1,615 research outputs found

    Managing project interdependencies: exploring new approaches

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    The interdependencies between projects create complexities for the management of project portfolios within organisations. In times of uncertainty this challenge is even greater due to the difficulties in predicting the flow-on effects from changes to projects in the portfolio. Hence, in times of disruptive change a good understanding of project interdependencies is particularly important. This paper outlines two related studies that aim to improve the understanding and management of interdependencies within project portfolios. The paper first defines project portfolio management (PPM) and highlights its growing importance for optimising organisational outcomes, especially in dynamic environments. Project portfolio complexity and interdependencies between projects in a portfolio are then overviewed, highlighting the challenges that these interdependencies create for effective PPM, and introducing some of the methods used for understanding and managing these interdependencies including the dependency matrix and the related design structure matrix. Network analysis and mapping tools are then introduced and suggested as a novel method for improving understanding and managing project interdependencies. Finally, an example of the use of this type of method is presented and the current research projects are overviewed

    The first multi-wavelength campaign of AXP 4U 0142+61 from radio to hard X-rays

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    For the first time a quasi-simultaneous multi-wavelength campaign has been performed on an Anomalous X-ray Pulsar from the radio to the hard X-ray band. 4U 0142+61 was an INTEGRAL target for 1 Ms in July 2005. During these observations it was also observed in the X-ray band with Swift and RXTE, in the optical and NIR with Gemini North and in the radio with the WSRT. In this paper we present the source-energy distribution. The spectral results obtained in the individual wave bands do not connect smoothly; apparently components of different origin contribute to the total spectrum. Remarkable is that the INTEGRAL hard X-ray spectrum (power-law index 0.79 +/- 0.10) is now measured up to an energy of ~230 keV with no indication of a spectral break. Extrapolation of the INTEGRAL power-law spectrum to lower energies passes orders of magnitude underneath the NIR and optical fluxes, as well as the low ~30 microJy (2 sigma) upper limit in the radio band.Comment: 6 pages, 1 figure. To be published in the proceedings of the conference "Isolated Neutron Stars: from the Interior to the Surface" (April 24-28, 2006, London, UK), eds. S. Zane, R. Turolla and D. Pag

    The magnetar emission in the IR band: the role of magnetospheric currents

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    There is a general consensus about the fact that the magnetar scenario provides a convincing explanation for several of the observed properties of the Anomalous X-ray Pulsars and the Soft Gamma Repeaters. However, the origin of the emission observed at low energies is still an open issue. We present a quantitative model for the emission in the optical/infrared band produced by curvature radiation from magnetospheric charges, and compare results with current magnetars observations.Comment: 6 Pages, 2 Figures. Astrophysics and Space Science, in press. Proceedings of the ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, April 12-16 201

    Recent Progress on Anomalous X-ray Pulsars

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    I review recent observational progress on Anomalous X-ray Pulsars, with an emphasis on timing, variability, and spectra. Highlighted results include the recent timing and flux stabilization of the notoriously unstable AXP 1E 1048.1-5937, the remarkable glitches seen in two AXPs, the newly recognized variety of AXP variability types, including outbursts, bursts, flares, and pulse profile changes, as well as recent discoveries regarding AXP spectra, including their surprising hard X-ray and far-infrared emission, as well as the pulsed radio emission seen in one source. Much has been learned about these enigmatic objects over the past few years, with the pace of discoveries remaining steady. However additional work on both observational and theoretical fronts is needed before we have a comprehensive understanding of AXPs and their place in the zoo of manifestations of young neutron stars.Comment: 10 pages, 6 figures; to appear in proceedings of the conference "Isolated Neutron Stars: From the Interior to the Surface" eds. S. Zane, R. Turolla, D. Page; Astrophysics & Space Science in pres

    Influence of host plant, geography and pheromone strain on genomic differentiation in sympatric populations of Ostrinia nubilalis

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    Patterns of mating for the European corn borer (Ostrinia nubilalis) moth depend in part on variation in sex‐pheromone blend. The ratio of (E)‐11‐ and (Z)‐11‐tetradecenyl acetate (E11‐ and Z11‐14:OAc) in the pheromone blend that females produce and males respond to differs between strains of O. nubilalis. Populations also vary in female oviposition preference for and larval performance on maize (C4) and non‐maize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure of O. nubilalis remains unknown. Host‐plant use (13C/14C ratios) and genetic differentiation were estimated among sympatric E and Z pheromone strain O. nubilalis males collected in sex‐pheromone baited traps at 12 locations in Pennsylvania and New York between 2007 and 2010. Among genotypes at 65 single nucleotide polymorphism marker loci, variance at a position in the pheromone gland fatty acyl‐reductase (pgfar) gene at the locus responsible for determining female pheromone ratio (Pher) explained 64% of the total genetic differentiation between males attracted to different pheromones (male response, Resp), providing evidence of sexual inter‐selection at these unlinked loci. Principal coordinate, Bayesian clustering, and distance‐based redundancy analysis (dbRDA) demonstrate that host plant history or geography does not significantly contribute to population variation or differentiation among males. In contrast, these analyses indicate that pheromone response and pgfar‐defined strain contribute significantly to population genetic differentiation. This study suggests that behavioral divergence likely plays a larger role in driving genetic variation compared to host plant‐defined ecological adaptation

