Reflex Movements Research Articles

Detection of the Milky Way reflex motion due to the Large Magellanic Cloud infall

The Large Magellanic Cloud is the most massive satellite galaxy of the Milky Way, with an estimated mass exceeding a tenth of the mass of the Milky Way. Just past its closest approach of about 50 kpc, and flying by the Milky Way at an astonishing speed of 327 km/s, the Large Magellanic Cloud can affect our Galaxy in a number of ways, including dislodging the Milky Way disc from the Galactic centre-of-mass. Here, we report evidence that the Milky Way disc is moving with respect to stellar tracers in the outer halo ($40<r<120$ kpc) at $v_{\rm travel}=32^{+4}_{-4}$ km/s, in the direction $(\ell,b)_{\rm apex}=(56^{+9}_{-9},-34^{+10}_{-9})$ degrees, which points at an earlier location on the LMC trajectory. The resulting reflex motion is detected in the kinematics of outer halo stars and Milky Way satellite galaxies with accurate distances, proper motions and line-of-sight velocities. Our results indicate that dynamical models of our Galaxy cannot neglect gravitational perturbations induced by the Large Magellanic Cloud infall, nor can observations of the stellar halo be treated in a reference frame that does not correct for disc reflex motion. Future spectroscopic surveys of the stellar halo combined with Gaia astrometry will allow for sophisticated modelling of the Large Magellanic Cloud trajectory across the Milky Way, constraining the dark matter distribution in both galaxies with unprecedented detail.

WhiskEras: A New Algorithm for Accurate Whisker Tracking.

Rodents engage in active touch using their facial whiskers: they explore their environment by making rapid back-and-forth movements. The fast nature of whisker movements, during which whiskers often cross each other, makes it notoriously difficult to track individual whiskers of the intact whisker field. We present here a novel algorithm, WhiskEras, for tracking of whisker movements in high-speed videos of untrimmed mice, without requiring labeled data. WhiskEras consists of a pipeline of image-processing steps: first, the points that form the whisker centerlines are detected with sub-pixel accuracy. Then, these points are clustered in order to distinguish individual whiskers. Subsequently, the whiskers are parameterized so that a single whisker can be described by four parameters. The last step consists of tracking individual whiskers over time. We describe that WhiskEras performs better than other whisker-tracking algorithms on several metrics. On our four video segments, WhiskEras detected more whiskers per frame than the Biotact Whisker Tracking Tool. The signal-to-noise ratio of the output of WhiskEras was higher than that of Janelia Whisk. As a result, the correlation between reflexive whisker movements and cerebellar Purkinje cell activity appeared to be stronger than previously found using other tracking algorithms. We conclude that WhiskEras facilitates the study of sensorimotor integration by markedly improving the accuracy of whisker tracking in untrimmed mice.

Formação inicial de professores conectados com as demandas da docência na contemporaneidade: tematizando o contexto de uma instituição particular

Este estudo objetiva analisar como os professores que atuam na formação inicial de novos professores desenvolvem o processo formativo para contribuir com a formação de novos docentes que estejam, preferencialmente, conectados com as demandas da docência na contemporaneidade. Para isso foi desenvolvida uma pesquisa qualitativa descritiva, da qual participaram dez docentes que atuam num curso de Licenciatura. Ao realizar a análise dos dados, destacaram-se cinco temáticas, a saber: a influência que a trajetória profissional exerce sobre a docência; perfil de formação profissional; intencionalidades didático-pedagógicas, ou o enfoque e direcionamento conferidos pelos professores ao ensino; as reflexões buscando crescimento e aprimoramento profissional; e, a concepção do que vem a ser um bom professor para atuar na formação inicial de futuros professores. Concluímos que um movimento formativo qualificado está articulado com o desenvolvimento de interações dialógicas e plurais de aprendizagens, perspectiva esta que exige uma disposição para aprender a ser docente e requer um processo de reflexão constante, tanto dos professores que atuam na formação inicial, quanto dos acadêmicos em formação. Neste movimento reflexivo entre professores e futuros professores é oportunizado o desenvolvimento de um processo formativo pautado pelas demandas da docência na contemporaneidade.

