Sample records for single-lens reflex dslr

  1. DSLR Double Star Astrometry Using an Alt-Az Telescope (United States)

    Frey, Thomas; Haworth, David


    The goal of this project was to determine if the double star's angular separation and position angle measurements could be successfully measured with a motor driven, alt-azimuth Dobsonian-mounted Newtonian telescope (without a field rotator), and a digital single-lens reflex (DSLR) camera. Additionally, the project was constrained by using as much existing equipment as much as possible, including an Apple MacBook Pro laptop and a Canon T2i camera. This project was additionally challenging because the first author had no experience with astrophotography.

  2. Temperature characterization of a radiating gas layer using digital-single-lens-reflex-camera-based two-color ratio pyrometry. (United States)

    Deep, Sneh; Krishna, Yedhu; Jagadeesh, Gopalan


    The two-color ratio pyrometry technique using a digital single-lens reflex camera has been used to measure the time-averaged and path-integrated temperature distribution in the radiating shock layer in a high-enthalpy flow. A 70 mm diameter cylindrical body with a 70 mm long spike was placed in a hypersonic shock tunnel, and the region behind the shock layer was investigated. The systematic error due to contributions from line emissions was corrected by monitoring the emission spectrum from this region using a spectrometer. The relative contributions due to line emissions on R, G, and B channels of the camera were 7.4%, 2.2%, and 0.4%, respectively. The temperature contours obtained clearly distinguished regions of highest temperature. The maximum absolute temperature obtained in the experiment was ∼2920  K±55  K, which was 20% lower than the stagnation temperature. This lower value is expected due to line-of-sight integration, time averaging, and losses in the flow. Strategies to overcome these limitations are also suggested in the paper.

  3. Decision Support System to Choose Digital Single Lens Camera with Simple Additive Weighting Method

    Directory of Open Access Journals (Sweden)

    Tri Pina Putri


    Full Text Available One of the technologies that evolve today is Digital Single Lens Reflex (DSLR camera. The number of products makes users have difficulties to choose the appropriate camera based on their criteria. Users may utilize several ways to help them choosing the intended camera such as using magazine, internet, and other media. This paper discusses about a web based decision support system to choose cameras by using SAW (Simple Additive Weighting method in order to make the decision process more effective and efficient. This system is expected to give recommendations about the camera which is appropriate with the user’s need and criteria based on the cost, the resolution, the feature, the ISO, and the censor. The system was implemented by using PHP and MySQL. Based on the result of questionnaire distributed to 20 respondents, 60% respondents agree that this decision support system can help users to choose the appropriate camera DSLR in accordance with the user’s need, 60% of respondents agree that this decision support system is more effective to choose DSLR camera and 75% of respondents agree that this system is more efficient. In addition, 60.55% of respondents agree that this system has met 5 Es Usability Framework.

  4. A practical application of photogrammetry to performing rib characterization measurements in an underground coal mine using a DSLR camera. (United States)

    Slaker, Brent A; Mohamed, Khaled M


    Understanding coal mine rib behavior is important for inferring pillar loading conditions as well as ensuring the safety of miners who are regularly exposed to ribs. Due to the variability in the geometry of underground openings and ground behavior, point measurements often fail to capture the true movement of mine workings. Photogrammetry is a potentially fast, cheap, and precise supplemental measurement tool in comparison to extensometers, tape measures, or laser range meters, but its application in underground coal has been limited. The practical use of photogrammetry was tested at the Safety Research Coal Mine, National Institute for Occupational Safety and Health (NIOSH). A commercially available, digital single-lens reflex (DSLR) camera was used to perform the photogrammetric surveys for the experiment. Several experiments were performed using different lighting conditions, distances to subject, camera settings, and photograph overlaps, with results summarized as follows: the lighting method was found to be insignificant if the scene was appropriately illuminated. It was found that the distance to the subject has a minimal impact on result accuracy, and that camera settings have a significant impact on the photogrammetric quality of images. An increasing photograph resolution was preferable when measuring plane orientations; otherwise a high point cloud density would likely be excessive. Focal ratio (F-stop) changes affect the depth of field and image quality in situations where multiple angles are necessary to survey cleat orientations. Photograph overlap is very important to proper three-dimensional reconstruction, and at least 60% overlap between photograph pairs is ideal to avoid unnecessary post-processing. The suggestions and guidelines proposed are designed to increase the quality of photogrammetry inputs and outputs as well as minimize processing time, and serve as a starting point for an underground coal photogrammetry study.

  5. Using DSLR cameras in digital holography (United States)

    Hincapié-Zuluaga, Diego; Herrera-Ramírez, Jorge; García-Sucerquia, Jorge


    In Digital Holography (DH), the size of the bidimensional image sensor to record the digital hologram, plays a key role on the performance of this imaging technique; the larger the size of the camera sensor, the better the quality of the final reconstructed image. Scientific cameras with large formats are offered in the market, but their cost and availability limit their use as a first option when implementing DH. Nowadays, DSLR cameras provide an easy-access alternative that is worthwhile to be explored. The DSLR cameras are a wide, commercial, and available option that in comparison with traditional scientific cameras, offer a much lower cost per effective pixel over a large sensing area. However, in the DSLR cameras, with their RGB pixel distribution, the sampling of information is different to the sampling in monochrome cameras usually employed in DH. This fact has implications in their performance. In this work, we discuss why DSLR cameras are not extensively used for DH, taking into account the problem reported by different authors of object replication. Simulations of DH using monochromatic and DSLR cameras are presented and a theoretical deduction for the replication problem using the Fourier theory is also shown. Experimental results of DH implementation using a DSLR camera show the replication problem.

  6. Margin Reflex Distance: Differences Based on Camera and Flash Positions. (United States)

    Choi, Catherine J; Chou, Jonathan C; Lefebvre, Daniel R; Yoon, Michael K


    To evaluate the effect of camera flash position on the measurement of photographic margin reflex distances (MRD). Subjects without any ophthalmic disease were prospectively enrolled after institutional review board approval. Clinical measurements of MRD1 and interpalpebral fissure were obtained. Photographs were then taken with a digital single lens reflex with built-in pop-up flash (dSLR-pop), a dSLR with lens-mounted ring flash (dSLR-ring), a point-and-shoot camera, and a smartphone, each in 4 positions: with the camera upright, rotated 90°, 180°, and 270°. The images were analyzed using ImageJ software to measure MRD1, interpalpebral fissure, horizontal white-to-white, and distance from nasal limbus to the corneal light reflex. Thirty-two eyes of 16 subjects were included (ages 27-65). When using the dSLR-ring, point-and-shoot, and smartphone, the difference between clinical and photographic MRD1 did not reach statistical significance. There was, however, a statistically significant difference in the upright position with dSLR-pop (mean difference 0.703 mm, σ = 0.984 mm, p = 0.0008). For dSLR-pop, photographic MRD1 in upright versus inverted position differed significantly (mean difference -0.562 mm, σ =0.348 mm, p MRD1 between dSLR-pop and dSLR-ring showed significant difference in upright position (mean difference -0.572 mm, σ = 0.701 mm, p = 0.0002). There were no statistically significant differences between clinical and photographic interpalpebral fissure, and among white-to-white and nasal limbus to light reflex measurements in any position in all 4 cameras. When using photographs for measurement of MRD1, cameras with a near-coaxial light source and aperture have values that are most similar to clinical measurements.

  7. Budget astrophotography imaging with your DSLR or webcam

    CERN Document Server

    Jensen, Timothy J


    Here are clear explanations of how to make superb astronomical deep-sky images using only a DSLR or webcam and an astronomical telescope – no expensive dedicated CCD cameras needed! The book is written for amateur astronomers interested in budget astrophotography – the deep sky, not just the Moon and planets – and for those who want to improve their imaging skills using DSLR and webcams. It is even possible to use existing (non-specialist astronomical) equipment for scientific applications such as high resolution planetary and lunar photography, astrometry, photometry, and spectroscopy. The introduction of the CCD revolutionized astrophotography. The availability of this technology to the amateur astronomy community has allowed advanced science and imaging techniques to become available to almost anyone willing to take the time to learn a few, simple techniques. Specialized cooled-chip CCD imagers are capable of superb results in the right hands – but they are all very expensive. If budget is import...

  8. Photographic zoom fisheye lens design for DSLR cameras (United States)

    Yan, Yufeng; Sasian, Jose


    Photographic fisheye lenses with fixed focal length for cameras with different sensor formats have been well developed for decades. However, photographic fisheye lenses with variable focal length are rare on the market due in part to the greater design difficulty. This paper presents a large aperture zoom fisheye lens for DSLR cameras that produces both circular and diagonal fisheye imaging for 35-mm sensors and diagonal fisheye imaging for APS-C sensors. The history and optical characteristics of fisheye lenses are briefly reviewed. Then, a 9.2- to 16.1-mm F/2.8 to F/3.5 zoom fisheye lens design is presented, including the design approach and aberration control. Image quality and tolerance performance analysis for this lens are also presented.

  9. Infant reflexes (United States)

    ... twitch their hips toward the touch in a dancing movement. GRASP REFLEX This reflex occurs if you ... Infant reflexes can occur in adults who have: Brain damage Stroke When to Contact a Medical Professional ...

  10. Single lens photometric machine vision with 3D imaging for fiber-to-chip coupling. (United States)

    Liu, Xu; Hu, Hongmei; Sun, Xiaohan


    A single lens photometric machine vision (SLPMV) optical microbench is presented and built for fiber-to-chip coupling. By a rotation mechanics in SLPMV, the multi-view-camera can scan the various surface status of the chips coupled. To realize 3D imaging more explicitly, the modified photometric stereo algorithm is proposed through acquiring the images of weak saturation, matching the scanning illuminative angles, and rectifying rectangularly the original images. The reconstructed images have had similar qualities as those obtained by scanning electron microscopy and have unveiled the detailed information obscured in the 2D images. For the InP-based optical waveguide chip coupled with wedge-shaped fiber, the insertion loss tested on the SLPMV is 3 dB less than one on the conventional testing station. The SLPMV could serve as a more cost-effective and compact scientific observation instrumentation in imaging informatics than commercial ones.

  11. A new self-made digital slide scanner and microscope for imaging and quantification of fluorescent microspheres

    DEFF Research Database (Denmark)

    Henning, William; Bjerglund Andersen, Julie; Højgaard, Liselotte


    Objective: A low-cost microscope slide scanner was constructed for the purpose of digital imaging of newborn piglet brain tissue and to quantify fluorescent microspheres in tissue. Methods: Using a standard digital single-lens reflex (DSLR) camera, fluorescent imaging of newborn piglet brain tiss...

  12. Reflexives and reflexive constructions in Afrikaans

    African Journals Online (AJOL)

    Kate H

    2. Reflexives. Afrikaans items belonging to the traditional lexical category of reflexives (or reflexive ... reflexive and non-reflexive pronouns are syntactically derived from the same lexical root pronoun √PRON. The ...... 32 The matrix verbs in (33) and (34) both concern a future activity of an entity: belowe (“promise”) in the (a).

  13. Use and validation of mirrorless digital single light reflex camera for recording of vitreoretinal surgeries in high definition

    Directory of Open Access Journals (Sweden)

    Sumeet Khanduja


    Full Text Available Purpose: The purpose of this study is to describe the use of commercial digital single light reflex (DSLR for vitreoretinal surgery recording and compare it to standard 3-chip charged coupling device (CCD camera. Methods: Simultaneous recording was done using Sony A7s2 camera and Sony high-definition 3-chip camera attached to each side of the microscope. The videos recorded from both the camera systems were edited and sequences of similar time frames were selected. Three sequences that selected for evaluation were (a anterior segment surgery, (b surgery under direct viewing system, and (c surgery under indirect wide-angle viewing system. The videos of each sequence were evaluated and rated on a scale of 0-10 for color, contrast, and overall quality Results: Most results were rated either 8/10 or 9/10 for both the cameras. A noninferiority analysis by comparing mean scores of DSLR camera versus CCD camera was performed and P values were obtained. The mean scores of the two cameras were comparable for each other on all parameters assessed in the different videos except of color and contrast in posterior pole view and color on wide-angle view, which were rated significantly higher (better in DSLR camera. Conclusion: Commercial DSLRs are an affordable low-cost alternative for vitreoretinal surgery recording and may be used for documentation and teaching.

  14. The Light Field Attachment: Turning a DSLR into a Light Field Camera Using a Low Budget Camera Ring. (United States)

    Wang, Yuwang; Liu, Yebin; Heidrich, Wolfgang; Dai, Qionghai


    We propose a concept for a lens attachment that turns a standard DSLR camera and lens into a light field camera. The attachment consists of eight low-resolution, low-quality side cameras arranged around the central high-quality SLR lens. Unlike most existing light field camera architectures, this design provides a high-quality 2D image mode, while simultaneously enabling a new high-quality light field mode with a large camera baseline but little added weight, cost, or bulk compared with the base DSLR camera. From an algorithmic point of view, the high-quality light field mode is made possible by a new light field super-resolution method that first improves the spatial resolution and image quality of the side cameras and then interpolates additional views as needed. At the heart of this process is a super-resolution method that we call iterative Patch- And Depth-based Synthesis (iPADS), which combines patch-based and depth-based synthesis in a novel fashion. Experimental results obtained for both real captured data and synthetic data confirm that our method achieves substantial improvements in super-resolution for side-view images as well as the high-quality and view-coherent rendering of dense and high-resolution light fields.

  15. How to make a small phone camera shoot like a big DSLR: creating and fusing multi-modal exposure series (United States)

    Binder, Thomas; Kriener, Florian; Wichner, Christian; Wille, Manuel; Wellner, Mike; Kaester, Thomas; Martinetz, Thomas; Barth, Erhardt


    The present work aims at improving the image quality of low-cost cameras based on multiple exposures, machine learning, and a perceptual quality measure. The particular implementation consists of two cameras, one being a high-quality DSLR, the other part of a cell phone. The cameras are connected via USB. Since the system is designed to take many exposures of the same scene, a stable mechanical coupling of the cameras and the use of a tripod are required. Details on the following issues are presented: design aspects of the mechanical coupling of the cameras, camera control via FCam and the Picture Transfer Protocol (PTP), further aspects of the design of the control software, and post processing of the exposures from both cameras. The cell phone images are taken with different exposure times and different focus settings and are simultaneously fused. By using the DSLR image as a reference, the parameters of the fusion scheme are learned from examples and can be used to optimize the design of the cell phone. First results show that the depth of field can be extended, the dynamic range can be improved and the noise can be reduced.

  16. The Light Field Attachment: Turning a DSLR into a Light Field Camera Using a Low Budget Camera Ring

    KAUST Repository

    Wang, Yuwang


    We propose a concept for a lens attachment that turns a standard DSLR camera and lens into a light field camera. The attachment consists of 8 low-resolution, low-quality side cameras arranged around the central high-quality SLR lens. Unlike most existing light field camera architectures, this design provides a high-quality 2D image mode, while simultaneously enabling a new high-quality light field mode with a large camera baseline but little added weight, cost, or bulk compared with the base DSLR camera. From an algorithmic point of view, the high-quality light field mode is made possible by a new light field super-resolution method that first improves the spatial resolution and image quality of the side cameras and then interpolates additional views as needed. At the heart of this process is a super-resolution method that we call iterative Patch- And Depth-based Synthesis (iPADS), which combines patch-based and depth-based synthesis in a novel fashion. Experimental results obtained for both real captured data and synthetic data confirm that our method achieves substantial improvements in super-resolution for side-view images as well as the high-quality and view-coherent rendering of dense and high-resolution light fields.

  17. Preventing falls in older multifocal glasses wearers by providing single-lens distance glasses: the protocol for the VISIBLE randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Lee Bonsan B


    Full Text Available Abstract Background Recent research has shown that wearing multifocal glasses increases the risk of trips and falls in older people. The aim of this study is to determine whether the provision of single-lens distance glasses to older multifocal glasses wearers, with recommendations for wearing them for walking and outdoor activities, can prevent falls. We will also measure the effect of the intervention on health status, lifestyle activities and fear of falling, as well as the extent of adherence to the program. Methods/Design Approximately 580 older people who are regular wearers of multifocal glasses people will be recruited. Participants will be randomly allocated to either an intervention group (provision of single lens glasses, with counselling and advice about appropriate use or a control group (usual care. The primary outcome measure will be falls (measured with 13 monthly calendars. Secondary measures will be quality of life, falls efficacy, physical activity levels and adverse events. Discussions The study will determine the impact of providing single-lens glasses, with advice about appropriate use, on preventing falls in older regular wearers of multifocal glasses. This pragmatic intervention, if found to be effective, will guide practitioners with regard to recommending appropriate glasses for minimising the risk of falls in older people. Trial Registration The protocol for this study was registered with the Clinical Protocol Registration System on June 7th 2006 (#350855.

  18. Reflex sympathetic dystrophy. (United States)

    Miller, Ruth L S


    Reflex sympathetic dystrophy, also known as complex regional pain syndrome type I, is a multisymptom syndrome usually affecting one or more extremities. It is inadequately understood and, therefore, often frustrating to treat. This article presents a case study of a 23-year career nurse who developed reflex sympathetic dystrophy of the left knee. It also reviews the rationale for reflex sympathetic dystrophy, treatment, and life-care planning for a patient with reflex sympathetic dystrophy.

  19. Embodied Self-Reflexivity (United States)

    Pagis, Michal


    Drawing on G. H. Mead and Merleau-Ponty, this paper aims to extend our understanding of self-reflexivity beyond the notion of a discursive, abstract, and symbolic process. It offers a framework for embodied self-reflexivity, which anchors the self in the reflexive capacity of bodily sensations. The data consist of two years of ethnographic…

  20. Epidemiology of reflex syncope

    NARCIS (Netherlands)

    Colman, N.; Nahm, K.; Ganzeboom, K. S.; Shen, W. K.; Reitsma, J.; Linzer, M.; Wieling, W.; Kaufmann, H.


    Cost-effective diagnostic approaches to reflex syncope require knowledge of its frequency and causes in different age groups. For this purpose we reviewed the available literature dealing with the epidemiology of reflex syncope. The incidence pattern of reflex syncope in the general population and

  1. Reflexivity: Licensing or enforcing


    Schadler, D.


    During my research I looked at 117 languages and their anaphoric systems. The main goal of this study was to analyse reflexivization, its reasons and effects, by covering cross-linguistic data and by taking into account the variation we find on a macro- and micro-level. To be more precise, throughout this dissertation I investigated: whether we find indeed some special marking for reflexivity, i.e. licensing of reflexivity, across languages. whether there are complex reflexives that do not ha...

  2. Cruciate ligament reflexes

    DEFF Research Database (Denmark)

    Krogsgaard, M.R.; Dyhre-Poulsen, Poul; Fischer-Rasmussen, T.


    The idea of muscular reflexes elicited from sensory nerves of the cruciate ligaments is more than 100 years old, but the existence of such reflexes has not been proven until the recent two decades. First in animal experiments, a muscular excitation could be elicited in the hamstrings when the ant...

  3. Too Busy for Reflexivity?

    DEFF Research Database (Denmark)

    Ratner, Helene

    colleagues” (Lynch 2000:46). Some 20 years later, these debates still linger in the shadows with some anthropologists refer to their work as “postreflexive” (eg. Maurer 2005, Riles 2000). This suggests a need to move beyond reflexivity without leaving it entirely behind. While reflexivity today still...

  4. Etnography and Reflexivity

    Directory of Open Access Journals (Sweden)

    Mario Cardano


    Full Text Available This essay deals with a relevant and controversial topic – objectivity in ethnographic research. More specifically, I would like to examine how reflexive procedures, more precisely “reflexive account”, can increase the robustness of results gained through an ethnographic research. The essay is organized in five parts. I will start by giving a preliminary definition of the two key concepts which are at the center of the analysis – objectivity and reflexivity. I will then give a brief description of the epistemological framework in which the proposed conceptions of objectivity and reflexivity are located. Thirdly, I move on to consider the epistemic status of ethnographic research, and will emphasize that ethnographies are not just “theory-laden”, as many writers have stated, but also “praxis” or “procedure laden”. In other words, I will stress that it is not only theories which are inevitably embedded in research, influencing how observations can be made; much the same can also be said of the concrete research practices which contribute to determine the experience of the ethnographer and its representation in a text. Fourthly, I will discuss why it is useful to employ reflexive practices, and then immediately afterwards will illustrate the ways in which reflexive descriptions can contribute to greater objectivity of ethnographic accounts. In conclusion, I will discuss a number of objections which have been raised against this use of reflexivity.

  5. On Reflexive Data Models

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, S.


    An information system is reflexive if it stores a description of its current structure in the body of stored information and is acting on the base of this information. A data model is reflexive, if its language is meta-closed and can be used to build such a system. The need for reflexive data models in new areas of information technology applications is argued. An attempt to express basic notions related to information systems is made in the case when the system supports and uses meta-closed representation of the data.

  6. Single-lens 3D digital image correlation system based on a bilateral telecentric lens and a bi-prism: validation and application. (United States)

    Wu, Lifu; Zhu, Jianguo; Xie, Huimin


    By using the principle of stereovision, 3D digital image correlation (3D-DIC) can determine the 3D morphology and deformation of a target and has been widely used in experimental mechanics as a noncontact 3D measurement technique. To eliminate the limitations of the conventional 3D-DIC system, this study proposes a calibration-free single-lens 3D-DIC system based on a bilateral telecentric lens and a bi-prism. The performance of the proposed system is verified by tests of rigid-body translation along the out-of-plane direction. As a comparison, the same rigid-body translations are measured using a single-entocentric-lens 3D-DIC system. The results show that the measurement accuracy of the proposed system is higher than that of the entocentric-lens-based one. As an application, the proposed system is used to measure the thermal linear expansion of a ceramic plate at elevated temperatures. The reasonable measurement results verify its applicability in deformation measurements, even in high-temperature environments.

  7. Too Busy for Reflexivity?

    DEFF Research Database (Denmark)

    Ratner, Helene

    of a “corrosive relativism in which everything is but a more or less clever expression of opinion” (Geertz 1988:2, 3) and it has suffered the little flattering accusations of piling "layer upon layer of self-consciousness to no avail" (Latour 1988:170) with little “interest [for] … theoretically ambitious...... of reflexivity. Facing these challenges, the managers employ a pragmatic moral, which allows them to bracket or defer their epistemological ideal of reflexivity while keeping it alive as exactly that: a promise of a future settlement. The paper concludes by comparing academics’ and school managers’ versions...

  8. Reflexivity and social justice

    DEFF Research Database (Denmark)

    Maksimovic, Tijana; Jakobsen, Helle Nordentoft


    Career practitioners’ reflexive understanding of their professional role as change agents in career guidance and counselling practices has a major impact on how social justice can be achieved. This entitles an awareness of the way in which guidance and counselling practices are embedded in the co......Career practitioners’ reflexive understanding of their professional role as change agents in career guidance and counselling practices has a major impact on how social justice can be achieved. This entitles an awareness of the way in which guidance and counselling practices are embedded...

  9. Corneomandibular reflex: Anatomical basis

    Directory of Open Access Journals (Sweden)

    Michele Pistacchi


    Full Text Available Corneomandibular reflex is a pathological phenomenon evident in cases of severe brainstem damage. It is considered to be a pathological exteroceptive reflex, associated with precentro bulbar tract lesions. The sign is useful in distinguishing central neurological injuries to metabolic disorders in acutely comatose patients, localizing lesions to the upper brainstem area, determining the depth of coma and its evolution, providing evidence of uncal or transtentorial herniation in acute cerebral hemisphere lesions, and it is a marker of supraspinal level impairment in amyotrophic lateral sclerosis and multiple sclerosis. This sign was evident in a patient with severe brain damage. We discuss the literature findings and its relevance in prognosis establishment.

  10. Reflexivity in qualitative research

    DEFF Research Database (Denmark)

    Evans, Adam Brian; Nistrup, Anne; Henderson, Hannah


    practice, that is, to reflect on our own values, beliefs, and biographies. It can be difficult to know exactly how a researcher should engage in these practices, however. Here, we discuss our reflexive practice in two case studies, both which utilized the same figurational theoretical framework....... In Study 2, changes in study goals meant that retrospective reflexive practice was necessary, while the principal researcher had an established relationship with participants in the study, which made reflection on her perspective vital. We conclude by highlighting the importance of methodological...

  11. Reflexivity of Routines

    DEFF Research Database (Denmark)

    Yamauchi, Yutaka; Hiramoto, Takeshi


    This study reconsiders the meaning and implications of reflexivity for the theory of routines. Due to their mundane nature, routines tend to be considered unambiguous phenomena that everyone can readily understand. The performative theory of routines has challenged this view by suggesting there i...

  12. pyLIMA: An Open-source Package for Microlensing Modeling. I. Presentation of the Software and Analysis of Single-lens Models (United States)

    Bachelet, E.; Norbury, M.; Bozza, V.; Street, R.


    Microlensing is a unique tool, capable of detecting the “cold” planets between ˜1 and 10 au from their host stars and even unbound “free-floating” planets. This regime has been poorly sampled to date owing to the limitations of alternative planet-finding methods, but a watershed in discoveries is anticipated in the near future thanks to the planned microlensing surveys of WFIRST-AFTA and Euclid's Extended Mission. Of the many challenges inherent in these missions, the modeling of microlensing events will be of primary importance, yet it is often time-consuming, complex, and perceived as a daunting barrier to participation in the field. The large scale of future survey data products will require thorough but efficient modeling software, but, unlike other areas of exoplanet research, microlensing currently lacks a publicly available, well-documented package to conduct this type of analysis. We present version 1.0 of the python Lightcurve Identification and Microlensing Analysis (pyLIMA). This software is written in Python and uses existing packages as much as possible to make it widely accessible. In this paper, we describe the overall architecture of the software and the core modules for modeling single-lens events. To verify the performance of this software, we use it to model both real data sets from events published in the literature and generated test data produced using pyLIMA's simulation module. The results demonstrate that pyLIMA is an efficient tool for microlensing modeling. We will expand pyLIMA to consider more complex phenomena in the following papers.

  13. Reflex epilepsy: a review

    Directory of Open Access Journals (Sweden)

    Karim Nikkhah


    Full Text Available Interesting phenomena of reflex epileptic syndromes are characterized by epileptic seizures each one induced by specific stimulus with a variety of types. Simple triggers, which lead to seizures within seconds, are of sensory type (most commonly visual, most rarely tactile or proprioceptive stimuli. Complex triggers, which are mostly of cognitive type such as praxis, reading, talking, and music, usually induce the epileptic event within minutes. It should differ from what most epileptic patients report as provocative precipitants for seizures (such as emotional stress, fatigue, fever, sleep deprivation, alcohol, and menstrual cycle. The identification of a specific trigger is not only important for patients or their parents to avoid seizures, but also it might help neurologists to choose the most effective antiepileptic drug for each case. In addition, research in this area may possibly reveal some underlying pathophysiology of epileptic phenomena in the brain.In this review, we briefly introduce reported reflex epileptic seizures, their clinical features and management.

  14. Corporeal reflexivity and autism. (United States)

    Ochs, Elinor


    Ethnographic video recordings of high functioning children with autism or Aspergers Syndrome in everyday social encounters evidence their first person perspectives. High quality visual and audio data allow detailed analysis of children's bodies and talk as loci of reflexivity. Corporeal reflexivity involves displays of awareness of one's body as an experiencing subject and a physical object accessible to the gaze of others. Gaze, demeanor, actions, and sotto voce commentaries on unfolding situations indicate a range of moment-by-moment reflexive responses to social situations. Autism is associated with neurologically based motor problems (e.g. delayed action-goal coordination, clumsiness) and highly repetitive movements to self-soothe. These behaviors can provoke derision among classmates at school. Focusing on a 9-year-old girl's encounters with peers on the playground, this study documents precisely how autistic children can become enmeshed as unwitting objects of stigma and how they reflect upon their social rejection as it transpires. Children with autism spectrum disorders in laboratory settings manifest diminished understandings of social emotions such as embarrassment, as part of a more general impairment in social perspective-taking. Video ethnography, however, takes us further, into discovering autistic children's subjective sense of vulnerability to the gaze of classmates.

  15. Soleus stretch reflex during cycling

    DEFF Research Database (Denmark)

    Grey, Michael James; Pierce, C. W.; Milner, T. E.


    the crank cycle, producing ankle dorsiflexion perturbations of similar trajectory. The stretch reflex was greatest during the power phase of the crank cycle and was decreased to the level of background EMG during recovery. Matched perturbations were induced under static conditions at the same crank angle...... active cycling as has been shown with the H-reflex. This lack of depression may reflect a decreased susceptibility of the stretch reflex to inhibition, possibly originating from presynaptic mechanisms....

  16. Reflexive Dressing: Rethinking Retro

    Directory of Open Access Journals (Sweden)

    Stella North


    Full Text Available This article undertakes a philosophical exploration of the act we know, or think we know, as ‘dressing’. Inhabiting, in thought, the moment in which we dress, I examine some of its constituent mechanisms, attending to the impulses by which dressing is generated out of subjective experience.  When those impulses are temporally marked, as they are in the case of retro dress, this generation is a two-pronged process, in which the holding of the body in time, and the holding of time in the body, recalibrate one another. The process of ‘dressing,’ in this understanding, has a reflexivity which is double; it entails the turning of the body, with dress as medium, towards itself, and the turning of present experience towards some felt notion of the past. Reflexively dressing, we are always becoming ourselves, and becoming other than ourselves, at once; a movement of circuitous internalisation and externalisation by which the ambiguation inherent in material experience is realised.

  17. On orbit-reflexive operators

    Czech Academy of Sciences Publication Activity Database

    Müller, Vladimír; Vršovský, Jan


    Roč. 79, č. 2 (2009), s. 497-510 ISSN 0024-6107 Institutional research plan: CEZ:AV0Z10190503 Keywords : reflexive operators * orbit-reflexivity Subject RIV: BA - General Mathematics Impact factor: 0.798, year: 2009


    NARCIS (Netherlands)


    Reflex sympathetic dystrophy is a chronic pain syndrome characterized by chronic burning pain, restricted range of motion, oedema and vasolability. Patients are difficult to treat and the prognosis is very often poor. This report emphasizes that an amputation in case of a reflex sympathetic

  19. Nonpharmacological treatment of reflex syncope

    NARCIS (Netherlands)

    Wieling, Wouter; Colman, Nancy; Krediet, C. T. Paul; Freeman, Roy


    Reflex syncope is a common medical problem. Vasovagal reflex syncope is the most frequent form. Although the prognosis of the disorder is excellent, it may impose substantial changes in life style and cause profound psychological distress. Thus, management of this disorder is an important issue.

  20. [Reflex seizures, cinema and television]. (United States)

    Olivares-Romero, Jesús


    In movies and television series are few references to seizures or reflex epilepsy even though in real life are an important subgroup of total epileptic syndromes. It has performed a search on the topic, identified 25 films in which they appear reflex seizures. Most seizures observed are tonic-clonic and visual stimuli are the most numerous, corresponding all with flashing lights. The emotions are the main stimuli in higher level processes. In most cases it is not possible to know if a character suffers a reflex epilepsy or suffer reflex seizures in the context of another epileptic syndrome. The main conclusion is that, in the movies, the reflex seizures are merely a visual reinforcing and anecdotal element without significant influence on the plot.

  1. Reflex sympathetic dystrophy in hemiplegia. (United States)

    Gokkaya, Nilufer Kutay Ordu; Aras, Meltem; Yesiltepe, Elcin; Koseoglu, Fusun


    There is a high incidence of reflex sympathetic dystrophy of the upper limbs in patients with hemiplegia, and its painful and functional consequences present a problem to specialists in physical medicine and rehabilitation. This study was designed to assess the role of several factors in the occurrence of reflex sympathetic dystrophy in patients with hemiplegia. Ninety-five consecutive stroke patients (63 male and 32 female, mean age 59+/-12 years) admitted to our hospital were evaluated. Of the study group, 29 patients (30.5%) were found to develop reflex sympathetic dystrophy. There were no significant differences between the hemiplegic patient groups with or without reflex sympathetic dystrophy regarding age, gender, etiology, side of involvement, disease duration and the presence of comorbidities. The recovery stages of hemiplegia, as shown by Brunnstrom functional classification, were significantly different between the two groups; patients in lower recovery stages tended to develop reflex sympathetic dystrophy more frequently (Preflex sympathetic dystrophy. Glenohumeral subluxation was present in 37 patients (38.9%) in our study group and the presence of this complication was related to the occurrence of reflex sympathetic dystrophy. The presence of glenohumeral subluxation was significantly higher in patients with reflex sympathetic dystrophy (21/29, 72.4%) when compared to the patients without reflex sympathetic dystrophy (16/66, 24.2%) (Preflex sympathetic dystrophy. These results suggest that lower recovery stages, reduced tonus and glenohumeral subluxation significantly contribute to the occurrence of reflex sympathetic dystrophy in the hemiplegic patient. We believe that preventive and treatment measures should consider these factors as they seem to have in common a higher risk of traumatizing the paralyzed upper limb and causing reflex sympathetic dystrophy.

  2. Reflexivity and social justice

    DEFF Research Database (Denmark)

    Maksimovic, Tijana; Jakobsen, Helle Nordentoft


    in the complexity of causes of social injustice in their own environment – i.e. how these are perpetuated in the design and implementation of national and organisational policies and how they influence counselling relationships. A generic challenge in career guidance is, for instance, to help individuals follow......Career practitioners’ reflexive understanding of their professional role as change agents in career guidance and counselling practices has a major impact on how social justice can be achieved. This entitles an awareness of the way in which guidance and counselling practices are embedded....... In this chapter, we argue that career practitioners may perpetuate social inequalities by not reflecting on how they themselves potentially take part in the reproduction of dominant discourses when they navigate and handle these tensions. In particular, the dominance of neo-liberal discourse in institutional...

  3. Fulfill Your Digital Preservation Goals with a Budget Studio

    Directory of Open Access Journals (Sweden)

    Yongli Zhou


    Full Text Available In order to fulfill digital preservation goals, many institutions use high-end scanners for in-house scanning of historical print and oversize materials. However, high-end scanners’ prices do not fit in many small institutions’ budget. As digital single-lens reflex (DSLR camera technologies advance and camera prices drop quickly, a budget photography studio can help to achieve institutions’ preservation goals.  This paper compares images delivered by a high-end overhead scanner and a consumer level DSLR camera, discusses pros and cons of using each method, demonstrates how to set up a cost efficient shooting studio, and presents a budget estimate for a studio.

  4. Reflexivity in Narratives on Practice

    DEFF Research Database (Denmark)

    Jakobsen, Helle Nordentoft; Olesen, Lektor Birgitte Ravn

    Previous research has shown how reflexivity is a precondition for knowledge co-production through productive dialogue in organisational contexts because it entails a re-ordering, re-arranging and re-designing of what one knows and therefore creates new angles of vision. In this paper, we draw...... on Bakhtinian dialogic communication theory and discursive psychology to investigate the written practice narratives of 23 students on a Masters Degree Programme in Educational Studies, focusing on how the process of writing narratives accentuates reflexivity. Our findings indicate that the narratives invite...... have the potential to bring about productive learning in organizational contexts since they appear to stimulate participants’ relational engagement and reflexivity....

  5. Reflex Sympathetic Dystrophy in Children

    Directory of Open Access Journals (Sweden)

    Adnan Ayvaz


    Full Text Available    Reflex sympathetic dystrophy (chronic regional pain syndrome isn’t frequently encountered in practical pediatrics and childhood. Reflex sympathetic dystrophy syndrome (RSD is a disorder characterized by widespread localized pain, often along with swelling, discoloration, trophic changes and autonomic abnormalities such as vasomotor disorders. Its etio-pathogenesis hasn’t been completely determined.The disease can form in an area innerved by a partially damaged nerve and usually follows minor injury or trauma. In this paper, two girl patients with reflex sympathetic dystrophy are discussed along with the laboratory and clinic finding by accompaniment the literature as it is rarely seen in childhood.

  6. Proprioceptive reflexes in patients with reflex sympathetic dystrophy. (United States)

    Schouten, A C; Van de Beek, W J T; Van Hilten, J J; Van der Helm, F C T


    Reflex sympathetic dystrophy (RSD) is a syndrome that frequently follows an injury and is characterized by sensory, autonomic and motor features of the affected extremities. One of the more common motor features of RSD is tonic dystonia, which is caused by impairment of inhibitory interneuronal spinal circuits. In this study the circuits that modulate the gain of proprioceptive reflexes of the shoulder musculature are quantitatively assessed in 19 RSD patients, 9 of whom presented with dystonia. The proprioceptive reflexes are quantified by applying two types of force disturbances: (1) disturbances with a fixed low frequency and a variable bandwidth and (2) disturbances with a small bandwidth around a prescribed centre frequency. Compared to controls, patients have lower reflex gains for velocity feedback in response to the disturbances around a prescribed centre frequency. Additionally, patients with dystonia lack the ability to generate negative reflex gains for position feedback, for these same disturbances. Proprioceptive reflexes to the disturbances with a fixed low frequency and variable bandwidth present no difference between patients and controls. Although dystonia in the RSD patients was limited to the distal musculature, the results suggest involvement of interneuronal circuits that mediate postsynaptic inhibition of the motoneurons of the proximal musculature.

  7. [Reflex sympathetic dystrophy]. (United States)

    Oliveira, Marta; Manuela, Manuela; Cantinho, Guilhermina


    Reflex Sympathetic Dystrophy is rare in pediatrics. It is a complex regional pain syndrome, of unknown etiology, usually post-traumatic, characterized by dysfunctions of the musculoskeletal, vascular and skin systems: severe persistent pain of a limb, sensory and vascular alterations, associated disability and psychosocial dysfunction. The diagnosis is based in high clinical suspection. In children and adolescents there are aspects that are different from the adult ones. Excessive tests may result in worsening of the clinical symptoms. Bone scintigraphy can help. Pain treatment is difficult, not specific. Physical therapies and relaxation technics give some relief. Depression must be treated. This syndrome includes fibromyalgia and complex regional pain syndrome type I. We present a clinical report of an adolescent girl, referred for pain, cold temperature, pallor and functional disability of an inferior limb, all signals disclosed by a minor trauma. She had been diagnosed depression the year before. The bone scintigraphy was a decisive test. The treatment with gabapentin, C vitamin, physiotherapy and pshycotherapy has been effective.

  8. Volitional control of reflex cough (United States)

    Bolser, Donald C.; Davenport, Paul W.


    Multiple studies suggest a role for the cerebral cortex in the generation of reflex cough in awake humans. Reflex cough is preceded by detection of an urge to cough; strokes specifically within the cerebral cortex can affect parameters of reflex cough, and reflex cough can be voluntarily suppressed. However, it is not known to what extent healthy, awake humans can volitionally modulate the cough reflex, aside from suppression. The aims of this study were to determine whether conscious humans can volitionally modify their reflexive cough and, if so, to determine what parameters of the cough waveform and corresponding muscle activity can be modified. Twenty adults (18–40 yr, 4 men) volunteered for study participation and gave verbal and written informed consent. Participants were seated and outfitted with a facemask and pneumotacograph, and two surface EMG electrodes were positioned over expiratory muscles. Capsaicin (200 μM) was delivered via dosimeter and one-way (inspiratory) valve attached to a side port between the facemask and pneumotachograph. Cough airflow and surface EMG activity were recorded across tasks including 1) baseline, 2) small cough (cough smaller or softer than normal), 3) long cough (cough longer or louder than normal), and 4) not cough (alternative behavior). All participants coughed in response to 200 μM capsaicin and were able to modify the cough. Variables exhibiting changes include those related to the peak airflow during the expiratory phase. Results demonstrate that it is possible to volitionally modify cough motor output characteristics. PMID:22492938

  9. Two ways to support reflexivity

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Knudsen, Hanne


    A current challenge to public managers is the lack of a well-defined role. How can master’s programmes prepare managers to live up to an undefined function? In this paper we argue that the lack of role description enhances the need for reflexivity and show how it is done at Master in Educational......’. This requires participants to conduct experiments in their own organization, to reflect on and analyse their experiences with concepts from the curriculum. While the new language and the experimental teaching format are difficult, the participants learn a reflexive practice that can enable them to life up...

  10. Outside home. Notes on reflexivity

    Directory of Open Access Journals (Sweden)

    Mara Clemente


    The paper proffers the idea in which a “reflexive process” on subjectivity can involve and/or hopefully involve the entire experience of the researcher, going beyond the borders of a single research. In the process, unexpected elements of subjectivity can come into play; in other cases the meaning attributed to them can change in time or can have a role different from what had been expected. Some elements, objects of epistemological analyses, as imposed by a reflexive approach, can become objects of attention also on the phenomenological level.

  11. Educating the Reflexive Practitioner

    Directory of Open Access Journals (Sweden)

    Marc J. Neveu


    wearing any clothes.Notwithstanding such issues, I do believe the studio holds the potentialto be an empowering learning experience. The intention of this article is to question the mode of instruction in an architectural studio. I’ve structured the paper in three parts. First, I will briefly describe the findingsof the study made by the Carnegie Foundation for the Advancementof Teaching known as the Boyer Report.2 To develop and support the findings of the Boyer Report, I introduce the work of the educator Donald Schön. Though I see much merit in the Boyer Report, and Schön’sproposals, I argue that a more nuanced approach is required. I will recommend, therefore, in the second section of this paper that a meansof architectural education as based on the Socratic method may be amore productive approach. My reading of the Socratic method is basedprimarily on early Socratic dialogues and I will specifically use Charmidesto illustrate the issues that I believe are relevant to studio pedagogy.3 From my analysis of Charmides I will, in the third section of the essay,describe how the Socratic method is beneficial to studio pedagogy threeways: reflexive, non-propositional, and finally how Socrates’ approachmay indeed be practical. This last section will be illustrated with a studentproject. It is my conjecture that the Socratic method offers insight intocurrent discussions of educational theory, namely student-centered,project-based learning.

  12. Soleus stretch reflex during cycling

    DEFF Research Database (Denmark)

    Grey, Michael James; Pierce, C. W.; Milner, T. E.


    The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions durin...

  13. Reflexive fatherhood in everyday life

    DEFF Research Database (Denmark)

    Westerling, Allan


    This article looks at fathering practices in Denmark, using the findings from a research project on everyday family life in Denmark. It takes a social psychological perspective and employs discursive psychology and theories about reflexive modernisation. It shows how fathers orient towards intima...

  14. The reflexive case study method

    DEFF Research Database (Denmark)

    Rittenhofer, Iris


    This paper extends the international business research on small to medium-sized enterprises (SME) at the nexus of globalization. Based on a conceptual synthesis across disciplines and theoretical perspectives, it offers management research a reflexive method for case study research of postnational...

  15. Ultrasound imaging of sacral reflexes

    NARCIS (Netherlands)

    de Jong, Tom P. V. M.; Klijn, Aart J.; Vijverberg, Marianne A. W.; de Kort, Laetitia M. O.


    To investigate the reliability of examination of the guarding reflex of the pelvic floor by dynamic perineal ultrasonography in children with bladder dysfunction and in controls. A total of 40 patients with nonneurogenic bladder/sphincter dyssynergia, 40 with spina bifida, and 40 controls underwent

  16. Integrating Reflexivity in Livelihoods Research

    DEFF Research Database (Denmark)

    Prowse, Martin


    Much poverty and development research is not explicit about its methodology or philosophical foundations. Based on the extended case method of Burawoy and the epistemological standpoint of critical realism, this paper discusses a methodological approach for reflexive inductive livelihoods researc...... that overcomes the unproductive social science dualism of positivism and social constructivism. The approach is linked to a conceptual framework and a menu of research methods that can be sequenced and iterated in light of research questions....

  17. Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity. (United States)

    Engward, Hilary; Davis, Geraldine


    A discussion of the meaning of reflexivity in research with the presentation of examples of how a model of reflexivity was used in a grounded theory research project. Reflexivity requires the researcher to make transparent the decisions they make in the research process and is therefore important in developing quality in nursing research. The importance of being reflexive is highlighted in the literature in relation to nursing research, however, practical guidance as to how to go about doing research reflexively is not always clearly articulated. This is a discussion paper. The concept of reflexivity in research is explored using the Alvesson and Skoldberg model of reflexivity and practical examples of how a researcher developed reflexivity in a grounded theory project are presented. Nurse researchers are encouraged to explore and apply the concept of reflexivity in their research practices to develop transparency in the research process and to increase robustness in their research. The Alvesson and Skoldberg model is of value in applying reflexivity in qualitative nursing research, particularly in grounded theory research. Being reflexive requires the researcher to be completely open about decisions that are made in the research process. The Alvesson and Skolberg model of reflexivity is a useful model that can enhance reflexivity in the research process. It can be a useful practical tool to develop reflexivity in grounded theory research. © 2015 John Wiley & Sons Ltd.

  18. Reflex syncope: Diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Richard Sutton


    Full Text Available For the diagnosis of reflex syncope, diligent history-building with the patient and a witness is required. In the Emergency Department (ED, the assessment of syncope is a challenge which may be addressed by an ED Observation Unit or by a referral to a Syncope Unit. Hospital admission is necessary for those with life-threatening cardiac conditions although risk stratification remains an unsolved problem. Other patients may be investigated with less urgency by carotid sinus massage (>40 years, tilt testing, and electrocardiogram loop recorder insertion resulting in a clear cause for syncope. Management includes, in general terms, patient education, avoidance of circumstances in which syncope is likely, increase in fluid and salt consumption, and physical counter-pressure maneuvers. In older patients, those that will benefit from cardiac pacing are now well defined. In all patients, the benefit of drug therapy is often disappointing and there remains no ideal drug. A role for catheter ablation may emerge for the highly symptomatic reflex syncope patient. Keywords: Cardiac pacing, Catheter ablation, Diagnosis, Drugs, Management, Reflex syncope

  19. Reflexive Aero Structures for Enhanced Survivability Project (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) will develop an advanced reflexive structure technology system to increase the survivability of future systems constructed of...

  20. Structural cure for reflex syncope? (United States)

    Sulke, Neil; Eysenck, William; Badiani, Sveeta; Furniss, Stephen


    The ROX Coupler is a device that allows creation of a central arteriovenous anastomosis at the iliac level. The device has been shown to improve exercise capacity in patients with chronic obstructive pulmonary disease and is CE marked for the treatment of resistant and uncontrolled hypertension. Reflex syncope is a challenging clinical condition with limited proven therapeutic options. We describe the resolution of symptoms and tilt table response of a patient who underwent insertion of a ROX Coupler to treat hypertension, and also incidentally had pre-existing vasodepressor syncope. 2016 BMJ Publishing Group Ltd.

  1. Dysautonomia, fibromyalgia and reflex dystrophy (United States)

    Eisinger, Jean


    Autonomic nervous system dysfunction observed in fibromyalgia, characterized without exception by a sympathetic hyperactivity and hyporeactivity, has been reported. However, several studies demonstrated reduced levels of norepinephrine and neuropeptide Y at rest and after tilt table in some patients, which was improved by beta-stimulating agents. These findings support heterogeneity in fibromyalgia-associated dysautonomia. Fibromyalgia could be a generalized sympathetic dystrophy since both conditions are activated by trauma and partly linked to sympathetic mechanisms. Yet they differ on several points: hormonal and neurochemical abnormalities are observed in fibromyalgia whereas activation by peripheral trauma and hyperosteolysis are observed in reflex sympathetic dystrophy. PMID:17626612

  2. [Reflex sympathetic dystrophy of childhood: one case]. (United States)

    Jouary, T; Boralevi, F; Pillet, P; Taieb, A; Léauté-Labrèze, C


    Reflex sympathetic dystrophy (Complex Regional Pain Syndrome type 1) is little known by dermatologists. We report a pediatric case of reflex sympathetic dystrophy with predominant cutaneous involvement. A 10 year-old girl presented a warm, painful and relapsing right hand edema for seven months (three outbreaks). The hand was cyanotic, pigmented and painful. Routine blood tests were normal. Radiography and radionuclide bone scan were consistent with stage 1 reflex sympathetic dystrophy. Physiotherapy led to dramatic improvement. Reflex sympathetic dystrophy is known since the XVIIIth century. In the last decade, progress in radiology and bone scan have provided elements for understanding the physiopathology of the disease. Microvascular abnormalities under the control of sympathetic nervous system are characteristic of different stages of reflex sympathetic dystrophy. Recently, neurovascular system experiments showed that sympathetic reflex tonus changes may be controlled by the central nervous system. Dermatologic changes of reflex sympathetic dystrophy are well known: edema and erythema in first stage, cyanosis in second stage, sclerosis and atrophia in third stage, but pediatric cases are rarely reported. Reflex sympathetic dystrophy is a complex disease, however its physiopathology is now understood. The clinical presentation can be atypical and the dermatologist may be the first to be consulted.

