors, regular progressors and rapid progressors.S

Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly

Background: The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L-) domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX), is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6. Results: Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF) reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA) and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site. Conclusions: Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively affects CA maturation and virus core formation, and consequently the infectivity of released virions

De Broglie Wavelength of a Nonlocal Four-Photon

Superposition is one of the most distinct features of quantum theory and has been demonstrated in numerous realizations of Young's classical double-slit interference experiment and its analogues. However, quantum entanglement - a significant coherent superposition in multiparticle systems - yields phenomena that are much richer and more interesting than anything that can be seen in a one-particle system. Among them, one important type of multi-particle experiments uses path-entangled number-states, which exhibit pure higher-order interference and allow novel applications in metrology and imaging such as quantum interferometry and spectroscopy with phase sensitivity at the Heisenberg limit or quantum lithography beyond the classical diffraction limit. Up to now, in optical implementations of such schemes lower-order interference effects would always decrease the overall performance at higher particle numbers. They have thus been limited to two photons. We overcome this limitation and demonstrate a linear-optics-based four-photon interferometer. Observation of a four-particle mode-entangled state is confirmed by interference fringes with a periodicity of one quarter of the single-photon wavelength. This scheme can readily be extended to arbitrary photon numbers and thus represents an important step towards realizable applications with entanglement-enhanced performance.Comment: 19 pages, 4 figures, submitted on November 18, 200

Discovery Of Cold, Pristine Gas Possibly Accreting Onto An Overdensity Of Star-Forming Galaxies At Redshift z ~ 1.6

We report the discovery of large amounts of cold (T ~ 10^4 K), chemically young gas in an overdensity of galaxies at redshift z ~ 1.6 in the Great Observatories Origins Deep Survey southern field (GOODS-S). The gas is identified thanks to the ultra-strong Mg II absorption features it imprints in the rest-frame UV spectra of galaxies in the background of the overdensity. There is no evidence that the optically-thick gas is part of any massive galaxy (i.e. M_star > 4x10^9 M_sun), but rather is associated with the overdensity; less massive and fainter galaxies (25.5 < z_850 < 27.5 mag) have too large an impact parameter to be causing ultra-strong absorption systems, based on our knowledge of such systems. The lack of corresponding Fe II absorption features, not detected even in co-added spectra, suggests that the gas is chemically more pristine than the ISM and outflows of star-forming galaxies at similar redshift, including those in the overdensity itself, and comparable to the most metal-poor stars in the Milky Way halo. A crude estimate of the projected covering factor of the high-column density gas (N_H >~ 10^20 cm-2) based on the observed fraction of galaxies with ultra-strong absorbers is C_F ~ 0.04. A broad, continuum absorption profile extending to the red of the interstellar Mg II absorption line by <~ 2000 km/s is possibly detected in two independent co-added spectra of galaxies of the overdensity, consistent with a large-scale infall motion of the gas onto the overdensity and its galaxies. Overall, these findings provides the first tentative evidence of accretion of cold, chemically young gas onto galaxies at high redshift, possibly feeding their star formation activity. The fact that the galaxies are members of a large structure, as opposed to field galaxies, might play a significant role in our ability to detect the accreting gas.Comment: 57 pages, 17 figures, 1 table; accepted for publication by ApJ (Aug 9, 2011); minor modifications to match the accepted versio

Coincident, 100 kpc-scale damped Lyman alpha absorption towards a binary QSO: how large are galaxies at z ~ 3?

We report coincident damped Lyman alpha (DLA) and sub-DLA absorption at z = 2.66 and z = 2.94 towards the z ~ 3 13.8 arcsecond separation binary quasar SDSS 1116+4118 AB. At the redshifts of the absorbers, this angular separation corresponds to a proper transverse separation of ~ 110 kpc. A third absorber, a sub-DLA at z = 2.47, is detected towards SDSS 1116+4118 B, but no corresponding high column density absorber is present towards SDSS 1116+4118 A. We use high resolution galaxy simulations and a clustering analysis to interpret the coincident absorption and its implications for galaxy structure at z ~ 3. We conclude that the common absorption in the two lines of sight is unlikely to arise from a single galaxy, or a galaxy plus satellite system, and is more feasibly explained by a group of two or more galaxies with separations ~ 100 kpc. The impact of these findings on single line of sight observations is also discussed; we show that abundances of DLAs may be affected by up to a few tenths of a dex by line of sight DLA blending. From a Keck ESI spectrum of the two quasars, we measure metal column densities for all five absorbers and determine abundances for the three absorbers with log N(HI) > 20. For the two highest N(HI) absorbers, we determine high levels of metal enrichment, corresponding to 1/3 and 1/5 solar. These metallicities are amongst the highest measured for DLAs at any redshift and are consistent with values measured in Lyman break galaxies at 2 < z < 3. For the DLA at z = 2.94 we also infer an approximately solar ratio of alpha-to-Fe peak elements from [S/Zn] = +0.05, and measure an upper limit for the molecular fraction in this particular line of sight of log f(H_2)< -5.5.Comment: Accepted for publication in MNRAS. Full resolution simulation images available in pdf copy of the manuscript at http://www.astro.uvic.ca/~sara/1116.pd