741 research outputs found
Systematic comparison of ranking aggregation methods for gene lists in experimental results
MOTIVATION: A common experimental output in biomedical science is a list of genes implicated in a given biological process or disease. The gene lists resulting from a group of studies answering the same, or similar, questions can be combined by ranking aggregation methods to find a consensus or a more reliable answer. Evaluating a ranking aggregation method on a specific type of data before using it is required to support the reliability since the property of a dataset can influence the performance of an algorithm. Such evaluation on gene lists is usually based on a simulated database because of the lack of a known truth for real data. However, simulated datasets tend to be too small compared to experimental data and neglect key features, including heterogeneity of quality, relevance and the inclusion of unranked lists. RESULTS: In this study, a group of existing methods and their variations that are suitable for meta-analysis of gene lists are compared using simulated and real data. Simulated data were used to explore the performance of the aggregation methods as a function of emulating the common scenarios of real genomic data, with various heterogeneity of quality, noise level and a mix of unranked and ranked data using 20 000 possible entities. In addition to the evaluation with simulated data, a comparison using real genomic data on the SARS-CoV-2 virus, cancer (non-small cell lung cancer) and bacteria (macrophage apoptosis) was performed. We summarize the results of our evaluation in a simple flowchart to select a ranking aggregation method, and in an automated implementation using the meta-analysis by information content algorithm to infer heterogeneity of data quality across input datasets. AVAILABILITY AND IMPLEMENTATION: The code for simulated data generation and running edited version of algorithms: https://github.com/baillielab/comparison_of_RA_methods. Code to perform an optimal selection of methods based on the results of this review, using the MAIC algorithm to infer the characteristics of an input dataset, can be downloaded here: https://github.com/baillielab/maic. An online service for running MAIC: https://baillielab.net/maic. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online
Beta relaxation in the shear mechanics of equilibrium viscous liquids: Phenomenology and network modeling of the alpha-beta merging region
The phenomenology of the beta relaxation process in the shear-mechanical
response of glass-forming liquids is summarized and compared to that of the
dielectric beta process. Furthermore, we discuss how to model the observations
by means of standard viscoelastic modeling elements. Necessary physical
requirements to such a model are outlined, and it is argued that physically
relevant models must be additive in the shear compliance of the alpha and beta
parts. A model based on these considerations is proposed and fitted to data for
Polyisobutylene 680.Comment: 8 pages, 6 figures, Minor correction
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measurements of the growth of structure and expansion rate at z=0.57 from anisotropic clustering
We analyze the anisotropic clustering of massive galaxies from the Sloan
Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data
Release 9 (DR9) sample, which consists of 264,283 galaxies in the redshift
range 0.43 < z < 0.7 spanning 3,275 square degrees. Both peculiar velocities
and errors in the assumed redshift-distance relation ("Alcock-Paczynski
effect") generate correlations between clustering amplitude and orientation
with respect to the line-of-sight. Together with the sharp baryon acoustic
oscillation (BAO) standard ruler, our measurements of the broadband shape of
the monopole and quadrupole correlation functions simultaneously constrain the
comoving angular diameter distance (2190 +/- 61 Mpc) to z=0.57, the Hubble
expansion rate at z=0.57 (92.4 +/- 4.5 km/s/Mpc), and the growth rate of
structure at that same redshift (d sigma8/d ln a = 0.43 +/- 0.069). Our
analysis provides the best current direct determination of both DA and H in
galaxy clustering data using this technique. If we further assume a LCDM
expansion history, our growth constraint tightens to d sigma8/d ln a = 0.415
+/- 0.034. In combination with the cosmic microwave background, our
measurements of DA, H, and growth all separately require dark energy at z >
0.57, and when combined imply \Omega_{\Lambda} = 0.74 +/- 0.016, independent of
the Universe's evolution at z<0.57. In our companion paper (Samushia et al.
prep), we explore further cosmological implications of these observations.Comment: 19 pages, 11 figures, submitted to MNRAS, comments welcom
Scale dependence of the primordial spectrum from combining the three-year WMAP, Galaxy Clustering, Supernovae, and Lyman-alpha forests
We probe the scale dependence of the primordial spectrum in the light of the
three-year WMAP (WMAP3) alone and WMAP3 in combination with the other
cosmological observations such as galaxy clustering and Type Ia Supernova
(SNIa). We pay particular attention to the combination with the Lyman
(Ly) forest. Different from the first-year WMAP (WMAP1), WMAP3's
preference on the running of the scalar spectral index on the large scales is
now fairly independent of the low CMB multipoles . A combination with the
galaxy power spectrum from the Sloan Digital Sky Survey (SDSS) prefers a
negative running to larger than 2, regardless the presence of low
CMB () or not. On the other hand if we focus on the
Power Law CDM cosmology with only six parameters (matter density
, baryon density , Hubble Constant , optical
depth , the spectral index, , and the amplitude, , of the
scalar perturbation spectrum) when we drop the low CMB contributions
WMAP3 is consistent with the Harrison-Zel'dovich-Peebles scale-invariant
spectrum ( and no tensor contributions) at . When assuming
a simple power law primordial spectral index or a constant running, in case one
drops the low contributions () WMAP3 is consistent
with the other observations better, such as the inferred value of .
We also find, using a spectral shape with a minimal extension of the running
spectral index model, LUQAS CROFT Ly and SDSS Ly exhibit
somewhat different preference on the spectral shape.Comment: 16 pages, 13 figures Revtex
Perioperative nursing: maintaining momentum and staying safe.
