Accreting Neutron Stars in Low-Mass X-Ray Binary Systems

Using the Rossi X-ray Timing Explorer (RossiXTE), astronomers have discovered that disk-accreting neutron stars with weak magnetic fields produce three distinct types of high-frequency X-ray oscillations. These oscillations are powered by release of the binding energy of matter falling into the strong gravitational field of the star or by the sudden nuclear burning of matter that has accumulated in the outermost layers of the star. The frequencies of the oscillations reflect the orbital frequencies of gas deep in the gravitational field of the star and/or the spin frequency of the star. These oscillations can therefore be used to explore fundamental physics, such as strong-field gravity and the properties of matter under extreme conditions, and important astrophysical questions, such as the formation and evolution of millisecond pulsars. Observations using RossiXTE have shown that some two dozen neutron stars in low-mass X-ray binary systems have the spin rates and magnetic fields required to become millisecond radio-emitting pulsars when accretion ceases, but that few have spin rates above about 600 Hz. The properties of these stars show that the paucity of spin rates greater than 600 Hz is due in part to the magnetic braking component of the accretion torque and to the limited amount of angular momentum that can be accreted in such systems. Further study will show whether braking by gravitational radiation is also a factor. Analysis of the kilohertz oscillations has provided the first evidence for the existence of the innermost stable circular orbit around dense relativistic stars that is predicted by strong-field general relativity. It has also greatly narrowed the possible descriptions of ultradense matter.Comment: 22 pages, 7 figures, updated list of sources and references, to appear in "Short-period Binary Stars: Observation, Analyses, and Results", eds. E.F. Milone, D.A. Leahy, and D. Hobill (Dordrecht: Springer, http://www.springerlink.com

Millisecond Oscillations in X-Ray Binaries

The first millisecond X-ray variability phenomena from accreting compact objects have recently been discovered with the Rossi X-ray Timing Explorer. Three new phenomena are observed from low-mass X-ray binaries containing low-magnetic-field neutron stars: millisecond pulsations, burst oscillations and kiloHertz quasi-periodic oscillations. Models for these new phenomena involve the neutron star spin, and orbital motion closely around the neutron star and rely explicitly on our understanding of strong gravity and dense matter. I review the observations of these new neutron-star phenomena and possibly related ones in black-hole candidates, and describe the attempts to use them to perform measurements of fundamental physical interest in these systems.Comment: 40 pages, 17 figures, 4 tables - submitted to the Annual Review of Astronomy and Astrophysics; to appear September 200

Exploring earned value management in the Spanish construction industry as a pathway to competitive advantage

