857 research outputs found
Combating CVD in Kazakhstan through workplace interventions
The project designs and tests a multifaceted worksite intervention protocol that includes
smoking cessation, dietary instruction, and exercise regimens to lower the prevalence of CVD morbidity
and mortality in Kazakhstan. Kazakhstan has among the highest CVD morbidity and mortality rates in
the world. Development of an effective worksite intervention model that targets and improves the health
behaviors and health status of high-risk middle age working males can be extended to the Republic's
crucial and expanding workplace environment
Combating CVD in Kazakhstan through workplace interventions
The project designs and tests a multifaceted worksite intervention protocol that includes
smoking cessation, dietary instruction, and exercise regimens to lower the prevalence of CVD morbidity
and mortality in Kazakhstan. Kazakhstan has among the highest CVD morbidity and mortality rates in
the world. Development of an effective worksite intervention model that targets and improves the health
behaviors and health status of high-risk middle age working males can be extended to the Republic's
crucial and expanding workplace environment
N-body simulations in modified Newtonian dynamics
We describe some results obtained with N-MODY, a code for N-body simulations
of collisionless stellar systems in modified Newtonian dynamics (MOND). We
found that a few fundamental dynamical processes are profoundly different in
MOND and in Newtonian gravity with dark matter. In particular, violent
relaxation, phase mixing and galaxy merging take significantly longer in MOND
than in Newtonian gravity, while dynamical friction is more effective in a MOND
system than in an equivalent Newtonian system with dark matter.Comment: 4 pages, no figures. To appear in EAS Publication Series (Proceedings
of Symposium 7 of the JENAM 2008, Vienna
The inverse-Compton ghost HDF 130 and the giant radio galaxy 6C 0905+3955: matching an analytic model for double radio source evolution
We present new GMRT observations of HDF 130, an inverse-Compton (IC) ghost of
a giant radio source that is no longer being powered by jets. We compare the
properties of HDF 130 with the new and important constraint of the upper limit
of the radio flux density at 240 MHz to an analytic model. We learn what values
of physical parameters in the model for the dynamics and evolution of the radio
luminosity and X-ray luminosity (due to IC scattering of the cosmic microwave
background (CMB)) of a Fanaroff-Riley II (FR II) source are able to describe a
source with features (lobe length, axial ratio, X-ray luminosity, photon index
and upper limit of radio luminosity) similar to the observations. HDF 130 is
found to agree with the interpretation that it is an IC ghost of a powerful
double-lobed radio source, and we are observing it at least a few Myr after jet
activity (which lasted 5--100 Myr) has ceased. The minimum Lorentz factor of
injected particles into the lobes from the hotspot is preferred to be
for the model to describe the observed quantities well,
assuming that the magnetic energy density, electron energy density, and lobe
pressure at time of injection into the lobe are linked by constant factors
according to a minimum energy argument, so that the minimum Lorentz factor is
constrained by the lobe pressure. We also apply the model to match the features
of 6C 0905+3955, a classical double FR II galaxy thought to have a low-energy
cutoff of in the hotspot due to a lack of hotspot
inverse-Compton X-ray emission. The models suggest that the low-energy cutoff
in the hotspots of 6C 0905+3955 is , just slightly above
the particles required for X-ray emission.Comment: 9 pages, 3 figure
Novel Microdialysis Technique Reveals a Dramatic Shift in Metabolite Secretion during the Early Stages of the Interaction between the Ectomycorrhizal Fungus Pisolithus microcarpus and Its Host Eucalyptus grandis
The colonisation of tree roots by ectomycorrhizal (ECM) fungi is the result of numerous signalling exchanges between organisms, many of which occur before physical contact. However, information is lacking about these exchanges and the compounds that are secreted by each organism before contact. This is in part due to a lack of low disturbance sampling methods with sufficient temporal and spatial resolution to capture these exchanges. Using a novel in situ microdialysis approach, we sampled metabolites released from Eucalyptus grandis and Pisolithus microcarpus independently and during indirect contact over a 48-h time-course using UPLC-MS. A total of 560 and 1530 molecular features (MFs; ESI- and ESI+ respectively) were identified with significant differential abundance from control treatments. We observed that indirect contact between organisms altered the secretion of MFs to produce a distinct metabolomic profile compared to either organism independently. Many of these MFs were produced within the first hour of contact and included several phenylpropanoids, fatty acids and organic acids. These findings show that the secreted metabolome, particularly of the ECM fungus, can rapidly shift during the early stages of pre-symbiotic contact and highlight the importance of observing these early interactions in greater detail. We present microdialysis as a useful tool for examining plant-fungal signalling with high temporal resolution and with minimal experimental disturbance