  3. Reflexive Aero Structures for Enhanced Survivability, Phase I (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) proposes to develop an advanced reflexive structure system to increase the survivability of aerostructures. This reflexive...

  4. Reflexive Learning through Visual Methods

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth


    What. This chapter concerns how visual methods and visual materials can support visually oriented, collaborative, and creative learning processes in education. The focus is on facilitation (guiding, teaching) with visual methods in learning processes that are designerly or involve design. Visual...... or professional, to facilitate with visual methods in a critical, reflective, and experimental way. The chapter offers recommendations for facilitating with visual methods to support playful, emergent designerly processes. The chapter also has a critical, situated perspective. Where. This chapter offers case...... challenges are discussed, including supporting difficult group collaborative processes (such as dealing with interpersonal tensions). You will gain an understanding about how and why to work with visual methods and how to develop a dynamic, reflexive facilitation practice. The chapter contains...

  5. Reflexive criteria of sociological research

    Directory of Open Access Journals (Sweden)

    R T Ubaydullaeva


    Full Text Available The article is devoted to the sociological criteria of explaining the way of thinking and actions of subjects, their spiritual and moral positions and intellectual forces that form the laws of social life. The author seeks to adapt such categories as ‘meaning of life’, ‘human dignity’, ‘rationality’ etc. for the purposes of sociological analysis by methodological construction of some real life dichotomies such as ‘subjective meaning and social function’, ‘the real and the ideal’, ‘the demanded and the excluded’. Thus, the author studies economic, political and technical processes in terms of both positivity and negativity of social interaction and states that given the increasing differentiation of the society and the contradictory trends of social development the reflexive criteria that take into account the socio-cultural nature of the man help to find one’s own model of development.

  6. A near catastrophe from trigeminocardiac reflex

    Directory of Open Access Journals (Sweden)

    Parmod K Bithal


    Full Text Available Trigeminocardiac reflex is a brainstem reflex that results from stimulation of any branch of the trigeminal nerve along its course. It produces a constellation of signs and symptoms decrease in blood pressure (BP and heart rate, dysrhythmias, apnoea and increased gastric motility. We present a case of 80-year-old female patient who developed alarming hypotension and bradycardia during craniotomy for meningioma excision resulting from this reflex. In the face of refractory hypotension despite administering ephedrine and phenylephrine, we had to resort to adrenaline to restore her normal BP.

  7. Situating reflexivities: voices, positionalities and representations in feminist ethnographic texts

    NARCIS (Netherlands)

    Nencel, L.S.


    This article traces the feminist discussion concerning the importance of reflexive analysis and reflexive writing for feminist research. It starts by describing two feminist currents that concern the way to be reflexive. The first, reflexivity as a corrective measure accords a great deal of

  8. Measurement of tendon reflexes by surface electromyography in normal subjects

    NARCIS (Netherlands)

    Stam, J.; van Crevel, H.


    A simple method for measuring the tendon reflexes was developed. A manually operated, electronic reflex hammer was applied that enabled measurement of the strength of tendon taps. Reflex responses were recorded by surface electromyography. Stimulus-response relations and latencies of tendon reflexes

  9. Portraying Reflexivity in Health Services Research. (United States)

    Rae, John; Green, Bill


    A model is proposed for supporting reflexivity in qualitative health research, informed by arguments from Bourdieu and Finlay. Bourdieu refers to mastering the subjective relation to the object at three levels-the overall social space, the field of specialists, and the scholastic universe. The model overlays Bourdieu's levels of objectivation with Finlay's three stages of research (pre-research, data collection, and data analysis). The intersections of these two ways of considering reflexivity, displayed as cells of a matrix, pose questions and offer prompts to productively challenge health researchers' reflexivity. Portraiture is used to show how these challenges and prompts can facilitate such reflexivity, as illustrated in a research project. © The Author(s) 2016.

  10. Reflexivity and the capacity to think. (United States)

    Doyle, Sarah


    Reflexivity is fundamental to qualitative health research, yet notoriously difficult to unpack. Drawing on Wilfred Bion's work on the development of the capacity to think and to learn, I show how the capacity to think is an impermanent and fallible capacity, with the potential to materialize or evaporate at any number of different points. I use this conceptualization together with examples from published interview data to illustrate the difficulties for researchers attempting to sustain a reflexive approach, and to direct attention toward the possibilities for recovering and supporting the capacity to think. I counter some of the criticisms suggesting that reflexivity can be self-indulgent, and suggest instead that self-indulgence constitutes a failure of reflexivity. In the concluding discussions I acknowledge tensions accompanying the use of psychoanalytic theories for research purposes, and point to emerging psychosocial approaches as one way of negotiating these.

  11. Entrepreneurship Teaching Conducted as Strategic Reflexive Conversation

    DEFF Research Database (Denmark)

    Kristiansson, Michael

    The paper intends exploring and ascertaining whether the concept of strategic reflexive conversation can profitably be applied to entrepreneurship. As a start, a process of conceptualisation is undertaken, which is instrumental in placing the notion of strategic reflexive conversation...... into a knowledge management perspective. Strategic reflexive conversation is presented in an enhanced and updated version, which is contrasted to entrepreneurship through reflection. The findings indicate and it can be concluded that, with some important reservations, strategic reflexive conversation can...... advantageously, and on a pilot basis, be applied to entrepreneurship in practical environments and within the framework of entrepreneurship-centred teaching. The present theoretical investigation is solely of an introductory nature and steps are considered that can lead to the planning of additional exploratory...

  12. [ Sudeck's bone atrophy (reflex sympathetic dystrophy)]. (United States)

    Hayashi, Yasufumi


    Reflex sympathetic dystrophy is a disease clinically characterized severe pain, allodynia (severe pain caused by a touch) and over-reaction of pain sensation after a minor injury. In 1994, reflex sympathetic dystrophy was given a name of complex regional pain syndrome type 1 by a international congress, because local blockade of the sympathetic nerve has not been found to be invariably effective. Treatment system for reflex sympathetic dystrophy is composed of medicament therapy including oral administration and/or injection of drug, physical therapy such as thermotherapy and gently passive movement, surgical treatment and psychotherapy. Treatment with injection of pamidronate for 23 patients with reflex sympathetic dystrophy revealed to reduced the grade of pain to two third compared to pre-treatment period, and local intravenous block with local anesthetic drug and steroid hormone disappeared the almost symptoms in cases of early phase.

  13. Morbidity in reflex sympathetic dystrophy (United States)

    Murray, C.; Cohen, A.; Perkins, T.; Davidson, J.; Sills, J.


    Reflex sympathetic dystrophy (RSD), an unusual diagnosis in general paediatrics, is well recognised by paediatric rheumatologists. This study reports the presentation and the clinical course of 46 patients (35 female, age range 8-15.2) with RSD. The patients saw professionals from an average of 2.3 specialties (range 1-5). Twenty five (54%) had a history of trauma. Median time to diagnosis was 12 weeks (range 1-130). Many children had multiple investigations and treatments. Once diagnosis was made, treatment followed with physiotherapy and analgesics. Median time to recovery was seven weeks (range 1-140), with 27.5% relapsing. Nine children required assessment by the child and adolescent psychiatry team. This disease, though rare, has significant morbidity and it is therefore important to raise clinicians' awareness of RSD in childhood. Children with the condition may then be recognised and referred for appropriate management earlier, and spared unnecessary investigations and treatments which may exacerbate the condition.


  14. Somatosensory and acoustic brain stem reflex myoclonus.


    Shibasaki, H; Kakigi, R; Oda, K; Masukawa, S


    A patient with brain stem reflex myoclonus due to a massive midbrain infarct was studied electrophysiologically. Myoclonic jerks were elicited at variable latencies by tapping anywhere on the body or by acoustic stimuli, and mainly involved flexor muscles of upper extremities. The existence of convergence of somatosensory and acoustic inputs in the brain stem was suggested. This myoclonus seemed to be mediated by a mechanism similar to the spino-bulbo-spinal reflex.

  15. The passive of reflexive verbs in Icelandic

    Directory of Open Access Journals (Sweden)

    Hlíf Árnadóttir


    Full Text Available The Reflexive Passive in Icelandic is reminiscent of the so-called New Passive (or New Impersonal in that the oblique case of a passivized object NP is preserved. As is shown by recent surveys, however, speakers who accept the Reflexive Passive do not necessarily accept the New Passive, whereas conversely, speakers who accept the New Passive do also accept the Reflexive Passive. Based on these results we suggest that there is a hierarchy in the acceptance of passive sentences in Icelandic, termed the Passive Acceptability Hierarchy. The validity of this hierarchy is confirmed by our diachronic corpus study of open access digital library texts from Icelandic journals and newspapers dating from the 19th and 20th centuries (tí Finally, we sketch an analysis of the Reflexive Passive, proposing that the different acceptability rates of the Reflexive and New Passives lie in the argument status of the object. Simplex reflexive pronouns are semantically dependent on the verbs which select them, and should therefore be analyzed as syntactic arguments only, and not as semantic arguments of these verbs.

  16. Reflexive convention: civil partnership, marriage and family. (United States)

    Heaphy, Brian


    Drawing on an analysis of qualitative interview data from a study of formalized same-sex relationships (civil partnerships) this paper examines the enduring significance of marriage and family as social institutions. In doing so, it intervenes in current debates in the sociology of family and personal life about how such institutions are undermined by reflexivity or bolstered by convention. Against the backdrop of dominating sociological frames for understanding the links between the changing nature of marriage and family and same-sex relationship recognition, the paper analyses the diverse and overlapping ways (including the simple, relational, strategic, ambivalent and critical ways) in which same-sex partners reflexively constructed and engaged with marriage and family conventions. My analysis suggests that instead of viewing reflexivity and convention as mutually undermining, as some sociologists of family and personal life do, it is insightful to explore how diverse forms of reflexivity and convention interact in everyday life to reconfigure the social institutions of marriage and family, but do not undermine them as such. I argue the case for recognizing the ways in which 'reflexive convention', or reflexive investment in convention, contributes to the continuing significance of marriage and family as social institutions. © London School of Economics and Political Science 2017.

  17. "On Becoming a Critically Reflexive Practitioner" Redux: What Does It Mean to "Be" Reflexive? (United States)

    Cunliffe, Ann L.


    In this commentary, Cunliffe states that is convinced that reflexivity offers a way of foregrounding our moral and ethical responsibility for people and for the world around us. To "BE" reflexive was defined as embracing "subjective understandings of reality as a basis for thinking more critically about the impact of our…

  18. Reflex and Non-Reflex Torque Responses to Stretch of the Human Knee Extensors

    National Research Council Canada - National Science Library

    Mrachacz-Kersting, N


    .... The quadriceps muscles were stretched at various background torques, produced either voluntarily or electrically and thus the purely reflex-mediated torque could be calculated. The contribution of the reflex mediated stiffness initially low, increased with increasing background torques for the range of torques investigated.

  19. Perfect Lighting for Facial Photography in Aesthetic Surgery: Ring Light. (United States)

    Dölen, Utku Can; Çınar, Selçuk


    Photography is indispensable for plastic surgery. On-camera flashes can result in bleached out detail and colour. This is why most of the plastic surgery clinics prefer studio lighting similar to professional photographers'. In this article, we want to share a simple alternative to studio lighting that does not need extra space: Ring light. We took five different photographs of the same person with five different camera and lighting settings: Smartphone and ring light; point and shoot camera and on-camera flash; point and shoot camera and studio lighting; digital single-lens reflex (DLSR) camera and studio lighting; DSLR and ring light. Then, those photographs were assessed objectively with an online survey of five questions answered by three distinct populations: plastic surgeons (n: 28), professional portrait photographers (n: 24) and patients (n: 22) who had facial aesthetic procedures. Compared to the on-camera flash, studio lighting better showed the wrinkles of the subject. The ring light facilitated the perception of the wrinkles by providing homogenous soft light in a circular shape rather than bursting flashes. The combination of a DSLR camera and ring light gave the oldest looking subject according to 64 % of responders. The DSLR camera and the studio lighting demonstrated the youngest looking subject according to 70 % of the responders. The majority of the responders (78 %) chose the combination of DSLR camera and ring light that exhibited the wrinkles the most. We suggest using a ring light to obtain well-lit photographs without loss of detail, with any type of cameras. However, smartphones must be avoided if standard pictures are desired. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors

  20. [Professional outcome of reflex sympathetic dystrophy]. (United States)

    Dauty, M; Renaud, P; Deniaud, C; Tortellier, L; Dubois, C


    In spite of physical medicine and rehabilitation care, post-traumatic reflex sympathetic dystrophy can be at the origin of articular deficiency, which decrease the capacity to return to work. The aim of this study is to know the professional future of patients who present post-traumatic reflex sympathetic dystrophy. Eighteen months prospective study, carried out from patients in age to work, hospitalized in physical medicine and rehabilitation unit for ostéo-articular traumatism complicated by reflex sympathetic dystrophy. Description of the population and comorbidity factors preventing professional resumption. Determination of the duration of medical certificate and the modalities of professional resumption. From 16 patients in age to work, only 12 were able to resume a full time profession with an average period of 10.5 months +/- 5. The importance of the, the distale articular location of reflex sympathetic dystrophy (wrist - hand, ankle - foot), the association with a comorbidity such as chronic alcoholism represent pejorative factors of working resumption. Organizations of workstation are often necessary in six cases over eight, if the job is not sedentary. In the most complicated cases, inaptitudes in the work are pronounced with demand of professional reclassifying. Post-traumatic reflex sympathetic dystrophy represents a real challenge for the rehabilitation team, to minimize deficiencies and to help the patient to become again a worker.

  1. Reflexive Planning as Design and Work

    DEFF Research Database (Denmark)

    Lissandrello, Enza; Grin, John


    In recent years, planning theorists have advanced various interpretations of the notion of reflexivity, inspired by American pragmatism, complexity theory, hermeneutics, discursive and collaborative planning. Scholars agree that “reflexivity” has a strong temporal dimension: it not only aims...... to solve present planning problems, but to imagine and understand alternative trajectories for future action. This article explores the practical utility of reflexivity for planners, through a case study that focuses on a project to promote sustainable development in the Port of Amsterdam. Reflexivity...... in planning emerges as a new tool for generating critical knowledge and dialogue that can synthesise the perspectives of multiple actors in a common understanding, existing structural constraints and a collective imagination of alternative future possibilities. Such research highlights the potential...

  2. Orthodoxy and reflexivity in international comparative analysis

    DEFF Research Database (Denmark)

    Lind, Jens; Valkenburg, Ben


    This contribution aims at four points.First we want to argue why we think a reflexive social science is more adequate than the orthodox consensus. In current practice much of the criticism on the orthodox consensus is shared on a theoretical level, without considering the implications and acting...... upon the consequences on the level of empirical research. We want to avoid that, so our second and third subject will be the practical implications of reflexivity for empirical research as well as for social policy. Our discussion on these subjects is based on the practical experiences in the INPART...... project, in which we have tried to deal with these consequences. Fourth, and hopefully as a result of the first three aims, we want to argue that a reflexive approach of international, comparative research is not only desirable, but attainable as well. In order to do so, we begin with a short discussion...

  3. Reflex sympathetic dystrophy: reflections from a clinician. (United States)

    Small, Eric


    Reflex sympathetic dystrophy is defined as chronic musculoskeletal pain and autonomic dysfunction. It is a difficult diagnosis to make, and the adolescent often sees many specialists before arriving at the correct diagnosis. In this article I review reflex sympathetic dystrophy and reflect on the differential diagnosis, pertinent medical history, personal characteristics of patients with reflex sympathetic dystrophy, physical examination, and laboratory evaluation. Principles of management are considered, including physical therapy, pharmacology, psychological therapy, and alternative therapies. Accurate diagnosis and management are critical for not prolonging the adolescent's and the family's suffering. It is important to provide aggressive physical therapy, stress management, relaxation training, and close follow-up. It is also critical to avoid immobilization, surgery, or invasive procedures and unnecessary tests.

  4. A Robust Automated Cataract Detection Algorithm Using Diagnostic Opinion Based Parameter Thresholding for Telemedicine Application

    Directory of Open Access Journals (Sweden)

    Shashwat Pathak


    Full Text Available This paper proposes and evaluates an algorithm to automatically detect the cataracts from color images in adult human subjects. Currently, methods available for cataract detection are based on the use of either fundus camera or Digital Single-Lens Reflex (DSLR camera; both are very expensive. The main motive behind this work is to develop an inexpensive, robust and convenient algorithm which in conjugation with suitable devices will be able to diagnose the presence of cataract from the true color images of an eye. An algorithm is proposed for cataract screening based on texture features: uniformity, intensity and standard deviation. These features are first computed and mapped with diagnostic opinion by the eye expert to define the basic threshold of screening system and later tested on real subjects in an eye clinic. Finally, a tele-ophthamology model using our proposed system has been suggested, which confirms the telemedicine application of the proposed system.

  5. Radiometric calibration of wide-field camera system with an application in astronomy (United States)

    Vítek, Stanislav; Nasyrova, Maria; Stehlíková, Veronika


    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

  6. Munchausen's syndrome simulating reflex sympathetic dystrophy. (United States)

    Rodriguez-Moreno, J; Ruiz-Martin, J M; Mateo-Soria, L; Rozadilla, A; Roig-Escofet, D


    A 15 year old girl who had pain, oedema of her left hand, and fever of four months' duration is described. Marked demineralisation of her hand was shown by radiography, and increased articular uptake by technetium-99m bone scan. All these changes were indistinguishable from reflex sympathetic dystrophy. After two admissions to hospital and multiple explorations we discovered that she had induced her symptoms herself and a diagnosis of Munchausen's syndrome was made. As far as we know this presentation has not been previously reported and might help to explain the physiopathology of some signs of reflex sympathetic dystrophy. Images PMID:2270960

  7. Probabilities on Streams and Reflexive Games

    Directory of Open Access Journals (Sweden)

    Andrew Schumann


    Full Text Available Probability measures on streams (e.g. on hypernumbers and p-adic numbers have been defined. It was shown that these probabilities can be used for simulations of reflexive games. In particular, it can be proved that Aumann's agreement theorem does not hold for these probabilities. Instead of this theorem, there is a statement that is called the reflexion disagreement theorem. Based on this theorem, probabilistic and knowledge conditions can be defined for reflexive games at various reflexion levels up to the infinite level. (original abstract

  8. The stretch reflex and the contributions of C David Marsden. (United States)

    Bhattacharyya, Kalyan B


    The stretch reflex or myotatic reflex refers to the contraction of a muscle in response to its passive stretching by increasing its contractility as long as the stretch is within physiological limits. For ages, it was thought that the stretch reflex was of short latency and it was synonymous with the tendon reflex, subserving the same spinal reflex arc. However, disparities in the status of the two reflexes in certain clinical situations led Marsden and his collaborators to carry out a series of experiments that helped to establish that the two reflexes had different pathways. That the two reflexes are dissociated has been proved by the fact that the stretch reflex and the tendon reflex, elicited by stimulation of the same muscle, have different latencies, that of the stretch reflex being considerably longer. They hypothesized that the stretch reflex had a transcortical course before it reached the spinal motor neurons for final firing. Additionally, the phenomenon of stimulus-sensitive cortical myoclonus lent further evidence to the presence of the transcortical loop where the EEG correlate preceded the EMG discharge. This concept has been worked out by later neurologists in great detail, and the general consensus is that indeed, the stretch reflex is endowed with a conspicuous transcortical component.

  9. The stretch reflex and the contributions of C David Marsden

    Directory of Open Access Journals (Sweden)

    Kalyan B Bhattacharyya


    Full Text Available The stretch reflex or myotatic reflex refers to the contraction of a muscle in response to its passive stretching by increasing its contractility as long as the stretch is within physiological limits. For ages, it was thought that the stretch reflex was of short latency and it was synonymous with the tendon reflex, subserving the same spinal reflex arc. However, disparities in the status of the two reflexes in certain clinical situations led Marsden and his collaborators to carry out a series of experiments that helped to establish that the two reflexes had different pathways. That the two reflexes are dissociated has been proved by the fact that the stretch reflex and the tendon reflex, elicited by stimulation of the same muscle, have different latencies, that of the stretch reflex being considerably longer. They hypothesized that the stretch reflex had a transcortical course before it reached the spinal motor neurons for final firing. Additionally, the phenomenon of stimulus-sensitive cortical myoclonus lent further evidence to the presence of the transcortical loop where the EEG correlate preceded the EMG discharge. This concept has been worked out by later neurologists in great detail , and the general consensus is that indeed, the stretch reflex is endowed with a conspicuous transcortical component.

  10. Charitable giving and reflexive individuals: How personal reflexivity mediates between structure and agency. (United States)

    Sanghera, Balihar


    This article examines how individuals are reflexive beings who interpret the world in relation to things that matter to them, and how charitable acts are evaluated and embedded in their lives with different degrees of meaning and importance. Rather than framing the discussion of charitable practices in terms of an altruism/egoism binary or imputing motivations and values to social structures, the article explains how reflexivity is an important and neglected dimension of social practices, and how it interacts with sympathy, sentiments and discourses to shape giving. The study also shows that there are different modes of reflexivity, which have varied effects on charity and volunteering.

  11. A simple measurement hammer for quantitative reflex studies

    NARCIS (Netherlands)

    Stam, J.; van Leeuwen, J. R.


    A reflex hammer for measurement of the mechanical stimulus strength was designed. Combined with standard EMG equipment this instrument permits the study of both stimulus-response relations and latencies of myotatic reflexes. Some results in normal subjects are discussed

  12. Comparison of Stretch Reflex Torques in Ankle Dorsiflexors and Plantarflexors

    National Research Council Canada - National Science Library

    Tung, J


    ...) ankle muscles, Pulse, step, and a combination of random perturbation and step inputs were used to identify the reflex and intrinsic contributions to the measured torque, TA reflex torques were very...

  13. Biological Motion Cues Trigger Reflexive Attentional Orienting (United States)

    Shi, Jinfu; Weng, Xuchu; He, Sheng; Jiang, Yi


    The human visual system is extremely sensitive to biological signals around us. In the current study, we demonstrate that biological motion walking direction can induce robust reflexive attentional orienting. Following a brief presentation of a central point-light walker walking towards either the left or right direction, observers' performance…

  14. On Becoming a Critically Reflexive Practitioner (United States)

    Cunliffe, Ann L.


    Critically reflexive practice embraces subjective understandings of reality as a basis for thinking more critically about the impact of our assumptions, values, and actions on others. Such practice is important to management education, because it helps us understand how we constitute our realities and identities in relational ways and how we can…

  15. Bases for Cones and Reflexivity | Polyrakis | Quaestiones ...

    African Journals Online (AJOL)

    It is proved that a Banach space E is non-reflexive if and only if E has a closed cone with an unbounded, closed, dentable base. If E is a Banach lattice, the same characterization holds with the extra assumption that the cone is contained in E+. This article is also a survey of the geometry (dentability) of bases for cones.

  16. Reflexivity on Banach Spaces of Analytic Functions

    Directory of Open Access Journals (Sweden)

    B. Yousefi and J. Doroodgar


    Full Text Available . Let X be a Banach space of functions analytic on a plane domain Ω such that for every λ in Ω the functional of evaluation at λ is bounded. Assume further that X contains the constants and admits multiplication by the independent variable z, Mz, as a bounded operator. We give sufficient conditions for Mz to be reflexive.

  17. Reflex epilepsy: triggers and management strategies

    Directory of Open Access Journals (Sweden)

    Okudan ZV


    Full Text Available Zeynep Vildan Okudan,1 Çiğdem Özkara2 1Department of Neurology, Bakirkoy Dr Sadi Konuk Education and Research Hospital, 2Department of Neurology and Clinical Neurophysiology, Cerrahpasa Faculty of Medicine, University of Istanbul, Istanbul, Turkey Abstract: Reflex epilepsies (REs are identified as epileptic seizures that are consistently induced by identifiable and objective-specific triggers, which may be an afferent stimulus or by the patient’s own activity. RE may have different subtypes depending on the stimulus characteristic. There are significant clinical and electrophysiologic differences between different RE types. Visual stimuli-sensitive or photosensitive epilepsies constitute a large proportion of the RE and are mainly related to genetic causes. Reflex epilepsies may present with focal or generalized seizures due to specific triggers, and sometimes seizures may occur spontaneously. The stimuli can be external (light flashes, hot water, internal (emotion, thinking, or both and should be distinguished from triggering precipitants, which most epileptic patients could report such as emotional stress, sleep deprivation, alcohol, and menstrual cycle. Different genetic and acquired factors may play a role in etiology of RE. This review will provide a current overview of the triggering factors and management of reflex seizures. Keywords: seizure, reflex epilepsy, photosensitivity, hot water, reading, thinking

  18. Reflectivity, Reflexivity and Situated Reflective Practice (United States)

    Malthouse, Richard; Roffey-Barentsen, Jodi; Watts, Mike


    This paper describes an aspect of reflective practice referred to as situated reflective practice. The overarching theory is derived from social theories of structuration and reflexivity. In particular, from Giddens' theory of structuration, which sees social life as an interplay of agency and structure. Discussion of the research reported here…

  19. Blink reflex in type 2 diabetes mellitus. (United States)

    Elkholy, Saly H; Hosny, Hanan M; Shalaby, Nevein M; El-Hadidy, Reem A; Abd El-Rahim, Noha T; Mohamed, Manal M


    An evaluation of the extent of damage of the central nervous system in diabetes mellitus is of high value in current research. Electrophysiological abnormalities are frequently present in asymptomatic patients with diabetes mellitus. Diabetic cranial neuropathy is one of the complications of the disease. Blink reflex is used to diagnose subclinical cranial neuropathy. The objective is to test the utility of blink reflex in detecting subclinical cranial nerve involvement in patients with type 2 diabetes mellitus. Forty patients with type 2 diabetes mellitus, aged from 30 to 60 years examined clinically and neurologically. Blink reflex and nerve conduction studies for the upper and lower limbs were performed and compared with 20 matched normal controls. Diabetic patients with peripheral neuropathy showed significant prolonged distal latency and reduced amplitudes of the R2C response compared with the control, patients without peripheral neuropathy showed insignificant changes. Alteration of R2 correlated with the type of treatment and the duration of the disease. In patients without peripheral neuropathy, ulnar sensory distal latencies showed significant positive correlation with R2I latency, whereas its Conduction Velocity (CV) showed significant positive correlation with R2C amplitudes and negative correlation with R2C latency. R2C is the most sensitive parameter in the blink reflex, which can help in the diagnosis of subclinical diabetic cranial neuropathy.

  20. The acoustic reflex threshold in aging ears. (United States)

    Silverman, C A; Silman, S; Miller, M H


    This study investigates the controversy regarding the influence of age on the acoustic reflex threshold for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators between Jerger et al. [Mono. Contemp. Audiol. 1 (1978)] and Jerger [J. Acoust. Soc. Am. 66 (1979)] on the one hand and Silman [J. Acoust. Soc. Am. 66 (1979)] and others on the other. The acoustic reflex thresholds for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators were evaluated under two measurement conditions. Seventy-two normal-hearing ears were drawn from 72 subjects ranging in age from 20-69 years. The results revealed that age was correlated with the acoustic reflex threshold for BBN activator but not for any of the tonal activators; the correlation was stronger under the 1-dB than under the 5-dB measurement condition. Also, the mean acoustic reflex thresholds for broadband noise activator were essentially similar to those reported by Jerger et al. (1978) but differed from those obtained in this study under the 1-dB measurement condition.

  1. New Molecular Knowledge Towards the Trigemino-Cardiac Reflex as a Cerebral Oxygen-Conserving Reflex

    Directory of Open Access Journals (Sweden)

    N. Sandu


    Full Text Available The trigemino-cardiac reflex (TCR represents the most powerful of the autonomous reflexes and is a subphenomenon in the group of the so-called “oxygen-conserving reflexes”. Within seconds after the initiation of such a reflex, there is a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF, with no changes in the cerebral metabolic rate of oxygen (CMRO2 or in the cerebral metabolic rate of glucose (CMRglc. Such an increase in regional CBF without a change of CMRO2 or CMRglc provides the brain with oxygen rapidly and efficiently. Features of the reflex have been discovered during skull base surgery, mediating reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus, which finally engage a small population of neurons in the cortex. This cortical center appears to be dedicated to transduce a neuronal signal reflexively into cerebral vasodilatation and synchronization of electrocortical activity; a fact that seems to be unique among autonomous reflexes. Sympathetic excitation is mediated by cortical-spinal projection to spinal preganglionic sympathetic neurons, whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to the brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Previous studies showed a great variability in the human TCR response, in special to external stimuli and individual factors. The TCR gives, therefore, not only new insights into novel therapeutic options for a range of disorders characterized by neuronal death, but also into the cortical and molecular organization of the brain.

  2. Short reflex expirations (expiration reflexes) induced by mechanical stimulation of the trachea in anesthetized cats


    Poliacek, Ivan; Rose, Melanie J; Corrie, Lu Wen-Chi; Wang, Cheng; Jakus, Jan; Barani, Helena; Stransky, Albert; Polacek, Hubert; Halasova, Erika; Bolser, Donald C


    Fifty spontaneously breathing pentobarbital-anesthetized cats were used to determine the incidence rate and parameters of short reflex expirations induced by mechanical stimulation of the tracheal mucosa (ERt). The mechanical stimuli evoked coughs; in addition, 67.6% of the stimulation trials began with ERt. The expiration reflex mechanically induced from the glottis (ERg) was also analyzed (99.5% incidence, p < 0.001 compared to the incidence of ERt). We found that the amplitudes of abdomina...

  3. Effects of isoflurane on the baroreceptor reflex. (United States)

    Seagard, J L; Elegbe, E O; Hopp, F A; Bosnjak, Z J; von Colditz, J H; Kalbfleisch, J H; Kampine, J P


    The baroreceptor reflex has been found to be attenuated during anesthesia, but the effects of the relatively new anesthetic, isoflurane, on baroreflex function have not been examined thoroughly. This study was performed to determine the effects of isoflurane on each component of the baroreceptor reflex arc, including the receptors, afferent and efferent nerve pathways, central integratory centers, peripheral ganglia, and the heart. Baroreflex effects on heart rate initiated by systemic pressure changes were examined in conscious and anesthetized dogs (1.3% and 2.6% isoflurane). The effects on individual components of the reflex arc were determined by examining carotid sinus baroreceptor afferent activity, sympathetic efferent nerve activity, and heart rate response to direct sympathetic and parasympathetic efferent nerve stimulation in anesthetized dogs. Preganglionic and postganglionic nerve activities were recorded simultaneously during baroreflex activation to determine ganglionic effects of isoflurane. Baroreflex-induced changes in heart rate were not depressed significantly until 2.6% isoflurane if blood pressure changes due to anesthetic administration were prevented. Significant decreases in baseline sympathetic efferent nerve activity were found at 1.3% and 2.6% isoflurane, with depression of postganglionic activity significantly greater than preganglionic activity at 2.6% isoflurane, indicating a ganglionic effect of isoflurane. Cardiac chronotropic responses to direct stimulation of sympathetic and vagal fibers were attenuated significantly by isoflurane, with sympathetic stimulation showing the greater sensitivity to the anesthetic. Carotid baroreceptor afferent activity was increased by isoflurane, and this sensitization of the baroreceptors appeared to contribute to the decreased levels of sympathetic tone. Therefore, although isoflurane was found to alter the baroreceptor reflex through its effects at multiple sites of the baroreflex arc, significant

  4. Catching Cosmic Rays with a DSLR (United States)

    Sibbernsen, Kendra


    Cosmic rays are high-energy particles from outer space that continually strike the Earth's atmosphere and produce cascades of secondary particles, which reach the surface of the Earth, mainly in the form of muons. These particles can be detected with scintillator detectors, Geiger counters, cloud chambers, and also can be recorded with commonly…

  5. Reflexive cartography a new perspective in mapping

    CERN Document Server

    Casti, Emanuela


    Reflexive Cartography addresses the adaptation of cartography, including its digital forms (GIS, WebGIS, PPGIS), to the changing needs of society, and outlines the experimental context aimed at mapping a topological space. Using rigorous scientific analysis based on statement consistency, relevance of the proposals, and model accessibility, it charts the transition from topographical maps created by state agencies to open mapping produced by citizens. Adopting semiotic theory to uncover the complex communicative mechanisms of maps and to investigate their ability to produce their own messages and new perspectives, Reflexive Cartography outlines a shift in our way of conceptualizing maps: from a plastic metaphor of reality, as they are generally considered, to solid tools that play the role of agents, assisting citizens as they think and plan their own living place and make sense of the current world. Applies a range of technologies to theoretical perspectives on mapping to innovatively map the world's geogr...

  6. The Reflexive Principle of Sociological Theorization

    Directory of Open Access Journals (Sweden)

    R T Ubaidullayeva


    Full Text Available The article attempts to describe the reflexive principle in theory-making, which integrates the basic modern methodological paradigms and lays the foundation for the development of sociology. On the basis of the theoretical ideas of P. Bourdieu, A. Giddens and P. Ricoeur the author defines the concept of social reflexion and reveals its peculiarities in sociology as compared to reflexion in philosophy. According to the author, the fulfillment of reflexive functions in sociology is connected with the task of analyzing the complex structure of the polysemantic object, considering the specific quality of the subjects and their various trends of development. The presence of the poles — objectivity-subjectivity, rationality-irrationality, consciousness-unconsciousness etc, requires a reproduction of the dichotomies engendering them in social life and development of cognitive methods for their study in sociology.

  7. Reflex sympathetic dystrophy syndrome in a child. (United States)

    Badri, Talel; Ben Jennet, Salima; Fenniche, Samy; Benmously, Rym; Mokhtar, Inçaf; Hammami, Hatem


    Reflex sympathetic dystrophy syndrome (RSDS) is a painful condition that usually follows regional trauma. We report the case of a 13-year-old girl that was seen for a painful swelling of the right hand associated with palmar hyperhidrosis, which occurred after a trauma to the hand. Bone scan images showed early tissue abnormality, which was more significant on the right hand and wrist, as well as moderate bone uptake on the right side. Nonsteroidal anti-inflammatory drugs and alternating hot and cold baths led to a marked improvement. RSDS occurs following trauma or subsequent to various diseases or drug intake. This syndrome is related to impaired tissue microvasculature under the influence of abnormal sympathetic reflex hyperactivity. Bone scan is the diagnostic procedure of choice in RSDS, but it may be normal. Physiotherapy should be preferred in pediatric cases.

  8. Human investigations into the exercise pressor reflex

    DEFF Research Database (Denmark)

    Secher, Niels H; Amann, Markus


    . The importance of the exercise pressor reflex for tight cardiovascular regulation during dynamic exercise is supported by studies using pharmacological blockade of lower limb muscle afferent nerves. These experiments show attenuation of the increase in BP and cardiac output when exercise is performed......During exercise, neural input from skeletal muscles reflexly maintains or elevates blood pressure (BP) despite a maybe fivefold increase in vascular conductance. This exercise pressor reflex is illustrated by similar heart rate (HR) and BP responses to electrically induced and voluntary exercise...... with attenuated neural feedback. Additionally, there is no BP response to electrically induced exercise with paralysing epidural anaesthesia or when similar exercise is evoked in paraplegic patients. Furthermore, BP decreases when electrically induced exercise is carried out in tetraplegic patients. The lack...

  9. Ontogenetic development of vestibular reflexes in amphibians

    Directory of Open Access Journals (Sweden)

    Hans Straka


    Full Text Available Vestibulo-ocular reflexes ensure gaze stability during locomotion and passively induced head/body movements. In precocial vertebrates such as amphibians, vestibular reflexes are required very early at the onset of locomotor activity. While the formation of inner ears and the assembly of sensory-motor pathways is largely completed soon after hatching, angular and translational/tilt vestibulo-ocular reflexes (VOR display differential functional onsets and mature with different time courses. Otolith-derived eye movements appear immediately after hatching, whereas the appearance and progressive amelioration of semicircular canal-evoked eye movements is delayed and dependent on the acquisition of sufficiently large semicircular canal diameters. Moreover, semicircular canal functionality is also required to tune the initially omnidirectional otolith-derived VOR. The tuning is due to a reinforcement of those vestibulo-ocular connections that are co-activated by semicircular canal and otolith inputs during natural head/body motion. This suggests that molecular mechanisms initially guide the basic ontogenetic wiring, whereas semicircular canal-dependent activity is required to establish the spatio-temporal specificity of the reflex. While a robust VOR is activated during passive head/body movements, locomotor efference copies provide the major source for compensatory eye movements during tail- and limb-based swimming of larval and adult frogs. The integration of active/passive motion-related signals for gaze stabilization occurs in central vestibular neurons that are arranged as segmentally iterated functional groups along rhombomere 1-8. However, at variance with the topographic maps of most other sensory systems, the sensory-motor transformation of motion-related signals occurs in segmentally specific neuronal groups defined by the extraocular motor output targets.

  10. Entrepreneurship Teaching Conducted as Strategic Reflexive Conversation

    DEFF Research Database (Denmark)

    Kristiansson, Michael

    and be applied to entrepreneurship-centred instructional activities. The concept of strategic reflexive conversation must be regarded as relevant and are of clear pertinence to theoretical and practical entrepreneurship to entrepreneurship-oriented teaching and learning activities....... advantageously, and on a pilot basis, be applied to entrepreneurship in practical environments and within the framework of entrepreneurship-centred teaching. The present theoretical investigation is solely of an introductory nature and steps are considered that can lead to the planning of additional exploratory...

  11. Otolith and canal reflexes in human standing (United States)

    Cathers, Ian; Day, Brian L; Fitzpatrick, Richard C


    We used galvanic vestibular stimulation (GVS) to identify human balance reflexes of the semicircular canals and otolith organs. The experiment used a model of vestibular signals arising from GVS modulation of the net signal from vestibular afferents. With the head upright, the model predicts that the GVS-evoked canal signal indicates lateral head rotation while the otolith signal indicates lateral tilt or acceleration. Both signify body sway transverse to the head. With the head bent forward, the model predicts that the canal signal indicates body spin about a vertical axis but the otolith signal still signifies lateral body motion. Thus, we compared electromyograms (EMG) in the leg muscles and body sway evoked by GVS when subjects stood with the head upright or bent forward. With the head upright, GVS evoked a large sway in the direction of the anodal electrode. This response was abolished with the head bent forward leaving only small, oppositely directed, transient responses at the start and end of the stimulus. With the head upright, GVS evoked short-latency (60–70 ms), followed by medium-latency (120 ms) EMG responses, of opposite polarity. Bending the head forward abolished the medium-latency but preserved the short-latency response. This is compatible with GVS evoking separate otolithic and canal reflexes, indicating that balance is controlled by independent canal and otolith reflexes, probably through different pathways. We propose that the short-latency reflex and small transient sway are driven by the otolith organs and the medium-latency response and the large sway are driven by the semicircular canals. PMID:15618274

  12. Evolutionary problems in non-reflexive spaces

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.


    Roč. 16, č. 1 (2010), s. 1-22 ISSN 1262-3377 R&D Projects: GA AV ČR IAA1075402 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * energetic solution * energies with linear growth * oscillations * relaxation Subject RIV: BA - General Mathematics Impact factor: 1.084, year: 2009 problems in non-reflexive spaces.pdf

  13. Basic Gravitational Reflexes in the Larval Frog (United States)

    Cochran, Stephen L.


    This investigation was designed to determine how a primitive vertebrate, the bullfrog tadpole, is able to sense and process gravitational stimuli. Because of the phylogenetic similarities of the vestibular systems in all vertebrates, the understanding of the gravitational reflexes in this relatively simple vertebrate should elucidate a skeletal framework on a elementary level, upon which the more elaborate reflexes of higher vertebrates may be constructed. The purpose of this study was to understand how the nervous system of the larval amphibian processes gravitational information. This study involved predominantly electrophysiological investigations of the isolated, alert (forebrain removed) bullfrog tadpole head. The focus of these experiments is threefold: (1) to understand from whole extraocular nerve recordings the signals sent to the eye following static gravitational tilt of the head; (2) to localize neuronal centers responsible for generating these signals through reversible pharmacological ablation of these centers; and (3) to record intracellularly from neurons within these centers in order to determine the single neuron's role in the overall processing of the center. This study has provided information on the mechanisms by which a primitive vertebrate processes gravitational reflexes.

  14. Polyfunctionality and distribution of reflexive verbs in Latvian

    Directory of Open Access Journals (Sweden)

    Andra Kalnača


    Full Text Available The aim of the current paper is to analyze Latvian reflexive verbs from the point of view of their polyfunctionality and distributon.The polysemy of the reflexive verbs is not usually disucussed in the connection with its distribution pattern in the sentence either. This can be partly explianed by the fact that the reflexive verb can have some non-standard language meanings, which following the established practice of the traditional grammars and sometimes even dictionaries,  were not depicted in the language system description either. So the current paper is an attempt to analyze the polyfunctionality of reflexive verbs in connection with their semantic and syntactic functions, without judging the language use from the normative point of view.The classification of Latvian reflexive verbs is based on the relationship between semantic roles and syntactic structure according to the principles devised by Palmer (1994 and Saeed (1997.One and the same reflexive verb may have different lexical meanings with a different distribution for each of the meanings. One and the same verb can belong to different subclasses of the subject and object (or impersonal verbs.Some reflexive verbs have evaluative or aspectual (iterative meanings. The evaluative meanings usually are manifested by a positive or negative assessment of the event (the context can be enhanced by the adverbs good or bad and the consequences while the aspectual meaning is manifested by the intensity of the action, that is – iterativity.The study confirms the assumption that reflexive verbs are independent lexemes as opposed to non-reflexive verb forms. Each reflexive verb has its distinct semantic system and distribution which is different from polysemy of non-reflexive verbs and their distribution. The system of reflexive verbs in Latvian is open where new meanings and even new reflexive verbs arise particularly in colloquial use.

  15. The swallowing reflex and its significance as an airway defensive reflex

    Directory of Open Access Journals (Sweden)

    Takashi eNishino


    Full Text Available Swallowing function, in humans, is very complex. Swallowing plays, not only an important role in food digestion, but also a major role in preventing the entrance of food and/or other materials into the lower respiratory tract. To achieve this, precise coordination is necessary between breathing and swallowing since the pharynx serves as a common pathway for both respiration and digestion. The swallowing reflex consists of afferent pathways, central integration, and efferent pathways. Any defect or disorder along reflex arc can cause a potential delay or impairment in swallow function. The swallowing reflex can be modulated not only by pathological factors but also by physiological factors. Among these, timing of swallows in relation to the phase of respiration may be the most important factor that determines the occurrence of pulmonary aspiration, since phases of inspiration and the expiration-inspiration transition are the most vulnerable for pulmonary aspiration.

  16. Photography in Dermatologic Surgery: Selection of an Appropriate Camera Type for a Particular Clinical Application. (United States)

    Chen, Brian R; Poon, Emily; Alam, Murad


    Photographs are an essential tool for the documentation and sharing of findings in dermatologic surgery, and various camera types are available. To evaluate the currently available camera types in view of the special functional needs of procedural dermatologists. Mobile phone, point and shoot, digital single-lens reflex (DSLR), digital medium format, and 3-dimensional cameras were compared in terms of their usefulness for dermatologic surgeons. For each camera type, the image quality, as well as the other practical benefits and limitations, were evaluated with reference to a set of ideal camera characteristics. Based on these assessments, recommendations were made regarding the specific clinical circumstances in which each camera type would likely be most useful. Mobile photography may be adequate when ease of use, availability, and accessibility are prioritized. Point and shoot cameras and DSLR cameras provide sufficient resolution for a range of clinical circumstances, while providing the added benefit of portability. Digital medium format cameras offer the highest image quality, with accurate color rendition and greater color depth. Three-dimensional imaging may be optimal for the definition of skin contour. The selection of an optimal camera depends on the context in which it will be used.

  17. Using the iPhone as a device for a rapid quantitative analysis of trinitrotoluene in soil. (United States)

    Choodum, Aree; Kanatharana, Proespichaya; Wongniramaikul, Worawit; Daeid, Niamh Nic


    Mobile 'smart' phones have become almost ubiquitous in society and are typically equipped with a high-resolution digital camera which can be used to produce an image very conveniently. In this study, the built-in digital camera of a smart phone (iPhone) was used to capture the results from a rapid quantitative colorimetric test for trinitrotoluene (TNT) in soil. The results were compared to those from a digital single-lens reflex (DSLR) camera. The colored product from the selective test for TNT was quantified using an innovative application of photography where the relationships between the Red Green Blue (RGB) values and the concentrations of colorimetric product were exploited. The iPhone showed itself to be capable of being used more conveniently than the DSLR while providing similar analytical results with increased sensitivity. The wide linear range and low detection limits achieved were comparable with those from spectrophotometric quantification methods. Low relative errors in the range of 0.4 to 6.3% were achieved in the analysis of control samples and 0.4-6.2% for spiked soil extracts with good precision (2.09-7.43% RSD) for the analysis over 4 days. The results demonstrate that the iPhone provides the potential to be used as an ideal novel platform for the development of a rapid on site semi quantitative field test for the analysis of explosives. © 2013 Elsevier B.V. All rights reserved.

  18. The PANOPTES project: discovering exoplanets with low-cost digital cameras (United States)

    Guyon, Olivier; Walawender, Josh; Jovanovic, Nemanja; Butterfield, Mike; Gee, Wilfred T.; Mery, Rawad


    The Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanets Survey (PANOPTES, project is aimed at identifying transiting exoplanets using a wide network of low-cost imaging units. Each unit consists of two commercial digital single lens reflex (DSLR) cameras equipped with 85mm F1.4 lenses, mounted on a small equatorial mount. At a few $1000s per unit, the system offers a uniquely advantageous survey eficiency for the cost, and can easily be assembled by amateur astronomers or students. Three generations of prototype units have so far been tested, and the baseline unit design, which optimizes robustness, simplicity and cost, is now ready to be duplicated. We describe the hardware and software for the PANOPTES project, focusing on key challenging aspects of the project. We show that obtaining high precision photometric measurements with commercial DSLR color cameras is possible, using a PSF-matching algorithm we developed for this project. On-sky tests show that percent-level photometric precision is achieved in 1 min with a single camera. We also discuss hardware choices aimed at optimizing system robustness while maintaining adequate cost. PANOPTES is both an outreach project and a scientifically compelling survey for transiting exoplanets. In its current phase, experienced PANOPTES members are deploying a limited number of units, acquiring the experience necessary to run the network. A much wider community will then be able to participate to the project, with schools and citizen scientists integrating their units in the network.

  19. The legacy of care as reflexive learning. (United States)

    García, Marta Rodríguez; Moya, Jose Luis Medina


    to analyze whether the tutor's use of reflexive strategies encourages the students to reflect. The goal is to discover what type of strategies can help to achieve this and how tutors and students behave in the practical context. a qualitative and ethnographic focus was adopted. Twenty-seven students and 15 tutors from three health centers participated. The latter had received specific training on reflexive clinical tutoring. The analysis was developed through constant comparisons of the categories. the results demonstrate that the tutors' use of reflexive strategies such as didactic questioning, didactic empathy and pedagogical silence contributes to encourage the students' reflection and significant learning. reflexive practice is key to tutors' training and students' learning. analisar se o uso de estratégias reflexivas por parte da tutora de estágio clínico estimula a reflexão nos estudantes. A intenção é descobrir qual tipo de estratégias podem ajudar a fazê-lo e como as tutoras e os estudantes se comportam no contexto prático. foi adotado um enfoque qualitativo de cunho etnográfico em que participaram 27 estudantes e 15 tutores de três centros de saúde que haviam recebido formação específica sobre tutoria clínica reflexiva. A análise foi realizada por meio de comparações constantes das categorias. os resultados demonstram que o uso de estratégias reflexivas como a interrogação didática, a empatia didática e o silêncio pedagógico por parte das tutoras, contribui para fomentar a reflexão do estudante e sua aprendizagem significativa. a prática reflexiva é a chave para a formação dos tutores e para a aprendizagem dos estudantes. analizar si el uso de estrategias reflexivas por parte de la tutora de prácticas clínicas fomenta la reflexión en los estudiantes. Se trata de conocer qué tipo de estrategias pueden ayudar a hacerlo y cómo se comportan tutoras y estudiantes en el contexto práctico. se ha utilizado un enfoque

  20. Reflexive Aero Structures for Enhanced Survivability, Phase II (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) will develop an advanced reflexive structure technology system to increase the survivability of future systems constructed of...