[EN] As a well established discipline and profession, project management has its distinctive tools and techniques. One of them that has been considered the embodiment of the core principles of project management is the Earned Value Management (EVM). In managing construction projects, the EVM has been considered as a suitable tool and hence, has been implemented in various construction industry but absent in some others. Taking into account the dynamic environment where construction companies have to operate, particularly in turbulence environments as the direct result of recent global economic downturn, this paper explores the potential implementation of EVM in one of the construction industry, the Spanish construction industry. The outcomes confirm the needs for and feasibility of implementing EVM as a structured approach in the industry to reposition the Spanish construction industry with the long term view to increase its project management maturity level as a pathway to gaining competitive advantage.Universitat Politecnica de Valencia [grant number 19701344]Sutrisna, M.; Pellicer, E.; Torres-Machí, C.; Picornell, M. (2018). Exploring earned value management in the Spanish construction industry as a pathway to competitive advantage. International Journal of Construction Management. 20(1):1-12. https://doi.org/10.1080/15623599.2018.1459155S112201Anbari, F. T. (2004). Earned value project management method and extensions. IEEE Engineering Management Review, 32(3), 97-97. doi:10.1109/emr.2004.25113Aram, J. D., & Walochik, K. (1996). Improvisation and the Spanish Manager. International Studies of Management & Organization, 26(4), 73-89. doi:10.1080/00208825.1996.11656695Brandon, D. M. (1998). Implementing Earned Value Easily and Effectively. Project Management Journal, 29(2), 11-18. doi:10.1177/875697289802900204Brown, A., & Adams, J. (2000). Measuring the effect of project management on construction outputs: a new approach. International Journal of Project Management, 18(5), 327-335. doi:10.1016/s0263-7863(99)00026-5Bryde, D. J. (2003). Modelling project management performance. International Journal of Quality & Reliability Management, 20(2), 229-254. doi:10.1108/02656710310456635Chen, H. L., Chen, W. T., & Lin, Y. L. (2016). Earned value project management: Improving the predictive power of planned value. International Journal of Project Management, 34(1), 22-29. doi:10.1016/j.ijproman.2015.09.008De la Cruz, M. P., del Caño, A., & de la Cruz, E. (2006). Downside Risks in Construction Projects Developed by the Civil Service: The Case of Spain. Journal of Construction Engineering and Management, 132(8), 844-852. doi:10.1061/(asce)0733-9364(2006)132:8(844)Din, S., Abd-Hamid, Z., & Bryde, D. J. (2011). ISO 9000 certification and construction project performance: The Malaysian experience. International Journal of Project Management, 29(8), 1044-1056. doi:10.1016/j.ijproman.2010.11.001Eldin, N. N. (1989). Measurement of Work Progress: Quantitative Technique. Journal of Construction Engineering and Management, 115(3), 462-474. doi:10.1061/(asce)0733-9364(1989)115:3(462)Gidado, K. I. (1996). Project complexity: The focal point of construction production planning. Construction Management and Economics, 14(3), 213-225. doi:10.1080/014461996373476Hastak, M., Halpin, D. W., & Vanegas, J. (1996). COMPASS—New Paradigm for Project Cost Control Strategy and Planning. Journal of Construction Engineering and Management, 122(3), 254-264. doi:10.1061/(asce)0733-9364(1996)122:3(254)D. Holt, G., & S. Goulding, J. (2014). Conceptualisation of ambiguous-mixed-methods within building and construction research. Journal of Engineering, Design and Technology, 12(2), 244-262. doi:10.1108/jedt-02-2013-0020Ibbs, C. W., & Kwak, Y. H. (2000). Assessing Project Management Maturity. Project Management Journal, 31(1), 32-43. doi:10.1177/875697280003100106Jugdev, K., & Thomas, J. (2002). 2002 Student Paper Award Winner: Project Management Maturity Models: The Silver Bullets of Competitive Advantage? Project Management Journal, 33(4), 4-14. doi:10.1177/875697280203300402Kim, E., Wells, W. G., & Duffey, M. R. (2003). A model for effective implementation of Earned Value Management methodology. International Journal of Project Management, 21(5), 375-382. doi:10.1016/s0263-7863(02)00049-2Kim, T., Kim, Y.-W., & Cho, H. (2016). Customer Earned Value: Performance Indicator from Flow and Value Generation View. Journal of Management in Engineering, 32(1), 04015017. doi:10.1061/(asce)me.1943-5479.0000377Laufer, A., & Tucker, R. L. (1987). Is construction project planning really doing its job? A critical examination of focus, role and process. Construction Management and Economics, 5(3), 243-266. doi:10.1080/01446198700000023Liberatore, M. J., Pollack-Johnson, B., & Smith, C. A. (2001). Project Management in Construction: Software Use and Research Directions. Journal of Construction Engineering and Management, 127(2), 101-107. doi:10.1061/(asce)0733-9364(2001)127:2(101)Mir, F. A., & Pinnington, A. H. (2014). Exploring the value of project management: Linking Project Management Performance and Project Success. International Journal of Project Management, 32(2), 202-217. doi:10.1016/j.ijproman.2013.05.012Navon, R., & Haskaya, I. (2006). Is detailed progress monitoring possible without designated manual data collection? Construction Management and Economics, 24(12), 1225-1229. doi:10.1080/01446190600999097Onwuegbuzie, A. J., & Leech, N. L. (2005). Taking the «Q» Out of Research: Teaching Research Methodology Courses Without the Divide Between Quantitative and Qualitative Paradigms. Quality & Quantity, 39(3), 267-295. doi:10.1007/s11135-004-1670-0Oviedo-Haito, R. J., Jiménez, J., Cardoso, F. F., & Pellicer, E. (2014). Survival Factors for Subcontractors in Economic Downturns. Journal of Construction Engineering and Management, 140(3), 04013056. doi:10.1061/(asce)co.1943-7862.0000811Pellicer, E., Sanz, M. A., Esmaeili, B., & Molenaar, K. R. (2016). Exploration of Team Integration in Spanish Multifamily Residential Building Construction. Journal of Management in Engineering, 32(5), 05016012. doi:10.1061/(asce)me.1943-5479.0000438Potts, K., & Ankrah, N. (2008). Construction Cost Management. doi:10.4324/9780203933015Vanhoucke, M. (2012). Project Management with Dynamic Scheduling. doi:10.1007/978-3-642-25175-7Yazici, H. J. (2009). The Role of Project Management Maturity and Organizational Culture in Perceived Performance. Project Management Journal, 40(3), 14-33. doi:10.1002/pmj.20121Yu, A. G., Flett, P. D., & Bowers, J. A. (2005). Developing a value-centred proposal for assessing project success. International Journal of Project Management, 23(6), 428-436. doi:10.1016/j.ijproman.2005.01.00

