1,341 research outputs found
Capability in the digital: institutional media management and its dis/contents
This paper explores how social media spaces are occupied, utilized and negotiated by the British Military in relation to the Ministry of Defence’s concerns and conceptualizations of risk. It draws on data from the DUN Project to investigate the content and form of social media about defence through the lens of ‘capability’, a term that captures and describes the meaning behind multiple representations of the military institution. But ‘capability’ is also a term that we hijack and extend here, not only in relation to the dominant presence of ‘capability’ as a representational trope and the extent to which it is revealing of a particular management of social media spaces, but also in relation to what our research reveals for the wider digital media landscape and ‘capable’ digital methods. What emerges from our analysis is the existence of powerful, successful and critically long-standing media and reputation management strategies occurring within the techno-economic online structures where the exercising of ‘control’ over the individual – as opposed to the technology – is highly effective. These findings raise critical questions regarding the extent to which ‘control’ and management of social media – both within and beyond the defence sector – may be determined as much by cultural, social, institutional and political influence and infrastructure as the technological economies. At a key moment in social media analysis, then, when attention is turning to the affordances, criticisms and possibilities of data, our research is a pertinent reminder that we should not forget the active management of content that is being similarly, if not equally, effective
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Splanchnic metabolism of nutrients and hormones in steers fed alfalfa under conditions of increased absorption of ammonia and L-arginine supply across the portal-drained viscera
Effects of increased ammonia and/or arginine
absorption on net splanchnic (portal-drained viscera
[PDV] plus liver) metabolism of nonnitrogenous
nutrients and hormones in cattle were examined. Six
Hereford × Angus steers (501 ± 1 kg BW) prepared with
vascular catheters for measurements of net flux across
the splanchnic bed were fed a 75% alfalfa:25% (as-fed
basis) corn and soybean meal diet (0.523 MJ of ME/[kg
BW0.75.d]) every 2 h without (27.0 g of N/kg of DM) and
with 20 g of urea/kg of DM (35.7 g of N/kg of DM) in a
split-plot design. Net flux measurements were made
immediately before and after a 72-h mesenteric vein
infusion of L-arginine (15 mmol/h). There were no treatment
effects onPDVor hepaticO2 consumption. Dietary
urea had no effect on splanchnic metabolism of glucose
or L-lactate, but arginine infusion decreased net hepatic
removal of L-lactate when urea was fed (P < 0.01). Net PDV appearance of n-butyrate was increased by arginine
infusion (P < 0.07), and both dietary urea (P <
0.09) and arginine infusion (P < 0.05) increased net
hepatic removal of n-butyrate. Dietary urea also increased
total splanchnic acetate output (P < 0.06),
tended to increase arterial glucagon concentration (P
< 0.11), and decreased arterial ST concentration (P <
0.03). Arginine infusion increased arterial concentration
(P < 0.07) and net PDV release (P < 0.10) and
tended to increase hepatic removal (P < 0.11) of insulin,
as well as arterial concentration (P < 0.01) and total
splanchnic output (P < 0.01) of glucagon. Despite
changes in splanchnic N metabolism, increased ammonia
and arginine absorption had little measurable effect
on splanchnic metabolism of glucose and other nonnitrogenous
components of splanchnic energy metabolism
Pseudoscalar Conversion and X-rays from the Sun
We investigate the detection of a pseudoscalar that couples
electromagnetically via an interaction . In
particular, we focus on the conversion of pseudoscalars produced in the sun's
interior in the presence of the sun's external magnetic dipole field and
sunspot-related magnetic fields. We find that the sunspot approach is superior.
Measurements by the SXT on the Yohkoh satellite can measure the coupling
constant down to --, provided the
pseudoscalar mass eV, which makes it competitive with
other astrophysical approaches.Comment: 15 pages, RevTex file. Figures available upon request to
[email protected]. (please include full mailing address in
request). Submitted to Physics Letters
Similar dissection of sets
In 1994, Martin Gardner stated a set of questions concerning the dissection
of a square or an equilateral triangle in three similar parts. Meanwhile,
Gardner's questions have been generalized and some of them are already solved.