  1. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O


    sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno......Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human...

  2. Reflex sympathetic dystrophy following pacemaker insertion. (United States)

    Londhey, Vikram A; Singh, Nishant; Kini, Seema


    A 55 year old male presented with pain and swelling over dorsum of right hand and small joints, and loss of sweating over right hand since two months. He was a known case of mitral valve prolapse (MVP) with mitral regurgitation and complete heart block for which pacemaker was implanted 1 year back. Bilateral wrist X-ray was suggestive of pronounced demineralization (osteopenia) in the right hand. He was thus diagnosed to have reflex sympathetic dystrophy syndrome (RSDS) considered to be induced by pacemaker insertion. After treatment with amitryptiline and indomethacin his symptoms dramatically improved.

  3. Effects of brainstem lesions on the masseter inhibitory reflex. Functional mechanisms of reflex pathways

    NARCIS (Netherlands)

    Ongerboer de Visser, B. W.; Cruccu, G.; Manfredi, M.; Koelman, J. H.


    The masseter inhibitory reflex (MIR) was investigated in 16 patients with localized brainstem lesions involving the trigeminal system. The MIR consists of two phases of EMG silence (S1 and S2) evoked by stimulation of the mental nerve during maximal clenching of the teeth. The extent of the lesions

  4. Neural reflex regulation of arterial pressure in pathophysiological conditions: interplay among the baroreflex, the cardiopulmonary reflexes and the chemoreflex

    Directory of Open Access Journals (Sweden)

    E.C. Vasquez


    Full Text Available The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pressure (baroreflex, blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes, and changes in blood-gas composition (chemoreceptor reflex. The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME in which the interplay of these three reflexes is demonstrable

  5. Cough reflex sensitization from esophagus and nose (United States)

    Hennel, Michal; Brozmanova, Mariana; Kollarik, Marian


    The diseases of the esophagus and nose are among the major factors contributing to chronic cough although their role in different patient populations is debated. Studies in animal models and in humans show that afferent C-fiber activators applied on esophageal or nasal mucosa do not initiate cough, but enhance cough induced by inhaled irritants. These results are consistent with the hypothesis that activation of esophageal and nasal C-fibers contribute to cough reflex hypersensitivity observed in chronic cough patients with gastroesophageal reflux disease (GERD) and chronic rhinitis, respectively. The afferent nerves mediating cough sensitization from the esophagus are probably the neural crest-derived vagal jugular C-fibers. In addition to their responsiveness to high concentration of acid typical for gastroesophageal reflux (pHcough sensitization are less understood. Increased cough reflex sensitivity was also reported in many patients with GERD or rhinitis who do not complain of cough indicating that additional endogenous or exogenous factors may be required to develop chronic coughing in these diseases. PMID:26498387

  6. Venoarteriolar reflex responses in diabetic patients. (United States)

    Stoyneva, Z; Velcheva, I; Antonova, N; Titianova, E; Koleva, I


    The aim of this study was to investigate the venoarteriolar reflex (VAR) responses in type 1 (T1DM) and type 2 (T2DM) diabetes mellitus (DM) with polyneuropathy and to estimate their relationship with age, DM duration, initial cutaneous temperature and body mass index. Four groups of subjects were investigated: 1st group -20 patients with T1DM; 2nd group -50 patients with T2DM; 3rd group of 20 healthy subjects with similar age and body mass index (BMI) to the T1DM group; 4th group (Control2) of 24 healthy subjects adjusted by age and BMI to the T2DM group. The cutaneous perfusions of the big toe pulp were monitored as baseline perfusions at a temperature of 32°C in supine and sitting position with hanging legs and back in supine position. Loss of venoarteriolar reflex responses was established in 75% of T1DM patients, 78% of T2DM patients and in none of the investigated healthy controls. Reduced venoarteriolar perfusion responses were established in both T1DM and T2DM patients with polyneuropathy compared with healthy subjects. Reliable positive associations between VAR responses and the age, DM duration and initial cutaneous temperature were found.

  7. Wh-filler-gap dependency formation guides reflexive antecedent search

    Directory of Open Access Journals (Sweden)

    Michael eFrazier


    Full Text Available Prior studies on online sentence processing have shown that the parser can resolve non-local dependencies rapidly and accurately. This study investigates the interaction between the processing of two such non-local dependencies: wh-filler-gap dependencies (WhFGD and reflexive-antecedent dependencies. We show that reflexive-antecedent dependency resolution is sensitive to the presence of a WhFGD, and argue that the filler-gap dependency established by WhFGD resolution is selected online as the antecedent of a reflexive dependency. We investigate the processing of constructions like (1, where two NPs might be possible antecedents for the reflexive, namely which cowgirl and Mary. Even though Mary is linearly closer to the reflexive, the only grammatically licit antecedent for the reflexive is the more distant wh-NP, which cowgirl. 1. Which cowgirl did Mary expect to have injured herself due to negligence?Four eye-tracking text-reading experiments were conducted on examples like (1, differing in whether the embedded clause was non-finite (1 and 3 or finite (2 and 4, and in whether the tail of the wh-dependency intervened between the reflexive and its closest overt antecedent (1 and 2 or the wh-dependency was associated with a position earlier in the sentence (3 and 4.The results of Experiments 1 and 2 indicate the parser accesses the result of WhFGD formation during reflexive antecedent search. The resolution of a wh-dependency alters the representation that reflexive antecedent search operates over, allowing the grammatical but linearly distant antecedent to be accessed rapidly. In the absence of a long-distance WhFGD (Exp. 3 and 4, wh-NPs were not found to impact reading times of the reflexive, indicating that the parser's ability to select distant wh-NPs as reflexive antecedents crucially involves syntactic structure.

  8. Anterior segment angiography of the normal canine eye: a comparison between indocyanine green and sodium fluorescein. (United States)

    Pirie, C G; Alario, A


    The objective of this study was to assess and compare indocyanine green (IG) and sodium fluorescein (SF) angiographic findings in the normal canine anterior segment using a digital single lens reflex (dSLR) camera adaptor. Images were obtained from 10 brown-eyed Beagles, free of ocular and systemic disease. All animals received butorphanol (0.2 mg/kg IM), maropitant citrate (1.0 mg/kg SC) and diphenhydramine (2.0 mg/kg SC) 20 min prior to propofol (4 mg/kg IV bolus, 0.2 mg/kg/min continuous rate infusion). Standard color imaging was performed prior to the administration of 0.25% IG (1 mg/kg IV). Imaging was performed using a full spectrum dSLR camera, dSLR camera adaptor, camera lens (Canon 60 mm f/2.8 Macro) and an accessory flash. Images were obtained at a rate of 1/s immediately following IG bolus for 30 s, then at 1, 2, 3, 4 and 5 min. Ten minutes later, 10% SF (20 mg/kg IV) was administered. Imaging was repeated using the same adaptor system and imaging sequence protocol. Arterial, capillary and venous phases were identified during anterior segment IG angiography (ASIGA) and their time sequences were recorded. ASIGA offered improved visualization of the iris vasculature in heavily pigmented eyes compared to anterior segment SF angiography (ASSFA), since visualization of the vascular pattern during ASSFA was not possible due to pigment masking. Leakage of SF was noted in a total of six eyes. The use of IG and SF was not associated with any observed adverse events. The adaptor described here provides a cost-effective alternative to existing imaging systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Filming of zooplankton: a case study of rotifer males and Daphnia magna

    Directory of Open Access Journals (Sweden)

    Pierluigi Colangeli


    Full Text Available Filming live organisms can give new insights into the hidden life of plankton. Accessibly priced digital cameras are now available for a large range of users. Here, we demonstrate the technical setup and workflow of using a single-lens reflex (DSLR camera to film the behaviour of males of two rotifer species, Brachionus angularis Gosse (1851 and Keratella cochlearis Gosse (1851, and of the cladoceran Daphnia magna Straus (1820. Rotifers are cyclical parthenogens that produce males only under certain environmental conditions. Thus, knowledge on rotifer males is still limited because of their ephemeral nature and because they are often smaller than females. We filmed males of B. angularis and K. cochlearis with a DSLR camera connected to a compound microscope to better understand their morphology and behaviour in comparison to conspecific females. While written descriptions have their scientific value, seeing is complementary because everyone can verify what has been described. We made our videos publicly accessible through links connected to the paper. Our videos are, to our best knowledge, the first on males of B. angularis and K. cochlearis. Furthermore, we filmed the behavioural response of D. magna to ultraviolet (UV radiation with a macro lens attached to the DSLR camera. Approaches like this are valuable tools in environmental teaching. To see live organisms with one’s own eyes may contribute to raising public awareness about the value of water resources and their hidden communities. In summary, filming can be a valuable tool to ignite scientific discussion, but the videos need an open-access platform where they can be referenced in a topic-related order.

  10. Iris Pigmentation and Fractionated Reaction and Reflex Time. (United States)

    Hale, Bruce D.; And Others

    Behavioral measures, fractionated reaction and reflex times by means of electromyography, were used to determine if the eye color differences are found in the central or peripheral regions of the nervous system. The purpose of this research was to determine the truth of the hypothesis that dark-eyed individuals have faster reflex and reaction time…

  11. Low Incidence Of Extensor Plantar Reflex In Newborns In An ...

    African Journals Online (AJOL)

    Healthy term newborns with Apgar score of 8 and above at one minute were recruited into the study consecutively in a maternity hospital in Ibadan, Nigeria. The plantar reflex was elicited by stroking the lateral side of the sole with firm pressure, between 24 - 48 hours after delivery. Results Of 461 newborns, the plantar reflex ...

  12. On the Property of Reflexivity for Multiplication Operators on Banach ...

    Indian Academy of Sciences (India)


    operator Mz are reflexive on a Banach space of functions analytic on a plane domain. AMS Subject Classification: 47B37; 46A25. Keywords: Banach spaces of analytic functions, multiplication operators, reflexive oper- ator, multipliers, Caratheodory hull, bounded point evaluation, spectral set. Introduction. For any set E and ...

  13. Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity. (United States)

    Farrugia, David; Woodman, Dan


    Through a critique of Margaret Archer's theory of reflexivity, this paper explores the theoretical contribution of a Bourdieusian sociology of the subject for understanding social change. Archer's theory of reflexivity holds that conscious 'internal conversations' are the motor of society, central both to human subjectivity and to the 'reflexive imperative' of late modernity. This is established through critiques of Bourdieu, who is held to erase creativity and meaningful personal investments from subjectivity, and late modernity is depicted as a time when a 'situational logic of opportunity' renders embodied dispositions and the reproduction of symbolic advantages obsolete. Maintaining Archer's focus on 'ultimate concerns' in a context of social change, this paper argues that her theory of reflexivity is established through a narrow misreading and rejection of Bourdieu's work, which ultimately creates problems for her own approach. Archer's rejection of any pre-reflexive dimensions to subjectivity and social action leaves her unable to sociologically explain the genesis of 'ultimate concerns', and creates an empirically dubious narrative of the consequences of social change. Through a focus on Archer's concept of 'fractured reflexivity', the paper explores the theoretical necessity of habitus and illusio for understanding the social changes that Archer is grappling with. In late modernity, reflexivity is valorized just as the conditions for its successful operation are increasingly foreclosed, creating 'fractured reflexivity' emblematic of the complex contemporary interaction between habitus, illusio, and accelerating social change. © London School of Economics and Political Science 2015.

  14. [The development of I. P. Pavlov's conditioned reflex theory]. (United States)

    Kim, O J


    This paper deals with the theory of Ivan Petrovich Pavlov (1849-1936), a Russian physiologist who presented for the first time the systematic theory of the function of the brain that controls the whole behavior of animals, i.e. higher nervous activity through experimental studies. This paper, principally based on Lectures on Conditioned Reflexes (1928), investigates the development of conditioned reflex theory from its beginning by dividing it into three periods. First, during the period from 1898 to 1906, the fundamental concept of conditioned reflex was established and the study of conditioned reflex became an independent discipline. From 1907 to 1916, the second period, Pavlov theorized on higher nervous activity on the basis of extensive data from his laboratory experiments of conditioned reflex. And Pavlov complemented conditioned reflex theory, during the third period from 1916 to 1928, and extended the boundaries of it through applications of conditioned reflex theory to psychopathology and typology. The study contributes to the understanding that conditioned reflex theory was historically developed, and not presented as a complete form from the beginning, and that Pavlov intended to study the higher nervous activity through the method of neurophysiology.

  15. Lemmatization of reflexives in Northern Sotho | Prinsloo | Lexikos

    African Journals Online (AJOL)

    The aim of this article is to evaluate current strategies in the lemmatization of reflexives in Northern Sotho. In particular the so-called "traditional" approach according to which reflexives are lemmatized randomly, as well as the more "rule orientated" alternative, will be critically evaluated mainly against the background of ...

  16. Reflexivity as a control factor of personal coping behavior




    The article deals with the issue of coping behavior control. The author defines the criteria, levels and aspects of reflexivity within the framework of personal coping behavior. In conclusion the author describes the key facets of coping behavior control and how reflexivity affects them.

  17. Epithelioid sarcoma presenting as the reflex sympathetic dystrophy syndrome. (United States)

    Summers, C. L.; Shahi, M.


    A case of reflex sympathetic dystrophy caused by an epithelioid sarcoma is presented. This is the first report of a local peripheral tumour associated with the reflex sympathetic dystrophy syndrome. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:3671265

  18. Reflex sympathetic dystrophy: Early treatment and psychological aspects

    NARCIS (Netherlands)

    Geertzen, J.H.B.; De Bruijn, H.; De Bruijn-Kofman, A.T.; Arendzen, J.H.


    We report the results of two prospective studies of early treatment and psychological aspects in a series of 26 patients with sympathetic reflex dystrophy of the hand in which treatment was started within 3 months after diagnosis. Ismelin blocks is an often used therapy in sympathetic reflex

  19. 21 CFR 890.1450 - Powered reflex hammer. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hammer. (a) Identification. A powered reflex hammer is a motorized device intended for medical purposes...

  20. A Critical Reflexive Perspective on Othering in Collaborative Knowledge Production

    DEFF Research Database (Denmark)

    Nordentoft, Helle Merete; Olesen, Birgitte Ravn


    -reflexive analyses of reflexive processes within collaborative knowledge production We use an analytical framework combining Bakhtin and Foucault to investigate processes of inclusion and exclusion in the interplay between dominant and subordinated voices in a moment-by-moment analysis of two incidents from...... interdisciplinary workshops. Findings The analysis illuminates how differences between voices challenge participants’ reflexive awareness and lead to the reproduction of contextual power and knowledge hierarchies and the concomitant silencing of particular participants. Thus, the findings draw attention...... to the complex and ethical nature of collaborative knowledge production. Practical implications To invite researchers to be reflexive about the complex, situated and emergent character of reflexive processes and consider ethics to be a critical stance that encourages continuous reflection and critique...

  1. Stretch reflex regulation in healthy subjects and patients with spasticity

    DEFF Research Database (Denmark)

    Nielsen, Jens Bo; Petersen, Nicolas; Crone, Clarissa


    In recent years, part of the muscle resistance in spastic patients has been explained by changes in the elastic properties of muscles. However, the adaptive spinal mechanisms responsible for the exaggeration of stretch reflex activity also contribute to muscle stiffness. The available data suggest...... of the spastic symptoms. A recent finding also shows no sign of exaggerated stretch reflexes in muscles voluntarily activated by the spastic patient in general. This is easily explained by the control of stretch reflex activity in healthy subjects. In healthy subjects, the stretch reflex activity is increased...... movements, antagonist muscles should remain silent and maximally relaxed. This is ensured by increasing transmission in several spinal inhibitory pathways. In spastic patients, this control is inadequate, and therefore stretch reflexes in antagonist muscles are easily evoked at the beginning of voluntary...

  2. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O


    sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno......Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human...... skeletal muscle, cutaneous and subcutaneous tissues of the limbs indicate that the situation is more complex. Measurements have been carried out during acute as well as chronic sympathetic denervation. Spinal sympathetic reflex mechanisms have been evaluated in tetraplegic patients, where supraspinal...

  3. Prevalence of family history in patients with reflex syncope

    DEFF Research Database (Denmark)

    Holmegard, Haya N; Benn, Marianne; Kaijer, Michelle Nymann


    among subtypes of reflex syncope, as these have different autonomic responses and pathogeneses may be diverse. The present study aimed to assess the prevalence of a positive family history of syncope and cardiovascular characteristics in patients with cardioinhibitory and vasodepressor reflex syncope......Reflex syncope is defined by a rapid transient loss of consciousness caused by global cerebral hypoperfusion resulting from vasodilatation and/or bradycardia attributable to inappropriate cardiovascular reflexes. A hereditary component has been suggested, but prevalence of family history may differ....... Patients (n=74) were classified into subtypes of reflex syncope - cardioinhibition/asystole (Vasovagal Syncope International Study subtypes II-B [VASIS II-B], n=38) or vasodepressor (VASIS III, n=36) - using the head-up tilt test. Family history was obtained by questionnaires supplemented by interview...

  4. Voluntary Control of the Near Reflex: A Case Report

    Directory of Open Access Journals (Sweden)

    Serpil Akar


    Full Text Available Spasm of the near reflex is a rare disorder that involves intermittent and variable episodes of esotropia, pseudomyopia, and pupillary myosis. It is usually functional in origin and is seen mainly in young patients. Treatment options for spasm of the near reflex have had variable success. In instances where the etiology of spasm of the near reflex was suspected to be hysteria, psychotherapy has proven beneficial. We report the case of an 11-year-old girl who had functional spasm of the near reflex. The symptoms persisted for two years. Symptomatic relief was achieved by cycloplegia and spectacle correction (added plus lenses at near. The patient also underwent psychological counseling. In our case, the functional spasm of the near reflex spontaneously resolved after 2 years. (Turk J Ophthalmol 2014; 44: 161-3

  5. Reflexive regulation of CSR to promote sustainablility

    DEFF Research Database (Denmark)

    Buhmann, Karin

    This article discusses Corporate Social Responsibility (CSR) from the perspective of governmental regulation as a measure to promote public policy interests through public-private regulation intended to influence firms’ self-regulation. Presenting a ‘government case’ for CSR, the connection between...... in order to balance power disparities among participants. Finally, the analysis suggests that a juridification of CSR is taking place. This development is welcome because legal theory and scholarship’s insight into institutionalisation of norms of conduct has much to offer to society’s interests...... in promoting companies’ responsibility with regard to aspects of sustainable development, such as climate impact. Keywords: Sustainable development, sustainable companies, reflexive regulation, climate change, CSR, EU law, public-private regulation, companies' self-regulation...

  6. Reflexive regulation of CSR to promote sustainability

    DEFF Research Database (Denmark)

    Buhmann, Karin


    This article discusses Corporate Social Responsibility (CSR) from the perspective of governmental regulation as a measure to promote public policy interests through public-private regulation intended to influence firms’ self-regulation. Presenting a ‘government case’ for CSR, the connection between...... and the EU CSR Alliance. Focusing on human rights based in international law, it analyses the patterns of negotiation in the MSF and the background for the launch of the CSR Alliance. It shows that analysing public-private regulation of CSR from the perspective of reflexive law theory assists us...... climate change and environmental sustainability, and social, economic and other human rights lend human rights as part of CSR a potential for meeting some environmental and climate concerns and handling adverse side-effects. The article analyses two EU initiatives: The EU Multi-Stakeholder (MSF) on CSR...

  7. Study of the Reflex-Klystron

    International Nuclear Information System (INIS)

    Valencia A, R.


    The main purpose of this paper is the theoretical study and the development of a technique for designing. A low power Reflex-Klystron, in order to construct it in the graduated section laboratories of the Instituto Politecnico Nacional. It is pretended to attain a power of 15-45 m W in frequencies of 8-10 GHz with low acceleration potentials (300-400 V) and electric current of 15-25 m A; the device will be mechanically tuned and will have a fine tuning through the potential of the reflector (150-180 V negative with respect to the resonator). The International System of Units is used in this thesis. (Author)

  8. Analysing responses to climate change through the lens of reflexivity. (United States)

    Davidson, Debra


    Sociologists are increasingly directing attention toward social responses to climate change. As is true of any new field of inquiry, theoretical frameworks guiding the research to date have room for improvement. One advance could be achieved through closer engagement with Reflexivity Theory, particularly the work of Margaret Archer, who asks just how individuals come to give attention to certain problems, and formulate responses to them. Individuals vary significantly in regard to their understanding of and concern for anthropogenic climate change, and these standpoints in turn influence commitment to mitigation and adaptation. The emergent social interactions among all such agents in turn influence the morphogenetic trajectories through which social structures will evolve, but the role of 'meta-reflexives' is particularly crucial. Identifying pathways of individual climate change reflexivity can make a valuable contribution to our understanding of the potential for and nature of collective responses. In this paper, I explore climate change reflexivity, with particular attention to climate change meta-reflexives, through a qualitative analysis of personal interviews with residents of two small communities in Alberta, Canada. Applying Reflexivity Theory to this context articulates dimensions of reflexive processing not elaborated in current theoretical treatments, including future outlook and comfort with uncertainty, among others. © London School of Economics and Political Science 2012.

  9. [Human physiology: images and practices of the reflex]. (United States)

    Wübben, Yvonne


    The essay examines the function of visualizations and practices in the formation of the reflex concept from Thomas Willis to Marshall Hall. It focuses on the specific form of reflex knowledge that images and practices can contain. In addition, the essay argues that it is through visual representations and experimental practices that technical knowledge is transferred to the field of human reflex physiology. When using technical metaphors in human physiology authors often seem to feel obliged to draw distinctions between humans, machines and animals. On closer scrutiny, these distinctions sometimes fail to establish firm borders between the human and the technical.

  10. Flexion Reflex Can Interrupt and Reset the Swimming Rhythm. (United States)

    Elson, Matthew S; Berkowitz, Ari


    The spinal cord can generate the hip flexor nerve activity underlying leg withdrawal (flexion reflex) and the rhythmic, alternating hip flexor and extensor activities underlying locomotion and scratching, even in the absence of brain inputs and movement-related sensory feedback. It has been hypothesized that a common set of spinal interneurons mediates flexion reflex and the flexion components of locomotion and scratching. Leg cutaneous stimuli that evoke flexion reflex can alter the timing of (i.e., reset) cat walking and turtle scratching rhythms; in addition, reflex responses to leg cutaneous stimuli can be modified during cat and human walking and turtle scratching. Both of these effects depend on the phase (flexion or extension) of the rhythm in which the stimuli occur. However, similar interactions between leg flexion reflex and swimming have not been reported. We show here that a tap to the foot interrupted and reset the rhythm of forward swimming in spinal, immobilized turtles if the tap occurred during the swim hip extensor phase. In addition, the hip flexor nerve response to an electrical foot stimulus was reduced or eliminated during the swim hip extensor phase. These two phase-dependent effects of flexion reflex on the swim rhythm and vice versa together demonstrate that the flexion reflex spinal circuit shares key components with or has strong interactions with the swimming spinal network, as has been shown previously for cat walking and turtle scratching. Therefore, leg flexion reflex circuits likely share key spinal interneurons with locomotion and scratching networks across limbed vertebrates generally. The spinal cord can generate leg withdrawal (flexion reflex), locomotion, and scratching in limbed vertebrates. It has been hypothesized that there is a common set of spinal cord neurons that produce hip flexion during flexion reflex, locomotion, and scratching based on evidence from studies of cat and human walking and turtle scratching. We show

  11. Leg muscle reflexes mediated by cutaneous A-beta fibres are normal during gait in reflex sympathetic dystrophy. (United States)

    van der Laan, L; Boks, L M; van Wezel, B M; Goris, R J; Duysens, J E


    Reflex sympathetic dystrophy (RSD) is, from the onset, characterized by various neurological deficits such as an alteration of sensation and a decrease in muscle strength. We investigated if afferent A-beta fibre-mediated reflexes are changed in lower extremities affected by acute RSD. The involvement of these fibres was determined by analyzing reflex responses from the tibialis anterior (TA) and biceps femoris (BF) muscles after electrical stimulation of the sural nerve. The reflexes were studied during walking on a treadmill to investigate whether the abnormalities in gait of the patients were related either to abnormal amplitudes or deficient phase-dependent modulation of reflexes. In 5 patients with acute RSD of the leg and 5 healthy volunteers these reflex responses were determined during the early and late swing phase of the step cycle. No significant difference was found between the RSD and the volunteers. During early swing the mean amplitude of the facilitatory P2 responses in BF and TA increased as a function of stimulus intensity (1.5, 2 and 2.5 times the perception threshold) in both groups. At end swing the same stimuli induced suppressive responses in TA. This phase-dependent reflex reversal from facilitation in early swing to suppression in late swing occurred equally in both groups. In the acute phase of RSD of the lower extremity there is no evidence for abnormal A-beta fibre-mediated reflexes or for defective regulation of such reflexes. This finding has implications for both the theory on RSD pathophysiology and RSD models, which are based on abnormal functioning of A-beta fibres.

  12. Plasticity of the cervico-ocular reflex in health and Disease

    NARCIS (Netherlands)

    W.P.A. Kelders (Willem)


    textabstractThe cervico-ocular reflex (COR) is an ocular stabilization reflex that is elicited by rotation of the neck. It works in conjunction with the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) in order to prevent visual slip over the retina due to self motion. The VOR

  13. Compensatory increase of the cervico-ocular reflex with age in healthy humans.

    NARCIS (Netherlands)

    W.P.A. Kelders (Willem); G.J. Kleinrensink (Gert Jan); J.N. van der Geest (Jos); L. Feenstra (Louw); C.I. de Zeeuw (Chris); M.A. Frens (Maarten)


    textabstractThe cervico-ocular reflex (COR) is an ocular stabilization reflex that is elicited by rotation of the neck. It works in conjunction with the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) in order to prevent visual slip over the retina due to

  14. Interindividual differences in H reflex modulation during normal walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Dyhre-Poulsen, Poul; Alkjaer, T


    Based on previous studies, at least two different types of soleus Hoffmann (H) reflex modulation were likely to be found during normal human walking. Accordingly, the aim of the present study was to identify different patterns of modulation of the soleus H reflex and to examine whether...... or not subjects with different H reflex modulation would exhibit different walking mechanics and different EMG activity. Fifteen subjects walked across two force platforms at 4.5 km/h (+/-10%) while the movements were recorded on video. The soleus H reflex and EMG activity were recorded separately during...... treadmill walking at 4.5 km/h. Using a two-dimensional analysis joint angles, angular velocities, accelerations, linear velocities and accelerations were calculated, and net joint moments about the ankle, knee and hip joint were computed by inverse dynamics from the video and force plate data. Six subjects...

  15. Non-reflexive Logical Foundation for Quantum Mechanics (United States)

    da Costa, N. C. A.; de Ronde, C.


    On the one hand, non-reflexive logics are logics in which the principle of identity does not hold in general. On the other hand, quantum mechanics has difficulties regarding the interpretation of `particles' and their identity, also known in the literature as `the problem of indistinguishable particles'. In this article, we will argue that non-reflexive logics can be a useful tool to account for such quantum indistinguishability. In particular, we will provide a particular non-reflexive logic that can help us to analyze and discuss this problem. From a more general physical perspective, we will also analyze the limits imposed by the orthodox quantum formalism to consider the existence of indistinguishable particles in the first place, and argue that non-reflexive logics can also help us to think beyond the limits of classical identity.

  16. Pseudodystrophy. A conversion disorder mimicking reflex sympathetic dystrophy. (United States)

    Driessens, M; Blockx, P; Geuens, G; Dijs, H; Verheyen, G; Stassijns, G


    The authors suggest some criteria by which pseudodystrophy and reflex sympathetic dystrophy, although sharing some similar clinical features, can be distinguished as two different conditions, each requiring its own approach and management. The most important distinction is found on bone scintigraphy. In reflex sympathetic dystrophy the bone scan shows a typical increased tracer uptake (at least during stages I and II); in pseudodystrophy there is a normal or decreased tracer uptake in the affected region. Moreover the vascularization is increased in reflex sympathetic dystrophy stage I, whereas in pseudodystrophy hypovascularization is found from the beginning. The clinical features, as well as the results of technical investigations, psychological evaluation and treatment of 4 patients with pseudodystrophy are presented. The importance of distinguishing this condition from reflex sympathetic dystrophy is stressed.

  17. Sympathetic skin responses in reflex sympathetic dystrophy. (United States)

    Bolel, K; Hizmetli, S; Akyüz, A


    This study was performed to determine the utility of sympathetic skin response (SSR) in evaluating the sympathetic function and to follow up the effects of sympathetic blockade in reflex sympathetic dystrophy (RSD). Thirty patients having RSD with upper extremity involvement were randomly divided into two groups. Besides medical therapy and exercise, physical therapy agents were applied to both the groups. In addition to this treatment protocol, stellar ganglion blockade was done by diadynamic current in Group II. The normal sides of the patients were used for the control group. SSRs were measured in all the patients before and after the therapy. The amplitude was found to be increased and the latency was found to be decreased in the affected side in both the groups before the therapy. After the therapy, the amplitude was decreased and latency was increased in both the groups. But, the differences in amplitude (P = 0.001) and latency (P = 0.002) before and after the therapy were significantly higher in Group II. (Before the treatment, SSRs were significantly different between the normal and the affected sides in both the groups. The observed change in SSRs after the treatment was higher in Group II.) It was concluded that, SSR can be a useful and noninvasive method in diagnosing the sympathetic dysfunction in RSD and can be used for evaluating the response to sympathetic blockade and other treatment modalities.

  18. Reflex sympathetic dystrophy syndrome and neuromediators. (United States)

    Pham, Thao; Lafforgue, Pierre


    Concepts related to the pathophysiology of reflex sympathetic dystrophy syndrome (RSDS) are changing. Although sympathetic influences are still viewed as the most likely mechanism underlying the development and/or perpetuation of RSDS, these influences are no longer ascribed to an increase in sympathetic tone. Rather, the most likely mechanism may be increased sensitivity to catecholamines due to sympathetic denervation with an increase in the number and/or sensitivity of peripheral axonal adrenoceptors. Several other pathophysiological mechanisms have been suggested, including neurogenic inflammation with the release of neuropeptides by primary nociceptive afferents and sympathetic efferents. These neuromediators, particularly substance P, calcitonin gene-related peptide, and neuropeptide Y (NPY), may play a pivotal role in the genesis of pain in RSDS. They induce an inflammatory response (cutaneous erythema and edema) and lower the pain threshold. Neurogenic inflammation at the site of the lesion with neuromediator accumulation or depletion probably contributes to the pathophysiology of RSDS. However, no single neuromediator has been proved responsible, and other hypotheses continue to arouse interest.

  19. Blink reflexes in patients with atypical odontalgia. (United States)

    Baad-Hansen, Lene; List, Thomas; Jensen, Troels Staehelin; Leijon, Göran; Svensson, Peter


    To use the human blink reflex (BR) to explore possible neuropathic pain mechanisms in patients with atypical odontalgia (AO). In 13 AO patients, the BR was elicited using a concentric electrode and recorded bilaterally with surface electromyographic (EMG) electrodes on both orbicularis oculi muscles. Electrical stimuli were applied to the skin above branches of the V1, V2, and V3 nerves and to the V branch contralateral to the painful branch. Sensory and pain thresholds were determined. The BR examination of the painful V branch was repeated during a capsaicin pain-provocation test. The data were analyzed with nonparametric statistics. The BR responses (R2 and R3) evoked by stimulation of V3 were significantly smaller than the BR responses evoked by stimulation of V1 and V2 (P .569), and the BR (R2 and R3) was not significantly modulated by experimental pain (P > .080). The sensory thresholds were significantly lower on the painful side compared to the nonpainful side (P = .014). The pain thresholds were not different between sides (P > .910). No major differences between the V nociceptive pathways on the right and left sides were found in a relatively small group of AO patients. Future studies that compare BRs in AO patients and healthy volunteers are needed to provide further knowledge on the pain mechanisms in AO.

  20. Cough reflex hypersensitivity: A role for neurotrophins. (United States)

    El-Hashim, Ahmed Z; Jaffal, Sahar M


    Cough is one of the most common complaints for which sufferers seek medical assistance. However, currently available drugs are not very effective in treating cough, particularly that which follows an upper respiratory tract infection. Nonetheless, there has been a significant increase in our understanding of the mechanisms and pathways of the defensive cough as well as the hypersensitive/pathophysiological cough, both at airway and central nervous system (CNS) levels. Numerous molecules and signaling pathways have been identified as potential targets for antitussive drugs, including neurotrophins (NTs). NTs belong to a family of trophic factors and are critical for the development and maintenance of neurons in the central and peripheral nervous system including sympathetic efferents, sensory neuron afferents, and immune cells. Nerve growth factor (NGF) was the first member of the NT family to be discovered, with wide ranging actions associated with synapse formation, survival, proliferation, apoptosis, axonal and dendritic outgrowth, expression and activity of functionally important proteins such as ion channels, receptors, and neurotransmitters. In addition, NGF has been implicated in several disease states particularly neuropathic pain and most recently in the sensitization of the cough reflex. This review will briefly address the peripheral and central sensitization mechanisms of airway neurons and will then focus on NGF signaling and its role in cough hypersensitivity.

  1. Mechanical Characteristics of Reflex Durign Upright Posture in Paralyzed Subjects (United States)

    Kim, Yongchul; Youm, Youngil; Lee, Bumsuk; Kim, Youngho; Choi, Hyeonki

    The characteristics of flexor reflexes have been investigated in the previous studies with human subjects who were seated or supine position. However, researchers did not describe how the spinal circuits are used in different hip angles for paralyzed subjects, such as the standing position with walker or cane. In upright posture the compatibility between a flexor reflex of leg and body balance is a special problem for lower limb injured subjects. Therefore, the purpose of this study was to investigate the effects of hip angle change on the flexor reflex evoked in standing paralyzed subjects supported by walker. In this study, six spinal cord injured and four stroke subjects were recruited through the inpatient physical therapy clinics of Korea national rehabilitation hospital. A single axis electronic goniometer was mounted on the lateral side of the hip joint of the impaired limb to record movements in the sagittal plane at this joint. The electronic goniometer was connected to a data acquisition system, through amplifiers to a computer. Since subject' posture influenced characteristics of the flexion reflex response, the subjects were supported in an upright posture by the help of parallelogram walder. Two series of tests were performed on each leg. The first series of the tests investigated the influence of hip angle during stationary standing posture on flexion reflex response. The hip angle was adjusted by the foot plate. The second examined the effect of the voluntary action of subject on swing motion during the gait. The electrically induced flexion reflex simultaneously produced the flexion of the hip, knee and dorsiflexion of the ankle enabling the swing phase of walking. Form the experimental results we observed that the reflex response of hip joint was largerwith the hip in the extended position than in the flexed position during standing posture. Under voluntary movement on flexion reflex during gaint, the peak hip angle induced by stimulation was

  2. Reflexive Pronouns in Dagbani Samuel Alhassan Issah1 Abstract ...

    African Journals Online (AJOL)

    between a reflexive and its antecedent is accounted for using c-command. Haegeman (1994:212) claims that a node A c-commands a node B if (1) A does not dominate B; (2) B does not dominate A; and ..... reflexive o-maŋa “himself” has the subject of the embedded clause Abu as its antecedent. These two arguments, Abu ...

  3. Intranasal Midazolam May Prevent Gagging Reflex: a Case Report


    Malkoc, Meral Arslan; Demir, Necla; Ileri, Zehra; Erdur, Aybuke; Apiliogullari, Seza


    ABSTRACT Background Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old) with exaggerated gag reflex referred to Faculty of Dentistry of Selçuk University. Methods During obtaining records, taking impression procedure was elicited the patients’ hypersensitive gagging reflex. Therefore, it was decided to administer intr...

  4. [Reflexive education in post-modernity: a bibliographic review]. (United States)

    Gomes, Jomara Brandini; Casagrande, Lisete Diniz Ribas


    This is a bibliographical review that aimed at considering teaching at the actual historical moment, denominated post-modernity, and that has resulted in a pragmatic change in all levels of human being understanding. Thus, authors rescued and presented the presuppositions for a post-modern education, emphasizing among them the reflexive education proposed by Donald A. Shön, that is based on practical learning centered in "reflexion-in-action", as an alternative for the formation of a reflexive professional.

  5. Avian reflex and electroencephalogram responses in different states of consciousness. (United States)

    Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F


    Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Student Mobility and Transnational Social Ties as Factors of Reflexivity

    Directory of Open Access Journals (Sweden)

    Tea Golob


    Full Text Available The article seeks to develop and apply new quantitative measurement instruments capable of significantly improving understanding of the relationship between the transnational mobility and transnational social ties of students, along with their reflexive capacities. With a focus on students building their personal networks, educational and professional activities that extend beyond the nation’s borders and organising their day-to-day routines in transnational social spaces, we analyse the role of mobility in their reflexive capacities. Applying a tool that is line with Archer’s theory and indicators to measure reflexivity, and transnational social ties as proposed by Molina et al., we analyse data collected via an on-line survey questionnaire administered to Slovenian students. In addition, students from the Middle East (Lebanon and the USA (Hawai’i are added for comparative purposes. The results of path analysis show the Slovenian students’ mobility as such implies higher scores for meta reflexivity, combined with lower scores for communicative and fractured reflexivity. Further, social transactions reaching beyond one’s physical localities in terms of transnational social ties implies they have higher levels of reflexivity in general.

  7. Doppler sonographic assessment of posttraumatic reflex sympathetic dystrophy. (United States)

    Pekindil, Gökhan; Pekindil, Yesim; Sarikaya, Ali


    To reveal the arterial Doppler sonographic findings in cases of posttraumatic reflex sympathetic dystrophy Eleven patients had hand reflex sympathetic dystrophy, and 9 had foot reflex sympathetic dystrophy. The duration of symptoms ranged from 1 to 28 weeks, and the history of fracture ranged from 6 to 48 weeks. Bilateral brachial or popliteal arteries proximal to injuries were evaluated by Doppler sonography with a 7.5-MHz linear transducer. All patients also had triphasic bone scintigraphy and extremity thermography Two patients had monophasic waveforms and 4 had low-pulsatility triphasic waveforms on the affected limbs when compared with the asymptomatic limbs. All opposite asymptomatic limbs had normal triphasic waveforms in these 6 cases. Spectral analysis revealed a loss or decrease of a normal reversed flow component with a reduced pulsatility index on the affected limb. Fourteen other patients had symmetric triphasic waveforms. We observed that the patients who had stage 1 reflex sympathetic dystrophy and warm limbs with durations of symptoms of more than 2 weeks had positive Doppler sonographic findings, whereas all patients with stage 2 reflex sympathetic dystrophy and all with normal skin temperature, regardless of stage, had normal waveforms. Doppler sonography revealed loss of normal triphasic arterial waveforms in some of the cases of stage 1 disease, whereas many cases of stage 1 disease and all cases of stage 2 disease had normal findings. Therefore, we think that Doppler sonography cannot be used for the diagnosis of reflex sympathetic dystrophy but may help in assessing hemodynamic stages of the disease.

  8. A method of reflexive balancing in a pragmatic, interdisciplinary and reflexive bioethics. (United States)

    Ives, Jonathan


    In recent years there has been a wealth of literature arguing the need for empirical and interdisciplinary approaches to bioethics, based on the premise that an empirically informed ethical analysis is more grounded, contextually sensitive and therefore more relevant to clinical practice than an 'abstract' philosophical analysis. Bioethics has (arguably) always been an interdisciplinary field, and the rise of 'empirical' (bio)ethics need not be seen as an attempt to give a new name to the longstanding practice of interdisciplinary collaboration, but can perhaps best be understood as a substantive attempt to engage with the nature of that interdisciplinarity and to articulate the relationship between the many different disciplines (some of them empirical) that contribute to the field. It can also be described as an endeavour to explain how different disciplinary approaches can be integrated to effectively answer normative questions in bioethics, and fundamental to that endeavour is the need to think about how a robust methodology can be articulated that successfully marries apparently divergent epistemological and metaethical perspectives with method. This paper proposes 'Reflexive Bioethics' (RB) as a methodology for interdisciplinary and empirical bioethics, which utilizes a method of 'Reflexive Balancing' (RBL). RBL has been developed in response to criticisms of various forms of reflective equilibrium, and is built upon a pragmatic characterization of Bioethics and a 'quasi-moral foundationalism', which allows RBL to avoid some of the difficulties associated with RE and yet retain the flexible egalitarianism that makes it intuitively appealing to many. © 2013 John Wiley & Sons Ltd.

  9. Bisphosphonate therapy of reflex sympathetic dystrophy syndrome (United States)

    Adami, S; Fossaluzza, V; Gatti, D; Fracassi, E; Braga, V


    OBJECTIVE—The reflex sympathetic dystrophy syndrome (RSDS) is a painful limb disorder, for which a consistently effective treatment has not yet been identified. The disease is associated with increased bone resorption and patchy osteoporosis, which might benefit from treatment with bisphosphonates, powerful inhibitors of bone resorption.
METHODS—Twenty patients with RSDS of foot and hand, were randomly assigned to blind administration of either alendronate intravenously (Istituto Gentili, Pisa, Italy) 7.5 mg dissolved in 250 ml saline solution or placebo saline infusions daily for three days. Two weeks later all patients had an identical treatment course with open labelled alendronate (7.5 mg/day for three days), independent from the results of the first blind treatment.
RESULTS—In the patients treated with blind alendronate the diminution in spontaneous pain, tenderness, and swelling (circumference of the affected limb) and the improvement in motion were significantly different from baseline (p<0.001), from those observed within the first two weeks in the control group (p<0.01), and from week 2 to week 4 (p<0.01). In the patients given blind placebo infusions no relevant symptomatic changes were observed after the first two weeks of follow up, but they responded to the open alendronate therapy given afterwards. In 12 patients with RSDS of the hand the ultradistal bone mineral content (BMC) of the affected arm was considerably lower than that of the controlateral arm (mean (SD)) (426(82) mg/cm versus 688(49)). Six weeks after the beginning of the trial BMC rose by 77(12) mg/cm (p<0.001) in the affected arm, but it did not change in the controlateral.
CONCLUSIONS—These results indicate that bisphosphonates should be considered for the treatment of RSDS, producing consistent and rapid remission of the disease.


  10. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

    Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.


    Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

  11. Can Treadmill Perturbations Evoke Stretch Reflexes in the Calf Muscles? (United States)

    Sloot, Lizeth H; van den Noort, Josien C; van der Krogt, Marjolein M; Bruijn, Sjoerd M; Harlaar, Jaap


    Disinhibition of reflexes is a problem amongst spastic patients, for it limits a smooth and efficient execution of motor functions during gait. Treadmill belt accelerations may potentially be used to measure reflexes during walking, i.e. by dorsal flexing the ankle and stretching the calf muscles, while decelerations show the modulation of reflexes during a reduction of sensory feedback. The aim of the current study was to examine if belt accelerations and decelerations of different intensities applied during the stance phase of treadmill walking can evoke reflexes in the gastrocnemius, soleus and tibialis anterior in healthy subjects. Muscle electromyography and joint kinematics were measured in 10 subjects. To determine whether stretch reflexes occurred, we assessed modelled musculo-tendon length and stretch velocity, the amount of muscle activity, as well as the incidence of bursts or depressions in muscle activity with their time delays, and co-contraction between agonist and antagonist muscle. Although the effect on the ankle angle was small with 2.8±1.0°, the perturbations caused clear changes in muscle length and stretch velocity relative to unperturbed walking. Stretched muscles showed an increasing incidence of bursts in muscle activity, which occurred after a reasonable electrophysiological time delay (163-191 ms). Their amplitude was related to the muscle stretch velocity and not related to co-contraction of the antagonist muscle. These effects increased with perturbation intensity. Shortened muscles showed opposite effects, with a depression in muscle activity of the calf muscles. The perturbations only slightly affected the spatio-temporal parameters, indicating that normal walking was retained. Thus, our findings showed that treadmill perturbations can evoke reflexes in the calf muscles and tibialis anterior. This comprehensive study could form the basis for clinical implementation of treadmill perturbations to functionally measure reflexes during

  12. Can Treadmill Perturbations Evoke Stretch Reflexes in the Calf Muscles?

    Directory of Open Access Journals (Sweden)

    Lizeth H Sloot

    Full Text Available Disinhibition of reflexes is a problem amongst spastic patients, for it limits a smooth and efficient execution of motor functions during gait. Treadmill belt accelerations may potentially be used to measure reflexes during walking, i.e. by dorsal flexing the ankle and stretching the calf muscles, while decelerations show the modulation of reflexes during a reduction of sensory feedback. The aim of the current study was to examine if belt accelerations and decelerations of different intensities applied during the stance phase of treadmill walking can evoke reflexes in the gastrocnemius, soleus and tibialis anterior in healthy subjects. Muscle electromyography and joint kinematics were measured in 10 subjects. To determine whether stretch reflexes occurred, we assessed modelled musculo-tendon length and stretch velocity, the amount of muscle activity, as well as the incidence of bursts or depressions in muscle activity with their time delays, and co-contraction between agonist and antagonist muscle. Although the effect on the ankle angle was small with 2.8±1.0°, the perturbations caused clear changes in muscle length and stretch velocity relative to unperturbed walking. Stretched muscles showed an increasing incidence of bursts in muscle activity, which occurred after a reasonable electrophysiological time delay (163-191 ms. Their amplitude was related to the muscle stretch velocity and not related to co-contraction of the antagonist muscle. These effects increased with perturbation intensity. Shortened muscles showed opposite effects, with a depression in muscle activity of the calf muscles. The perturbations only slightly affected the spatio-temporal parameters, indicating that normal walking was retained. Thus, our findings showed that treadmill perturbations can evoke reflexes in the calf muscles and tibialis anterior. This comprehensive study could form the basis for clinical implementation of treadmill perturbations to functionally

  13. The babkin reflex in infants: clinical significance and neural mechanism. (United States)

    Futagi, Yasuyuki; Yanagihara, Keiko; Mogami, Yukiko; Ikeda, Tae; Suzuki, Yasuhiro


    There have been very few studies concerning the Babkin reflex-opening of the mouth and flexion of the arms in response to stimulation of the palms. We attempted to clarify the clinical significance and neural mechanism of the reflex through systematic review. Searches were conducted on Medline, Embase, and Google Scholar from their inception through August 2012. In normal term infants, the Babkin reflex can be elicited from the time of birth, becomes increasingly suppressed with age, and disappears in the great majority by the end of the fifth month of age. A marked response in the fourth or fifth month of age and persistence of the reflex beyond the fifth month of age are generally regarded as abnormal. On the other hand, because there are some normal infants showing no response during the neonatal period or early infancy, the absence of the response during these periods is not necessarily an abnormal finding. Infants with these abnormal findings should be carefully observed for the appearance of neurological abnormalities including cerebral palsy and mental retardation. It is most likely that the Babkin reflex is mediated by the reticular formation of the brainstem, which receives inputs from the nonprimary motor cortices. On the basis of the hand-mouth reflex, more adaptive movement develops as control of the nonprimary motor cortices over the reflex mechanism in the reticular formation increases. Soon it evolves into the voluntary eye-hand-mouth coordination necessary for food intake as the control of the prefrontal cortex over the nonprimary motor cortices becomes predominant. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. The role of the superior laryngeal nerve in esophageal reflexes (United States)

    Medda, B. K.; Jadcherla, S.; Shaker, R.


    The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not

  15. Trigeminal cardiac reflex and cerebral blood flow regulation

    Directory of Open Access Journals (Sweden)

    Dominga Lapi


    Full Text Available The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals. During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart and brain, and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is requested within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing.The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min by jaw extension in rats produces interesting effects both at systemic and cerebral level, reducing the arterial blood pressure and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activated the nitric oxide release by vascular endothelial. Therefore the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension, because produced opposite effects compared to those elicited by the diving reflex as it induces hypotension and modulation of cerebral arteriolar tone.

