The Firm Foundation of Organizational Flexibility: The 360 Contract in the Digitalizing Music Industry

The devaluation of the recorded music commodity under digitalization has destabilized the recording industry. One primary record industry response is the new “360 deal” form of the recording contract. By securing rights to individual acts’ live performance, music publishing and licensing, and merchandizing activities, this new deal expands record companies’ access to more profitable fields of music industry activity (if in piecemeal fashion). We examine the context, evolution, and varieties of the 360 deal, and argue that it re-secures record industry profitability and further stratifies the population of recording artists by shifting risk onto performers

Verification of a New NOAA/NSIDC Passive Microwave Sea-Ice Concentration Climate Record

A new satellite-based passive microwave sea-ice concentration product developed for the National Oceanic and Atmospheric Administration (NOAA)Climate Data Record (CDR) programme is evaluated via comparison with other passive microwave-derived estimates. The new product leverages two well-established concentration algorithms, known as the NASA Team and Bootstrap, both developed at and produced by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC). The sea ice estimates compare well with similar GSFC products while also fulfilling all NOAA CDR initial operation capability (IOC) requirements, including (1) self describing file format, (2) ISO 19115-2 compliant collection-level metadata,(3) Climate and Forecast (CF) compliant file-level metadata, (4) grid-cell level metadata (data quality fields), (5) fully automated and reproducible processing and (6) open online access to full documentation with version control, including source code and an algorithm theoretical basic document. The primary limitations of the GSFC products are lack of metadata and use of untracked manual corrections to the output fields. Smaller differences occur from minor variations in processing methods by the National Snow and Ice Data Center (for the CDR fields) and NASA (for the GSFC fields). The CDR concentrations do have some differences from the constituent GSFC concentrations, but trends and variability are not substantially different

Investigating local policy drivers for alcohol harm prevention: a comparative case study of two local authorities in England

AbstractBackground The recent transfer of public health teams to local authorities in England offers opportunities for new policy approaches to tackling alcohol harm. The new responsible authority status of directors of public health, for example with regard to licensing applications, raises the prospect of reducing excessive alcohol consumption through local availability measures. Local authorities are also responsible for the commissioning of community-based treatment services. We used a case study approach to identify the major drivers and characteristics of local alcohol policies and services in two contrasting local authorities. Methods The many sources used were semi-structured interviews with key informants, including two in public health, two in licensing and trading standards, one in the police, and one information specialist; documentary analysis, including two alcohol strategies; two statements of licensing policy; and field observation (attending a licensing committee hearing). Focusing on alcohol harm prevention programmes and their underlying objectives, we used storyboards and constant comparative methods to describe and explain differences in the alcohol policy landscape between the two local authorities. Ethics approval was obtained from the University of Sheffield Ethics Committee. Findings Substantial differences in the stated priorities of alcohol harm prevention strategies were shown in the contrasting policy responses of the two local authorities. Concern about how best to reduce high rates of alcohol-related hospital admissions in local authority 1 led to an emphasis on health-service approaches, such as screening and brief intervention, whereas a public disorder focus in local authority 2 resulted in policies aimed at reducing availability through licensing measures. Perceived tensions were apparent for local authority 1 between maintaining a supportive environment for local businesses at a time of economic recession and introducing policy measures with a regulatory focus. Field observations highlighted the underlying importance of well-functioning working relationships between licensees and all responsible authorities, for achieving acceptable implementation plans for novel policies. Resource constraints and a lack of clear policy champions were also barriers to more preventive measures in local authority 1. Interpretation Devolved responsibility for alcohol harm prevention clearly presents the potential for local authorities to tailor policies closely to their identified population needs. The exercising of responsible authority status in reducing availability through licensing approaches is best achieved however when fully integrated into the full spectrum of alcohol harm reduction activities, from prevention through to treatment-based interventions

Ambipolar spin diffusion and D'yakonov-Perel' spin relaxation in GaAs quantum wells

We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum well sample at 80 K. Diffusion of electron and spin densities is simultaneously measured using a spatially and temporally resolved pump-probe technique. Two regimes of diffusion for spin-polarized electrons are observed. Initially, the rate of spin diffusion is similar to that of density diffusion and is controlled by the ambipolar diffusion coefficient. At later times, the spin diffusion slows down considerably relative to the density diffusion and appears to be controlled by a non-constant (decreasing) spin diffusion coefficient. We suggest that the long-time behavior of the spin density can be understood in terms of an inhomogeneous spin relaxation rate, which grows with decreasing density. The behavior of the spin relaxation rate is consistent with a model of D'yakonov-Perel' relaxation limited by the Coulomb scattering between carriers.Comment: 9 pages, 8 figure

[S IV] in the NGC 5253 Supernebula: Ionized Gas Kinematics at High Resolution

The nearby dwarf starburst galaxy NGC 5253 hosts a deeply embedded radio-infrared supernebula excited by thousands of O stars. We have observed this source in the 10.5{\mu}m line of S+3 at 3.8 kms-1 spectral and 1.4" spatial resolution, using the high resolution spectrometer TEXES on the IRTF. The line profile cannot be fit well by a single Gaussian. The best simple fit describes the gas with two Gaussians, one near the galactic velocity with FWHM 33.6 km s-1 and another of similiar strength and FWHM 94 km s-1 centered \sim20 km s-1 to the blue. This suggests a model for the supernebula in which gas flows towards us out of the molecular cloud, as in a "blister" or "champagne flow" or in the HII regions modelled by Zhu (2006).Comment: Accepted for publication in the Astrophysical Journal 4 June 201

