Activated Magnetospheres of Magnetars

Like the solar corona, the external magnetic field of magnetars is twisted by surface motions of the star. The twist energy is dissipated over time. We discuss the theory of this activity and its observational status. (1) Theory predicts that the magnetosphere tends to untwist in a peculiar way: a bundle of electric currents (the "j-bundle") is formed with a sharp boundary, which shrinks toward the magnetic dipole axis. Recent observations of shrinking hot spots on magnetars are consistent with this behavior. (2) Continual discharge fills the j-bundle with electron-positron plasma, maintaining a nonthermal corona around the neutron star. The corona outside a few stellar radii strongly interacts with the stellar radiation and forms a "radiatively locked" outflow with a high e+- multiplicity. The locked plasma annihilates near the apexes of the closed magnetic field lines. (3) New radiative-transfer simulations suggest a simple mechanism that shapes the observed X-ray spectrum from 0.1 keV to 1 MeV: part of the thermal X-rays emitted by the neutron star are reflected from the outer corona and then upscattered by the inner relativistic outflow in the j-bundle, producing a beam of hard X-rays.Comment: 23 pages, 7 figures; review chapter in the proceedings of ICREA Workshop on the High-Energy Emission from Pulsars and Their Systems, Sant Cugat, Spain, April 201

X-ray emission from isolated neutron stars

X-ray emission is a common feature of all varieties of isolated neutron stars (INS) and, thanks to the advent of sensitive instruments with good spectroscopic, timing, and imaging capabilities, X-ray observations have become an essential tool in the study of these objects. Non-thermal X-rays from young, energetic radio pulsars have been detected since the beginning of X-ray astronomy, and the long-sought thermal emission from cooling neutron star's surfaces can now be studied in detail in many pulsars spanning different ages, magnetic fields, and, possibly, surface compositions. In addition, other different manifestations of INS have been discovered with X-ray observations. These new classes of high-energy sources, comprising the nearby X-ray Dim Isolated Neutron Stars, the Central Compact Objects in supernova remnants, the Anomalous X-ray Pulsars, and the Soft Gamma-ray Repeaters, now add up to several tens of confirmed members, plus many candidates, and allow us to study a variety of phenomena unobservable in "standard'' radio pulsars.Comment: Chapter to be published in the book of proceedings of the 1st Sant Cugat Forum on Astrophysics, "ICREA Workshop on the high-energy emission from pulsars and their systems", held in April, 201

Search for gamma-ray emission from magnetars with the Fermi Large Area Telescope

We report on the search for 0.1-10 GeV emission from magnetars in 17 months of Fermi Large Area Telescope (LAT) observations. No significant evidence for gamma-ray emission from any of the currently-known magnetars is found. The most stringent upper limits to date on their persistent emission in the Fermi-LAT energy range are estimated between ~10^{-12}-10^{-10} erg/s/cm2, depending on the source. We also searched for gamma-ray pulsations and possible outbursts, also with no significant detection. The upper limits derived support the presence of a cut-off at an energy below a few MeV in the persistent emission of magnetars. They also show the likely need for a revision of current models of outer gap emission from strongly magnetized pulsars, which, in some realizations, predict detectable GeV emission from magnetars at flux levels exceeding the upper limits identified here using the Fermi-LAT observations.Comment: ApJ Letters in press; Corresponding authors: Caliandro G. A., Hadasch D., Rea N., Burnett

The role of leadership in salespeople’s price negotiation behavior

Salespeople assume a key role in defending firms’ price levels in price negotiations with customers. The degree to which salespeople defend prices should critically depend upon their leaders’ influence. However, the influence of leadership on salespeople’s price defense behavior is barely understood, conceptually or empirically. Therefore, building on social learning theory, the authors propose that salespeople might adopt their leaders’ price defense behavior given a transformational leadership style. Furthermore, drawing on the contingency leadership perspective, the authors argue that this adoption fundamentally depends on three variables deduced from the motivation–ability–opportunity (MAO) framework, that is, salespeople’s learning motivation, negotiation efficacy, and perceived customer lenience. Results of a multi-level model using data from 92 salespeople and 264 salesperson–customer interactions confirm these predictions. The first to explore contingencies of salespeople’s adoption of their transformational leaders’ price negotiation behaviors, this study extends marketing theory and provides actionable guidance to practitioners

Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes

BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events

A report on decisions on air quality standards for the year 1993

On sale at: Distribution centre VROM distribution number 3655, P.O. Box 351, 2700 AJ Zoetermeer.De besluiten luchtkwaliteit bevatten luchtkwaliteitseisen voor de stoffen zwaveldioxide, zwevende deeltjes (zwarte rook), stikstofdioxide, koolstofmonoxide, lood en benzeen. Jaarlijks rapporteren de provincies over overschrijding van de in de besluiten genoemde kwaliteitseisen en over maatregelen om een einde te maken aan deze overschrijdingen. De provincies verwerken in hun rapportages de rapportages van de gemeenten. Op basis van de ontvangen rapportages over het jaar 1993 hebben het Rijksinstituut voor Volksgezondheid en Milieuhygiene en het Directoraat-generaal Milieubeheer deze landelijke rapportage opgesteld. Conform afspraken gemaakt in DUIV-kader is deze rapportage de eerste landelijke rapportage die eens in de vier jaar zal verschijnen. Het belangrijkste doel van de rapportage is inzicht te geven in de kwaliteit van de buitenlucht voor de betreffende stoffen en in de maatregelen die genomen zijn of zullen worden om die kwaliteit te verbeteren.The executive orders on air quality consist of air quality standards for the substances sulphur dioxide, suspended particles (black smoke), nitrogen dioxide, carbon monoxide, lead and benzene. The provincial authorities report annually on exceedances of the air quality standards laid down in the regulations, and on measures to prevent such exceedances. The provinces compose their reports using the information submitted by local authorities. The National Institute of Public Health and Environmental Protection (RIVM) and the Directorate General for the Environment of the Ministry of VROM have compiled this national report on the basis of the reports received for 1993. The most important aim of the report is to provide information on the quality of the ambient air with respect to the substances concerned, and on the measures which have been or will be implemented in order to improve air quality.DGM/L

A report on decisions on air quality standards for the year 1996

Available from: Distribution Centre VROM, distribution code 17514/187, P.O. 351, 2700 AJ Zoetermeer, telephone: 31-79-3449449Deze rapportage is gebaseerd op rapportages van provincies en gemeenten over overschrijding van de (uitzonderings) grenswaarden voor zwaveldioxide, fijn stof (zwarte rook), stikstofdioxide, koolstofmonoxide , lood en benzeen. Rond inrichtingen zijn geen overschrijdingen van grenswaarden gerapporteerd. Op 116 wegvakken werden overschrijdingen van (uitzonderings)grenswaarden gerapporteerd: 52 keer benzeen, 62 keer stikstofdioxide en 2 keer koolstofmonoxide.This report is based on reports from provinces and municipalities on exceedances of the air quality standards for the compounds sulphur dioxide, suspended particles (black smoke), nitrogen dioxide, carbon monoxide, lead and benzene. No exceedances of air quality standards were reported for industrial areas. For 116 roadblocks exceedances were reported: 52 times benzene, 62 times nitrogen dioxide and 2 times carbon monoxideDGM/L