Showing papers by "York University published in 2011"

A catalog of quasar properties from sloan digital sky survey data release 7

Abstract: We present a compilation of properties of the 105,783 quasars in the Sloan Digital Sky Survey Data Release 7 (DR7) quasar catalog. In this product, we compile continuum and emission line measurements around the Hα, Hβ, Mg II, and C IV regions, as well as other quantities such as radio properties, and flags indicating broad absorption line quasars, disk emitters, etc. We also compile virial black hole mass estimates based on various calibrations. For the fiducial virial mass estimates we use the Vestergaard & Peterson (VP06) calibrations for Hβ and C IV, and our own calibration for Mg II which matches the VP06 Hβ masses on average. We describe the construction of this catalog and discuss its limitations. The catalog and its future updates will be made publicly available online.

Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam

Abstract: The T2K experiment observes indications of nu(mu) -> nu(mu) e appearance in data accumulated with 1.43 x 10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Delta m(23)(2)| = 2.4 x 10(-3) eV(2), sin(2)2 theta(23) = 1 and sin(2)2 theta(13) = 0, the expected number of such events is 1.5 +/- 0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7 x 10(-3), equivalent to 2.5 sigma significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2 theta(13) < 0.28(0.34) for delta(CP) = 0 and a normal (inverted) hierarchy.

The qualitative research interview

Abstract: Purpose – Despite the growing pressure to encourage new ways of thinking about research methodology, only recently have interview methodologists begun to realize that “we cannot lift the results of interviewing out of the contexts in which they were gathered and claim them as objective data with no strings attached”. The purpose of this paper is to provide additional insight based on a critical reflection of the interview as a research method drawing upon Alvesson's discussion from the neopositivist, romanticist and localist interview perspectives. Specifically, the authors focus on critical reflections of three broad categories of a continuum of interview methods: structured, semi‐structured and unstructured interviews.Design/methodology/approach – The authors adopt a critical and reflexive approach to understanding the literature on interviews to develop alternative insights about the use of interviews as a qualitative research method.Findings – After examining the neopositivist (interview as a “tool”) ...

The impact of corporate social responsibility on the cost of bank loans

Abstract: This study examines the link between corporate social responsibility (CSR) and bank debt. Our focus on banks exploits their specialized role as delegated monitors of the firm. Using a sample of 3996 loans to US firms, we find that firms with social responsibility concerns pay between 7 and 18 basis points more than firms that are more responsible. Lenders are more sensitive to CSR concerns in the absence of security. We document a mixed reaction to discretionary CSR investments. Low-quality borrowers that engage in discretionary CSR spending face higher loan spreads and shorter maturities, but lenders are indifferent to CSR investments by high-quality borrowers.

The Cognitive Reflection Test as a predictor of performance on heuristics-and-biases tasks

Abstract: The Cognitive Reflection Test (CRT; Frederick, 2005) is designed to measure the tendency to override a prepotent response alternative that is incorrect and to engage in further reflection that leads to the correct response. In this study, we showed that the CRT is a more potent predictor of performance on a wide sample of tasks from the heuristics-and-biases literature than measures of cognitive ability, thinking dispositions, and executive functioning. Although the CRT has a substantial correlation with cognitive ability, a series of regression analyses indicated that the CRT was a unique predictor of performance on heuristics-and-biases tasks. It accounted for substantial additional variance after the other measures of individual differences had been statistically controlled. We conjecture that this is because neither intelligence tests nor measures of executive functioning assess the tendency toward miserly processing in the way that the CRT does. We argue that the CRT is a particularly potent measure of the tendency toward miserly processing because it is a performance measure rather than a self-report measure.

The Neural Bases of Social Cognition and Story Comprehension

Abstract: A great deal of research exists on the neural basis of theory-of-mind (ToM) or mentalizing. Qualitative reviews on this topic have identified a mentalizing network composed of the medial prefrontal cortex, posterior cingulate/precuneus, and bilateral temporal parietal junction. These conclusions, however, are not based on a quantitative and systematic approach. The current review presents a quantitative meta-analysis of neuroimaging studies pertaining to ToM, using the activation-likelihood estimation (ALE) approach. Separate ALE meta-analyses are presented for story-based and nonstory-based studies of ToM. The conjunction of these two meta-analyses reveals a core mentalizing network that includes areas not typically noted by previous reviews. A third ALE meta-analysis was conducted with respect to story comprehension in order to examine the relation between ToM and stories. Story processing overlapped with many regions of the core mentalizing network, and these shared regions bear some resemblance to a n...

