Showing papers by "Durham University published in 2005"
TL;DR: It is shown that baryon-induced features in the initial conditions of the Universe are reflected in distorted form in the low-redshift galaxy distribution, an effect that can be used to constrain the nature of dark energy with future generations of observational surveys of galaxies.
Abstract: The cold dark matter model has become the leading theoretical picture for the formation of structure in the Universe. This model, together with the theory of cosmic inflation, makes a clear prediction for the initial conditions for structure formation and predicts that structures grow hierarchically through gravitational instability. Testing this model requires that the precise measurements delivered by galaxy surveys can be compared to robust and equally precise theoretical calculations. Here we present a simulation of the growth of dark matter structure using 2,1603 particles, following them from redshift z = 127 to the present in a cube-shaped region 2.230 billion lightyears on a side. In postprocessing, we also follow the formation and evolution of the galaxies and quasars. We show that baryon-induced features in the initial conditions of the Universe are reflected in distorted form in the low-redshift galaxy distribution, an effect that can be used to constrain the nature of dark energy with future generations of observational surveys of galaxies.
4,814 citations
TL;DR: In this article, a new implementation of the Durham semi-analytic model in which feedback due to active galactic nuclei (AGN) is assumed to quench cooling flows in massive halos is discussed.
Abstract: Recent observations of the distant Universe suggest that much of the stellar mass of bright galaxies was already in place at $z>1$. This presents a challenge for models of galaxy formation because massive halos are assembled late in hierarchical cosmologies such as cold dark matter (CDM). In this paper, we discuss a new implementation of the Durham semi-analytic model in which feedback due to active galactic nuclei (AGN) is assumed to quench cooling flows in massive halos. This mechanism naturally creates a break in the local galaxy luminosity function at bright magnitudes. The model is implemented within the Millennium N-body simulation; the accurate dark matter merger trees and large number of realizations of the galaxy formation process that the simulation provides results in highly accurate statistics. After adjusting the values of the physical parameters in the model by reference to the properties of local galaxies, we use it to investigate the evolution of the K-band luminosity and galaxy stellar mass functions. We also calculate the volume averaged star formation rate density of the Universe as a function of redshift and the way in which this is apportioned amongst galaxies of different mass. The model robustly predicts a substantial population of massive galaxies out to redshift $z\sim 5$ and a star formation rate density which rises with increasing redshift in objects of all masses. Although observational data on these properties have been cited as evidence for ``anti-hierarchical'' galaxy formation, we find that when AGN feedback is taken into account, the fundamentally hierachical CDM model provides a very good match to these observations.
2,115 citations
Durham University1, University of Edinburgh2, ETH Zurich3, Johns Hopkins University4, Queen's University5, Liverpool John Moores University6, University of New South Wales7, Rutherford Appleton Laboratory8, University of Bristol9, Australian National University10, University of Cambridge11, California Institute of Technology12, Australia Telescope National Facility13, University College London14, University of Nottingham15
TL;DR: In this paper, a power-spectrum analysis of the final 2DF Galaxy Redshift Survey (2dFGRS) employing a direct Fourier method is presented, and the covariance matrix is determined using two different approaches to the construction of mock surveys, which are used to demonstrate that the input cosmological model can be correctly recovered.
Abstract: We present a power-spectrum analysis of the final 2dF Galaxy Redshift Survey (2dFGRS), employing a direct Fourier method. The sample used comprises 221 414 galaxies with measured redshifts. We investigate in detail the modelling of the sample selection, improving on previous treatments in a number of respects. A new angular mask is derived, based on revisions to the photometric calibration. The redshift selection function is determined by dividing the survey according to rest-frame colour, and deducing a self-consistent treatment of k-corrections and evolution for each population. The covariance matrix for the power-spectrum estimates is determined using two different approaches to the construction of mock surveys, which are used to demonstrate that the input cosmological model can be correctly recovered. We discuss in detail the possible differences between the galaxy and mass power spectra, and treat these using simulations, analytic models and a hybrid empirical approach. Based on these investigations, we are confident that the 2dFGRS power spectrum can be used to infer the matter content of the universe. On large scales, our estimated power spectrum shows evidence for the ‘baryon oscillations’ that are predicted in cold dark matter (CDM) models. Fitting to a CDM model, assuming a primordial n s = 1 spectrum, h = 0.72 and negligible neutrino mass, the preferred
1,940 citations
TL;DR: A model in which the activity of UPR signaling pathways reflects the biosynthetic activity of the ER is proposed, which shows that this information is integrated into control of cellular events, which were previously not considered to be under control of ER signaling pathways.
