28 research outputs found
DRIVE: Data-driven Robot Input Vector Exploration
An accurate motion model is a fundamental component of most autonomous
navigation systems. While much work has been done on improving model
formulation, no standard protocol exists for gathering empirical data required
to train models. In this work, we address this issue by proposing Data-driven
Robot Input Vector Exploration (DRIVE), a protocol that enables characterizing
uncrewed ground vehicles (UGVs) input limits and gathering empirical model
training data. We also propose a novel learned slip approach outperforming
similar acceleration learning approaches. Our contributions are validated
through an extensive experimental evaluation, cumulating over 7 km and 1.8 h of
driving data over three distinct UGVs and four terrain types. We show that our
protocol offers increased predictive performance over common human-driven
data-gathering protocols. Furthermore, our protocol converges with 46 s of
training data, almost four times less than the shortest human dataset gathering
protocol. We show that the operational limit for our model is reached in
extreme slip conditions encountered on surfaced ice. DRIVE is an efficient way
of characterizing UGV motion in its operational conditions. Our code and
dataset are both available online at this link:
https://github.com/norlab-ulaval/DRIVE.Comment: 6 pages, 7 figures, submitted to 2024 IEEE International Conference
on Robotics and Automation (ICRA 2024
Nutritional content of sliced bread available in Quebec, Canada : focus on sodium and fibre content
Bread is a highly consumed food and an important source of nutrients in the diet of Canadians, underlining the need to improve its nutritional quality. The Food Quality Observatory (Observatory) aimed to evaluate the nutritional value of the sliced bread products available in Quebec (Canada), according to their grain type and main flour. Analyses included comparing the breadâs sodium content to Health Canadaâs daily values (DV) and sodium voluntary targets, comparing the breadâs fibre content thresholds with the source of fibre mentioned, and assessing whether the main flour was associated with the nutrient content. The nutritional values of 294 sliced breads available in Quebec were merged with sales data (from October 2016 to October 2017), with 262 products successfully cross-referenced. The results showed that 64% of the breads purchased were âlowâ in fibre (i.e., below 2 g per two slices), while 47% were âhighâ in sodium (i.e., above 15% DV per two slices). Attention should be paid to 100% refined grain bread and to bread with refined flour as the main flour, since they are great sellers, while showing a less favourable nutrient content. This study shows that there is room for improvement in the nutritional content of Quebecâs bread offer, particularly regarding sodium and fibre content
Assessing nutritional value of ready-to-eat breakfast cereals in the province of Quebec (Canada) : a study from the Food Quality Observatory
Objective: The Food Quality Observatory was created in the province of Quebec (Canada) in 2016. In this study, the Observatory aimed to generate a methodology to (1) test the use of sales data combined with nutrient values to characterise the nutritional composition of ready-to-eat (RTE) breakfast cereals offered and purchased in the province of Quebec (Canada) and (2) verify the extent to which a front-of-pack label based on the percentage of daily value (DV) for total sugar, as a strategy to improve the food supply, would be distributed in this food category.
Design: Nutritional information were obtained by purchasing each RTE breakfast cereal available in the Greater Montreal area. Cereals were then classified according to their processing type.
Setting: The nutritional values of 331 RTE breakfast cereals available in Quebec were merged with sales data covering the period between May 2016 and May 2017. A total of 306 products were successfully cross-referenced.
Results: Granola and sweetened cereals were the most available (36·6 % and 19·6 %, respectively) and purchased (19·8 % and 40·9 % of sales, respectively). When compared with other types of cereals, granola cereals had a higher energy, fat, saturated fat, protein content and a lower Na content. A larger proportion of chocolate (65 %) and sweetened cereals (49 %) were above 15 % of the DV for sugar.
Conclusions: This study showed that the methodology developed generates important data to monitor nutritional quality of the food supply and ultimately contribute to improve the nutritional quality of processed foods
The 20S proteasome core, active within apoptotic exosome-like vesicles, induces autoantibody production and accelerates rejection
Autoantibodies to components of apoptotic cells, such as anti-perlecan antibodies, contribute to rejection in organ
transplant recipients. However, mechanisms of immunization to apoptotic components remain largely uncharacterized. We used large-scale proteomics, with validation by electron microscopy and biochemical methods, to compare
the protein profiles of apoptotic bodies and apoptotic exosome-like vesicles, smaller extracellular vesicles released
by endothelial cells downstream of caspase-3 activation. We identified apoptotic exosome-like vesicles as a central
trigger for production of anti-perlecan antibodies and acceleration of rejection. Unlike apoptotic bodies, apoptotic
exosome-like vesicles triggered the production of anti-perlecan antibodies in naĂŻve mice and enhanced anti-perlecan
antibody production and allograft inflammation in mice transplanted with an MHC (major histocompatibility
complex)âincompatible aortic graft. The 20S proteasome core was active within apoptotic exosome-like vesicles
and controlled their immunogenic activity. Finally, we showed that proteasome activity in circulating exosome-like
vesicles increased after vascular injury in mice. These findings open new avenues for predicting and controlling maladaptive humoral responses to apoptotic cell components that enhance the risk of rejection after transplantation
Present and Future of SLAM in Extreme Underground Environments
This paper reports on the state of the art in underground SLAM by discussing
different SLAM strategies and results across six teams that participated in the
three-year-long SubT competition. In particular, the paper has four main goals.