  16. Linear time delay methods and stability analyses of the human spine. Effects of neuromuscular reflex response. (United States)

    Franklin, Timothy C; Granata, Kevin P; Madigan, Michael L; Hendricks, Scott L


    Linear stability methods were applied to a biomechanical model of the human musculoskeletal spine to investigate effects of reflex gain and reflex delay on stability. Equations of motion represented a dynamic 18 degrees-of-freedom rigid-body model with time-delayed reflexes. Optimal muscle activation levels were identified by minimizing metabolic power with the constraints of equilibrium and stability with zero reflex time delay. Muscle activation levels and associated muscle forces were used to find the delay margin, i.e., the maximum reflex delay for which the system was stable. Results demonstrated that stiffness due to antagonistic co-contraction necessary for stability declined with increased proportional reflex gain. Reflex delay limited the maximum acceptable proportional reflex gain, i.e., long reflex delay required smaller maximum reflex gain to avoid instability. As differential reflex gain increased, there was a small increase in acceptable reflex delay. However, differential reflex gain with values near intrinsic damping caused the delay margin to approach zero. Forward-dynamic simulations of the fully nonlinear time-delayed system verified the linear results. The linear methods accurately found the delay margin below which the nonlinear system was asymptotically stable. These methods may aid future investigations in the role of reflexes in musculoskeletal stability.

  17. Pelviureteral inhibitory reflex and ureteropelvic excitatory reflex: role of the two reflexes in regulation of urine flow from the renal pelvis to the ureter. (United States)

    Shafik, A


    The mechanism by which the ureteropelvic junction (UPJ) regulates the passage of urine from the renal pelvis to the ureter, and prevents urinary backflow from the the ureter to the renal pelvis, is not completely understood. The current communication studies this mechanism in 18 dogs. With the dogs under anesthesia, nephrostomy was done through which two catheters (one pressure and one balloon-tipped) were introduced into the UPJ and the renal pelvis, respectively. Renal pelvis distension with a balloon filled with 1 ml of saline effected a rise of renal pelvic pressure from a mean basal pressure of 4.8 +/- 1.2 cm H2O to 6.9 +/- 2.3 cm H2O (P pelvic balloon (P > 0.05). Renal pelvic distension with 2, 3, and 4 ml caused a significant rise of renal pelvic pressure to 8.4 +/- 2.7 (P elevation of ureteric and UPJ pressure which was not significantly different from that observed with distension with 0.5 ml (P > 0.05). In contrast, the UPJ showed no significant pressure change upon distension of the locally anesthetized renal pelvis or ureter, respectively. Likewise, the locally anesthetized UPJ exhibited no significant pressure response to renal pelvic or ureteric distension. The study demonstrates that urine might have to accumulate in the renal pelvis up to a certain volume and pressure so as to effect UPJ opening, which occurs at its maximum irrespective of the distending volume. UPJ opening upon renal pelvic distension postulates a reflex relationship which we call "pelviureteral inhibitory reflex." This reflex is believed to regulate the passage of urine from the renal pelvis to the ureter. Ureteric distension closes the UPJ; we call this reflex action the "ureteropelvic excitatory reflex" as it seems to prevent reflux of urine through the UPJ and thus protects the kidney. The concept that the UPJ acts as a physiologic sphincter is put forward.

  18. Posture modulates the sensitivity of the H-reflex. (United States)

    Cecen, Serpil; Niazi, Imran Khan; Nedergaard, Rasmus Wiberg; Cade, Alice; Allen, Kathryn; Holt, Kelly; Haavik, Heidi; Türker, Kemal S


    The effect of body posture on the human soleus H-reflex via electrical stimulation of the tibial nerve at the popliteal fossa was studied. All parameters that may influence the reflex were controlled stringently. H-reflexes were elicited in three different body postures while keeping the level of background muscle activation to a minimum. The H-reflex curve relative to the M-wave curve did not change significantly in any of the body postures. However, the maximal H-reflex amplitude significantly increased in the prone position compared with the sitting (p = 0.02) and standing positions (p = 0.01). The background level of electrical activity of the soleus muscle did not significantly change during varying body postures. Together, these findings indicate that the effectiveness of the spindle primary afferent synapse on the soleus motor neuron pool changes significantly in prone position as compared to sitting and standing positions. Given that we have controlled the confounding factors excluding the head position relative to the gravity and the receptors that may be differentially activated at varying body postures such as the proprioceptors, it is concluded that the tonic activity from these receptors may presynaptically interfere with the effectiveness of the spindle primary afferent synapses on the soleus motor neurons.

  19. Contraction induced h reflexes in the diagnosis of cervical radiculopathy. (United States)

    Bodofsky, Elliot B; Campellone, Joseph V; Cohen, Stephen J; Caten, Holly N; Schindelheim, Adam M


    To determine whether Contraction Induced H Reflexes (CIHR) can accurately detect cervical radiculopathy. Comparison of CIHR results with Needle Electromyography at academic outpatient Electromyography/Nerve Conduction laboratories. Participants were all patients over 18 with a needle electromyography diagnosis of cervical radiculopathy. Patients were tested for CIHR in at least two upper extremity muscles in electromyographically proven myotomes bilaterally. Patients were requested to perform a moderate contraction while stimulus was applied proximally (elbow or Erb's point). Outcome measures included H Reflex onset latency and side-to-side latency differences. These were compared against previously established normal values. Overall, 10 of 15 patients who met criteria for cervical radiculopathy showed CIHR abnormalities (sensitivity = 67%; 95% confidence interval, 43-91). Counting each side and level separately, CIHR identified 16/27 radiculopathies (sensitivity = 59.2%; 95% confidence interval, 40.6-77.8). Contraction Induced H Reflexes identified 1 possible radiculopathy not seen on electromyography (specificity = 98%; 95% confidence interval, 95-100). Contraction induced H Reflexes have a sensitivity and specificity for cervical radiculopathy similar to the resting Gastroc-Soleus H Reflex.

  20. Trigeminocardiac Reflex: A Reappraisal with Relevance to Maxillofacial Surgery. (United States)

    Bhargava, Darpan; Thomas, Shaji; Chakravorty, Nupur; Dutt, Ashutosh


    The purpose of this paper was to undertake a review of literature on trigeminocardiac reflex in oral and maxillofacial online data-base and discuss the pathophysiology, risk factor assessment, presentation of the reflex, prevention, management with emphasis on the role of the attending anaesthetist and the maxillofacial surgeon. The available literature relevant to oral and maxillofacial surgery in online data-base of the United States National Library of Medicine: Pubmed ( was searched. The inclusion criterion was to review published clinical papers, abstracts and evidence based reviews on trigeminocardiac reflex relevant to oral and maxillofacial surgery. Sixty-five articles were found with the search term "trigeminocardiac reflex" in the literature searched. Eighteen articles met the inclusion criteria for this study. The relevant data was extracted, tabulated and reviewed to draw evidence based conclusions for the management of trigeminocardiac reflex. Conclusions were drawn and discussed based on the reviewed maxillofacial literature with emphasis on the anaesthetist's and the surgeon's role in the management of this detrimental event in maxillofacial surgical practice.

  1. Intranasal Midazolam May Prevent Gagging Reflex: a Case Report

    Directory of Open Access Journals (Sweden)

    Meral Arslan Malkoc


    Full Text Available Background: Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old with exaggerated gag reflex referred to Faculty of Dentistry of Selçuk University.Methods: During obtaining records, taking impression procedure was elicited the patients’ hypersensitive gagging reflex. Therefore, it was decided to administer intranasal midazolam to facilitate the taking of accurate dental impressions. After given verbal information about the procedure, 2.5 mg intranasal midazolam (Demizolam, Dem Medikal, Istanbul were applied incrementally in both nostrils.Results: Five minutes later; patients had no gagging reflex and allowed the clinician to take satisfying impressions. No serious adverse effects were observed and the patients remained cooperative during the entire procedure which was completed to the full satisfaction of all involved. The short absorption time and the fast relief process of anaesthetics transferred to the systemic circulatory system are important advantages of nasal application.Conclusions: Intranasal midazolam may be very useful for the treatment of gag reflex probably effecting on the depression of upper airway reflex sensitivity.

  2. Intranasal midazolam may prevent gagging reflex: a case report. (United States)

    Malkoc, Meral Arslan; Demir, Necla; Ileri, Zehra; Erdur, Aybuke; Apiliogullari, Seza


    Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old) with exaggerated gag reflex referred to Faculty of Dentistry of Selçuk University. During obtaining records, taking impression procedure was elicited the patients' hypersensitive gagging reflex. Therefore, it was decided to administer intranasal midazolam to facilitate the taking of accurate dental impressions. After given verbal information about the procedure, 2.5 mg intranasal midazolam (Demizolam, Dem Medikal, Istanbul) were applied incrementally in both nostrils. Five minutes later; patients had no gagging reflex and allowed the clinician to take satisfying impressions. No serious adverse effects were observed and the patients remained cooperative during the entire procedure which was completed to the full satisfaction of all involved. The short absorption time and the fast relief process of anaesthetics transferred to the systemic circulatory system are important advantages of nasal application. Intranasal midazolam may be very useful for the treatment of gag reflex probably effecting on the depression of upper airway reflex sensitivity.

  3. Time and direction preparation of the long latency stretch reflex. (United States)

    Nikaido, Yasutaka; Hatanaka, Ryota; Jono, Yasutomo; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi


    This study investigated time and direction preparation of motor response to force load while intending to maintain the finger at the initial neutral position. Force load extending or flexing the index finger was given while healthy humans intended to maintain the index finger at the initial neutral position. Electromyographic activity was recorded from the first dorsal interosseous muscle. A precue with or without advanced information regarding the direction of the forthcoming force load was given 1000ms before force load. Trials without the precue were inserted between the precued trials. A long latency stretch reflex was elicited by force load regardless of its direction, indicating that the long latency stretch reflex is elicited not only by muscle stretch afferents, but also by direction-insensitive sensations. Time preparation of motor response to either direction of force load enhanced the long latency stretch reflex, indicating that time preparation is not mediated by afferent discharge of muscle stretch. Direction preparation enhanced the long latency stretch reflex and increased corticospinal excitability 0-20ms after force load when force load was given in the direction stretching the muscle. These enhancements must be induced by preset of the afferent pathway mediating segmental stretch reflex. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. [MRI symptomology in reflex sympathetic dystrophy of the foot]. (United States)

    Darbois, H; Boyer, B; Dubayle, P; Lechevalier, D; David, H; Aït-Ameur, A


    To describe the MRI findings of reflex sympathetic dystrophy of the foot and ankle. Retrospective study of 50 patients with reflex sympathetic dystrophy of the foot (5 with the cold form, and 45 with the warm form) diagnosed based on clinical and scintigraphic findings. All patients underwent MR imaging. The MRI findings were correlated with the clinical and scintigraphic findings. Patients with the cold form of reflex sympathetic dystrophy had no abnormality of signal at MR imaging. All patients with the warm from of reflex sympathetic dystrophy showed periarticular marrow edema at MR, typically involving more than one bone (mean of 4). Other findings were inconstant: soft tissue edema, joint effusion, and rarely, subchondral band of low T1W signal intensity of unclear etiology. MR imaging, including fat-suppressed T2W or STIR images and noncontrast T1W images, is helpful in patients with the warm or acute form of reflex sympathetic dystrophy of the foot. In patients with the cold form, MR imaging is helpful to exclude another underlying etiology for the symptoms and identify patients with the warm form of the process.

  5. Faroese long-distance reflexives face off against Icelandic long-distance reflexives

    Directory of Open Access Journals (Sweden)

    Tania E. Strahan


    Full Text Available Long-distance reflexives (LDRs in Faroese are often compared to those in Icelandic, and are even considered to have the same distribution (Thráinsson et al., 2004. In this paper I evaluate the extent to which this is true. The results from recent fieldwork show that there are clear differences between the LDR in the two closely related languages, in particular that Faroese speakers often reject LDR sentences that contain a non-third person, and that Faroese LDR is often completely acceptable out of a non-complement clause. In addition, initial findings suggest that there may be dialectal variation with respect to at least these two aspects of LDR in Faroese.

  6. Reflex anuria: a rare cause of acute kidney injury

    Directory of Open Access Journals (Sweden)

    Samuel Adediran


    Full Text Available Background: Acute Kidney Injury results from pre renal, post renal or intrinsic renal causes. Reflex anuria is a very rare cause of renal impairment which happens due to irritation or trauma to one kidney or ureter, or severely painful stimuli to other nearby organs. Case Presentation: Here we present a case of acute kidney injury secondary to reflex anuria in a patient who underwent extensive gynecological surgery along with ureteral manipulation which recovered spontaneously. Conclusion: Reflex Anuria is a rare and often not considered as cause of acute kidney injury. This case illustrates that this should be kept as a differential in potential cause of acute kidney injury in patient undergoing urogenital or gynecological surgeries.

  7. Single Canonical Model of Reflexive Memory and Spatial Attention. (United States)

    Patel, Saumil S; Red, Stuart; Lin, Eric; Sereno, Anne B


    Many neurons in the dorsal and ventral visual stream have the property that after a brief visual stimulus presentation in their receptive field, the spiking activity in these neurons persists above their baseline levels for several seconds. This maintained activity is not always correlated with the monkey's task and its origin is unknown. We have previously proposed a simple neural network model, based on shape selective neurons in monkey lateral intraparietal cortex, which predicts the valence and time course of reflexive (bottom-up) spatial attention. In the same simple model, we demonstrate here that passive maintained activity or short-term memory of specific visual events can result without need for an external or top-down modulatory signal. Mutual inhibition and neuronal adaptation play distinct roles in reflexive attention and memory. This modest 4-cell model provides the first simple and unified physiologically plausible mechanism of reflexive spatial attention and passive short-term memory processes.

  8. Changes of Reflex, Non-reflex and Torque Generation Properties of Spastic Ankle Plantar Flexors Induced by Intelligent Stretching. (United States)

    Chung, S; Bai, Z; Rymer, W Z; Zhang, L Q


    Spasticity, contracture, and muscle weakness are major sources of disability in stroke. Changes of torque-generating capacity as well as reflex and non-reflex properties of ankle plantar flexors induced by strenuous stretching in chronic hemiplegia were investigated. Twelve subjects with a unilateral stroke and 10 healthy controls underwent 30 minutes of strenuous intelligent stretching treatment. Reflex and non-reflex components of spastic hypertonia and force-generating capacity of ankle plantar flexors were investigated. Dorsiflexion (DF) range of motion (ROM) was increased (p=0.002) and passive stiffness and passive resistant torque of the spastic muscles were decreased (p=0.004 and 0.007, respectively), while reflex hyper-excitability diminished slightly but with no statistical significance. The maximal voluntary contraction (MVC) torque of the spastic ankle plantar flexors was increased after the forceful stretching treatment (p=0.041). In contrast, the stretching treatment of the healthy plantar flexors did not change any of the variables measured before and after stretching. The stroke subjects who gained more DF ROM or larger decrement of stiffness achieved greater increment of the peak torque generation after the stretching (r=0.597 with p=0.040 and r=-0.746 with p=0.005, respectively). These results suggest that the strenuous dynamic stretching could improve the force-generating capacity of spastic muscles as well as reduce the passive stiffness and increase ROM.

  9. Spinal reflex excitability changes after lumbar spine passive flexion mobilization. (United States)

    Bulbulian, Ronald; Burke, Jeanmarie; Dishman, J Donald


    Flexion distraction has gained increased credibility as a therapeutic modality for treatment of low back pain. Although important work in the area has elucidated the intradiskal pressure profiles during flexion distraction, the accompanying neural responses have yet to be described. The purpose of this pilot study was to assess neural reflex responses to motion with 3 degrees of freedom applied to the lumbar spine and to evaluate H-reflex responses of the soleus. Subjects (n = 12) were measured for H-maximum reflexes determined from stimulus response recruitment curves measured in neutral prone position. The mean of 10 evoked H-waves (at H-maximum stimulus intensity) were measured in neutral position, flexion, left and right lateral flexion, and axial rotation of the trunk on an adjusting table. H-reflexes were expressed as a percentage of maximal M-wave for the criterion measure. Spinal range of motion was quantified by digitization. The data showed variation in some movement ranges, notwithstanding identical table positioning for all subjects. Mean H-reflex amplitude was decreased (15.2 +/- 5.8 mV to 13.8 +/- 5.8 mV), and the H/M ratio was also decreased in flexion compared with neutral (55.0% +/- 19.1% to 50.3% +/- 19.4%; P <.05). Trunk flexion is accompanied by inhibition of the motor neuron pool. Slight perturbations in numerous afferent receptors are known to significantly alter the H-reflex. The absence of measurable changes in lateral flexion and trunk rotation may indicate that both slow- and fast-adapting receptors could be involved in lumbar motion. These preliminary findings suggest the need for further dynamic motion studies of the flexion distraction neurophysiologic condition.

  10. Automated data reduction workflows for astronomy. The ESO Reflex environment (United States)

    Freudling, W.; Romaniello, M.; Bramich, D. M.; Ballester, P.; Forchi, V.; García-Dabló, C. E.; Moehler, S.; Neeser, M. J.


    Context. Data from complex modern astronomical instruments often consist of a large number of different science and calibration files, and their reduction requires a variety of software tools. The execution chain of the tools represents a complex workflow that needs to be tuned and supervised, often by individual researchers that are not necessarily experts for any specific instrument. Aims: The efficiency of data reduction can be improved by using automatic workflows to organise data and execute a sequence of data reduction steps. To realize such efficiency gains, we designed a system that allows intuitive representation, execution and modification of the data reduction workflow, and has facilities for inspection and interaction with the data. Methods: The European Southern Observatory (ESO) has developed Reflex, an environment to automate data reduction workflows. Reflex is implemented as a package of customized components for the Kepler workflow engine. Kepler provides the graphical user interface to create an executable flowchart-like representation of the data reduction process. Key features of Reflex are a rule-based data organiser, infrastructure to re-use results, thorough book-keeping, data progeny tracking, interactive user interfaces, and a novel concept to exploit information created during data organisation for the workflow execution. Results: Automated workflows can greatly increase the efficiency of astronomical data reduction. In Reflex, workflows can be run non-interactively as a first step. Subsequent optimization can then be carried out while transparently re-using all unchanged intermediate products. We found that such workflows enable the reduction of complex data by non-expert users and minimizes mistakes due to book-keeping errors. Conclusions: Reflex includes novel concepts to increase the efficiency of astronomical data processing. While Reflex is a specific implementation of astronomical scientific workflows within the Kepler workflow

  11. Neurophysiology and Clinical Implications of the Laryngeal Adductor Reflex. (United States)

    Domer, Amanda S; Kuhn, Maggie A; Belafsky, Peter C


    The laryngeal adductor reflex (LAR) is an involuntary protective response to stimuli in the larynx. The superior laryngeal nerve (SLN) acts as the afferent limb and the recurrent laryngeal nerve (RLN) as the efferent limb of this reflex, which is modulated by the central nervous system. Perhaps the most clinically significant application of the LAR is its use in laryngopharyngeal (LP) sensory discrimination testing. Importantly, aberrations in the LAR may predict dysphagia or portend clinical phenotypes of chronic cough, vocal cord dysfunction or pediatric apneas. LP sensation is a potential target for interventions addressing the aforementioned conditions though currently remains an area of active investigation.

  12. [Reflex sympathetic dystrophy: description of a case with skin lesions]. (United States)

    Vergara, Aránzazu; Isarría, María J; Prado Sánchez-Caminero, María; Guerra, Aurora


    Reflex sympathetic dystrophy or algodystrophy is a poorly defined syndrome in which the patient develops pain disproportionate to the cause. It is included among the complex regional pain syndromes. The symptoms are triggered by some type of trauma, at times trivial, and consist of burning pain, edema, changes in skin color, alterations in vascularization, temperature changes, hyperhidrosis and skin disorders, which primarily consist of atrophic changes. Other less frequent cutaneous manifestations have been described in patients with this syndrome. These include papules, blisters, inflammatory lesions and reticulated hyperpigmentation. We discuss the case of a patient with reflex sympathetic dystrophy who presented with superficial ulcers on the affected limb, which mimicked dermatitis artefacta.

  13. Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury


    Onushko, Tanya; Hyngstrom, Allison; Schmit, Brian D.


    Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conv...

  14. Trait dominance promotes reflexive staring at masked angry body postures

    NARCIS (Netherlands)

    Hortensius, R.; van Honk, J.; De Gelder, B.; Terburg, D.


    It has been shown that dominant individuals sustain eye-contact when non-consciously confronted with angry faces, suggesting reflexive mechanisms underlying dominance behaviors. However, dominance and submission can be conveyed and provoked by means of not only facial but also bodily features. So

  15. Reflexive Processes in the Musician Performer's Professional Activities (United States)

    Nussipzhanova, Bibigul N.; Dzherdimalieva, Gulnar M.; Stamgaziev, Ramazan U.


    The article attempts to identify the gradual development of the category of reflection as one of the driving factors of self-actualization, to reveal meaningful face value and basic directions of its multi-dimensional interpretation. The profiling property of a performer's reflexive action acts as a basic psychological foundation in the…

  16. Approaching Reflexivity through Reflection: Issues for Critical Management Education (United States)

    Hibbert, Paul


    This conceptual article seeks to develop insights for teaching reflexivity in undergraduate management classes through developing processes of critical reflection. Theoretical inferences to support this aim are developed and organized in relation to four principles. They are as follows: first, preparing and making space for reflection in the…

  17. Knowledge generation and utilisation in occupational therapy: towards epistemic reflexivity. (United States)

    Kinsella, Elizabeth Anne; Whiteford, Gail Elizabeth


    The purpose of this article is to consider the ways in which theory generation, and hence knowledge generation, in occupational therapy is a complex social process, and therefore carries (often hidden) responsibilities for those who are part of our epistemic community. An epistemic community is a knowledge-producing community, who apply their standards of credibility, and epistemic values, to theory choice. In occupational therapy this community is comprised of a worldwide group of scholars and practitioners. We propose that epistemic reflexivity can be used to critique and contribute to our disciplinary knowledge and to critically consider 'who' makes epistemological choices in our profession, and the consequent implications for the theories we adopt. The purpose of this article is to make these relations explicit so that scholars and therapists can become increasingly conscious and empowered with respect to their contributions to occupational therapy's epistemic community. To demonstrate an application of epistemic reflexivity, we critically consider a theoretical construction that has been widely adopted by the international occupational therapy community: evidence-based practice. As authors, we engage in epistemic reflexivity to critically consider the challenge posed by evidence-based practice. We propose a conception of practice knowledge that is informed by evidence yet based on a conception of wise practice. Our intention is to stimulate discussion and debate in occupational therapy's epistemic community, a number of approaches for fostering epistemic reflexivity in occupational therapy are suggested.

  18. PhD Students, Interculturality, Reflexivity, Community and Internationalisation (United States)

    Holliday, Adrian


    Interviews with a small group of doctoral students at a British university indicate that the students feel that the programme provides an environment within which they develop interculturality through reflexive engagement with the PhD community and in some cases with the participants in their research. Significant here is that they are…

  19. Brainstem mechanisms underlying the cough reflex and its regulation. (United States)

    Mutolo, Donatella


    Cough is a very important airway protective reflex. Cough-related inputs are conveyed to the caudal nucleus tractus solitarii (cNTS) that projects to the brainstem respiratory network. The latter is reconfigured to generate the cough motor pattern. A high degree of modulation is exerted on second-order neurons and the brainstem respiratory network by sensory inputs and higher brain areas. Two medullary structures proved to have key functions in cough production and to be strategic sites of action for centrally active drugs: the cNTS and the caudal ventral respiratory group (cVRG). Drugs microinjected into these medullary structures caused downregulation or upregulation of the cough reflex. The results suggest that inhibition and disinhibition are prominent regulatory mechanisms of this reflex and that both the cNTS and the cVRG are essential in the generation of the entire cough motor pattern. Studies on the basic neural mechanisms subserving the cough reflex may provide hints for novel therapeutic approaches. Different proposals for further investigations are advanced. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Reconceptualising Learning as a Form of Relational Reflexivity (United States)

    Dyke, Martin


    The paper makes a connection between transmission modes and constructivism in sociology and education, respectively. There are parallels between Archer's criticism of upward and downward conflation in social theory, and approaches to learning in education. In her 2012 book, Archer seeks to reconceptualise socialisation as relational reflexivity.…

  1. Team performance in the Italian NHS: the role of reflexivity. (United States)

    Urbini, Flavio; Callea, Antonino; Chirumbolo, Antonio; Talamo, Alessandra; Ingusci, Emanuela; Ciavolino, Enrico


    Purpose The purpose of this paper is twofold: first, to investigate the goodness of the input-process-output (IPO) model in order to evaluate work team performance within the Italian National Health Care System (NHS); and second, to test the mediating role of reflexivity as an overarching process factor between input and output. Design/methodology/approach The Italian version of the Aston Team Performance Inventory was administered to 351 employees working in teams in the Italian NHS. Mediation analyses with latent variables were performed via structural equation modeling (SEM); the significance of total, direct, and indirect effect was tested via bootstrapping. Findings Underpinned by the IPO framework, the results of SEM supported mediational hypotheses. First, the application of the IPO model in the Italian NHS showed adequate fit indices, showing that the process mediates the relationship between input and output factors. Second, reflexivity mediated the relationship between input and output, influencing some aspects of team performance. Practical implications The results provide useful information for HRM policies improving process dimensions of the IPO model via the mediating role of reflexivity as a key role in team performance. Originality/value This study is one of a limited number of studies that applied the IPO model in the Italian NHS. Moreover, no study has yet examined the role of reflexivity as a mediator between input and output factors in the IPO model.

  2. Soleus H-reflex excitability during pedaling post-stroke

    DEFF Research Database (Denmark)

    Schindler-Ivens, Sheila; Brown, David A.; Lewis, Gwyn N.


    A major contributor to impaired locomotion post-stroke is abnormal phasing of paretic muscle activity, but the mechanisms remain unclear. Previous studies have shown that, in the paretic limb of people post-stroke, Group Ia reflexes are abnormally elevated and fail to decrease in amplitude during...

  3. Enhancing the Reflexivity of System Innovation Projects With System Analyses

    NARCIS (Netherlands)

    Mierlo, van B.C.; Arkesteijn, M.C.M.; Leeuwis, C.


    Networks aiming for fundamental changes bring together a variety of actors who are part and parcel of a problematic context. These system innovation projects need to be accompanied by a monitoring and evaluation approach that supports and maintains reflexivity to be able to deal with uncertainties

  4. Power from Switching across Netdoms through Reflexive and Indexical Language.

    Directory of Open Access Journals (Sweden)

    Fontdevila, Jorge


    Full Text Available In differentiated societies with far-reaching yet fragmented social networks, the ability to manage pervasive ambiguity is crucial to navigate domination orders. In this paper we contend that identities, to enhance their control through switchings across networks and domains (netdoms, manage growing ambiguity via language’s reflexive and indexical features. We elaborate on several features—metapragmatics, heteroglossia, and poetics—and assert that they are seldom innocent performances to build consensus in the reproduction of social orders. On the contrary, language is inherently implicated in relations of domination. We then argue that metapragmatic control of stories acquired in countless netdom switchings leads to strong footings that secure resources and opportunity; that rhetorics that include rich heteroglossic voicing via structural holes generate stories that can be reflexively transposed to other institutional arenas; and that poetic control of speech styles may transform identities into power-law constellations with robust footing that decouple into prisms to preserve quality. Our goal is to twofold: First, to show that the reflexivity and indexicality of language emerges from myriad switchings across netdoms; and second, to demonstrate that reflexive and indexical language is critical to identities’ struggles for control—of footing and domination—via their switchings across rapidly polymerizing netdoms.

  5. Reflexive modules with finite Gorenstein dimension with respect to a ...

    Indian Academy of Sciences (India)

    Proc. Indian Acad. Sci. (Math. Sci.) Vol. 125, No. 1, February 2015, pp. 21–28. c Indian Academy of Sciences. Reflexive modules with finite Gorenstein dimension with respect to a semidualizing module. ELHAM TAVASOLI1,∗, MARYAM SALIMI1 and SIAMAK YASSEMI2,3. 1Department of Mathematics, East Tehran Branch, ...

  6. Obligatory Reflexivity in a Minimalist Grammar of Afrikaans ...

    African Journals Online (AJOL)

    This paper deals with the phenomenon of obligatory reflexivity in Afrikaans. Adopting the general framework of Minimalist Syntax, an attempt is made to develop a novel analysis of this phenomenon that can provide a conceptually adequate account for the facts, and that is amenable to extension beyond Afrikaans.

  7. Reflexive competence and the construction of meaning: the ...

    African Journals Online (AJOL)

    Globalised systems often reflect an array of ambivalent values. Persons participating in such systems need a strong sense of personal identity and the ability to have a deeper sense of meaning in their lives. Higher theological education that has a strong emphasis on reflexive competence can help learners to constructing ...

  8. Critical reflexivity in client-centred therapeutic relationships. (United States)

    McCorquodale, Lisa; Kinsella, Elizabeth Anne


    This paper explores how a particular form of reflection--critical reflexivity--can support clinicians in developing a more nuanced understanding of therapeutic relationships, and work to advance the goal of client-centred practice. A critical autobiographical narrative was written, and critical reflexivity adopted, as methods to critically examine the therapeutic relationship. Critically reflexive stories have the potential to advance client-centred therapeutic relationships by inspiring the (re-)consideration of practices, and by interrogating interpretive systems. Understandings and practices that potentially limit the extent to which therapeutic relationships are client centred include (i) Dichotomous thinking, (ii) Objectification, (iii) The economic imperative, and (iv) Knowledge generation. The critical autobiographical account points to ways in which critical reflexivity on the therapeutic relationship has the potential to foster critical questioning, interrogate interpretive systems, attune to subjectivities, contribute to practice-based knowledge, resist violation, foster compassionate practice, and develop new understandings of relevance to client-centred practice. This critical examination of the therapeutic relationship supports occupational therapists in more fully realizing the profession's core value of client-centred practice.

  9. Axillary Brachial Plexus Blockade for the Reflex Sympathetic Dystrophy Syndrome. (United States)

    Ribbers, G. M.; Geurts, A. C. H.; Rijken, R. A. J.; Kerkkamp, H. E. M.


    Reflex sympathetic dystrophy syndrome (RSD) is a neurogenic pain syndrome characterized by pain, vasomotor and dystrophic changes, and often motor impairments. This study evaluated the effectiveness of brachial plexus blockade with local anaesthetic drugs as a treatment for this condition. Three patients responded well; three did not. (DB)

  10. Juxta-articular erosions in reflex sympathetic dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, H.J.; Virtama, P.

    Thirty-one patients with documented reflex sympathetic dystrophy syndrome (RSDS) were reviewed for their radiographic changes. Juxta-articular and metaphyseal bone loss was found in the majority of the patients. Juxta-articular bone loss closely resembling erosions seen in rheumatoid arthritis was found in all the patients. The significance of these findings is discussed.

  11. Reflex sympathetic dystrophy/complex regional pain syndrome. (United States)

    Gann, Charlotte


    Occupational health nurses are usually the first to assess workers with reflex sympathetic dystrophy/complex regional pain syndrome. Therefore, they must be aware of the signs and symptoms, implications for lost time, and higher incidence of disability related to this disorder.

  12. Reflex sympathetic dystrophy syndrome due to arteriovenous fistula. (United States)

    Unek, Ilkay Tugba; Birlik, Merih; Cavdar, Caner; Ersoy, Rifki; Onen, Fatos; Celik, Ali; Camsari, Taner


    A patient with end-stage renal disease presented with reflex sympathetic dystrophy syndrome (RSDS) on her left hand 1 month after arteriovenous fistula (AVF) surgery. Magnetic resonance angiography revealed steal syndrome at the AVF level. Bone scintigraphy revealed early-stage RSDS. We considered that arterial insufficiency because of steal phenomenon following AVF surgery and underlying occlusive arterial disease triggered RSDS development.

  13. Complex regional pain syndrome/reflex sympathetic dystrophy. (United States)

    Jakubowicz, Brian; Aner, Musa


    Questions from patients about analgesic pharmacotherapy and responses from the authors are presented to help educate patients and make them more effective self-advocates. The topics addressed in this issue are the signs, symptoms, and diagnosis of complex regional pain syndrome/reflex sympathetic dystrophy.

  14. Reflexively exploring knowledge and power in collaborative research

    DEFF Research Database (Denmark)

    Olesen, Birgitte Ravn; Pedersen, Chistina Hee; Frølunde, Lisbeth

    The proposed workshop will take its starting point in the challenges which collaborative research practices share. The aim of the workshop is to work with, and further develop, a range of critical, reflexive strategies for understanding, analysing and dealing with those challenges. The workshop...

  15. Reconceptualizing reflexivity and dissonance in professional and personal domains. (United States)

    Brooks, Ann


    Debates around 'reflexivity' and the construction of the gendered self within late modernity have occupied the attention of both 'reflexive modernization' theorists (Beck, Giddens and Lash 1994; Beck and Beck-Gernsheim 1996; Giddens 1991, 1992) as well as gender and feminist theorists. While theorists such as Beck and Giddens have been preoccupied with establishing the connection between reflexivity and the construction of the 'non-gendered' self, gender and feminist theorists have sought to amplify the debate by exploring the intersecting nexus of contemporary theorizing, more fully within this context. This paper explores the theoretical underpinnings of these debates and their application to specific professional and personal domains. I consider three case studies to assess these issues as outlined in my own work, Brooks 2006, and in the work of Wajcman and Martin 2002, and McDowell 1997, which draw on empirical research and explore changes to gender identity within professional and personal domains. I conclude that there is little evidence in the research presented here of any systematic reconfiguring of gender identities leading to a detraditionalization of gender as suggested by the 'reflexive modernization' theorists.

  16. Review article: Autonomous neural inflammatory reflex and control of

    African Journals Online (AJOL)

    ... and neural autonomic pathway through vagus nerve monitor inflammatory status and coordinate appropriate host defences. Immunomodulatory stimulation of vagus nerve, acetylcholinesterase inhibitory mechanism and 7 nAChR receptor expressed on immune cells plays a role on autonomous neural inflammatory reflex.

  17. Neural reflex pathways in intestinal inflammation: hypotheses to viable therapy

    NARCIS (Netherlands)

    Willemze, Rose A.; Luyer, Misha D.; Buurman, Wim A.; de Jonge, Wouter J.


    Studies in neuroscience and immunology have clarified much of the anatomical and cellular basis for bidirectional interactions between the nervous and immune systems. As with other organs, intestinal immune responses and the development of immunity seems to be modulated by neural reflexes.


    Directory of Open Access Journals (Sweden)

    Maryna Mavrina


    Full Text Available Development of theoretical approaches of demand management is conducted from the moment of awareness of the importance of this concept. Many models of individual consumers were developed. However, to predict the reaction of consumers to the commercial policy of the enterprise, exact methods do not exist yet because the available ones are mostly empirical in nature. Models of behaviour often do not provide the expected result because they use an erroneous approach to the analysis of the mechanism of demand formation. The subject of the research is the theoretical and methodological basis, methods of assessment, and reflexive management of consumer demand of commercial enterprises. The purpose of the paper is developing a concept of reflexive management of consumer demand. To achieve the research goal, the following tasks are set and solved: to substantiate the theoretical and methodological foundations of reflexive consumer management, to analyse existing approaches to the modelling of consumer behaviour; to improve the model of consumer behaviour; to develop a concept of reflexive management of consumer behaviour. Methodology. In the paper, we use such methods and approaches to research as: reflexive approach (phenomenological method, behavioural economic theory, marketing approach, abstract-logical analysis, analysis of theoretical approaches to the modelling of consumer behaviour. Results. Modern approaches to modelling of consumer behaviour are mostly empirical in nature and have shortcomings of general models. In them, there is no description of specific situations of the purchase of goods. They cannot be quantified. Therefore, they cannot be practical models. But they have a weighty advantage in a comprehensive look at motivated purchases, what makes it possible to evaluate the relevance of individual variables and to understand the fundamental processes of consumer behaviour. It makes possible to identify the variables necessary for the

  19. Study of nociceptive flexion reflex in healthy subjects and patients with chronic neuropathic pain syndrome. (United States)

    Gordeev, S A; Turbina, L G; Zus'man, A A; Posokhov, S I


    Nociceptive flexion reflex was measured in healthy subjects and patients with chronic neuropathic pain (diabetic distal symmetric sensorimotor polyneuropathy). The study of nociceptive flexion reflex revealed reduction of subjective pain threshold and reflex threshold in patients compared with healthy persons reflecting deficit of descending antinociceptive influences in the CNS.

  20. Introducing Reflexivity to Evaluation Practice: An In-Depth Case Study (United States)

    van Draanen, Jenna


    There is currently a paucity of literature in the field of evaluation regarding the practice of reflection and reflexivity and a lack of available tools to guide this practice--yet using a reflexive model can enhance evaluation practice. This paper focuses on the methods and results of a reflexive inquiry that was conducted during a participatory…

  1. Evaluation of relationship between feeding reflexes and articulation in spastic cerebral palsy

    Directory of Open Access Journals (Sweden)

    M.R. Hadian


    Full Text Available Background: Cerebral palsy is the term used to describe a movement disorder though to be the result of nonprogressive brain damage. Due to damage to CNS, it is associated with articulation disorder and abnormal feeding reflex. Lack of oral function control and coordination following feeding reflex disorders. Articulation disorders are seen in most of the cerebral palsied patients.This research aimed to determine the relationship between feeding reflexes and articulation in cerebral palsy (spasticchildren. Methods: This study was cross sectionally carried out on 52 children with cerebral palsy, 5 to 10 yrs old, in rehabilitation centers and private clinics. The information related to feeding reflexes was collected through direct observation of patient and evaluation of sound articulation through phonetic information test. Results: Statistical analysis carried out by SPSS and chi-square and fisher exact tests. Abnomal chewing and tongue reflex are more prevalent than other feeding reflexes.The relationship between lip reflex and articulation of p/m/r/y/f/č and chewing reflex with articulation of/z/š/ is meaningful. The relationship between biting reflex with articulation of /z/j/l/š/ is meaningful. The relationship between tongue reflex and rooting reflex with articulation of sound is not meaningful. Conclusion: With regard to the result of this research, it can be suggested that in children with cerebral palsy following feeding reflex disorders, abnormal posture during speech occurs that could have effect on articulation.

  2. The tibialis anterior reflex in healthy subjects and in L5 radicular compression

    NARCIS (Netherlands)

    Stam, J.


    Phasic stretch reflexes were evoked in the tibialis anterior (TA) muscle, by tapping the dorsal side of the foot with a hand-held reflex hammer. The responses were recorded by means of surface electrodes. The TA reflex was examined in 70 healthy subjects and in 18 patients with L5 radicular

  3. Isometric and Dynamic Control of Neck Muscles : Reflexive contributions and muscle synergies

    NARCIS (Netherlands)

    De Bruijn, E.


    It is well established that the central nervous system (CNS) stabilizes the head using reflexive feedback and cocontraction. The major reflexive pathways in the neck are through muscle spindles generating the cervicocollic reflex (CCR) and through the vestibular organ generating the vestibulocollic

  4. Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder (United States)

    Dichter, Gabriel S.; Benning, Stephen D.; Holtzclaw, Tia N.; Bodfish, James W.


    Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report…

  5. Reflexive intergroup bias in third-party punishment. (United States)

    Yudkin, Daniel A; Rothmund, Tobias; Twardawski, Mathias; Thalla, Natasha; Van Bavel, Jay J


    Humans show a rare tendency to punish norm-violators who have not harmed them directly-a behavior known as third-party punishment. Research has found that third-party punishment is subject to intergroup bias, whereby people punish members of the out-group more severely than the in-group. Although the prevalence of this behavior is well-documented, the psychological processes underlying it remain largely unexplored. Some work suggests that it stems from people's inherent predisposition to form alliances with in-group members and aggress against out-group members. This implies that people will show reflexive intergroup bias in third-party punishment, favoring in-group over out-group members especially when their capacity for deliberation is impaired. Here we test this hypothesis directly, examining whether intergroup bias in third-party punishment emerges from reflexive, as opposed to deliberative, components of moral cognition. In 3 experiments, utilizing a simulated economic game, we varied participants' group relationship to a transgressor, measured or manipulated the extent to which they relied on reflexive or deliberative judgment, and observed people's punishment decisions. Across group-membership manipulations (American football teams, nationalities, and baseball teams) and 2 assessments of reflexive judgment (response time and cognitive load), reflexive judgment heightened intergroup bias, suggesting that such bias in punishment is inherent to human moral cognition. We discuss the implications of these studies for theories of punishment, cooperation, social behavior, and legal practice. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  6. A reflexive neural network for dynamic biped walking control. (United States)

    Geng, Tao; Porr, Bernd; Wörgötter, Florentin


    Biped walking remains a difficult problem, and robot models can greatly facilitate our understanding of the underlying biomechanical principles as well as their neuronal control. The goal of this study is to specifically demonstrate that stable biped walking can be achieved by combining the physical properties of the walking robot with a small, reflex-based neuronal network governed mainly by local sensor signals. Building on earlier work (Taga, 1995; Cruse, Kindermann, Schumm, Dean, & Schmitz, 1998), this study shows that human-like gaits emerge without specific position or trajectory control and that the walker is able to compensate small disturbances through its own dynamical properties. The reflexive controller used here has the following characteristics, which are different from earlier approaches: (1) Control is mainly local. Hence, it uses only two signals (anterior extreme angle and ground contact), which operate at the interjoint level. All other signals operate only at single joints. (2) Neither position control nor trajectory tracking control is used. Instead, the approximate nature of the local reflexes on each joint allows the robot mechanics itself (e.g., its passive dynamics) to contribute substantially to the overall gait trajectory computation. (3) The motor control scheme used in the local reflexes of our robot is more straightforward and has more biological plausibility than that of other robots, because the outputs of the motor neurons in our reflexive controller are directly driving the motors of the joints rather than working as references for position or velocity control. As a consequence, the neural controller and the robot mechanics are closely coupled as a neuromechanical system, and this study emphasizes that dynamically stable biped walking gaits emerge from the coupling between neural computation and physical computation. This is demonstrated by different walking experiments using a real robot as well as by a Poincaré map analysis



    Chen, Yi; Wang, Yu; Chen, Lu; Sun, Chenyuo; English, Arthur W.; Wolpaw, Jonathan R.; Chen, Xiang Yang


    Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague-Dawley rats were implanted with EMG electro...

  8. O conceito de reflexão de Hegel como crítica aos conceitos de essência e de reflexão tradicionais

    Directory of Open Access Journals (Sweden)

    Christian Iber


    Full Text Available O presente artigo ilumina o específico do conceito de reflexão de Hegel em cinco momentos. Em um primeiro momento, delineia-se um esboço do conceito de reflexão na lógica da essência de Hegel. Em um segundo momento, o conceito de reflexão de Hegel é apresentado como estrutura lógica objetiva em contraste com a reflexão subjetiva da consciência e do entendimento, com a qual, ao mesmo tempo, o conceito de essência ontológica independente da reflexão é submetido a uma crítica. Do novo conceito de reflexão de Hegel resulta, em terceiro lugar, uma adaptação radical do círculo vicioso na teoria tradicional da reflexão da autoconsciência. Num quarto momento, lança-se um olhar sobre o conceito de reflexão anterior de Hegel como pensar do entendimento que separa, do qual o conceito de reflexão posterior se distingue. Por fim, apresenta-se, em quinto lugar, a lógica da reflexão de Hegel como crítica à fundação ontológica da reflexão em Schelling. O conceito de reflexão de Hegel se mostra, com isto, como crítica da metafísica ontológica tradicional e como fundação de uma metafísica da relacionalidade absoluta que supera a relatividade do pensar moderno do entendimento.

  9. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats. (United States)

    Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso


    Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

  10. Post-activation depression of soleus stretch reflexes in healthy and spastic humans

    DEFF Research Database (Denmark)

    Grey, Michael James; Klinge, Klaus; Crone, Clarissa


    delivered at different intervals. The magnitude of the stretch reflex and ankle torque response was assessed as a function of the time between perturbations. Soleus stretch reflexes were evoked with constant velocity (175 degrees /s) and amplitude (6 degrees ) plantar flexion perturbations. Soleus H......-reflexes were evoked by electrical stimulation of the tibial nerve in the popliteal fossa. The stretch reflex and H-reflex responses of 30 spastic participants (with multiple sclerosis or spinal cord injury) were compared with those of 15 healthy participants. In the healthy participants, the magnitude...


    Directory of Open Access Journals (Sweden)

    Vyatcheslav V Andrianov


    Full Text Available We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the neurotoxic analogues of serotonin, 5,6- or 5,7-dihydroxytryptamine (5,6/5,7-DHT were used. Injection of 5,6/5,7-DHT was found to disrupt defensive reflex conditioning. Within two weeks of neurotoxin application, the ability to learn had recovered. Daily injection of serotonin before a training session accelerated defensive reflex conditioning and daily injections of 5-HTP in snails with a deficiency of serotonin induced by 5,7-DHT restored the snail’s ability to learn. We discovered that injections of the neurotoxins 5,6/5,7-DHT as well as serotonin, caused a decrease in the resting and threshold potentials of the premotor interneurons LPa3 and RPa3.

  12. Explicating Positionality: A Journey of Dialogical and Reflexive Storytelling

    Directory of Open Access Journals (Sweden)

    Celina Carter MN


    Full Text Available Qualitative researchers must be aware of and explicit about their social background as well as political and ideological assumptions. To facilitate this awareness, we believe that researchers need to begin with their own story as they seek to understand the stories of others. Taking into account the vulnerable act of storytelling, it is salient to consider how to share personal narratives in an authentic way within academic settings. In this article, we share our process and reflections of engaging in reflexive and dialogical storytelling. The focus of the article is the re-storying of one researcher's experience as she and her research team explore her emotions and positionality prior to conducting research on First Nations men's narratives of identity. We integrate a series of methodological lessons concerning reflexivity throughout the re-storying.

  13. Startle and blink reflex in high functioning autism. (United States)

    Erturk, Ozdem; Korkmaz, Baris; Alev, Gulce; Demirbilek, Veysi; Kiziltan, Meral


    An important clinical feature of autism is the presence of atypical responses to sensory stimuli. In this study, we investigated if high functioning autistic patients had abnormalities in the blink reflex and the startle reaction to auditory or somatosensory stimuli. Fourteen patients aged between 7 and 16 years were included in the study. We found a longer latency of the blink reflex, an increased duration and amplitude of the auditory startle reaction and a lower presence rate of the somatosensorial startle reaction in autistic patients. To better define the sensorial characteristics of the disease could improve the therapeutic management of children with autism spectrum disorder. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Teacher education and the challenges of the reflexive practice

    Directory of Open Access Journals (Sweden)

    Maria Regina Peres


    Full Text Available This article approaches the importance of teacher practice and their initial and continuing education in the light of the challenges offered by the critical reflexive proposal. The aims of this study were to investigate the underlying assumptions regarding teachers’ current education and practice, to research and analyze the major difficulties found in the development of teaching practice, to comprehend and analyze the complexity inherent to the teacher’s performance in the initial years of elementary school. A bibliographic research and a qualitative research with elementary school teachers were therefore developed. The results indicate that although teachers believe the learning process to be continuous, they do not invest in this type of education. Furthermore it was found that teachers’ critical reflexive attitudes are blended with eproductivist attitudes.

  15. Becoming Bermuda grass: mapping and tracing rhizomes to practice reflexivity (United States)

    Murakami, Christopher D.; Siegel, Marcelle A.


    This narrative project used rhizomatic analysis and reflexivity to describe a layered process of responding to a student's identity of non-participation within an undergraduate science classroom. Mapping rhizomes represents an ongoing and experimental process in consciousness. Rhizomatic mapping in educational studies is too often left out of the products of academic pursuits. In this paper, we try to capture this process, and let the process capture us. This manuscript starts with a focus on just one student, but maps our reflexive terrain that helped us think in new ways about persistent problems in science learning. As we decided how to address this student's identity of non-participation, we learned about the intertwined stories of the researchers and the researched and the challenges of designing inclusive learning environments.