Anticonvulsant effects of aerial parts of Passiflora incarnata extract in mice: involvement of benzodiazepine and opioid receptors

<p>Abstract</p> <p>Background</p> <p>Passion flower (<it>Passiflora incarnata</it>) is used in traditional medicine of Europe and South America to treat anxiety, insomnia and seizure. Recently, it has shown antianxiety and sedative effects in human.</p> <p>Methods</p> <p>In this study, anticonvulsant effects of hydro- alcoholic extract of Passiflora, Pasipay, were examined by using pentylentetrazole model (PTZ) on mice. Pasipay, diazepam, and normal saline were injected intraperitoneally at the doses 0.4–0.05 mg/kg, 0.5–1 mg/kg and 10 ml/kg respectively 30 minutes before PTZ (90 mg/kg, i.p). The time taken before the onset of clonic convulsions, the duration of colonic convulsions, and the percentage of seizure and mortality protection were recorded. For investigating the mechanism of Pasipay, flumazenil (2 mg/kg, i.p) and naloxone (5 mg/kg, i.p) were also injected 5 minutes before Pasipay.</p> <p>Results</p> <p>An ED₅₀value of Pasipay in the PTZ model was 0.23 mg/kg (%95 CL: 0.156, 0.342). Pasipay at the dose of 0.4 mg/kg prolonged the onset time of seizure and decreased the duration of seizures compared to saline group (p < 0.001). At the dose of 0.4 mg/kg, seizure and mortality protection percent were 100%. Flumazenil and naloxone could suppress anticonvulsant effects of Pasipay.</p> <p>Conclusion</p> <p>It seems that Pasipay could be useful for treatment absence seizure and these effects may be related to effect of it on GABAergic and opioid systems. More studies are needed in order to investigate its exact mechanism.</p

A Project Portfolio Management Approach to Tacklingthe Exploration/Exploitation Trade-off

Organizational ambidexterity (OA) is an essen-tial capability for surviving in dynamic business environ-ments that advocates the simultaneous engagement inexploration and exploitation. Over the last decades,knowledge on OA has substantially matured, coveringinsights into antecedents, outcomes, and moderators of OA.However, there is little prescriptive knowledge that offersguidance on how to put OA into practice and to tackle thetrade-off between exploration and exploitation. To addressthis gap, the authors adopt the design science researchparadigm and propose an economic decision model asartifact. The decision model assists organizations inselecting and scheduling exploration and exploitation pro-jects to become ambidextrous in an economically reason-able manner. As for justificatory knowledge, the decisionmodel draws from prescriptive knowledge on projectportfolio management and value-based management, andfrom descriptive knowledge related to OA to structure thefield of action. To evaluate the decision model, its designspecification is discussed against theory-backed designobjectives and with industry experts. The paper alsoinstantiates the decision model as a software prototype andapplies the prototype to a case based on real-world data

Do AAO-HNSF CORE Grants Predict Future NIH Funding Success?