Abstract: Conformational diseases are caused by mutations altering the folding pathway or final conformation of a protein. Many conformational diseases are caused by mutations in secretory proteins and reach from metabolic diseases, e.g. diabetes, to developmental and neurological diseases, e.g. Alzheimer's disease. Expression of mutant proteins disrupts protein folding in the endoplasmic reticulum (ER), causes ER stress, and activates a signaling network called the unfolded protein response (UPR). The UPR increases the biosynthetic capacity of the secretory pathway through upregulation of ER chaperone and foldase expression. In addition, the UPR decreases the biosynthetic burden of the secretory pathway by downregulating expression of genes encoding secreted proteins. Here we review our current understanding of how an unfolded protein signal is generated, sensed, transmitted across the ER membrane, and how downstream events in this stress response are regulated. We propose a model in which the activity of UPR signaling pathways reflects the biosynthetic activity of the ER. We summarize data that shows that this information is integrated into control of cellular events, which were previously not considered to be under control of ER signaling pathways, e.g. execution of differentiation and starvation programs.
1,697 citations
TL;DR: In this paper, a power spectrum analysis of the final 2dF Galaxy Redshift Survey is presented, employing a direct Fourier method, and the covariance matrix for the power-spectrum estimates is determined using two different approaches to the construction of mock surveys.
Abstract: We present a power spectrum analysis of the final 2dF Galaxy Redshift Survey, employing a direct Fourier method. The sample used comprises 221,414 galaxies with measured redshifts. We investigate in detail the modelling of the sample selection. A new angular mask is derived, based on revisions to the photometric calibration. The redshift selection function is determined by dividing the survey according to rest-frame colour, and deducing a self-consistent treatment of k-corrections and evolution for each population. The covariance matrix for the power-spectrum estimates is determined using two different approaches to the construction of mock surveys which are used to demonstrate that the input cosmological model can be correctly recovered. We are confident that the 2dFGRS power spectrum can be used to infer the matter content of the universe. On large scales, our estimated power spectrum shows evidence for the `baryon oscillations' that are predicted in CDM models. Fitting to a CDM model, assuming a primordial $n_{s}=1$ spectrum, $h=0.72$ and negligible neutrino mass, the preferred parameters are $\Omega_{M} h = 0.168 \pm 0.016$ and a baryon fraction $\Omega_{b} /\Omega_{M} = 0.185\pm0.046$ (1$\sigma$ errors). The value of $\Omega_{M} h$ is $1\sigma$ lower than the $0.20 \pm 0.03$ in our 2001 analysis of the partially complete 2dFGRS. This shift is largely due to the signal from the newly-sampled regions of space, rather than the refinements in the treatment of observational selection. This analysis therefore implies a density significantly below the standard $\Omega_{M} =0.3$: in combination with CMB data from WMAP, we infer $\Omega_{M} =0.231\pm 0.021$. (Abridged.)
1,516 citations
TL;DR: In this paper, an overview of what the authors believe to be every empirical research article into the linkages between HRM and performance published in pre-eminent international refereed journals between 1994 and 2003 is presented.
Abstract: This is an overview of what the authors believe to be every empirical research article into the linkages between HRM and performance published in pre-eminent international refereed journals between 1994 and 2003. The analysis covers the design of the study, including the primary level of analysis and the identity of the respondents; the dominant theoretical framework(s) informing the article; how HRM is conceived and operationalised; how performance is conceived and operationalised; and which control and/or contingency variables are incorporated. Finally, the article examines how each study depicts the so-called 'black box' stage between HRM and performance. It reports wide disparities in the treatment of these components, but also some welcome commonalities and indicative trends that point towards a gradual convergence on how future research into this complex relationship might usefully be conducted. The findings are compared with previous reviews of the literature. The analysis should illuminate the ongoing debate about the linkages between HRM and performance, and prove valuable for future research designs.