Perioperative practice underpins one of the key activities of many healthcare services but the work of perioperative nurses is little known. A better understanding of their work is important to enable articulation of their contribution to clinical practice. This study observed the practice of perioperative nurses and explored how they described their role. Using ethnographic observation and interview, eighty-five hours observation of eleven nurses were undertaken and eight nurses were interviewed. Thematic analysis was undertaken enabling themes to emerge with two being identified. The first, 'maintaining momentum', described the need to keep people and equipment moving. The second, ‘accounting for safety’, referred to the need to keep the patient safe during this dangerous period. Tension between these two phenomena was apparent. Perioperative nurses describe one of their key roles as maintaining the momentum of the patient’s journey through the operating theatre but having to balance this with the need to ensure the patient’s safety. A core component of the perioperative nurse’s work is thus management of the tension between these. This study illuminated how these nurses understand their practice
Back pain reporting in young girls appears to be puberty-related
BACKGROUND: There is a large increase in back pain reporting in the early teens. In no previous study has the prevalence of low back pain been investigated in relation to the onset of puberty. The objective of this study was to establish whether the onset of puberty is associated with back pain reporting in young girls. METHODS: A subsample of 254 girls aged 8–10 years and 165 girls aged 14–16 years from a cross-sectional survey of 481 children aged 8–10 years and 325 adolescents aged 14–16 years of both sexes. Main outcome measures were back pain defined as low back pain, mid back pain, and/or neck pain in the past month. Other variables of interest were Puberty (five different stages), age, body mass index, and smoking. Independent information on onset of puberty was obtained through a physical examination and on back pain through an individual structured interview. The association was studied between onset of puberty and the outcome variable (the one month period prevalence of back pain), controlling for overweight, and smoking. Odds ratios with 95% confidence intervals were used to describe bivariate associations, logistic regression with robust standard errors was used for multivariate analyses. RESULTS: There is a highly significant trend for increased back pain reporting with increasing level of puberty until maturity is reached. The biggest leap appears between the second level (beginning of puberty) and the third level (mid puberty) and the findings remain after controlling for the covariates. These results emanate from the low back, whereas pain in the mid back and neck do not seem to be linked with pubertal stage. CONCLUSION: In girls, the reporting of low back pain increases in frequency during puberty until maturity, regardless of age. Why some girls are susceptible to back pain in the early stage of puberty is unknown
Provision of aquatic ecosystem services as a consequence of societal changes: The case of the Baltic Sea
Aquatic ecosystem services are important for human wellbeing, but they are much less studied than terrestrial ecosystem services. The objectives of this study are to broaden, itemize and exemplify the human-nature interactions in modeling the future provision of aquatic ecosystem services. We include shared socioeconomic and representative concentration pathways, used extensively in climate research, as drivers of change for the future development of the Baltic Sea. Then we use biogeochemical and ecosystem models to demonstrate the future development of exemplary supporting, provisioning and cultural ecosystem services for two distinct combinations of regionally downscaled global climate and socioeconomic futures. According to the model simulations, the two global futures ("Sustainable well-being" vs. "Fossil-fuelled development") studied lead to clearly deviating trajectories in the provision of marine ecosystem services. Under the "Sustainable well-being"-scenario primary production decreases by 20%, catches of demersal fish increases and the recreation opportunities increase significantly by the end of the ongoing century. Under the "fossil-fuelled development"-scenario primary production doubles, fisheries focus on less valued pelagic fish and the recreation possibilities will decrease. Long-term projections of aquatic ecosystem services prepared for alternative global socioeconomic futures can be used by policy makers and managers to adaptively and iteratively adjust mitigation and adaptation effort with plausible future changes in the drivers of water pollution.Peer reviewe
Sonographic Evaluation of Breast Nodules: Comparison of Conventional, Real-Time Compound, and Pulse-Inversion Harmonic Images
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Analysis of potential systematics
We analyze the density field of galaxies observed by the Sloan Digital Sky
Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) included in
the SDSS Data Release Nine (DR9). DR9 includes spectroscopic redshifts for over
400,000 galaxies spread over a footprint of 3,275 deg^2. We identify,
characterize, and mitigate the impact of sources of systematic uncertainty on
large-scale clustering measurements, both for angular moments of the
redshift-space correlation function and the spherically averaged power
spectrum, P(k), in order to ensure that robust cosmological constraints will be
obtained from these data. A correlation between the projected density of stars
and the higher redshift (0.43 < z < 0.7) galaxy sample (the `CMASS' sample) due
to imaging systematics imparts a systematic error that is larger than the
statistical error of the clustering measurements at scales s > 120h^-1Mpc or k
< 0.01hMpc^-1. We find that these errors can be ameliorated by weighting
galaxies based on their surface brightness and the local stellar density. We
use mock galaxy catalogs that simulate the CMASS selection function to
determine that randomly selecting galaxy redshifts in order to simulate the
radial selection function of a random sample imparts the least systematic error
on correlation function measurements and that this systematic error is
negligible for the spherically averaged correlation function. The methods we
recommend for the calculation of clustering measurements using the CMASS sample
are adopted in companion papers that locate the position of the baryon acoustic
oscillation feature (Anderson et al. 2012), constrain cosmological models using
the full shape of the correlation function (Sanchez et al. 2012), and measure
the rate of structure growth (Reid et al. 2012). (abridged)Comment: Matches version accepted by MNRAS. Clarifications and references have
been added. See companion papers that share the "The clustering of galaxies
in the SDSS-III Baryon Oscillation Spectroscopic Survey:" titl
- …