On the nature of the hard X-ray source IGR J2018+4043

We found a very likely counterpart to the recently discovered hard X-ray source IGR J2018+4043 in the multi-wavelength observations of the source field. The source, originally discovered in the 20-40 keV band, is now confidently detected also in the 40-80 keV band, with a flux of (1.4 +/- 0.4) x 10(-11) erg cm(-2) s(-1). A 5 ks Swift observation of the IGR J2018+4043 field revealed a hard point-like source with the observed 0.5-10 keV flux of 3.4(+0.7)(-0.8) x 10(-12) erg cm(-2) s(-1) (90% confidence level) at alpha = 20h18m38.55s, delta = +40d41m00.4s (with a 4.2" uncertainty). The combined Swift-INTEGRAL spectrum can be described by an absorbed power-law model with photon index gamma = 1.3 +/- 0.2 and N_H = 6.1(+3.2)(-2.2) x 10(22) cm(-2). In archival optical and infrared data we found a slightly extended and highly absorbed object at the Swift source position. There is also an extended VLA 1.4 GHz source peaked at a beam-width distance from the optical and X-ray positions. The observed morphology and multiwavelength spectra of IGR J2018+4043 are consistent with those expected for an obscured accreting object, i.e. an AGN or a Galactic X-ray binary. The identification suggests possible connection of IGR J2018+4043 to the bright gamma-ray source GEV J2020+4023 (3EG J2020+4017) detected by COS B and CGRO EGRET in the gamma-Cygni SNR field.Comment: 5 pages, 3 figures, uses emulateapj styl

Integrated modelling of cost-effective siting and operation of flow-control infrastructure for river ecosystem conservation

Wetland and floodplain ecosystems along many regulated rivers are highly stressed, primarily due to a lack of environmental flows of appropriate magnitude, frequency, duration, and timing to support ecological functions. In the absence of increased environmental flows, the ecological health of river ecosystems can be enhanced by the operation of existing and new flow-control infrastructure (weirs and regulators) to return more natural environmental flow regimes to specific areas. However, determining the optimal investment and operation strategies over time is a complex task due to several factors including the multiple environmental values attached to wetlands, spatial and temporal heterogeneity and dependencies, nonlinearity, and time-dependent decisions. This makes for a very large number of decision variables over a long planning horizon. The focus of this paper is the development of a nonlinear integer programming model that accommodates these complexities. The mathematical objective aims to return the natural flow regime of key components of river ecosystems in terms of flood timing, flood duration, and interflood period. We applied a 2-stage recursive heuristic using tabu search to solve the model and tested it on the entire South Australian River Murray floodplain. We conclude that modern meta-heuristics can be used to solve the very complex nonlinear problems with spatial and temporal dependencies typical of environmental flow allocation in regulated river ecosystems. The model has been used to inform the investment in, and operation of, flow-control infrastructure in the South Australian River Murray.<br /

The Sales Effect of Word of Mouth: A Model for Creative Goods and Estimates for Novels

Weekly sales of creative goods – like music records, movies or books – usually peak shortly after release and then decline quickly. In many cases, however, they follow a hump-shaped pattern where sales increase for some time. A popular explanation for this phenomenon is word of mouth among a population of heterogeneous buyers, but previous studies typically assume buyer homogeneity or neglect word of mouth altogether. In this paper, I study a model of new-product diffusion with heterogeneous buyers that allows for a quantification of the sales effect of word of mouth. The model includes Christmas sales as a special case. All parameters have an intuitive interpretation. Simulation results suggest that the parameters are estimable for data that are not too volatile and that cover a sufficiently large part of a title’s life cycle. I estimate the model for four exemplary novels using scanner data on weekly sales.Meistens erreichen die wöchentlichen Verkäufe von kreativen Produkten wie Musikalben, Kinofilmen oder Büchern kurz nach Veröffentlichung ihren Höhepunkt und nehmen dann schnell ab. In einigen Fällen jedoch zeigen sie einen buckelartigen Verlauf mit zunächst ansteigenden Verkäufen. Eine populäre Erklärung für dieses Phänomen beruht auf der Existenz von Mundpropaganda unter heterogenen Käufern, doch bisherige Studien gehen typischerweise von der Annahme homogener Käufer aus oder vernachlässigen Mundpropaganda gänzlich. Dieses Papier betrachtet ein Modell der Verbreitung neuer Produkte unter heterogenen Käufern, welches eine Quantifizierung der Verkaufswirkung von Mundpropaganda ermöglicht. Das Modell beinhaltet Weihnachtsverkäufe als Spezialfall. Alle Modellparameter haben eine intuitive Bedeutung. Ergebnisse einer Simulation zeigen, dass die Parameter empirisch geschätzt werden können, wenn die Daten einen hinreichend großen Teil des Verkaufszyklus eines Titels abdecken und nicht zu volatil sind. Das Modell wird auf Scannerdaten für vier exemplarische Romane angewendet

