1,131 research outputs found

    Intra-session absolute and relative reliability of pressure pain thresholds in the low back region of vine-workers:effect of the number of trials

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    BACKGROUND: Pressure pain thresholds (PPT) are commonly used to quantify mechanical pain sensitivity of deep structures. Excellent PPT reliability has been previously reported among the low back of healthy subjects. However, there is a lack of studies assessing PPT over the low back of workers exposed to biomechanical risk factors of low back pain. Thus, the purpose of this study was threefold: (1) to evaluate the intra-session absolute and relative reliability as well as minimal detectable change (MDC) values of PPT within 14 locations covering the low back region of vine-workers and (2) to determine the number of trial required to ensure reliable PPT assessments and (3) to assess the effect of modifier factors such as gender, age, body mass index (BMI) and pain intensity on PPT reliability. METHODS: Twenty-nine vine-workers voluntarily participated in this study. Twenty-two reported low intensity of low-back pain while seven were pain-free. PPTs were assessed among 14 anatomical locations in the lower back region. Three trials were performed on each location with an interval time of at least one minute. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) for all possible combinations between trials. Bland-Altman plots were also generated to assess potential bias in the dataset. Finally, a repeated measure analysis of variance (RM-ANOVA) with the number of trials used as within subject factor was performed on (1) PPT, (2) ICC and (3) SEM values. RESULTS: ICC ranged from 0.86 to 0.99 for all anatomical locations and for all possible combinations between trials. SEM for comparison between trial 1–2, 2–3, 1–3 and, 1-2-3 ranged from respectively, 36.7–77.5, 27.8–77.7, 50–95.2 and, 39.3–80.8 kPa. ICC and SEM remained similar to the ones obtained for the entire population when taking modifier factors in consideration. The visual analysis of Bland-Altman plots suggested small measurement errors for all anatomical locations and for all possible combinations between trials. CONCLUSIONS: The assessment of PPTs of the lower back among vine-workers was found to have excellent relative and absolute reliability. Moreover, reliable measurements can be equally achieved when using the mean of three PPT measurement or with the first one

    Modular simulation and optimization of an 12MW industrial gasifier

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    In this work, a flexible model, built from elementary modules, is developed for an industrial waste gasification process, in an industrial moving bed reactor located in Morcenx (France). This gasifier is able to treat more than 46,875 ton/year of RDF (Refused Derived Fuel) waste for producing 12 MW. Drying, pyrolysis, combustion / gasification and plasma polishing are used to convert waste directly into a synthesis gas composed of carbon monoxide and hydrogen. This synthesis gas is then used for producing electricity via gas engine

    Local and Widespread Pressure Pain Hyperalgesia Is Not Side Specific in Females with Unilateral Neck Pain that Can Be Reproduced during Passive Neck Rotation

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    Current evidence for widespread hyperalgesia in non-specific neck pain (NSNP) is unclear. It is currently recommended to group NSNP patients according to pain-provoking movements. The aim of this study was to investigate local and widespread pain sensitivity in females with unilateral NSNP that is reproducible during passive neck rotation compared with matched controls, and to compare the side specific effect of pain location on pressure pain sensitivity among females with unilateral NSNP. Thirty-six females with unilateral NSNP evoked during passive ipsilateral (n = 20) or contralateral (n = 16) rotation toward the painful side were compared with 20 controls. Participants reported their pain intensity at rest and during passive neck rotation and completed the Neck Disability Index. Pressure pain thresholds (PPTs) were assessed bilaterally over the anterior scalene; the sternocleidomastoid; the levator scapulae; lateral to the spinous process of C6; the median, ulnar, and radial nerves; and the tibialis anterior. The ANOVA revealed lower PPTs in females with unilateral NSNP compared with the controls (all at p < 0.001), but no differences were found between the sides, nor was there any Groupside interaction. Among females with NSNP, those with higher pain intensity during ipsilateral rotation toward the painful side showed lower PPTs over the anterior scalene, median nerve, ulnar nerve, and tibialis anterior (all, p < 0.05) than females with higher pain intensity during contralateral rotation toward the painful side. These findings demonstrated bilateral local and widespread pressure pain hyperalgesia in females with unilateral NSNP that was reproducible during passive neck rotation compared with controls. There was no side specific effect of pain location on PPTs among females with unilateral NSNP.Ministerio de Educación, Cultura y Deporte (CAS 16/00046

