Search results for "Movement"
showing 10 items of 2021 documents
Action Representation in Patients with Bilateral Vestibular Impairments
2011
During mental actions subjects feel themselves performing a movement without any corresponding motor output. Although broad information is available regarding the influence of central lesions on action representation, little is known about how peripheral damages affect mental events. In the current study, we investigated whether lack of vestibular information influences action representation. Twelve healthy adults and twelve patients with bilateral vestibular damage actually performed and mentally simulated walking and drawing. The locomotor paths implied one (first walking task) and four (second walking task) changes in the walking direction. In the drawing task, participants drew on a she…
Co-registering kinematics and evoked related potentials during visually guided reach-to-grasp movements.
2013
Background:In non-human primates grasp-related sensorimotor transformations are accomplished in a circuit involving the anterior intraparietal sulcus (area AIP) and both the ventral and the dorsal sectors of the premotor cortex (vPMC and dPMC, respectively). Although a human homologue of such a circuit has been identified, the time course of activation of these cortical areas and how such activity relates to specific kinematic events has yet to be investigated.Methodology/Principal Findings:We combined kinematic and event-related potential techniques to explicitly test how activity within human grasping-related brain areas is modulated in time. Subjects were requested to reach towards and g…
Enhanced Activity of Meprin-α, a Pro-Migratory and Pro-Angiogenic Protease, in Colorectal Cancer
2011
Meprin-α is a metalloprotease overexpressed in cancer cells, leading to the accumulation of this protease in a subset of colorectal tumors. The impact of increased meprin-α levels on tumor progression is not known. We investigated the effect of this protease on cell migration and angiogenesis in vitro and studied the expression of meprin-α mRNA, protein and proteolytic activity in primary tumors at progressive stages and in liver metastases of patients with colorectal cancer, as well as inhibitory activity towards meprin-α in sera of cancer patient as compared to healthy controls. We found that the hepatocyte growth factor (HGF)- induced migratory response of meprin-transfected epithelial c…
Segmental contribution to forces in vertical jump.
1978
Performance of a vertical jump was analyzed with respect to the contribution of the different body segments to the forces acting on the whole body center of gravity. Both cinematograph and force-platform techniques were employed. The data disclosed that the take-off velocity in vertical jumps was caused by the different components as follows: knee extension 56%, plantar flexion 22%, trunk extension 10%, arm swing 10%, and head swing 2%. However, the average take-off velocity of the total performance (3.03 m/s) was only 76% from the theoretical maximum calculated from the segmental analyses. Optimal timing of the segmental performances was calculated to increase this “efficiency” to 84%. Gre…
Evidence of beat perception via purely tactile stimulation
2008
Humans can easily tap in synchrony with an auditory beat but not with an equivalent visual rhythmic sequence, suggesting that the sensation of meter (i.e. of an underlying regular pulse) may be inherently auditory. We assessed whether the perception of meter could also be felt with tactile sensory inputs. We found that, when participants were presented with identical rhythmic sequences filled with either short tones or hand stimulations, they could more efficiently tap in synchrony with strongly rather than weakly metric sequences. These observations suggest that non-musician adults can extract the metric structure of purely tactile rhythms and use it to tap regularly with the beat induced …
Influence of competition on performance factors in under-19 soccer players at national league level.
2020
The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defen…
Scavengers on the move: behavioural changes in foraging search patterns during the annual cycle
2013
Background: Optimal foraging theory predicts that animals will tend to maximize foraging success by optimizing search strategies. However, how organisms detect sparsely distributed food resources remains an open question. When targets are sparse and unpredictably distributed, a Lévy strategy should maximize foraging success. By contrast, when resources are abundant and regularly distributed, simple Brownian random movement should be sufficient. Although very different groups of organisms exhibit Lévy motion, the shift from a Lévy to a Brownian search strategy has been suggested to depend on internal and external factors such as sex, prey density, or environmental context. However, animal re…
Three new chondrosarcoma cell lines: one grade III conventional central chondrosarcoma and two dedifferentiated chondrosarcomas of bone
2012
Abstract Background Chondrosarcoma is the second most common primary sarcoma of bone. High-grade conventional chondrosarcoma and dedifferentiated chondrosarcoma have a poor outcome. In pre-clinical research aiming at the identification of novel treatment targets, the need for representative cell lines and model systems is high, but availability is scarce. Methods We developed and characterized three cell lines, derived from conventional grade III chondrosarcoma (L835), and dedifferentiated chondrosarcoma (L2975 and L3252) of bone. Proliferation and migration were studied and we used COBRA-FISH and array-CGH for karyotyping and genotyping. Immunohistochemistry for p16 and p53 was performed a…
Angiotensin II-Induced Mononuclear Leukocyte Interactions with Arteriolar and Venular Endothelium Are Mediated by the Release of Different CC Chemoki…
2006
Abstract Angiotensin II (Ang-II) is associated with atherogenesis and arterial subendothelial mononuclear leukocyte infiltration. We have demonstrated that Ang-II causes the initial attachment of mononuclear cells to the arteriolar endothelium. We now report on the contribution of CC chemokines to this response. Intraperitoneal administration of 1 nM Ang-II induced MCP-1, RANTES, and MIP-1α generation, maximal at 4 h, followed by mononuclear leukocyte recruitment at 8 and 24 h. Using intravital microscopy within the rat mesenteric microcirculation 4 h after exposure to 1 nM Ang-II, arteriolar mononuclear cell adhesion was 80–90% inhibited by pretreatment with Met-RANTES, a CCR1 and CCR5 ant…
Essential thalamic contribution to slow waves of natural sleep
2013
Slow waves represent one of the prominent EEG signatures of non-rapid eye movement (non-REM) sleep and are thought to play an important role in the cellular and network plasticity that occurs during this behavioral state. These slow waves of natural sleep are currently considered to be exclusively generated by intrinsic and synaptic mechanisms within neocortical territories, although a role for the thalamus in this key physiological rhythm has been suggested but never demonstrated. Combining neuronal ensemble recordings, microdialysis, and optogenetics, here we show that the block of the thalamic output to the neocortex markedly (up to 50%) decreases the frequency of slow waves recorded dur…