Measuring our universe from galaxy redshift surveys

Galaxy redshift surveys have achieved significant progress over the last couple of decades. Those surveys tell us in the most straightforward way what our local universe looks like. While the galaxy distribution traces the bright side of the universe, detailed quantitative analyses of the data have even revealed the dark side of the universe dominated by non-baryonic dark matter as well as more mysterious dark energy (or Einstein's cosmological constant). We describe several methodologies of using galaxy redshift surveys as cosmological probes, and then summarize the recent results from the existing surveys. Finally we present our views on the future of redshift surveys in the era of Precision Cosmology.Comment: 82 pages, 31 figures, invited review article published in Living Reviews in Relativity, http://www.livingreviews.org/lrr-2004-

Propylene glycol inactivates respiratory viruses and prevents airborne transmission

Viruses are vulnerable as they transmit between hosts, and we aimed to exploit this critical window. We found that the ubiquitous, safe, inexpensive and biodegradable small molecule propylene glycol (PG) has robust virucidal activity. Propylene glycol rapidly inactivates a broad range of viruses including influenza A, SARS-CoV-2 and rotavirus and reduces disease burden in mice when administered intranasally at concentrations commonly found in nasal sprays. Most critically, vaporised PG efficiently abolishes influenza A virus and SARS-CoV-2 infectivity within airborne droplets, potently preventing infection at levels well below those tolerated by mammals. We present PG vapour as a first-in-class non-toxic airborne virucide that can prevent transmission of existing and emergent viral pathogens, with clear and immediate implications for public health

Identification of Escherichia coli strains from water vending machines of Kelantan, Malaysia using 16S rRNA gene sequence analysis

Water vending machines provide an alternative source of clean and safe drinking water to the consumers. However, the quality of drinking water may alter due to contamination from lack of hygienic practices and maintenance of the machines. Hence, this study was conducted to determine the microbiological quality of water from vending machines and associated contact surfaces. Seventeen water samples and 85 swab samples (nozzles, drip trays, coin slots, buttons and doors) from 3 locations in Kelantan were collected. Polymerase chain reaction amplification and 16S ribosomal ribonucleic acid (rRNA) sequencing were carried out and sequences obtained were compared against the sequences available in the National Centre for Biotechnology Information database using the basic local alignment search tool programme. Coliform counts were observed in 94.12 % of water samples, 76.47 % of nozzles and 82.35 % of drip tray swabs. Furthermore, results of 16S rRNA sequence analysis indicated that two gram-negative isolates were identified as Escherichia coli U 5/41 (Accession no. NR_024570.1) and E. coli O157:H7 EDL933 (Accession no. CP008957.1) with similarity value of 100 %, respectively. The results from this study further improve our understanding of the potential microorganisms in drinking water. Regular maintenance and cleaning of water vending machines are important to reduce bacterial growth and the presence of waterborne pathogens

Failure to rescue patients after emergency laparotomy for large bowel perforation: analysis of the National Emergency Laparotomy Audit (NELA).

BACKGROUND: Past studies have highlighted variation in in-hospital mortality rates among hospitals performing emergency laparotomy for large bowel perforation. The aim of this study was to investigate whether failure to rescue (FTR) contributes to this variability. METHODS: Patients aged 18 years or over requiring surgery for large bowel perforation between 2013 and 2016 were extracted from the National Emergency Laparotomy Audit (NELA) database. Information on complications were identified using linked Hospital Episode Statistics data and in-hospital deaths from the Office for National Statistics. The FTR rate was defined as the proportion of patients dying in hospital with a recorded complication, and was examined in hospitals grouped as having low, medium or high overall postoperative mortality. RESULTS: Overall, 6413 patients were included with 1029 (16.0 per cent) in-hospital deaths. Some 3533 patients (55.1 per cent) had at least one complication: 1023 surgical (16.0 per cent) and 3332 medical (52.0 per cent) complications. There were 22 in-hospital deaths following a surgical complication alone, 685 deaths following a medical complication alone, 150 deaths following both a surgical and medical complication, and 172 deaths with no recorded complication. The risk of in-hospital death was high among patients who suffered either type of complication (857 deaths in 3533 patients; FTR rate 24.3 per cent): 172 deaths followed a surgical complication (FTR-surgical rate 16.8 per cent) and 835 deaths followed a medical complication (FTR-medical rate of 25.1 per cent). After adjustment for patient characteristics and hospital factors, hospitals grouped as having low, medium or high overall postoperative mortality did not have different FTR rates (P = 0.770). CONCLUSION: Among patients having emergency laparotomy for large bowel perforation, efforts to reduce the risk of in-hospital death should focus on reducing avoidable complications. There was no evidence of variation in FTR rates across National Health Service hospitals in England

Genome-wide association study identifies loci associated with liability to alcohol and drug dependence that is associated with variability in reward-related ventral striatum activity in African- and European-Americans.