Managing risks to drivers in road transport
This report presents a number of case studies in managing risks to road transport drivers. The cases feature a variety of initiatives and interventions to protect drivers.In the road transport sector, as with any other, it is important to pay attention to working conditions in order to ensure a skilled and motivated workforce. Certain characteristics of the sector make it more difficult to practice risk management than in other sectors. But by taking account of how the sector operates in practice, and the characteristics of drivers themselves and the way they work, risks can be successfully manage
Measuring the Cluster Magnetic Field Power Spectra from Faraday Rotation Maps of Abell 400, Abell 2634 and Hydra A
We apply a novel technique of Faraday Rotation measure (RM) map analysis to
three galaxy clusters, Abell 400, Abell 2634 and Hydra A, in order to estimate
cluster magnetic field strengths, length scales and power spectra. This
analysis is based on the assumption that the magnetic fields are statistically
isotropically distributed across the Faraday screen. We investigate the
difficulties involved in the application of the analysis to observational data.
We derive magnetic power spectra for the three clusters and discuss influences
on their shapes. We show that magnetic fluctuations are probed on length scales
ranging over at least one order of magnitude. Using this range for the
determination of central cluster magnetic field strength yields 3 muG in Abell
2634, 6 muG in Abell 400 and 12 muG in Hydra A. The magnetic field
autocorrelation length was determined to be 4.9 kpc for Abell 2634, 3.6 kpc for
Abell 400 and 0.9 kpc for Hydra A. We show that the RM autocorrelation length
is larger than the magnetic field autocorrelation length. We investigate in a
response analysis if it is possible to determine spectral slopes of the power
spectra. We find that integrated numbers can be determined from this analysis
but differential parameters such as spectral slopes have to be treated
differently. Our response analysis results in spectral slopes of the power
spectra of spectral indices alpha = 1.6 to 2.0 suggesting that Kolmogorov
spectra are possible but flatter spectral slopes than alpha = 1.3 can be
excluded.Comment: 14 pages, 9 figures, accepted by A&
Non-Fermi liquid normal state of the Heavy Fermion superconductor UBe13
Non-Fermi liquid (NFL) behavior in the normal state of the heavy-fermion
superconductor UBe13 is studied by means of low-temperature measurements of the
specific heat, C, and electrical resistivity, \rho, on a high-quality single
crystal in magnetic fields up to 15.5 T. At B=0, unconventional
superconductivity forms at Tc=0.9 K out of an incoherent state, characterized
by a large and strongly temperature dependent \rho(T). In the magnetic field
interval 4 T \leq B \leq 10 T, \rho(T) follows a T^3/2 behavior for Tc(B)\leq T
\leq 1 K, while \rho is proportional to T at higher temperatures. Corresponding
Non-Fermi liquid behavior is observed in C/T as well and hints at a nearby
antiferromagnetic (AF) quantum critical point (QCP) covered by the
superconducting state. We speculate that the suppression of short-range AF
correlations observed by thermal expansion and specific heat measurements below
T_L \simeq 0.7 K (B=0) yields a field-induced QCP, T_L \to 0, at B=4.5 T.Comment: Presented at the M2S-2003 conference in Rio / Brazi
To Trust or Distrust Trust Measures: Validating Questionnaires for Trust in AI
Despite the importance of trust in human-AI interactions, researchers must
adopt questionnaires from other disciplines that lack validation in the AI
context. Motivated by the need for reliable and valid measures, we investigated
the psychometric quality of two trust questionnaires, the Trust between People
and Automation scale (TPA) by Jian et al. (2000) and the Trust Scale for the AI
Context (TAI) by Hoffman et al. (2023). In a pre-registered online experiment
(N = 1485), participants observed interactions with trustworthy and
untrustworthy AI (autonomous vehicle and chatbot). Results support the
psychometric quality of the TAI while revealing opportunities to improve the
TPA, which we outline in our recommendations for using the two questionnaires.
