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The control of the body orientation and the center of mass position with respect to the feet was investigated under normo- and microgravity (space flight Altair), during erect posture and at the end of a forward or backward upper trunk movement. It was observed that during erect posture, the trunk orientation with respect to the vertical was inclined some 6 ° forward in both subjects under microgravity, whereas it was vertical or slightly backward oriented under normogravity. Under microgravity, on the contrary, the initial position CM changed either backwards or forwards. This result suggests that the inclined trunk posture might be due to misevaluating the vertically under microgravity and that different control mechanisms are involved in orienting the trunk and placing the CM. It was also noted that the final position of the CM at the end of the movement did not differ markedly between microgravity and normogravity. This result suggests that the kinematic synergies which stabilize the CM during uppertrunk movements may result from an automatic central control which is independent from the gravity constraints.

Without a means of studying large whales in a controlled experimental environment, less is understood about their sound production mechanisms than is understood about those of smaller odontocetes. To describe call production behavior in fin whales, we used a recent technique that correlates fast-sampling accelerometer signals from tags with concurrently recorded acoustic signals to identify calls produced by the tagged animal. We tagged 18 fin whales as part of the Southern California Behavioral Response Study (SOCAL BRS), of which four were confirmed to be calling. We were then able to describe their kinematic and social behavior in relation to call production. Behaviors associated with elevated call rates included shallow maximum dive depths, little body movement, and negative pitch in body orientation, similar to some other calling baleen whale species. These are the first descriptions of body orientation and dive depths at which fin whales are most likely to call. We also describe calling responses (or lack thereof) from blue and fin whales exposed to simulated mid-frequency active sonar. The call behavior characterizations presented here will help with predicting calling behavior from surface behavior, informing interpretation of passive acoustic data, and further investigating effects of anthropogenic sound on baleen whales.

Objective Turning around while stepping in place can be produced voluntarily. One way of producing involuntary turning around while stepping-in-place eyes closed is by training subjects onto a rotating platform while stepping-in-place and maintaining a fixed body orientation in space. This task produces a post-effect called “podokinetic after-rotation” (PKAR). Such training has been suggested for Parkinsonian patients. We tested the hypothesis that voluntary stepping-in-place and turning around also produces a post-effect similar to the PKAR. Material/patients and methods Sixteen subjects performed two different trials: 12 min of voluntary rotation around their vertical axes eyes closed and 12 min of stepping-in-place eyes open on the centre of a platform, rotating at of 60 °/s. Then, subjects were asked to continue stepping-in-place eyes closed for 10 min more. We recorded the body's segment positions. Subjects’ rotation velocity was the derivative of the angle described by the shoulders axis in the horizontal plane. Results The post-effect of stepping-in-place while voluntarily turning shares all features of the PKAR induced by the “podokinetic stimulation” of the platform rotation. In particular, stepping cadence, peak rotation velocity and its time decay are similar between the two conditions. Also, the ratio of the turning velocity pre (podokinetic stimulation or voluntary rotation) to the turning velocity of the PKAR is similar. Under both conditions, the post-rotation takes place without perception. Discussion-conclusion We suggest that the post-effect of both protocols is induced by the repeated voluntary contraction of the leg and foot intra-rotating pelvic muscles, which are active when the trunk rotates over the stance foot for aligning these segments, a synergy common to both protocols. We propose that stepping-in-place while voluntarily turning can substitute the rotating platform for learning the rotating coordination in patients with impairment of turning synergies of various origin. Source of funding This study was supported by the “Giovani Ricercatori 2009” grant (GR-2009-1471033) from the Italian Ministry of Health.

We examined the accuracy of stomach temperature archival units (STAUs), which are typically used to determine feeding activity in marine endotherms, with regard to determination of the time of prey ingestion as well as the number of prey items ingested and their masses. Units were deployed in nine species of free-living seabirds, where feeding conditions were uncontrolled, eight species of captive seabirds, where feeding conditions could be partially controlled, and in laboratory stomach simulations, where variables could be strictly controlled. The quality of data obtained on the timing of feeding, the mass ingested and the number of prey items ingested was subject to two main sources of error (i) those induced by changes in animal activity and (ii) those resulting from the physical form of the STAUs themselves. Animal activity factors considered important included the following: variability in (a) body temperature, (b) stomach blood perfusion, (c) consistency of stomach contents and (d) stomach churning and changes in body orientation. The physical form (size and buoyancy) of the STAU affected the location of the unit within the stomach, and thus the likelihood that ingested prey comes into contact with the sensor. The timing of prey ingestion can generally be determined accurately; however, considerable errors in mass estimates can occur if data acquired using STAUs are not critically assessed. An understanding of these sources of errors will allow researchers to construct STAUs appropriate to the species being studied and to analyze data critically so that errors are reduced.

GroupTogether is a system that explores cross-device interaction using two sociological constructs. First, F-formations concern the distance and relative body orientation among multiple users, which indicate when and how people position themselves as a group. Second, micro-mobility describes how people orient and tilt devices towards one another to promote fine-grained sharing during co-present collaboration. We sense these constructs using: (a) a pair of overhead Kinect depth cameras to sense small groups of people, (b) low-power 8GHz band radio modules to establish the identity, presence, and coarse-grained relative locations of devices, and (c) accelerometers to detect tilting of slate devices. The resulting system supports fluid, minimally disruptive techniques for co-located collaboration by leveraging the proxemics of people as well as the proxemics of devices.