Sustainability in fashion

A reflexive movement around the universe of fashion shows alternatives to combat unrestrained consumption. The weakening of textile resources found in nature, and the devaluation of local production, seeking significantly, attributes that are applicable amid problematization caused since obtaining products. fashion items until their disposal. The slow fashion movement appears as a counterpoint to the fast-fashion model, seeking to add value in a rational way to clothing items in the globalized market, inserting sustainability as the main propagator of this dynamic that grows in a dizzying way over time. Thus, the objective of this research is to identify how slow fashion has been discussed in academic research. For this, a systematic literature search was carried from its first publication, in 2008, until the year 2019. The research is classified as descriptive with a qualitative-quantitative approach. As a result, 105 papers were obtained, ranging from articles in journals and congresses to master's thesis and doctoral dissertations. It is a review of literature on how this topic is being disseminated amid the informational flow of fashion and its easy democratic access and debate, as well as the systematization of data that prove its existence and its interfaces that are relevant in business competitive level. About the results, we identified mostly qualitative research, focusing on the conceptual development of the area until at least mid-2017, with a change to practice during the year 2019, with exponential growth in recent years, especially in countries like Brazil and United States. It was also possible to define the term movement to characterize slow fashion, as well as to determine a holistic concept that better defines the vision of researchers in the area, with special focus on the works of Kate Fletcher. With this review, the necessary knowledge is exposed to deal with the subject in question and expand this theme in other areas that are appropriate to it.

Vertical vision problem assessment in patients with Parkinson's disease

Background: Parkinson's disease (PD) is associated with a range of visual signs and symptoms, including defects in visual acuity, colour vision, the blink reflex, pupil reactivity, saccadic and smooth pursuit movements and visual evoked potentials It is achieved through complex reflexes: tracking, optokinetic nystagmus (OKN), vestibulo-ocular reflexes, saccades, etc.

Eclipse time variations in the post-common envelope binary V470 Cam

ABSTRACT Linear or quadratic relations fitted to the time-dependence of post-common envelope binary eclipse times generally give residuals exhibiting a cyclic variation. Among several possible explanations is the presence of one or more orbiting circumbinary objects causing a reflex motion of the binary centre-of-mass, thereby altering the light-travel-time.Twenty new eclipse times for the post-common envelope binary V470 Cam have been obtained; with these and 380 useable eclipse times in the literature, two circumbinary brown dwarfs having orbital periods of 7.87 ± 0.08 and 13.27 ± 0.16 yr were found to give an excellent fit to cyclic residuals resulting from a quadratic ephemeris fit. Irrespective of the excellent fit, it would be premature to claim that the V470 Cam binary is accompanied by two orbiting brown dwarfs; at the very least more eclipse times are needed to confirm the result and other plausible explanations, such as the Applegate mechanism, need eliminating.

Documentação Narrativa de Experiências Pedagógicas. Saberes docentes do Ensino Médio rural a partir da realidade da escola.

Este texto, parte de pesquisa de doutorado, objetiva refletir acerca dos caminhos da experiência-formação desenvolvidos por meio da Documentação Narrativa de Experiências Pedagógicas com professores (as) do Ensino Médio Rural, etapa final da Educação Básica. A pesquisa foi realizada em uma escola rural do município de Juazeiro, interior da Bahia, e contou com sete colaboradores na produção de documentos narrativos pedagógicos. Neste texto discutimos o desenvolvimento do dispositivo da Documentação Narrativa de Experiências Pedagógicas em um movimento reflexivo quanto à sua produção como documento narrativo, se constitui como dispositivo epistemológico-político-metodológico que sustentou a pesquisa. Acreditamos que a inclusão da Documentação Narrativa de Experiências Pedagógicas possibilitou acessarmos esse lugar da pesquisa, não apenas a identificação de elementos que validam os debates em torno do problema de pesquisa constituído, mas encontrar de forma dialogada com os professores colaboradores do estudo, entendimentos no processo que apontam para a elaboração de outros sentidos em direção de uma “política de conhecimento”. Constrói-se, deste modo, a autonomia e autoria docente acerca de seus saberes.&#x0D; Palavras-chave: Documentação Narrativa de Experiências Pedagógicas; Experiência; Ensino Médio Rural; Autoria docente; Saberes.