Effects of adaptation to sea water, 170% sea water and to fresh water on activities and subcellular distribution of branchial Na + −K + -ATPase, low- and high affinity Ca ++ -ATPase, and ouabain-insensitive ATPase in Gillichthys mirabilis

1. Branchial activities of Na + −K + -ATPase, ouabain-insensitive ATPase, (Mg ++ -ATPase) and Ca ++ -ATPase were measured in Gillichthys mirabilis after adaptation to salinities ranging from 170% SW to FW. Stabilities of these activities against freezing and deoxycholate solubilization and the temperature-dependence of activity rates were also investigated. Subcellular distribution and some kinetic properties of these activities, and of SDH were compared in branchial tissues of fish adapted to 170% SW and to FW.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47126/1/360_2004_Article_BF00782593.pd

Unconscious bias in the suppressive policing of Black and Latino men and boys: neuroscience, Borderlands theory, and the policymaking quest for just policing

his article applies neuroscience and Borderlands theory to reveal how unconscious bias currently stabilizes suppressive policing practices in America despite new efforts at reform. Illustrative cases are offered from Oakland and Santa Barbara, California, with a focus on civil gang injunctions (CGIs) and youth gang suppression. Theoretical analysis of these cases reveals how the unconscious biases of validity illusions and framing effects operate despite the best intentions of law enforcement personnel. Such unconscious or implicit biases create contradictions between the stated beliefs and actions of law enforcement. In turn, these unintended self-contradictions then work to the detriment of Latino and Black boys. The analysis here also extends to how unconscious biases and unintended self-contradictions can influence municipal policymaking in favor of suppressive police tactics such as CGIs, thereby displacing evidence-based policies that are proven to be far more effective. The article concludes with brief discussion of some of the means by which the unconscious biases – effects to which everyone is involuntarily prone – can be disrupted

Localization by acoustic emission in transversely isotropic slate

A method for localization by acoustic emission in transversely isotropic media is developed and validated. Velocities are experimentally measured and then used to calculate a database of theoretical arrival times for a large number of positions. During an actual test, positions are assigned by comparing measured arrival times with the database's arrival times. The method is applied during load tests on slate samples and compared with visual observations of fractures. The localization method allowed for a good identification of the regions of fracturing at different stages during the test. © 2011 Bjorn Debecker and André Vervoort.Published in : Advances in Acoustics and Vibrationstatus: publishe

Genesis of active and inactive species during the preparation of MoO3/SiO2-Al2O3 metathesis catalysts via wet impregnation

The wet impregnation of ammonium heptamolybdate onto silica-alumina is used to prepare MoO3/SiO2-Al2O3 heterogeneous metathesis catalysts. The preparation is inspected in details in conjunction with physico-chemical characterization tools with the aim to identify the parameters that dictate the genesis of active and inactive metathesis species. The effects of the MoO3 loading and of the calcination temperature are systematically explored. The samples are characterized by N2-physisorption, ICP-AES, XRD, Raman, 27Al MAS-NMR and XPS and evaluated in the metathesis of propene to butene and ethene. Particular attention is brought to the interaction of the mesoporous silica-alumina support with the active component, to the decomposition of the precursor salt and to the location of the molybdenum oxide phase with respect to the pores of the support. It is shown that the temperature of calcination influences markedly the performances of the catalyst. High temperature treatments are necessary to decompose efficiently the Mo salt precursor. In the metathesis of propylene, the performances are levelling off when the MoO 3 loading is increased above ∼8 wt.%. This effect is correlated to the build up of MoO 3 crystals and of Al2(MoO4)3 at relatively high loading. © 2010 Elsevier B.V. All rights reserved

Experimental study of serpentinization and abiotic CH4_4 production in martian conditions.

The presence of methane on Mars remains highly debated in particular with contrasted detection results from Curiosity rover [1] and TGO [2]. In addition, the possible methane cycle is also poorly known: source(s) and removal process(es) remain currently undefined; and it is not known yet if this methane emissions might be related to a biological activity. Because of orbital detection of serpentine on Mars [3], and of the mafic-ultramafic nature of Mars ancient crust, a putative abiotic candidate source is serpentinization associated with Sabatier reaction. The aim of this work is to experimentally study the production capacity of H2 and mainly CH4 by those abiotic processes in martian conditions to determine the viability of this origin