Quadrupeds maintain the dorsal side up body orientation due to the activity of the postural control system driven by limb mechanoreceptors. Binaural galvanic vestibular stimulation (GVS) causes a lateral body sway toward the anode. Previously, we have shown that this new position is actively stabilized, suggesting that GVS changes a set point in the reflex mechanisms controlling body posture. The aim of the present study was to reveal the underlying neuronal mechanisms. Experiments were performed on decerebrate rabbits. The vertebral column was rigidly fixed, whereas hindlimbs were positioned on a platform. Periodic lateral tilts of the platform caused postural limb reflexes (PLRs): activation of extensors in the loaded and flexing limb and a decrease in extensor activity in the opposite (unloaded and extending) limb. Putative spinal interneurons were recorded in segments L4–L5 during PLRs, with and without GVS. We have found that GVS enhanced PLRs on the cathode side and reduced them on the anode side. This asymmetry in PLRs can account for changes in the stabilized body orientation observed in normal rabbits subjected to continuous GVS. Responses to platform tilts (frequency modulation) were observed in 106 spinal neurons, suggesting that they can contribute to PLR generation. Two neuron groups were active in opposite phases of the tilt cycle of the ipsi-limb: F-neurons in the flexion phase, and E-neurons in the extension phase. Neurons were driven mainly by afferent input from the ipsi-limb. If one supposes that F- and E-neurons contribute, respectively, to excitation and inhibition of extensor motoneurons, one can expect that the pattern of response to GVS in F-neurons will be similar to that in extensor muscles, whereas E-neurons will have an opposite pattern. We have found that ∼40% of all modulated neurons meet this condition, suggesting that they contribute to the generation of PLRs and to the GVS-caused changes in PLRs.

International audience; It is established that the body position influences verticality perception. In contrast, the possible influence of the awareness of the body orientation on verticality perception has never been investigated. This hypothesis, explored in the present study, is supported by the role played by the parietal cortex and the insula in both body position awareness and verticality perception. Nine subjects were asked to estimate the direction of the visual vertical (VV) by 12 adjustments of a luminous line in three conditions: (1) a control condition (subjects were upright and aware of their position), (2) a condition of congruence between the lateral body tilt and the awareness of this tilt, and (3) a condition of dissociation of subjective and objective orientations (tilted subjects who felt upright). The dissociation between objective and subjective orientations was obtained by inducing experimentally a postural vertical (PV) bias through 5 min of lateral body tilt at 30° in darkness in a motorized flight simulator (mean 8.8° ± 4; min 6.2°; max 17.4°). VV orientation and variability were measured (expressed below in this order). As compared to the upright condition (0.3° ± 0.2; 0.8° ± 0.5), subjects showed similar VV orientation (0.1° ± 0.6; p=0.82) but an increased variability (1.4°±0.5; p

Summary Recent studies have evoked heated debate about whether biologically generated (or biogenic) fluid disturbances affect mixing in the ocean. Estimates of biogenic inputs have shown that their contribution to ocean mixing is of the same order as winds and tides. Although these estimates are intriguing, further study using theoretical, numerical and experimental techniques is required to obtain conclusive evidence of biogenic mixing in the ocean. Biogenic ocean mixing is a complex problem that requires detailed understanding of: (1) marine organism behavior and characteristics (i.e. swimming dynamics, abundance and migratory behavior), (2) mechanisms utilized by swimming animals that have the ability to mix stratified fluids (i.e. turbulence and fluid drift) and (3) knowledge of the physical environment to isolate contributions of marine organisms from other sources of mixing. In addition to summarizing prior work addressing the points above, observations on the effect of animal swimming mode and body morphology on biogenic fluid transport will also be presented. It is argued that to inform the debate on whether biogenic mixing can contribute to ocean mixing, our studies should focus on diel vertical migrators that traverse stratified waters of the upper pycnocline. Based on our understanding of mixing mechanisms, body morphologies, swimming modes and body orientation, combined with our knowledge of vertically migrating populations of animals, it is likely that copepods, krill and some species of gelatinous zooplankton and fish have the potential to be strong sources of biogenic mixing.

Generalization of the dynamic clamp concept in neurophysiology and behavior. Chamorro et al. PLoS ONE. 2012. 7(7) doi: 10.1371/journal.pone.0040887, The idea of closed-loop interaction in in vitro and in vivo electrophysiology has been successfully implemented in the dynamic clamp concept strongly impacting the research of membrane and synaptic properties of neurons. In this paper we show that this concept can be easily generalized to build other kinds of closed-loop protocols beyond (or in addition to) electrical stimulation and recording in neurophysiology and behavioral studies for neuroethology. In particular, we illustrate three different examples of goal-driven real-time closed-loop interactions with drug microinjectors, mechanical devices and video event driven stimulation. Modern activity-dependent stimulation protocols can be used to reveal dynamics (otherwise hidden under traditional stimulation techniques), achieve control of natural and pathological states, induce learning, bridge between disparate levels of analysis and for a further automation of experiments. We argue that closed-loop interaction calls for novel real time analysis, prediction and control tools and a new perspective for designing stimulus-response experiments, which can have a large impact in neuroscience research., This work was supported by Spanish MICINN (Ministerio de Ciencia e Innovacion) BFU2009-08473 and TIN-2010-19607.

Estimation of human body orientation is an important cue to study and understand human behaviour, for different tasks such as video surveillance or human-robot interaction. In this paper, we propose an approach to simultaneously estimate the body orientation of multiple people in multi-view scenarios, which combines a 3D human body shape and appearance model with a 2D template matching approach. In particular, the 3D model is composed of a generic shape made up of elliptic cylinders, and a 3D colored point cloud (appearance model), obtained by back-projecting pixels from foreground images onto the geometric surfaces. In order to match the reconstructed appearance to target images in arbitrary poses, the appearance is re-projected onto each of the different views, by generating multiple templates that are pixel-wise, robustly matched to the respective foreground images. The effectiveness of the proposed approach is demonstrated through experiments in indoor sequences with manually-labeled ground truth, using a calibrated multi-camera setup.