Genetic influences on alcohol and drug dependence partially overlap, however, specific loci underlying this overlap remain unclear. We conducted a genome-wide association study (GWAS) of a phenotype representing alcohol or illicit drug dependence (ANYDEP) among 7291 European-Americans (EA; 2927 cases) and 3132 African-Americans (AA: 1315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism. ANYDEP was heritable (h 2 in EA = 0.60, AA = 0.37). The AA GWAS identified three regions with genome-wide significant (GWS; P < 5E-08) single nucleotide polymorphisms (SNPs) on chromosomes 3 (rs34066662, rs58801820) and 13 (rs75168521, rs78886294), and an insertion-deletion on chromosome 5 (chr5:141988181). No polymorphisms reached GWS in the EA. One GWS region (chromosome 1: rs1890881) emerged from a trans-ancestral meta-analysis (EA + AA) of ANYDEP, and was attributable to alcohol dependence in both samples. Four genes (AA: CRKL, DZIP3, SBK3; EA: P2RX6) and four sets of genes were significantly enriched within biological pathways for hemostasis and signal transduction. GWS signals did not replicate in two independent samples but there was weak evidence for association between rs1890881 and alcohol intake in the UK Biobank. Among 118 AA and 481 EA individuals from the Duke Neurogenetics Study, rs75168521 and rs1890881 genotypes were associated with variability in reward-related ventral striatum activation. This study identified novel loci for substance dependence and provides preliminary evidence that these variants are also associated with individual differences in neural reward reactivity. Gene discovery efforts in non-European samples with distinct patterns of substance use may lead to the identification of novel ancestry-specific genetic markers of risk

Evaluating priority setting success in healthcare: a pilot study

<p>Abstract</p> <p>Background</p> <p>In healthcare today, decisions are made in the face of serious resource constraints. Healthcare managers are struggling to provide high quality care, manage resources effectively, and meet changing patient needs. Healthcare managers who are constantly making difficult resource decisions desire a way to improve their priority setting processes. Despite the wealth of existing priority setting literature (for example, program budgeting and marginal analysis, accountability for reasonableness, the 'describe-evaluate-improve' strategy) there are still no tools to evaluate how healthcare resources are prioritised. This paper describes the development and piloting of a process to evaluate priority setting in health institutions. The evaluation process was designed to examine the procedural and substantive dimensions of priority setting using a multi-methods approach, including a staff survey, decision-maker interviews, and document analysis.</p> <p>Methods</p> <p>The evaluation process was piloted in a mid-size community hospital in Ontario, Canada while its leaders worked through their annual budgeting process. Both qualitative and quantitative methods were used to analyze the data.</p> <p>Results</p> <p>The evaluation process was both applicable to the context and it captured the budgeting process. In general, the pilot test provided support for our evaluation process and our definition of success, (i.e., our conceptual framework).</p> <p>Conclusions</p> <p>The purpose of the evaluation process is to provide a simple, practical way for an organization to better understand what it means to achieve success in its priority setting activities and identify areas for improvement. In order for the process to be used by healthcare managers today, modification and contextualization of the process are anticipated. As the evaluation process is applied in more health care organizations or applied repeatedly in an organization, it may become more streamlined.</p