Modelling shows that stimulation of the semicircular canals depends on the rotation centre

The vestibular system in the inner ear senses head movements, which is indispensable for balance during locomotion. The semicircular canals of the vestibular system are stimulated during head rotations, due to the interplay between its endolymph fluid and its cupula membrane. Until now, it has been assumed that the stimulation of the canals is independent of the rotation centre. However, Fluid-Structure Interaction investigation now shows that the horizontal canal is more strongly stimulated when the rotation centre lies further from the canal. Such eccentric rotations result in a different stimulation of the left and the right canal, because the distance to the rotation centre differs between both ears. The dissimilar stimulation enables localization of the rotation centre based on information from the canals alone, similar to sound localization based on the interaural time difference for hearing. Additionally, a rotation centre further away from the canal will probably elicit a larger reflexive eye movement. This is exactly what is required to compensate the larger change in viewing angle, and it corresponds to experimental findings. Two fictitious forces (d'Alembert forces), the centrifugal force and the Euler force, cause the rotation centre-dependency of the canal stimulation. Implications for (pre)clinical eccentric rotation experiments are discussed.

High-resolution transmission spectroscopy of MASCARA-2 b with EXPRES

We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a highly stabilized optical echelle spectrograph, designed to detect stellar reflex motions with amplitudes down to 30 cm s−1, and has recently been deployed at the Lowell Discovery Telescope. By analyzing the transmission spectrum of the ultra-hot Jupiter MASCARA-2 b using the cross-correlation method, we confirm previous detections of Fe I, Fe II, and Na I, which likely originate in the upper regions of the inflated atmosphere. In addition, we report significant detections of Mg I and Cr II. The absorption strengths change slightly with time, possibly indicating different temperatures and chemistry in the day- and nightside terminators. Using the effective stellar line-shape variation induced by the transiting planet, we constrain the projected spin-orbit misalignment of the system to 1.6 ± 3.1 degrees, consistent with an aligned orbit. We demonstrate that EXPRES joins a suite of instruments capable of phase-resolved spectroscopy of exoplanet atmospheres.

Virtual Reality as Distraction Analgesia for Office-Based Procedures: A Randomized Crossover-Controlled Trial.

The purpose of this study was to explore the use of immersive and interactive virtual reality (VR) for analgesia, anxiety reduction, and overall satisfaction in patients undergoing outpatient postoperative debridements. Randomized crossover-controlled trial. Academic outpatient clinic. Adult patients who had functional endoscopic sinus surgery and skull base surgery and were undergoing office-based postoperative nasal endoscopy and debridement were recruited and followed for 2 consecutive office visits. Participants were randomized to receive either the control or experimental analgesia for the first postoperative visit (PO1) and crossed over into the opposite treatment arm during the second postoperative visit (PO2). Outcomes included procedural pain, anxiety and satisfaction scores, procedural time, and reflexive head movements per minute (RHM). Eighty-two participants were recruited. At PO1, 39 received standard analgesia, and 43 received an immersive VR experience. At PO1, the VR group experienced significantly less anxiety (P = .043) and fewer RHM (P = .00016) than the control group. At PO2, the VR group experienced significantly fewer RHM (P = .0002). At PO2, patients who received the experimental treatment after initially receiving the control treatment had significantly decreased pain, anxiety, and RHM. This effect was not seen in the second group. Overall, 69.51% of patients felt that the VR treatment was better; 19.51% thought that it was the same; and 9.76% found it to be worse. VR technology holds promise as a nonpharmacologic analgesic and anxiolytic intervention for otolaryngology office-based procedures. Further study of VR use in other procedures is warranted. 1, randomized controlled trial.