The purpose of the study was to examine the effect of body orientation with respect to gravity on infant's reaching quantity and quality. Two groups, 12- to 19-week-old and 20- to 27-week-old infants, were seated in three positions: vertical (90 degrees from horizontal), recline (60 degrees), and supine (0 degrees). Nine balls on a black board were presented. Video recordings were used to measure quantity of reaching (number and duration of reaches) and quality of reaching (open or closed hand, starting position of the arm, and position of touched and grasped balls). On the quantity measure there was a significant age x body position interaction that indicated that the 12- to 19-week-olds showed reaching behavior in the vertical position equal to that of 20- to 27-week-old infants in all positions. A similar tendency, although not significant, was found for the quality measurements. These findings indicate that the development of reaching does not just reflect maturation of the central nervous system, but a changing interaction between organismic and environmental constraints.

Abstract. The mechanism of aggregation behaviour of sticklebacks, Gasterosteus aculeatus , in response to fright stimuli simulating an aerial predator was investigated. The results provide evidence for the hypothesis that during aggregation individual fish minimize the approach time to a conspecific (time minimization hypothesis). The first experiment investigated how the approach time depends on the body orientation of a fish and on the initial distance to a conspecific. These data were interpolated and used in experiment 2 to predict the approach behaviour of individual fish in particular model constellations involving three fish whose positions were controlled with the help of glass cylinders. In the final experiment, the hypothesis of time minimization was tested on freely aggregating shoals. Fish at the shoal periphery started the aggregation process significantly earlier than central conspecifics and over 95% of the focal fish approached their nearest neighbour in time as predicted by the model.

Turning is crucial for animals, particularly during predator–prey interactions and to avoid obstacles. For flying animals, turning consists of changes in ( i ) flight trajectory, or path of travel, and ( ii ) body orientation, or 3D angular position. Changes in flight trajectory can only be achieved by modulating aerodynamic forces relative to gravity. How birds coordinate aerodynamic force production relative to changes in body orientation during turns is key to understanding the control strategies used in avian maneuvering flight. We hypothesized that pigeons produce aerodynamic forces in a uniform direction relative to their bodies, requiring changes in body orientation to redirect those forces to turn. Using detailed 3D kinematics and body mass distributions, we examined net aerodynamic forces and body orientations in slowly flying pigeons ( Columba livia ) executing level 90° turns. The net aerodynamic force averaged over the downstroke was maintained in a fixed direction relative to the body throughout the turn, even though the body orientation of the birds varied substantially. Early in the turn, changes in body orientation primarily redirected the downstroke aerodynamic force, affecting the bird’s flight trajectory. Subsequently, the pigeon mainly reacquired the body orientation used in forward flight without affecting its flight trajectory. Surprisingly, the pigeon’s upstroke generated aerodynamic forces that were approximately 50% of those generated during the downstroke, nearly matching the relative upstroke forces produced by hummingbirds. Thus, pigeons achieve low speed turns much like helicopters, by using whole-body rotations to alter the direction of aerodynamic force production to change their flight trajectory.

The postural system maintains a specific body orientation and equilibrium during standing and during locomotion in the presence of many destabilizing factors (external and internal). Numerous studies in humans have revealed essential features of the functional organization of this system. Recent studies on different animal models have significantly supplemented human studies. They have greatly expanded our knowledge of how the control system operates, how the postural functions are distributed within different parts of CNS, and how these parts interact with each other to produce postural corrections and adjustments. This review outlines recent advances in the studies of postural control in quadrupeds, with special attention given the neuronal postural mechanisms.

Falls are dangerous for the aged population as they result in serious detrimental consequences. Therefore, many fall detection methods have been proposed. Most of these methods characterize falls by large accelerations and fast body orientation changes. However, certain activities like sitting down quickly, vigorous gaits, and jumping, also show these characteristics, and thus are hard to distinguish from real falls. Moreover, many falls in the elderly are slow falls which show lower activity levels. Existing work fails to detect slow falls effectively because they only identify falls with high activity levels.In this paper, we present a grammar-based fall detection framework which not only better distinguishes fall-like activities from real falls, but also emphasizes the detection of slow falls. We utilize posture information extracted from on-body sensors and context information collected from sensors deployed in the house to reduce false positives. A fall in our framework is detected as a sequence of sensor events. We provide a context-free grammar to define these sequences so that the framework can be easily extended to detect more kinds of falls. Our case study shows that our method can distinguish various fall-like activities from real falls and can also effectively detect both fast falls and slow falls. The integration evaluation shows that our method achieves both high sensitivity and high specificity.

Elephant seals are one of the most proficient diving mammals in the world and are also one of the most studied. However, their long periods at sea and pelagic habits make research into their foraging ecology particularly challenging. Most current understanding comes from the use of time-depth recorders (TDRs). We used TDRs that additionally recorded body pitch and roll on four juvenile southern elephant seals (Mirounga leonina) foraging over the Patagonian Shelf to describe their diving behaviour and compared them with those of adults, using standard descriptions of elephant seal dive profile types provided by the literature. Over 280 days of diving data showed that dive types were similar to those of adults (types: A, B, C, D, Eb and Ef) but that dive types A and C differed slightly, probably because our animals were constrained by bottom topography. Steep dive and return-to-surface angles in all dive types except type B indicate that animals generally attempt to maximize vertical displacement. Horizontal displacement was much greater in type B dives, which indicates a travelling function. Pitching and rolling behaviour lends support to the functions ascribed to the dive types already described for adult elephant seals, although type Eb dives are unusual in that the animals appear to be taking prey by up-ending in the benthos. Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Wilson, Rory P.. Swansea University; Reino Unido Fil: Dignani, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Lewis, Mirtha Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Campagna, Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos

In the present study, we quantitatively described and compared lower extremity neuromuscular patterns during level cycling (LC), 10 and 20% uphill cycling (UC). We hypothesized that both the timing and intensity of activity of selected lower extremity muscles will differ between steep (but not moderate slope) UC condition and LC. Twelve trained mountain bikers performed an experimental test with three different cycling conditions (level, 10% slope and 20% slope) with EMG monitoring of eight lower extremity muscles. Significant changes (p < 0.05) in muscle activation timing during 20% UC compared to LC (15° later onset and 39° earlier offset) were observed in m. rectus femoris (RF). Range of activity during 20% UC compared to LC was also significantly (p < 0.05) modified in m. vastus medialis, m. vastus lateralis (8° and 5° shorter) and m. biceps femoris (BF ; 17° longer). Furthermore, a reduction of EMG activity level was observed for RF and m. tibialis anterior (TA) during 20% UC compared to LC (25 and 19% ; p < 0.05), while the opposite effect was observed for m. gluteus maximus (GM ; 12% ; p < 0.05). Peak cross-correlation coefficients in all cycling conditions for all muscles were high (all coefficients ≥0.83). We have shown that altered body orientation during steep, but not moderate, slope UC significantly modified the timing and intensity of several lower extremity muscles, the most affected being those that cross the hip joint and TA. The observed modifications in neuromuscular patterns during 20% UC could have a significant effect on lower extremity joint kinetics and cycling efficiency.

Vibrio alginolyticus is a marine bacterium with a single polar flagellum when growing in low viscous liquid media. Recently, we found that they carry out a novel cyclic 3-step motility pattern. In one cycle they swim forward, backward and at the end of the backward swimming they are able to use their flagellum to flick and actively change their cell body orientation. To understand how this novel motility pattern is regulated by V. alginolyticus, we studied their chemotactic response to a sudden increase of the attractant serine concentration. We made use of caged serine, which can be released by UV light in a fraction of second to achieve a sudden change in the serine concentration. We compared their swimming behavior before and after the UV flash. We found that in short time, they treat forward and backward swimming equally, i.e. they extend their current swimming interval regardless of the swimming direction. However, in a long time but before adaptation, cells become gradually forwardly biased. This chemotactic strategy enables the bacteria to swim up the attractant gradient quickly as well as to localize around the top of the gradient to get a maximum nutrient exposure. This perhaps is important in an ocean environment where nutrient are distributed intermittently in space and time.

Lectures are often conceptualized in terms of information transfer. Science and mathematics professors tend to talk about using lectures to “get information across” and about how much their students do or do not “get” the main points of a lecture.

PVAT (Posture Video Analysis Tool) has been developed to meet the special needs of ergonomist and human factors analyst attempting to evaluate microgravity working posture from video footage. These specialists often have very little or no control over the video coverage. Moreover, the majority of Shuttle mission videos are not recorded for quantitative analysis. The purpose for developing PVAT is to provide a structured methodology in which these specialists could optimize the data collection technique. PVAT is specifically designed to document microgravity postures using videos of astronauts working in a space environment. The primary focus of PVAT is identifying the microgravity working postures and relating them to design issues in the workplace. This tool is currently an interactive software prototype written in SupercardTM. Users are provided with a set of input parameters such as: subject code, body orientation, targeted body part, camera view (given subject location), body movement, and rating level. A secondary set of inputs are also available which provides the ability to document extraneous behaviors or activities such as bending, reaching and interruptions. The tool allows for the input parameters to be customized as needed. Once the setup is defined, the user begins documenting the target posture and/or behaviors. The paper will discuss PVAT, its space applications and plans for its use.

The type II microtrich sensilla on the lotic amphipod Gammarus pseudolimnaeus Bousfield enable it to control body orientation while swimming, as animals with their sensilla masked spent significantly more time swimming on their sides. These sensilla appear to be involved in the behavioural process that allows the animal to orient into the current (positive rheotaxis), as significantly fewer masked animals were able to turn into novel current flows compared with controls. The sensilla do not appear to play a role in detecting gravity. Results suggest that the sensilla transmit hydromechanical sensory information to the animal, and it is thought that the individual sensilla act in unison as a kinetic sensory organ. The sensilla are well adapted for such a hydromechanical role, as they would likely only be stimulated by currents hitting them broadside on. The sensilla are grouped, with each sensillum facing in a different direction, and the groups are located at appropriate positions for detecting current flows. The sensilla do not play a role in the detection of vibrations. Nor do they play a chemosensory role in the detection of food or predators; however, a role in conspecific chemodetection cannot be ruled out.

International audience; We studied the effect of static pitch body tilts on the perception of self-motion direction induced by a visual stimulus. Subjects were seated in front of a screen on which was projected a 3D cluster of moving dots visually simulating a forward motion of the observer with upward or downward directional biases (relative to a true earth horizontal direction). The subjects were tilted at various angles relative to gravity and were asked to estimate the direction of the perceived motion (nose-up, as during take-off or nose-down, as during landing). The data showed that body orientation proportionally affected the amount of error in the reported perceived direction (by 40% of body tilt magnitude in a range of +/- 20 degrees) and these errors were systematically recorded in the direction of body tilt. As a consequence, a same visual stimulus was differently interpreted depending on body orientation. While the subjects were required to perform the task in a geocentric reference frame (i.e., relative to a gravity-related direction), they were obviously influenced by egocentric references. These results suggest that the perception of self-motion is not elaborated within an exclusive reference frame (either egocentric or geocentric) but rather results from the combined influence of both. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

