1,697 research outputs found
Assessing the Applicability of Hofstede\u27s Cultural Dimensions for Global 500 Corporations\u27 Facebook Profiles and Content
This research examines how Hofstede’s six cultural dimensions are reflected on the official corporate Facebook pages from 259 organizations on Fortune magazine’s Global 500 list. This research is grounded in original indices to measure the six dimensions across Facebook’s “About Us” section, the textual updates provided by the companies, as well as the media that they share (photographs and videos). This is the first attempt to create a conceptualization of Hofstede’s dimensions for organizational social media use. The results paint a mixed picture indicating that the global nature of these corporations is echoed in a somewhat similar overall presence on Facebook; but when the individual elements (About Us, updates, and media) are examined, statistical differences emerge in relation to the reflection of the cultural dimensions. Limitations and directions for future research are discussed
A prototypical small-molecule modulator uncouples mitochondria in response to endogenous hydrogen peroxide production
A high membrane potential across the mitochondrial inner membrane leads to the production of the reactive oxygen species (ROS) implicated in aging and age-related diseases. A prototypical drug for the correction of this type of mitochondrial dysfunction is presented. MitoDNP-SUM accumulates in mitochondria in response to the membrane potential due to its mitochondria-targeting alkyltriphenylphosphonium (TPP) cation and is uncaged by endogenous hydrogen peroxide to release the mitochondrial uncoupler, 2,4-dinitrophenol (DNP). DNP is known to reduce the high membrane potential responsible for the production of ROS. The approach potentially represents a general method for the delivery of drugs to the mitochondrial matrix through mitochondria targeting and H2O2-induced uncaging
Impact of Systematic Errors in Sunyaev-Zel'dovich Surveys of Galaxy Clusters
Future high-resolution microwave background measurements hold the promise of
detecting galaxy clusters throughout our Hubble volume through their
Sunyaev-Zel'dovich (SZ) signature, down to a given limiting flux. The number
density of galaxy clusters is highly sensitive to cluster mass through
fluctuations in the matter power spectrum, as well as redshift through the
comoving volume and the growth factor. This sensitivity in principle allows
tight constraints on such quantities as the equation of state of dark energy
and the neutrino mass. We evaluate the ability of future cluster surveys to
measure these quantities simultaneously when combined with PLANCK-like CMB
data. Using a simple effective model for uncertainties in the cluster mass-SZ
flux relation, we evaluate systematic shifts in cosmological constraints from
cluster SZ surveys. We find that a systematic bias of 10% in cluster mass
measurements can give rise to shifts in cosmological parameter estimates at
levels larger than the statistical errors. Systematic errors are
unlikely to be detected from the mass and redshift dependence of cluster number
counts alone; increasing survey size has only a marginal effect. Implications
for upcoming experiments are discussed.Comment: 12 pages, 6 figures; accepted to JCAP; revised to match submitted
versio
On the weight of entanglement
We investigate a scenario where quantum correlations affect the gravitational
field. We show that quantum correlations between particles occupying different
positions have an effect on the gravitational field. We find that the small
perturbations induced by the entanglement depend on the amount of entanglement
and vanish for vanishing quantum correlations. Our results suggest that there
is a form of entanglement that has a weight, since it affects the gravitational
field. This conclusion may lead towards a new understanding of the role of
quantum correlations within the overlap of relativistic and quantum theories.Comment: 6 pages, no figures. Updated to match published versio
The Spiral Structure of the Milky Way, Cosmic Rays, and Ice Age Epochs on Earth
The short term variability of the Galactic cosmic ray flux (CRF) reaching
Earth has been previously associated with variations in the global low altitude
cloud cover. This CRF variability arises from changes in the solar wind
strength. However, cosmic ray variability also arises intrinsically from
variable activity of and motion through the Milky Way. Thus, if indeed the CRF
climate connection is real, the increased CRF witnessed while crossing the
spiral arms could be responsible for a larger global cloud cover and a reduced
temperature, thereby facilitating the occurrences of ice ages. This picture has
been recently shown to be supported by various data (Shaviv, 2001). In
particular, the variable CRF recorded in Iron meteorites appears to vary
synchronously with the appearance ice ages.
Here we expand upon the original treatment with a more thorough analysis and
more supporting evidence. In particular, we discuss the cosmic ray diffusion
model which considers the motion of the Galactic spiral arms. We also elaborate
on the structure and dynamics of the Milky Way's spiral arms. In particular, we
bring forth new argumentation using HI observations which imply that the
galactic spiral arm pattern speed appears to be that which fits the glaciation
period and the cosmic-ray flux record extracted from Iron meteorites. In
addition, we show that apparent peaks in the star formation rate history, as
deduced by several authors, coincides with particularly icy epochs, while the
long period of 1 to 2 Gyr before present, during which no glaciations are known
to have occurred, coincides with a significant paucity in the past star
formation rate.Comment: 33 pages, 11 figures. To Appear in New Astronom
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