IL-15 is believed to play a role in the beneficial impact of exercise on muscle energy metabolism. However, previous studies have generally used supraphysiological levels of IL-15 that do not ...represent contraction-induced IL-15 secretion.
L6 myotubes were treated acutely (3 h) and chronically (48 h) with concentrations of IL-15 mimicking circulating (1–10 pg/ml) and muscle interstitial (100 pg/ml −20 ng/ml) IL-15 levels with the aim to better understand its autocrine/paracrine role on muscle glucose uptake and mitochondrial function.
Acute exposure to IL-15 levels representing muscle interstitial IL-15 increased basal glucose uptake without affecting insulin sensitivity. This was accompanied by increased mitochondrial oxidative functions in association with increased AMPK pathway and formation of complex III-containing supercomplexes. Conversely, chronic IL-15 exposure resulted in a biphasic effect on mitochondrial oxidative functions and ETC supercomplex formation was increased with low IL-15 levels but decreased with higher IL-15 concentrations. The AMPK pathway was activated only by high levels of chronic IL-15 treatment. Similar results were obtained in skeletal muscle from muscle-specific IL-15 overexpressing mice that show very high circulating IL-15 levels.
Acute IL-15 treatment that mimics local IL-15 concentrations enhances muscle glucose uptake and mitochondrial oxidative functions. That mitochondria respond differently to different levels of IL-15 during chronic treatments indicates that IL-15 might activate two different pathways in muscle depending on IL-15 concentrations.
Our results suggest that IL-15 may act in an autocrine/paracrine fashion and be, at least in part, involved in the positive effect of exercise on muscle energy metabolism.
•Acute IL-15 improves muscle glucose uptake in association with AMPK pathway activation.•Acute IL-15 improves muscle mitochondrial oxidative functions together with ETC supercomplex formation.•Chronic IL-15 effects on mitochondrial function/supercomplexes are concentration-dependant.•IL-15 might activate two different pathways in muscle depending on its concentration.
Grasp Representations Depend on Knowledge and Attention Chua, Kao-Wei; Bub, Daniel N; Masson, Michael E. J ...
Journal of experimental psychology. Learning, memory, and cognition,
02/2018, Letnik:
44, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Seeing pictures of objects activates the motor cortex and can have an influence on subsequent grasping actions. However, the exact nature of the motor representations evoked by these pictures is ...unclear. For example, action plans engaged by pictures could be most affected by direct visual input and computed online based on object shape. Alternatively, action plans could be influenced by experience seeing and grasping these objects. We provide evidence for a dual-route theory of action representations evoked by pictures of objects, suggesting that these representations are influenced by both direct visual input and stored knowledge. We find that that familiarity with objects has a facilitative effect on grasping actions, with knowledge about the object's canonical orientation or its name speeding grasping actions for familiar objects compared to novel objects. Furthermore, the strength of contributions from each route to action can be modulated by the manner in which the objects are attended. Thus, evocation of grasping representations depends on an interaction between one's familiarity with perceived objects and how those objects are attended while making grasp actions.
When listening to a sentence describing an interaction with a manipulable object, understanding the actor's intentions is shown to have a striking influence on action representations evoked during ...comprehension. Subjects performed a cued reach and grasp response while listening to a context sentence. Responses were primed when they were consistent with the proximal intention of an actor ("John lifted the cell phone..."), but this effect was evanescent and appeared only when sentences mentioned the proximal intention first. When the sentence structure was changed to mention the distal intention first ("To clear the shelf..."), priming effects were no longer context specific and actions pertaining to the function of an object were clearly favored. These results are not compatible with a straightforward mental-simulation account of sentence comprehension but instead reflect a hierarchy of intentions distinguishing how and why actions are performed.
We examine the nature of motor representations evoked during comprehension of written sentences describing hand actions. We distinguish between two kinds of hand actions: a functional action, applied ...when using the object for its intended purpose, and a volumetric action, applied when picking up or holding the object. In Experiment 1, initial activation of both action representations was followed by selection of the functional action, regardless of sentence context. Experiment 2 showed that when the sentence was followed by a picture of the object, clear context-specific effects on evoked action representations were obtained. Experiment 3 established that when a picture of an object was presented alone, the time course of both functional and volumetric actions was the same. These results provide evidence that representations of object-related hand actions are evoked as part of sentence processing. In addition, we discuss the conditions that elicit context-specific evocation of motor representations.
The DARWIN observatory is a proposed next-generation experiment to search for particle dark matter and for the neutrinoless double beta decay of
136
Xe. Out of its 50 t total natural xenon inventory, ...40 t will be the active target of a time projection chamber which thus contains about 3.6 t of
136
Xe. Here, we show that its projected half-life sensitivity is
2.4
×
10
27
year
, using a fiducial volume of 5 t of natural xenon and 10 year of operation with a background rate of less than 0.2 events/(t
·
year) in the energy region of interest. This sensitivity is based on a detailed Monte Carlo simulation study of the background and event topologies in the large, homogeneous target. DARWIN will be comparable in its science reach to dedicated double beta decay experiments using xenon enriched in
136
Xe.
Mining slopes, electrical power generation dams and several big construction enterprises demands continuous inspections. The size and diversity of these structures demands high precision and portable ...approach. In such environments, 3D reconstruction methodologies are able to capture and analyze the real world in detail. However, the accuracy and precision can affect the ability to process and interpret the acquired data. For instance, laser scanning is a very accurate method and can deliver a higher quality result. Meanwhile, 3D photogrammetry using a single camera and Structure From Motion (SFM) have their performance correlated with the image quality. In a typical application, 3D data from reconstruction is pre-processed by a specialist. Then, it is stored for comparison and analyzed over time. The posterior analysis has several challenges associated with the reconstruction process characteristics. Several techniques have been developed to allow the comparison of point cloud captured at different epochs. Therefore, this research work presents a new methodology to perform alignment and comparison of point clouds, namely 3D-CP2, an acronym for 3D Correspondence and Point Projection. This method intends to analyze the point cloud motion to be applied in terrestrial 3D SFM reconstructions. Besides, the technique can also be used in many other related applications. The methodology developed in this work is applied in controlled experiments and real use cases to show its potential for point cloud displacements analysis. The results showed that the proposed method is efficient and can produce results more accurately than the referenced literature.
Attending to a manipulable object evokes a mental representation of hand actions associated with the object's form and function. In one view, these representations are sufficiently abstract that ...their competing influence on an unrelated action is confined to the planning stages of movement and does not affect its on-line control. Alternatively, an object may evoke action representations that affect the entire trajectory of an unrelated grasping action. We developed a new methodology to statistically analyze the forward motion and rotation of the hand and fingers under different task conditions. Using this novel approach, we established that a grasping action executed after seeing a photograph of an object is systematically perturbed even into the late stages of its trajectory by the competing influence of the grasping posture associated with the object. Our results show that embodied effects of conceptual knowledge continuously modulate the hand in flight.
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