The role of body orientation in the orienting and allocation of social attention was examined using an adapted Simon paradigm. Participants categorized the facial expression of forward facing, computer-generated human figures by pressing one of two response keys, each located left or right of the observers' body midline, while the orientation of the stimulus figure's body (trunk, arms, and legs), which was the task-irrelevant feature of interest, was manipulated (oriented toward the left or right visual hemifield) with respect to the spatial location of the required response. We found that when the orientation of the body was compatible with the required response location, responses were slower relative to when body orientation was incompatible with the response location. In line with a model put forward by Hietanen (1999), this reverse compatibility effect suggests that body orientation is automatically processed into a directional spatial code, but that this code is based on an integration of head and body orientation within an allocentric-based frame of reference. Moreover, we argue that this code may be derived from the motion information implied in the image of a figure when head and body orientation are incongruent. Our results have implications for understanding the nature of the information that affects the allocation of attention for social orienting. ispartof: FRONTIERS IN INTEGRATIVE NEUROSCIENCE vol:6 issue:JANUARY 2012 ispartof: location:Switzerland nrpages: 28 status: published

International audience; Changing direction suddenly requires a whole body reorientation strategy. In sporting duels such as an attacker versus a defender in rugby, successful body orientation/reorientation strategies are key to successful performance. The aim of this study is to see which biomechanical factors, whilst taking into account biomechanical constraints, are used by an attacker in a 1 vs. 1 duel in rugby. More specifically we wanted to see how an attacker tries to deceive the defender yet disguise his intentions by comparing effective deceptive movements (DM+), ineffective deceptive movements (DM-) and non-deceptive movements (NDM). Eight French amateur expert rugby union players were asked to perform DMs and NDMs in a real 1 vs. 1 duel. For each type of movement (DM+, DM-, NDM) different relevant orientation/reorientation parameters, medio-lateral displacement of the centre of mass (COM), foot, head, upper trunk and lower trunk yaw; and upper trunk roll were analysed and compared. Results showed that COM displacement and lower trunk yaw were minimised during DMs whilst foot displacement along with head and upper trunk yaw were exaggerated during DMs (DM+ and DM-). This would suggest that the player is using exaggerated body-related information to consciously deceive the defender into thinking he will run in a given direction whilst minimising other postural control parameters to disguise a sudden change in posture necessary to modify final running direction. Further analysis of the efficacy of deceptive movements showed how the disguise and deceit strategies needed to be carefully balanced to successfully fool the defender.

The vertical distribution, body orientation and mobility of pike free embryos were studied at 10 °C in 25-cm individual water columns. Five steps were identified: (1) a resting phase, up to day (D) 4 post-hatching; (2) an ascent phase (D1–D4); (3) a plateau (D5–D8), characterized by a wall-attachment behaviour in the subsurface zone; (4) a break-off phase (D9–D13); and (5) a final localization between mid-water and surface, corresponding to the air filling of the swim bladder and to the transition to active, horizontal swimming (D14–D17). Free embryos could be: side-lying (phase 1, late phase 4 and phase 5); lying upright (phases 4 and 5); vertically suspended with adhesion to the wall (phases 2–3 and early phase 4); and in oblique or horizontal position (phase 5). The opening of mouth and anus occurred during phases 2 and 3 and swim bladder filling started on days 13–14. Free embryo mobility was low and stable during the first 5 days and increased regularly thereafter to reach maximal levels on days 14–16. This research provides evidence for a more complex and more variable temporal pattern of free embryo vertical distribution, posture and mobility than previously thought. The vertical distribution, body orientation and mobility of pike free embryos were studied at 10 °C in 25-cm individual water columns. Five steps were identified: (1) a resting phase, up to day (D) 4 post-hatching; (2) an ascent phase (D1–D4); (3) a plateau (D5–D8), characterized by a wall-attachment behaviour in the subsurface zone; (4) a break-off phase (D9–D13); and (5) a final localization between mid-water and surface, corresponding to the air filling of the swim bladder and to the transition to active, horizontal swimming (D14–D17). Free embryos could be: side-lying (phase 1, late phase 4 and phase 5); lying upright (phases 4 and 5); vertically suspended with adhesion to the wall (phases 2–3 and early phase 4); and in oblique or horizontal position (phase 5). The opening of mouth and anus occurred during phases 2 and 3 and swim bladder filling started on days 13–14. Free embryo mobility was low and stable during the first 5 days and increased regularly thereafter to reach maximal levels on days 14–16. This research provides evidence for a more complex and more variable temporal pattern of free embryo vertical distribution, posture and mobility than previously thought., La répartition verticale, l’orientation corporelle et la mobilité de l’embryon libre de brochet ont été étudiées dans des colonnes d’eau individuelles de 25 cm à 10 °C. Cinq étapes ont été identifiées : (1) une phase de repos, pouvant durer jusqu’à 4 jours (J) après éclosion; (2) une phase ascensionnelle (J1–J4); (3) un plateau (J5–J8) caractérisé par un comportement d’adhésion à la paroi en subsurface; (4) une phase de rupture (J9–J13); et (5) une localisation finale entre la mi-profondeur et la surface, correspondant au remplissage de la vessie natatoire et au passage à une nage active dans le plan horizontal (J14–J17). Les orientations corporelles suivantes ont été observées : position allongée sur le flanc (phase 1, fin de phase 4, phase 5); position allongée sur l’abdomen (phases 4 et 5); suspension verticale avec adhésion aux parois (phases 2–3 et début de phase 4); et position oblique ou horizontale (phase 5). L’ouverture de la bouche puis de l’anus est intervenue au cours des phases 2 et 3 et le remplissage de la vessie natatoire a débuté à J13 ou J14. Le degré de mobilité de l’embryon libre, peu élevé et stable au cours des 5 premiers jours, a ensuite augmenté de façon régulière pour atteindre les valeurs les plus élevées entre J14 et J16. La présente étude met en évidence pour la répartition spatiale, la posture et la mobilité de l’embryon libre l’existence d’une séquence temporelle plus complexe et plus variable que ne le suggéraient les connaissances antérieures.