In the present paper, we solve more of his questions and treat them in a much
more general context. Let be a given set and let
be injective continuous mappings. Does there exist a set such
that is satisfied with a
non-overlapping union? We prove that such a set exists for certain choices
of and . The solutions often turn out to be attractors
of iterated function systems with condensation in the sense of Barnsley. Coming
back to Gardner's setting, we use our theory to prove that an equilateral
triangle can be dissected in three similar copies whose areas have ratio
for
Interleukin-7 deficiency in rheumatoid arthritis: consequences for therapy-induced lymphopenia
We previously demonstrated prolonged, profound CD4+ T-lymphopenia in rheumatoid arthritis (RA) patients following lymphocyte-depleting therapy. Poor reconstitution could result either from reduced de novo T-cell production through the thymus or from poor peripheral expansion of residual T-cells. Interleukin-7 (IL-7) is known to stimulate the thymus to produce new T-cells and to allow circulating mature T-cells to expand, thereby playing a critical role in T-cell homeostasis. In the present study we demonstrated reduced levels of circulating IL-7 in a cross-section of RA patients. IL-7 production by bone marrow stromal cell cultures was also compromised in RA. To investigate whether such an IL-7 deficiency could account for the prolonged lymphopenia observed in RA following therapeutic lymphodepletion, we compared RA patients and patients with solid cancers treated with high-dose chemotherapy and autologous progenitor cell rescue. Chemotherapy rendered all patients similarly lymphopenic, but this was sustained in RA patients at 12 months, as compared with the reconstitution that occurred in cancer patients by 3–4 months. Both cohorts produced naïve T-cells containing T-cell receptor excision circles. The main distinguishing feature between the groups was a failure to expand peripheral T-cells in RA, particularly memory cells during the first 3 months after treatment. Most importantly, there was no increase in serum IL-7 levels in RA, as compared with a fourfold rise in non-RA control individuals at the time of lymphopenia. Our data therefore suggest that RA patients are relatively IL-7 deficient and that this deficiency is likely to be an important contributing factor to poor early T-cell reconstitution in RA following therapeutic lymphodepletion. Furthermore, in RA patients with stable, well controlled disease, IL-7 levels were positively correlated with the T-cell receptor excision circle content of CD4+ T-cells, demonstrating a direct effect of IL-7 on thymic activity in this cohort
Sunspot rotation, filament, and flare: The event on 2000 February 10
We find that a sunspot with positive polarity had an obvious
counter-clockwise rotation and resulted in the formation and eruption of an
inverse S-shaped filament in NOAA active region (AR) 08858 from 2000 February 9
to 10. The sunspot had two umbrae which rotated around each other by 195
degrees within about twenty-four hours. The average rotation rate was nearly 8
degrees per hour. The fastest rotation in the photosphere took place during
14:00UT to 22:01UT on February 9, with the rotation rate of nearly 16 degrees
per hour. The fastest rotation in the chromosphere and the corona took place
during 15:28UT to 19:00UT on February 9, with the rotation rate of nearly 20
degrees per hour. Interestingly, the rapid increase of the positive magnetic
flux just occurred during the fastest rotation of the rotating sunspot, the
bright loop-shaped structure and the filament. During the sunspot rotation, the
inverse S-shaped filament gradually formed in the EUV filament channel. The
filament experienced two eruptions. In the first eruption, the filament rose
quickly and then the filament loops carrying the cool and the hot material were
seen to spiral into the sunspot counterclockwise. About ten minutes later, the
filament became active and finally erupted. The filament eruption was
accompanied with a C-class flare and a halo coronal mass ejection (CME). These
results provide evidence that sunspot rotation plays an important role in the
formation and eruption of the sigmoidal active-region filament.Comment: 20 pages, 9 figures, Accepted for publication in Ap
Age-related differences in spontaneous trait judgments from facial appearance.