The T2K Experiment

Abstract: The T2K experiment is a long-baseline neutrino oscillation experiment Its main goal is to measure the last unknown lepton sector mixing angle {\theta}_{13} by observing { u}_e appearance in a { u}_{\mu} beam It also aims to make a precision measurement of the known oscillation parameters, {\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via { u}_{\mu} disappearance studies Other goals of the experiment include various neutrino cross section measurements and sterile neutrino searches The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande) located 295 km away from J-PARC This paper provides a comprehensive review of the instrumentation aspect of the T2K experiment and a summary of the vital information for each subsystem

Cardiovascular risk with non-steroidal anti-inflammatory drugs: systematic review of population-based controlled observational studies.

Abstract: Background: Randomised trials have highlighted the cardiovascular risks of non-steroidal anti-inflammatory drugs (NSAIDs) in high doses and sometimes atypical settings. Here, we provide estimates of the comparative risks with individual NSAIDs at typical doses in community settings. Methods and Findings: We performed a systematic review of community-based controlled observational studies. We conducted comprehensive literature searches, extracted adjusted relative risk (RR) estimates, and pooled the estimates for major cardiovascular events associated with use of individual NSAIDs, in different doses, and in populations with low and high background risks of cardiovascular events. We also compared individual drugs in pair-wise (within study) analyses, generating ratios of RRs (RRRs). Thirty case-control studies included 184,946 cardiovascular events, and 21 cohort studies described outcomes in .2.7 million exposed individuals. Of the extensively studied drugs (ten or more studies), the highest overall risks were seen with rofecoxib, 1.45 (95% CI 1.33, 1.59), and diclofenac, 1.40 (1.27, 1.55), and the lowest with ibuprofen, 1.18 (1.11, 1.25), and naproxen, 1.09 (1.02, 1.16). In a sub-set of studies, risk was elevated with low doses of rofecoxib, 1.37 (1.20, 1.57), celecoxib, 1.26 (1.09, 1.47), and diclofenac, 1.22 (1.12, 1.33), and rose in each case with higher doses. Ibuprofen risk was seen only with higher doses. Naproxen was risk-neutral at all doses. Of the less studied drugs etoricoxib, 2.05 (1.45, 2.88), etodolac, 1.55 (1.28, 1.87), and indomethacin, 1.30 (1.19, 1.41), had the highest risks. In pair-wise comparisons, etoricoxib had a higher RR than ibuprofen, RRR=1.68 (99% CI 1.14, 2.49), and naproxen, RRR=1.75 (1.16, 2.64); etodolac was not significantly different from naproxen and ibuprofen. Naproxen had a significantly lower risk than ibuprofen, RRR=0.92 (0.87, 0.99). RR estimates were constant with different background risks for cardiovascular disease and rose early in the course of treatment. Conclusions: This review suggests that among widely used NSAIDs, naproxen and low-dose ibuprofen are least likely to increase cardiovascular risk. Diclofenac in doses available without prescription elevates risk. The data for etoricoxib were sparse, but in pair-wise comparisons this drug had a significantly higher RR than naproxen or ibuprofen. Indomethacin is an older, rather toxic drug, and the evidence on cardiovascular risk casts doubt on its continued clinical use. Please see later in the article for the Editors’ Summary.

The effects of glucocorticoids on adipose tissue lipid metabolism

Abstract: Glucocorticoids (GCs) have long been accepted as being catabolic in nature, liberating energy substrates during times of stress to supply the increased metabolic demand of the body. The effects of GCs on adipose tissue metabolism are conflicting, however, because patients with elevated GCs present with central adiposity. We performed an extensive literature review of the effects of GCs on adipose tissue metabolism. The contradictory effects of GCs on lipid metabolism occur through a number of different mechanisms, some of which are well defined and others remain to be elucidated. Firstly, through increases in caloric and dietary fat intake, along with increased hydrolysis of circulating triglycerides (chylomicrons, very low-density lipoproteins) by lipoprotein lipase activity, GCs increase the amount of fatty acids in circulation, which are then available for ectopic fat distribution (liver, muscle, and central adipocytes). Glucocorticoids also increase de novo lipid production in hepatocytes through increased expression of fatty acid synthase. There is some controversy as to whether these same mechanisms occur in adipocytes, thereby contributing to adipose hypertrophy. Glucocorticoids promote preadipocyte conversion to mature adipocytes, causing hyperplasia of the adipose tissue. Glucocorticoids also have acute antilipolytic effect on adipocytes, whereas their genomic actions facilitate increased lipolysis after about 48 hours of exposure. The acute and long-term effects of GCs on adipose tissue lipolysis remain unclear. Although considerable evidence supports the notion that GCs increase lipolysis through glucocorticoid-induced increases of lipase expression, they clearly have antilipolytic effects within these same tissues and cell line models.