When observed from a submersible, the mesopelagic paralepidid Notolepis rissoi (Pisces: Paralepididae) will hover head up with the body at about 45°. The fish's swimming motion is restricted to the extreme caudal region with most of the body rigid. The trunk lateral-line canal ends at about the position that caudal motion becomes noticeable and there is a great decrease in neuromast size near the posterior end of the canal. The size of the neuromasts is also inversely related to the percentage of red muscle at the same body level. The eyes have an aphakic space oriented dorso-anteriorly at about 45° to the body axis so that during hovering the aphakic space is oriented vertically. Retinal anatomy indicates that photoreceptors opposite the aphakic space appear to enhance resolution at the cost of sensitivity, whilst lateral photoreceptors enhance sensitivity at the expense of resolution. We interpret the swimming attitude and mechanics as adaptations to minimize self-induced oscillations which would be deleterious to visual and lateral-line function.

Ondersoek is ingestel na die liggaamsorientasie van die blesbok Damaliscus dorcas phillipsi ten opsigte van sonshoek en windrigting in ’n skadulose omgewing in die sentrale Oranje-Vrystaat. Gedurende die vroeë oggend en laat middag wanneer die sonshoogte en omgewingstemperatuur relatief laag is, oriënteer die bokke klaarblyklik lateraal ten opsigte van die son. Namate die temperatuur gedurende die middel van die dag toeneem, toon die bokke ’n neiging om in lyn met die inkomende sonstrale, maar lateraal ten opsigte van die windrigting, te oriënteer

Summary The body orientation of black wildebeest Connochaetes gnou in relation to the angle of the sun and direction of the wind was investigated during the cold and hot seasons in the central Orange Free State. Results indicate that the wildebeest orientate laterally during the early morning and late afternoon when the sun's altitude and ambient temperatures are relatively low. As the temperature and wind speed increased during midday, body position was increasingly influenced by wind. Lying down for extended periods during the hottest time of the day probably reduced the intake of reflected radiation from the ground. Resume On a observe l'orientation du corps des gnous a queue blanche, Connochaetes gnou, en relation avec l'angle d'incidence du soleil et la direction du vent, pendant les saisons froides et chaudes, dans l'Etat Libre d'Orange. Les resultats montrent que les gnous se presentent lateralement au soleil du matin et de la fin de l'apres midi, quand le soleil et la temperature ambiante sont relativement bas. Quand la temperature et la vitesse du vent augmentent au milieu du jour, la position du corps est de plus en plus influencee par le vent. Le fait de se coucher pendant de longues periodes au moment le plus chaud de la journee reduit probablement la reflexion de la chaleur venant du sol.

We tested 3D spatial memory for 59 college students in a 50-cm x 50-cm x 50-cm cube. An aperture in the center of each of the cube's six surfaces revealed a picture on a computer monitor. The pictures' locations and orientations changed to simulate multiple perspectives. A pre-trial icon indicated the simulated body orientation, entrance hatch (the picture behind the head), and the target. A trial began with no pictures, and the trainee pressed a key to indicate the target's remembered position. A trail concluded with pictures, and the trainee pressed a key to indicate the target's actual position. Visual orientation illusions suggested that supine trainees should perform better. Memory errors did not support this prediction. Groups who started erect and switch to supine were similar to groups that did the opposite, except for the first 12 trials in which the Erect-Supine Group was better.

International audience; We examined to which extent proprioceptive information involved in the perception of subjective vertical corresponded to mechanical mass-based axes of the body. Blindfolded subjects (n=14) estimated their subjective vertical in conditions of deviation of the centre of mass (CM) of (1) the head-trunk unit or (2) the head segment alone. Verticality estimates (provided in a haptic modality) were significantly altered by the deviation of the head-trunk CM (by either 4 degrees or 7 degrees), indicating that the subjects used mass-based proprioceptive information stemming from the trunk. Modifying the perception of body orientation by shifting the trunk CM sideways while keeping the body vertical, deviates the subjective vertical towards the opposite side in a similar way to the so-called 'E-effect'. The induced deviations of head CM (9.33 degrees) did not affect the subjective vertical, suggesting that when the balance of the body is not threatened, proprioceptive or vestibular information is prioritized to estimate gravitational direction.

Whether the vertical body orientation depends on the initial posture and/or the type of straightening up movement is the main question raised in this paper. Another objective was to specify the compensatory role of visual input while adopting an erected posture during microgravity. The final body orientation was analysed in microgravity during parabolic flights. After either (1) straightening up movement from a crouching or (2) a sitting posture, with and without vision. The main results are the following: (1) a vertical erected final posture is correctly achieved after sit to stand movement, whereas all subjects were tilted forward after straightening up from a crouching posture and (2) vision may contribute to correct final posture. These results suggest the existence of a re-weighting of the remaining sensory information, visual information, contact cutaneous cues and proprioceptive information under microgravity condition. We can put forward the alternative hypothesis that the control of body orientation under microgravity condition may also be achieved on the basis of a postural body scheme, that seems to be dependant on the type of movement and/ or the initial position of the whole body.

Falls in elderly people have been recognized as a major health problem in aging population. This paper describes the development of an accurate, accelerometer based fall detector capable of locating the wearer and sending alarm short messages (SMS). The device worn on the waist uses a two-stage fall detection algorithm, which senses rapid impact and body orientation of the wearer. To evaluate the device and the algorithm, an experiment on 5 subjects was conducted. The device is especially adapted to safely and accurately monitor elderly people without influencing their privacy and comfort. It is hoped that such a device will promote an integrated approach to the management of falls of elderly in the community.