We tested whether there are age-related declines in detecting cues to trustworthiness, a skill that has been demonstrated to be rapid and automatic in younger adults. Young (age M = 21.17 years) and older (age M = 70.15 years) adults made criminal appearance judgments to unfamiliar faces, which were presented at a duration of either 100, 500, or 1000-ms. Participants’ response times and judgment confidence were recorded. Older compared to young adults were poorer at judging trustworthiness at 100-ms, and were slower overall in making their judgments. Further, the cues (i.e., perceptions of anger, trustworthiness, and happiness) underlying criminality judgments were the same across age groups. Judgment confidence increased with increasing exposure duration for both age groups, while older adults were less confident in their judgments overall than their young counterparts. The implications are discussed
Stray-light contamination and spatial deconvolution of slit-spectrograph observations
Stray light caused by scattering on optical surfaces and in the Earth's
atmosphere degrades the spatial resolution of observations. We study the
contribution of stray light to the two channels of POLIS. We test the
performance of different methods of stray-light correction and spatial
deconvolution to improve the spatial resolution post-facto. We model the stray
light as having two components: a spectrally dispersed component and a
component of parasitic light caused by scattering inside the spectrograph. We
use several measurements to estimate the two contributions: observations with a
(partly) blocked FOV, a convolution of the FTS spectral atlas, imaging in the
pupil plane, umbral profiles, and spurious polarization signal in telluric
lines. The measurements allow us to estimate the spatial PSF of POLIS and the
main spectrograph of the German VTT. We use the PSF for a deconvolution of both
spectropolarimetric data and investigate the effect on the spectra. The
parasitic contribution can be directly and accurately determined for POLIS,
amounting to about 5%. We estimate a lower limit of about 10% across the full
FOV for the dispersed stray light. In quiet Sun regions, the stray-light level
from the close surroundings (d< 2") of a given spatial point is about 20%. The
stray light reduces to below 2% at a distance of 20" from a lit area for both
POLIS and the main spectrograph. A two-component model of the stray-light
contributions seems to be sufficient for a basic correction of observed
spectra. The instrumental PSF obtained can be used to model the off-limb stray
light, to determine the stray-light contamination accurately for observation
targets with large spatial intensity gradients such as sunspots, and also
allows one to improve the spatial resolution of observations post-facto.Comment: 14 pages, 16 figures, accepted by A&A. Version V2 revised for
language editin
Developing autonomous learning in first year university students using perspectives from positive psychology
Autonomous learning is a commonly occurring learning outcome from university study, and it is argued that students require confidence in their own abilities to achieve this. Using approaches from positive psychology, this study aimed to develop confidence in first‐year university students to facilitate autonomous learning. Psychological character strengths were assessed in 214 students on day one at university. Two weeks later their top three strengths were given to them in study skills modules as part of a psycho‐educational intervention designed to increase their self‐efficacy and self‐esteem. The impact of the intervention was assessed against a control group of 40 students who had not received the intervention. The results suggested that students were more confident after the intervention, and that levels of autonomous learning increased significantly compared to the controls. Character strengths were found to be associated with self‐efficacy, self‐esteem and autonomous learning in ways that were theoretically meaningful
Resolving the Azimuthal Ambiguity in Vector Magnetogram Data with the Divergence-Free Condition: Application to Discrete Data
We investigate how the divergence-free property of magnetic fields can be
exploited to resolve the azimuthal ambiguity present in solar vector
magnetogram data, by using line-of-sight and horizontal heliographic derivative
information as approximated from discrete measurements. Using synthetic data we
test several methods that each make different assumptions about how the
divergence-free property can be used to resolve the ambiguity. We find that the
most robust algorithm involves the minimisation of the absolute value of the
divergence summed over the entire field of view. Away from disk centre this
method requires the sign and magnitude of the line-of-sight derivatives of all
three components of the magnetic field vector.Comment: Solar Physics, in press, 20 pages, 11 figure
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