First, we review the algorithms, architectures, and systems adopted by the
teams; particular emphasis is put on lidar-centric SLAM solutions (the go-to
approach for virtually all teams in the competition), heterogeneous multi-robot
operation (including both aerial and ground robots), and real-world underground
operation (from the presence of obscurants to the need to handle tight
computational constraints). We do not shy away from discussing the dirty
details behind the different SubT SLAM systems, which are often omitted from
technical papers. Second, we discuss the maturity of the field by highlighting
what is possible with the current SLAM systems and what we believe is within
reach with some good systems engineering. Third, we outline what we believe are
fundamental open problems, that are likely to require further research to break
through. Finally, we provide a list of open-source SLAM implementations and
datasets that have been produced during the SubT challenge and related efforts,
and constitute a useful resource for researchers and practitioners.Comment: 21 pages including references. This survey paper is submitted to IEEE
Transactions on Robotics for pre-approva
Disinhibition: its effects on appetite and weight regulation.
yesOver the past 30 years, the understanding of eating behaviour has been dominated
by the concept of dietary restraint. However, the development of the Three Factor
Eating Questionnaire introduced two other factors, Disinhibition and Hunger,
which have not received as much recognition in the literature. The objective of this
review was to explore the relationship of the Disinhibition factor with weight
regulation, food choice and eating disorders, and to consider its aetiology. The
review indicates that Disinhibition is an important eating behaviour trait. It is
associated not only with a higher body mass index and obesity, but also with
mediating variables, such as less healthful food choices, which contribute to
overweight/obesity and poorer health. Disinhibition is also implicated in eating
disorders and contributes to eating disorder severity. It has been demonstrated
that Disinhibition is predictive of poorer success at weight loss, and of weight
regain after weight loss regimes and is associated with lower self-esteem, low
physical activity and poor psychological health. Disinhibition therefore emerges as
an important and dynamic trait, with influences that go beyond eating behaviour
and incorporate other behaviours which contribute to weight regulation and
obesity. The characteristics of Disinhibition itself therefore reflect many components
representative of a thrifty type of physiology. We propose that the trait of
Disinhibition be more appropriately renamed as Âżopportunistic eatingÂż or Âżthrifty
behaviourÂż
Colour-specific differences in attentional deployment for equiluminant pop-out colours: Evidence from lateralised potentials
We investigated how target colour affected behavioural and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralised components. Four colours (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distracters. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralised ERP components relative to the side of the lateral coloured circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colours and suggests special caution when designing ERP experiments involving stimuli in different colours, even when all colours are equiluminant
Nutritional value of child-targeted food products : results from the food quality observatory
Objective: To characterise the nutritional quality of food products targeted to children, we aimed: (1) to determine if the nutritional composition of child-targeted food products is different from those for the general population and (2) to verify differences in the nutrient content of child-targeted food products between three selected food categories.
Design: The present study is part of the work conducted by the Food Quality Observatory, created in 2016 in the province of Quebec (Canada). Ready-to-eat (RTE) breakfast cereals (n 331), granola bars (n 310) and yoghurts and dairy desserts (n 380) were the food categories analysed.
Setting: Nutritional values and all packaging information were obtained by purchasing every product available in supermarkets, grocery stores and specialty grocery stores. Free sugars were manually differentiated from total sugars for each product. Products were classified according to two targeted consumer groups: children or general population.
Results: The nutrient profile of RTE breakfast cereals, granola bars and yoghurts and dairy desserts targeted to children differed from that of products intended at the general population. Child-targeted RTE breakfast cereals had the least favourable nutritional composition, with significantly higher content of carbohydrates, total sugars, free sugars and Na compared with breakfast cereals for the general population as well as child-targeted granola bars and yoghurts and dairy desserts. All child-targeted products analysed contained free sugars.
Conclusions: The current study supports the relevance to further regulate marketing to children on food product packages to ensure that such marketing is not present on food products with poor nutritional quality