Temporally precise movement-based predictions in the mouse auditory cortex

Many of the sensations experienced by an organism are caused by their own actions, and accurately anticipating both the sensory features and timing of self-generated stimuli is crucial to a variety of behaviors. In the auditory cortex, neural responses to self-generated sounds exhibit frequency-specific suppression, suggesting that movement-based predictions may be implemented early in sensory processing. Yet it remains unknown whether this modulation results from a behaviorally specific and temporally precise prediction, nor is it known whether corresponding expectation signals are present locally in the auditory cortex. To address these questions, we trained mice to expect the precisely timed acoustic outcome of a forelimb movement using a closed-loop sound-generating lever. Dense neuronal recordings in the auditory cortex revealed suppression of responses to self-generated sounds that was specific to the expected acoustic features, specific to a precise time within the movement, and specific to the movement that was coupled to sound during training. Predictive suppression was concentrated in L2/3 and L5, where deviations from expectation also recruited a population of prediction-error neurons that was otherwise unresponsive. Recording in the absence of sound revealed abundant movement signals in deep layers that were biased toward neurons tuned to the expected sound, as well as temporal expectation signals that were present throughout the cortex and peaked at the time of expected auditory feedback. Together, these findings reveal that predictive processing in the mouse auditory cortex is consistent with a learned internal model linking a specific action to its temporally precise acoustic outcome, while identifying distinct populations of neurons that anticipate expected stimuli and differentially process expected versus unexpected outcomes.

Modulation of cutaneous responses in the cuneate nucleus of macaques during active movement

To achieve stable and precise movement execution, the sensorimotor system integrates exafferent sensory signals originating from interactions with the external world and reafferent signals caused by our own movements. This barrage of sensory information is regulated such that behaviorally relevant signals are boosted at the expense of irrelevant ones. For example, sensitivity to touch is reduced during movement - when cutaneous signals caused by skin stretch are expected and uninteresting - a phenomenon reflected in a decreased cutaneous responsiveness in thalamus and cortex. Some evidence suggests that movement gating of touch may originate from the cuneate nucleus (CN), the first recipient of signals from tactile nerve fibers along the dorsal columns medial lemniscal pathway. To test this possibility, we intermittently delivered mechanical pulses to the receptive fields (RFs) of identified cutaneous CN neurons as monkeys performed a reach-to-grasp task. As predicted, we found that the cutaneous responses of individual CN neurons were reduced during movement. However, this movement gating of cutaneous signals was observed for CN neurons with RFs on the arm but not those with RFs on the hand. We conclude that sensory gating occurs in the first processing stage along the somatosensory neuraxis and sculpts incoming signals according to their task relevance.

Influence of Microstepping Signal Shape on Shaft Movement Precision and Torque Variation of the Stepper Motor

Stepper motors are widely used in many applications where discrete, precise movement is required. There is a variety of dedicated stepper motor controllers (sometimes referred to as “step sticks”) available on the market. Those controllers provide a number of different motor control schemes that vary by aspects like current control method, reference current shape or maximum resolution increase (microstepping). The two most widely acknowledged signal shapes are sine-cosine microstepping and quadrature microstepping. The choice of the control scheme impacts torque output, torque variation, positioning error and maximum power supply requirements. This paper presents a family of generalised microstepping signal shapes, ranging from sine-cosine microstepping to quadrature microstepping. Derivation of signal shapes as well as their mathematical analyses are provided. Those signals are then implemented on the control board. A series of experiments is performed on a test bench to analyse the influence of different signal shapes on the performance of the motor in both load and no load conditions. The comparison of the new generalized shapes influence on the motor operation to the commonly used sine-cosine and quadrature control is provided.

Corticokinematic coherence is stronger to regular than irregular proprioceptive stimulation of the hand

Proprioceptive afference can be investigated using corticokinematic coherence (CKC), which indicates coupling between limb kinematics and cortical activity. CKC has been quantified using proprioceptive stimulation (movement actuators) with fixed inter-stimulus interval (ISI). However, it is unclear how regularity of the stimulus sequence (jitter) affects CKC strength. Eighteen healthy volunteers (16 right-handed, 27.8±5.0 yrs, 7 females) participated in magnetoencephalography (MEG) session in which their right-index finger was continuously moved at ~3-Hz with constant 333 ms ISI or with 20% jitter (ISI 333±66 ms) using a pneumatic-movement actuator. Three minutes of data per condition was collected. Finger kinematics were recorded with a 3-axis accelerometer. CKC strength was defined as the peak coherence value in the Rolandic MEG gradiometer pair contralateral to the movement at 3-Hz. Both conditions resulted in significant coherence peaking in the gradiometers over the primary sensorimotor cortex. Constant stimulation yielded stronger CKC at 3 Hz (0.78±0.11 vs. 0.66±0.13, p<0.001) and its first harmonic (0.60±0.19 vs. 0.27±0.11, p<0.001) than irregular stimulation. Similarly, the respective sustained-movement evoked field was also stronger for constant stimulation. The results emphasize the importance of temporal stability of the proprioceptive stimulation sequence when quantifying CKC strength. The weaker CKC during irregular stimulation can be explained with temporal and thus spectral scattering of the paired peripheral and cortical events beyond the mean stimulation frequency. This impairs the signal-to-noise ratio of respective MEG signal and thus CKC strength. When accurately estimating and following changes in CKC strength, we suggest using precise movement actuators with constant stimulation sequence.