Unification of luminous type 1 quasars through c iv emission

Abstract: Using a sample of ~30,000 quasars from the 7th Data Release of the Sloan Digital Sky Survey, we explore the range of properties exhibited by high-ionization, broad emission lines, such as C IV λ1549. Specifically, we investigate the anti-correlation between continuum luminosity and emission-line equivalent width (the Baldwin Effect (BEff)) and the blueshifting of the high-ionization emission lines with respect to low-ionization emission lines. Employing improved redshift determinations from Hewett & Wild, the blueshift of the C IV emission line is found to be nearly ubiquitous, with a mean shift of ~810 km s–1 for radio-quiet (RQ) quasars and ~360 km s–1 for radio-loud (RL) quasars. The BEff is present in both RQ and RL samples. We consider these phenomena within the context of an accretion disk-wind model that is modulated by the nonlinear correlation between ultraviolet and X-ray continuum luminosity. Composite spectra are constructed as a function of C IV emission-line properties in an attempt to reveal empirical relationships between different line species and the continuum. Within a two-component disk+wind model of the broad emission-line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL quasars are consistent with being dominated by the disk component, while broad absorption line quasars are consistent with being dominated by the wind component. Some RQ objects have emission-line features similar to RL quasars; they may simply have insufficient black hole (BH) spin to form radio jets. Our results suggest that there could be significant systematic errors in the determination of L bol and BH mass that make it difficult to place these findings in a more physical context. However, it is possible to classify quasars in a paradigm where the diversity of BELR parameters is due to differences in an accretion disk wind between quasars (and over time); these differences are underlain primarily by the spectral energy distribution, which ultimately must be tied to BH mass and accretion rate.

Charged-particle multiplicities in pp interactions measured with the ATLAS detector at the LHC

Abstract: Measurements are presented from proton-proton collisions at centre-of-mass energies of root s = 0.9, 2.36 and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections. The results are compared to each other and to various Monte Carlo (MC) models, including a new AMBT1 pythia6 tune. In all the kinematic regions considered, the particle multiplicities are higher than predicted by the MC models. The central charged-particle multiplicity per event and unit of pseudorapidity, for tracks with p(T) > 100 MeV, is measured to be 3.483 +/- 0.009 (stat) +/- 0.106 (syst) at root s = 0.9 TeV and 5.630 +/- 0.003 (stat) +/- 0.169 (syst) at root s = 7 TeV.

Birth of a relativistic outflow in the unusual γ-ray transient Swift J164449.3+573451

Abstract: Active galactic nuclei, which are powered by long-term accretion onto central supermassive black holes, produce relativistic jets with lifetimes of at least one million years, and the observation of the birth of such a jet is therefore unlikely. Transient accretion onto a supermassive black hole, for example through the tidal disruption of a stray star, thus offers a rare opportunity to study the birth of a relativistic jet. On 25 March 2011, an unusual transient source (Swift J164449.3+573451) was found, potentially representing such an accretion event. Here we report observations spanning centimetre to millimetre wavelengths and covering the first month of evolution of a luminous radio transient associated with Swift J164449.3+573451. The radio transient coincides with the nucleus of an inactive galaxy. We conclude that we are seeing a newly formed relativistic outflow, launched by transient accretion onto a million-solar-mass black hole. A relativistic outflow is not predicted in this situation, but we show that the tidal disruption of a star naturally explains the observed high-energy properties and radio luminosity and the inferred rate of such events. The weaker beaming in the radio-frequency spectrum relative to γ-rays or X-rays suggests that radio searches may uncover similar events out to redshifts of z ≈ 6.

Reshaping the mind: The benefits of bilingualism.