  16. Correlation of gastroesophageal reflex with aspiration pneumonia after surgery

    International Nuclear Information System (INIS)

    Hirashima, Tokuji; Hashimoto, Hajime; Noro, Toshio; Takahashi, Tadao; Hino, Yasunori; Kuroiwa, Kouzirou


    In order to elucidate the correlation of gastroesophageal reflex (GER) with aspiration pneumonia after surgery, 48 patients (mean, 75.6 years) with gastric cancer treated at the hospital from March, 1994 to December, 1994 were subjected to this prospective study. The pharyngeal stimulation test, nutritional assessment, radionuclide esophageal scintigraphy (34 cases) were performed before surgery and relationship between those results and aspiration pneumonia were studied. Aspiration pneumonia occurred in 3 cases, and all of them were in, significantly, poor nutritional status, compared with other. A significant increase in the frequency of GER was observed when a naso-gastric tube (NGT) was placed, but surprisingly, all the patients with aspiration pneumonia were 3 out of 4 patients who had continuous GER without NGT. It is noteworthy, continuous GER without NGT was significantly (p<0.001) affected postoperative aspiration pneumonia and impaired phalyngeal reflex was frequently correlated with development of aspiration pneumonia, when malnutritional status existed. (author)

  17. Review Essay: Grenzgänger Seeks Reflexive Methodology

    Directory of Open Access Journals (Sweden)

    Wolff-Michael Roth


    Full Text Available Reflexive Methodology reviews major strands of current thought in epistemology, philosophy, social science, and interpretive methods. The book falls short in that it neither does a thorough job reviewing the literature nor does it provide method-related advice useful to students. Grenzgängerin constitutes a collection of essays on a broad range of topics, but which are only loosely connected if at all. Drawing on DERRIDA and the notion of a historical science of the historical subject, I attempt to practice method, something I missed in both texts. I make explicit the historical nature of my own writing and the historical nature of my subject. I make explicit intertextuality and in the process practice reflexivity in the particular way I am writing. URN: urn:nbn:de:0114-fqs020328

  18. Motion and Walking Stabilization of Humanoids Using Sensory Reflex Control

    Directory of Open Access Journals (Sweden)

    Jong-Wook Kim


    Full Text Available Humanoid robots are versatile robot platforms that can carry out intelligent tasks and services for humans, including intimate interactions. For high mobility, a robust stabilization of motion including biped walking is crucial. This paper employs and elaborates on sensory reflex control to stabilize standing motion and biped walking using basic sensors such as an inertial measurement unit (IMU and a force-sensing resistor (FSR. Specifically, normalized zero-moment points processed from FSR data are used in the reflexive control of a simple motion of swinging the whole body while standing, and the measured inclination angle of the trunk, filtered from IMU data, is used for biped walking on a sloped floor. The proposed control scheme is validated through experiments with the commercial humanoid robot, ROBOTIS-OP.

  19. Inside Reflexive Management Learning in the Workplace: An Ethnographic Study


    Cotter, Richard J.


    This thesis generates new insights and understandings of the concept of reflexive management learning (RML). To date, most scholarship has taken the form of prescriptive theory suggesting what RML should be and should mean for managers and organisations. In the main, however, RML remains empirically under-theorised and as a result rather detached from real world contexts and from the practitioners that would constitute its intended learning audience. This thesis helps to rebalance the scho...

  20. Reflexivity, Knowledge and the Management of Potential Innovation

    DEFF Research Database (Denmark)

    Bordum, Anders


    In this article I will interpret John Deweys perspective on reflective thinking as if he were a philosopher of innovation management. From his pragmatist point of departure, the problems involved in knowledge-processes relevant to innovation are analysed and reconceptualised. On the basis...... as managing the production of new knowledge, that is of making the unjustified justified, and the unknown known. Keywords: Reflexivity, reflective thought, radical innovation, innovation management, potential innovation, Plato, John Dewey, epistemology, knowledge....

  1. The Danish CSR Reporting Requirement as Reflexive Law

    DEFF Research Database (Denmark)

    Buhmann, Karin


    With effect for financial years beginning January 2009 or later, the Danish Financial Statements Act and related governmental regulations require large Danish companies and institutional investors to submit an annual Corporate Social Responsibility (CSR) report. Through application of reflexive law...... history and reporting guidelines indicate a definite objective of drawing on the CSR paradigm to complement national substantive law, engaging company practice in the implementation of national public policy goals and in the extraterritorial implementation of public policy goals related to conditions...

  2. The Mammalian Diving Response: An Enigmatic Reflex to Preserve Life? (United States)


    The mammalian diving response is a remarkable behavior that overrides basic homeostatic reflexes. It is most studied in large aquatic mammals but is seen in all vertebrates. Pelagic mammals have developed several physiological adaptations to conserve intrinsic oxygen stores, but the apnea, bradycardia, and vasoconstriction is shared with those terrestrial and is neurally mediated. The adaptations of aquatic mammals are reviewed here as well as the neural control of cardiorespiratory physiology during diving in rodents. PMID:23997188

  3. Unilateral trachyonychia in a patient with reflex sympathetic dystrophy. (United States)

    Pucevich, Brian; Spencer, Lori; English, Joseph C


    Reflex sympathetic dystrophy (RSD) is a poorly understood neurovascular disorder characterized by pain, altered sensation, motor disturbance, soft tissue changes, vasomotor changes, and autonomic changes that occurs after trauma to an extremity. Unilateral leukonychia, Beau's lines, nailfold swelling, and nail clubbing have been an observed sequela of RSD. We present a case of a unilateral atypical trachyonychia occurring in the setting of RSD after traumatic fracture of a digit.

  4. A case of linear morphoea mistaken for reflex sympathetic dystrophy. (United States)

    Thng, Steven Tien Guan; Wong, Keryi


    Morphoea, or localised scleroderma, is a disease entity with poorly understood pathogenesis. Early diagnosis of the condition is crucial in order to prevent permanent morbidity. However, initial presentations of morphoea can be nonspecific and easily mistaken for other conditions, resulting in late treatment and permanent disability. We report a case of linear morphoea in a 22-year-old man who was initially diagnosed with reflex sympathetic dystrophy. By the time the diagnosis of morphoea was confirmed, the patient had already developed contractures.

  5. Reflex sympathetic dystrophy in the hands: clinical and scintigraphic criteria

    Energy Technology Data Exchange (ETDEWEB)

    Holder, L.E.; Mackinnon, S.E.


    In an attempt to establish specific scintigraphic criteria for the reflex sympathetic dystrophy syndrome (RSD) as defined by a group of specialized hand surgeons, 145 consecutive patients, 23 of whom had clinical RSD, underwent three phase radionuclide bone scanning (TPBS). Specific patterns for positive radionuclide angiogram, blood pool, and delayed images were established. The delayed images were sensitive (96%), specific (97%), and had a valuable negative predictive value (99%). It was concluded that TPBS could provide an objective marker for RSD.

  6. [Regional transient osteoporosis, and reflex sympathetic dystrophy: the same disease?]. (United States)

    Castellano, Karina; Plantalech, Luisa


    Complex regional pain syndrome, reflex sympathetic dystrophy, regional, transient and migratory osteoporosis, are known as a spectrum of medical conditions that present with pain, edema, erythema, localized osteoporosis and sometimes sympathetic dysfunction. Many factors which are present in these conditions, such as clinical presentation, radiologic findings and a variety of still unclear physiopathologic mechanisms are correlated. We propose that all these conditions are different periods of the same pathology.

  7. A reflexive exploration of two qualitative data coding techniques


    Erik Blair


    In an attempt to help find meaning within qualitative data, researchers commonly start by coding their data. There are a number of coding systems available to researchers and this reflexive account explores my reflections on the use of two such techniques. As part of a larger investigation, two pilot studies were undertaken as a means to examine the relative merits of open coding and template coding for examining transcripts. This article does not describe the research project per se but atte...

  8. Radiographic assessment of laryngeal reflexes in ketamine-anesthetized cats

    International Nuclear Information System (INIS)

    Robinson, E.P.; Johnston, G.R.


    The competence of the laryngeal closure reflexes of cats anesthetized with ketamine was assessed. Radiographic evaluations of the respiratory and digestive tracts were made after colloidal barium suspension was instilled into the pharynges of conscious and ketamine-anesthetized cats. There was a significant ketamine dose-related response of spread of contrast medium into the supraglottic laryngeal area and into the stomach 2 minutes after contrast medium was instilled into the pharynx (P less than 0.05). Cats did not aspirate contrast medium into the lower respiratory tract. Three ketamine-anesthetized cats aspirated contrast medium into the subglottic area of the larynx, and 2 of these cats also aspirated the material into the cranial part of the trachea. This material was coughed up and swallowed within 5 minutes. Transit time of contrast medium into the stomach seemed to be increased in 11 of the 15 cats given the larger dosages of ketamine (24, 36, 48 mg/kg of body weight), compared with that in conscious cats and those given ketamine at 12 mg/kg. Competent laryngeal protective reflexes in cats can be maintained with ketamine anesthesia. Contrast radiography could be used as a diagnostic aid in ketamine-anesthetized cats suspected of laryngeal reflex abnormalities

  9. Blink and masseter inhibitory reflexes in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Stamenović Jelena


    Full Text Available Background/Aim. Idiopathic Parkinson's disease (PD is a chronic, progressive, neurodegenerative disorder with prevalence from 60 to 187 per 100 000 persons in general population. The aim of the study was to determine the abnormalities of the blink reflex (BR and the masseter inhibitory reflex (MIR in parkinsonian patients, as indices of the functional status of brainstem neuronal network, and abnormality level dependence on disease progression. Methods. The investigation was conducted at the Clinic of Neurology, Clinical Center Niš, comprising a group of 60 subjects of both sexes, suffering from idiopathic Parkinson's disease in I-IV stages, according to the Hoehn and Yahr scale. The control group included 30 healthy subjects of both sexes and corresponding age. Testing of the patients was performed during the 'on' phase by registering MIR and BR. Results. Latency of polysynaptic R2 and R2' blink reflex responses and latency of polysynaptic S2 response, as well as a silent period of MIR, are linearly shortened in the subjects with PD, and more expressed in the subsequent stages of the disease compared to the control group. Conclusion. There is a positive correlation between the applied neurophysiological tests results and clinical stage of PD.

  10. Head Stabilization Reflex in Patients with Brain Stem Vascular Lesions

    Directory of Open Access Journals (Sweden)

    Ferah Kızılay


    Full Text Available OBJECTIVE: The head stabilization reflex (HSR elicited by stimulating the accessory nerve is an oligo-polysynaptic/plurisegmental flexor reflex, which brings the head back to its previous position in response to a variety of sudden head position changes. This reflex was studied in numerous diseases and was inhibited in patients with cerebellar lesions. The present study aimed to investigate how HSR is affected in patients with brain stem vascular lesions. METHODS: The study included 18 patients with brain stem vascular lesions and 18 normal control subjects. Concentric needle electrodes were inserted into the belly of both the sternocleidomastoid muscle and the accessory nerve, and were stimulated separately from the posterior triangle. In all, 8 HSR responses were recorded and mean onset latencies were measured. RESULTS: By stimulating the left accessory nerve in patients with brain stem vascular lesions, contralateral HSR could not be elicited. Similarly, by stimulating the right accessory nerve, contralateral HSR response was elicited only in 3 of the 18 patients. In contrast, stimulation of both the left and right accessory nerves elicited contralateral HSR in all the controls. CONCLUSION: HSR was inhibited in patients with brain stem vascular lesions. This observation shows that the descending pathways in the brain stem facilitate HSR in a similar fashion as the cerebellum was shown to do in a previous study

  11. A reflexive exploration of two qualitative data coding techniques

    Directory of Open Access Journals (Sweden)

    Erik Blair


    Full Text Available In an attempt to help find meaning within qualitative data, researchers commonly start by coding their data. There are a number of coding systems available to researchers and this reflexive account explores my reflections on the use of two such techniques. As part of a larger investigation, two pilot studies were undertaken as a means to examine the relative merits of open coding and template coding for examining transcripts. This article does not describe the research project per se but attempts to step back and offer a reflexive account of the development of data coding tools. Here I reflect upon and evaluate the two data coding techniques that were piloted, and discuss how using appropriate aspects of both led to the development of my final data coding approach. My exploration found there was no clear-cut ‘best’ option but that the data coding techniques needed to be reflexively-aligned to meet the specific needs of my project. This reflection suggests that, when coding qualitative data, researchers should be methodologically thoughtful when they attempt to apply any data coding technique; that they do not assume pre-established tools are aligned to their particular paradigm; and that they consider combining and refining established techniques as a means to define their own specific codes. DOI: 10.2458/azu_jmmss.v6i1.18772DOI: 10.2458/azu_jmmss.v6i1.18772

  12. Acoustic Reflex Screening of Conductive Hearing Loss for Third Window Disorders. (United States)

    Hong, Robert S; Metz, Christopher M; Bojrab, Dennis I; Babu, Seilesh C; Zappia, John; Sargent, Eric W; Chan, Eleanor Y; Naumann, Ilka C; LaRouere, Michael J


    This study examines the effectiveness of acoustic reflexes in screening for third window disorders (eg, superior semicircular canal dehiscence) prior to middle ear exploration for conductive hearing loss. Case series with chart review. Outpatient tertiary otology center. A review was performed of 212 ears with acoustic reflexes, performed as part of the evaluation of conductive hearing loss in patients without evidence of chronic otitis media. The etiology of hearing loss was determined from intraoperative findings and computed tomography imaging. The relationship between acoustic reflexes and conductive hearing loss etiology was assessed. Eighty-eight percent of ears (166 of 189) demonstrating absence of all acoustic reflexes had an ossicular etiology of conductive hearing loss. Fifty-two percent of ears (12 of 23) with at least 1 detectable acoustic reflex had a nonossicular etiology. The positive and negative predictive values for an ossicular etiology were 89% and 57% when acoustic reflexes were used alone for screening, 89% and 39% when third window symptoms were used alone, and 94% and 71% when reflexes and symptoms were used together, respectively. Acoustic reflex testing is an effective means of screening for third window disorders in patients with a conductive hearing loss. Questioning for third window symptoms should complement screening. The detection of even 1 acoustic reflex or third window symptom (regardless of reflex status) should prompt further workup prior to middle ear exploration. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  13. The Correlation between Modified Ashworth Scale and Biceps T-reflex and Inter-rater and Intra-rater Reliability of Biceps T-reflex. (United States)

    Min, Ji Hong; Shin, Yong-Il; Joa, Kyung Lim; Ko, Sung Hwa; Shin, Myung Jun; Chang, Jae Hyeok; Ko, Hyun-Yoon


    To establish a correlation between the modified Ashworth scale (MAS) and amplitude and latency of T-reflex and to demonstrate inter-rater and intra-rater reliability of the T-reflex of the biceps muscle for assessing spasticity after stroke. A total of 21 patients with hemiplegia and spasticity after ischemic stroke were enrolled for this study. The spasticity of biceps muscle was evaluated by an occupational therapist using the MAS. The mean value of manual muscle test of biceps muscles was 2.3±0.79. Latency and amplitude of T-reflex were recorded from biceps muscles by two physicians. The onset latency and peak to peak amplitude of the mean of 5 big T-reflex were measured. The examinations were carried out by two physicians at the same time to evaluate the inter-rater reliability. Further, one of the physicians performed the examination again after one week to evaluate the intra-rater reliability. The correlations between MAS and T-reflex, and the intra- and inter-rater reliability of biceps T-reflex were established by calculating the Spearman correlation coefficients and the intra-class correlation coefficients (ICCs). Amplitude of the biceps T-reflex increased with increasing level of MAS (r(s)=0.464 and 0.573, respectively, p<0.01). ICCs of latency and amplitude of biceps T-reflex were 0.914 and 0.822. The Spearman correlation coefficients of latency and amplitude of biceps T-reflex were 0.937 and 0.635, respectively (p<0.01). Biceps T-reflex demonstrates a good quantitative measurement and correlation tool with MAS for spasticity, and also shows acceptable inter- and intra-rater reliability, which can be used for patients with spasticity after stroke.

  14. Interlimb reflexes following ipsilateral knee joint rotations are suppressed in an unstable walking environment

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Sinkjær, Thomas


    Interlimb reflexes play an important role in human walking, such as when dynamic stability is threatened by external perturbations or changes in the walking surface. For example, we have previously shown that interlimb reflexes in the contralateral biceps femoris (cBF) following ipsilateral knee (iKnee...... on experiments investigating intra- and interlimb cutaneous reflexes and soleus H-reflexes (Llewellyn et al., 1990; Haridas et al., 2005; 2006; Krauss and Misiaszek, 2007), we hypothesized that the amplitude of interlimb reflexes following iKnee perturbations is altered when walking in an unstable environment....... To test this, interlimb reflexes were elicited in participants (n = 6) by either iKnee extension rotations during the late stance phase (50%) of the gait cycle or iKnee flexion rotations during the mid-swing phase (80%). The iKnee perturbations were applied while the participants walked normally...

  15. The Gateway Reflex, a Novel Neuro-Immune Interaction for the Regulation of Regional Vessels

    Directory of Open Access Journals (Sweden)

    Yuki Tanaka


    Full Text Available The gateway reflex is a new phenomenon that explains how immune cells bypass the blood–brain barrier to infiltrate the central nervous system (CNS and trigger neuroinflammation. To date, four examples of gateway reflexes have been discovered, each described by the stimulus that evokes the reflex. Gravity, electricity, pain, and stress have all been found to create gateways at specific regions of the CNS. The gateway reflex, the most recently discovered of the four, has also been shown to upset the homeostasis of organs in the periphery through its action on the CNS. These reflexes provide novel therapeutic targets for the control of local neuroinflammation and organ function. Each gateway reflex is activated by different neural activations and induces inflmammation at different regions in the CNS. Therefore, it is theoretically possible to manipulate each independently, providing a novel therapeutic strategy to control local neuroinflammation and peripheral organ homeostasis.

  16. Changes in soleus H-reflex during walking in middle-aged, healthy subjects

    DEFF Research Database (Denmark)

    Raffalt, Peter C; Alkjær, Tine; Simonsen, Erik B


    and tibialis anterior muscles, and EMG/H-reflex gain were measured during 4-km/h treadmill walking. RESULTS: The normalized H-reflex amplitude was lower in the swing phase for the middle-aged group, and there was no difference in muscle activity. EMG/H-reflex gain did not differ between groups. CONCLUSIONS: H......INTRODUCTION: To assess the effect of aging on stretch reflex modulation during walking, soleus H-reflexes obtained in 15 middle-aged (mean age 56.4±6.9 years) and 15 young (mean age 23.7±3.9 years) subjects were compared. METHODS: The H-reflex amplitude, muscle activity (EMG) of the soleus...

  17. The Gateway Reflex, a Novel Neuro-Immune Interaction for the Regulation of Regional Vessels. (United States)

    Tanaka, Yuki; Arima, Yasunobu; Kamimura, Daisuke; Murakami, Masaaki


    The gateway reflex is a new phenomenon that explains how immune cells bypass the blood-brain barrier to infiltrate the central nervous system (CNS) and trigger neuroinflammation. To date, four examples of gateway reflexes have been discovered, each described by the stimulus that evokes the reflex. Gravity, electricity, pain, and stress have all been found to create gateways at specific regions of the CNS. The gateway reflex, the most recently discovered of the four, has also been shown to upset the homeostasis of organs in the periphery through its action on the CNS. These reflexes provide novel therapeutic targets for the control of local neuroinflammation and organ function. Each gateway reflex is activated by different neural activations and induces inflmammation at different regions in the CNS. Therefore, it is theoretically possible to manipulate each independently, providing a novel therapeutic strategy to control local neuroinflammation and peripheral organ homeostasis.

  18. Rank-one operators in reflexive one-sided A-submodules

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    submodule of B(H) for a nest algebra A is of the above form. In [4], Han Deguang proved that this is also true for any reflexive algebra A, which is σ-weakly generated by rank-one operators in itself. The purpose of this paper is to show that any reflexive right A-submodule and ∗-reflexive left A-submodule of a unital operator ...

  19. VizieR Online Data Catalog: RefleX : X-ray-tracing code (Paltani+, 2017) (United States)

    Paltani, S.; Ricci, C.


    We provide here the RefleX executable, for both Linux and MacOSX, together with the User Manual and example script file and output file Running (for instance): reflex_linux will produce the file reflex.out Note that the results may differ slightly depending on the OS, because of slight differences in some implementations numerical computations. The difference are scientifically meaningless. (5 data files).

  20. Training specific adaptations of H- and stretch reflexes in human soleus muscle


    Gruber, Markus; Taube, Wolfgang; Gollhofer, Albert; Beck, Sandra; Amtage, Florian; Schubert, Martin


    The authors investigated the effect of physical exercise on reflex excitability in a controlled intervention study. Healthy participants (N = 21) performed 4 weeks of either power training (ballistic strength training) or balance training (sensorimotor training [SMT]). Both training regimens enhanced balance control and rate of force development, whereas reductions in peak-to-peak amplitudes of stretch reflexes and in the ratio of the maximum Hoffman reflex to the maximum efferent motor respo...

  1. Deprivation and Recovery of Sleep in Succession Enhances Reflexive Motor Behavior


    Sprenger, Andreas; Weber, Frederik D.; Machner, Bjoern; Talamo, Silke; Scheffelmeier, Sabine; Bethke, Judith; Helmchen, Christoph; Gais, Steffen; Kimmig, Hubert; Born, Jan


    Sleep deprivation impairs inhibitory control over reflexive behavior, and this impairment is commonly assumed to dissipate after recovery sleep. Contrary to this belief, here we show that fast reflexive behaviors, when practiced during sleep deprivation, is consolidated across recovery sleep and, thereby, becomes preserved. As a model for the study of sleep effects on prefrontal cortex-mediated inhibitory control in humans, we examined reflexive saccadic eye movements (express saccades), as w...

  2. Ontogenetic Development of Vestibulo-Ocular Reflexes in Amphibians. (United States)

    Branoner, Francisco; Chagnaud, Boris P; Straka, Hans


    Vestibulo-ocular reflexes (VOR) ensure gaze stability during locomotion and passively induced head/body movements. In precocial vertebrates such as amphibians, vestibular reflexes are required very early at the onset of locomotor activity. While the formation of inner ears and the assembly of sensory-motor pathways is largely completed soon after hatching, angular and translational/tilt VOR display differential functional onsets and mature with different time courses. Otolith-derived eye movements appear immediately after hatching, whereas the appearance and progressive amelioration of semicircular canal-evoked eye movements is delayed and dependent on the acquisition of sufficiently large semicircular canal diameters. Moreover, semicircular canal functionality is also required to tune the initially omnidirectional otolith-derived VOR. The tuning is due to a reinforcement of those vestibulo-ocular connections that are co-activated by semicircular canal and otolith inputs during natural head/body motion. This suggests that molecular mechanisms initially guide the basic ontogenetic wiring, whereas semicircular canal-dependent activity is required to establish the spatio-temporal specificity of the reflex. While a robust VOR is activated during passive head/body movements, locomotor efference copies provide the major source for compensatory eye movements during tail- and limb-based swimming of larval and adult frogs. The integration of active/passive motion-related signals for gaze stabilization occurs in central vestibular neurons that are arranged as segmentally iterated functional groups along rhombomere 1-8. However, at variance with the topographic maps of most other sensory systems, the sensory-motor transformation of motion-related signals occurs in segmentally specific neuronal groups defined by the extraocular motor output targets.

  3. Startle reflex modulation by affective face "Emoji" pictographs. (United States)

    Aluja, Anton; Balada, Ferran; Blanco, Eduardo; Lucas, Ignacio; Blanch, Angel


    The current research was designed to assess possible differences in the emotional content of pleasant and unpleasant face emoji using acoustically evoked eyeblink startle reflex response. Stimuli were selected from Emojipedia Webpage. First, we assessed these stimuli with a previous independent sample of 190 undergraduate students (46 males and 144 females) mean age of 21.43 years (SD 3.89). A principal axis method was performed using the 30 selected emoji faces, extracting two factors (15 pleasant and 15 unpleasant emoji). Second, we measured the acoustic startle reflex modulation in 53 young adult women [mean age 22.13 years (SD 4.3)] during the viewing of each of the 30 emoji emotional faces in the context of the theory of motivation and emotion proposed by Lang (1995), but considering only the valence dimension. We expected to find higher acoustically evoked startle responses when viewing unpleasant emoji and lower responses for pleasant ones, similarly to the results obtained in the studies using human faces as emotional stimulus. An ANOVA was conducted to compare acoustic startle responses associated with pleasant and unpleasant emoji. Results yielded main effects for picture valence (λ = 0.80, F(1, 50) = 12.80, p = .001, η 2  = 0.20). Post-hoc t test analysis indicated significant differences in the startle response between unpleasant (50.95 ± 1.75) and pleasant (49.14 ± 2.49) emoji (t (52) = 3.59, p = .001), with a Cohen's d = 0.495. Viewing affective facial emoji expressions modulates the acoustic startle reflex response according to their emotional content.

  4. Modification of Otolith Reflex Asymmetries Following Space Flight (United States)

    Clarke, Andrew H.; Schoenfeld, Uwe; Wood, Scott J.


    We hypothesize that changes in otolith-mediated reflexes adapted for microgravity contribute to perceptual, gaze and postural disturbances upon return to Earth s gravity. Our goal was to determine pre- versus post-fight differences in unilateral otolith reflexes that reflect these adaptive changes. This study represents the first comprehensive examination of unilateral otolith function following space flight. Ten astronauts participated in unilateral otolith function tests three times pre-flight and up to four times after Shuttle flights from landing day through the subsequent 10 days. During unilateral centrifugation (UC, +/- 3.5cm at 400deg/s), utricular function was examined by the perceptual changes reflected by the subjective visual vertical (SVV) and by video-oculographic measurement of the otolith-mediated ocular counter-roll (OOR). Unilateral saccular reflexes were recorded by measurement of collic Vestibular Evoked Myogenic Potential (cVEMP). Although data from a few subjects were not obtained early post-flight, a general increase in asymmetry of otolith responses was observed on landing day relative to pre-flight baseline, with a subsequent reversal in asymmetry within 2-3 days. Recovery to baseline levels was achieved within 10 days. This fluctuation in the asymmetry measures appeared strongest for SVV, in a consistent direction for OOR, and in an opposite direction for cVEMP. These results are consistent with our hypothesis that space flight results in adaptive changes in central nervous system processing of otolith input. Adaptation to microgravity may reveal asymmetries in otolith function upon to return to Earth that were not detected prior to the flight due to compensatory mechanisms.

  5. Proximally evoked soleus H-reflex to S1 nerve root stimulation in sensory neuronopathies (ganglionopathies). (United States)

    Zhu, Dong-Qing; Zhu, Yu; Qiao, Kai; Zheng, Chao-Jun; Bradley, Scott; Weber, Robert; Chen, Xiang-Jun


    Sensory neuronopathy (SNN) mimics distal sensory axonopathy. The conventional H-reflex elicited by tibial nerve stimulation (tibial H-reflex) is usually abnormal in both conditions. We evaluated the proximally evoked soleus H-reflex in response to S1 nerve root stimulation (S1 foramen H-reflex) in SNN. Eleven patients with SNN and 6 with distal sensory axonopathy were studied. Tibial and S1 foramen H-reflexes were performed bilaterally in each patient. Tibial and S1 foramen H-reflexes were absent bilaterally in all patients with SNN. In the patients with distal sensory axonopathy, tibial H-reflexes were absent in 4 and demonstrated prolonged latencies in 2, but S1 foramen H-reflexes were normal. Characteristic absence of the H-reflex after both proximal and distal stimulation reflects primary loss of dorsal root ganglion (DRG) neurons and the distinct non-length-dependent impairment of sensory nerve fibers in SNN. Copyright © 2013 Wiley Periodicals, Inc.

  6. Implementation of an iPhone wireless accelerometer application for the quantification of reflex response. (United States)

    LeMoyne, Robert; Mastroianni, Timothy; Grundfest, Warren; Nishikawa, Kiisa


    The patellar tendon reflex represents an inherent aspect of the standard neurological evaluation. The features of the reflex response provide initial perspective regarding the status of the nervous system. An iPhone wireless accelerometer application integrated with a potential energy impact pendulum attached to a reflex hammer has been successfully developed, tested, and evaluated for quantifying the patellar tendon reflex. The iPhone functions as a wireless accelerometer platform. The wide coverage range of the iPhone enables the quantification of reflex response samples in rural and remote settings. The iPhone has the capacity to transmit the reflex response acceleration waveform by wireless transmission through email. Automated post-processing of the acceleration waveform provides feature extraction of the maximum acceleration of the reflex response ascertained after evoking the patellar tendon reflex. The iPhone wireless accelerometer application demonstrated the utility of the smartphone as a biomedical device, while providing accurate and consistent quantification of the reflex response.

  7. Reflexivity: The Creation of Liminal Spaces--Researchers, Participants, and Research Encounters. (United States)

    Enosh, Guy; Ben-Ari, Adital


    Reflexivity is defined as the constant movement between being in the phenomenon and stepping outside of it. In this article, we specify three foci of reflexivity--the researcher, the participant, and the encounter--for exploring the interview process as a dialogic liminal space of mutual reflection between researcher and participant. Whereas researchers' reflexivity has been discussed extensively in the professional discourse, participants' reflexivity has not received adequate scholarly attention, nor has the promise inherent in reflective processes occurring within the encounter. © The Author(s) 2015.

  8. Bone scintigraphy in the reflex sympathetic dystrophy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, F.; Soin, J.S.; Ryan, L.M.; Carrera, G.F.; Wortmann, R.L.


    Sixty-four consecutive patients were studied for possible reflex sympathetic dystrophy syndrome (RSDS). They were divided into five groups, based upon specific clinical criteria, and the radiographic and scintigraphic findings in each group were examined. Osteoporosis was the most common radiographic abnormality. Scintigraphic abnormalities were noted in 60% of RSDS patients but in only 7% of the others. These findings included increased blood flow and enhanced periarticular radionuclide activity in the affected extremity. The scan may reflect an active, potentially reversible disorder of local blood flow in RSDS. Furthermore, the scintigraphic patterns may be useful in the diagnosis and in predicting which patients are likely to respond to systemic steroid therapy.

  9. Reflex sympathetic dystrophy: an enigmatic improvement with spinal manipulation (United States)

    Bortolotto, James


    Reflex Sympathetic Dystrophy (RSD) or complex regional pain syndrome, is an extremely painful and disabling condition commonly seen following trauma. Its early recognition and treatment is most critical for a favorable prognosis. Although its diagnosis and treatments vary, neuroblockade is the treatment of choice. Very little has been reported in the literature in regards to manipulation as an early treatment modality to improve joint mobility and reduce pain and future disability. This case report reviews one case presentation of RSD where dramatic results followed cervical spine manipulation.

  10. Semiotic scaffolding of the social self in reflexivity and friendship

    DEFF Research Database (Denmark)

    Emmeche, Claus


    Margaret Archer’s empirical and theoretical work on the interplay between individual subjectivity, social structure and interpersonal relations in a dynamics of human agency. It is shown that although processes of reflexivity and friendship can indeed be seen as instances of semiotic scaffolding......The individual and social formation of a human self, from its emergence in early childhood through adolescence to adult life, has been described within philosophy, psychology and sociology as a product of developmental and social processes mediating a linguistic and social world. Semiotic...

  11. Simulating Muscle-Reflex Dynamics in a Simple Hopping Robot (United States)

    Seyfarth, Andre; Kalveram, Karl Theodor; Geyer, Hartmut

    In legged systems, springy legs facilitate gaits with subsequent contact and flight phases. Here, we test whether electrical motors can generate leg behaviors suitable for stable hopping. We built a vertically operating sledge actuated by a motor-driven leg. The motor torque simulates either a linear leg spring or a muscle-reflex system. For stable hopping significant energy supply was required after midstance. This was achieved by enhancing leg stiffness or by continuously applying positive force feedback to the simulated muscle. The muscle properties combined with positive force feedback result in spring-like behavior which enables stable hopping with adjustable hopping height.

  12. Radionuclide bone scanning in reflex sympathetic dystrophy syndrome. L'exploration scintigraphique dans l'algodystrophie sympathique reflexe

    Energy Technology Data Exchange (ETDEWEB)

    Manicourt, D.H. (Louvain Univ., Brussels (Belgium). Cliniques Universitaires St. Luc)


    Three-phase radionuclide bone scanning is extremely useful in patients with suspected reflex sympathetic dystrophy syndrome. The functional data it provides can be analyzed either visually or semiquantitatively. Its many advantages include good sensitivity; however, its specificity varies substantially across sites and clinical patterns. The main differential diagnoses are reviewed. Semiquantitative analysis of scintigram data is of limited diagnostic usefulness but provides valuable pathophysiological information and can be helpful in guiding therapeutic decisions. Semiquantitative analysis has demonstrated that the severity and duration of changes in radionuclide uptake vary widely across sites and that effects on scintigraphic parameters differ between calcitonin and pamidronate. (author). 85 refs., 10 figs., 6 tabs.

  13. A new method for non-invasive biomass determination based on stereo photogrammetry. (United States)

    Syngelaki, Maria; Hardner, Matthias; Oberthuer, Patrick; Bley, Thomas; Schneider, Danilo; Lenk, Felix


    A novel, non-destructive method for the biomass estimation of biological samples on culture dishes was developed. To achieve this, a photogrammetric system, which consists of a digital single-lens reflex camera (DSLR), an illuminated platform where the culture dishes are positioned and an Arduino board which controls the capturing process, was constructed. The camera was mounted on a holder which set the camera at different title angles and the platform rotated, to capture images from different directions. A software, based on stereo photogrammetry, was developed for the three-dimensional (3D) reconstruction of the samples. The proof-of-concept was demonstrated in a series of experiments with plant tissue cultures and specifically with calli cultures of Salvia fruticosa and Ocimum basilicum. For a period of 14 days images of these cultures were acquired and 3D-reconstructions and volumetric data were obtained. The volumetric data correlated well with the experimental measurements and made the calculation of the specific growth rate, µ max , possible. The µ max value for S. fruticosa samples was 0.14 day -1 and for O. basilicum 0.16 day -1 . The developed method demonstrated the high potential of this photogrammetric approach in the biological sciences.

  14. Imaging optical scattering of butterfly wing scales with a microscope. (United States)

    Fu, Jinxin; Yoon, Beom-Jin; Park, Jung Ok; Srinivasarao, Mohan


    A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as Morpho butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of Morpho butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of Morpho rhetenor by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of Morpho cypris . In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.

  15. A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds. (United States)

    Gabara, Grzegorz; Sawicki, Piotr


    The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011.

  16. Effect of applied voltage on surface properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

    Energy Technology Data Exchange (ETDEWEB)

    Chuan, Lee Te, E-mail:; Rathi, Muhammad Fareez Mohamad, E-mail:; Abidin, Muhamad Yusuf Zainal, E-mail:; Abdullah, Hasan Zuhudi, E-mail:; Idris, Maizlinda Izwana, E-mail: [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)


    Anodic oxidation is a surface modification method which combines electric field driven metal and oxygen ion diffusion for formation of oxide layer on the anode surface. This method has been widely used to modify the surface morphology of biomaterial especially titanium. This study aimed to investigate the effect of applied voltage on titanium. Specifically, the titanium foil was anodised in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA) with different applied voltage (50-350 V), electrolyte concentration (0.04 M β-GP + 0.4 M CA), anodising time (10minutes) and current density (50 and 70{sup −2}) at room temperature. Surface oxide properties of anodised titanium were characterised by digital single-lens reflex camera (DSLR camera), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM). At lower applied voltage (≤150 V), surface of titanium foils were relatively smooth. With increasing applied voltage (≥250 V), the oxide layer became more porous and donut-shaped pores were formed on the surface of titanium foils. The AFM results indicated that the surface roughness of anodised titanium increases with increasing of applied voltage. The porous and rough surface is able to promote the osseointegration and reduce the suffering time of patient.

  17. Measuring the spatial resolution of an optical system in an undergraduate optics laboratory (United States)

    Leung, Calvin; Donnelly, T. D.


    Two methods of quantifying the spatial resolution of a camera are described, performed, and compared, with the objective of designing an imaging-system experiment for students in an undergraduate optics laboratory. With the goal of characterizing the resolution of a typical digital single-lens reflex (DSLR) camera, we motivate, introduce, and show agreement between traditional test-target contrast measurements and the technique of using Fourier analysis to obtain the modulation transfer function (MTF). The advantages and drawbacks of each method are compared. Finally, we explore the rich optical physics at work in the camera system by calculating the MTF as a function of wavelength and f-number. For example, we find that the Canon 40D demonstrates better spatial resolution at short wavelengths, in accordance with scalar diffraction theory, but is not diffraction-limited, being significantly affected by spherical aberration. The experiment and data analysis routines described here can be built and written in an undergraduate optics lab setting.

  18. SEM-microphotogrammetry, a new take on an old method for generating high-resolution 3D models from SEM images. (United States)

    Ball, A D; Job, P A; Walker, A E L


    The method we present here uses a scanning electron microscope programmed via macros to automatically capture dozens of images at suitable angles to generate accurate, detailed three-dimensional (3D) surface models with micron-scale resolution. We demonstrate that it is possible to use these Scanning Electron Microscope (SEM) images in conjunction with commercially available software originally developed for photogrammetry reconstructions from Digital Single Lens Reflex (DSLR) cameras and to reconstruct 3D models of the specimen. These 3D models can then be exported as polygon meshes and eventually 3D printed. This technique offers the potential to obtain data suitable to reconstruct very tiny features (e.g. diatoms, butterfly scales and mineral fabrics) at nanometre resolution. Ultimately, we foresee this as being a useful tool for better understanding spatial relationships at very high resolution. However, our motivation is also to use it to produce 3D models to be used in public outreach events and exhibitions, especially for the blind or partially sighted. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  19. Manual compression and reflex syncope in native renal biopsy. (United States)

    Takeuchi, Yoichi; Ojima, Yoshie; Kagaya, Saeko; Aoki, Satoshi; Nagasawa, Tasuku


    Complications associated with diagnostic native percutaneous renal biopsy (PRB) must be minimized. While life threatening major complications has been extensively investigated, there is little discussion regarding minor bleeding complications, such as a transient hypotension, which directly affect patients' quality of life. There is also little evidence supporting the need for conventional manual compression following PRB. Therefore, this study evaluated the relationship between minor and major complications incidence in patients following PRB with or without compression. This single-center, retrospective study included 456 patients (compression group: n = 71; observation group: n = 385). The compression group completed 15 min of manual compression and 4 h of subsequent strict bed rest with abdominal bandage. The observation group completed 2 h of strict bed rest only. The primary outcome of interest was transient symptomatic hypotension (minor event). Of the 456 patients, 26 patients encountered intraoperative and postoperative transient hypotension, which were considered reflex syncope without tachycardia. Univariate analysis showed that symptomatic transient hypotension was significantly associated with compression. This association remained significant, even after adjustment of covariates using multivariate logistic regression analysis (adjusted odds ratio 3.27; 95% confidential interval 1.36-7.82; P = 0.0078). Manual compression and abdominal bandage significantly increased the frequency of reflex syncope during native PRB. It is necessary to consider the potential benefit and risk of compression maneuvers for each patient undergoing this procedure.

  20. Modulation of the startle reflex by pleasant and unpleasant music. (United States)

    Roy, Mathieu; Mailhot, Jean-Philippe; Gosselin, Nathalie; Paquette, Sébastien; Peretz, Isabelle


    The issue of emotional feelings to music is the object of a classic debate in music psychology. Emotivists argue that emotions are really felt in response to music, whereas cognitivists believe that music is only representative of emotions. Psychophysiological recordings of emotional feelings to music might help to resolve the debate, but past studies have failed to show clear and consistent differences between musical excerpts of different emotional valence. Here, we compared the effects of pleasant and unpleasant musical excerpts on the startle eye blink reflex and associated body markers (such as the corrugator and zygomatic activity, skin conductance level and heart rate). The startle eye blink amplitude was larger and its latency was shorter during unpleasant compared with pleasant music, suggesting that the defensive emotional system was indeed modulated by music. Corrugator activity was also enhanced during unpleasant music, whereas skin conductance level was higher for pleasant excerpts. The startle reflex was the response that contributed the most in distinguishing pleasant and unpleasant music. Taken together, these results provide strong evidence that emotions were felt in response to music, supporting the emotivist stance.

  1. Agentive reflexive clitics and transitive 'se' constructions in Spanish

    Directory of Open Access Journals (Sweden)

    Grant Armstrong


    Full Text Available This paper investigates the structure of transitive sentences that contain a non-doubling reflexive clitic such as Juan se lavó todos los platos and María se leyó un libro. Though these are traditionally labelled unselected (non-core agreeing datives or aspectual datives, I argue that this label obscures a relevant difference between two classes of constructions. agentive reflexive clitic (= ARC constructions are characterized by a uniform set of effects on the external argument (= it must be an agent and the aspectual interpretation of the VP (= it must be an accomplishment. On the other hand, transitive se clitic (= TSC constructions do not impose any type of uniform restrictions on the kind of external argument they take or on the aspectual interpretation of the VP. I propose that the difference between these two constructions may be captured by treating se in the ARC construction as the realization of a special vDO head, based on an idea in Folli & Harley (2005, while se in the TSC construction is generated in the complement position of the verb and incorporates into V, forming a complex predicate, following work by De Cuyper (2006, MacDonald (2004, 2008 and MacDonald & Huidobro (2010. It is shown that many of the empirical and theoretical disagreements that plague the literature on the role of non-doubling se in transitive sentences have a simple solution given the new division established here

  2. Agency, reflexivity and risk: cosmopolitan, neurotic or prudential citizen? (United States)

    Walklate, Sandra; Mythen, Gabriel


    The purpose of this paper is to critically examine the turn to risk within sociology and to survey the relationship between structure and agency as conceived by popular strands of risk theorizing. To this end, we appraise the risk society, culture of fear and governmentality perspectives and we consider the different imaginings of the citizen constructed by each of these approaches. The paper goes on to explore what each of these visions of citizenship implies for understandings of the structure/agency dynamic as it pertains to the question of reflexivity. In order to transcend uni-dimensional notions of citizenship and to reinvigorate sociological debates about risk, we call for conceptual analyses that are contextually rooted. Exampling the importance of knowledge contests around contemporary security threats and warnings of the deleterious effects of pre-emptive modes of regulation that derive from the 'risk turn' within social science, we argue for a more nuanced embrace of reflexivity within risk theorising in order to facilitate a more dynamic critique of the images of citizenship that such theorizing promotes.

  3. Revisiting global body politics in Nepal: A reflexive analysis. (United States)

    Harcourt, Wendy


    Using the example of a human rights training in Nepal, the author looks at global body politics in a reflexive piece on her engagement in development practices that translate western feminist ideas on gender inequality and empowerment via UN human rights policies into non-western contexts. It firsts look at postcolonial and critical literature on feminist engagement in gender and development processes including a discussion on the concept of global body politics before examining briefly the framing of gender-based violence in Nepal. The core of the paper is a reflexive analysis and interrogation of the training in Nepal in order to bring out the tensions and contradictions around western developmental, feminist and human rights discourses. The discussion looks at how difficult it is for feminist, human rights and developmental discourses and practices to unmoor themselves from the notion of the 'expert' and those who do the rights/work/righting rights training and those who are perennially seen as requiring training. The conclusion reflects on possibilities of other epistemic practices found in intercultural dialogues.

  4. Accuracy of Marginal Reflex Distance Measurements in Eyelid Surgery. (United States)

    Nemet, Arie Y


    The marginal reflex distance (MRD), the position of the eyelids with the eyes in the primary position, is fundamental to patient assessment and surgery choice in facial and ophthalmic plastic surgery. This study compares the accuracy of handheld ruler and slit lamp biomicroscope measurements of the MRD1 in patients with blepharoptosis. This is a prospective study of 85 consecutive patients who were referred to our oculoplastic clinic between 2011 and 2013 for unilateral or bilateral ptosis repair. The MRD1 was measured by 2 techniques: 1. With the use of a penlight to illuminate the cornea, the corneal light reflex is observed, and the distance between the cornea and the upper lid margin is recorded. 2. Slit lamp biomicroscope assessment. A comparison between those 2 methods was performed. The mean (SD) MRD1 was 1.18 (1.11) mm and 1.06 (1.18) mm with a penlight and a slit lamp, respectively. There was a significant difference between the 2 measurements, but they were highly correlated in the paired t-test and the Wilcoxon test. The intraclass correlation coefficient was 0.984, representing excellent reliability. The MRD1 measured by a skilled clinician yields reliable results using a penlight and a ruler. In some cases, measurement of eyelid heights (palpebral fissure, MRD1, brow position) is challenging. The use of a slit lamp biomicroscope and a close front photograph may help determine accurate measurements.

  5. Stretched, jumped, and fell: an fMRI investigation of reflexive verbs and other intransitives. (United States)

    Shetreet, Einat; Friedmann, Naama


    This study used fMRI to inform a debate between two theories concerning the representation of reflexive verbs. Reflexives are verbs that denote an action that the subject applies on herself (e.g., The woman stretched). These verbs are derived by a lexical operation that creates a reflexive from its transitive counterpart. Theories differ with respect to which thematic role is reduced by the lexical operation: the agent or the theme, and, consequently, whether the construction of sentences with reflexives in subject-verb order includes movement of the object to the subject position. To test this, we compared reflexive verbs with unaccusative verbs (e.g., The woman fell), and with unergative verbs (e.g., The woman jumped). Unaccusatives are derived by reduction of the role of the agent, and thus SV sentences with unaccusatives include movement to subject position. Unergatives do not undergo lexical operations and do not involve movement in SV sentences. The reflexives behaved like unergatives, and differently from unaccusatives: the activation pattern of unaccusatives compared with reflexives showed similar cortical pattern to that of unaccusatives compared with unergatives, with activations in the left inferior frontal gyrus and the left middle temporal gyrus (MTG). Comparing reflexives and unergatives revealed activation in the right MTG. These results indicate that reflexives differ from unaccusatives in their derivation. That is, reflexives do not involve the reduction of the agent of the parallel transitive, and hence no syntactic movement is involved in sentences in which the subject precedes the reflexive verb. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. H-reflex up-conditioning encourages recovery of EMG activity and H-reflexes after sciatic nerve transection and repair in rats. (United States)

    Chen, Yi; Wang, Yu; Chen, Lu; Sun, Chenyou; English, Arthur W; Wolpaw, Jonathan R; Chen, Xiang Yang


    Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 d to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals [i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)] on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair.

  7. Manual therapy directed at the knee or lumbopelvic region does not influence quadriceps spinal reflex excitability. (United States)

    Grindstaff, Terry L; Pietrosimone, Brian G; Sauer, Lindsay D; Kerrigan, D Casey; Patrie, James T; Hertel, Jay; Ingersoll, Christopher D


    Manual therapies, directed to the knee and lumbopelvic region, have demonstrated the ability to improve neuromuscular quadriceps function in individuals with knee pathology. It remains unknown if manual therapies may alter impaired spinal reflex excitability, thus identifying a potential mechanism in which manual therapy may improve neuromuscular function following knee injury. To determine the effect of local and distant mobilisation/manipulation interventions on quadriceps spinal reflex excitability. Seventy-five individuals with a history of knee joint injury and current quadriceps inhibition volunteered for this study. Participants were randomised to one of five intervention groups: lumbopelvic manipulation (grade V), lumbopelvic manipulation positioning (no thrust), grade IV patellar mobilisation, grade I patellar mobilisation, and control (no treatment). Changes in spinal reflex excitability were quantified by assessing the Hoffmann reflex (H-reflex), presynaptic, and postsynaptic excitability. A hierarchical linear-mixed model for repeated measures was performed to compare changes in outcome variables between groups over time (pre, post 0, 30, 60, 90 min). There were no significant differences in H-reflex, presynaptic, or postsynaptic excitability between groups across time. Manual therapies directed to the knee or lumbopelvic region did not acutely change quadriceps spinal reflex excitability. Although manual therapies may improve impairments and functional outcomes the underlying mechanism does not appear to be related to changes in spinal reflex excitability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Anesthetic management of the trigeminocardiac reflex during mesiodens removal-a case report. (United States)

    Webb, Michael D; Unkel, John H


    We describe a case in which reflection of a palatal flap for removal of a mesiodens is presented as the triggering factor for bradycardia caused by stimulation of the trigeminocardiac reflex. The management of the case, as well as the reflex arc, is discussed.

  9. Anesthetic Management of the Trigeminocardiac Reflex During Mesiodens Removal—A Case Report (United States)

    Webb, Michael D; Unkel, John H


    We describe a case in which reflection of a palatal flap for removal of a mesiodens is presented as the triggering factor for bradycardia caused by stimulation of the trigeminocardiac reflex. The management of the case, as well as the reflex arc, is discussed. PMID:17352528

  10. Rank-one operators in reflexive one-sided A-submodules

    Indian Academy of Sciences (India)

    In this paper, we first characterize reflexive one-sided A -submodules U of a unital operator algebra A in B ( H ) completely. Furthermore we investigate the invariant subspace lattice Lat R and the reflexive hull Ref R , where R is the submodule generated by rank-one operators in U ; in particular, if L is a subspace lattice, we ...