A significant mutual inclination between the planets within the π Mensae system

Context. Measuring the geometry of multi-planet extrasolar systems can provide insight into their dynamical history and the processes of planetary formation. These types of measurements are challenging for systems that are detected through indirect techniques such as radial velocity and transit, having only been measured for a handful of systems to date. Aims. We aim to place constraints on the orbital geometry of the outer planet in the π Mensae system, a G0V star at a distance of 18.3 pc that is host to a wide-orbit super-Jovian (M sin i = 10.02 ± 0.15MJup) with a 5.7-yr period and an inner transiting super-Earth (M = 4.82 ± 0.85M⊕) with a 6.3-d period. Methods. The reflex motion induced by the outer planet on the π Mensae star causes a significant motion of the photocenter of the system on the sky plane over the course of the 5.7-year orbital period of the planet. We combined astrometric measurements from the HIPPARCOS and Gaia satellites with a precisely determined spectroscopic orbit in an attempt to measure this reflex motion, and in turn we constrained the inclination of the orbital plane of the outer planet. Results. We measure an inclination of ib = 49.9−4.5+5.3 deg for the orbital plane of π Mensae b, leading to a direct measurement of its mass of 13.01−0.95+1.03 MJup. We find a significant mutual inclination between the orbital planes of the two planets, with a 95% credible interval for imut of between 34.°5 and 140.°6 after accounting for the unknown position angle of the orbit of π Mensae c, strongly excluding a co-planar scenario for the two planets within this system. All orbits are stable in the present-day configuration, and secular oscillations of planet c’s eccentricity are quenched by general relativistic precession. Planet c may have undergone high eccentricity tidal migration triggered by Kozai-Lidov cycles, but dynamical histories involving disk migration or in situ formation are not ruled out. Nonetheless, this system provides the first piece of direct evidence that giant planets with large mutual inclinations have a role to play in the origins and evolution of some super-Earth systems.

The Hα Emission Line Variations of HR 6819

Abstract The star system HR 6819 was recently proposed by Rivinius et al. as the site of the nearest example of a stellar-mass black hole. Their spectra show evidence of two components: a B3 III star in a 40 day orbit and a stationary B-emission line star. Based upon the orbital mass function and the lack of evidence of a spectral component with reflex orbital motion, Rivinius et al. suggested that HR 6819 is a triple system consisting of an inner B3 III star plus black hole binary orbited by a distant Be star. Here we present an alternative model based upon an examination of the Hα emission line in their spectra. We show that the emission line displays the small reflex motion expected for the companion in the inner orbit and shows variations in profile shape related to orbital phase. This indicates that HR 6819 is a binary system consisting of a massive Be star and a low-mass companion that is the stripped down remnant of a former mass donor star in a mass transfer binary.

Deflection of the hypervelocity stars by the pull of the Large Magellanic Cloud on the Milky Way

ABSTRACT Stars slingshotted by the supermassive black hole at the Galactic Centre escape from the Milky Way so quickly that their trajectories are almost straight lines. Previous works have shown how these ‘hypervelocity stars’ (stars moving faster than the local Galactic escape speed) are subsequently deflected by the gravitational field of the Milky Way and the Large Magellanic Cloud (LMC), but have neglected to account for the reflex motion of the Milky Way in response to the fly-by of the LMC. A consequence of this motion is that the hypervelocity stars we see in the outskirts of the Milky Way today were ejected from where the Milky Way centre was hundreds of millions of years ago. This change in perspective causes large apparent deflections of several degrees in the trajectories of the hypervelocity stars. We quantify these deflections by simulating the ejection of hypervelocity stars from an isolated Milky Way (with a spherical or flattened dark matter halo), from a fixed-in-place Milky Way with a passing LMC, and from a Milky Way that responds to the passage of the LMC, finding that LMC passage causes larger deflections than can be caused by a flattened Galactic dark matter halo in ΛCDM. The $10\, \mu \mathrm{as}\, \mathrm{yr}^{-1}$ proper motion precision necessary to measure these deflections will be possible with the combination of Gaia with the proposed GaiaNIR successor mission, and these measurements will directly probe the shape of the Milky Way, the mass of the LMC, and the dance of these two galaxies.

