362 research outputs found
The activation of modality in virtual objects assembly
International audienceManual assembly of virtual 3D objects is required in several application fields. We focus on tangible user interfaces which offer the opportunity to the user to perform virtual assemblies efficiently and easily. In each hand, the user manipulates a tracked prop, and the translations and rotations are directly mapped to the corresponding virtual object. However, with such interfaces, both hands are requisitioned, and the user cannot drop the props without changing the action or the expected results. We list and discuss the choice of four possible modalities to activate/deactivate the assembly modality: vocal modality, gestural modality, buttons, and foot pedals. We conclude that when using the foot pedals, the user's gesture is closer to the real-world behaviour
Adhesion and transcellular migration of neutrophils and B lymphocytes on fibroblasts
During tissue inflammation, infiltrated leukocytes may have physical contacts with fibroblasts. We observed that neutrophils and B lymphocytes adhered in a larger proportion than T cells on cultured fibroblasts. Microscopy showed that adhesion was also characterized by leukocyte engulfment by the fibroblasts. In migration assays, only neutrophils and B lymphocytes were selectively able to migrate through a fibroblast barrier. Adhesion and migration were increased by stimulation with tumor necrosis factor-alpha (TNF-alpha) and phorbol-12-myristate-13-acetate (PMA). Antibodies against ICAM-1/beta2 integrin blocked the interaction of neutrophils to fibroblasts. For B lymphocytes the couple VCAM-1/alpha4 integrin was also involved in this interaction. Human skin fibroblasts presented similar adhesion characteristics as rat cardiac fibroblasts. By measuring the distance between the border of migration holes and cadherin-positive adherens junctions, more than 65% of the holes correspond to the transcellular route over the paracellular route. Furthermore, vimentin staining revealed that the migration holes were highly nested by intermediate filaments in accordance with the transcellular route. Our results demonstrated that engulfment of neutrophils and B lymphocytes by fibroblasts resulted in selective passage by a transcellular route.This work was supported by grants from the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Counci
Carotenoids as biomarkers of fruit and vegetable intake in men and women
High fruit and vegetable (FAV) intake is associated with a lower prevalence of chronic diseases. Identifying the ideal number of FAV servings needed to reduce chronic disease risk is, however, difficult because of biases inherent to common self-report dietary assessment tools. The aim of our study was to examine the associations between daily FAV intake and plasma carotenoid concentrations in men and women enrolled in a series of fully controlled dietary interventions. We compiled and analysed data from a group of 155 men and 109 women who participated in six fully controlled dietary interventions and compared post-intervention fasting plasma carotenoid (a-carotene, ß-carotene, ß-cryptoxanthin, lutein, lycopene, zeaxanthin) concentrations with regard to the daily FAV servings consumed by the participants. We found that plasma ß-cryptoxanthin, lutein and zeaxanthin concentrations were positively associated with daily FAV servings (P=0·005). However, daily FAV intake was negatively associated with plasma a-carotene (P<0·0005) and lycopene (P<0·0001) concentrations, whereas no association was noted with plasma ß-carotene. When men and women were analysed separately, we found that for any given number of FAV servings consumed women had higher circulating lutein concentrations compared with men (P<0·01). Significant sex×FAV (P<0·0001) and sex×dietary ß-cryptoxanthin (P<0·0005) interactions were also noted favouring higher plasma ß-cryptoxanthin concentrations in women than in men for a given FAV consumption. Results from these fully controlled dietary feeding studies indicate that plasma ß-cryptoxanthin and lutein concentrations can be used as robust biomarkers of FAV consumption. They also suggest the existence of sex differences influencing circulating ß-cryptoxanthin and lutein concentrations following FAV consumption
Effect of an isoenergetic traditional Mediterranean diet on apolipoprotein A-I kinetic in men with metabolic syndrome
BACKGROUND: The impact of the Mediterranean diet (MedDiet) on high-density lipoprotein (HDL) kinetics has not been studied to date. The objective of this study was therefore to investigate the effect of the MedDiet in the absence of changes in body weight on apolipoprotein (apo) A-I kinetic in men with metabolic syndrome (MetS). METHODS: Twenty-six men with MetS (NCEP-ATP III) were recruited from the general community. In this fixed sequence study, participants’ diet was first standardized to a control diet reflecting current averages in macronutrient intake in North American men, with all foods and beverages provided under isoenergetic conditions for 5 weeks. Participants were then fed an isoenergetic MedDiet over a subsequent period of 5 weeks to maintain their weight constant. During the last week of each diet, participants received a single bolus dose of [5,5,5-(2)H(3)] (L)-leucine and fasting blood samples were collected at predetermined time points. ApoA-I kinetic was determined by multicompartmental