  11. On reflexivity and the conduct of the self in everyday life: reflections on Bourdieu and Archer. (United States)

    Akram, Sadiya; Hogan, Anthony


    This article provides a critique of the concept of reflexivity in social theory today and argues against the tendency to define agency exclusively in terms of reflexivity. Margaret Archer, in particular, is highlighted as a key proponent of this thesis. Archer argues that late modernity is characterized by reflexivity but, in our view, this position neglects the impact of more enduring aspects of agency, such as the routinization of social life and the role of the taken-for-granted. These concepts were pivotal to Bourdieu and Giddens' theorization of everyday life and action and to Foucault's understanding of technologies of the self. We offer Bourdieu's habitus as a more nuanced approach to theorizing agency, and provide an alternative account of reflexivity. Whilst accepting that reflexivity is a core aspect of agency, we argue that it operates to a backdrop of the routinization of social life and operates from within and not outside of habitus. We highlight the role of the breach in reflexivity, suggesting that it opens up a critical window for agents to initiate change. The article suggests caution in over-ascribing reflexivity to agency, instead arguing that achieving reflexivity and change is a difficult and fraught process, which has emotional and moral consequences. The effect of this is that people often prefer the status quo, rather than to risk change and uncertainty. © London School of Economics and Political Science 2015.

  12. Genetic variation in the parasympathetic signaling pathway in patients with reflex syncope

    DEFF Research Database (Denmark)

    Holmegard, H N; Benn, M; Mehlsen, J


    Reflex syncope is defined by a self-terminating transient loss of consciousness associated with an exaggerated response of the vagal reflexes upon orthostatic challenges. A hereditary component has previously been suggested. We hypothesized that variations in genes encoding proteins mediating...

  13. Reflexive awareness, transcendence and witnessing - in contemplative awareness cultures in school

    DEFF Research Database (Denmark)

    Nielsen, Anne Maj

    education in a Danish school. The contemplative activities in class have developed the children’s reflexive attitude. They described how contemplative exercises opened possibilities to become aware of their transient felt sensations, to reflexively direct their own awareness and change their state of being...... and to adopt an open and reflective self-perception and understanding of others....

  14. No evidence hip joint angle modulates intrinsically produced stretch reflex in human hopping. (United States)

    Gibson, W; Campbell, A; Allison, G


    Motor output in activities such as walking and hopping is suggested to be mediated neurally by purported stretch reflex augmentation of muscle output. Reflex EMG activity during these tasks has been frequently investigated in the soleus muscle; with alterations in reflex amplitude being associated with changes in hip joint angle/phase of the gait cycle. Previous work has focussed on reflex activity induced by an artificial perturbation or by induction of H-reflexes. As such, it is currently unknown if stretch reflex activity induced intrinsically (as part of the task) is modulated by changes in hip joint angle. This study investigated whether hip joint angle modulated reflex EMG 'burst' activity during a hopping task performed on a custom-built partially reclined sleigh. Ten subjects participated; EMG and kinematic data (VICON motor capture system) was collected for each hop cycle. Participants completed 5 sets of 30s of self-paced hopping in (1) hip neutral and (2) hip 60° flexion conditions. There was no difference in EMG 'burst' activity or in sagittal plane kinematics (knee/ankle) in the hopping task between the two conditions. The results indicate that during a functional task such as hopping, changes in hip angle do not alter the stretch reflex-like activity associated with landing. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Functionality of the contralateral biceps femoris reflex response during human walking

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend S.; Sinkjær, Thomas


    the treadmill velocity was altered concurrently or 50 ms after knee perturbation onset. These results, together with the finding that the cBF reflex response is under some cortical control [1], strongly suggest a functional role for the cBF reflex during walking that is adaptable to the environmental situation....

  16. Teaching Critical Reflexivity in Short-Term International Field Courses: Practices and Problems (United States)

    Glass, Michael R.


    This study critiques the use of critical reflexivity in short-term international field courses. Critical reflexivity's benefits include preparing students for professional research, deepening their learning, and giving the chance to see how student perspectives on fieldwork sites are influenced by their own identity and positionality. I use an…

  17. Collaborative Research in Contexts of Inequality: The Role of Social Reflexivity (United States)

    Leibowitz, Brenda; Bozalek, Vivienne; Farmer, Jean; Garraway, James; Herman, Nicoline; Jawitz, Jeff; McMillan, Wendy; Mistri, Gita; Ndebele, Clever; Nkonki, Vuyisile; Quinn, Lynn; van Schalkwyk, Susan; Vorster, Jo-Anne; Winberg, Chris


    This article reports on the role and value of social reflexivity in collaborative research in contexts of extreme inequality. Social reflexivity mediates the enablements and constraints generated by the internal and external contextual conditions impinging on the research collaboration. It fosters the ability of participants in a collaborative…

  18. Treating the Initial Physical Reflex of Misophonia With the Neural Repatterning Technique: A Counterconditioning Procedure

    Directory of Open Access Journals (Sweden)

    Thomas H. Dozier


    Full Text Available Misophonia is a condition in which a person has an acute emotional response of anger or disgust to a commonly occurring innocuous auditory or visual stimulus referred to as a trigger. This case details the effective treatment of misophonia in a young woman that included a counterconditioning treatment called the Neural Repatterning Technique (NRT, which combines a continuous positive stimulus and a reduced intensity, intermittent trigger. The treatment was delivered via the Misophonia Trigger Tamer smartphone app and all treatments were conducted independently by the patient. In this patient, the trigger elicited a physical reflex of contraction of the flexor digitorum profundus, which caused her to clench her fist. To enhance the effect of the NRT treatment, Progressive Muscle Relaxation was incorporated to increase her ability to deliberately relax the affected muscle during treatment. During NRT treatment sessions, the patient experienced a weak physical reflex to the reduced trigger stimulus but no emotional response. Her emotional response of misophonia was not treated, but when the physical reflex extinguished, the emotional response also extinguished. This case indicates that the misophonic response includes a Pavlovian-conditioned physical reflex. It is proposed that the trigger elicited the physical reflex and the physical reflex then elicited the conditioned emotional response that is characteristic of misophonia. Because of the conditioned reflex nature of misophonia, it is proposed that a more appropriate name for this disorder would be Conditioned Aversive Reflex Disorder.

  19. The visual rooting reflex in individuals with autism spectrum disorders and co-occurring intellectual disability

    NARCIS (Netherlands)

    de Bildt, Annelies; Mulder, Erik J.; Van Lang, Natasja D. J.; de With, S. A. Jytte; Minderaa, Ruud B.; Stahl, Sherin S.; Anderson, George M.

    The rooting reflex has long been studied by neurologists and developmentalists and is defined as an orientation toward tactile stimulation in the perioral region or visual stimulation near the face. Nearly, all previous reports of the visual rooting reflex (VRR) concern its presence in adults with

  20. Reflex sympathetic dystrophy in a child; Wspolczulna dystrofia odruchowa u dziecka

    Energy Technology Data Exchange (ETDEWEB)

    Napiontek, M.; Krasny, I. [Akademia Medyczna, Poznan (Poland)


    A case of reflex sympathetic dystrophy in 11 years old girl was described. The acute pain of the left food was preceded by loss of consciousness of unknown origin. Patchy osteopenia, very rare and non characteristic X-ray changes in children`s reflex sympathetic dystrophy, was observed, mimicking osteomyelitis, bone malignant tumor or Sudeck disease. (author). 5 refs, 2 figs.

  1. Reflex sympathetic dystrophy associated with squamous cell carcinoma of the lung. (United States)

    Prowse, M; Higgs, C M; Forrester-Wood, C; McHugh, N


    Reflex sympathetic dystrophy was the presenting feature in an otherwise occult case of non-metastatic squamous cell carcinoma of the lung which improved on surgical removal of the primary tumour. Reflex sympathetic dystrophy, therefore, should be considered an occasional manifestation of a paraneoplastic syndrome warranting a thorough search for underlying malignancy. Images PMID:2712617

  2. Thenar muscles H reflex in patients with fibromyalgia: A case control study

    Directory of Open Access Journals (Sweden)

    Kamran Azma


    Full Text Available Objective: To delineate H-reflex parameters and specify the diagnostic accuracy measures of thenar muscle H-reflex in Fibromyalgia (FM. Methods: The study was a cross sectional study performed on 30 subjects with FM and 30 healthy volunteers in two major referral hospitals. We recorded the number of obtainable thenar H-reflexes and their minimum latency, threshold and amplitude in each group. Results: There was a significantly more chance to elicit the H-reflex in patients with FM. H reflex threshold and minimum latency were lower in FM group but no significant difference was shown for H wave amplitude. According to our study, thenar H-reflex has 46.7% sensitivity, 86.7% specificity and 66.7% diagnostic accuracy to detect FM. It also has moderate predictive values and positive likelihood ratio but low negative likelihood ratio. Conclusion: Higher rate of thenar muscle H-reflex in fibromyalgia can be interpreted as a confirmatory finding to central sensitization theory for this disorder. Obtaining H-reflex from thenar muscles could be a helpful diagnostic tool for fibromyalgia that increases the confidence in diagnosis. Although it is a weak tool for screening because of low sensitivity, it has a relatively high specificity.

  3. Soleus H-reflex tests in causalgia-dystonia compared with dystonia and mimicked dystonic posture

    NARCIS (Netherlands)

    Koelman, J. H.; Hilgevoord, A. A.; Bour, L. J.; Speelman, J. D.; Ongerboer de Visser, B. W.


    Dystonia in the causalgia-dystonia syndrome is characterized by a fixed dystonic posture. To identify involvement of central pathophysiologic mechanisms, we analyzed soleus H-reflex tests in five patients with causalgia-dystonia. Soleus H-reflex test results in these patients differed from those in

  4. "Madam, Are You One of Them?" "Reflexivities of Discomfort" in Researching an "Illicit" Subject (United States)

    Namatende-Sakwa, Lydia


    Informed largely by Affect theory (2004), this paper takes up "reflexivities of discomfort" to reflexively engage with my affective struggles as a Christian, heterosexual, mother, educator, undertaking a study on homosexuality, which is a thorny issue in Uganda. It a methodological prologue, reflecting my thoughts and struggles before I…

  5. The Optokinetic Cervical Reflex (OKCR) in Pilots of High-Performance Aircraft. (United States)


    Instrument Metereological Conditions (See IFR) NVG - Night Vision Goggles OKCR - Optokinetic Cervical Reflex (also: Opto-Kinetic Cervico Reflex) SA...visual objects to fly and control the aircraft VMC - Visual Metereological Conditions (See VFR) 80 10. REFERENCES Crone, R.A. (1975). Optokinetically

  6. What is a reflex? A guide for understanding disorders of consciousness. (United States)

    Fischer, David B; Truog, Robert D


    Uncertainty in diagnosing disorders of consciousness, and specifically in determining whether consciousness has been lost or retained, poses challenging scientific and ethical questions. Recent neuroimaging-based tests for consciousness have cast doubt on the reliability of behavioral criteria in assessing states of consciousness and generate new questions about the assumptions used in formulating coherent diagnostic criteria. The reflex, a foundational diagnostic tool, offers unique insight into these disorders; behaviors produced by unconscious patients are thought to be purely reflexive, whereas those produced by conscious patients can be volitional. Further investigation, however, reveals that reflexes cannot be reliably distinguished from conscious behaviors on the basis of any generalizable empirical characteristics. Ambiguity between reflexive and conscious behaviors undermines the capacity of the reflex to distinguish between disorders of consciousness and has implications for how these disorders should be conceptualized in future diagnostic criteria. © 2015 American Academy of Neurology.

  7. Spatial control of reflexes, posture and movement in normal conditions and after neurological lesions

    Directory of Open Access Journals (Sweden)

    Feldman Anatol G.


    Full Text Available Control of reflexes is usually associated with central modulation of their sensitivity (gain or phase-dependent inhibition and facilitation of their influences on motoneurons (reflex gating. Accumulated empirical findings show that the gain modulation and reflex gating are secondary, emergent properties of central control of spatial thresholds at which reflexes become functional. In this way, the system pre-determines, in a feedforward and task-specific way, where, in a spatial domain or a frame of reference, muscles are allowed to work without directly prescribing EMG activity and forces. This control strategy is illustrated by considering reflex adaptation to repeated muscle stretches in healthy subjects, a process associated with implicit learning and generalization. It has also been shown that spasticity, rigidity, weakness and other neurological motor deficits may have a common source – limitations in the range of spatial threshold control elicited by neural lesions.

  8. Reflexive anaphor resolution in spoken language comprehension: structural constraints and beyond (United States)

    Clackson, Kaili; Heyer, Vera


    We report results from an eye-tracking during listening study examining English-speaking adults’ online processing of reflexive pronouns, and specifically whether the search for an antecedent is restricted to syntactically appropriate positions. Participants listened to a short story where the recipient of an object was introduced with a reflexive, and were asked to identify the object recipient as quickly as possible. This allowed for the recording of participants’ offline interpretation of the reflexive, response times, and eye movements on hearing the reflexive. Whilst our offline results show that the ultimate interpretation for reflexives was constrained by binding principles, the response time, and eye-movement data revealed that during processing participants were temporarily distracted by a structurally inappropriate competitor antecedent when this was prominent in the discourse. These results indicate that in addition to binding principles, online referential decisions are also affected by discourse-level information. PMID:25191290

  9. [Reflex sympathetic dystrophy involving the ankle in pregnancy: characteristics and therapeutic management]. (United States)

    Sergent, F; Mouroko, D; Sellam, R; Marpeau, L


    We report the case of a multigravida presenting in the first trimester of pregnancy with reflex sympathetic dystrophy involving both ankles. Preferential location of reflex sympathetic dystrophy in pregnancy is classically the hip (9 times out of 10). Symptoms develop mostly with primipara in the third trimester of pregnancy or in post-partum. Fracture is the major risk of reflex sympathetic dystrophy. Peculiarities of reflex sympathetic dystrophy's treatment in the course of pregnancy are evoked. The end of the pregnancy can be shortened with the aim of stabilizing disease even to activate its healing. Pathophysiologic mechanisms of reflex sympathetic dystrophy in pregnancy seem multiple and complex. Our observation, by its atypical characteristics, recalls it.

  10. An Intelligent Computerized Stretch Reflex Measurement System For Clinical And Investigative Neurology (United States)

    Flanagan, P. M.; Chutkow, J. G.; Riggs, M. T.; Cristiano, V. D.


    We describe the design of a reliable, user-friendly preprototype system for quantifying the tendon stretch reflexes in humans and large mammals. A hand-held, instrumented reflex gun, the impactor of which contains a single force sensor, interfaces with a computer. The resulting test system can deliver sequences of reproducible stimuli at graded intensities and adjustable durations to a muscle's tendon ("tendon taps"), measure the impacting force of each tap, and record the subsequent reflex muscle contraction from the same tendon -- all automatically. The parameters of the reflex muscle contraction include latency; mechanical threshold; and peak time, peak magnitude, and settling time. The results of clinical tests presented in this paper illustrate the system's potential usefulness in detecting neurologic dysfunction affecting the tendon stretch reflexes, in documenting the course of neurologic illnesses and their response to therapy, and in clinical and laboratory neurologic research.

  11. Stretch reflex improves rolling stability during hopping of a decerebrate biped system. (United States)

    Rosendo, Andre; Liu, Xiangxiao; Shimizu, Masahiro; Hosoda, Koh


    When humans hop, attitude recovery can be observed in both the sagittal and frontal planes. While it is agreed that the brain plays an important role in leg placement, the role of low-level feedback (the stretch reflex) on frontal plane stabilization remains unclear. Seeking to better understand the contribution of the soleus stretch reflex to rolling stability, we performed experiments on a biomimetic humanoid hopping robot. Various reflex responses to touching the floor, ranging from no response to long muscle activations, were examined, and the effect of a delay upon touching the floor was also examined. We found that the stretch reflex brought the system closer to stable, straight hopping. The presence of a delay did not affect the results; both the cases with and without a delay outperformed the case without a reflex response. The results of this study highlight the importance of low-level control in locomotion for which body stabilization does not require higher-level signals.

  12. Validation of the facial assessment by computer evaluation (FACE) program for software-aided eyelid measurements. (United States)

    Choi, Catherine J; Lefebvre, Daniel R; Yoon, Michael K


    The aim of this article is to validate the accuracy of Facial Assessment by Computer Evaluation (FACE) program in eyelid measurements. Sixteen subjects between the ages of 27 and 65 were included with IRB approval. Clinical measurements of upper eyelid margin reflex distance (MRD1) and inter-palpebral fissure (IPF) were obtained. Photographs were then taken with a digital single lens reflex camera with built-in pop-up flash (dSLR-pop) and a dSLR with lens-mounted ring flash (dSLR-ring) with the cameras upright, rotated 90, 180, and 270 degrees. The images were analyzed using both the FACE and ImageJ software to measure MRD1 and IPF.Thirty-two eyes of sixteen subjects were included. Comparison of clinical measurement of MRD1 and IPF with FACE measurements of photos in upright position showed no statistically significant differences for dSLR-pop (MRD1: p = 0.0912, IPF: p = 0.334) and for dSLR-ring (MRD1: p = 0.105, IPF: p = 0.538). One-to-one comparison of MRD1 and IPF measurements in four positions obtained with FACE versus ImageJ for dSLR-pop showed moderate to substantial agreement for MRD1 (intraclass correlation coefficient = 0.534 upright, 0.731 in 90 degree rotation, 0.627 in 180 degree rotation, 0.477 in 270 degree rotation) and substantial to excellent agreement in IPF (ICC = 0.740, 0.859, 0.849, 0.805). In photos taken with dSLR-ring, there was excellent agreement of all MRD1 (ICC = 0.916, 0.932, 0.845, 0.812) and IPF (ICC = 0.937, 0.938, 0.917, 0.888) values. The FACE program is a valid method for measuring margin reflex distance and inter-palpebral fissure.

  13. Two classes of spaces reflexive in the sense of Pontryagin

    International Nuclear Information System (INIS)

    Akbarov, S S; Shavgulidze, E T


    The Pontryagin-van Kampen duality for locally compact Abelian groups can be generalized in two ways to wider classes of topological Abelian groups: in the first approach the dual group X . is endowed with the topology of uniform convergence on compact subsets of X and in the second, with the topology of uniform convergence on totally bounded subsets of X. The corresponding two classes of groups 'reflexive in the sense of Pontryagin-van Kampen' are very wide and are so close to each other that it was unclear until recently whether they coincide or not. A series of counterexamples constructed in this paper shows that these classes do not coincide and also answer several other questions arising in this theory. The results of the paper can be interpreted as evidence that the second approach to the generalization of the Pontryagin duality is more natural

  14. Who's arguing? A call for reflexivity in bioethics. (United States)

    Ives, Jonathan; Dunn, Michael


    In this paper we set forth what we believe to be a relatively controversial argument, claiming that 'bioethics' needs to undergo a fundamental change in the way it is practised. This change, we argue, requires philosophical bioethicists to adopt reflexive practices when applying their analyses in public forums, acknowledging openly that bioethics is an embedded socio-cultural practice, shaped by the ever-changing intuitions of individual philosophers, which cannot be viewed as a detached intellectual endeavour. This said, we argue that in order to manage the personal, social and cultural embeddedness of bioethics, philosophical bioethicists should openly acknowledge how their practices are constructed and should, in their writing, explicitly deal with issues of bias and conflict of interest, just as empirical scientists are required to do.

  15. Some fixed point theorems in fuzzy reflexive Banach spaces

    International Nuclear Information System (INIS)

    Sadeqi, I.; Solaty kia, F.


    In this paper, we first show that there are some gaps in the fixed point theorems for fuzzy non-expansive mappings which are proved by Bag and Samanta, in [Bag T, Samanta SK. Fixed point theorems on fuzzy normed linear spaces. Inf Sci 2006;176:2910-31; Bag T, Samanta SK. Some fixed point theorems in fuzzy normed linear spaces. Inform Sci 2007;177(3):3271-89]. By introducing the notion of fuzzy and α- fuzzy reflexive Banach spaces, we obtain some results which help us to establish the correct version of fuzzy fixed point theorems. Second, by applying Theorem 3.3 of Sadeqi and Solati kia [Sadeqi I, Solati kia F. Fuzzy normed linear space and it's topological structure. Chaos, Solitons and Fractals, in press] which says that any fuzzy normed linear space is also a topological vector space, we show that all topological version of fixed point theorems do hold in fuzzy normed linear spaces.

  16. [Reflex dystrophy. Complex regional pain syndrome type I]. (United States)

    Petersen, Gry Kambskard; Jensen, Michael Reinhold; Dahlin, Lars B; Nielsen, Niels H Søe


    Reflex sympathetic dystrophy or complex regional pain syndrome type I is primarily a clinical diagnosis. The syndrome is most common after soft tissue damage or fractures and is more often seen in women than in men. The paramount symptom is pain, but oedema, a limited range of motion, changes in sensibility, and trophic changes are also seen. The pathogenesis is unknown, but most clinicians believe it to be caused by disturbances in the sympathetic or sensory nervous system and/or an excessive inflammatory response, most likely neurogenic inflammation. It seems that early treatment with physiotherapy and corticosteroids has a positive effect on the disease. Despite lack of documentation, the principles of treatment usually prescribed for the treatment of neurogenic pain must be taken into consideration. There is a lack of large double-blind studies on all aspects of the syndrome.

  17. Reflexively exploring knowledge and power in collaborative research

    DEFF Research Database (Denmark)

    Olesen, Birgitte Ravn; Pedersen, Chistina Hee; Frølunde, Lisbeth

    The proposed workshop will take its starting point in the challenges which collaborative research practices share. The aim of the workshop is to work with, and further develop, a range of critical, reflexive strategies for understanding, analysing and dealing with those challenges. The workshop...... will be designed in order to stimulate dialogue across different analytical perspectives and empirical research. The analytical perspectives on which facilitation will be based are rooted in social constructionist approaches to dialogic communication theory and action research. The challenges of collaborative...... knowledge forms, knowledge interests and wishes as to the research outcome. In official policy discourse and research practices, a positive picture is often painted of dialogue as a site for mutual learning on the basis of the different knowledge forms that the different participants bring with them...

  18. Normal sympathetic nervous system response in reflex sympathetic dystrophy. (United States)

    Figuerola, María de Lourdes; Levin, Gloria; Bertotti, Alicia; Ferreiro, Jorge; Barontini, Marta


    We evaluated sympathetic nervous system activity by sympathetic skin response (SSR) recording and we further investigated sympathetic and opioid outflow indirectly in patients with features of reflex sympathetic dystrophy by measuring concentrations of plasma catecholamines (CAs) and their metabolites and plasma metenkephalin (ME), before and after corticoid treatment. Six patients were studied. Basal SSR latencies, morphologies and amplitudes were normal in five patients. In one woman, latency and amplitude were also normal but the morphology was disturbed. Basal plasma ME, CA and metabolite levels were similar in the affected and non-affected limbs and a significant increase in plasma ME concentrations was observed in both affected and non-affected limbs after two weeks of steroid treatment. Altogether these results point to an adaptive supersensitivity rather than a sympathetic hyperactivity in this syndrome; also, they indicate that the therapeutic effect of steroids adds, to their known anti-inflammatory action, a stimulatory action on the endogenous opioid system.

  19. Another cause for conductive hearing loss with present acoustic reflexes. (United States)

    Ebert, Charles S; Zanation, Adam M; Buchman, Craig A


    There are numerous potential causes of conductive hearing loss (HL). It is important to obtain a thorough history and perform a complete examination, including audiometric testing and radiographic evaluation when necessary. In this report, we present a patient with an intact tympanic membrane, no history of ear disease or trauma who as an adult developed progressive, conductive HL because of an anomalous course of a dehiscent facial nerve. In the patient with a conductive HL and at least partially intact reflexes, superior semicircular canal dehiscence, fracture of the stapes superstructure proximal to the tendon, other third window phenomena, and now dehiscence of the facial nerve resulting in decreased mobility of the ossicular chain must be considered.

  20. Repetitive exposure: Brain and reflex measures of emotion and attention (United States)

    Ferrari, Vera; Bradley, Margaret M.; Codispoti, Maurizio; Lang, Peter J.


    Effects of massed repetition on the modulation of the late positive potential elicited during affective picture viewing were investigated in two experiments. Despite a difference in the number of repetitions across studies (from 5 to 30), results were quite similar: the late positive potential continued to be enhanced when viewing emotional, compared to neutral, pictures. On the other hand, massed repetition did prompt a reduction in the late positive potential that was most pronounced for emotional pictures. Startle probe P3 amplitude generally increased with repetition, suggesting diminished attention allocation to repeated pictures. The blink reflex, however, continued to be modulated by hedonic valence, despite massive massed repetition. Taken together, the data suggest that the amplitude of the late positive potential during picture viewing reflects both motivational significance and attention allocation. PMID:20701711

  1. Cholesteric Liquid Crystal Based Reflex Color Reflective Displays (United States)

    Khan, Asad


    Bistable color cholesteric liquid crystal displays are unique LCDs that exhibit high reflectivity, good contrast, extremely low power operation, and are amenable to versatile roll-to-roll manufacturing. The display technology, now branded as Reflex has been in commercialized products since 1996. It has been the subject of extensive research and development globally by a variety of parties in both academic and industrial settings. Today, the display technology is in volume production for applications such as dedicated eWriters (Boogie Board), full color electronic skins (eSkin), and displays for smart cards. The flexibility comes from polymerization induced phase separation using unique materials unparalleled in any other display technology. The blend of monomers, polymers, cross linkers, and other components along with nematic liquid crystals and chiral dopants is created and processed in such ways so as to enable highly efficient manufactrable displays using ultra thin plastic substrates -- often as thin as 50μm. Other significant aspects include full color by stacking or spatial separation, night vision capability, ultra high resolution, as well as active matrix capabilities. Of particular note is the stacking approach of Reflex based displays to show full color. This approach for reflective color displays is unique to this technology. Owing to high transparency in wavelength bands outside the selective reflection band, three primarily color layers can be stacked on top of each other and reflect without interfering with other layers. This highly surprising architecture enables the highest reflectivity of any other reflective electronic color display technology. The optics, architecture, electro-topics, and process techniques will be discussed. This presentation will focus on the physics of the core technology and color, it's evolution from rigid glass based displays to flexible displays, development of products from the paradigm shifting concepts to consumer

  2. Strain differences in baroceptor reflex in adult Wistar Kyoto rats

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti


    Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

  3. Reflex control of the spine and posture: a review of the literature from a chiropractic perspective

    Directory of Open Access Journals (Sweden)

    Schlappi Mark


    Full Text Available Abstract Objective This review details the anatomy and interactions of the postural and somatosensory reflexes. We attempt to identify the important role the nervous system plays in maintaining reflex control of the spine and posture. We also review, illustrate, and discuss how the human vertebral column develops, functions, and adapts to Earth's gravity in an upright position. We identify functional characteristics of the postural reflexes by reporting previous observations of subjects during periods of microgravity or weightlessness. Background Historically, chiropractic has centered around the concept that the nervous system controls and regulates all other bodily systems; and that disruption to normal nervous system function can contribute to a wide variety of common ailments. Surprisingly, the chiropractic literature has paid relatively little attention to the importance of neurological regulation of static upright human posture. With so much information available on how posture may affect health and function, we felt it important to review the neuroanatomical structures and pathways responsible for maintaining the spine and posture. Maintenance of static upright posture is regulated by the nervous system through the various postural reflexes. Hence, from a chiropractic standpoint, it is clinically beneficial to understand how the individual postural reflexes work, as it may explain some of the clinical presentations seen in chiropractic practice. Method We performed a manual search for available relevant textbooks, and a computer search of the MEDLINE, MANTIS, and Index to Chiropractic Literature databases from 1970 to present, using the following key words and phrases: "posture," "ocular," "vestibular," "cervical facet joint," "afferent," "vestibulocollic," "cervicocollic," "postural reflexes," "spaceflight," "microgravity," "weightlessness," "gravity," "posture," and "postural." Studies were selected if they specifically tested any or

  4. Binocular reflexes in the first 6 months of life: preliminary results of a study of normal infants. (United States)

    Coakes, R L; Clothier, C; Wilson, A


    The development of the binocular reflexes during the first 6 months of life was studied in 38 normal infants. Preliminary results indicate that the following reflex is well established by 2 months, convergence by 3 months and the corrective fusion reflex by the age of 5 months.

  5. Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans. (United States)

    Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K


    In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

  6. From Incidental, Mechanically-Induced Arrhythmias to Reflex-Defined Arrhythmogenicity: On The Track of The Ternary Reflex System Resemblance to The "Infancy" of New Era or Rediscovery. (United States)

    Stirbys, Petras


    The underlying pathophysiology of supraventricular and ventricular arrhythmias remains a matter of intense investigation. Though evolving, the contemporary explanations do not encompass all aspects of arrhythmogenicity. An improved understanding of arrhythmia substrate is needed to augment therapeutic capabilities. Our observation and literature sources demonstrate relatively high incidence of transitory arrhythmias which are non-intentionally generated by the endocardial lead/catheter manipulation. These findings are interesting and potentially may crystallize the reflex-dependent proarrhythmic cardiac activity. Herein we suggest the "reflexogenic arrhythmogenicity" concept extending an overall spectrum of known hypotheses. Cardiovascular reflex action can be categorized into three-tiered levels - intra-cellular, inter-cellular and inter-organic. The first two levels of the triplicate system reside within the cardiac anatomical landmarks (in fact intramurally, intra-organically), however the third one implicates central (cerebral) activity which boomerangs back via centripetal and centrifugal connections. These levels likely compose synoptic ternary reflex set system which may be validated in future studies. To hypothesize, coordinated mutual reciprocity of reflex activity results in stabilization of heart rhythm in robust heart. Any stressful cardiac event may lead to the shift of the rhythm toward unfavorable clinical entity probably via the loss of the influence of dominant reflex. Overall, an interaction and likely intrinsic inter-tiered competition along with possible interplay between physiological and pathological reflexes may be treated as contributing factors for the inception and maintaining of arrhythmias and cardiac performance as well. These assumptions await further documentation. If such a tenet were recognized, the changes in the clinical approach to arrhythmia management might be anticipated, preferably by selective reflex suppression or

  7. Monosynaptic Stretch Reflex Fails to Explain the Initial Postural Response to Sudden Lateral Perturbations. (United States)

    Mühlbeier, Andreas; Puta, Christian; Boström, Kim J; Wagner, Heiko


    Postural reflexes are essential for locomotion and postural stability, and may play an important role in the etiology of chronic back pain. It has recently been theoretically predicted, and with the help of unilateral perturbations of the trunk experimentally confirmed that the sensorimotor control must lower the reflex amplitude for increasing reflex delays to maintain spinal stability. The underlying neuromuscular mechanism for the compensation of postural perturbations, however, is not yet fully understood. In this study, we applied unilateral and bilateral sudden external perturbations to the trunk of healthy subjects and measured the muscular activity and the movement onset of the trunk. We found that the onset of the trunk muscle activity is prior to, or coincident with, the onset of the trunk movement. Additionally, the results of our experiments imply that the muscular response mechanism integrates distant sensory information from both sides of the body. These findings rule out a simple monosynaptic stretch reflex in favor of a more complex polysynaptic postural reflex mechanism to compensate postural perturbations. Moreover, the previously predicted negative correlation between reflex delay and reflex gain was also confirmed for bilateral perturbations.

  8. Monosynaptic Stretch Reflex Fails to Explain the Initial Postural Response to Sudden Lateral Perturbations

    Directory of Open Access Journals (Sweden)

    Andreas Mühlbeier


    Full Text Available Postural reflexes are essential for locomotion and postural stability, and may play an important role in the etiology of chronic back pain. It has recently been theoretically predicted, and with the help of unilateral perturbations of the trunk experimentally confirmed that the sensorimotor control must lower the reflex amplitude for increasing reflex delays to maintain spinal stability. The underlying neuromuscular mechanism for the compensation of postural perturbations, however, is not yet fully understood. In this study, we applied unilateral and bilateral sudden external perturbations to the trunk of healthy subjects and measured the muscular activity and the movement onset of the trunk. We found that the onset of the trunk muscle activity is prior to, or coincident with, the onset of the trunk movement. Additionally, the results of our experiments imply that the muscular response mechanism integrates distant sensory information from both sides of the body. These findings rule out a simple monosynaptic stretch reflex in favor of a more complex polysynaptic postural reflex mechanism to compensate postural perturbations. Moreover, the previously predicted negative correlation between reflex delay and reflex gain was also confirmed for bilateral perturbations.

  9. Analgesic-antiinflammatory drugs inhibit orbicularis oculi reflexes in humans via a central mode of action. (United States)

    Ferracuti, S; Leardi, M G; Cruccu, G; Fabbri, A; Itil, T M


    1. A cross-over single blind study examined the possible central effects of non-opioid analgesic drugs on the trigeminal reflexes. 2. The corneal reflex and blink reflex (R1, R2) were recorded electromyographically and response areas measured in healthy volunteers before and after intramuscular injection of piroxicam (40 mg); and after intravenous injection of lysine acetylsalicylate (500 mg). After the last drug recording the subjects received intravenous naloxone (2 mg) followed 5 minutes later by further reflex testing. Saline was used as a placebo in control experiments. 3. Both analgesics reduced the corneal reflex: piroxicam induced a 27% and lysine acetylsalicylate a 21% a reduction that naloxone did not reverse. Neither drug reduced the early or the late component of the blink reflex. 4. The marked inhibitory changes that the two non-narcotic analgesics produced on the corneal reflex--a nociceptive response--indicate a centrally-mediated action. 5. Naloxone's failure to reverse the induced analgesia argues against opiate receptor mediation.

  10. Emotional Dissonance and Burnout: The Moderating Role of Team Reflexivity and Re-Evaluation. (United States)

    Andela, Marie; Truchot, Didier


    The aim of the present study was to better understand the relationship between emotional dissonance and burnout by exploring the buffering effects of re-evaluation and team reflexivity. The study was conducted with a sample of 445 nurses and healthcare assistants from a general hospital. Team reflexivity was evaluated with the validation of the French version of the team reflexivity scale (Facchin, Tschan, Gurtner, Cohen, & Dupuis, 2006). Burnout was measured with the MBI General Survey (Schaufeli, Leiter, Maslach, & Jackson, 1996). Emotional dissonance and re-evaluation were measured with the scale developed by Andela, Truchot, & Borteyrou (2015). With reference to Rimé's theoretical model (2009), we suggested that both dimensions of team reflexivity (task and social reflexivity) respond to both psychological necessities induced by dissonance (cognitive clarification and socio-affective necessities). Firstly, results indicated that emotional dissonance was related to burnout. Secondly, regression analysis confirmed the buffering role of re-evaluation and social reflexivity on the emotional exhaustion of emotional dissonance. Overall, results contribute to the literature by highlighting the moderating effect of re-evaluation and team reflexivity in analysing the relationship between emotional dissonance and burnout. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems. (United States)

    Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David


    To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

  12. Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles. (United States)

    Masugi, Yohei; Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka


    While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg.

  13. Influence of delayed muscle reflexes on spinal stability: model-based predictions allow alternative interpretations of experimental data. (United States)

    Liebetrau, Anne; Puta, Christian; Anders, Christoph; de Lussanet, Marc H E; Wagner, Heiko


    Model-based calculations indicate that reflex delay and reflex gain are both important for spinal stability. Experimental results demonstrate that chronic low back pain is associated with delayed muscle reflex responses of trunk muscles. The aim of the present study was to analyze the influence of such time-delayed reflexes on the stability using a simple biomechanical model. Additionally, we compared the model-based predictions with experimental data from chronic low back pain patients and healthy controls using surface-electromyography. Linear stability methods were applied to the musculoskeletal model, which was extended with a time-delayed reflex model. Lateral external perturbations were simulated around equilibrium to investigate the effects of reflex delay and gain on the stability of the human lumbar spine. The model simulations predicted that increased reflex delays require a reduction of the reflex gain to avoid spinal instability. The experimental data support this dependence for the investigated abdominal muscles in chronic low back pain patients and healthy control subjects. Reflex time-delay and gain dependence showed that a delayed reflex latency could have relevant influence on spinal stability, if subjects do not adapt their reflex amplitudes. Based on the model and the experimental results, the relationship between muscle reflex response latency and the maximum of the reflex amplitude should be considered for evaluation of (patho) physiological data. We recommend that training procedures should focus on speeding up the delayed reflex response as well as on increasing the amplitude of these reflexes. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Chronological changes of blink reflex and MRI in a patient with lateral medullary infarction

    International Nuclear Information System (INIS)

    Kawamura, Hirotsune; Amano, Keiichi; Tanikawa, Tatsuya; Kawabatake, Hiroko; Kubo, Osami; Kitamura, Koichi; Ono, Yuko


    Recently, the brainstem pathways of bilateral late reflexes (R2) of electrically elicited blink reflex have been well established. An afferent delay or block of the late reflexes is closely related to a lesion of the lateral medullary portion. The chronological alteration of blink reflex (BR) was studied to compare with radiological abnormalities on MRI in a patient with lateral medullary infarction on the right side. A diagnosis of Wallenberg syndrome was made clinically and location of the lesion was identified in detail by MRI. The infarcted region which was well demonstrated as an increased intensity area on SE images obtained 52 days after the onset of symptoms was much smaller than that on SE as well as on IR image 21 days after the onset of symptoms. Therefore, it was concluded that more than half of the increased intensity area on the SE images obtained 21 days after the onset of symptoms recovered from the condition of being extremely damaged by ischemia on the right lateral medullary portion in this patient. On the other hand, in the initial BR 26 days after the onset of symptoms, the late reflexes (R2) were consistently absent bilaterally when the affected side (right) was stimulated and normal when the normal side (left) was stimulated. This type of BR abnormality is compatible with an afferent block of late reflexes (R2). The early reflex (R1) was normal on either side. Whereas in the second BR at 55 days after the onset of symptoms, the late reflexes turned to be normal in latency when the right side was stimulated. This recovery of late reflexes after the stimulation of the supraorbital nerve on the affected side was thought to be relevant to the part of disappearance of increased intensity area on the SE images obtained 52 days after the onset of symptoms. (J.P.N.)

  15. Circadian variation of flexor withdrawal and crossed extensor reflexes in patients with restless legs syndrome. (United States)

    Dafkin, Chloe; Green, Andrew; Olivier, Benita; Mckinon, Warrick; Kerr, Samantha


    An evening state of spinal hyperexcitability has been proposed to be a possible cause of evening increases in restless legs syndrome symptoms. Thus, the objective of the current study was to assess the circadian variation in spinal excitability in patients with restless legs syndrome based on flexor withdrawal reflex and crossed extensor reflex responses. The reflexes were elicited on 12 participants with restless legs syndrome and 12 healthy control participants in the evening (PM) and the morning (AM). Reflex response magnitudes were measured electromyographically and kinematically. Both the reflexes showed a circadian rhythm in participants with restless legs syndrome but not in control participants. Changes in ankle (median flexor withdrawal reflex PM: 16.0 ° versus AM: 2.8 °, P = 0.042; crossed extensor reflex PM: 0.8 ° versus AM: 0.2 °, P = 0.001) angle were significantly larger, and ankle angular velocity (median flexor withdrawal reflex PM: 38.8 ° s -1 versus AM: 13.9 ° s -1 , P = 0.049; crossed extensor reflex PM: 2.4 ° s -1 versus AM: 0.5 ° s -1 , P = 0.002) was significantly faster in the evening compared with the morning in participants with restless legs syndrome, for both reflexes. For participants with restless legs syndrome, evening change in hallux angle was significantly larger than morning responses (median PM: 5.0 ° versus AM: 1.3 °, P = 0.012). No significant differences for any of the electromyographic or kinematic variables were observed between participants with restless legs syndrome and controls. The flexor withdrawal reflex and the crossed extensor reflex show a circadian rhythm in participants with restless legs syndrome suggesting an evening increase in spinal excitability. We hypothesize the circadian variation in spinal excitability may be due to a possible nocturnal form of afferent circuitry central sensitization in the dorsal horn of the spinal cord in patients with restless legs syndrome. © 2017

  16. Research progress of the relationship between abnormal vestibular reflexes and adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Lin Yang


    Full Text Available Adolescent idiopathic scoliosis (AIS is an agnogenic structural scoliosis occurring in adolescence, and the main diagnostic criteria is coronal Cobb angle >10°in total spine X-ray. Studies have shown that AIS may be associated with abnormal postural reflexes, vestibular system is an important component of postural reflexes and its mechanism in the occurrence and development of scoliosis has received wide attention in recent years. In the study, the research progress on the role of abnormal vestibular reflexes in the pathogenesis of AIS was mainly introduced to help the clinicians better understand the pathogenesis of AIS and provide new ideas for AIS study.

  17. A task dependent change in the medium latency component of the soleus stretch reflex

    DEFF Research Database (Denmark)

    Grey, Michael James; Larsen, Birgit; Sinkjær, Thomas


    In comparison to the H-reflex, the task dependency of the human stretch reflex during locomotive and postural tasks has not received a great deal of attention in the literature. The few studies on reflex task dependency that have been performed to date have concentrated on either the group Ia...... with a portable stretching device. Perturbations of equal amplitude and velocity (8 deg, 300 deg/s) were presented to 16 healthy subjects while they walked on a treadmill and pedalled a cycle ergometer. For eight of these subjects, an additional set of data was collected as they sat on the ergometer holding...

  18. Particular features of conditioned electrodefensive reflex in white rats on background of constant magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Shust, I.V.; Galantyuk, S.I.; Cheretyanko, Yu.V.

    Study of the influence of magnetic fields upon the higher nervous activity of man and animals has long been attracting the attention of researchers. It is indicated in the literature that magnetic fields inhibit development of conditioned reflexes in planarians, fishes, and mammals. However, there are data of opposite nature as well, indicating accelerated development of the avoidance reflex in animals exposed previously to a magnetic field. Researchers studied formation of a conditioned electrodefensive reflex (CER) in white rats exposed to a constant magnetic field (CMF), and the influence of a vitamin preparation - galascorbin - on formation of the CER in animals exposed to a CMF.

  19. High-power ion beam generation with an inverse reflex tetrode

    International Nuclear Information System (INIS)

    Pasour, J.A.; Mahaffey, R.A.; Golden, J.; Kapetanakos, C.A.


    A new reflexing-electron ion source is described. The device produces a unidirectional ion beam with relatively high efficiency even when the applied magnetic field exceeds the self-field. This new source operates at a low, constant impedance during much of the applied voltage pulse and is better matched to available high-power, low-impedance generators than previous reflexing-electron devices. Proton pulses with peak current approx.500 kA have been produced with the inverse reflex tetrode coupled to the Gamble II generator


    Directory of Open Access Journals (Sweden)



    Full Text Available Risk phenomena in the Silvania Mountains, intuitive and genetic reflexes. In the contemporary period, the scientific research under the auspices of the global development has experienced a real quantitative and qualitative revolution. Theoretically and methodologically, the widespread promotion of the “concept of discontinuity” in terms of content, significances, manifestation, implications is observed, which has become a new imperative of the nowadays geography. The phenomena of discontinuity happen as real “paroxysmal, rhythm and intensity ruptures“ in relation to the normal occurrence defined either through the average value, determined on statistical basis as hydrological, meteorological, climatic phenomena or in discrete forms, when the phenomena occur in a veiled manner and they are perceptible only through their effects, respectively the environmental reflexes. Among the notions used with reference to extreme evolutionary discontinuities, we quote: the hazard, the disaster, the calamity and the risk to which was added a series of related notions: stability, sensitivity, resilience, fragility and vulnerability. The Silvania Mountains, a representative territorial unit within Silvania Land, with a fascinating and controversial geological origin, a real petrographic synthesis with uncovered crystalline stone, brought to the surface due to erosion under the layers of Neogene sediments, as a last remaining of a grandiose Hercynian chain with a varied orientation SW-NE of which were part the Massif Central –France, the east side, the Vosges Mountains, the Black Forest Mountains, the Harz Mountains and Bohemia. In this range of mountains, we also mention the Silvania Hercynian Mountains, respectively Plopiș and Meseș Mountains.This mountainous elevation level has an important role within the landscape as "geographical discontinuity factor” on one hand, between the Someșan Plateau and the Silvania piedmontan hills (Meseș Mountains

  1. Reflexivity in midwifery research: the insider/outsider debate. (United States)

    Burns, Elaine; Fenwick, Jennifer; Schmied, Virginia; Sheehan, Athena


    To explore the challenges of conducting an observational study of postnatal interactions, between midwives and women, when the researcher was a midwife observing in familiar midwifery settings. Participant observation conducted by researchers who are themselves midwives raises questions regarding the influence of 'identity' and 'insider' knowledge on the conduct of such projects. The insider/outsider status of researchers has been explored in other disciplines, yet this is an area which is underdeveloped in the midwifery literature where few attempts have been made to subject this issue to sustained analysis. A qualitative study (investigating the provision of breast-feeding support in the first week after birth) provided the opportunity for reflexive exploration of the tensions faced by midwife researchers. Two maternity units in New South Wales, Australia. Participants included 40 midwives and 78 breast-feeding women. Possessing 'insider' midwifery knowledge was advantageous in the 'getting in' and 'fitting in' phases of this research study however unanticipated role ambiguity, and moral and ethical challenges, arose as a result of this 'insider' knowledge and status. Prolonged periods of observation challenged the midwife researcher's preconceived ideas and early decisions about the advantages and disadvantages of being an 'insider' or an 'outsider' in the research setting. Reflexive analysis of insider/outsider experiences revealed the middle ground which participant observers tend to navigate. Whilst professional insider knowledge and status offered many advantages, especially at the first study setting, some of the inherent embodied, and socially constructed features of the 'midwife' observer role, were unanticipated. Cultural competence, in these observational study settings, translated into role ambiguity, and at times, culturally entrenched role expectations. Midwifery observation of clinical practice, for research, or practice development purposes

  2. Palateless custom bar supported overdenture: A treatment modality to treat patient with severe gag reflex

    Directory of Open Access Journals (Sweden)

    Kunwarjeet Singh


    Conclusion: Palateless custom bar supported overdenture procedure can be successfully used for the management of patients with severe gag reflex with improved denture retention, stability, chewing efficiency and comfort of the patient.

  3. Increased whole-body auditory startle reflex and autonomic reactivity in children with anxiety disorders

    NARCIS (Netherlands)

    Bakker, Mirte J; Tijssen, Marina A J; van der Meer, Johan N; Koelman, Johannes H T M; Boer, Frits

    Background: Young patients with anxiety disorders are thought to have a hypersensitive fear system, including alterations of the early sensorimotor processing of threatening information. However, there is equivocal support in auditory blink response studies for an enlarged auditory startle reflex

  4. Increased whole-body auditory startle reflex and autonomic reactivity in children with anxiety disorders

    NARCIS (Netherlands)

    Bakker, Mirte J.; Tijssen, Marina A. J.; van der Meer, Johan N.; Koelman, Johannes H. T. M.; Boer, Frits


    Background: Young patients with anxiety disorders are thought to have a hypersensitive fear system, including alterations of the early sensorimotor processing of threatening information. However, there is equivocal support in auditory blink response studies for an enlarged auditory startle reflex

  5. Influence of posture and muscle length on stretch reflex activity in poststroke patients with spasticity

    NARCIS (Netherlands)

    Fleuren, J.F.M.; Fleuren, Judith F.; Nederhand, Marcus Johannes; Hermens, Hermanus J.

    Objective To investigate the influence of different positions on stretch reflex activity of knee flexors and extensors measured by electromyography in poststroke patients with spasticity and its expression in the Ashworth Scale.

  6. How Can Hypnodontics Manage Severe Gag Reflex for Root Canal Therapy? A Case Report (United States)

    Ramazani, Mohsen; zarenejad, Nafiseh; Parirokh, Masoud; Zahedpasha, Samir


    In endodontics, severe involuntary gagging can have a severe impact on treatment procedure. There are many ways to ease the gag reflex, one of which is hypnosis. A 34-year-old male was referred for root canal treatment of a molar tooth. He had not received any dental treatments for the past nine years due to fear of severe gag reflex. Three hypnotic sessions based upon eye fixation, progressive muscle relaxation and guided imagery techniques were spent for psychosomatic management. The gag reflex was controlled and reduced to a normal level, and the required dental treatments including root canal therapy and restoration were performed successfully. This report shows that hypnosis can control gag reflex for dental treatments. PMID:27141226

  7. Identification of a Hammerstein Model of the Stretch Reflex EMG using Cubic Splines

    National Research Council Canada - National Science Library

    Dempsey, Erika


    .... The identification algorithm based on a separable least squares Levenberg-Marquardt optimization is used to identify a Hammerstein model of the stretch reflex EMG recorded from a spinal cord injured patient...