    A third red supergiant rich cluster in the Scutum-Crux arm

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    Aims. We aim to characterise the properties of a third massive, red supergiant dominated galactic cluster. Methods. To accomplish this we utilised a combination of near/mid-IR photometry and spectroscopy to identify and classify the properties of cluster members, and statistical arguments to determine the mass of the cluster. Results. We found a total of 16 strong candidates for cluster membership, for which formal classification of a subset yields spectral types from K3-M4 Ia and luminosities between log(L/L-circle dot) similar to 4.5-4.8 for an adopted distance of 6 +/- 1 kpc. For an age in the range of 16-20 Myr, the implied mass is 2-4 x 10(4) M-circle dot, making it one of the most massive young clusters in the Galaxy. This discovery supports the hypothesis that a significant burst of star formation occurred at the base of Scutum-Crux arm between 10-20 Myr ago, yielding a stellar complex comprising at least similar to 10(5) M-circle dot of stars (noting that since the cluster identification criteria rely on the presence of RSGs, we suspect that the true stellar yield will be significantly higher). We highlight the apparent absence of X-ray binaries within the star formation complex and finally, given the physical association of at least two pulsars with this region, discuss the implications of this finding for stellar evolution and the production and properties of neutron stars

    Inside athletes' minds: Preliminary results from a pilot study on mental representation of doping and potential implications for anti-doping

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    <p>Abstract</p> <p>Background</p> <p>Despite the growing body of literature and putative links between the use of ergogenic nutritional supplements, doping and illicit drugs, it remains unclear whether, in athletes' minds, doping aligns with illicit behaviour or with functional use of chemical or natural preparations. To date, no attempt has been made to quantitatively explore athletes' mental representation of doping in relation to illegality and functionality.</p> <p>Methods</p> <p>A convenience sample of student athletes from a large South-Eastern Australian university responded to an on-line survey. Competitive athletes (n = 46) were grouped based on self-reported use as follows: i) none used (30%), ii) supplement only (22%), iii) illicit only (26%) and iv) both supplements and illicit drug use (22%). Whereas no athlete reported doping, data provided on projected supplement-, doping- and drug use by the four user groups allowed evaluation of doping-related cognition in the context of self-reported supplement- and illicit drug taking behaviour; and comparison between these substances.</p> <p>Results</p> <p>A significantly higher prevalence estimation was found for illicit drug use and a trend towards a biased social projection emerged for supplement use. Doping estimates by user groups showed mixed results, suggesting that doping had more in common with the ergogenic nutritional supplement domain than the illicit drug domain.</p> <p>Conclusions</p> <p>Assessing the behavioural domain to which doping belongs to in athletes' mind would greatly advance doping behaviour research toward prevention and intervention. Further investigation refining the peculiarity of the mental representation of doping with a larger study sample, controlling for knowledge of doping and other factors, is warranted.</p

    The Broad Challenge of Public Engagement in Science: Commentary on: “Constitutional Moments in Governing Science and Technology”

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    Timely public engagement in science presents a broad challenge. It includes more than research into the ethical, legal and social dimensions of science and state-initiated citizen’s participation. Introducing a public perspective on science while safeguarding its public value involves a diverse set of actors: natural scientists and engineers, technology assessment institutes, policy makers, social scientists, citizens, interest organisations, artists, and last, but not least, politicians

    A Longitudinal Relationship Between Depressive Symptoms and Development of Metabolic Syndrome: The Coronary Artery Risk Development in Young Adults Study

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    Despite variability in the burden of elevated depressive symptoms by sex and race and differences in the incidence of metabolic syndrome, few prior studies describe the longitudinal association of depressive symptoms with metabolic syndrome in a diverse cohort. We tested whether baseline and time-varying depressive symptoms were associated with metabolic syndrome incidence in black and white men and women from the Coronary Artery Risk Development in Young Adults (CARDIA) study
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