217 research outputs found
How to diagnose plantaris tendon involvement in midportion Achilles tendinopathy - clinical and imaging findings
Background: The purpose of this investigation was to evaluate if clinical assessment, Ultrasound + Colour Doppler (US + CD) and Ultrasound Tissue Characterisation (UTC) can be useful in detecting plantaris tendon involvement in patients with midportion Achilles tendinopathy. Methods: Twenty-three tendons in 18 patients (14 men, mean age: 37 years and 4 women: 44 years) (5 patients with bilateral tendons) with midportion Achilles tendinopathy were surgically treated with a scraping procedure and plantaris tendon removal. For all tendons, clinical assessment, Ultrasound + Colour Doppler (US + CD) examination and Ultrasound Tissue Characterisation (UTC) were performed. Results: At surgery, all 23 cases had a plantaris tendon located close to the medial side of the Achilles tendon. There was vascularised fat tissue in the interface between the Achilles and plantaris tendons. Clinical assessment revealed localised medial activity-related pain in 20/23 tendons and focal medial tendon tenderness in 20/23 tendons. For US + CD, 20/23 tendons had a tendon-like structure interpreted to be the plantaris tendon and localised high blood flow in close relation to the medial side of the Achilles. For UTC, 19/23 tendons had disorganised (type 3 and 4) echopixels located only in the medial part of the Achilles tendon indicating possible plantaris tendon involvement. Conclusions: US + CD directly, and clinical assessment indirectly, can detect a close by located plantaris tendon in a high proportion of patients with midportion Achilles tendinopathy. UTC could complement US + CD and clinical assessment by demonstrating disorganised focal medial Achilles tendon structure indicative of possible plantaris involvement
Motor-cortical beta oscillations are modulated by correctness of observed action
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73550.pdf (Publisher’s version ) (Closed access)How humans understand the intention of others’ actions remains controversial. Some authors have suggested that intentions are recognized by means of a motor simulation of the observed action with the mirror-neuron system [1–3]. Others emphasize that intention recognition is an inferential process, often called ‘‘mentalizing’’ or employing a ‘‘theory of mind,’’ which activates areas well outside the motor system [4–6]. Here, we assessed the contribution of brain regions involved in motor simulation and mentalizing for understanding action intentions via functional brain imaging. Results show that the inferior frontal gyrus (part of the mirror-neuron system) processes the intentionality of an observed action on the basis of the visual properties of the action, irrespective of whether the subject paid attention to the intention or not. Conversely, brain areas that are part of a ‘‘mentalizing’’ network become active when subjects reflect about the intentionality of an observed action, but they are largely insensitive to the visual properties of the observed action. This supports the hypothesis that motor simulation and mentalizing have distinct but complementary functions for the recognition of others’ intentions
Learning to use novel objects: A training study on the acquisition of novel action representations
Many studies have suggested that the motor system is organized in a hierarchical fashion, around the prototypical end location associated with using objects. However, most studies supporting the hierarchical view have used well-known actions and objects that are highly over-learned. Accordingly, at present it is unclear if the hierarchical principle applies to learning the use of novel objects as well. In the present study we found that when learning to use a novel object subjects acquired an action representation of the end location associated with using the object, as evidenced by slower responses in an action observation task, when the object was presented at an incorrect end location. By showing the importance of knowledge about end locations when learning to use a novel object, the present study suggests that end locations are a fundamental organizing feature of the human motor system
Rewiring phospholipid biosynthesis reveals resilience to membrane perturbations and uncovers regulators of lipid homeostasis
The organelles of eukaryotic cells differ in their membrane lipid composition. This heterogeneity is achieved by the localization of lipid synthesizing and modifying enzymes to specific compartments, as well as by intracellular lipid transport that utilizes vesicular and non‐vesicular routes to ferry lipids from their place of synthesis to their destination. For instance, the major and essential phospholipids, phosphatidylethanolamine (PE) and phosphatidylcholine (PC), can be produced by multiple pathways and, in the case of PE, also at multiple locations. However, the molecular components that underlie lipid homeostasis as well as the routes allowing their distribution remain unclear. Here, we present an approach in which we simplify and rewire yeast phospholipid synthesis by redirecting PE and PC synthesis reactions to distinct subcellular locations using chimeric enzymes fused to specific organelle targeting motifs. In rewired conditions, viability is expected to depend on homeostatic adaptation to the ensuing lipostatic perturbations and on efficient interorganelle lipid transport. We therefore performed genetic screens to identify factors involved in both of these processes. Among the candidates identified, we find genes linked to transcriptional regulation of lipid homeostasis, lipid metabolism, and transport. In particular, we identify a requirement for Csf1—an uncharacterized protein harboring a Chorein‐N lipid transport motif—for survival under certain rewired conditions as well as lipidomic adaptation to cold, implicating Csf1 in interorganelle lipid transport and homeostatic adaptation