Kinematic analysis of the method increasing the accuracy of treatment of conic surfaces

A method for processing high-precision conical surfaces under conditions of free grinding on a lever machine is proposed, which allows adjusting the process parameters taking into account the technological heredity of the workpiece from the point of view of the distribution pattern of the allowance to be removed from its surface. The scheme of implementation of the method in which the main links are a tool in the form of a faceplate and a separator for maintaining the required accuracy of its flatness. In order to develop a method of targeted control of the actuation of the working surface of the tool to maintain the required accuracy of its flatness, mathematical modeling of the motion patterns of the links of the actuator of the base machine, on which the proposed device for processing conical parts is installed, was performed. In the process of mathematical simulation structural analysis of the executive mechanism of the lever machine is carried out, connection between the generalized coordinate and provisions of links of the executive mechanism of the lever machine is established, position of the lever and the upper link in the vertical plane is probed, geometrical parameters of reflexive rotational motion of the upper link are considered, the ratio for calculation of length of a crank of the executive mechanism of the machine depending on amplitude of figurative movement of its output link is obtained. An analytical relationship has been established between the input and output links of the machine actuator, which makes it possible to calculate the length of the first of the marked links depending on the required amplitude of the oscillatory motion of the second of them and creates the prerequisites for the development of engineering methods for controlling the process of forming high-precision conical surfaces under conditions of free grinding.

Controlling motor neurons of every muscle for fly proboscis reaching.

We describe the anatomy of all the primary motor neurons in the fly proboscis and characterize their contributions to its diverse reaching movements. Pairing this behavior with the wealth of Drosophila's genetic tools offers the possibility to study motor control at single-neuron resolution, and soon throughout entire circuits. As an entry to these circuits, we provide detailed anatomy of proboscis motor neurons, muscles, and joints. We create a collection of fly strains to individually manipulate every proboscis muscle through control of its motor neurons, the first such collection for an appendage. We generate a model of the action of each proboscis joint, and find that only a small number of motor neurons are needed to produce proboscis reaching. Comprehensive control of each motor element in this numerically simple system paves the way for future study of both reflexive and flexible movements of this appendage.

Time Course of Sensory Substitution for Gravity Sensing in Visual Vertical Orientation Perception following Complete Vestibular Loss.

Loss of vestibular function causes severe acute symptoms of dizziness and disorientation, yet the brain can adapt and regain near to normal locomotor and orientation function through sensory substitution. Animal studies quantifying functional recovery have yet been limited to reflexive eye movements. Here, we studied the interplay between vestibular and proprioceptive graviception in macaque monkeys trained in an earth-vertical visual orientation (subjective visual vertical; SVV) task and measured the time course of sensory substitution for gravity perception following complete bilateral vestibular loss (BVL). Graviceptive gain, defined as the ratio of perceived versus actual tilt angle, decreased to 20% immediately following labyrinthectomy, and recovered to nearly prelesion levels with a time constant of approximately three weeks of postsurgery testing. We conclude that proprioception accounts for up to 20% of gravity sensing in normal animals, and is re-weighted to substitute completely perceptual graviception after vestibular loss. We show that these results can be accounted for by an optimal sensory fusion model.

A newer approach for quantitative assessment of patellar tendon reflex response using biomechanical data of foot movement by a digital method

Summary Background Assessment of deep tendon reflexes such as patellar tendon reflex (PTR) is the vital diagnostic procedure executed routinely by clinicians which can provide valuable information about the reflex arc. Despite common acceptance, the reflex rating scales remain subjective and qualitative, creating an opportunity for the development of objective measures to improve the reliability and efficacy of these clinical tools. Material and methods The proposed study presents with reflex quantification system for knee jerk response using electrogoniometer and accelerometer. These sensors are capable of detecting dynamic changes occurring in the movement of an object and they can convert biomechanical information of movement into digital signals. The proposed system utilizes this technology to assess knee jerk response and provide quantitative data on various aspects of the knee jerk. Results The dynamic action of the leg during knee jerk response created movement patterns which were captured by the utilization of the data acquisition system. Based on the reflex response of the leg, the frequency of analog signals from biomechanical sensors as well as the amplitude of the graph was changed. Components of knee jerk response such as Reflex Movement latency (RL), Jerk time (JT), Total reflex response time (TRT) and Reflex amplitude was recorded from the data obtained. Conclusion This study presents the method of patellar tendon reflex response measuring system based on computational data acquisition system using wearable sensors. This methodology can be used as a additional tool in clinical assessment of deep tendon reflexes. The main advantages of the proposed system are its portability, user-friendly and non-invasive nature.

