Search results for "HTL"

Nordic adolescents responding to demanding survey scales in boring contexts: Examining straightlining

2022

Introduction Straightlining, or identical responses across all items within a multi-item scale, is often taken as an indication that responses to all items in a questionnaire are of poor quality. The purpose of this study was to examine straightlining on two scales: The Sense of Unity Scale (SUS) and the short version of the Warwick-Edinburgh Mental Well-being Scale (SWEMWBS). Methods Data stem from the 2017–2018 data collections in four Nordic countries of the Health Behaviour in School-children study (HBSC) (15-year-old students only; 50.9% girls; n = 5928). Data were weighted to adjust for oversampling of Swedish-speaking Finnish students and to equalize sample size across countries. The…

Arm end-point trajectories under normal and micro-gravity environments.

2001

Abstract The purpose of the present experiment was to study the way in which the CNS represents gravitational force during vertical arm pointing movements. Movements in upward and downward directions were executed by two cosmonauts in normal-gravity and weightlessness. Analyses focused upon finger kinematics in the sagittal plane. In normal-gravity, downward direction movements showed smaller curvatures and greater relative times to peak velocity ( AT MT ) when compared with upward direction movements. Data from the weightlessness experiments showed that whilst downward movements decreased their curvature during space flight, curvatures of upward movements changed slightly. Furthermore, AT …

Does the centre of mass remain stable during complex human postural equilibrium tasks in weightlessness?

2001

In normal gravity conditions the execution of voluntary movement involves the displacement of body segments as well as the maintenance of a stable reference value for equilibrium control. It has been suggested that centre of mass (CM) projection within the supporting base (BS) is the stabilised reference for voluntary action, and is conserved in weightlessness. The purpose of this study was to determine if the CM is stabilised during whole body reaching movements executed in weightlessness. The reaching task was conducted by two cosmonauts aboard the Russian orbital station MIR, during the Franco-Russian mission ALTAIR, 1993. Movements of reflective markers were recorded using a videocamera…

Comparison of actual and imagined execution of whole-body movements after a long exposure to microgravity

2003

Five cosmonauts were tested 30 days before a six-month space flight and also on the 2nd and the 6th day after their return to Earth. Cosmonauts performed and imagined a task that involved climbing two stairs to step onto a platform, jumping down with both feet and walking normally for a distance of 4 m. Durations of actual and imagined movements were measured by an electronic stopwatch. Results indicated that cosmonauts performed actual and imagined movements with similar durations before and after the space flight. However, the 2nd day after their return to Earth, cosmonauts significantly increased the durations of both actual and imagined movements. The durations of the imagined and actua…

''Active Collisions in Altered Gravity Reveal Eye-Hand Coordination Strategies''

2012

White, Olivier | Lefevre, Philippe | Wing, Alan M. | Bracewell, R. Martyn | Thonnard, Jean-Louis; International audience; ''Most object manipulation tasks involve a series of actions demarcated by mechanical contact events, and gaze is usually directed to the locations of these events as the task unfolds. Typically, gaze foveates the target 200 ms in advance of the contact. This strategy improves manual accuracy through visual feedback and the use of gaze-related signals to guide the hand/ object. Many studies have investigated eye-hand coordination in experimental and natural tasks; most of them highlighted a strong link between eye movements and hand or object kinematics. In this experime…

Antibodies anti HTLV-I/II in Sicilian residents, in drug addicts, and in African immigrants

1995

Green composites of organic materials and recycled post-consumer polyethylene

2004

International audience; Addition of organic fillers to post‐consumer recycled plastics can give rise to several advantages. First of all, the cost of these fillers is usually very low, the organic fillers are biodegradable contributing to an improved environmental impact and, last but not least, some mechanical and thermomechanical properties can be enhanced. Organic fillers are not widely used in the plastic industry although their use is increasing. Bad dispersion into the polymer matrix at high‐level content and poor adhesion with the matrix are the more important obstacles to this approach. In this work various organic fillers have been used with a post‐consumer plastic material origina…

2015

Previous studies have documented the detrimental effects of microgravity on human sensorimotor skills. While that work dealt with simple, laboratory-type skills, we now evaluate the effects of microgravity on a complex, realistic instrument-control skill. Twelve participants controlled a simulated power plant during the short-term microgravity intervals of parabolic flight as well as during level flight. To this end they watched multiple displays, made strategic decisions and used multiple actuators to maximize their virtual earnings from the power plant. We quantified control efficiency as the participants’ net earnings (revenue minus expenses), motor performance as hand kinematics and dyn…

Brief an Garlieb H. Merkel

1799

Ms. 930a, Nr. 8, Bl. 22r-23v Böttiger, Karl August. Brief an Garlieb H. Merkel, Weimar, d[en] 13. November 1797 Autora rokraksts / Autograph, vācu, angļu un latīņu val. / Deutsch, Englisch und Latein [4] lpp. / S. Attēlu numuri / Bildnummern: 930a-008-1 – 930a-008-4 Der Verfasser nennt in diesem inhaltsreichen Brief zahlreiche Namen und hält nicht nur die Verbindung mit Merkel, die aus dessen erstem Aufenthalt in Weimar resultierte, aufrecht, sondern gibt ihm weitere Hinweise und Empfehlung für seinen weiteren Aufenthalt in Dänemark. So rät er zur Übersetzung dreier Romane aus dem Englischen, darunter Jane Wests „A gossip's story“ (London 1796). Ferner bittet der Verfasser Merkel um Gefälli…

Λc± production in pp collisions with a new fragmentation function

2020

We study inclusive ${\mathrm{\ensuremath{\Lambda}}}_{c}^{\ifmmode\pm\else\textpm\fi{}}$-baryon production in $pp$ collisions in the general-mass variable-flavor-number scheme and compare with data from the LHCb, ALICE, and CMS collaborations. We perform a new fit of the $c\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ fragmentation function combining ${e}^{+}{e}^{\ensuremath{-}}$ data from OPAL and Belle. The agreement with LHC data is slightly worse compared with a calculation using an older fragmentation function, and the tension between different determinations of ${\mathrm{\ensuremath{\Lambda}}}_{c}^{\ifmmode\pm\else\textpm\fi{}}$ production cross sections from the LHC…