Abstract: Studies have shown that bilingual individuals consistently outperform their monolingual counterparts on tasks involving executive control. The present paper reviews some of the evidence for this conclusion and relates the findings to the effect of bilingualism on cognitive organisation and to conceptual issues in the structure of executive control. Evidence for the protective effect of bilingualism against Alzheimer’s disease is presented with some speculation about the reason for that protection.

Crowdsourcing, citizen sensing and sensor web technologies for public and environmental health surveillance and crisis management: trends, OGC standards and application examples

Abstract: 'Wikification of GIS by the masses' is a phrase-term first coined by Kamel Boulos in 2005, two years earlier than Goodchild's term 'Volunteered Geographic Information'. Six years later (2005-2011), OpenStreetMap and Google Earth (GE) are now full-fledged, crowdsourced 'Wikipedias of the Earth' par excellence, with millions of users contributing their own layers to GE, attaching photos, videos, notes and even 3-D (three dimensional) models to locations in GE. From using Twitter in participatory sensing and bicycle-mounted sensors in pervasive environmental sensing, to creating a 100,000-sensor geo-mashup using Semantic Web technology, to the 3-D visualisation of indoor and outdoor surveillance data in real-time and the development of next-generation, collaborative natural user interfaces that will power the spatially-enabled public health and emergency situation rooms of the future, where sensor data and citizen reports can be triaged and acted upon in real-time by distributed teams of professionals, this paper offers a comprehensive state-of-the-art review of the overlapping domains of the Sensor Web, citizen sensing and 'human-in-the-loop sensing' in the era of the Mobile and Social Web, and the roles these domains can play in environmental and public health surveillance and crisis/disaster informatics. We provide an in-depth review of the key issues and trends in these areas, the challenges faced when reasoning and making decisions with real-time crowdsourced data (such as issues of information overload, "noise", misinformation, bias and trust), the core technologies and Open Geospatial Consortium (OGC) standards involved (Sensor Web Enablement and Open GeoSMS), as well as a few outstanding project implementation examples from around the world.

Epidemiology of chronic non-cancer pain in Europe: narrative review of prevalence, pain treatments and pain impact

Abstract: Estimates on the epidemiology of chronic non-cancer pain vary widely throughout Europe. It is unclear whether this variation reflects true population differences or methodological factors. Such epi...

Crowdsourcing, citizen sensing and Sensor Web technologies for public and environmental health surveillance and crisis management: trends, OGC standards and application examples

Abstract: 'Wikification of GIS by the masses' is a phrase-term first coined by Kamel Boulos in 2005, two years earlier than Goodchild's term 'Volunteered Geographic Information'. Six years later (2005-2011), OpenStreetMap and Google Earth (GE) are now full-fledged, crowdsourced 'Wikipedias of the Earth' par excellence, with millions of users contributing their own layers to GE, attaching photos, videos, notes and even 3-D (three dimensional) models to locations in GE. From using Twitter in participatory sensing and bicycle-mounted sensors in pervasive environmental sensing, to creating a 100,000-sensor geo-mashup using Semantic Web technology, to the 3-D visualisation of indoor and outdoor surveillance data in real-time and the development of next-generation, collaborative natural user interfaces that will power the spatially-enabled public health and emergency situation rooms of the future, where sensor data and citizen reports can be triaged and acted upon in real-time by distributed teams of professionals, this paper offers a comprehensive state-of-the-art review of the overlapping domains of the Sensor Web, citizen sensing and 'human-in-the-loop sensing' in the era of the Mobile and Social Web, and the roles these domains can play in environmental and public health surveillance and crisis/disaster informatics. We provide an in-depth review of the key issues and trends in these areas, the challenges faced when reasoning and making decisions with real-time crowdsourced data (such as issues of information overload, "noise", misinformation, bias and trust), the core technologies and Open Geospatial Consortium (OGC) standards involved (Sensor Web Enablement and Open GeoSMS), as well as a few outstanding project implementation examples from around the world.

Trajectory of Performance Status and Symptom Scores for Patients With Cancer During the Last Six Months of Life

Abstract: Purpose Ontario’s cancer system is unique because it has implemented two standardized assessment tools population-wide to improve care: the Edmonton Symptom Assessment System (ESAS) measures severity of nine symptoms (scale 0 to 10; 10 indicates the worst) and the Palliative Performance Scale (PPS) measures performance status (scale 0 to 100; 0 indicates death). This article describes the trajectory of ESAS and PPS scores 6 months before death.