Magnetic tri-bead microrobot assisted near-infrared triggered combined photothermal and chemotherapy of cancer cells

Magnetic micro/nanorobots attracted much attention in biomedical fields because of their precise movement, manipulation, and targeting abilities. However, there is a lack of research on intelligent micro/nanorobots with stimuli-responsive drug delivery mechanisms for cancer therapy. To address this issue, we developed a type of strong covalently bound tri-bead drug delivery microrobots with NIR photothermal response azobenzene molecules attached to their carboxylic surface groups. The tri-bead microrobots are magnetic and showed good cytocompatibility even when their concentration is up to 200 µg/mL. In vitro photothermal experiments demonstrated fast NIR-responsive photothermal property; the microrobots were heated to 50 °C in 4 min, which triggered a significant increase in drug release. Motion control of the microrobots inside a microchannel demonstrated the feasibility of targeted therapy on tumor cells. Finally, experiments with lung cancer cells demonstrated the effectiveness of targeted chemo-photothermal therapy and were validated by cell viability assays. These results indicated that tri-bead microrobots have excellent potential for targeted chemo-photothermal therapy for lung cancer cell treatment.

CONTROL OF THE ELECTRON BEAM DEFLECTION SYSTEM OF AN ELECTRON BEAM INSTALLATION

This paper explores patterns of electronic beam movement by controlling the transverse axis of the bundle of the uniform magnetic field generated by the coils of the electronic gun. For electron beam processes, the type of process, the technological mode, the design dimensions of the electronic gun, and the shape of the machined parts determines beam motion. The free and precise movement on random trajectories determines the possible applications of the electron beam process in performing various scientific experiments on material processing.

LEARNING THE 3D POSE OF VEHICLES FROM 2D VEHICLE PATCHES

Estimating vehicle poses is crucial for generating precise movement trajectories from (surveillance) camera data. Additionally for real time applications this task has to be solved in an efficient way. In this paper we introduce a deep convolutional neural network for pose estimation of vehicles from image patches. For a given 2D image patch our approach estimates the 2D coordinates of the image representing the exact center ground point (cx, cy) and the orientation of the vehicle - represented by the elevation angle (e) of the camera with respect to the vehicle’s center ground point and the azimuth rotation (a) of the vehicle with respect to the camera. To train a accurate model a large and diverse training dataset is needed. Collecting and labeling such large amount of data is very time consuming and expensive. Due to the lack of a sufficient amount of training data we show furthermore, that also rendered 3D vehicle models with artificial generated textures are nearly adequate for training.

Pembiasaan Kegiatan Baris-Berbaris dalam Pembentukan Nilai Pendidikan Karakter Disiplin Siswa Kelas 2 SD Negeri 1 Kutosari

<p><em>Habit formed character, for instance: the habit of lining-up. The study aimed to describe the habit of lining up and to describe the habit of lining up to form discipline character. It was qualitative with a narrative approach. The procedures of the study were: 1) doing observation, 2) analyzing problem, 3) having problem statement, 4) doing research, 5) analyzing data, and 6) having data validity. The result showed that the habit of lining up in SD Negeri 1 Kutosari worked well. It was proven by some indicators: (1) precise movement based on the rules, (2) firmness of leader when giving command, (3) neatness in lining up, (4) consistency in lining up, (5) enthusiasm in lining up, (6) resemblance of movement. The lining up applied every morning in all grades. The second grade students of SD Negeri 1 Kutosari had discipline character. They showed several indicators: (1) arrived on time, (2) paid attention to the lesson, (3) did the homework, (4) obeyed school rules, (5) obeyed teacher's advice, (6) wore school uniform, and (7) had flag ceremony quietly.</em></p><p><strong>Keywords</strong><em>: Habit, Lining up, Discipline</em><em></em></p>

The primary motor cortex prospectively computes the spinal reflex

The spinal reflex transforms sensory signals to generate muscle activity. However, it is unknown how the motor cortex (MCx) takes the spinal reflex into account when performing voluntary limb movements. We simultaneously recorded the activity of the MCx, afferent neurons, and forelimb muscles in behaving monkeys. We decomposed muscle activity into subcomponents explained by the MCx or afferent activity using linear models. Long preceding activity in the MCx, which is responsible for subsequent afferent activity, had the same spatiotemporal contribution to muscle activity as afferent activity, indicating that the MCx drives muscle activity not only by direct descending activation but also by trans-afferent descending activation. Therefore, the MCx implements internal models that prospectively estimate muscle activation via the spinal reflex for precise movement control.