Objective. To determine (1) whether academic otolaryngologists who have received an American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) Centralized Otolaryngology Research Efforts (CORE) grant are more likely to procure future National Institutes of Health (NIH) funding; (2) whether CORE grants or NIH Career Development (K) awards have a stronger association with scholarly impact. Study Design and Setting. Historical cohort. Methods. Scholarly impact, as measured by the h-index, publication experience, and prior grant history, were determined for CORE-funded and non-CORE-funded academic otolaryngologists. All individuals were assessed for NIH funding history. Results. Of 192 academic otolaryngologists with a CORE funding history, 39.6% had active or prior NIH awards versus 15.1% of 1002 non-CORE-funded faculty (P \u3c .0001). Higher proportions of CORE-funded otolaryngologists have received K-series and R-series grants from the NIH (P-values \u3c .05). K-grant recipients had higher h-indices than CORE recipients (12.6 vs 7.1, P \u3c .01). Upon controlling for rank and experience, this difference remained significant among junior faculty. Conclusions. A higher proportion of academic otolaryngologists with prior AAO-HNSF CORE funding have received NIH funding relative to their non-CORE-funded peers, suggesting that the CORE program may be successful in its stated goals of preparing individuals for the NIH peer review process, although further prospective study is needed to evaluate a cause and effect relationship. Individuals with current or prior NIH K-grants had greater research productivity than those with CORE funding history. Both cohorts had higher scholarly impact values than previously published figures among academic otolaryngologists, highlighting that both CORE grants and NIH K-grants awards are effective career development resources

Bibliometric analyses of physical and occupational therapy faculty across Canada indicate productivity and impact of rehabilitation research

© 2015, University of Toronto Press Inc. All rights reserved. Purpose: This study examines physical and occupational therapy faculty across Canada, using bibliometrics and federal funding as indicators of academic impact, and considers the validity of various bibliometric indices. Methods: Faculty members were identified and their rank, professional designation, and department obtained from faculty Web sites. Bibliometric indicators were determined using Publish or Perish software. An independent author (not a faculty member) inspected the data to remove any incorrectly attributed publications. The h-index, citation years, g-index, and total number of citations for each faculty member were retrieved. The Canadian Institutes of Health Research (CIHR) funding database was used to determine the amount of research funding provided to each faculty member as a principal investigator (PI) and his or her total CIHR funding received. Mean faculty indicators by university, rank, gender, and profession were determined. Analysis of variance (ANOVA) was used to detect differences by rank and gender, and measures of association (Pearson correlation coefficients and multiple regression) were used to identify factors that affected h-index and PI funding received. Results: A total of 347 physical and occupational therapy faculty were identified. The median h-index was 5 (inter-quartile range [IQR] 2–8) for assistant professors, 11 (IQR 7– 15) for associate professors, and 18 (IQR 12–26) for full professors. ANOVA indicated no significant differences between male and female faculty in terms of h-index or funding received. Regression analysis indicated that 58% of h-index variance could be explained by gender (p = 0.039), appointment within a department that provides a (rehabilitation science) PhD programme (p \u3c 0.001), rank (p \u3c 0.001), CIHR PI funding (p = 0.001), or total CIHR funding (p \u3c 0.001). Significant predictors of the amount of CIHR funding received as a PI included h-index (p \u3c 0.001) and total number of citations (p = 0.023), which together explained 27% of the variation in funding received. Conclusion: The h-index, although not without flaws, provides a useful metric that indicates that physical and occupational faculty in Canada are productive scientists having a measurable impact and that this impact increases with rank and greater funding