Furthermore, our findings provide additional empirical evidence of trust and
distrust as two distinct constructs that may coexist independently. Building on
our findings, we highlight the opportunities and added value of measuring both
trust and distrust in human-AI research and advocate for further work on both
constructs
Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands
Positive plant diversity-productivity relationships have been reported for experimental semi-natural grasslands (Cardinale et al. 2006; Hector et al. 1999; Tilman et al. 1996) as well as temporary agricultural grasslands (Frankow-Lindberg et al. 2009; Kirwan et al. 2007; Nyfeler et al. 2009; Picasso et al. 2008). Generally, these relationships are explained, on the one hand, by niche differentiation and facilitation (Hector et al. 2002; Tilman et al. 2002) and, on the other hand, by greater probability of including a highly productive plant species in high diversity plots (Huston 1997). Both explanations accept that diversity is significant because species differ in characteristics, such as root architecture, nutrient acquisition and water use efficiency, to name a few, resulting in composition and diversity being important for improved productivity and resource use (Naeem et al. 1994; Tilman et al. 2002). Plant diversity is generally low in temporary agricultural grasslands grown for ruminant fodder production. Grass in pure stands is common, but requires high nitrogen (N) inputs. In terms of N input, two-species grass-legume mixtures are more sustainable than grass in pure stands and consequently dominate low N input grasslands (Crews and Peoples 2004; Nyfeler et al. 2009; Nyfeler et al. 2011).
In temperate grasslands, N is often the limiting factor for productivity (Whitehead 1995). Plant available soil N is generally concentrated in the upper soil layers, but may leach to deeper layers, especially in grasslands that include legumes (Scherer-Lorenzen et al. 2003) and under conditions with surplus precipitation (Thorup-Kristensen 2006). To improve soil N use efficiency in temporary grasslands, we propose the addition of deep-rooting plant species to a mixture of perennial ryegrass and white clover, which are the most widespread forage plant species in temporary grasslands in a temperate climate (Moore 2003). Perennial ryegrass and white clover possess relatively shallow root systems (Kutschera and Lichtenegger 1982; Kutschera and Lichtenegger 1992) with effective rooting depths of <0.7 m on a silt loamy site (Pollock and Mead 2008). Grassland species, such as lucerne and chicory, grow their tap-roots into deep soil layers and exploit soil nutrients and water in soil layers that the commonly grown shallow-rooting grassland species cannot reach (Braun et al. 2010; Skinner 2008). Chicory grown as a catch crop after barley reduced the inorganic soil N down to 2.5 m depth during the growing season, while perennial ryegrass affected the inorganic soil N only down to 1 m depth (Thorup-Kristensen 2006). Further, on a Wakanui silt loam in New Zealand chicory extracted water down to 1.9 m and lucerne down to 2.3 m soil depth, which resulted in greater herbage yields compared with a perennial ryegrass-white clover mixture, especially for dryland plots (Brown et al. 2005).
There is little information on both the ability of deep- and shallow-rooting grassland species to access soil N from different vertical soil layers and the relation of soil N-access and herbage yield in temporary agricultural grasslands. Therefore, the objective of the present work was to test the hypotheses 1) that a mixture comprising both shallow- and deep-rooting plant species has greater herbage yields than a shallow-rooting binary mixture and pure stands, 2) that deep-rooting plant species (chicory and lucerne) are superior in accessing soil N from 1.2 m soil depth compared with shallow-rooting plant species, 3) that shallow-rooting plant species (perennial ryegrass and white clover) are superior in accessing soil N from 0.4 m soil depth compared with deep-rooting plant species, 4) that a mixture of deep- and shallow-rooting plant species has greater access to soil N from three soil layers compared with a shallow-rooting two-species mixture and that 5) the leguminous grassland plants, lucerne and white clover, have a strong impact on grassland N acquisition, because of their ability to derive N from the soil and the atmosphere
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