153 research outputs found
On the use of haptic tablets for UGV teleoperation in unstructured environments: system design and evaluation
Teleoperation of Unmanned Ground Vehicles (UGVs), particularly for inspection of unstructured and
unfamiliar environments still raises important challenges from the point of view of the operator interface.
One of these challenges is caused by the fact that all information available to the operator is presented to the operator through a computer interface, providing only a partial view of the robot situation. The majority of existing interfaces provide information using visual, and, less frequently, sound channels. The lack of Situation Awareness (SA), caused by this partial view, may lead to an incorrect and inefficient response to the current UGV state, usually confusing and frustrating the human operator. For instance, the UGV may become stuck in debris while the operator struggles to move the robot, not understanding the cause of the UGV lack of motion. We address this problem by studying the use of haptic feedback to improve operator SA. More precisely, improving SA with respect to the traction state of the UGV, using a haptic tablet for both commanding the robot and conveying traction state to the user by haptic feedback. We report (1) a teleoperating interface, integrating a haptic tablet with an existing UGV teleoperation interface, and (2) the experimental results of a user study designed to evaluate the advantage of this interface in the teleoperation of a UGV, in a search and rescue scenario. Statistically significant results were found supporting the hypothesis that using the haptic tablet elicits a reduction in the time that the UGV spends in states without traction.info:eu-repo/semantics/publishedVersio
Dietary intakes of women with Type 1 diabetes before and during pregnancy: A preâspecified secondary subgroup analysis among CONCEPTT participants
Aim To describe the dietary intakes of women with Type 1 diabetes before and during pregnancy. Methods This was a preâspecified subgroup analysis of CONCEPTT involving 63 women planning pregnancy and 93 pregnant women from 14 sites in England, Scotland and Ireland. Two hundred and fortyâsix 3âday food diaries (104 planning pregnancy, 142 pregnant) were matched to data source and food reference codes, and analysed using dietary software. Participants were informed that food diaries would be deâidentified and used only for research purposes. Results Mean (sd) daily energy intake was 1588 (346) kcal and 1673 (384) kcal in women planning pregnancy and pregnant women respectively. Total carbohydrate intake was consistent with dietary guideline recommendations [180 (52) g planning pregnancy, 198 (54) g pregnant], but nonârecommended sources (e.g. sugars, preserves, confectionery, biscuits, cakes) contributed to 46% of total daily carbohydrate intake. Fat consumption exceeded guideline recommendations [70 (21) g planning pregnancy, 72 (21) g pregnant]. Fibre [15.5 (5.3) g planning pregnancy, 15.4 (5.1) g pregnant], fruit and vegetable intakes [3.5 (2.2) and 3.1 (1.8) serves/day] were inadequate. Twelve women planning pregnancy (19%) and 24 pregnant women (26%) did not meet micronutrient requirements. Conclusions The diets of pregnant women from England, Scotland and Ireland are characterized by high fat, low fibre and poorâquality carbohydrate intakes. Fruit and vegetable consumption is inadequate, with one in four women at risk of micronutrient deficiencies. Further research is needed to optimize maternal nutrition for glycaemic control and for maternal and offspring health
The intra-cellular localization of the vanillin biosynthetic machinery in pods of Vanilla planifolia
Vanillin is the most important flavor compound in the vanilla pod. Vanilla planifolia vanillin synthase (VpVAN) catalyzes the conversion of ferulic acid and ferulic acid glucoside into vanillin and vanillin glucoside, respectively. Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) of vanilla pod sections demonstrates that vanillin glucoside is preferentially localized within the mesocarp and placental laminae whereas vanillin is preferentially localized within the mesocarp. VpVAN is present as the mature form (25 kDa) but, depending on the tissue and isolation procedure, small amounts of the immature unprocessed form (40 kDa) and putative oligomers (50, 75 and 100 kDa) may be observed by immunoblotting using an antibody specific to the C-terminal sequence of VpVAN. The VpVAN protein is localized within chloroplasts and re-differentiated chloroplasts termed phenyloplasts, as monitored during the process of pod development. Isolated chloroplasts were shown to convert [14C]phenylalanine and [14C]cinnamic acid into [14C]vanillin glucoside, indicating that the entire vanillin de novo biosynthetic machinery converting phenylalanine to vanillin glucoside is present in the chloroplast
The evolution of the Milky Way's thin disc radial metallicity gradient with K2 asteroseismic ages
