497 research outputs found
Financial health - how do you measure up?
Financial economics is based on the tenets that we prefer more to less and that we seek to maximise our wealth in order to maximise our happiness. Performance appraisal merely seeks measures of how well we have achieved this objective. If my tax paid wealth at the start of a period was 110 how have I done? I’ve earned 10% for sure, but just how well I have performed depends on what other people have earned having invested similar amounts in assets
of similar risk and whether this year’s earning is an improvement on previous years. In principle it is no different when assessing the overall performance of a dairy farm. Sure, there are a lot of other things to take into account, but basically the increase in wealth relative to our investment at the start of the period represents our overall return
Electron transport properties of sub-3-nm diameter copper nanowires
Density functional theory and density functional tight-binding are applied to
model electron transport in copper nanowires of approximately 1 nm and 3 nm
diameters with varying crystal orientation and surface termination. The copper
nanowires studied are found to be metallic irrespective of diameter, crystal
orientation and/or surface termination. Electron transmission is highly
dependent on crystal orientation and surface termination. Nanowires oriented
along the [110] crystallographic axis consistently exhibit the highest electron
transmission while surface oxidized nanowires show significantly reduced
electron transmission compared to unterminated nanowires. Transmission per unit
area is calculated in each case, for a given crystal orientation we find that
this value decreases with diameter for unterminated nanowires but is largely
unaffected by diameter in surface oxidized nanowires for the size regime
considered. Transmission pathway plots show that transmission is larger at the
surface of unterminated nanowires than inside the nanowire and that
transmission at the nanowire surface is significantly reduced by surface
oxidation. Finally, we present a simple model which explains the transport per
unit area dependence on diameter based on transmission pathways results
Using Group Model Building to Understand Factors That Influence Childhood Obesity in an Urban Environment
Background: Despite increased attention, conventional views of obesity are based upon individual behaviors, and children and parents living with obesity are assumed to be the primary problem solvers. Instead of focusing exclusively on individual reduction behaviors for childhood obesity, greater focus should be placed on better understanding existing community systems and their effects on obesity. The Milwaukee Childhood Obesity Prevention Project is a community-based coalition established to develop policy and environmental change strategies to impact childhood obesity in Milwaukee, Wisconsin. The coalition conducted a Group Model Building exercise to better understand root causes of childhood obesity in its community. Methods: Group Model Building is a process by which a group systematically engages in model construction to better understand the systems that are in place. It helps participants make their mental models explicit through a careful and consistent process to test assumptions. This process has 3 main components: (1) assembling a team of participants; (2) conducting a behavior-over-time graphs exercise; and (3) drawing the causal loop diagram exercise. Results: The behavior-over-time graph portion produced 61 graphs in 10 categories. The causal loop diagram yielded 5 major themes and 7 subthemes. Conclusions: Factors that influence childhood obesity are varied, and it is important to recognize that no single solution exists. The perspectives from this exercise provided a means to create a process for dialogue and commitment by stakeholders and partnerships to build capacity for change within the community
Radio Sources from a 31 GHz Sky Survey with the Sunyaev-Zel'dovich Array
We present the first sample of 31-GHz selected sources to flux levels of 1
mJy. From late 2005 to mid 2007, the Sunyaev-Zel'dovich Array (SZA) observed
7.7 square degrees of the sky at 31 GHz to a median rms of 0.18 mJy/beam. We
identify 209 sources at greater than 5 sigma significance in the 31 GHz maps,
ranging in flux from 0.7 mJy to ~200 mJy. Archival NVSS data at 1.4 GHz and
observations at 5 GHz with the Very Large Array are used to characterize the
sources. We determine the maximum-likelihood integrated source count to be
N(>S) = (27.2 +- 2.5) deg^-2 x (S_mJy)^(-1.18 +- 0.12) over the flux range 0.7
- 15 mJy. This result is significantly higher than predictions based on 1.4-GHz
selected samples, a discrepancy which can be explained by a small shift in the
spectral index distribution for faint 1.4-GHz sources. From comparison with
previous measurements of sources within the central arcminute of massive
clusters, we derive an overdensity of 6.8 +- 4.4, relative to field sources.Comment: 13 pages, 5 figure
Effect of Carbohydrate-Protein Supplement Timing on Acute Exercise-Induced Muscle Damage
Purpose:
To determine if timing of a supplement would have an effect on muscle damage, function and soreness.
Methods:
Twenty-seven untrained men (21 ± 3 yrs) were given a supplement before or after exercise. Subjects were randomly assigned to a pre exercise (n = 9), received carbohydrate/protein drink before exercise and placebo after, a post exercise (n = 9), received placebo before exercise and carbohydrate/protein drink after, or a control group (n = 9), received placebo before and after exercise. Subjects performed 50 eccentric quadriceps contractions on an isokinetic dynamometer. Tests for creatine kinase (CK), maximal voluntary contraction (MVC) and muscle soreness were recorded before exercise and at six, 24, 48, 72, and 96 h post exercise. Repeated measures ANOVA were used to analyze data.