1,475 citations
Abstract: We have obtained spectroscopic redshifts using the Keck I telescope for a sample of 73 submillimeter galaxies (SMGs), with a median 850 μm flux density of 5.7 mJy, for which precise positions are available through their faint radio emission. The galaxies lie at redshifts out to z = 3.6, with a median redshift of 2.2 and an interquartile range z = 1.7-2.8. Modeling a purely submillimeter flux-limited sample, based on the expected selection function for our radio-identified sample, suggests a median redshift of 2.3, with a redshift distribution remarkably similar to the optically and radio-selected quasars. The observed redshift distributions are similar for the active galactic nucleus (AGN) and starburst subsamples. The median RAB is 24.6 for the sample. However, the dust-corrected ultraviolet (UV) luminosities of the galaxies rarely hint at the huge bolometric luminosities indicated by their radio/submillimeter emission, with the effect that the true luminosity can be underestimated by a median factor of ~120 for SMGs with pure starburst spectra. Radio and submillimeter observations are thus essential to select the most luminous high-redshift galaxies. The 850 μm, radio, and redshift data are used to estimate the dust temperatures and characterize photometric redshifts. Using 450 μm measurements for a subset of our sample, we confirm that a median dust temperature of Td = 36 ± 7 K, derived on the assumption that the local far-infrared (FIR)-radio correlation applies at high redshift, is reasonable. Individual 450 μm detections are consistent with the local radio-FIR relation holding at z ~ 2. This median Td is lower than that estimated for similarly luminous IRAS 60 μm galaxies locally. We demonstrate that dust temperature variations make it impossible to estimate redshifts for individual SGMs to better than Δz 1 using simple long-wavelength photometric methods. We calculate total infrared and bolometric luminosities (the median infrared luminosity estimated from the radio is 8.5 × 1012 L☉), construct a luminosity function, and quantify the strong evolution of the submillimeter population across z = 0.5-3.5 relative to local IRAS galaxies. We use the bolometric luminosities and UV-spectral classifications to determine a lower limit to the AGN content of the population and measure directly the varying the contribution of highly obscured, luminous galaxies to the luminosity density history of the universe for the first time. We conclude that bright submillimeter galaxies contribute a comparable star formation density to Lyman break galaxies at z = 2-3, and including galaxies below our submillimeter flux limit, this population may be the dominant site of massive star formation at this epoch. The rapid evolution of SMGs and QSO populations contrasts with that seen in bolometrically lower luminosity galaxy samples selected in the rest-frame UV and suggests a close link between SMGs and the formation and evolution of the galactic halos that host QSOs.
1,335 citations
TL;DR: In this article, the authors build on earlier work by Meyer and Land (2003) which introduced the generative notion of threshold concepts within (and across) disciplines, in the sense of transforming the internal view of subject matter or part thereof.
Abstract: The present study builds on earlier work by Meyer and Land (2003) which introduced the generative notion of threshold concepts within (and across) disciplines, in the sense of transforming the internal view of subject matter or part thereof. In this earlier work such concepts were further linked to forms of knowledge that are ‘troublesome’, after the work of Perkins (1999). It was argued that these twinned sets of ideas may define critical moments of irreversible conceptual transformation in the educational experiences of learners, and their teachers. The present study aims (a) to examine the extent to which such phenomena can be located within personal understandings of discipline-specific epistemological discourses, (b) to develop more extensively notions of liminality within learning that were raised in the first paper, and (c) to propose a conceptual framework within which teachers may advance their own reflective practice.
1,260 citations
TL;DR: Using a neuromuscular training program may have a direct benefit in decreasing the number of anterior cruciate ligament injuries in female soccer players.