The radial metallicity distribution of the Milky Way's disc is an important
observational constraint for models of the formation and evolution of our
Galaxy. It informs our understanding of the chemical enrichment of the Galactic
disc and the dynamical processes therein, particularly radial migration. We
investigate how the metallicity changes with guiding radius in the thin disc
using a sample of red-giant stars with robust astrometric, spectroscopic and
asteroseismic parameters. Our sample contains stars with guiding radii
kpc < < kpc and asteroseismic ages covering the whole
history of the thin disc with precision . We use MCMC analysis to
measure the gradient and its intrinsic spread in bins of age and construct a
hierarchical Bayesian model to investigate the evolution of these parameters
independently of the bins. We find a smooth evolution of the gradient from
dex/kpc in the youngest stars to dex/kpc in
stars older than Gyr, with no break at intermediate ages. Our results are
consistent with those based on asteroseismic ages from CoRoT, with that found
in Cepheid variables for stars younger than Gyr, and with open clusters for
stars younger than Gyr. For older stars we find a significantly lower
metallicity in our sample than in the clusters, suggesting a survival bias
favouring more metal-rich clusters. We also find that the chemical evolution
model of Chiappini (2009) is too metal-poor in the early stages of disc
formation. Our results provide strong new constraints for the growth and
enrichment of the thin disc and radial migration, which will facilitate new
tests of model conditions and physics.Comment: 15 pages, 16 figures. Accepted for publication in MNRA
An asteroseismic age estimate of the open cluster NGC 6866 using Kepler and Gaia
Asteroseismology of solar-like oscillations in giant stars allow the
derivation of their masses and radii. For members of open clusters this allows
an age estimate of the cluster which should be identical to the age estimate
from the colour-magnitude diagram, but independent of the uncertainties that
are present for that type of analysis. Thus, a more precise and accurate age
estimate can be obtained. We aim to measure asteroseismic properties of
oscillating giant members of the open cluster NGC 6866 and utilise these for a
cluster age estimate. Model comparisons allow constraints on the stellar
physics, and here we investigate the efficiency of convective-core overshoot
and effects of rotation during the main-sequence, which has a significant
influence on the age for these relatively massive giants. We identify six giant
members of NGC 6866 and derive asteroseismic measurements for five of them.
This constrains the convective-core overshoot and enables a more precise and
accurate age estimate than previously possible. Asteroseismology establishes
the helium-core burning evolutionary phase for the giants, which have a mean
mass of 2.8 . Their radii are significantly smaller than predicted
by current 1D stellar models unless the amount of convective-core overshoot on
the main sequence is reduced to in the
step-overshoot description. Our measurements also suggest that rotation has
affected the evolution of the stars in NGC 6866 in a way that is consistent
with 3D simulations but not with current 1D stellar models. The cluster age is
estimated to be 0.43 0.05 Gyr, significantly younger and more precise
than most previous estimates. We derive a precise cluster age while
constraining convective-core overshooting and effects of rotation in the
models. We uncover potential biases for automated age estimates of helium-core
burning stars.Comment: Accepted on 21/08/2023 for publication in Section 7. Stellar
structure and evolution of Astronomy & Astrophysics. 20 Pages, 11 Figures +
appendi
K2 results for "young" -rich stars in the Galaxy
The origin of apparently young -rich stars in the Galaxy is still a
matter of debate in Galactic archaeology, whether they are genuinely young or
might be products of binary evolution and merger/mass accretion. We aim to shed
light on the nature of young -rich stars in the Milky Way by studying
their distribution in the Galaxy thanks to an unprecedented sample of giant
stars that cover different Galactic regions and have precise asteroseismic
ages, chemical, and kinematic measurements. We analyze a new sample of
6000 stars with precise ages coming from asteroseismology. Our sample combines
the global asteroseismic parameters measured from light curves obtained by the
K2 mission with stellar parameters and chemical abundances obtained from APOGEE
DR17 and GALAH DR3, then cross-matched with Gaia DR3. We define our sample of
young -rich stars and study their chemical, kinematic, and age
properties. We investigate young -rich stars in different parts of the
Galaxy and we find that the fraction of young -rich stars remains
constant with respect to the number of high- stars at 10%.