Results:
There were no group by time interactions however, CK significantly increased for all groups when compared to pre exercise (101 ± 43 U/L) reaching a peak at 48 h (661 ± 1178 U/L). MVC was significantly reduced at 24 h by 31.4 ± 14.0%. Muscle soreness was also significantly increased from pre exercise peaking at 48 h.
Conclusion:
Eccentric exercise caused significant muscle damage, loss of strength, and soreness; however timing of ingestion of carbohydrate/protein supplement had no effect
The XXL Survey V: Detection of the Sunyaev-Zel'dovich effect of the Redshift 1.9 Galaxy Cluster XLSSU J021744.1-034536 with CARMA
We report the detection of the Sunyaev-Zel'dovich (SZ) effect of galaxy
cluster XLSSU J021744.1-034536, using 30 GHz CARMA data. This cluster was
discovered via its extended X-ray emission in the XMM-Newton Large Scale
Structure survey, the precursor to the XXL survey. It has a photometrically
determined redshift , making it among the most distant
clusters known, and nominally the most distant for which the SZ effect has been
measured. The spherically integrated Comptonization is
, a measurement which is relatively
insensitive to assumptions regarding the size and redshift of the cluster, as
well as the background cosmology. Using a variety of locally calibrated cluster
scaling relations extrapolated to z~2, we estimate a mass - from the X-ray flux and SZ signal. The measured
properties of this cluster are in good agreement with the extrapolation of an
X-ray luminosity-SZ effect scaling relation calibrated from clusters discovered
by the South Pole Telescope at higher masses and lower redshifts. The full
XXL-CARMA sample will provide a more complete, multi-wavelength census of
distant clusters in order to robustly extend the calibration of cluster scaling
relations to these high redshifts.Comment: ApJ, in press. 9 pages, 4 figures, 4 table
CARMA Measurements of the Sunyaev-Zel'dovich Effect in RXJ1347.5-1145
We demonstrate the Sunyaev-Zel'dovich (SZ) effect imaging capabilities of the
Combined Array for Research in Millimeter-wave Astronomy (CARMA) by presenting
an SZ map of the galaxy cluster RXJ1347.5-1145. By combining data from multiple
CARMA bands and configurations, we are able to capture the structure of this
cluster over a wide range of angular scales, from its bulk properties to its
core morphology. We find that roughly 9% of this cluster's thermal energy is
associated with sub-arcminute-scale structure imparted by a merger,
illustrating the value of high-resolution SZ measurements for pursuing cluster
astrophysics and for understanding the scatter in SZ scaling relations. We also
find that the cluster's SZ signal is lower in amplitude than suggested by a
spherically-symmetric model derived from X-ray data, consistent with
compression along the line of sight relative to the plane of the sky. Finally,
we discuss the impact of upgrades currently in progress that will further
enhance CARMA's power as an SZ imaging instrument.Comment: 8 pages, 6 figure
Constraints on the Thermal Contents of the X-ray Cavities of Cluster MS 0735.6+7421 with Sunyaev-Zel'dovich Effect Observations
Outbursts from active galactic nuclei (AGN) can inflate cavities in the
intracluster medium (ICM) of galaxy clusters and are believed to play the
primary role in offsetting radiative cooling in the ICM. However, the details
of how the energy from AGN feedback thermalizes to heat the ICM is not well
understood, partly due to the unknown composition and energetics of the
cavities. The Sunyaev-Zel'dovich (SZ) effect, a measure of the integrated
pressure along the line of sight, provides a means of measuring the thermal
contents of the cavities, to discriminate between thermal, nonthermal, and
other sources of pressure support. Here we report measurements of the SZ effect
at 30 GHz toward the galaxy cluster MS 0735.6+7421 (MS0735), using the Combined
Array for Research in Millimeter-wave Astronomy (CARMA). MS0735 hosts the most
energetic AGN outburst known and lobes of radio synchrotron emission coincident
with a pair of giant X-ray cavities across. Our CARMA maps show a
clear deficit in the SZ signal coincident with the X-ray identified cavities,
when compared to a smooth X-ray derived pressure model. We find that the
cavities have very little SZ-contributing material, suggesting that they are
either supported by very diffuse thermal plasma with temperature in excess of
hundreds of keV, or are not supported thermally. Our results represent the
first detection (with significance) of this phenomenon with the SZ
effect.Comment: 15 pages, 9 figures, submitted to ApJ Jun 2018, Accepted Dec 2018,
Published Jan 2019. This is the version of the article before editing, as
submitted by an author to ApJ. IOP Publishing Ltd is not responsible for any
errors or omissions in this version of the manuscript or any version derived
from it. The Version of Record is available online at
https://doi.org/10.3847/1538-4357/aaf88
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