Wrongful Omission as a Condition for Tort Liabilities

Abstract As omission of a person is a certain manifestation of his/her internal will from outside. Exactly through inactivity, the internal will of a person materializes due to which a person becomes a participant of public relations. At the same time in the absence of external expression of will inactivity of a person can not cause the occurrence of legal consequences, in particular, to be examined as a reason of origin of tort liabilities. If a person enacted because of negligence or poor awareness, it should be defined: whether a person knew or had to know about the necessity to perform a certain action. Accordingly, if a person possessed such knowledge this form of behavior will be treated as guilty omission, if not – this is an example of innocent omission. Responsibility for illegal omission can arise only when appropriate persons are included in the system of civil and legal relationships, thus are the subjects of civil relations. Damage caused by “reflexive movements” testifies the carelessness of a person to his/her behavior, which reflects his/her will. Therefore, such behavior of a person is considered to be wrongful.

A novel optical non-intrusive method for measuring acoustic startle reflex in humans

Objective: The development of a new non-intrusive optical system for remotely measuring acoustic startle reflex (ASR) in humans. Approach: The eye reflex movement during an acoustic stimulation session is recorded through a high-speed digital camera. The eyes region is isolated by the rest of the face by an advanced pyramid-like feature detection algorithm, which greatly reduces the number of false positives. A separate Lucas–Kanade optical flow routine is designed for the eyeblink movement detection and the startle eyeblink reflex (SEBR) curve extraction. Image masking is implemented for the elimination of unwanted artifacts caused mainly by voluntary eye movement. The proposed system was tested along with a valid EMG system on a sample of 32 healthy randomly selected adults, and the results were compared in order to measure the system’s degree of reliability. Main results: To assess the proposed method’s validity the EMG data was used as a benchmark. The results showed strong correlation between EMG and Camera acquired results, which proves the validity of the proposed method. Furthermore, by comparing the response probability and the signal to noise ratio (SNR) for the two techniques, we proved that the proposed method can surpass the traditional EMG system in terms of accuracy and reliability. Significance: The proposed technique presents a simple, robust and reliable non-intrusive means of measuring ASR in humans, with the potential of future implementation on various ASR psychophysiology experiments, such as the study of PPI.

EXPERIÊNCIA E (DES)IDENTIFICAÇÃO NO ENFRENTAMENTO DE DESIGUALDADES E PRECONCEITOS NA PERCEPÇÃO DOS AGENTES COMUNITÁRIOS DE SAÚDE

Este artigo discute tematizações sobre o preconceito no discurso de trabalhadores da saúde que cursaram o Projeto Caminhos do Cuidado, identificando efeitos que colaboraram para a superação destas relações com relação a usuários de álcool e outras drogas. Utilizamos metodologia qualitativa, com análise de conteúdo. A análise se baseou em dados provenientes de 78 rodas de conversa e 39 registros etnográficos, ocorridas nas 27 Unidades Federativas do Brasil. Os dados descrevem movimentos reflexivos dos trabalhadores que possibilitaram o enquadramento de relações identitárias para além de crivos morais e da essencialização dos sujeitos. Nossos resultados apontam a importância da experiência para a desconstrução de estereótipos e preconceitos, por produzir processos de desidentificação necessários para a superação de preconceitos. Destaca-se a importância do Agente Comunitário de Saúde, como o profissional estratégico para o trabalho com a temática do preconceito nos territórios.&#x0D; Palavras-chave: Desigualdade; Preconceito; Atenção Básica; Intervenção Psicossocial; Agentes Comunitários de Saúde;