Abstract: Background: Among female athletes it has not been established whether a neuromuscular and proprioceptive sports-specific training program will consistently reduce the incidence of anterior cruciate ligament injuries.Purpose: To determine whether a neuromuscular and proprioceptive performance program was effective in decreasing the incidence of anterior cruciate ligament injury within a select population of competitive female youth soccer players.Study Design: Cohort study; Level of evidence, 2.Methods: In 2000, 1041 female subjects from 52 teams received a sports-specific training intervention in a prospective non-randomized trial. The control group consisted of the remaining 1905 female soccer players from 95 teams participating in the same league who were age and skill matched. In the 2001 season, 844 female athletes from 45 teams were enrolled in the study, with 1913 female athletes (from 112 teams) serving as the age- and skill-matched controls. All subjects were female soccer players between the ages...
1,070 citations
TL;DR: With 64% of cancer patients surviving > 5 years beyond diagnosis, oncologists are challenged to expand their focus from acute care to managing the long-term health consequences of cancer.
Abstract: Purpose Cancer survivors are at increased risk for several comorbid conditions, and many seek lifestyle change to reduce dysfunction and improve long-term health. To better understand the impact of cancer on adult survivors' health and health behaviors, a review was conducted to determine (1) prevalent physical health conditions, (2) persistent lifestyle changes, and (3) outcomes of previous lifestyle interventions aimed at improving health within this population. Methods Relevant studies from 1966 and beyond were identified through MEDLINE and PubMed searches. Results Cancer survivors are at increased risk for progressive disease but also for second primaries, osteoporosis, obesity, cardiovascular disease, diabetes, and functional decline. To improve overall health, survivors frequently initiate diet, exercise, and other lifestyle changes after diagnosis. However, those who are male, older, and less educated are less likely to adopt these changes. There also is selective uptake of messages, as evidenced ...
1,051 citations
TL;DR: In this paper, the authors use a multilevel governance perspective to examine the discursive and material struggles which take place in creating sustainable cities and find that the interpretation and implementation of sustainability are shaped by forms of governance which stretch across geographical scales and beyond the boundary of the urban.
Abstract: While sustainable cities have been promoted as a desirable goal within a variety of policy contexts, critical questions concerning the extent to which cities and local governments can address the challenges of sustainability remain unanswered. We use a multilevel governance perspective to examine the discursive and material struggles which take place in creating sustainable cities. In exploring the politics of implementing climate protection through development planning in Newcastle upon Tyne and transport planning in Cambridgeshire, we find that the interpretation and implementation of sustainability are shaped by forms of governance which stretch across geographical scales and beyond the boundary of the urban. We argue that the 'urban' governance of climate protection involves relations between levels of the state and new network spheres of authority which challenge traditional distinctions between local, national and global environmental politics.
TL;DR: Martelli et al. as discussed by the authors traced the origins and growth of scenarios and the subsequent evolution of various methodologies; a classification of the methodologies into three main schools of techniques is given and the salient features of these schools are compared and contrasted.
TL;DR: In this paper, a new spatial grammar of environmental governance must be sensitive to both the politics of scale and the power of networks, rather than considering scalar and non-scalar interpretations of spatiality as necessarily opposite.
TL;DR: These guidelines update previous guidance published in 2005 and have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology and others.
Abstract: These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.
TL;DR: In this article, a review of the light-emitting properties of conjugated polymers is presented, with a focus on the application of polythiophenes as electroluminescent materials.
Abstract: Polythiophenes are one of the most important classes of conjugated polymers, with a wide range of applications, such as conducting films, electrochromics, and field-effect transistors, which have been the subject of a number of older and more recent reviews. Much less attention has been paid to the light-emitting properties of this class of materials, although their unique properties present a number of opportunities unavailable from more popular polymeric light emitters such as polyfluorene or poly(p-phenylene vinylene). This article reviews achievements to date in applications of thiophene-based polymers and oligomers as electroluminescent materials. We demonstrate the basic principles of controlling the optical properties of polythiophenes through structural modifications and review the most important light-emitting materials created from thiophene derivatives. Special attention is paid to consequences of structural variations on the performance of light-emitting diodes fabricated with these materials.
TL;DR: In this paper, the authors examined the contribution of central and satellite galaxies to the HOD, more specifically to the probability P(N|M) that a halo of virial mass M contains N galaxies of a particular class.