    Prevalence of self-reported risk behaviors related to non-communicable diseases among Seychellois students aged 15 years and relationships with personal and other characteristics

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    [Table des matières] 1. Executive summary. 2. Methods. 3. Data collection phase and participation. 4. Tobacco. 4.1. Prevalence. 4.2. Reasons for smoking or for not smoking. 4.3. Comparison with other countries. 5. Drinking habits. 5.1. Prevalence. 5.2. Reasons for drinking or for not drinking. 5.3. Comparison with other countries. 6. Marijuana or hashish. 61. Prevalence. 6.2. Reasons for taking drugs and for not taking drugs. 6.3. Relationships between smoking, drinking and taking marijuana. 7. Physical activity outside school hours. 7.1. Prevalence. 7.2. Comparison with other countries. 7.3. Response to statements about sports. 8. Dietary habits. 8.1. Frequency of intake of selected foods. 8.2. Patterns for taking breakfast and lunch. 8.3. Comparison of food intake with other countries. 9. Body weight and perception of body image. 9.1. Prevalence overweight and obesity. 9.2. Self-perceived size, height appearance. 10. Practices during leisure time. 11. Indicators of personal skills and feelings. 12. Indicators of attitudes, behaviors and performance related to school. 13. Relationships between smoking, drug taking, drinking and overweight and selected personal, educational, emotional and other characteristics. 14. Information that students report to receive and wish to receive at school. Appendix: Questions (derived from the standard HBSC) and answers with detailed results by sex and class categories

    Increasing prevalence of overweight among Seychelles children, 1998-2002

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    To examine the prevalence and trends in excess weight among children in the Seychelles. Serial surveys of weight and height were conducted each year between 1998-2002 in all students attending four school grades (crèche, 4th, 7th and 10th years of compulsoryschool). Overweight and obesity were defined using age-specific body mass index (BMI) criteria of the International Obesity Task Force. Two questions explored physical activity at leisure time and daily walking time. From an eligible total of 32 077 observations between 1998-2002, data were available in 22 694 (71%), which corresponded to 17 627 separate children. Median age in the four grades was respectively 5.5, 9.2, 12.6, and 15.8 years. The overall prevalence of excess weight ('overweight' and 'obese' categories combined) was 10.5% in boys and 16.4% in girls. From 1998 to 2002, the prevalence of excess weight increased from 8.4% to 11.8% in boys and from 11.9% to 18.4% in girls. The increase of excess weight over calendar years was particularly marked among the younger children. Only a quarter of children reported walking at least 30 minutes per day. Leisure physical activity was inverselyassociated with excess body weight. The prevalence of excess body weight was high among school children of Seychelles and increased substantially over a five-year period. This calls for prompt and energetic policies and programs to promote physical activity and healthy nutrition among children. [Authors]]]> Obesity ; Child ; Adolescent ; Schools ; Seychelles oai:serval.unil.ch:BIB_F8F7E9DEAB96 2022-05-07T01:30:27Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_F8F7E9DEAB96 Recruitment of Matrix Metalloproteinase-9 (MMP-9) to the Fibroblast Cell Surface by Lysyl Hydroxylase 3 (LH3) Triggers Transforming Growth Factor-β (TGF-β) Activation and Fibroblast Differentiation. info:doi:10.1074/jbc.M114.622274 info:eu-repo/semantics/altIdentifier/doi/10.1074/jbc.M114.622274 info:eu-repo/semantics/altIdentifier/pmid/25825495 Dayer, C. Stamenkovic, I. info:eu-repo/semantics/article article 2015 Journal of Biological Chemistry, vol. 290, no. 22, pp. 13763-13778 info:eu-repo/semantics/altIdentifier/eissn/1083-351X urn:issn:0021-9258 <![CDATA[Solid tumor growth triggers a wound healing response. Similar to wound healing, fibroblasts in the tumor stroma differentiate into myofibroblasts (also referred to as cancer-associated fibroblasts) primarily, but not exclusively, in response to transforming growth factor-β (TGF-β). Myofibroblasts in turn enhance tumor progression by remodeling the stroma. Among proteases implicated in stroma remodeling, matrix metalloproteinases (MMPs), including MMP-9, play a prominent role. Recent evidence indicates that MMP-9 recruitment to the tumor cell surface enhances tumor growth and invasion. In the present work, we addressed the potential relevance of MMP-9 recruitment to and activity at the surface of fibroblasts. We show that recruitment of MMP-9 to the fibroblast cell surface occurs through its fibronectin-like (FN) domain and that the molecule responsible for the recruitment is lysyl hydroxylase 3 (LH3). Functional assays suggest that both pro- and active MMP-9 trigger α-smooth muscle actin expression in cultured fibroblasts, reflecting myofibroblast differentiation, possibly as a result of TGF-β activation. Moreover, the recombinant FN domain inhibited both MMP-9-induced TGF-β activation and α-smooth muscle actin expression by displacing MMP-9 from the fibroblast cell surface. Together our results uncover LH3 as a new docking receptor of MMP-9 on the fibroblast cell surface and demonstrate that the MMP-9 FN domain is essential for the interaction. They also show that the recombinant FN domain inhibits MMP-9-induced TGF-β activation and fibroblast differentiation, providing a potentially attractive therapeutic reagent toward attenuating tumor progression where MMP-9 activity is strongly implicated