modeling using isotopic enrichment data over time. Data were analyses using MIXED models. RESULTS: The response of HDL-cholesterol (C) to MedDiet was heterogeneous, such that there was no mean change compared with the control diet. Plasma apoA-I concentration (−3.9%) and pool size (−5.3%, both P < 0.05) were significantly lower after MedDiet and apoA-I production rate tended to be reduced (−5.7%, P = 0.07) with no change in apoA-I fractional catabolic rate (FCR, -1.6%, P = 0.64). Participants among whom HDL-C concentrations were increased with MedDiet (responders: mean ∆HDL-C: +9.9 ± 3.2%, N = 11) showed significantly greater reductions in apoA-I FCR and in apoB and very-low-density lipoprotein-triglycerides (VLDL-TG) concentrations (all P < 0.04) than those among whom HDL-C levels were reduced after the MedDiet (non-responders: mean ∆HDL-C: -12.0 ± 3.9%, N = 8). Correlation analysis revealed that only variations in apoA-I FCR (r = -0.48, P = 0.01) and in plasma VLDL-TG (r = −0.45, P = 0.03) concentrations were correlated with the individual HDL-C response to the MedDiet. CONCLUSIONS: Data from this controlled feeding study suggest that the heterogeneous response of HDL-C to MedDiet, in the absence of important weight loss, is primarily related to individual variations in apoA-I FCR and in plasma VLDL-TG concentrations. TRIAL REGISTRATION: ClinicalTrial.gov registration number: NCT0098865
The metabolic signature associated with the Western dietary pattern : a cross-sectional study
Background: Metabolic profiles have been shown to be associated to obesity status and insulin sensitivity. Dietary
intakes influence metabolic pathways and therefore, different dietary patterns may relate to modifications in metabolic
signatures. The objective was to verify associations between dietary patterns and metabolic profiles composed of amino
acids (AAs) and acylcarnitines (ACs).
Methods: 210 participants were recruited in the greater Quebec City area between September 2009 and December 2011.
Dietary patterns had been previously derived using principal component analysis (PCA). The Prudent dietary pattern was
characterised by higher intakes of vegetables, fruits, whole grain products, non-hydrogenated fat and lower intakes
of refined grain products, whereas the Western dietary pattern was associated with higher intakes of refined grain
products, desserts, sweets and processed meats. Targeted metabolites were quantified in 37 participants with the
Biocrates Absolute IDQ p150 (Biocrates Life Sciences AG, Austria) mass spectrometry method (including 14 amino
acids and 41 acylcarnitines).
Results: PCA analysis with metabolites including AAs and ACs revealed two main components explaining the most
variance in overall data (13.8%). PC1 was composed mostly of medium- to long-chain ACs (C16:2, C14:2, C14:2-OH,
C16, C14:1-OH, C14:1, C10:2, C5-DC/C6-OH, C12, C18:2, C10, C4:1-DC/C6, C8:1 and C2) whereas PC2 included certain
AAs and short-chain ACs (xLeu, Met, Arg, Phe, Pro, Orn, His, C0, C3, C4 and C5). The Western dietary pattern
correlated negatively with PC1 and positively with PC2 (r = −0.34, p = 0.05 and r = 0.38, p = 0.03, respectively),
independently of age, sex and BMI.
Conclusion: These findings suggest that the Western dietary pattern is associated with a specific metabolite
signature characterized by increased levels of AAs including branched-chain AAs (BCAAs) and short-chain ACs
An interaction effect between glucokinase gene variation and carbohydrate intakes modulates the plasma triglyceride response to a fish oil supplementation
A large inter-individual variability in the plasma triglyceride (TG) response to fish oil consumption has been observed. The objective was to investigate the gene-diet interaction effects between single-nucleotide polymorphisms (SNPs) within glucokinase (GCK) gene and dietary carbohydrate intakes (CHO) on the plasma TG response to a fish oil supplementation. Two hundred and eight participants were recruited in the greater Quebec City area. The participants completed a 6-week fish oil supplementation (5 g fish oil/day: 1.9-2.2 g EPA and 1.1 g DHA). Thirteen SNPs within GCK gene were genotyped using TAQMAN methodology. A gene-diet interaction effect on the plasma TG response was observed with rs741038 and CHO adjusted for age, sex and BMI (p = 0.008). In order to compare the plasma TG response between genotypes according to CHO, participants were divided according to median CHO. Homozygotes of the minor C allele of rs741038 with high CHO >48.59 % had a greater decrease in their plasma TG concentrations following the intake of fish oil (p < 0.05) than C/C homozygotes with low CHO and also than the other genotypes either with high or low CHO. The plasma TG response to a fish oil supplementation may be modulated by gene-diet interaction effects involving GCK gene and CHO
Plasma biomarkers of small intestine adaptations in obesity-related metabolic alterations
Background: Evidence suggests that pathophysiological conditions such as obesity and type 2 diabetes (T2D) are
associated with morphologic and metabolic alterations in the small intestinal mucosa. Exploring these alterations
generally requires invasive methods, limiting data acquisition to subjects with enteropathies or undergoing bariatric
surgery. We aimed to evaluate small intestine epithelial cell homeostasis in a cohort of men covering a wide range of
adiposity and glucose homoeostasis statuses.
