8,388 research outputs found
Retailing under resale price maintenance: economies of scale and scope, and firm strategic response, in the inter-war British retail pharmacy sector
The article examines the impact of resale price maintenance (RPM) on market structure, productivity, and competitive advantage in British retail pharmacy. In contrast to influential studies, but consistent with contemporary and recent work, it is shown that the major multiples were able to ameliorate the negative growth impacts of RPM. Higher profit margins ‒ principally from larger manufacturer discounts and backward integration – were used to fund initiatives aimed at boosting aggregate sales and economies of scale and scope. These relationships are explored using a recently discovered national establishment-level survey of retail pharmacists’ costs and margins, together with internal data for Boots Ltd
Simulated X-ray Cluster Temperature Maps
Temperature maps are presented of the 9 largest clusters in the mock
catalogues of Muanwong et al. for both the Preheating and Radiative models. The
maps show that clusters are not smooth, featureless systems, but contain a
variety of substructure which should be observable. The surface brightness
contours are generally elliptical and features that are seen include cold
clumps, hot spiral features, and cold fronts. Profiles of emission-weighted
temperature, surface brightness and emission-weighted pressure across the
surface brightness discontinuities seen in one of the bimodal clusters are
consistent with the cold front in Abell 2142 observed by Markevitch et al.Comment: Submitted to Monthly Notices Royal Astronomical Societ
Abundance, distribution, and habitat of leatherback turtles (Dermochelys coriacea) off California, 1990−2003
Leatherback turtles (Dermochelys coriacea) are regularly seen off the U.S. West Coast, where they forage on jellyfish (Scyphomedusae) during summer and fall. Aerial line-transect surveys were conducted in neritic waters (<92 m depth) off central and northern California during 1990−2003, providing the first foraging population estimates for Pacific leatherback turtles. Males and females of about 1.1 to 2.1 m length were observed. Estimated abundance was linked to the Northern Oscillation Index and ranged from 12 (coefficient of variation [CV] =0.75) in 1995 to 379 (CV= 0.23) in 1990, averaging 178 (CV= 0.15). Greatest densities were found off central California, where oceanographic retention areas or upwelling shadows created favorable habitat for leatherback turtle prey. Results from independent telemetry studies have linked leatherback turtles off the U.S. West Coast to one of the two largest remaining Pacific breeding populations, at Jamursba Medi, Indonesia. Nearshore waters off California thus represent an important foraging region for the critically endangered Pacific leatherback turtle
Bringing radio into America's homes: marketing new technology in the Great Depression
We examine the early marketing and distribution of entertainment radio sets. Manufacturers used distribution networks to both maximize profits and create barriers to entry. Lacking the market power of auto manufacturers, they developed cooperative strategies with authorized distributors and dealers. Dealers often complained about the costly activities manufacturers required of them. However, these underpinned the dominant quality and branding competition model of the 1920s, while the Depression-era switch to a simpler radio format, sold on price, proved catastrophic for the specialist retailer
Radio Afterglows of Gamma-Ray Bursts and Hypernovae at High Redshift, and their Potential for 21-cm Absorption Studies
We investigate the radio afterglows of gamma-ray bursts (GRBs) and hypernovae
(HNe) at high redshifts and quantify their detectability, as well as their
potential usefulness for 21 cm absorption line studies of the intergalactic
medium (IGM) and intervening structures. We examine several sets of source and
environment model parameters that are physically plausible at high redshifts.
The radio afterglows of GRBs would be detectable out to z ~ 30, while the
energetic HNe could be detectable out to z ~ 20 even by the current Very Large
Array (VLA). We find that the 21 cm absorption line due to the diffuse neutral
IGM is difficult to detect even by the proposed Square Kilometer Array (SKA),
except for highly energetic sources. We also find that the 21 cm line due to
collapsed gas clouds with high optical depth may be detected on rare occasions.Comment: 36 pages, 12 figures, 1 table, accepted for publication in Ap
Baseline Outlook for Missouri Representative Farms 2006-2010
This report presents a five-year outlook for the set of 36 Missouri representative farms using the FAPRI 2006 U.S. Baseline.This material is based on work supported by the Cooperative State Research Education and Extension Service, U.S. Department of Agriculture, under agreement no. 2004-34228-14502
The Sunyaev-Zel'dovich temperature of the intracluster medium
The relativistic Sunyaev-Zel'dovich (SZ) effect offers a method, independent
of X-ray, for measuring the temperature of the intracluster medium (ICM) in the
hottest systems. Here, using N-body/hydrodynamic simulations of three galaxy
clusters, we compare the two quantities for a non-radiative ICM, and for one
that is subject both to radiative cooling and strong energy feedback from
galaxies. Our study has yielded two interesting results. Firstly, in all cases,
the SZ temperature is hotter than the X-ray temperature and is within ten per
cent of the virial temperature of the cluster. Secondly, the mean SZ
temperature is less affected by cooling and feedback than the X-ray
temperature. Both these results can be explained by the SZ temperature being
less sensitive to the distribution of cool gas associated with cluster
substructure. A comparison of the SZ and X-ray temperatures (measured for a
sample of hot clusters) would therefore yield interesting constraints on the
thermodynamic structure of the intracluster gas.Comment: This version accepted for publication in MNRAS following minor
revisio
Robust Detection of Dynamic Community Structure in Networks
We describe techniques for the robust detection of community structure in
some classes of time-dependent networks. Specifically, we consider the use of
statistical null models for facilitating the principled identification of
structural modules in semi-decomposable systems. Null models play an important
role both in the optimization of quality functions such as modularity and in
the subsequent assessment of the statistical validity of identified community
structure. We examine the sensitivity of such methods to model parameters and
show how comparisons to null models can help identify system scales. By
considering a large number of optimizations, we quantify the variance of
network diagnostics over optimizations (`optimization variance') and over
randomizations of network structure (`randomization variance'). Because the
modularity quality function typically has a large number of nearly-degenerate
local optima for networks constructed using real data, we develop a method to
construct representative partitions that uses a null model to correct for
statistical noise in sets of partitions. To illustrate our results, we employ
ensembles of time-dependent networks extracted from both nonlinear oscillators
and empirical neuroscience data.Comment: 18 pages, 11 figure
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