33,149 research outputs found
Social Functioning of Children and Their Parents: Are They Related?
This study examined whether parents' social support was related to their children's peer acceptance and likability. The moderating role of the parent's and the child's gender was also examined. Father (N = 146-150) and mother (N = 201) reports of social support and peer reports of peer acceptance were obtained from 107 boys and 96 girls (7.92-16.76 years, M = 11.77). Aspects of fathers' and mothers' social support were observed to be differentially correlated with their children's friendships and likability. While fathers' social support was moderately correlated with their children's friendships, mothers' social support was not. The implications of these findings for the role of fathers in children's social functioning are discussed
Sediment disturbance caused by a suspension-feeding tubular agglutinated foraminifer
We report the occurrence of in-situ sediment disturbance caused by a specimen of Rhabdammina
observed in life position on the 1991 Mt. Pinatubo ash layer in the abyssal South China Sea. The
specimen extracts sediment grains from the ash layer to build its agglutinated test, causing a
depression, or “moat” to form around the base of the specimen. We suspect that such fine-scale
disturbance caused by large, erect tubular foraminifera is a common feature of the fossil record in
deep-sea settings
A tubular protozoan predator: a burrow selectively filled with tubular agglutinated protozoans (Xenophyophorea, Foraminifera) in the abyssal South China Sea
We report the occurrence of an unusual agglutinated protozoan-filled burrow recovered in a box core
collected in 1998 from a depth of 2496 m in the South China Sea. The onion-shaped burrow
occurring some 8 cm beneath the sediment surface was packed full with specimens of
xenophyophoreans and foraminifera dominated by a single genus (Aschemonella) that had been living
on the surface of the 1991 Mt. Pinatubo ash layer. This selective scavenging of epibenthic tubular
agglutinated protozoans contributes to the patchiness of the benthic fauna on the sea floor. Because
the tubular protozoans selectively agglutinate mafic mineral grains from the volcanic ash, two levels
of biological scavenging are involved with the redistribution of these volcanic grains
Economies of Scope in European Railways: An Efficiency Analysis
In the course of railway reforms at the end of the last century, European na- tional governments, as well the EU Commission, decided to open markets and to separate railway networks from train operations. Vertically integrated railway com- panies argue that such a separation of infrastructure and operations would diminish the advantages of vertical integration and would therefore not be suitable to raise economic welfare. In this paper, we conduct a pan-European analysis to investi- gate the performance of European railways with a particular focus on economies of scope associated with vertical integration. We test the hypothesis that integrated railways realize economies of joint production and, thus, produce railway services on a higher level of efficiency. To determine whether joint or separate production is more efficient we apply an innovative Data Envelopment Analysis super-efficiency bootstrapping model which relates the efficiency for integrated production to a vir- tual reference set consisting of the separated production technology and which is applicable to other network industries as energy and telecommunication as well. Our findings are that for a majority of European Railway companies economies of scope exist.Efficiency, Vertical Integration, Railway Industry
Are Halo and Galaxy Formation Histories Correlated?
The properties of dark matter halos, including mass growth, correlate with
larger scale environment at fixed mass, an effect known as assembly bias.
However, whether this environmental dependence manifests itself in galaxy
properties remains unclear. We apply a group-finding algorithm to DR7 of the
SDSS to estimate the halo mass of each galaxy and to decompose galaxies into
those that exist at the centers of distinct halos and those that orbit as
satellites within larger halos. Using the 4000-A break as a measure of star
formation history, we examine the correlation between the quenched fraction of
galaxies, f_q, and large-scale environment, rho. At all galaxy magnitudes,
there is a positive, monotonic relationship between f_q and rho. We use the
group catalog to decompose this correlation into the contribution from central
and satellite galaxies as a function of halo mass. Because satellites are more
likely to be quenched than central galaxies, the observed f_q-rho correlation
is primarily due to variations of the halo mass function with environment,
which causes a larger fraction of satellite galaxies at high rho. For low-mass
central galaxies (Mgal <~ 10^10.0 Msol/h^2), there is no correlation between
f_q and rho. These results are inconsistent with the strong assembly bias of
dark matter halos seen in this mass regime if recent galaxy growth at all
correlates with recent halo growth, as we demonstrate through a high resolution
N-body simulation. We also find that the mean stellar age of quenched central
galaxies is independent of rho at fixed Mgal, while the formation times of low
mass halos vary significantly. We conclude that the processes that halt the
star formation of low mass central galaxies are not correlated to the formation
histories of their host halos, and old galaxies do not reside preferentially in
old halos. (Abridged)Comment: 21 pages, submitted to MNRA
The Difficulty to Behave as a (regulated) Natural Monopolist – The Dynamics of Electricity Network Access Charges in Germany 2002 to 2005
Reviewing the development of network access charges in the German electricity market since 2002 reveals significant variation. While some firms continually increased or decreased their access charges, a variety of firms exhibited discontinuousn behavior with price changes in both directions. From an economic viewpoint this price setting turbulence is astonishing because grid operators are non-contestable natural monopolists, which in this time period were regulated by Negotiated Third Party Access (NTPA). Depending on the eectiveness or ineectiveness of NTPA,expected behavior would be either regulated average cost prices or monopoly prices, but not the observed turbulence. Although in 2005 NTPA scheme was replaced by a Regulated Third Party Access (RTPA) scheme with a regulator, an analysis of the factors influencing the price setting behavior within this period oers valuable information for the new regulator and the still discussed new incentive regulation, which is expected to start in 2009. Using multivariate estimations based on firm data covering the years 2000-2005, we test the hypotheses that asymmetric influence of regulatory threat, dierent cost and price calculation knowledge, strategic use of structural features and the obligation to publish specific access charges have influenced the electricity network access charges in Germany.Keywords: deregulation, natural monopoly, power industry
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