Methods: Plasma levels of citrulline, a biomarker of enterocyte mass, and I-FABP, a biomarker of enterocyte death,
were measured by UHPLC‑MS and ELISA in 154 nondiabetic men and 67 men with a T2D diagnosis.
Results: Plasma citrulline was signifcantly reduced in men with insulin resistance and T2D compared to insulin sensi‑
tive men. Decreased citrulline levels were, however, not observed in men with uncontrolled metabolic parameters
during T2D. Plasma I-FABP was signifcantly higher in men with T2D, especially in presence of uncontrolled glycemic
and lipid profle parameters. Integration of both parameters, which estimate enterocyte turnover, was associated with
glucose homeostasis as well as with T2D diagnosis. Diferences in biomarkers levels were independent of age and BMI
and glucose fltration rates.
Conclusions: Our study supports a decreased functional enterocyte mass and an increased enterocyte death rate
in presence of metabolic alterations but emphasizes that epithelial cell homeostasis is especially altered in presence
of severe insulin resistance and T2D. The marked changes in small intestine cellularity observed in obesity and diabe‑
tes are thus suggested to be part of gut dysfunctions, mainly at an advanced stage of the disease
Effects of FADS and ELOVL polymorphisms on indexes of desaturase and elongase activities: results from a pre-post fish oil supplementation
Polymorphisms (SNPs) within the FADS gene
cluster and the ELOVL gene family are believed to influence
enzyme activities after an omega-3 (n-3) fatty acid (FA)
supplementation. The objectives of the study are to test
whether an n-3 supplementation is associated with indexes
of desaturase and elongase activities in addition to verify
whether SNPs in the FADS gene cluster and the ELOVL
gene family modulate enzyme activities of desaturases and
elongases. A total 208 subjects completed a 6-week supplementation period with 5 g/day of fish oil (1.9–2.2 g/day
of EPA ? 1.1 g/day of DHA). FA profiles of plasma
phospholipids were obtained by gas chromatography
(n = 210). Desaturase and elongase indexes were estimated
using product-to-precursor ratios. Twenty-eight SNPs from
FADS1, FADS2, FADS3, ELOVL2 and ELOVL5 were
genotyped using TaqMan technology. Desaturase indexes
were significantly different after the 6-week n-3 supplementation. The index of d-5 desaturase activity increased by
25.7 ± 28.8 % (p\0.0001), whereas the index of d-6
desaturase activity decreased by 17.7 ± 18.2 %
(p\0.0001) post-supplementation. Index of elongase
activity decreased by 39.5 ± 27.9 % (p\0.0001). Some
gene–diet interactions potentially modulating the enzyme
activities of desaturases and elongases involved in the FA
metabolism post-supplementation were found. SNPs within
the FADS gene cluster and the ELOVL gene family may
play an important role in the enzyme activity of desaturases
and elongases, suggesting that an n-3 FAs supplementation
may affect PUFA metabolism
Tangible Interaction in Mixed Reality Systems
chapitre 6, ISBN 978-1-84882-732-5In this chapter, we discuss the design of tangible interaction techniques for Mixed Reality environments. We begin by recalling some conceptual models of tangible interaction. Then, we propose an engineering-oriented software/hardware co-design process, based on our experience in developing tangible user interfaces. We present three different tangible user interfaces for real-world applications, and analyse the feedback from the user studies that we conducted. In summary, we conclude that, since tangible user interfaces are part of the real world and provide a seamless interaction with virtual words, they are well-adapted to mix together reality and virtuality. Hence, tangible interaction optimizes a users' virtual tasks, especially in manipulating and controlling 3D digital data in 3D space
Mineral density of hypomineralised and sound enamel
Molar Incisor Hypomineralisation (MIH) is a structural anomaly that affects the quality of tooth enamel and has important consequences for oral health. The developmentally hypomineralised enamel has normal thickness and can range in colour from white to yellow or brown. The purpose of the present study is to compare the mineral density of hypomineralised and normal enamel. The sample included eight MIH teeth from seven patients. MIH teeth were scanned using high resolution microtomography. Non-parametric statistical tests (Wilcoxon test for paired samples) were carried out. Hypomineralised enamel has decreased mineral density (mean 19%; p < 0.0001) compared to normal enamel. This weak enamel has implications in clinical management of MIH lesions
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