The current pilot study aimed at providing an initial assessment of how anxiety influences police officers' shooting behavior. Seven police officers participated and completed an identical shooting exercise under two experimental conditions: low anxiety, against a non-threatening opponent, and high anxiety (HA), against a threatening opponent who occasionally shot back using colored soap cartridges. Measurements included shooting accuracy, movement times, head/body orientation, and blink behavior. Results showed that under HA, shooting accuracy decreased. Underlying this degradation of performance, participants acted faster and made themselves smaller to reduce the chance of being hit. Furthermore, they blinked more often, leading to increases in the amount of time participants had their eyes closed. Findings provide support for attentional control theory, hereby also pointing to possible interventions to improve police officers' shooting performance under pressure. © 2010 Taylor & Francis.

"Pusher syndrome" is classically described as a disorder of body orientation in the coronal plane. Although it mainly occurs in stroke patients, non-stroke causes have been described. Pusher behaviour is characterized by a tilt towards the contralesional paretic side and a resistance to external attempts to rectify. It may occur with or without hemispatial neglect, which in itself may be the cause of a usually ipsilesional shift of attention and body orientation in the axial plane. In this report we describe two patients with a marked disturbance of body orientation in the sagittal plane with imbalance, posterior tilt and an active resistance to forward pulling or pushing. By analogy we propose the term "posterior pusher" syndrome for the clinical picture.

Resting and grazing cattle and deer tend to align their body axes in the geomagnetic North-South direction. The mechanism(s) that underlie this behavior remain unknown. Here, we show that extremely low-frequency magnetic fields (ELFMFs) generated by high-voltage power lines disrupt alignment of the bodies of these animals with the geomagnetic field. Body orientation of cattle and roe deer was random on pastures under or near power lines. Moreover, cattle exposed to various magnetic fields directly beneath or in the vicinity of power lines trending in various magnetic directions exhibited distinct patterns of alignment. The disturbing effect of the ELFMFs on body alignment diminished with the distance from conductors. These findings constitute evidence for magnetic sensation in large mammals as well as evidence of an overt behavioral reaction to weak ELFMFs in vertebrates. The demonstrated reaction to weak ELFMFs implies effects at the cellular and molecular levels.

This paper presents a quaternion-based Gauss-Newton optimizer for tracking human body orientation using inertial/magnetic sensors. Since a computationally efficient and robust algorithm for estimating orientation is critical for low-cost and real-time ambulatory purposes, the optimizer is formulated using a virtual rotation concept in order to decrease the computing time. In addition, to guard against the effects of fast body motions and temporary ferromagnetic disturbances, a situational measurement vector selection procedure is adopted in conjunction with the Gauss-Newton optimizer.

International audience; Seven female elite gymnasts performed backward giant circles on the high bar under different conditions of loading. The magnitude (2 or 4 kg) and location (shoulders, waist, and ankles) of load systematically influenced the overall swing duration as well as the relative timing of movements at the joints. An analysis of the mechanical constraints operating suggested that the gymnast should be considered as a pendulum of variable length. Increasing and decreasing pendulum length at appropriate phases of the swing effectively allows energy to be injected into the system, thereby compensating the energy lost to friction. A sharp negative peak in the relative rate of change of pendulum length, characteristic of the upward swing phase of all gymnasts, was found to invariably occur at a particular value of the first-order time-to-closure of the body orientation gap with respect to the vertical. The presence of this invariant suggested that the gymnasts organize their behavior on the basis of such a first-order temporal relation.

Spatial neglect can be accompanied by a pusher syndrome (PS) which is characterized by a postural deviation towards the contralesional side. In this study, the representation of the body orientation in the horizontal plane was evaluated in neglect patients with and without PS. The participants had to align a luminous rod with the straight ahead direction, a method allowing the measure of both horizontal components of subjective straight ahead, i.e. lateral shift and yaw rotation. Eighteen patients with a lesion of the right hemisphere were compared with ten healthy participants. Patients had neglect and PS (P+N+; n=3), neglect only (P-N+; n=10), or neither neglect nor PS (P-N-; n=5). P+N+ patients showed a significant leftward shift contrasting with the rightward shift of P-N+. No shift occurred in patients without neglect and controls. No significant yaw error was recorded in any groups. The original result of this study was an inversion of the sign of the bias in neglect patients with PS. This could be related to the postural disorders characterizing this syndrome, and which are opposite to those usually observed in spatial neglect. Thus, these data suggest a link between disorders of spatial representations and disorders of posture.

SUMMARYPorpoise echolocation has been studied previously, mainly in target detection experiments using stationed animals and steel sphere targets, but little is known about the acoustic behaviour of free-swimming porpoises echolocating for prey. Here, we used small onboard sound and orientation recording tags to study the echolocation behaviour of free-swimming trained porpoises as they caught dead, freely drifting fish. We analysed porpoise echolocation behaviour leading up to and following prey capture events,including variability in echolocation in response to vision restriction, prey species, and individual porpoise tested. The porpoises produced echolocation clicks as they searched for the fish, followed by fast-repetition-rate clicks(echolocation buzzes) when acquiring prey. During buzzes, which usually began when porpoises were about 1–2 body lengths from prey, tag-recorded click levels decreased by about 10 dB, click rates increased to over 300 clicks per second, and variability in body orientation (roll) increased. Buzzes generally continued beyond the first contact with the fish, and often extended until or after the end of prey handling. This unexplained continuation of buzzes after prey capture raises questions about the function of buzzes, suggesting that in addition to providing detailed information on target location during the capture, they may serve additional purposes such as the relocation of potentially escaping prey. We conclude that porpoises display the same overall acoustic prey capture behaviour seen in larger toothed whales in the wild,albeit at a faster pace, clicking slowly during search and approach phases and buzzing during prey capture.