Two-component magnetohydrodynamical outflows around young stellar objects Interplay between stellar magnetospheric winds and disc-driven jets

We present the first-ever simulations of non-ideal magnetohydrodynamical (MHD) stellar magnetospheric winds coupled with disc-driven jets where the resistive and viscous accretion disc is self-consistently described. These innovative MHD simulations are devoted to the study of the interplay between a stellar wind (having different ejection mass rates) and an MHD disc-driven jet embedding the stellar wind. The transmagnetosonic, collimated MHD outflows are investigated numerically using the VAC code. We first investigate the various angular momentum transports occurring in the magneto-viscous accretion disc. We then analyze the modifications induced by the interaction between the two components of the outflow. Our simulations show that the inner outflow is accelerated from the central object's hot corona thanks to both the thermal pressure and the Lorentz force. In our framework, the thermal acceleration is sustained by the heating produced by the dissipated magnetic energy due to the turbulence. Conversely, the outflow launched from the resistive accretion disc is mainly accelerated by the magneto-centrifugal force.}{The simulations show that the MHD disc-driven outflow extracts angular momentum more efficiently than do viscous effects in near-equipartition, thin-magnetized discs where turbulence is fully developed. We also show that, when a dense inner stellar wind occurs, the resulting disc-driven jet has a different structure, namely a magnetic structure where poloidal magnetic field lines are more inclined because of the pressure caused by the stellar wind. This modification leads to both an enhanced mass-ejection rate in the disc-driven jet and a larger radial extension that is in better agreement with the observations, besides being more consistent.Comment: 16 pages, Accepted in A&A 04/08/200

Controlling the collimation and rotation of hydromagnetic disk winds

(Abriged) We present a comprehensive set of axisymmetric, time-dependent simulations of jets from Keplerian disks whose mass loading as a function of disk radius is systematically changed. For a reasonable model for the density structure and injection speed of the underlying accretion disk, mass loading is determined by the radial structure of the disk's magnetic field structure. We vary this structure by using four different magnetic field configurations, ranging from the "potential" configuration (Ouyed&Pudritz 1997), to the increasingly more steeply falling Blandford&Payne (1982) and Pelletier&Pudritz (1992) models, and ending with a quite steeply raked configuration that bears similarities to the Shu X-wind model. We find that the radial distribution of the mass load has a profound effect on both the rotational profile of the underlying jet as well as the degree of collimation of its outflow velocity and magnetic field lines. We show analytically, and confirm by our simulations, that the collimation of a jet depends on its radial current distribution, which in turn is prescribed by the mass load. Models with steeply descending mass loads have strong toroidal fields, and these collimate to cylinders (this includes the Ouyed-Pudritz and Blandford-Payne outflows). On the other hand, the more gradually descending mass load profiles (the PP92 and monopolar distributions) have weaker toroidal fields, and these result in wide-angle outflows with parabolic collimation. We also present detailed structural information about jets such as their radial profiles of jet density, toroidal magnetic field, and poloidal jet speed, as well as an analysis of the bulk energetics of our different simulations.Comment: 20 journal pages, including 9 figures. Submitted to MNRA

Launching of Conical Winds and Axial Jets from the Disk-Magnetosphere Boundary: Axisymmetric and 3D Simulations

We investigate the launching of outflows from the disk-magnetosphere boundary of slowly and rapidly rotating magnetized stars using axisymmetric and exploratory 3D magnetohydrodynamic (MHD) simulations. We find long-lasting outflows in both cases. (1) In the case of slowly rotating stars, a new type of outflow, a conical wind, is found and studied in simulations. The conical winds appear in cases where the magnetic flux of the star is bunched up by the disk into an X-type configuration. The winds have the shape of a thin conical shell with a half-opening angle 30-40 degrees. The conical winds may be responsible for episodic as well as long-lasting outflows in different types of stars. (2) In the case of rapidly rotating stars (the "propeller regime"), a two-component outflow is observed. One component is similar to the conical winds. A significant fraction of the disk matter may be ejected into the winds. A second component is a high-velocity, low-density magnetically dominated axial jet where matter flows along the opened polar field lines of the star. The jet has a mass flux about 10% that of the conical wind, but its energy flux (dominantly magnetic) can be larger than the energy flux of the conical wind. The jet's angular momentum flux (also dominantly magnetic) causes the star to spin-down rapidly. Propeller-driven outflows may be responsible for the jets in protostars and for their rapid spin-down. The jet is collimated by the magnetic force while the conical winds are only weakly collimated in the simulation region.Comment: 29 pages and 29 figures. This version has a major expansion after comments by a referee. The 1-st version is correct but mainly describes the conical wind. This version describes in greater detail both the conical winds and the propeller regime. Accepted to the MNRA