Abstract: The halo occupation distribution (HOD) describes the relation between galaxies and dark matter at the level of individual dark matter halos. The properties of galaxies residing at the centers of halos differ from those of satellite galaxies because of differences in their formation histories. Using a smoothed particle hydrodynamics (SPH) simulation and a semianalytic (SA) galaxy formation model, we examine the separate contributions of central and satellite galaxies to the HOD, more specifically to the probability P(N|M) that a halo of virial mass M contains N galaxies of a particular class. In agreement with earlier results for dark matter subhalos, we find that the mean occupation function langNrangM for galaxies above a baryonic mass threshold can be approximated by a step function for central galaxies plus a power law for satellites and that the distribution of satellite numbers is close to Poisson at fixed halo mass. Since the number of central galaxies is always zero or one, the width of P(N|M) is narrower than a Poisson distribution at low N and approaches Poisson at high N. For galaxy samples defined by different baryonic mass thresholds, there is a nearly linear relation between the minimum halo mass Mmin required to host a central galaxy and the mass M1 at which an average halo hosts one satellite, with M1 ≈ 14Mmin (SPH) or M1 ≈ 18Mmin (SA). The stellar population age of central galaxies correlates with halo mass, and this correlation explains much of the age dependence of the galaxy HOD. The mean occupation number of young galaxies exhibits a local minimum at M ~ 10Mmin where halos are too massive to host a young central galaxy but not massive enough to host satellites. Using the SA model, we show that the conditional galaxy mass function at fixed halo mass cannot be described by a Schechter function because central galaxies produce a "bump" at high masses. We suggest parameterizations for the HOD and the conditional luminosity function that can be used to model observed galaxy clustering. Many of our predictions are in good agreement with recent results inferred from clustering in the Sloan Digital Sky Survey.
TL;DR: In this paper, the authors developed a paddy rice mapping algorithm that uses time series of three vegetation indices (LSWI, EVI, and NDVI) derived from MODIS images to identify that initial period of flooding and transplanting in paddy Rice fields, based on the sensitivity of LSWI to the increased surface moisture during the period flooding and rice transplanting.
TL;DR: Clinical trials are needed to define whether hyporesponders to clopidogrel are at increased risk for thrombotic events and whether hyper-responders are at increase risk for bleeding.
TL;DR: Analysis of mitochondrial DNA sequences from 686 wild and domestic pig specimens reveals multiple centers of domestication across Eurasia and that European, rather than Near Eastern, wild boar are the principal source of modern European domestic pigs.
Abstract: Mitochondrial DNA (mtDNA) sequences from 686 wild and domestic pig specimens place the origin of wild boar in island Southeast Asia (ISEA), where they dispersed across Eurasia. Previous morphological and genetic evidence suggested pig domestication took place in a limited number of locations (principally the Near East and Far East). In contrast, new genetic data reveal multiple centers of domestication across Eurasia and that European, rather than Near Eastern, wild boar are the principal source of modern European domestic pigs.
01 Jan 2005
TL;DR: In this paper, the authors developed a paddy rice mapping algorithm that uses time series of three vegetation indices (LSWI, EVI, and NDVI) derived from MODIS images to identify that initial period of flooding and transplanting in paddy Rice fields, based on the sensitivity of LSWI to the increased surface moisture during the period flooding and rice transplanting.
Abstract: Information on the area and spatial distribution of paddy rice fields is needed for trace gas emission estimates, management of water resources, and food security. Paddy rice fields are characterized by an initial period of flooding and transplanting, during which period open canopy (a mixture of surface water and rice crops) exists. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the NASA EOS Terra satellite has visible, near infrared and shortwave infrared bands; and therefore, a number of vegetation indices can be calculated, including Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI) that is sensitive to leaf water and soil moisture. In this study, we developed a paddy rice mapping algorithm that uses time series of three vegetation indices (LSWI, EVI, and NDVI) derived from MODIS images to identify that initial period of flooding and transplanting in paddy rice fields, based on the sensitivity of LSWI to the increased surface moisture during the period of flooding and rice transplanting. We ran the algorithm to map paddy rice fields in 13 provinces of southern China, using the 8-day composite MODIS Surface Reflectance products (500-m spatial resolution) in 2002. The resultant MODIS-derived paddy rice map was evaluated, using the National Land Cover Dataset (1: 100,000 scale) derived from analysis of Landsat ETM+ images in 1999/2000. There were reasonable agreements in area estimates of paddy rice fields between the MODIS-derived map and the Landsat-based dataset at the provincial and county levels. The results of this study indicated that the MODIS-based paddy rice mapping algorithm could potentially be applied at large spatial scales to monitor paddy rice agriculture on a timely and frequent basis. (c) 2005 Elsevier Inc. All rights reserved.