Conceptual knowledge for understanding other’s actions is organized primarily around action goals
Semantic knowledge about objects entails both knowing how to grasp an object (grip-related knowledge) and what to do with an object (goal-related knowledge). Considerable evidence suggests a hierarchical organization in which specific hand-grips in action execution are most often selected to accomplish a remote action goal. The present study aimed to investigate whether a comparable hierarchical organization of semantic knowledge applies to the recognition of other’s object-directed actions as well. Correctness of either the Grip (hand grip applied to the object) or the Goal (end-location at which an object was directed) were manipulated independently in two experiments. In Experiment 1, subjects were required to attend selectively to either the correctness of the grip or the goal of the observed action. Subjects were faster when attending to the goal of the action and a strong interference of goal-violations was observed when subjects attended to the grip of the action. Importantly, observation of irrelevant goal- or grip-related violations interfered with making decisions about the correctness of the relevant dimension only when the relevant dimension was correct. In contrast, in Experiment 2, when subjects attended to an action-irrelevant stimulus dimension (i.e. orientation of the object), no interference of goal- or grip-related violations was found, ruling out the possibility that interference-effects result from perceptual differences between stimuli. These findings suggest that understanding the correctness of an action selectively recruits specialized, but interacting networks, processing the correctness of goal- and grip-specific information during action observation
Аналіз стійкості вибійних компоновок на проектній траєкторії
Рассмотрены основные причины, оказывающие
дестабилизирующее влияние на роботу компоновок
низа бурильной колонны. Проведён анализ процесса
износа опорноцентрирующих элементов забойной
компоновки и его влияния на изменение её конструктивных параметров. Получены графические зависимости, позволяющие оценить степень стойкости различных типов забойных компоновок на проектной траектории. Сделаны основные выводы,
касающиеся поведения различных типов компоновок
при воздействии на них дестабилизирующих факторовThe basic reasons, causing destabilizing influence
on the work of drilling string assembly are reviewed.
The analysis of wear out process of strong centralizing
elements bottom drilling string assembly and its
influence to change of its constructive properties is
done. The graphic dependences, giving an opportunity
to value the stage of firmness of different types of
bottom drilling string assemblies on projected trajectory
are given. The conclusion about conduct of different
types of drilling string assemblies during influence on it
destabilizing factors is draw
How the Human Brain Goes Virtual: Distinct Cortical Regions of the Person-Processing Network Are Involved in Self-Identification with Virtual Agents
Millions of people worldwide engage in online role-playing with their avatar, a virtual agent that represents the self. Previous behavioral studies have indicated that many gamers identify more strongly with their avatar than with their biological self. Through their avatar, gamers develop social networks and learn new social-cognitive skills. The cognitive neurosciences have yet to identify the neural processes that underlie self-identification with these virtual agents. We applied functional neuroimaging to 22 long-term online gamers and 21 nongaming controls, while they rated personality traits of self, avatar, and familiar others. Strikingly, neuroimaging data revealed greater avatar-referential cortical activity in the left inferior parietal lobe, a region associated with self-identification from a third-person perspective. The magnitude of this brain activity correlated positively with the propensity to incorporate external body enhancements into one's bodily identity. Avatar-referencing furthermore recruited greater activity in the rostral anterior cingulate gyrus, suggesting relatively greater emotional self-involvement with one's avatar. Post-scanning behavioral data revealed superior recognition memory for avatar relative to others. Interestingly, memory for avatar positively covaried with play duration. These findings significantly advance our knowledge about the brain's plasticity to self-identify with virtual agents and the human cognitive-affective potential to live and learn in virtual worlds
Development of a value-based healthcare burns core set for adult burn care