Critical Perspectives on Consumers' Role as 'Producers': Broadening the Debate on Value Co-Creation in Marketing Processes

Abstract: This special issue continues the critical engagement with the popular discourses of Prahalad’s value co-creation paradigm and Vargo and Lusch’s service-dominant logic of marketing. The intensity of the debate among marketing scholars over these two marketing and management concepts demonstrates how much is at stake – conceptually and politically – when the roles of consumer and producer become blurred. Economic concepts of value, ownership, consumption, and production need to be redefined, and political ideas of the relationship between the social and the economic require addressing in the age of cognitive, or as we call it, collaborative capitalism. In addition to these broad theoretical challenges, the contributions in this issue zoom in on what arguably constitutes the central question for our specific field: What are the implications of a collaborative capitalism for understanding the place of marketing techniques in value creation? As with all good scholarship, the essays in this issue do not provide definitive answers but instead lead to a more elaborate set of questions. By doing so, they broaden the critical engagement with value co-creation in marketing.

Corporate social responsibility and developing countries moving the critical CSR research agenda in Africa forward

Abstract: The criticism that the mainstream corporate social responsibility (CSR) agenda was largely driven by the concerns and priorities of western countries and therefore tends to be insensitive to local priorities as well as inadvertently harm prospects for sustainable livelihood in developing countries set the tone for the emergence of a South-centred CSR agenda. The efforts to broaden the scope and content of mainstream CSR discourse and practice has meant three principal themes have come to dominate the emerging South-centred critical CSR agenda. The emergence of this critical perspective to CSR has not only contributed to the maturation of contemporary CSR agenda but has also generated rich insights with regard to the strengths and limitations of CSR practices within developing countries. However, the failure to critically engage with the role of government, adopt a bottom-up approach to CSR analysis and avoid a piecemeal research focus has meant the emerging Southern perspective to CSR is yet to achieve it...

Stereoscopic 3D-TV: Visual Comfort

Abstract: Among the key topics of discussion and research on three-dimensional television (3D-TV), visual comfort is certainly one of the most critical. This is because it is well known that some viewers experience visual discomfort when looking at stereoscopic displays. It is important to properly address the issue of visual comfort to avoid possible delays in the deployment of 3D-TV. Here we present a concise overview of the main topics relevant to comfort in viewing stereoscopic television and survey the key factors influencing visual comfort. Potential end users of 3D-TV, content creators, program providers, broadcasters, display manufacturers and researchers will find this overview useful.

MicroRNA miR-93 promotes tumor growth and angiogenesis by targeting integrin-β8.

Abstract: It has been reported that the miR-106b∼25 cluster, a paralog of the miR-17∼92 cluster, possesses oncogenic activities However, the precise role of each microRNA (miRNA) in the miR-106b∼25 cluster is not yet known In this study, we examined the function of miR-93, one of the microRNAs within the miR-106b∼25 cluster, in angiogenesis and tumor formation We found that miR-93 enhanced cell survival, promoted sphere formation and augmented tumor growth Most strikingly, when miR-93-overexpressing U87 cells were co-cultured with endothelial cells, they supported endothelial cell spreading, growth, migration and tube formation In vivo studies revealed that miR-93-expressing cells induced blood vessel formation, allowing blood vessels to extend to tumor tissues in high densities Angiogenesis promoted by miR-93 in return facilitated cell survival, resulting in enhanced tumor growth We further showed that integrin-β8 is a target of miR-93 Higher levels of integrin-β8 are associated with cell death in tumor mass and in human glioblastoma Silencing of integrin-β8 expression using small interfering RNA promoted cell proliferation, whereas ectopic expression of integrin-β8 decreased cell growth These findings showed that miR-93 promotes tumor growth and angiogenesis by suppressing, at least in part, integrin-β8 expression Our results suggest that inhibition of miR-93 function may be a feasible approach to suppress angiogenesis and tumor growth

Rules of Crowdsourcing: Models, Issues, and Systems of Control

Abstract: In this paper, we first provide a practical yet rigorous definition of crowdsourcing that incorporates “crowds,” outsourcing, and social web technologies. We then analyze 103 well-known crowdsourcing websites using content analysis methods and the hermeneutic reading principle. Based on our analysis, we develop a “taxonomic theory” of crowdsourcing by organizing the empirical variants in nine distinct forms of crowdsourcing models. We also discuss key issues and directions, concentrating on the notion of managerial control systems.