    New events in stick slip oscillators behaviour

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    International audienceA two-degree-of-freedom oscillator excited by dry friction is considered. The system consists of two masses connected by a linear spring, one of which is connected to a fixed wall by another spring. The second mass is in contact with a driving belt moving at a constant velocity. Coulomb's friction force acts between the mass and the belt. Periodic orbits including stick phases and slip phases, during which the mass in contact with the belt moves faster than the belt, are found analytically. The stability of these "overshooting" orbits is also investigated

    Analytical investigation of periodic solutions for a coupled oscillator with dry friction

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    International audienceIn this paper, we present an analytical method to investigate the behavior of a two degrees of freedom oscillator excited by dry friction. The system consists of two masses connected by linear springs. These two masses are in contact with a driving belt moving at a constant velocity. The contact forces between the masses and the belt are obtained from Coulomb's friction laws. A set of periodic solutions involving a global sticking phase followed by several other phases where one or both masses are slipping, are found in close form. Stability conditions related to these solutions are obtained

    Two models of nonsmooth dynamical systems

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    International audienceTwo examples of nonsmooth systems are considered. The first one is a two degrees of freedom oscillator in the presence of a stop. A discontinuity appears when the system position reaches a critical value. The second example consists of coupled oscillators excited by dry friction. In this case, the discontinuity occurs when the system's velocities take a critical value. For both examples, the dynamical system can be partitioned into different configurations limited by a set of boundaries. Within each configuration, the dynamical model is linear and the close form solution is known. Periodic orbits, including several transitions between the various configurations of the system, are found in analytical form. The stability of these orbits is investigated by using the Poincaré map modeling

    New limit cycles of dry friction oscillators under harmonic load

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    International audienceWe consider a system composed of two masses connected by linear springs. One of the masses is in contact with a driving belt moving at a constant velocity. Friction force, with Coulomb's characteristics, acts between the mass and the belt. Moreover, the mass is also subjected to a harmonic external force. Several periodic orbits including stick phases and slip phases are obtained. In particular, the existence of periodic orbits including a part where the mass in contact with the belt moves in the same direction at a higher speed than the belt itself is proved. Non-sticking orbits are also found for a non-moving belt. We prove that this kind of solution is symmetric in space and in time

    Dynamics and Stability of a Two Degree of Freedom Oscillator With an Elastic Stop

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    International audienceA two-degree-of-freedom oscillator with a colliding component is considered. The aim of the study is to investigate the dynamic behavior of the system when the stiffness obstacle changes to a finite value to an infinite one. Several cases are considered. First, in the case of rigid impact and without external excitation, a family of periodic solutions are found in analytical form. In the case of soft impact, with a finite time duration of the shock, and no external excitation, the existence of periodic solutions, with an arbitrary value of the period, is proved. Periodic motions are also obtained when the system is submitted to harmonic excitation, in both cases of rigid or soft impact. The stability of these periodic motions is investigated for these four cases
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