In an effort to document symptoms of shortterm stress in culture tanks, juvenile mahimahi (or dolphins, Coryphaena hippurus) were held in 500–700 L seawater at densities of about 0.1 fish/L and subjected to continuous changes in temperature and salinity over several hours. Ventilation rate, indexed by rate of opercular beat, and behavior patterns including body orientation and position within tanks were recorded. Ventilation rate was relatively sensitive to temperature change, and increased linearly with rising temperature until stress symptoms, including mortality, began near 30°C. Decreasing temperature to 16°C reduced ventilation rate; there was no mortality, but the fish ceased feeding. Decreasing salinity from 35‰ to 0‰ produced no significant change in ventilation rate, no mortality, and no qualitative effect on feeding vigor (at 9.5‰, the only value tested). All fish tested survived 1 h at 0‰. Behavior at high temperature resembled that reported for freshwater fishes under severe high-temp...

The influence of culture, gender, and age on proxemic and haptic behavior was investigated in this observational field study. Video recordings of 253 naturally-occurring dyadic interactions in the Netherlands, France, and England were analyzed by trained coders. Contrary to expectations, Hall's hypothesis regarding the proxemic and haptic norms of contact and noncontact cultures was not well supported. Among seated interactants, Dutch dyads maintained greater distances than French and English dyads, but French dyads were less proximate than were English dyads. The body orientation of French dyads was more direct than it was for Dutch or English dyads. In addition, with the exception of limited data on touch, neither the gender-composition of the dyad nor the gender of the individual affected the distances or body orientations of the interactants as would be expected according to traditional sex-role socialization processes. Age, as well, did not influence proxemic or haptic behavior. Results are discussed, primarily with respect to the research methods used in this and in previous investigations.

International audience; The present paper aims at critically reviewing the most outstanding and recent studies regarding the control of body orientation in the vertical space. A first part defines the general concepts used throughout this manuscript. The second part investigates the vertical perception and the main factors which affect it, while trying to overcome the five areas of theoretical and experimental controversies we have identified in the literature. The third part of this review presents the different theoretical models of the vertical perception and body orientation in space. Finally, the last part focuses on the functional coupling between perception of the vertical and orientation of the body in space. It considers more particularly how these two dimensions interact for explaining the observed behaviors.

Different species, from mollusk to man, actively maintain a basic body posture (that is a particular orientation of their body in space) due to the activity of postural control system. For example, marine mollusk Clione and man maintain the vertical (headup orientation), the fish and terrestrial quadrupeds maintain the dorsal side-up body orientation. Deviations in any plane from this orientation evoke corrective movements, which lead to a restoration of the initial orientation. The stabile posture also presents a basis on which voluntary movements of different parts of the body can be superimposed. Maintenance of body posture is a non-volitional activity that is based, in many species, on innate neural mechanisms. Postural systems differ from those for movement control in their behavioral goals. The systems for movement control cause a movement of the whole body or its segments from one position in space to the other, as in walking or reaching. The systems for postural control prevent movements. they stabilize a position (or orientation) of the body in space, or orientation of its segments in space and in relation to each other.

Background: To date, there are very few studies on postural stability in older adults using body movement recordings to capture the postural movement pattern. Moreover, the importance of proprioception at key areas such as the calf or neck on the postural movement pattern in older adults has rarely been investigated. Objective: To investigate whether the body movement coordination strategy to calf or neck vibration was affected by aging. Methods: Body movement measurements were taken at five locations (ankle, knee, hip, shoulder and head) from 18 younger (mean age 29.1 years) and 16 older (mean age 71.5 years) adult subjects using a 3D movement measuring system while subjected to 50 s of pseudo-random calf or neck vibratory stimulation pulses with eyes open or closed. The positions from the knee, hip, shoulder and head markers were correlated against one another to give an indication of the body coordination. Results: During quiet standing, older adults had greater correlation between the head and trunk than the young. There was an age effect in the body movement coordination strategy. Older adults had a different movement pattern with neck vibration involving mainly more independent knee movements, indicating balance difficulty. Conclusions: Neck vibration affects the movement pattern in older adults more compared with younger adults and calf vibration, suggesting that, the regulation of body orientation in older adults is more difficult, especially during cervical proprioceptive disturbances.

Two experiments were conducted to assess whether the orientation of the body at the time of test affects the efficiency with which people reason about spatial relations that are encoded in memory through symbolic media. Experiment 1 used depicted spatial layouts while Experiment 2 used described environments. In contrast to previous studies with directly-experienced spatial layouts, the present experiments revealed no sensorimotor influences on performance. Differences in reasoning about immediate and non-immediate environments are thus discussed. Furthermore, the same patterns of findings (i.e., normal alignment effects) were observed in the two experiments supporting the idea of functional equivalence of spatial representations derived from different modalities.

We demonstrate by means of simple, noninvasive methods (analysis of satellite images, field observations, and measuring “deer beds” in snow) that domestic cattle ( n = 8,510 in 308 pastures) across the globe, and grazing and resting red and roe deer ( n = 2,974 at 241 localities), align their body axes in roughly a north–south direction. Direct observations of roe deer revealed that animals orient their heads northward when grazing or resting. Amazingly, this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters. Because wind and light conditions could be excluded as a common denominator determining the body axis orientation, magnetic alignment is the most parsimonious explanation. To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north. This study reveals the magnetic alignment in large mammals based on statistically sufficient sample sizes. Our findings open horizons for the study of magnetoreception in general and are of potential significance for applied ethology (husbandry, animal welfare). They challenge neuroscientists and biophysics to explain the proximate mechanisms.