Furthermore, young -rich stars have kinematic and chemical properties
similar to high- stars, except for [C/N] ratios. This suggests that
these stars are not genuinely young, but products of binary evolution and
merger/mass accretion. Under that assumption, we find the fraction of these
stars in the field to be similar to that found recently in clusters. This fact
suggests that 10% of the low- field stars could also have their
ages underestimated by asteroseismology. This should be kept in mind when using
asteroseismic ages to interpret results in Galactic archaeology.Comment: 13 pages, 7 figures. Accepted by A&
K2 results for âyoungâ α-rich stars in the Galaxy
Context. The origin of apparently young α-rich stars in the Galaxy is still a matter of debate in Galactic archaeology, whether they are genuinely young or might be products of binary evolution, and mergers or mass accretion.Aims: Our aim is to shed light on the nature of young α-rich stars in the Milky Way by studying their distribution in the Galaxy thanks to an unprecedented sample of giant stars that cover different Galactic regions and have precise asteroseismic ages, and chemical and kinematic measurements.Methods: We analyzed a new sample of âŒ6000 stars with precise ages coming from asteroseismology. Our sample combines the global asteroseismic parameters measured from light curves obtained by the K2 mission with stellar parameters and chemical abundances obtained from APOGEE DR17 and GALAH DR3, then cross-matched with Gaia DR3. We define our sample of young α-rich stars and study their chemical, kinematic, and age properties.Results: We investigated young α-rich stars in different parts of the Galaxy and we find that the fraction of young α-rich stars remains constant with respect to the number of high-α stars at âŒ10%. Furthermore, young α-rich stars have kinematic and chemical properties similar to high-α stars, except for [C/N] ratios.Conclusions: Thanks to our new K2 sample, we conclude that young α-rich stars have similar occurrence rates in different parts of the Galaxy, and that they share properties similar to the normal high-α population, except for [C/N] ratios. This suggests that these stars are not genuinely young, but are products of binary evolution, and mergers or mass accretion. Under that assumption, we find the fraction of these stars in the field to be similar to that found recently in clusters. This suggests that âŒ10% of the low-α field stars could also have their ages underestimated by asteroseismology. This should be kept in mind when using asteroseismic ages to interpret results in Galactic archaeology
Lack of association between polymorphisms of the IL18R1 and IL18RAP genes and cardiovascular risk: the MORGAM Project
Neurophysiological evidence for rapid processing of verbal and gestural information in understanding communicative actions
During everyday social interaction, gestures are a fundamental part of human communication. The communicative pragmatic role of hand gestures and their interaction with spoken language has been documented at the earliest stage of language development, in which two types of indexical gestures are most prominent: the pointing gesture for directing attention to objects and the give-me gesture for making requests. Here we study, in adult human participants, the neurophysiological signatures of gestural-linguistic acts of communicating the pragmatic intentions of naming and requesting by simultaneously presenting written words and gestures. Already at ~150 ms, brain responses diverged between naming and request actions expressed by word-gesture combination, whereas the same gestures presented in isolation elicited their earliest neurophysiological dissociations significantly later (at ~210âms). There was an early enhancement of request-evoked brain activity as compared with naming, which was due to sources in the frontocentral cortex, consistent with access to action knowledge in request understanding. In addition, an enhanced N400-like response indicated late semantic integration of gesture-language interaction. The present study demonstrates that word-gesture combinations used to express communicative pragmatic intentions speed up the brain correlates of comprehension processes â compared with gesture-only understanding â thereby calling into question current serial linguistic models viewing pragmatic function decoding at the end of a language comprehension cascade. Instead, information about the social-interactive role of communicative acts is processed instantaneously
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