Background: Value-based healthcare (VBHC) is increasingly implemented in healthcare worldwide. Transparent measurement of the outcomes most important and relevant to patients is essential in VBHC, which is supported by a core set of most important quality indicators and outcomes. Therefore, the aim of this study was to develop a VBHC-burns core set for adult burn patients. Methods: A three-round modified national Delphi study, including 44 outcomes and 24 quality indicators, was conducted to reach consensus among Dutch patients, burn care professionals and researchers. Items were rated on a nine-point Likert scale and selected if ≥ 70% in each group considered an item ‘important’. Subsequently, instruments quantifying selected outcomes were identified based on a literature review and were chosen in a consensus meeting using recommendations from the Dutch consensus-based standard set and the Dutch Centre of Expertise on Health Disparities. Time assessment points were chosen to reflect the burn care and patient recovery process. Finally, the initial core set was evaluated in practice, leading to the adapted VBHC-burns core set. Results: Twenty-seven patients, 63 burn care professionals and 23 researchers participated. Ten outcomes and four quality indicators were selected in the Delphi study, including the outcomes pain, wound healing, physical activity, self-care, independence, return to work, depression, itching, scar flexibility and return to school. Quality indicators included shared decision-making (SDM), the number of patients receiving aftercare, determination of burn depth, and assessment of active range of motion. After evaluation of its use in clinical practice, the core set included all items except SDM, which are assessed by 9 patient-reported outcome instruments or measured in clinical care. Assessment time points included are at discharge, 2 weeks, 3 months, 12 months after discharge and annually afterwards. Conclusion: A VBHC-burns core set was developed, consisting of outcomes and quality indicators that are important to burn patients and burn care professionals. The VBHC-burns core set is now systemically monitored and analysed in Dutch burn care to improve care and patient relevant outcomes. As improving burn care and patient relevant outcomes is important worldwide, the developed VBHC-burns core set could be inspiring for other countries.</p
Imitation of hand and tool actions is effector-independent
Following the theoretical notion that tools often extend one’s body, in the present study, we investigated whether imitation of hand or tool actions is modulated by effector-specific information. Subjects performed grasping actions toward an object with either a handheld tool or their right hand. Actions were initiated in response to pictures representing a grip at an object that could be congruent or incongruent with the required action (grip-type congruency). Importantly, actions could be cued by means of a tool cue, a hand cue, and a symbolic cue (effector-type congruency). For both hand and tool actions, an action congruency effect was observed, reflected in faster reaction times if the observed grip type was congruent with the required movement. However, neither hand actions nor tool actions were differentially affected by the effector represented in the picture (i.e., when performing a tool action, the action congruency effect was similar for tool cues and hand cues). This finding suggests that imitation of hand and tool actions is effector-independent and thereby supports generalist rather than specialist theories of imitation
Performance related factors are the main determinants of the von Willebrand factor response to exhaustive physical exercise
Background: Physical stress triggers the endothelium to release von Willebrand Factor (VWF) from the Weibel Palade bodies. Since VWF is a risk factor for arterial thrombosis, it is of great interest to discover determinants of VWF response to physical stress. We aimed to determine the main mediators of the VWF increase by exhaustive physical exercise. Methods: 105 healthy individuals (18-35 years) were included in this study. Each participant performed an incremental exhaustive exercise test on a cycle ergometer. Respiratory gas exchange measurements were obtained while cardiac function was continuously monitored. Blood was collected at baseline and directly after exhaustion. VWF antigen (VWF:Ag) levels, VWF collagen binding (VWF:CB) levels, ADAMTS13 activity and common variations in Syntaxin Binding Protein-5 (STXBP5, rs1039084 and rs9399599), Syntaxin-2 (STX2, rs7978987) and VWF (promoter, rs7965413) were determined. Results: The median VWF:Ag level at baseline was 0.94 IU/mL [IQR 0.8-1.1] and increased with 47% [IQR 25-73] after exhaustive exercise to a median maximum VWF:Ag of 1.38 IU/mL [IQR 1.1-1.8] (p<0.0001). VWF:CB levels and ADAMTS13 activity both also increased after exhaustive exercise (median increase 43% and 12%, both p<0.0001). The strongest determinants of the VWF:Ag level increase are performance related (p<0.0001). We observed a gender difference in VWF:Ag response to exercise (females 1.2 IU/mL; males 1.7 IU/mL, p = 0.001), which was associated by a difference in performance. Genetic variations in STXBP5, STX2 and the VWF promoter were not associated with VWF:Ag levels at baseline nor with the VWF:Ag increase. Conclusions: VWF:Ag levels strongly increase upon exhaustive exercise and this increase is strongly determined by physical fitness level and the intensity of the exercise, while there is no clear effect of genetic variation in STXBP5, STX2 and the VWF promoter
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