TL;DR: In this article, the abundance of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) in the Λ cold dark matter cosmology was predicted, based on the self-consistent calculation of the absorption and emission of radiation by dust.
Abstract: We present predictions for the abundance of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) in the Λ cold dark matter cosmology. A key feature of our model is the self-consistent calculation of the absorption and emission of radiation by dust. The new model successfully matches the LBG luminosity function, as well as reproducing the properties of the local galaxy population in the optical and infrared. The model can also explain the observed galaxy number counts at 850 μm, but only if we assume a top-heavy initial mass function for the stars formed in bursts. The predicted redshift distribution of SMGs depends relatively little on their flux over the range 1–10 mJy, with a median value of z≈ 2.0 at a flux of 5 mJy, in good agreement with the recent measurement by Chapman et al. The counts of SMGs are predicted to be dominated by ongoing starbursts. However, in the model these bursts are responsible for making only a few per cent of the stellar mass locked up in massive ellipticals at the present day.
TL;DR: Trial-based cost-effectiveness studies have appeal because of their high internal validity and timeliness and improving the quality and uniformity of these studies will increase their value to decision makers who consider evidence of economic value along with clinical efficacy when making resource allocation decisions.
TL;DR: The use of high internal phase emulsions as templates to create highly porous materials (PolyHIPEs) is described in this article, where the void fraction is very high and can reach levels of 0.99.
TL;DR: The results indicate that unprocessed prelamin A and truncated lamin A act dominant negatively to perturb DNA damage response and repair, resulting in genomic instability which might contribute to laminopathy-based premature aging.
Abstract: Premature aging syndromes often result from mutations in nuclear proteins involved in the maintenance of genomic integrity. Lamin A is a major component of the nuclear lamina and nuclear skeleton. Truncation in lamin A causes Hutchinson-Gilford progerial syndrome (HGPS), a severe form of early-onset premature aging. Lack of functional Zmpste24, a metalloproteinase responsible for the maturation of prelamin A, also results in progeroid phenotypes in mice and humans. We found that Zmpste24-deficient mouse embryonic fibroblasts (MEFs) show increased DNA damage and chromosome aberrations and are more sensitive to DNA-damaging agents. Bone marrow cells isolated from Zmpste24−/− mice show increased aneuploidy and the mice are more sensitive to DNA-damaging agents. Recruitment of p53 binding protein 1 (53BP1) and Rad51 to sites of DNA lesion is impaired in Zmpste24−/− MEFs and in HGPS fibroblasts, resulting in delayed checkpoint response and defective DNA repair. Wild-type MEFs ectopically expressing unprocessible prelamin A show similar defects in checkpoint response and DNA repair. Our results indicate that unprocessed prelamin A and truncated lamin A act dominant negatively to perturb DNA damage response and repair, resulting in genomic instability which might contribute to laminopathy-based premature aging.
TL;DR: The GUSTO bleeding classification identifies patients who are at risk for short- and long-term adverse events and Therapies that minimize bleeding risk and maintain an anticoagulant effect may improve outcomes among patients who have ACS.