The 2dF galaxy redshift survey: near-infrared galaxy luminosity functions

We combine the Two Micron All Sky Survey (2MASS) Extended Source Catalogue and the 2dF Galaxy Redshift Survey to produce an infrared selected galaxy catalogue with 17 173 measured redshifts. We use this extensive data set to estimate the galaxy luminosity functions in the J- and KS-bands. The luminosity functions are fairly well fitted by Schechter functions with parameters MJ*−5 log h=−22.36±0.02, αJ=−0.93±0.04, ΦJ*=0.0104±0.0016 h3 Mpc3 in the J-band and MKS*−5 log h=−23.44±0.03, αKS=−0.96±0.05, ΦKS*=0.0108±0.0016 h3 Mpc3 in the KS-band (2MASS Kron magnitudes). These parameters are derived assuming a cosmological model with Ω0=0.3 and Λ0=0.7. With data sets of this size, systematic rather than random errors are the dominant source of uncertainty in the determination of the luminosity function. We carry out a careful investigation of possible systematic effects in our data. The surface brightness distribution of the sample shows no evidence that significant numbers of low surface brightness or compact galaxies are missed by the survey. We estimate the present-day distributions of bJ−KS and J−KS colours as a function of the absolute magnitude and use models of the galaxy stellar populations, constrained by the observed optical and infrared colours, to infer the galaxy stellar mass function. Integrated over all galaxy masses, this yields a total mass fraction in stars (in units of the critical mass density) of Ωstarsh =(1.6±0.24)×103 for a Kennicutt initial mass function (IMF) and Ωstarsh =(2.9±0.43)×103 for a Salpeter IMF. These values are consistent with those inferred from observational estimates of the total star formation history of the Universe provided that dust extinction corrections are modest

The 2dF Galaxy Redshift Survey: correlation functions, peculiar velocities and the matter density of the Universe

We present a detailed analysis of the two-point correlation function, ξ(σ, π), from the 2dF Galaxy Redshift Survey (2dFGRS). The large size of the catalogue, which contains ∼220 000 redshifts, allows us to make high-precision measurements of various properties of the galaxy clustering pattern. The effective redshift at which our estimates are made is zs≈ 0.15, and similarly the effective luminosity, Ls≈ 1.4L*. We estimate the redshift-space correlation function, ξ(s), from which we measure the redshift-space clustering length, s0= 6.82 ± 0.28 h−1 Mpc. We also estimate the projected correlation function, Ξ(σ), and the real-space correlation function, ξ(r), which can be fit by a power law (r/r0), with r0= 5.05 ± 0.26 h−1 Mpc, γr= 1.67 ± 0.03. For r≳ 20 h−1 Mpc, ξ drops below a power law as, for instance, is expected in the popular Λ cold dark matter model. The ratio of amplitudes of the real- and redshift-space correlation functions on scales of 8–30 h−1 Mpc gives an estimate of the redshift-space distortion parameter β. The quadrupole moment of ξ(σ, π) on scales 30–40 h−1 Mpc provides another estimate of β. We also estimate the distribution function of pairwise peculiar velocities, ƒ(v), including rigorously the significant effect due to the infall velocities, and we find that the distribution is well fit by an exponential form. The accuracy of our ξ(σ, π) measurement is sufficient to constrain a model, which simultaneously fits the shape and amplitude of ξ(r) and the two redshift-space distortion effects parametrized by β and velocity dispersion, a. We find β= 0.49 ± 0.09 and a= 506 ± 52 km s−1, although the best-fitting values are strongly correlated. We measure the variation of the peculiar velocity dispersion with projected separation, a(σ), and find that the shape is consistent with models and simulations. This is the first time that β and ƒ(v) have been estimated from a self-consistent model of galaxy velocities. Using the constraints on bias from recent estimates, and taking account of redshift evolution, we conclude that β (L=L*, z= 0) = 0.47 ± 0.08, and that the present-day matter density of the Universe, Ωm≈ 0.3, consistent with other 2dFGRS estimates and independent analyses

Strong interface-induced spin-orbit coupling in graphene on WS2

Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of graphene on hexagonal boron nitride (hBN) substrates. Ongoing research strives to explore interfacial interactions in a broader class of materials in order to engineer targeted electronic properties. Here we show that at an interface with a tungsten disulfide (WS2) substrate, the strength of the spin-orbit interaction (SOI) in graphene is very strongly enhanced. The induced SOI leads to a pronounced low-temperature weak anti-localization (WAL) effect, from which we determine the spin-relaxation time. We find that spin-relaxation time in graphene is two-to-three orders of magnitude smaller on WS2 than on SiO2 or hBN, and that it is comparable to the intervalley scattering time. To interpret our findings we have performed first-principle electronic structure calculations, which both confirm that carriers in graphene-on-WS2 experience a strong SOI and allow us to extract a spin-dependent low-energy effective Hamiltonian. Our analysis further shows that the use of WS2 substrates opens a possible new route to access topological states of matter in graphene-based systems.Comment: Originally submitted version in compliance with editorial guidelines. Final version with expanded discussion of the relation between theory and experiments to be published in Nature Communication