  8. Central sensitization in spinal cord injured humans assessed by reflex receptive fields

    DEFF Research Database (Denmark)

    Biurrun Manresa, José Alberto; Finnerup, Nanna Susanne Brix; Johannesen, Inger Lauge


    OBJECTIVE: To investigate the effects of central sensitization, elicited by intramuscular injection of capsaicin, by comparing the reflex receptive fields (RRF) of spinally-intact volunteers and spinal cord injured volunteers that present presensitized spinal nociceptive mechanisms. METHODS: Fift...

  9. Gaze stabilization reflexes in the mouse: New tools to study vision and sensorimotor

    NARCIS (Netherlands)

    B. van Alphen (Bart)


    markdownabstract__abstract__ Gaze stabilization reflexes are a popular model system in neuroscience for connecting neurophysiology and behavior as well as studying the neural correlates of behavioral plasticity. These compensatory eye movements are one of the simplest motor behaviors,

  10. Factitious lymphoedema as a psychiatric condition mimicking reflex sympathetic dystrophy: a case report. (United States)

    Nwaejike, Nnamdi; Archbold, Hap; Wilson, Darrin S


    Reflex sympathetic dystrophy can result in severe disability with only one in five patients able to fully resume prior activities. Therefore, it is important to diagnose this condition early and begin appropriate treatment. Factitious lymphoedema can mimic reflex sympathetic dystrophy and is caused by self-inflicted tourniquets, blows to the arm or repeated skin irritation. Patients with factitious lymphoedema have an underlying psychiatric disorder but usually present to emergency or orthopaedics departments. Factitious lymphoedema can then be misdiagnosed as reflex sympathetic dystrophy. The treatment for factitious lymphoedema is dealing with the underlying psychiatric condition. We share our experience of treating a 33-year-old man, who presented with factitious lymphoedema, initially diagnosed as reflex sympathetic dystrophy. Awareness of this very similar differential diagnosis allows early appropriate treatment to be administered.

  11. The tripartite origins of the tonic neck reflex: Gesell, Gerstmann, and Magnus. (United States)

    Shevell, Michael


    The standard neurologic examination of the newborn and infant includes the elicitation of the tonic neck reflex. Normally present, its persistence is suggestive of neurologic dysfunction and a prognostic marker highly suggestive of an adverse outcome. Working in different fields, with different approaches and largely independently, three leaders of early 20th century neurosciences (Rudolf Magnus, Josef Gerstmann, and Arnold Gesell) elaborated different aspects of this primitive reflex. Magnus provided the first description in an animal model utilizing a meticulously prepared decerebrate cat correctly identifying the reflex's reliance on proprioceptors in the neck and processing in the upper cervical segment. Gerstmann first described its occurrence in the setting of neurologic disease, providing a meticulous written description in an early description of the index case of what would later be eponymously designated Gerstmann-Straussler-Scheinker syndrome. Gesell initially described the reflex's fundamental occurrence in normal young infants, highlighting its adaptive role in early development and its persistence as a hallmark of neurologic pathology.

  12. Factitious lymphoedema as a psychiatric condition mimicking reflex sympathetic dystrophy: a case report

    Directory of Open Access Journals (Sweden)

    Nwaejike Nnamdi


    Full Text Available Abstract Introduction Reflex sympathetic dystrophy can result in severe disability with only one in five patients able to fully resume prior activities. Therefore, it is important to diagnose this condition early and begin appropriate treatment. Factitious lymphoedema can mimic reflex sympathetic dystrophy and is caused by self-inflicted tourniquets, blows to the arm or repeated skin irritation. Patients with factitious lymphoedema have an underlying psychiatric disorder but usually present to emergency or orthopaedics departments. Factitious lymphoedema can then be misdiagnosed as reflex sympathetic dystrophy. The treatment for factitious lymphoedema is dealing with the underlying psychiatric condition. Case presentation We share our experience of treating a 33-year-old man, who presented with factitious lymphoedema, initially diagnosed as reflex sympathetic dystrophy. Conclusion Awareness of this very similar differential diagnosis allows early appropriate treatment to be administered.

  13. Oculocardiac reflex elicited by orbital floor fracture and inferior globe displacement

    Directory of Open Access Journals (Sweden)

    Chau M. Pham


    Conclusions and importance: The oculocardiac reflex can precipitate marked bradycardia and hypotension in the setting of trauma with significant orbital and maxillofacial injury. Prompt identification and management with vagolytic agents or definitive surgical intervention may prevent morbidity or mortality.

  14. Management of exaggerated gag reflex in dental patients using intravenous sedation with dexmedetomidine

    Directory of Open Access Journals (Sweden)

    Aleksei P Reshetnikov


    Full Text Available Pharmacological sedation is one of the effective ways of prevention of gag reflex development in patients experiencing anxiety and fright before dental treatment. We are reporting a case where we could successfully eliminate exaggerated gag reflex (intravenous [IV] Gagging Severity Index in a dental patient using IV sedation with dexmedetomidine. IV administration of dexmedetomidine provided elimination of gag reflex at a depth of sedation for the patient with the Richmond Agitation-Sedation Scale score of −2 and −1. The patient received dexmedetomidine 1.0 μg/kg for 10 min and then a continuous infusion of dexmedetomidine 0.4 μg/kg/h. The use of dexmedetomidine for sedation may be an alternative to other pharmacological agents in patients with dental anxiety accompanied by exaggerated gag reflex.

  15. The usefulness and feasibility of a reflexivity method to improve clinical handover

    NARCIS (Netherlands)

    Broekhuis, Manda; Veldkamp, Carla

    Objective The evaluation of the usefulness and feasibility of the reflexivity method (RM), which encourages dialogue and reflections between doctors, and enables change. Methods On the basis of literature research into effective medical professional learning and reflection, essential elements that

  16. Pharmacological Isolation of Cognitive Components Influencing the Pupillary Light Reflex

    Directory of Open Access Journals (Sweden)

    Stuart R. Steinhauer


    Full Text Available Cognitive operations can be detected by reduction of the pupillary light response. Neurophysiological pathways mediating this reduction have not been distinguished. We utilized selective blockade of pupillary sphincter or dilator muscles to isolate parasympathetic or sympathetic activity during cognition, without modifying central processes. Pupil diameter was measured during the light reaction in 29 normal adults under three processing levels: No Task, during an easy task (Add 1, or a difficult task (Subtract 7. At three separate sessions, the pupil was treated with placebo, tropicamide (blocking the muscarinic sphincter receptor, or dapiprazole (blocking the adrenergic dilator receptor. With placebo, pupil diameter increased with increasing task difficulty. The light reaction was reduced only in the Subtract 7 condition. Dapiprazole (which decreased overall diameter showed similar task-related changes in diameter and light reflex as for placebo. Following tropicamide (which increased overall diameter, there was a further increase in diameter only in the difficult task. Findings suggest two separate inhibitory components at the parasympathetic oculomotor center. Changes in baseline diameter are likely related to reticular activation. Inhibition of the light reaction in the difficult task is likely associated with cortical afferents. Sustained sympathetic activity also was present during the difficult task.

  17. Visceral orienting reflexes as significant components of psychophysiologic personality assessment. (United States)

    Corson, S A; Corson, E O


    Activ. nerv. sup. (Praha) 28, 2, 1986. Utilizing a combination of idiographic and nomothetic research designs with repeated measures in several breeds of dogs, we discovered stable constitutional differences in psychophysiologic reactions to repeated exposure to psychologically stressful situations. Some dogs showed high psychophysiologic adaptation (HA dogs). Other dogs developed persistent psychophysiologic reactions to the psychologically aversive environment: tachycardia, polypnea, profuse salivation, high energy metabolism and muscle tension, and high urinary vasopressin and catecholamines (low adaptation or LA dogs). Retrospective analysis of the development and extinction of cardiac and respiratory orienting reflexes (OR) in these two types of dogs revealed that the LA dogs exhibit higher frequency and more intense, persistent and highly fluctuating (poorly modulated) cardiac and respiratory OR than the HA dogs, which show rapid OR habituation and good modulation. Insofar as one may extrapolate these data to human subjects, recording dynamics of development and habituation and degree of modulation of visceral OR may facilitate early detection of individuals at risk for cardiorespiratory and other psychovisceral disorders.

  18. Algumas reflexões sobre a autobiografia de Louis Althusser

    Directory of Open Access Journals (Sweden)

    Marta Rezende Cardoso

    Full Text Available L’avenir dure longtemps (O futuro dura muito tempo, relato autobiográfico de Louis Althusser, é um texto de grande riqueza, e que se presta à investigação psicanalítica. Neste artigo, nossa leitura foi orientada por uma reflexão sobre o tema do superego. Explorando a história de Althusser, observamos um conflito interminável: ser subjugado, internamente, pela sexualidade inconsciente do outro. Analisamos o aspecto traumático e violento desta “relação de poder” – poder sexual – mostrando como esta se exerce na economia psíquica, aí delineando, a nível das instâncias psíquicas, uma configuração particular. Mediante este material, desenvolvemos a idéia de que a instância do superego é ancorada no pulsional, e que impõe no psiquismo um modo de “legalidade interna” implacável e contraditória na qual o indivíduo pode, de certa forma, permanecer prisioneiro.

  19. Reliability of the Spinal Cord Assessment Tool for Spastic Reflexes. (United States)

    Akpinar, Pinar; Atici, Arzu; Ozkan, Feyza U; Aktas, Ilknur; Kulcu, Duygu G; Kurt, Kubra Neslihan


    To assess the reliability of the Spinal Cord Assessment Tool for Spastic Reflexes (SCATS). Observational reliability study of the SCATS. Inpatient rehabilitation unit at an education and research hospital. Subjects (N=47) between the ages of 18 and 88 years with spinal cord injury (SCI) and with American Spinal Injury Association Impairment Scale grades from A to D with spasticity, who were at least 6 months postinjury. Not applicable. Interrater and test-retest reliability of the SCATS. The SCATS had substantial to almost perfect interrater agreement (κ=.669-1.000) between the 2 physiatrists. Test-retest agreement of the SCATS was also substantial to almost perfect (κ=.614-1.000) as well. There was a significant correlation between the SCATS clonus scores and the Modified Ashworth scores of the hip, knee, and ankle. No correlation was found between SCATS extensor spasm scores and Modified Ashworth scores. The SCATS flexor spasm scores were only correlated significantly with the ankle plantar flexor Modified Ashworth scores (P<.05). The SCATS is a reliable tool for assessing spasm activity and spastic hypertonia in patients with SCI. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Critical reflexivity in financial markets: a Hawkes process analysis (United States)

    Hardiman, Stephen J.; Bercot, Nicolas; Bouchaud, Jean-Philippe


    We model the arrival of mid-price changes in the E-mini S&P futures contract as a self-exciting Hawkes process. Using several estimation methods, we find that the Hawkes kernel is power-law with a decay exponent close to -1.15 at short times, less than ≈ 103 s, and crosses over to a second power-law regime with a larger decay exponent ≈-1.45 for longer times scales in the range [ 103,106 ] seconds. More importantly, we find that the Hawkes kernel integrates to unity independently of the analysed period, from 1998 to 2011. This suggests that markets are and have always been close to criticality, challenging a recent study which indicates that reflexivity (endogeneity) has increased in recent years as a result of increased automation of trading. However, we note that the scale over which market events are correlated has decreased steadily over time with the emergence of higher frequency trading.

  1. Evolution and facial action in reflex, social motive, and paralanguage. (United States)

    Fridlund, A J


    Based upon current evolutionary theory and recent laboratory and field data, this paper introduces a behavioral-ecology view of human facial displays that contrasts with previous views of faces as innate, prototypic, "iconic" expressions of fundamental emotions. First, I detail the criteria for establishing genetic and epigenetic contributions to facial behavior. Under these criteria, cross-cultural communality in canonical facial displays implies neither their genetic control nor their fundamental relation to emotion. New findings reestablish phylogenetic continuity by showing that human facial displays and vigilance for them, like their nonhuman counterparts, coevolve in the service of social motives; faces issued in solitude typically reflect imaginary or implicit interaction. Two evolutionary trends are probably involved in shaping facial actions--emancipation of reflexes, and automatization of instrumental acts. Modern conceptions of genetic and cultural evolution, and knowledge about animal signaling, suggest new hypotheses regarding the origins and functions of facial displays. In so doing, they clarify how facial displays relate to reflexion, motive and intention, emotion and psychophysiology, and language and paralanguage.

  2. Uma Reflexão sobre Autoria Acadêmica

    Directory of Open Access Journals (Sweden)

    Francisco José da Costa


    Full Text Available Este estudo tem como objetivo apresentar elementos para um debate sobre a ética das práticas de autoria no campo científico brasileiro. Os autores utilizam exemplos ilustrativos para explorar as práticas de pseudoautoria, estabelecendo relações entre essas práticas, as coerções oriundas do campo acadêmico e o habitus dos agentes sociais. Foi elaborada uma definição preliminar do que seja autoria a fim de possibilitar a discussão sobre dois problemas centrais, que são: a lógica de “colocar o nome” e o plágio. Uma das principais contribuições deste trabalho repousa na reflexão orientada para a construção de uma prática aperfeiçoada de autoria, possibilitando a crítica e a autocrítica dos agentes do meio acadêmico sobre algumas práticas problemáticas de autoria.

  3. Games on Games. Game Design as Critical Reflexive Practice

    Directory of Open Access Journals (Sweden)

    Giovanni Caruso


    Full Text Available Can video game design be compared to more formalized practices of scientific research or speculation within game studies? And, by virtue of an intellectual leap that in itself calls for discussion, can video games be considered as an efficient vehicle for the presentation of certain kinds of knowledge, in the same way in which papers, conference presentations, and books are? What Ratto defines as critical making (2011, the practice of producing artifacts of different sorts in order to supplement and extend critical reflection, may apply to video games as well. Forms of research through design (Zimmerman, Forlizzi and Evenson, 2007, of carpentry (Bogost, 2012, and speculative design (Dunne and Raby, 2013 have been analyzed, discussed, and maybe most importantly, put into practice in different fields of cultural and scientific production. To address this gap and to map the current (and future state of self-reflexive games, we asked both researchers and designers to imagine an application of these concepts to video games. Paraphrasing Zimmerman, Forlizzi and Evenson, what does research through game design might mean? What epistemological insights can we derive from the act of designing, making and playing video games?

  4. [Complex regional pain syndrome. Reflex sympathetic dystrophy and causalgia]. (United States)

    Baron, R; Binder, A; Ulrich, W; Maier, C


    Complex regional pain syndromes (CRPS) occur as the inadequate response to painful trauma in a distal extremity. With CRPS I (sympathetic reflex dystrophy), no lesion of the nerve is present. Aside from sensory disturbances, burning deep spontaneous pain and mechanical allodynia are characteristic. Disturbances in the skin blood circulation, sweating, edema, and trophic disturbances of the skin, joints, and bones are typical. Reduction in muscle strength, tremor, and late dystonic changes comprise the motor disturbances. All symptoms are distributed in the distal extremity and not limited to the region of the peripheral nerves. Complex regional pain syndrome II (causalgia), develops following a partial peripheral nerve lesion. The distally generalized symptoms are identical. Successful therapy depends on an early start of interdisciplinary treatment. In addition to the pain therapy, physiotherapy plays a decisive role in rehabilitation. During the acute phase, freedom from pain at rest and retrogression of the edema must be achieved. With slight spontaneous pain, a conservative therapeutic method may be applied (analgesics, rest, raised position). In case of insufficient improvement and in difficult cases, the effect of intervention (sympathetic blockade) should be tested and possibly a blockade series performed. After reduced spontaneous pain, physiotherapy should be increased stepwise.

  5. Reflex sympathetic dystrophy: a retrospective epidemiological study of 168 patients. (United States)

    Duman, Iltekin; Dincer, Umit; Taskaynatan, Mehmet Ali; Cakar, Engin; Tugcu, Ilknur; Dincer, Kemal


    This is a retrospective epidemiological study. The objective is to determine the epidemiological characteristics including the patient demographics, etiological factors, duration of symptoms, treatment modalities applied and clinical outcome of the treatment in reflex sympathetic dystrophy (RSD). Medical records of the 168 patients managed in two tertiary hospitals with the diagnosis of RSD that was made according to both IASP criteria and three-phase bone scan were reviewed. The upper limb was affected 1.5 times as commonly as the lower limb. Of the 168 cases, 10.7% were non-traumatic. In 89.3% of the patients, RSD developed after a traumatic inciting event with a predominance of fracture. In 75.6% of the patients, RSD developed due to job-related injuries. The percentage of successful clinical outcome was 72%. The percentage of the patients that did not respond to therapy was 28%. The management period is long and this causes higher therapeutic costs in addition to loss of productive effort. However, response to therapy is good. On the other hand, in approximately one third of the patients, RSD does not improve despite all therapeutic interventions. In addition to compensation costs, this potentially debilitating feature causes RSD to appear as a socioeconomic problem.

  6. Acceptance of the different denominations for reflex sympathetic dystrophy (United States)

    Alvarez-Lario, B; Aretxabala-Alciba..., I; Alegre-Lopez, J; Alonso-Valdiviels..., J


    OBJECTIVE—To elucidate the real impact in the medical literature of the different denominations for reflex sympathetic dystrophy (RSD).
METHODS—A search was performed through the Medline database (WinSPIRS, SilverPlatter International, NS), from 1995 to 1999, including the following descriptors: RSD, complex regional pain syndrome (CRPS), CRPS type I, algodystrophy, Sudeck, shoulder-hand syndrome, transient osteoporosis, causalgia, and CRPS type II.
RESULTS—The descriptor RSD was detected in 576 references, algodystrophy in 54, transient osteoporosis in 42, CRPS type I in 24, Sudeck in 16, and shoulder-hand syndrome in 11. One hundred records were obtained for the descriptor causalgia and five for CRPS type II. The descriptor RSD was detected in the title of 262 references, algodystrophy in 29, transient osteoporosis in 29, CRPS type I in 15, Sudeck in 3, shoulder-hand syndrome in 5, causalgia in 17, and CRPS type II in 3 references.
CONCLUSIONS—The new CRPS terminology has not effectively replaced the old one. RSD and causalgia are the most used denominations.


  7. Reflex sympathetic dystrophy--a complex regional pain syndrome. (United States)

    Turner-Stokes, L


    Reflex sympathetic dystrophy (RSD) is a complex and poorly-understood condition characterized by: (a) pain and altered sensation; (b) motor disturbance and soft tissue change; (c) vasomotor and autonomic changes; and (d) psychosocial disturbance. Neurological symptoms typically do not conform to any particular pattern of nerve damage. Many different names have been ascribed to this condition and most recently the term 'complex regional pain syndrome' has been coined to emphasize the complex interaction of somatic, psychological and behavioural factors. Diagnostic criteria have been proposed by the International Association for the Study of Pain, but are still subject to debate. This review article describes the clinical features which may present as part of the condition, and the patho-physiology and pre-disposing factors so far identified. The evidence for effectiveness of different interventions is presented and a treatment approach outlined for inter-disciplinary management. While RSD is traditionally associated with pain in the extremities, the possibility is raised that the same process may underlie chronic pain syndromes affecting more central structures, such as testicular or pelvic pain.

  8. [Reflex sympathetic dystrophy secondary to piriformis syndrome: a case report]. (United States)

    Akçali, Didem; Taş, Ayça; Cizmeci, Pelin; Oktar, Suna; Zinnuroğlu, Murat; Arslan, Emre; Köseoğlu, Hüseyin; Babacan, Avni


    Piriformis syndrome is a rare cause of hip and foot pain which may be due to sciatic nerve irritation because of anatomic abnormalities of sciatic nerve and piriformis muscle or herniated disc, facet syndrome, trochanteric bursit, sacroiliac joint dysfunction, endometriosis and other conditions where sciatic nerve is irritated. There has been no reflex sympathetic dystrophy (RSD) case presented due to piriformis syndrome before. A sixty-two-year-old female patient had right foot and hip pain (VNS: 8), redness and swelling in the foot since 15 days. Her history revealed long walks and travelling 3 weeks ago and sitting on the foot for a long time for a couple of days. Physical examination revealed painful hip movement, positive straight leg rise. Erythema and hyperalgesia was present in dorsum of the right foot. Right foot dorsiflexion was weak and hyperesthesia was found in right L4-5 dermatome. Medical treatment and ultrasound treatment to piriformis muscle was not effective. The patient was injected 40 mg triamcinolon and local anesthetic in right piriformis muscle under floroscopy by diagnosis of piriformis syndrome, neuropathic pain and RSD. Pain and hyperalgesia resolved and motor weakness was better. During follow-up right foot redness resolved and pain decreased (VNS: 1). In this case report, there was vascular, muscle and skeletal signs supporting RSD, which shows us the therapoetic effect of diagnostic piriformis injection. The patient history, physical examination and diagnostic tests were evaluated by a multidisciplinary team which contributed to the treatment.

  9. [Reflex sympathetic dystrophy: still a poorly defined entity]. (United States)

    Ornetti, Paul; Maillefert, Jean-Francis


    The reflex sympathetic dystrophy (algodystrophy) constitutes a large nosological field of which the main characteristics are the appearance of algic and vasomotor symptoms at a segmental level of a limb, in consequence to diverse pathologies (trauma, cardiovascular disease, etc.). The widely accepted theory of a dysregulation of the sympathetic nervous system is nowadays counter-balanced by recent work highlighting the preponderant role of polymodal afferent nerves in the pathophysiology of this disease. The diagnosis, being above-all clinical, is marked by two distinct phases appearing in a variable chronology; a warm phase associating fluctionating pain, stiffness and vasomotor symptoms, and then a cold phase characterized by fibrosis, leading to disabling trophic symptoms. Spontaneous recovery is usual and can be delayed by up to two years, however irreversible sequelae can occur. Paraclinical investigations are necessary to confirm the diagnosis: absence of a biological inflammatory syndrome, early hyperfixation on bone scintography or an abnormality in the MRI signal in the sub-chondral zones. The X-ray shows late local demineralization that is often non-homogenous. The treatment is poorly codified. First-line treatment in France, other than antalgics, often rests on the calcitonins. Intravenous diphosphonates are proposed by some in case of treatment failure. Regional venous blocks are sometimes performed in resistant and disabling forms. Rehabilitation and psychological support have a primordial place throughout the evolution of the illness.

  10. Bidirectional interactions between the baroreceptor reflex and arousal: an update. (United States)

    Silvani, Alessandro; Calandra-Buonaura, Giovanna; Benarroch, Eduardo E; Dampney, Roger A L; Cortelli, Pietro


    Studies involving genetic engineering on animal models and mathematical analysis of cardiovascular signals on humans are shedding new light on the interactions between the arterial baroreceptor reflex (baroreflex) and arousal. Baroreceptor stimulation, if very mild or performed under anaesthesia, may inhibit cortical arousal. However, substantial increases or decreases in baroreflex activation cause arousal in animal models and human subjects in physiological conditions. On the other hand, cardiovascular changes during autonomic arousals and between the states of wakefulness and sleep involve changes in the baroreflex set point and balance with central autonomic commands. Neural connectivity and functional data suggest that the nucleus of the solitary tract, adrenergic C1 neurons of the medulla, and the parabrachial nucleus of the pons mediate the bidirectional interactions between the baroreflex and arousal. These interactions may constitute a positive feedback loop that facilitates sharp and coordinated brain state and autonomic transitions upon arousal: upon arousal, central autonomic commands may increase blood pressure, thereby loading baroreceptors and further increasing arousal. Anomalies of this feedback loop may play a role in the pathophysiology of disease conditions associated with cardiovascular and sleep-wake cycle alterations. These conditions include: obstructive sleep apnoea syndrome, with its association with excessive daytime sleepiness and baroreflex impairment; and insomnia, with its association with autonomic hyperarousal and hypertension. When faced with disorders associated with cardiovascular and sleep-wake cycle alterations, clinical reasoning should entertain the possibility that both conditions are strongly influenced by anomalies of baroreflex function. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Critically Reflexive Theory: A Proposal for Nursing Education

    Directory of Open Access Journals (Sweden)

    Jayne Josephsen


    Full Text Available Nursing is a discipline in transition. As the complexity and acuity of patients increase, nurses are taking on a more comprehensive role in health care leadership and patient outcomes. As the discipline has evolved so has the curricular framework of nursing educational programs, moving from being based on a specific nursing theory, to a general metaparadigm, to the current focus on meeting curricular content standards developed by national accrediting agencies. When considering the skills needed to fully engage in critical thinking and patient advocacy there may be room for an additional curricular focus: that of metacognitive development based on critical theory and constructivism. The empowerment of students via metacognitive and self-evaluative practices also supports the critical theory pedagogy. If graduating nurses are presented with a cohesive and comprehensive curriculum that meets the need for competent and critically reflexive nurses the discipline of nursing can continue to expand in function and voice. The use of metacognition, constructivism, competency, and critical pedagogies in a unified and broad curricular framework allows for the development of these essential skills in contemporary nursing practice. This paper presents this innovative curricular framework that embodies these various teaching and learning perspectives.

  12. Experimental verification of the dominant microwaves from the reflexing electrons

    International Nuclear Information System (INIS)

    Wu, M.W.; Chen, C.Y.; Hwong, C.S.; Guung, T.C.; Tung, K.N.; Hou, W.S.


    At a fixed diode voltage and a cathode-anode gap of 4.5 mm, the frequency of the dominant microwaves scales approximately one-fourth of the diode current for the diode current from 3.7 to 4.9 kA, showing that the dominant microwaves are not generated from the oscillating virtual cathodes. The most persuasive result is that the frequency of the dominant microwaves is kept almost constant as the diode current increases from 4.9 to 7.5 kA, which indicates that these microwaves are generated from the oscillations of the reflexing electrons. The frequency of the dominant microwaves for the overall range of the diode current is 8.0 - 8.5 GHz and the maximum peak power of the microwaves is --40 MW. The complete spectra of the microwaves at various diode current is presented and the components contributed from the oscillations of the virtual cathodes in each spectrum are pointed out

  13. Functional testing of the vestibular ocular reflex (VOR

    Directory of Open Access Journals (Sweden)

    Stefano eRamat


    Full Text Available The experimental assessment of the vestibulo-ocular-reflex (VOR gain provides an objective and quantitative measure of VOR performance which is nonetheless difficult to correlate with its efficiency in everyday living conditions. We developed the Head Impulse Testing Device (HITD based on an inertial sensing system allowing to investigate the functional performance of the VOR by testing its gaze stabilization ability in response to head impulses at different head angular accelerations. HITD results on a population of 39 vestibular patients were compared to those of 22 controls. Overall the sensitivity of the HITD was 92% against the results of the clinical head impulse test and 83% against the clinical diagnosis, while the specificity was 58% against the clinical head impulse test and 83% against the diagnosis. The HITD appears to be a very promising tool for detecting abnormal VOR performance while providing information on the functional performance of the rotational VOR. As compared to the usual testing devices the HITD tests higher frequencies and accelerations that characterize head movements in everyday life activities and provides a functional assessment that is more likely to be related to the subject’s self-feeling.

  14. Nonlinear Modulation of Cutaneous Reflexes with Increasing Speed of Locomotion in Spinal Cats. (United States)

    Hurteau, Marie-France; Thibaudier, Yann; Dambreville, Charline; Chraibi, Anass; Desrochers, Etienne; Telonio, Alessandro; Frigon, Alain


    Cutaneous reflexes are important for responding rapidly to perturbations, correcting limb trajectory, and strengthening support. During locomotion, they are modulated by phase to generate functionally appropriate responses. The goal of the present study was to determine whether cutaneous reflexes and their phase-dependent modulation are altered with increasing speed and if this is accomplished at the spinal level. Four adult cats that recovered stable hindlimb locomotion after spinal transection were implanted with electrodes to record hindlimb muscle activity chronically and to stimulate the superficial peroneal nerve electrically to evoke cutaneous reflexes. The speed-dependent modulation of cutaneous reflexes was assessed by evoking and characterizing ipsilateral and contralateral responses in semitendinosus, vastus lateralis, and lateral gastrocnemius muscles at four treadmill speeds: 0.2, 0.4, 0.6, and 0.8 m/s. The amplitudes of ipsilateral and contralateral responses were largest at intermediate speeds of 0.4 and 0.6 m/s, followed by the slowest and fastest speeds of 0.2 and 0.8 m/s, respectively. The phase-dependent modulation of reflexes was maintained across speeds, with ipsilateral and contralateral responses peaking during the stance-to-swing transition and swing phase of the ipsilateral limb or midstance of the contralateral limb. Reflex modulation across speeds also correlated with the spatial symmetry of the locomotor pattern, but not with temporal symmetry. That the cutaneous reflex amplitude in all muscles was similarly modulated with increasing speed independently of the background level of muscle activity is consistent with a generalized premotoneuronal spinal control mechanism that could help to stabilize the locomotor pattern when changing speed. SIGNIFICANCE STATEMENT When walking, receptors located in the skin respond to mechanical pressure and send signals to the CNS to correct the trajectory of the limb and to reinforce weight support. These

  15. Intersession reliability of Hoffmann reflex gain and presynaptic inhibition in the human soleus muscle. (United States)

    Hayes, Bradley T; Hicks-Little, Charlie A; Harter, Rod A; Widrick, Jeffrey J; Hoffman, Mark A


    Hayes BT, Hicks-Little CA, Harter RA, Widrick JJ, Hoffman MA. Intersession reliability of Hoffmann reflex gain and presynaptic inhibition in the human soleus muscle. To determine the day-to-day reliability of Hoffmann reflex (H-reflex) gain and presynaptic inhibition of spinal reflexes in the human soleus muscle. Controlled trial. Research laboratory. Volunteers (N=30; mean +/- SD age, 23.4+/-3.9y; height, 175.64+/-10.87cm; mass, 84.50+/-24.18kg) with no history of lower extremity pathology and/or injury participated. Subjects lay prone with the head, shoulders, arms, and hips supported in a static position by a massage body pillow and the ankle positioned at 90 degrees . Recording electrodes were placed over the soleus and tibialis anterior muscle bellies, and the stimulating electrodes were positioned over the tibial nerve in the popliteal space and the common peroneal nerve near the fibular head. The H-reflex and motor wave recruitment curves were then measured and recorded. Presynaptic inhibition was also assessed in the soleus muscle, and a conditioning stimulation of the common peroneal nerve (1 x motor threshold = motor threshold) was used prior to soleus H-reflex measurement. Two testing sessions took place between 2 and 7 days, and each session occurred at the same time of day. Assessments of H-reflex gain and presynaptic inhibition yielded test-retest reliability of R equal to . 95 and .91, respectively. Measures of presynaptic inhibition and H-reflex gain (H slope/M slope) in the human soleus muscle are consistent and reliable day to day.

  16. How do occupational therapists engage in reflexive professional practice while completing a programme evaluation?


    Mellors, Matt


    non-peer-reviewed Aim: The purpose of this qualitative study is to understand how occupational therapists engage in reflexive professional practice while completing an 8 week programme for unemployed people. The study proposes to identify key elements of reflexivity and discuss what stimulates this process in practice. Methods: Six occupational therapists recorded their reflections on delivering an 8 week intervention in a weekly written journal. Post intervention interviews...

  17. [Vestibular-spinal reflex in patients with vestibular-ataxic syndrome of different genesis]. (United States)

    Kuznetsova, E A; Iakupov, E Z


    The article presents the results of investigation of vestibular-spinal reflex (vestibular myogenic evoked potentials) in healthy subjects and patients with vestibular-ataxic syndrome. The inhibition of vestibular-spinal reflex with the P13 latency increase was shown to be the most characteristic of demyelinating and traumatic brain diseases. The P13 latency increase was not pathognomic for any disease of the nervous system but was indicative of conduction delay in vestibular-spinal tracts.

  18. Tibialis anterior stretch reflex in early stance is suppressed by repetitive transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Zuur, Abraham T; Christensen, Mark Schram; Sinkjær, Thomas


    Abstract A rapid plantar flexion perturbation in the early stance phase of walking elicits a large stretch reflex in tibialis anterior (TA). In this study we use repetitive Transcranial Magnetic Stimulation (rTMS) to test if this response is mediated through a transcortical pathway. TA stretch...... reflexes were elicited in the early stance phase of the step cycle during treadmill walking. 20 minutes of 1 Hz rTMS at 115% resting motor threshold (MTr) significantly decreased (p

  19. Frequency response of vestibular reflexes in neck, back, and lower limb muscles. (United States)

    Forbes, Patrick A; Dakin, Christopher J; Vardy, Alistair N; Happee, Riender; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien


    Vestibular pathways form short-latency disynaptic connections with neck motoneurons, whereas they form longer-latency disynaptic and polysynaptic connections with lower limb motoneurons. We quantified frequency responses of vestibular reflexes in neck, back, and lower limb muscles to explain between-muscle differences. Two hypotheses were evaluated: 1) that muscle-specific motor-unit properties influence the bandwidth of vestibular reflexes; and 2) that frequency responses of vestibular reflexes differ between neck, back, and lower limb muscles because of neural filtering. Subjects were exposed to electrical vestibular stimuli over bandwidths of 0-25 and 0-75 Hz while recording activity in sternocleidomastoid, splenius capitis, erector spinae, soleus, and medial gastrocnemius muscles. Coherence between stimulus and muscle activity revealed markedly larger vestibular reflex bandwidths in neck muscles (0-70 Hz) than back (0-15 Hz) or lower limb muscles (0-20 Hz). In addition, vestibular reflexes in back and lower limb muscles undergo low-pass filtering compared with neck-muscle responses, which span a broader dynamic range. These results suggest that the wider bandwidth of head-neck biomechanics requires a vestibular influence on neck-muscle activation across a larger dynamic range than lower limb muscles. A computational model of vestibular afferents and a motoneuron pool indicates that motor-unit properties are not primary contributors to the bandwidth filtering of vestibular reflexes in different muscles. Instead, our experimental findings suggest that pathway-dependent neural filtering, not captured in our model, contributes to these muscle-specific responses. Furthermore, gain-phase discontinuities in the neck-muscle vestibular reflexes provide evidence of destructive interaction between different reflex components, likely via indirect vestibular-motor pathways.

  20. VizieR Online Data Catalog: REFLEX II. Properties of the survey (Boehringer+ 2013) (United States)

    Boehringer, H.; Chon, G.; Collins, C. A.; Guzzo, L.; Nowak, N.; Bobrovskyi, S.


    Like REFLEX I, the extended survey covers the southern sky outside the band of the Milky Way (|bII|>=20°) with regions around the Magellanic clouds excised (3 in LMC, 3 in SMC). The total survey area after this excision amounts to 4.24 steradian (or 13924°2) which corresponds to 33.75% of the sky. Different from REFLEX I, we use the refined RASS product RASS III (Voges et al. 1999, Cat. IX/10). (2 data files).

  1. Modulation of the visceromotor reflex by a lumbosacral ventral root avulsion injury and repair in rats


    Chang, Huiyi H.; Havton, Leif A.


    Increased abdominal muscle wall activity may be part of a visceromotor reflex (VMR) response to noxious stimulation of the bladder. However, information is sparse regarding the effects of cauda equina injuries on the VMR in experimental models. We studied the effects of a unilateral L6-S1 ventral root avulsion (VRA) injury and acute ventral root reimplantation (VRI) into the spinal cord on micturition reflexes and electromyographic activity of the abdominal wall in rats. Cystometrogram (CMG) ...

  2. The Effects of State Anxiety on Hoffman (H Reflex Parameters in Female University Students

    Directory of Open Access Journals (Sweden)

    Ali Delavar


    Full Text Available Background and Aim: Anxiety, as one of the most common and costly problems in Iran and all over the world, comprises both physical and mental disorders. Previous research has proposed that spinal reflex modulation may mediate anxiety-related changes in postural control. This study aimed to investigate if the H-reflex parameters are influenced by state anxiety. Materials and Methods: A group of 20 healthy female university students with a low anxiety score (lower than 42, based upon the Schpilberger’s questionnaire were recruited in this study and the H-reflex of their Soleus muscle was recorded in four positions. The tested positions included the standard prone lying (the reference position, standing on level ground; and two stability threatening positions including standing on the center and at the edge of a one-meter height stool. The outcome measures were the latency, amplitude and the amplitude needed to record the reflex. Results: No significant differences were shown in the latency of the H-reflex among the four tested positions (p>0.05. In terms of the amplitude of the reflex, however, significant differences were found between all positions when compared to the reference position (prone lying (p=0.001. There are significant differences among all four positions in amplitude needed to record the H-reflex (p=0.034, while the Bonferoni test revealed the significant difference only between the position of standing at the edge of the height relative to the standard prone lying position (p=0.041. Conclusion: The results of this study showed that any postural perturbation results in brain activities and affects more on the amplitudes rather than the latency of the H-reflex. These findings may be helpful in a better understanding of the standing balance in healthy people and people suffering from postural instabilities, fear of falling, elderly persons and also hemiplegic patients.

  3. The effect of sex and chronic low back pain on back muscle reflex responses. (United States)

    Larivière, Christian; Forget, Robert; Vadeboncoeur, Roger; Bilodeau, Martin; Mecheri, Hakim


    Different back muscle reflex assessment protocols have shown abnormally longer reflex latency responses of back muscles in chronic low back pain (CLBP). However, many confounding variables are difficult to control, such as the load magnitude and the preactivation of trunk muscles. The aims of this study were to evaluate, in 30 subjects with CLBP and 30 healthy controls, the activation levels of back muscles during pre-loading and their reflex responses to sudden loading. After subjected to six practice perturbations, 20 sudden and unexpected forward perturbations of the trunk were applied in 30 CLBP subjects (14 women) and 31 controls (17 women), while attempting to minimize the confounding effect of preactivation level and perturbation amplitude. Reflex latency and amplitudes were computed from the surface EMG signals of four back muscles (bilaterally at L5, L3, L1, T10 vertebral levels). EMG was also collected from abdominal muscles. Subjects with CLBP significantly increased the preactivation of back muscles (abdominal preactivation the same) relative to controls while no sex effect was observed. While adjusting statistically for these differences, reflex amplitude was significantly higher in subjects with CLBP and men, compared to healthy controls and women, respectively. Interestingly, contrary to most of the literature available, no between-group effects were detected for reflex latency, which could potentially be explained by an appropriate control of confounding variables, but this remains to be clarified in future research.

  4. Educational Strategies to Enhance Reflexivity Among Clinicians and Health Professional Students: A Scoping Study

    Directory of Open Access Journals (Sweden)

    Rachel Landy


    Full Text Available Reflexivity involves the ability to understand how one's social locations and experiences of advantage or disadvantage have shaped the way one understands the world. The capacity for reflexivity is crucial because it informs clinical decisions, which can lead to improvements in service delivery and patient outcomes. In this article, we present a scoping study that explored educational strategies designed to enhance reflexivity among clinicians and/or health profession students. We reviewed articles and grey literature that address the question: What is known about strategies for enhancing reflexivity among clinicians and students in health professional training programs? We searched multiple databases using keywords including: reflexivity, reflective, allied health professionals, pedagogy, learning, and education. The search strategy was iterative and involved three reviews. Each abstract was independently reviewed by two team members. Sixty-eight texts met the inclusion criteria. There was great diversity among the educational strategies and among health professions. Commonalities across strategies were identified related to reflective writing, experiential learning, classroom-based activities, continuing education, and online learning. We also summarize the 19 texts that evaluated educational strategies to enhance reflexivity. Further research and education is urgently needed for more equitable and socially-just health care. URN:

  5. Long-latency reflexes account for limb biomechanics through several supraspinal pathways

    Directory of Open Access Journals (Sweden)

    Isaac Louis Kurtzer


    Full Text Available Accurate control of body posture is enforced by a multitude of corrective actions operating over a range of time scales. The earliest correction is the short-latency reflex which occurs between 20-45 ms following a sudden displacement of the limb and is generated entirely by spinal circuits. In contrast, voluntary reactions are generated by a highly distributed network but at a significantly longer delay after stimulus onset (greater than 100 ms. Between these two epochs is the long-latency reflex (around 50-100 ms which but acts more rapidly than of voluntary reactions but shares some supraspinal pathways and functional capabilities. In particular, the long-latency reflex accounts for the arm’s biomechanical properties rather than only responding to local muscle stretch like the short-latency reflex. This paper will review how the long-latency reflex accounts for the arm’s biomechanical properties and the supraspinal pathways supporting this ability. Relevant experimental paradigms include clinical studies, non-invasive brain stimulation, neural recordings in monkeys, and human behavioral studies. The sum of this effort indicates that primary motor cortex and reticular formation contribute to the the long-latency reflex either by generating or scaling its structured response appropriate for the arm’s biomechanics whereas the cerebellum scales the magnitude of the feedback response. Additional putative pathways are discussed as well as potential research lines.

  6. Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help. (United States)

    Thompson, Aiko K; Wolpaw, Jonathan R


    People with incomplete spinal cord injury (SCI) frequently suffer motor disabilities due to spasticity and poor muscle control, even after conventional therapy. Abnormal spinal reflex activity often contributes to these problems. Operant conditioning of spinal reflexes, which can target plasticity to specific reflex pathways, can enhance recovery. In rats in which a right lateral column lesion had weakened right stance and produced an asymmetrical gait, up-conditioning of the right soleus H-reflex, which increased muscle spindle afferent excitation of soleus, strengthened right stance and eliminated the asymmetry. In people with hyperreflexia due to incomplete SCI, down-conditioning of the soleus H-reflex improved walking speed and symmetry. Furthermore, modulation of electromyographic activity during walking improved bilaterally, indicating that a protocol that targets plasticity to a specific pathway can trigger widespread plasticity that improves recovery far beyond that attributable to the change in the targeted pathway. These improvements were apparent to people in their daily lives. They reported walking faster and farther, and noted less spasticity and better balance. Operant conditioning protocols could be developed to modify other spinal reflexes or corticospinal connections; and could be combined with other therapies to enhance recovery in people with SCI or other neuromuscular disorders. © The Author(s) 2014.

  7. Trigeminal cardiac reflex: new thinking model about the definition based on a literature review. (United States)

    Meuwly, C; Golanov, E; Chowdhury, T; Erne, P; Schaller, B


    Trigeminocardiac reflex (TCR) is a brainstem reflex that manifests as sudden onset of hemodynamic perturbation in blood pressure (MABP) and heart rate (HR), as apnea and as gastric hypermotility during stimulation of any branches of the trigeminal nerve. The molecular and clinical knowledge about the TCR is in a constant growth since 1999, what implies a current need of a review about its definition in this changing context. Relevant literature was identified through searching in PubMed (MEDLINE) and Google scholar database for the terms TCR, oculocardiac reflex, diving reflex, vasovagale response. The definition of the TCR varies in clinical as well as in research studies. The main difference applies the required change of MABP and sometimes also HR, which most varies between 10% and 20%. Due to this definition problem, we defined, related to actual literature, 2 major (plausibility, reversibility) and 2 minor criteria (repetition, prevention) for a more proper identification of the TCR in a clinical or research setting. Latest research implies that there is a need for a more extended classification with 2 additional subgroups, considering also the diving reflex and the brainstem reflex. In this review, we highlighted criteria for proper definition and classification of the TCR in the light of increased knowledge and present a thinking model to overcome this complexity. Further we separately discussed the role of HR and MABP and their variation in this context. As another subtopic we gave attention to is the chronic TCR; a variant that is rarely seen in clinical medicine.

  8. Reflex inhibition of electrically induced muscle cramps in hypohydrated humans. (United States)

    Miller, Kevin C; Mack, Gary W; Knight, Kenneth L; Hopkins, J Ty; Draper, David O; Fields, Paul J; Hunter, Iain


    Anecdotal evidence suggests that ingesting small volumes of pickle juice relieves muscle cramps within 35 s of ingestion. No experimental evidence exists supporting the ingestion of pickle juice as a treatment for skeletal muscle cramps. On two different days (1 wk apart), muscle cramps were induced in the flexor hallucis brevis (FHB) of hypohydrated male subjects (approximately 3% body weight loss and plasma osmolality approximately 295 mOsm x kg(-1) H2O) via percutaneous tibial nerve stimulation. Thirty minutes later, a second FHB muscle cramp was induced and was followed immediately by the ingestion of 1 mL x kg(-1) body weight of deionized water or pickle juice (73.9 +/- 2.8 mL). Cramp duration and FHB EMG activity during the cramp were quantified, as well as the change in plasma constituents. Cramp duration (water = 151.9 +/- 12.9 s and pickle juice = 153.2 +/- 23.7 s) and FHB EMG activity (water = 60% +/- 6% and pickle juice = 68% +/- 9% of maximum voluntary isometric contraction EMG activity) were similar during the initial cramp induction without fluid ingestion (P > 0.05). During FHB muscle cramp induction combined with fluid ingestion, FHB EMG activity was again similar (water = 55% +/- 9% and pickle juice = 66% +/- 9% of maximum voluntary isometric contraction EMG activity, P > 0.05). However, cramp duration was 49.1 +/- 14.6 s shorter after pickle juice ingestion than water (84.6 +/- 18.5 vs 133.7 +/- 15.9 s, respectively, P cramps in hypohydrated humans. This effect could not be explained by rapid restoration of body fluids or electrolytes. We suspect that the rapid inhibition of the electrically induced cramps reflects a neurally mediated reflex that originates in the oropharyngeal region and acts to inhibit the firing of alpha motor neurons of the cramping muscle.

  9. Frequency response of human vestibular reflexes characterized by stochastic stimuli. (United States)

    Dakin, Christopher J; Son, Gregory M Lee; Inglis, J Timothy; Blouin, Jean-Sébastien


    Stochastic vestibular stimulation (SVS) can be used to study the postural responses to unpredictable vestibular perturbations. The present study seeks to determine if stochastic vestibular stimulation elicits lower limb muscular responses and to estimate the frequency characteristics of these vestibulo-motor responses in humans. Fourteen healthy subjects were exposed to unpredictable galvanic currents applied on their mastoid processes while quietly standing (+/-3 mA, 0-50 Hz). The current amplitude and stimulation configuration as well as the subject's head position relative to their feet were manipulated in order to determine that: (1) the muscle responses evoked by stochastic currents are dependent on the amplitude of the current, (2) the muscle responses evoked by stochastic currents are specific to the percutaneous stimulation of vestibular afferents and (3) the lower limb muscle responses exhibit polarity changes with different head positions as previously described for square-wave galvanic vestibular stimulation (GVS) pulses. Our results revealed significant coherence (between 0 and 20 Hz) and cumulant density functions (peak responses at 65 and 103 ms) between SVS and the lower limbs' postural muscle activity. The polarity of the cumulant density functions corresponded to that of the reflexes elicited by square-wave GVS pulses. The SVS-muscle activity coherence and time cumulant functions were modulated by current amplitude, electrode position and head orientation with respect to the subject's feet. These findings strongly support the vestibular origin of the lower limb muscles evoked by SVS. In addition, specific frequency bandwidths in the stochastic vestibular signal contributed to the early (12-20 Hz) and late components (2-10 Hz) of the SVS-evoked muscular responses. These frequency-dependent SVS-evoked muscle responses support the view that the biphasic muscle response is conveyed by two distinct physiological processes.

  10. [Developing team reflexivity as a learning and working tool for medical teams]. (United States)

    Riskin, Arieh; Bamberger, Peter


    Team reflexivity is a collective activity in which team members review their previous work, and develop ideas on how to modify their work behavior in order to achieve better future results. It is an important learning tool and a key factor in explaining the varying effectiveness of teams. Team reflexivity encompasses both self-awareness and agency, and includes three main activities: reflection, planning, and adaptation. The model of briefing-debriefing cycles promotes team reflexivity. Its key elements include: Pre-action briefing--setting objectives, roles, and strategies the mission, as well as proposing adaptations based on what was previously learnt from similar procedures; Post-action debriefing--reflecting on the procedure performed and reviewing the extent to which objectives were met, and what can be learnt for future tasks. Given the widespread attention to team-based work systems and organizational learning, efforts should be made toward ntroducing team reflexivity in health administration systems. Implementation could be difficult because most teams in hospitals are short-lived action teams formed for a particular event, with limited time and opportunity to consciously reflect upon their actions. But it is precisely in these contexts that reflexive processes have the most to offer instead of the natural impulsive collective logics. Team reflexivity suggests a potential solution to the major problems of iatorgenesis--avoidable medical errors, as it forces all team members to participate in a reflexive process together. Briefing-debriefing technology was studied mainly in surgical teams and was shown to enhance team-based learning and to improve quality-related outcomes and safety.