Abstract: Bleeding is a complication of current therapies for acute coronary syndrome (ACS). No studies have examined the effect of bleeding events on clinical outcomes. We analyzed pooled data from 4 multicenter, randomized clinical trials of patients who had ACS (n = 26,452) to determine an association between bleeding severity as measured by the GUSTO scale and 30-day and 6-month mortality rates using Cox proportional hazards modeling that incorporated bleeding as a time-dependent covariate. The analysis was repeated to examine procedure- and non–procedure-related bleeding and after censoring at the time of coronary artery bypass grafting. Of all the patients included, 27.6% had ≥1 bleeding episode. Patients who bled were older and sicker at presentation than were those who did not bleed. Unadjusted rates of 30-day and 6-month mortality increased as bleeding severity increased. There were stepwise increases in the adjusted hazards of 30-day mortality (mild bleeding, hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3 to 1.9; moderate bleeding, HR 2.7, 95% CI l 2.3 to 3.4; severe bleeding, HR 10.6, 95% CI 8.3 to 13.6) and 6-month mortality (mild bleeding, HR 1.4, 95% CI 1.2 to 1.6; moderate bleeding, HR 2.1, 95% CI 1.8 to 2.4; severe bleeding, HR 7.5, 95% CI 6.1 to 9.3) as bleeding severity increased. Results were consistent after censoring for coronary artery bypass grafting and for procedure- and non–procedure-related bleeds. In conclusion, the GUSTO bleeding classification identifies patients who are at risk for short- and long-term adverse events. Therapies that minimize bleeding risk and maintain an anticoagulant effect may improve outcomes among patients who have ACS.
TL;DR: In this article, a brief overview of organic electroluminescence and electrophosphorescence is provided, and a more detailed consideration of ways in which electron transport in these systems has been enhanced by the incorporation of electron-deficient small molecules and polymers into the devices, either as blends or by covalent attachment of sub-units to the luminophore or as an additional electron-transporting, hole-blocking (ETHB) layer adjacent to the cathode.
Abstract: One of the requirements for efficient organic electroluminescent devices (OLEDs) is balanced charge injection from the two electrodes and efficient transport of both holes and electrons within the luminescent layer in the device structure. Many of the common luminescent conjugated polymers, e.g. derivatives of poly(phenylenevinylene) and poly(fluorene), are predominantly hole transporters (i.e. p-dopable). This article gives a brief overview of organic electroluminescence and electrophosphorescence and provides a more detailed consideration of ways in which electron transport in these systems has been enhanced by the incorporation of electron-deficient (i.e. n-dopable) small molecules and polymers into the devices, either as blends or by covalent attachment of sub-units to the luminophore or as an additional electron-transporting, hole-blocking (ETHB) layer adjacent to the cathode. The chemical structures of these systems are presented and their roles are assessed. Most of these ETHB molecules are electron-deficient aromatic nitrogen-containing heterocycles, e.g. derivatives of 1,3,4-oxadiazole, pyridine, pyrimidine, pyrazine, quinoline, etc. Non-aromatic thiophene-S,S-dioxide derivatives are also discussed. The article is written from an organic chemist's perspective.
TL;DR: Outcome (resolution, multiple organ dysfunction syndrome or death) is dependent on the balance of SIRS and such compensatory mechanisms, and directed therapies have been successful to date in influencing outcome.
Abstract: Background Localized inflammation is a physiological protective response which is generally tightly controlled by the body at the site of injury. Loss of this local control or an overly activated response results in an exaggerated systemic response which is clinically identified as systemic inflammatory response syndrome (SIRS). Compensatory mechanisms are initiated in concert with SIRS and outcome (resolution, multiple organ dysfunction syndrome or death) is dependent on the balance of SIRS and such compensatory mechanisms. No directed therapies have been successful to date in influencing outcome.
Method This review examines the current spectrum and pathophysiology of SIRS.
Results and conclusion Further clinical and basic scientific research is required to develop the global picture of SIRS, its associated family of syndromes and their natural histories.
TL;DR: In this paper, the authors presented an improved calculation of light pseudoscalar form factors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading-order twist-4 corrections.
Abstract: We present an improved calculation of $B\ensuremath{\rightarrow}$ light pseudoscalar form factors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading-order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is 10 to 13% and can be improved, at least in part, by reducing the uncertainty of hadronic input parameters, in particular, those describing the twist-2 distribution amplitudes of the $\ensuremath{\pi}$, $K$, and $\ensuremath{\eta}$. We present our results in a way which details the dependence of the form factors on these parameters and facilitates the incorporation of future updates of their values from, e.g., lattice calculations.
TL;DR: In this article, the authors present results from an IRAM Plateau de Bure millimetre-wave Interferometer (PdBI) survey for carbon monoxide (CO) emission towards radio-detected submillimetre galaxies (SMGs) with known optical and near-infrared spectroscopic redshifts.
Abstract: In this paper, we present results from an Institut de Radio Astronomie Millimetrique (IRAM) Plateau de Bure millimetre-wave Interferometer (PdBI) survey for carbon monoxide (CO) emission towards radio-detected submillimetre galaxies (SMGs) with known optical and near-infrared spectroscopic redshifts. Five sources in the redshift range z ∼ 1-3.5 were detected, nearly doubling the number of SMGs detected in CO. We summarize the properties of all 12 CO-detected SMGs, as well as six sources not detected in CO by our survey, and use this sample to explore the bulk physical properties of the submillimetre galaxy (SMG) population as a whole. The median CO line luminosity of the SMGs is = (3.8 ± 2.0) × 10 10 K km s -1 pc 2 . Using a CO-to-H 2 conversion factor appropriate for starburst galaxies, this corresponds to a molecular gas mass = (3.0 ± 1.6) x 10 10 M ○. within an ∼ 2 kpc radius, approximately 4 times greater than the most luminous local ultraluminous infrared galaxies (ULIRGs) but comparable to that of the most extreme high-redshift radio galaxies (HzRGs) and quasi-sellar objects (QSOs). The median CO FWHM linewidth is broad, (FWHM) = 780 ± 320 km s -1 , and the SMGs often have double-peaked line profiles, indicative of either a merger or a disc. From their median gas reservoirs (∼ 3 x 10 10 M ○. ) and star formation rates (≥ 700 M ○. yr -1 ), we estimate a lower limit on the typical gas-depletion time-scale of ≥ 40 Myr in SMGs. This is marginally below the typical age expected for the starbursts in SMGs and suggests that negative feedback processes may play an important role in prolonging the gas consumption time-scale. We find a statistically significant correlation between the far-infrared and CO luminosities of the SMGs, which extends the observed correlation for local ULIRGs to higher luminosities and higher redshifts. The non-linear nature of the correlation implies that SMGs have higher far-infrared to CO luminosity ratios and possibly higher star formation efficiencies (SFEs), than local ULIRGs. Assuming a typical CO source diameter of θ ∼ 0.5 arcsec (D ∼ 4kpc), we estimate a median dynamical mass of ≃ (1.2 ± 1.5) x 10 11 M ○. for the SMG sample. Both the total gas and stellar masses imply that SMGs are very massive systems, dominated by baryons in their central regions. The baryonic and dynamical properties of these systems mirror those of local giant ellipticals and are consistent with numerical simulations of the formation of the most massive galaxies. We have been able to impose a lower limit of ≥ 5 x 10 -6 Mpc -3 to the comoving number density of massive galaxies in the redshift range z ∼ 2-3.5, which is in agreement with results from recent spectroscopic surveys and the most recent model predictions.
TL;DR: The formulation of the American Meteorological Society (AMS) and U.S. Environmental Protection Agency (EPA) Regulatory Model (AERMOD) Improvement Committee's applied air dispersion model is described in this paper.
Abstract: The formulation of the American Meteorological Society (AMS) and U.S. Environmental Protection Agency (EPA) Regulatory Model (AERMOD) Improvement Committee’s applied air dispersion model is described. This is the first of two articles describing the model and its performance. Part I includes AERMOD’s characterization of the boundary layer with computation of the Monin–Obukhov length, surface friction velocity, surface roughness length, sensible heat flux, convective scaling velocity, and both the shear- and convection-driven mixing heights. These parameters are used in conjunction with meteorological measurements to characterize the vertical structure of the wind, temperature, and turbulence. AERMOD’s method for considering both the vertical inhomogeneity of the meteorological characteristics and the influence of terrain are explained. The model’s concentration estimates are based on a steady-state plume approach with significant improvements over commonly applied regulatory dispersion models. Co...