  11. Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems (United States)

    Cionni, Robert J.; Pei, Ron; Dimalanta, Ramon; Lubeck, David


    Purpose To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. Methods This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Results Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. Conclusions The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. Translational Relevance This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery. PMID:26290778

  12. Persistence of locomotor-related interlimb reflex networks during walking after stroke. (United States)

    Zehr, E Paul; Loadman, Pamela M


    Cutaneous nerve stimulation evokes coordinated and phase-modulated reflex output widely distributed to muscles of all four limbs during walking. Accessibility to this distributed network after stroke offers insight into the pathological changes and suggests utility for therapeutic applications. Here we examined muscles in both the more (MA) and less affected (LA) legs evoked by stimulation at the ankle and wrist during walking in chronic (>6 months post CVA) stroke. Stroke and control participants walked on a treadmill with a harness support system. Reflexes were evoked with trains of electrical stimuli delivered separately to the cutaneous superficial peroneal (SP; at the ankle) and superficial radial (SR; at the wrist) nerves. Background locomotor and reflex EMG were phase-averaged across the gait cycle and analyzed off line. Locomotor background muscle activation patterns were altered bilaterally in stroke, as compared with control. Phase-dependent modulation of interlimb cutaneous reflexes was found in both stroke and control subjects with stimulation of each nerve, but responses were blunted in stroke. Reflex reversal in tibialis anterior (TA) at heel strike with SP nerve stimulation was present in both groups. Notably, SR nerve stimulation produced facilitation during the swing-to-stance transition in the TA and suppression of MG in the MA leg during stance. Interlimb cutaneous inputs may access coordinated reflex pathways in the MA limb during walking after stroke. Importantly activation in these pathways could provoke responses to counter foot drop during swing phase of walking. Additionally, our data support the perspective that there is no "unaffected" side after stroke and that caution should be used when interpreting the LA side as "control" after stroke. The presence of functionally-relevant interlimb cutaneous reflexes in the MA leg presents a substrate that may be strengthened by rehabilitation. Copyright © 2011 International Federation of Clinical

  13. Stretch reflex excitability of the anti-gravity ankle extensor muscle in elderly humans. (United States)

    Kawashima, N; Nakazawa, K; Yamamoto, S-I; Nozaki, D; Akai, M; Yano, H


    To examine whether the stretch reflex excitability of the soleus muscle changes with age, stretch reflexes at rest (REST) and during weak voluntary contractions (ACT) were elicited in 18 older and 14 younger subjects. The amplitude of the stretch reflex responses and gain, defined as the gradient of the regression line for the relation between stretch reflex responses against the angular velocity of the applied perturbation, were evaluated in each short-latency (M1) and two long-latency components (M2 and M3). It was found that in the older group, both the amplitude and gain of the M1 component did not change from the REST to the ACT conditions, whereas in the younger group both variables significantly increased from the REST to ACT conditions. The latency of the M1 component was significantly shorter under the REST condition (older vs. younger: 51.8 +/- 7.37 vs. 55.1 +/- 8.69 ms), while no group differences were found in those variables under the ACT condition, suggesting that the muscle-tendon complexes of SOL muscles of the older subjects were less elastic and had less slack, probably due to age-related histochemical alterations. Further, the Hoffman reflex (H-reflex), elicited during the REST condition in 10 older and 11 younger subjects showed no significant differences, suggesting that the soleus motoneuron response to the Ia input was comparable between the two subject groups. The histochemical alterations occurring with the ageing process might augment the short-latency stretch reflex in the SOL muscle without enhancement of motoneuronal excitability, and this effect might be masked when the muscle is voluntarily activated.

  14. Prognostic Value of Impaired Preoperative Ankle Reflex in Surgical Outcome of Lumbar Disc Herniation

    Directory of Open Access Journals (Sweden)

    Farzad Omidi-Kashani


    Full Text Available Background: Several prognostic factors exist influencing the outcome of surgical discectomy in the patients with lumbar disc herniation (LDH. The aim of this study is to evaluate the relationship between severity of preoperative impaired ankle reflex and outcomes of lumbar discectomy in the patients with L5-S1 LDH. Methods: We retrospectively evaluated 181 patients (108 male and 73 female who underwent simple discectomy in our orthopedic department from April 2009 to April 2013 and followed them up for more than one year. The mean age of the patients was 35.3±8.9 years old. Severity of reflex impairment was graded from 0 to 4+ and radicular pain and disability were assessed by visual analogue scale (VAS and Oswestry disability index (ODI questionnaires, respectively. Subjective satisfaction was also evaluated at the last follow-up visit. Chi-square and Kruskal-Wallis tests were used to compare qualitative variables. Results: Reflex impairment existed in 44.8% preoperatively that improved to 10% at the last follow-up visit. Statistical analyses could not find a significant relationship between the severity of impaired ankle reflex and sex or age (P=0.538 and P=0.709, respectively. There was a remarkable relationship between severity of reflex impairment and preoperative radicular pain or disability (P=0.012 and P=0.002, respectively. Kruskal-Wallis test showed that a more severity in ankle reflex impairment was associated with not only less improvement in postoperative pain and disability but also less satisfaction rate (P Conclusions: In the patients with L5-S1 LDH, more severe ankle reflex impairment is associated with less improvement in postoperative pain, disability, and subjective satisfaction.

  15. Parasympathetic nervous system dysfunction, as identified by pupil light reflex, and its possible connection to hearing impairment


    Wang, Yang; Zekveld, Adriana A.; Naylor, Graham; Ohlenforst, Barbara; Jansma, Elise P.; Lorens, Artur; Lunner, Thomas; Kramer, Sophia E.


    Context\\ud Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown.\\ud \\ud Objectives\\ud To 1) review the evidence for the pupil light reflex being a sensitive meth...

  16. Development of Functional Recovery Training Device for Hemiplegic Fingers with Finger-expansion Facilitation Exercise by Stretch Reflex (United States)

    Yu, Yong; Iwashita, Hisashi; Kawahira, Kazumi; Hayashi, Ryota

    This paper develops a functional recovery training device to perform repetition facilitating exercise for hemiplegic finger rehabilitation. On the facilitation exercise, automatic finger expansion can be realized and facilitated by stretch reflex, where a stimulation forces is applied instantaneously on flexion finger for making strech reflex and resistance forces are applied for maintaining the strech reflex. In this paper, novel parallel mechanisms, force sensing system with high sensitivity and resistance accompanying cooperation control method are proposed for sensing, controlling and realizing the stimulation force, resistance forces, strech reflex and repetition facilitating exercise. The effectivities and performances of the device are shown by some experiments.

  17. A Study on the Effects of Bee Venom Aqua-Acupuncture on Writhing Reflex

    Directory of Open Access Journals (Sweden)

    Jeong Sun-Hee


    Full Text Available Introduction:In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation on effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex Materials and Methods:Pain animal model was used acetic acid method. The changes of writhing reflex of the mice which were derived pain by injecting acetic acid into the abdomen, after stimulating Bee Venom aqua-acupuncture on Chungwan(CV12 and non acupuncture point on the backside were measured. Results:1. It showed that the writhing reflex were appeared on the groups which injected acetic acid only, and saline-acetic acid group(sample I, but not on the group bee venom-saline group(sample II. 2. The change of writhing reflex by Chungwan(CV12 Bee Venom aqua-acupuncture showed significant decrease in the order of Chungwan(CV12 Bee Venom aqua-acupuncture group III(2.5×10-3g/kg, II(2.5×10-4g/kg, and I(2.5×10-5g/kg, compared with control group. There were significant decrease of number of writhing reflex in 5~10, 10~15 and 15~20 minutes intervals of Chung wan(CV12 Bee Venom aqua-acupuncture group I, and in 0~5, 5~10, 10~15 and 15~20 minutes intervals of II and III, compared with control group. 3. The change of writhing reflex by non acupuncture point Bee Venom aqua-acupuncture showed significant decrease in the 0~5 and 5~10 minutes intervals and the total number of writhing reflex in 2.5×10-4g/kg group, compared with control group 4. The effects of writhing reflex of Chungwan(CV12 Bee Venom aqua-acupuncture group showed significant decrease, compared with non acupuncture point Bee Venom aqua-acupuncture group. Conclusion:This study shows that the Bee Venom aqua-acupuncture on Chungwan(CV12 decreases the numbers of writhing reflex. As the

  18. Early Modern ET, Reflexive Telescopics, and Their Relevance Today (United States)

    Danielson, Dennis

    The period from the discovery of Tycho's New Star in 1572 to Galileo's "geometrization of astronomical space" in 1610 (and the years following) saw the disintegration of the boundary between the sublunary and superlunary spheres—between the "lower storey" and "upper storey" of the Aristotelian Universe. This establishment of a strong physical affinity between the universe "up there" and the earthly realm "down here" was also complemented by the rise of Copernicanism: for once the Earth was seen as a planet, the other planets could readily be imagined as other Earths. This analogy suggested not only physical but also biological affinities and supported the plausibility of humans' capacity to travel to the Moon and beyond. Robert Burton—given the demise of Aristotle's physics—declared in 1621 that "If the heavens be penetrable … it were not amiss in this aerial progress to make wings and fly up." John Wilkins and Francis Godwin in the 1630s actively imagined creatures in the Moon and human journeys thither. The epic poet John Milton in 1667 hinted that "every star [is] perhaps a world / Of destined habitation." Moreover, space travel was no one-way street: Thomas Traherne in the 1670s imagined a dweller among the stars visiting Earth and remarking on what must be the condition of its inhabitants. In these and other ways, seventeenth-century writers offered serious and impressive speculation about extraterrestrial life and its possible perceptions of Earth. Such speculations remain pertinent to astrobiological theory today. What Hans Blumenberg in the 1970s called "reflexive telescopics"—the examination of Earth from an imagined extraterrestrial viewpoint—is an important counterpart to the search for life "out there." It serves as a reminder of the obvious but profound premise that Earth is part of the cosmos. At a popular level we often continue to speak of "outer space" as if the old "two-storey" picture of the universe still had some residual legitimacy

  19. Algumas reflexões sobre a Ética Desportiva

    Directory of Open Access Journals (Sweden)

    Carla Marisa Moreira


    Full Text Available Numa sociedade em que os valores estão em constantes alterações no comportamento de cada indivíduo, a identificação desses mesmos valores nos jovens atletas é de vital importância para melhor se entender o processo pelo qual eles tomam determinadas decisões, em situações desportivas. As questões associadas à ética no desporto, e mais especificamente as que dizem respeito ao espírito desportivo e à tolerância, assumem hoje uma importância acrescida. De facto, não podemos negar a importância, nos diversos âmbitos, da prática e do espectáculo desportivo, mas há que reconhecer também que eles se revelam como campos especiais, nos quais os fins – ganhar – justificam quaisquer meios – violência, a corrupção, a fraude, o querer ganhar a todo e qualquer custo, o doping, a deslealdade, a ausência de espírito desportivo, etc. A Ética Desportiva surge como uma estrutura moral que define alguns limites para o comportamento dos desportistas, de forma a preservar um sistema desportivo civilizado. É possível competir respeitando o adversário, reconhecendo o seu valor e competência, vendo-o como um oponente indispensável, sem o qual não existe competição. Vários investigadores defendem que a participação, das crianças e jovens, em actividades desportivas contribui para um desenvolvimento global e harmonioso das mesmas, pelo que se deverá dar atenção à importância do espírito desportivo como componente do processo de desenvolvimento da criança e jovem. Com este trabalho pretendeu-se apresentar algumas reflexões sobre a aquisição de valores e princípios no contexto desportivo.

  20. Eye gaze triggers reflexive attention shifts: evidence from lateralised ERPs. (United States)

    Feng, Qing; Zhang, Xuemin


    Social cues, such as another individual׳s eye gaze, provide valuable information regarding the actions and intentions of others. Previous studies have suggested that seeing another׳s gaze automatically orients one׳s attention in the gaze direction. In this event-related potential (ERP) study, a spatial cuing paradigm was combined with a visual search task in which targets were defined by feature conjunctions in order to eliminate effects of target/distractor salience. Participants viewed centrally presented faces with neutral expressions in which eyes looked to the left or right. The participants׳ task was to identify a target object (with or without gap) defined by a combination of shape and orientation, which appeared in either the same (cued) or the opposite (uncued) location as the direction of the eye gaze. There was behavioural evidence of a gaze congruency effect, as reaction times (RTs) were faster when the eyes looked towards the target rather than away from the location of the target. The ERP data indicated the presence of significant gaze-congruent early directing attention negativity (EDAN) and anterior directing attention negativity (ADAN), reflecting attention shifts to the cued location in advance of the target presentation. ERP data did not show evidence of later orienting of attention triggered by gaze cues in the late attention-directing attention positivity (LDAP) at posterior sites. The results disclosed the neural response during reflexive attention shifting triggered by gazes and ascertained the relationship among EDAN, ADAN, LDAP and gaze-elicited attention shifts. After the presentation of the target array without salient stimuli, the presence of the N2-posterior-contralateral (N2pc) in the cued trials and the absence in the uncued trials further supported that attention had been directed to the possible target location prior to the target onset. The ERPs in response to the target array also extend our understanding of the neural

  1. Effects of bromantan on offspring maturation and development of reflexes. (United States)

    Iezhitsa, I N; Spasov, A A; Bugaeva, L I


    Bromantan (N-[2-adamantil]-N-[para-bromphenyl]amine) is an "actoprotective" drug widely used in Russia as a muscle performance-enhancing agent for sportsmen and as an immunostimulator in medicine. Experiments were conducted to determine whether this compound has adverse effects on the reproduction and development of offspring. Sexually mature female rats, weighing 180-200 g, were orally given bromantan at doses of 30 mg/kg (30-mg/kg group), 150 mg/kg (150-mg/kg group) and 600 mg/kg (600-mg/kg group) daily for 16 days, while the controls received the vehicle, amylaceous solution. Afterwards, treated females were mated with untreated males. The body weight change of the pregnant rats was monitored, as well as the length of gestation, litter size, sex ratio and number of stillborn. The offsprings were weighed and observed for external malformations, abnormalities of conditioned and unconditioned reflexes and open-field behaviour. Observation of rat dams revealed that their general state and activity in all groups did not differ significantly both during and after bromantan treatment. Bromantan had no adverse effects on body weight and gestation length of dams. Number of dams delivered per group did not differ from controls. There were stillborn rat pups in all litters, but the control group had less. One dam in the first group delivered a rat pup with a head hematoma. Litter size of the 30- and 600-mg/kg groups was decreased (by 34.9% and 44.2%, respectively) and increased in the 150-mg/kg group (by 45.1%, POpen-field testing (PND 40) resulted in an insignificant decrease of exploratory and locomotor behaviors for the 30-, 150- and 600-mg/kg groups. The number of grooming episodes was insignificantly decreased for the 30-mg/kg group and insignificantly increased for the 600-mg/kg group. In the passive avoidance testing, on the retention day (72 h later), entry latency for rat pups in the 30-, 150- and 600-mg/kg groups increased by 259.0%, 175.3% and 160

  2. Improvement of the Marginal Reflex Distance-1 in Blepharoptosis Surgeries. (United States)

    Hwang, Kun; Ko, Yeong Seung


    The aim of this study was to predict the improvement of the marginal reflex distance (MRD1) in each blepharoptosis surgery.In PubMed and Scopus, the search terms 1. (blepharoptosis) AND 2. (surgery) AND 3. (levator OR outcome OR MRD OR function OR ptosis amount) were used and 1268 titles were found. Among them 28 papers were analyzed: Aponeurotic surgery (A-group, 8), Muller muscle resection (M-group, 10), Levator resection (L-group, 4), and Frontalis suspension (F-group, 6).The preop-MRD1 was greatest in L-group (1.7 ± 1.0 mm) followed by the A-group (1.3 ± 0.5 mm) and the M-group (1.3 ± 0.5 mm). The F-group had the lowest (-0.4 ± 0.7 mm). Age was oldest in the M-group (58.6 ± 11.9 years) followed by the A-group (42.4 ± 18.9 years) and the F-group (27.2 ± 17.9 years). The L-group was the youngest (18.9 ± 11.5 years). The mean improved amount of MRD1 (ΔL) was 2.15 ± 0.90 mm. The ΔL was different among the four operative methods. The F-group was greatest (2.4 ± 1.5 mm) followed by the A-group (2.3 ± 0.5 mm) and the M-group (2.0 ± 0.6 mm). The L-group had the least improved amount of MRD1 (1.8 ± 0.8 mm). There were significant differences between the groups (P < 0.05), except between the F-group and the A-group (P = 0.284). The mean follow-up period was 8.1 ± 7.0 months. In the 3 groups except A-group, the ΔL decreased in follow-up periods, with different degree of decrement. Only in A-group, ΔL increased slightly in follow-up periods. We think this is due to relatively well preserved levator function and short follow-up period (5.4 ± 3.3 months) of A-group patients.The results of this review can be used in choosing blepharoptosis correction methods.

  3. Priming Neural Circuits to Modulate Spinal Reflex Excitability (United States)

    Estes, Stephen P.; Iddings, Jennifer A.; Field-Fote, Edelle C.


    While priming is most often thought of as a strategy for modulating neural excitability to facilitate voluntary motor control, priming stimulation can also be utilized to target spinal reflex excitability. In this application, priming can be used to modulate the involuntary motor output that often follows central nervous system injury. Individuals with spinal cord injury (SCI) often experience spasticity, for which antispasmodic medications are the most common treatment. Physical therapeutic/electroceutic interventions offer an alternative treatment for spasticity, without the deleterious side effects that can accompany pharmacological interventions. While studies of physical therapeutic/electroceutic interventions have been published, a systematic comparison of these approaches has not been performed. The purpose of this study was to compare four non-pharmacological interventions to a sham-control intervention to assess their efficacy for spasticity reduction. Participants were individuals (n = 10) with chronic SCI (≥1 year) who exhibited stretch-induced quadriceps spasticity. Spasticity was quantified using the pendulum test before and at two time points after (immediate, 45 min delayed) each of four different physical therapeutic/electroceutic interventions, plus a sham-control intervention. Interventions included stretching, cyclic passive movement (CPM), transcutaneous spinal cord stimulation (tcSCS), and transcranial direct current stimulation (tDCS). The sham-control intervention consisted of a brief ramp-up and ramp-down of knee and ankle stimulation while reclined with legs extended. The order of interventions was randomized, and each was tested on a separate day with at least 48 h between sessions. Compared to the sham-control intervention, stretching, CPM, and tcSCS were associated with a significantly greater reduction in spasticity immediately after treatment. While the immediate effect was largest for stretching, the reduction persisted

  4. Toxic Chemical from Plastics Attenuates Phenylbiguanide-induced Cardio-respiratory Reflexes in Anaesthetized Rats. (United States)

    Pant, Jayanti; Pant, Mahendra K; Chouhan, Shikha; Singh, Surya P; Deshpande, Shripad B


    Bisphenol A (BPA) attenuated phenylbiguanide (PBG)-induced cardio-respiratory reflexes involving decreased vagal afferent activity. BPA leaches out from plastics thus it is expected that chronic exposure to plastic boiled (PBW) water will also produce similar changes. Therefore, the present study was undertaken to evaluate the effects of chronic ingestion of PBW on PBG evoked reflexes and were compared with BPA. Adult female rats were ingested BPA containing pellets (2 µg/kg body weight)/PBW/tap water (ad libitum) for 30 days. On day 30, the animals were anaesthetized and BP, ECG and respiratory excursions were recorded. Further, PBG was injected intravenously to evoke cardio-respiratory reflexes and at the end lungs were excised for histopathological examination. BPA concentration in PBW was 6.6 µg/ml estimated by HPLC. In rats receiving tap water, PBG produced bradycardia, hypotension and tachypnoea. In PBW/BPA treated groups, PBG-induced reflexes were attenuated significantly along with emphysematous and consolidative changes in lungs. The present results indicate that PBW attenuates the protective cardio-respiratory reflexes and also produces histopathological changes in lungs.

  5. Effect of breathing 7% carbon dioxide on the human soleus Hoffmann-reflex recruitment curve. (United States)

    Maloney, Brian J; Beekley, Matthew D


    To examine the effect of inhaling 7% carbon dioxide on the recruitment curve of the soleus H-reflex. Five males and five females (apparently healthy; 21-40 yr) with surface EMG electrodes over the soleus muscle randomly breathed room air or a 7% CO₂, 21% O₂, balance N₂ mix for 10 min. The tibial nerve was stimulated to elicit the H-reflex recruitment curve. H-reflex threshold, motor threshold, slope of ascending H-reflex curve, Hmax:Mmax ratio, and latency of Hmax were compared. Breathing 7% carbon dioxide increased the H-reflex threshold (as a percent of motor threshold) from 73% (SD 0.09) to 84% (SD 0.12; p0.05), Mmax (room air: 3.70 mV (SD 1.57); CO₂: 3.69 mV (SD 1.53); p>0.05), and motor threshold (p>0.05) remained unchanged. Breathing 7% carbon dioxide reduces afferent synaptic transmission in the soleus muscle by slowing transmission, increasing threshold stimulus, and reducing H wave size. Clinicians and scientists should consider the possibility that carbon dioxide can reduce afferent synaptic transmission. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  6. Plantar reflex excitability is increased in the evening in restless legs syndrome patients. (United States)

    Dafkin, Chloe; Green, Andrew; Olivier, Benita; McKinon, Warrick; Kerr, Samantha


    To investigate if diurnal changes in spinal excitability (plantar reflex) occur in restless legs syndrome (RLS) participants compared to healthy matched controls. Thirteen RLS participants and 13 healthy control participants' plantar reflex responses were evaluated in the evening (PM) and the morning (AM). Plantar reflex responses were assessed electromyographically, using motion analysis (kinematically) and by subjective nociception (Visual Analogue Scale). RLS participants showed a circadian variation in plantar reflex responses whilst control participants did not. Evening ankle angle changes were larger and faster in RLS participants compared to morning responses. In addition RLS participants displayed significantly smaller change in ankle angle and significantly slower ankle movements in the evening and the morning as well as significantly lower lateral gastrocnemius maximum amplitude in the compared to control participants. The findings of the current study support the theory of RLS circadian fluctuations in spinal excitability. An unexpected finding was decreased plantar reflex responses in RLS participants compared to healthy control participants. However this finding supports the theory of mechanical hypoesthesia in RLS. The results of this study provide further insight into the pathophysiology of RLS, highlighting that not all sensory processing is affected in the same manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Improved postural control after slackline training is accompanied by reduced H-reflexes. (United States)

    Keller, M; Pfusterschmied, J; Buchecker, M; Müller, E; Taube, W


    "Slacklining" represents a modern sports activity where people have to keep balance on a tightened ribbon. The first trials on the slackline result in uncontrollable lateral swing of the supporting leg. Training decreases those oscillations and therefore improves postural control. However, the underlying neural mechanisms are not known. Therefore, the present study aimed to highlight spinal adaptations going along with slackline training. Twenty-four subjects were either assigned to a training or a control group and postural control was assessed before and after the 10 training sessions. Additionally, soleus Hoffmann (H)-reflexes were elicited to evaluate changes in the excitability of the spinal reflex circuitry. Trained subjects were able to maintain balance on the slackline for at least 20 s (P<0.001) and reduced platform movements on the balance board (P<0.05). The H-reflexes were significantly diminished (P<0.05) while no changes occurred in the background electromyography (bEMG). The control group showed no significant changes. From a functional point of view the reflex reduction may serve to suppress uncontrollable reflex mediated joint oscillations. As the bEMG remained unchanged, presynaptic rather than post-synaptic mechanisms are speculated to be responsible for the changes in the Ia-afferent transmission. © 2011 John Wiley & Sons A/S.

  8. The effects of prostaglandins E1, F1α and F2α on monosynaptic reflexes (United States)

    Duda, P.; Horton, E. W.; McPherson, Angus


    1. Experiments, using electrophysiological recording techniques, were carried out to confirm the report that prostaglandins affect spinal reflexes in cats. 2. Ventral root potentials evoked by stimulation of the ipsilateral dorsal root were recorded. Those with a latent period corresponding to a monosynaptic pathway were used primarily in this investigation. 3. Prostaglandin E1 (3·5-17·8 μg/kg) injected into the aorta reduced the amplitude of monosynaptic responses in six out of ten cats. The effect began about 15 min after injection and lasted over 3 hr. In one cat E1 caused potentiation of the reflex and in three cats there was no effect. 4. Prostaglandin F1α (2·4-3·5 μg/kg) inhibited the monosynaptic response in four cats but in one of these a subsequent large dose (19·6 μg/kg) greatly potentiated the reflex. 5. Prostaglandin F2α (1·4-17·8 μg/kg) injected into the aorta was followed by significant but variable changes in monosynaptic response. In one experiment an intravenous injection (30·3 μg/kg) was followed by a long-lasting potentiation of the reflex response. 6. It is concluded that prostaglandins, two of which have previously been identified in cat brain extracts, have pronounced and long-lasting effects on monosynaptic spinal reflexes. PMID:5659846

  9. Abnormal reflex activation of hamstring muscles in dogs with cranial cruciate ligament rupture. (United States)

    Hayes, Graham M; Granger, Nicolas; Langley-Hobbs, Sorrel J; Jeffery, Nick D


    The mechanisms underlying cranial cruciate ligament rupture (CCLR) in dogs are poorly understood. In this study hamstring muscle reflexes in response to cranial tibial translation were analysed to determine whether these active stabilisers of the stifle joint are differently activated in dogs with CCLR compared to control dogs. In a prospective clinical study reflex muscle activity from the lateral and medial hamstring muscles (biceps femoris and semimembranosus) was recorded using surface electrodes in control dogs (n=21) and dogs with CCLR (n=22). These electromyographic recordings were analysed using an algorithm previously validated in humans. The hamstring reflex was reliably and reproducibly recorded in normal dogs. Both a short latency response (SLR, 17.6±2.1ms) and a medium latency response (MLR, 37.7±2.7ms) could be identified. In dogs with unilateral CCLR, the SLR and MLR were not significantly different between the affected and the unaffected limbs, but the MLR latency of both affected and unaffected limbs in CCLR dogs were significantly prolonged compared to controls. In conclusion, the hamstring reflex can be recorded in dogs and the MLR is prolonged in dogs with CCLR. Since both affected and unaffected limbs exhibit prolonged MLR, it is possible that abnormal hamstring reflex activation is a mechanism by which progressive CCL damage may occur. The methodology allows for further investigation of the relationship between neuromuscular imbalance and CCLR or limitations in functional recovery following surgical intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. The ubiquitous reflex and its critics in post-revolutionary Russia. (United States)

    Sirotkina, Irina


    In the last century, the reflex was more than a scientific concept: it was a cultural idiom that could be used to various aims--political, scholarly, and artistic. In Russia in the 1920s, the reflex became a ubiquitous notion and a current word, part of the revolutionary discourse and, finally, a password to modernity. Two major factors contributed to it: physiological theories of the reflex, widespread in Russia at the early twentieth-century, and the materialist philosophy backed after the Revolution by the Communist party. Everybody who wished to be modern and materialist, in conformity with the official communist views, had to refer to reflexes. Yet, even in this period, the concept was not unproblematic and was criticized by some scientists, philosophers, artists and even Party members. In the paper, I describe both the array of uses of the term and the criticism it received in political, scientific and artistic discourses. It is not uncommon that, taking their origins in culture and common language, scientific concepts later return there in the form of metaphors. Similarly, the reflex was made into a rigorous scientific concept in the nineteenth century but, in the next century, it circulated as a cultural idiom penetrating various areas of political, artistic and academic life.

  11. Neurophysiologic aspects of patients with generalized or multifocal tonic dystonia of reflex sympathetic dystrophy. (United States)

    van de Beek, Willem-Johan T; Vein, Alla; Hilgevoord, Anthony A J; van Dijk, J Gert; van Hilten, Bob J


    Reflex sympathetic dystrophy (RSD) is a syndrome dominated by sensory, autonomic, and motor features of the extremities. In this study, 10 severely affected RSD patients who progressed to multifocal or generalized tonic dystonia underwent H-reflex evaluation, needle electromyography (EMG), polysomnography, somatosensory evoked potentials, and transcranial magnetic stimulation. H-reflex evaluation revealed an impaired vibratory inhibition of the H-reflex and a higher facilitation peak in the recovery curve between 200 to 350 msec. Needle EMG revealed an impaired reciprocal inhibition, and many patients were unable to alter the amount of muscle activity voluntarily. Evaluations of the stretch reflex showed a markedly decreased threshold and abnormal responses to tonic and phasic changes. Polysomnography performed in five patients revealed no abnormal EMG activity during nonrapid eye movement and rapid eye movement sleep, but EEG arousal phenomena provoked abnormally high and brief bursts of surface EMG activity in all registered muscle groups. Somatosensory evoked potentials and transcranial magnetic stimulation were normal. Taken together, the findings in these patients with tonic dystonia of RSD are in accordance with an impairment of inhibitory interneuronal circuits at the level of the brainstem or spinal cord.

  12. Swedish Massage and Abnormal Reflexes of Children with Spastic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Vida Alizad


    Full Text Available Objectives: Massage therapy is one of the most widely used complementary and alternative medicine therapies for children. This study was conducted to determine the effect of wedish massage on abnormal reflexes in children with spastic cerebral palsy (CP. Methods: This study was a single blind clinical trial conducted on forty children with spastic CP who were recruited from clinics of the University of Social Welfare & Rehabilitation Sciences. They were randomly assigned to intervention and control groups. The routine occupational therapy (OT techniques were performed during a 3 month-period in both groups. The intervention group also received Swedish massage for 30 minutes before every OT session. Primary, spinal, brain stem, midbrain, cortical and automatic reflexes were evaluated at the beginning of the study and 3 months later. The data analysis was done by parametric and nonparametric tests. Results: Finally, thirteen subjects in the intervention group and 14 subjects in the control group were remained and studied. The average ages in the intervention and control groups were 49.5 and 42.1 months respectively. There were no statistically significant differences in abnormal reflexes in the intervention group in comparison to the control (P>0.05. Discussion: Adding Swedish massage to traditional OT techniques had no significant effects on abnormal reflexes in children with spastic cerebral palsy. Evidently more research is required in order to completely reject the effects of Swedish massage on abnormal reflexes of children with CP.

  13. The effects of team reflexivity on psychological well-being in manufacturing teams. (United States)

    Chen, Jingqiu; Bamberger, Peter A; Song, Yifan; Vashdi, Dana R


    While the impact of team reflexivity (a.k.a. after-event-reviews, team debriefs) on team performance has been widely examined, we know little about its implications on other team outcomes such as member well-being. Drawing from prior team reflexivity research, we propose that reflexivity-related team processes reduce demands, and enhance control and support. Given the centrality of these factors to work-based strain, we posit that team reflexivity, by affecting these factors, may have beneficial implications on 3 core dimensions of employee burnout, namely exhaustion, cynicism, and inefficacy (reduced personal accomplishment). Using a sample of 469 unskilled manufacturing workers employed in 73 production teams in a Southern Chinese factory, we implemented a time lagged, quasi-field experiment, with half of the teams trained in and executing an end-of-shift team debriefing, and the other half assigned to a control condition and undergoing periodic postshift team-building exercises. Our findings largely supported our hypotheses, demonstrating that relative to team members assigned to the control condition, those assigned to the reflexivity condition experienced a significant improvement in all 3 burnout dimensions over time. These effects were mediated by control and support (but not demands) and amplified as a function of team longevity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  14. Effects of gamma-aminobutyric acid on the Hering-Breuer inspiration-inhibiting reflex. (United States)

    Aleksandrova, N P; Aleksandrov, V G; Ivanova, T G


    Acute experiments on rats were performed to study the effects of intraventricular microinjections of gamma-aminobutyric acid (GABA) on the volume-time parameters of external respiration and the inspiration-inhibiting Hering-Breuer reflex. The state of this reflex before and after GABA administration was assessed in terms of the extent of changes in the duration and amplitude of inspiratory oscillations in intrathoracic pressure in response to end-expiratory occlusion of the trachea. Administration of 20 microM GABA into the lateral ventricles of the brain decreased the minute ventilation (due to reductions in the respiratory frequency and respiratory volume), weakened respiratory muscle contractions, and decreased the peak airflow rate on inspiration and expiration. The response to end-expiratory occlusion decreased significantly after administration of GABA, demonstrating the involvement of GABAergic mechanisms in mediating the inspiration-inhibiting Hering-Breuer reflex.

  15. Reflexive photography: an alternative method for documenting the learning process of cultural competence. (United States)

    Amerson, Roxanne; Livingston, Wade G


    This qualitative descriptive study used reflexive photography to evaluate the learning process of cultural competence during an international service-learning project in Guatemala. Reflexive photography is an innovative qualitative research technique that examines participants' interactions with their environment through their personal reflections on images that they captured during their experience. A purposive sample of 10 baccalaureate nursing students traveled to Guatemala, where they conducted family and community assessments, engaged in home visits, and provided health education. Data collection involved over 100 photographs and a personal interview with each student. The themes developed from the photographs and interviews provided insight into the activities of an international experience that influence the cognitive, practical, and affective learning of cultural competence. Making home visits and teaching others from a different culture increased students' transcultural self-efficacy. Reflexive photography is a more robust method of self-reflection, especially for visual learners.

  16. Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex (United States)

    Dale, Karl Yngvar; Flaten, Magne Arve; Elden, Åke; Holte, Arne


    A group of persons with dissociative identity disorder (DID) was compared with a group of persons with other dissociative disorders, and a group of nondiagnosed controls with regard to prepulse inhibition (PPI) of the acoustic startle reflex. The findings suggest maladaptive attentional processes at a controlled level, but not at a preattentive automatic level, in persons with DID. The prepulse occupied more controlled attentional resources in the DID group compared with the other two groups. Preattentive automatic processing, on the other hand, was normal in the DID group. Moreover, startle reflexes did not habituate in the DID group. In conclusion, increased PPI and delayed habituation is consistent with increased vigilance in individuals with DID. The present findings of reduced habituation of startle reflexes and increased PPI in persons with DID suggest the operation of a voluntary process that directs attention away from unpleasant or threatening stimuli. Aberrant voluntary attentional processes may thus be a defining characteristic in DID. PMID:18830396

  17. Acoustic Reflex Measurements in Normal, Cochlear, and Retrocochlear Lesions -Part1

    Directory of Open Access Journals (Sweden)

    Navid Shahnaz


    Full Text Available The cut off points of 90th percentile of acoustic reflex thresholds were determined in the normal and sensory hearing loss.All subjects had measurable hearing(ANSI-1969≤110 dBHL in three frequencies of 500,1000 and 2000Hz.While hearing loss was more than 55dB, The cut off point was higher in studies that NR responses was included.In cases that hearing loss was less than 75dB, 90th percentile can be used in diganosis of retrochochlear lesions.Since Acoustic reflexes are absent in both mentioned pathologies in greater amount of hearing loss,It would be less efficient in diffrential diganisis of cochlear and retrochochlear lesions to use acoustic reflex thresholds under the mentioned circumstances.

  18. [Dry immersion effects on the mechanisms of metabolic-reflex regulation of hemodynamics during muscular work]. (United States)

    Bravyĭ, Ia R; Bersenev, E Iu; Missina, S S; Borovik, A S; Sharova, A P; Vinogradova, O L


    Effects of 4-d dry immersion on metabolic-reflex regulation of hemodynamics were evaluated during local static work (30% of maximum voluntary effort) of the talocrural extensors. One group of immersed test-subjects received low-frequency electrostimulation of leg muscles to offset the immersion effect on EMG of working muscles. Metabolic-reflex regulation was evaluated through comparison of cardiovascular responses to physical tests with and w/o post-exercise vascular occlusion. Immersion vaguely increased heart rate and reduced systolic arterial pressure in resting subjects; however, it did not have a distinct effect on arterial pressure and HR during muscular work or metabolic-reflex potentiation of hemodynamic shifts.

  19. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H; Arendt-Nielsen, L; Mosbech, H


    Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen......'s criteria for multiple chemical sensitivity and 15 eczema patients with airway symptoms elicited by odorous chemicals were compared with 29 age-matched, healthy controls. We measured C5--the capsaicin concentration causing five coughs or more--using the single breath inhalation test. No difference was found...

  20. The joint discourse 'reflexive sustainable development'. From weak towards strong sustainable development

    International Nuclear Information System (INIS)

    Nilsen, Heidi Rapp


    The purpose of this paper is to contribute towards moving the predominant situation of weak sustainable development (WSD) in the direction of strong sustainable development (SSD). More people - academics, politicians, bureaucrats and laymen alike - need to recognize SSD as an alternative to WSD. A joint discourse of WSD and SSD is suggested, called reflexive sustainable development. Here, advocates of WSD and SSD must argue for each specific case why their solution is better. This will expose, amongst other things, the ethical foundations which form part of resulting policy advice. Reflexive sustainable development is to be framed in discourse ethics, thereby remedying the power imbalance and allowing for substantial discussion. Reflexive sustainable development builds on a common theoretical base but will not lead to consensus in all matters. A family metaphor is introduced to inspire a discourse of both consensus and compromise. (author)

  1. Normal tendon reflexes despite absent sensory nerve action potentials in CANVAS: a neurophysiological study. (United States)

    Burke, David; Michael Halmagyi, G


    CANVAS is a recently defined progressive ataxic syndrome with impairment of vestibular, somatosensory and cerebellar function due to atrophic degeneration of dorsal root ganglia and dorsal columns, of cranial nerve somatosensory ganglia, of vestibular ganglia and vestibular nerves and of cerebellar Purkinje cells. While all patients eventually develop sensory impairment in a non-length dependent pattern and lose sensory nerve action potentials, some retain their tendon reflexes. Here we study 5 CANVAS patients with absent sensory nerve action potentials but intact, even brisk Achilles tendon reflexes and, in 4, preserved H reflexes in the upper and lower limbs. These findings imply that dorsal root ganglion neurons subserving cutaneous afferents more vulnerable than those subserving muscle afferents. Our findings have a clinical message: preservation of the Achilles tendon jerk does not exclude a large fibre peripheral neuronopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H.; Arendt-Nielsen, Lars; Mosbech, H.


    between groups in age, body mass index or pulmonary function. The median C5 were 129 micromol/L (control group), 48 micromol/L (multiple chemical sensitivity patients), 32 micromol/L (eczema patients). The reporting of lower airway symptoms from odorous chemicals was significantly (p......Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen...

  3. [The circulation of reflexes in brain research, art and technology. Introductory remarks]. (United States)

    Wübben, Yvonne; Vöhringer, Margarete


    The introduction deals with two main issues: First, it focuses on the question why a history of scientific concepts should not be limited to the analysis of scientific texts alone. Secondly, it shows how the history of the reflex concept gains from looking at various fields such as art, literature and brain research. The crucial role the reflex played in 19th and 20th century and the different meanings it adopted allowed us to conclude with Bruno Latour that the distinction between art and science is in itself historical. Thus, the distinction proves to be of little use for the historiography of complex concepts such as the reflex which rarely appear to be purely scientific.

  4. [Experimental testing of Pflüger's reflex hypothesis of menstruation in late 19th century]. (United States)

    Simmer, H H


    Pflüger's hypothesis of a nerve reflex as the cause of menstruation published in 1865 and accepted by many, nonetheless did not lead to experimental investigations for 25 years. According to this hypothesis the nerve reflex starts in the ovary by an increase of the intraovarian pressure by the growing follicles. In 1884 Adolph Kehrer proposed a program to test the nerve reflex, but only in 1890, Cohnstein artificially increased the intraovarian pressure in women by bimanual compression from the outside and the vagina. His results were not convincing. Six years later, Strassmann injected fluids into ovaries of animals and obtained changes in the uterus resembling those of oestrus. His results seemed to verify a prognosis derived from Pflüger's hypothesis. Thus, after a long interval, that hypothesis had become a paradigma. Though reasons can be given for the delay, it is little understood, why experimental testing started so late.

  5. Two Reflexivities in Current Social Science: Remarks on an Absent Debate

    Directory of Open Access Journals (Sweden)

    Andreas Langenohl


    Full Text Available This paper traces and compares two different uses of the category of reflexivity in contemporary methodological debates in the social sciences. While a first use is strongly influenced by the textual turn in cultural anthropology, a second use is aligned with Pierre BOURDIEU's notion of "scientific reflexivity." Whereas the first use postulates an epistemological break with scientific modernity and argues for a perpetual contextualization and interrelation of research results and methods, BOURDIEU defends sociology’s claim of objectivity, which, according to him, can be redeemed through a reflexive objectification of sociological practice. Up to the present these two uses have existed in almost complete isolation from each other. They represent alternating reactions to, and reconstructions and translations of, poststructuralism and postmodernism in the social sciences. URN: urn:nbn:de:0114-fqs090297

  6. Reflexive journaling on emotional research topics: ethical issues for team researchers. (United States)

    Malacrida, Claudia


    Traditional epistemological concerns in qualitative research focus on the effects of researchers' values and emotions on choices of research topics, power relations with research participants, and the influence of researcher standpoints on data collection and analysis. However, the research process also affects the researchers' values, emotions, and standpoints. Drawing on reflexive journal entries of assistant researchers involved in emotionally demanding team research, this article explores issues of emotional fallout for research team members, the implications of hierarchical power imbalances on research teams, and the importance of providing ethical opportunities for reflexive writing about the challenges of doing emotional research. Such reflexive approaches ensure the emotional safety of research team members and foster opportunities for emancipatory consciousness among research team members.

  7. Recreational soccer can improve the reflex response to sudden trunk loading among untrained women

    DEFF Research Database (Denmark)

    Pedersen, Mogens Theisen; Randers, Morten Bredsgaard; Skotte, Jørgen H.


    assignment was blinded to the test personnel. Physical education students organized the training. During 1 hour of soccer training, the total number of sudden moves including sudden loading of the upper body (e.g. turns, stops, throw-ins, headers, and shoulder tackles) was 192 (63). In SO, time elapsed until......A slower reflex response to sudden trunk loading (SL) has been shown to increase future risk of low back injuries in healthy subjects, and specific readiness training can improve the response to SL among healthy subjects. The purpose of the study was to investigate the effect of recreational soccer...... the reflex response to SL. The faster reflex response indicates that soccer training can reduce the risk of low back injuries....

  8. Reflexive modernization at the source: local media coverage of bovine spongiform encephalopathy in rural Alberta. (United States)

    Davidson, Debra J; Bogdan, Eva


    The potential for reflexive modernization is defined by multiple factors, but the acknowledgment of risk is crucial, particularly among social groups that play a key role in risk minimization. This study offers an examination of the role of local media in response to the outbreak of bovine spongiform encephalopathy (BSE) in beef-producing communities in rural Alberta. BSE is one of several global risk issues that reflexive modernization theorists argue have the potential to trigger a transformation toward a critically reflexive society in which such risks are minimized. Content analysis of newspapers in beef-producing regions in Alberta, however, shows how local media framed BSE in a manner that maximized community cohesion and protection of local culture. This selective coverage of BSE in rural Alberta is quite likely to have contributed to, or at least reinforced, support for the current institutional structure of Canadian agriculture in beef-producing regions, through the constriction of discourse.

  9. Cortical and spinal assessment - a comparative study using encephalography and the nociceptive withdrawal reflex

    DEFF Research Database (Denmark)

    Fischer, I W; Gram, M; Hansen, T M


    BACKGROUND: Standardized objective methods to assess the analgesic effects of opioids, enable identification of underlying mechanisms of drug actions in the central nervous system. Opioids may exert their effect on both cortical and spinal levels. In this study actions of morphine at both levels...... solution in randomized order. The electroencephalogram (EEG) was recorded during rest and during immersion of the hand into ice-water. Electrical stimulation of the sole of the foot was used to elicit the nociceptive withdrawal reflex and the reflex amplitude was recorded. RESULTS: Data from thirty...... morphine administration (P>0.05). CONCLUSIONS: Cold pressor EEG and the nociceptive reflex were more sensitive to morphine analgesia than resting EEG and can be used as standardized objective methods to assess opioid effects. However, no correlation between the analgesic effect of morphine on the spinal...

  10. The development of the pupillary light reflex and menace response in neonatal lambs and kids. (United States)

    Raoofi, Afshin; Mirfakhraie, Pejman; Yourdkhani, Sorush


    The aim of this study was to investigate the development of the pupillary light reflex and menace response in neonatal lambs and goat kids. Thirty lambs and 33 kids were assessed daily from birth until the pupillary light reflex and menace response had become established. All animals had a controlled pupillary light reflex within 20 h of birth. Lambs and kids had developed menace responses by 8 ± 3 and 14 ± 2 days, respectively. The Mann-Whitney test revealed a significant difference (P kids developed a menace response. Male kids developed this response significantly (P = 0.006) later than females. There was no sex difference in the menace response in the lambs. Overall, the findings indicated that lambs develop a menace response earlier than kids, and female kids develop this response more rapidly than their male counterparts. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment.

    Directory of Open Access Journals (Sweden)

    Yang Wang

    Full Text Available Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown.To 1 review the evidence for the pupil light reflex being a sensitive method to evaluate parasympathetic dysfunction, 2 review the evidence relating hearing impairment and parasympathetic activity and 3 seek evidence of possible connections between hearing impairment and the pupil light reflex.Literature searches were performed in five electronic databases. All selected articles were categorized into three sections: pupil light reflex and parasympathetic dysfunction, hearing impairment and parasympathetic activity, pupil light reflex and hearing impairment.Thirty-eight articles were included in this review. Among them, 36 articles addressed the pupil light reflex and parasympathetic dysfunction. We summarized the information in these data according to different types of parasympathetic-related diseases. Most of the studies showed a difference on at least one pupil light reflex parameter between patients and healthy controls. Two articles discussed the relationship between hearing impairment and parasympathetic activity. Both studies reported a reduced parasympathetic activity in the hearing impaired groups. The searches identified no results for pupil light reflex and hearing impairment.As the first systematic review of the evidence, our findings suggest that the pupil light reflex is a sensitive tool to assess the presence of parasympathetic dysfunction. Maximum constriction velocity and relative constriction amplitude appear to be the most sensitive parameters. There are only two studies investigating the relationship between parasympathetic activity and hearing

  12. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment. (United States)

    Wang, Yang; Zekveld, Adriana A; Naylor, Graham; Ohlenforst, Barbara; Jansma, Elise P; Lorens, Artur; Lunner, Thomas; Kramer, Sophia E


    Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown. To 1) review the evidence for the pupil light reflex being a sensitive method to evaluate parasympathetic dysfunction, 2) review the evidence relating hearing impairment and parasympathetic activity and 3) seek evidence of possible connections between hearing impairment and the pupil light reflex. Literature searches were performed in five electronic databases. All selected articles were categorized into three sections: pupil light reflex and parasympathetic dysfunction, hearing impairment and parasympathetic activity, pupil light reflex and hearing impairment. Thirty-eight articles were included in this review. Among them, 36 articles addressed the pupil light reflex and parasympathetic dysfunction. We summarized the information in these data according to different types of parasympathetic-related diseases. Most of the studies showed a difference on at least one pupil light reflex parameter between patients and healthy controls. Two articles discussed the relationship between hearing impairment and parasympathetic activity. Both studies reported a reduced parasympathetic activity in the hearing impaired groups. The searches identified no results for pupil light reflex and hearing impairment. As the first systematic review of the evidence, our findings suggest that the pupil light reflex is a sensitive tool to assess the presence of parasympathetic dysfunction. Maximum constriction velocity and relative constriction amplitude appear to be the most sensitive parameters. There are only two studies investigating the relationship between parasympathetic activity and hearing impairment

  13. Associations between prefrontal cortex activation and H-reflex modulation during dual task gait

    Directory of Open Access Journals (Sweden)

    Daan eMeester


    Full Text Available Walking, although a largely automatic process, is controlled by the cortex and the spinal cord; with corrective reflexes modulated through integration of neural signals from central and peripheral inputs at supraspinal level throughout the gait cycle. However the full mechanism is not described. In this study we used an additional cognitive task to interfere with the automatic processing during walking in order to explore the neural mechanisms involved in healthy young adults. Participants were asked to walk on a treadmill at two speeds, both with and without additional cognitive load. We evaluated the impact of speed and cognitive load by analysing activity of the pre-frontal cortex (PFC using functional Near-Infrared Spectroscopy (fNIRS alongside with spinal cord reflex activity measured by soleus H-reflex amplitude and gait changes obtained by using an inertial measuring unit. Repeated measures ANOVA revealed that fNIRS Oxy-Hb concentrations significantly increased in the PFC with dual task (walking while performing a cognitive task compared to a single talk only (walking (p< 0.05. PFC activity was unaffected by increases of walking speed. H-reflex amplitude and gait variables did not change in response to either dual task or increases of walking speed. When walking under additional cognitive load we observed that participants adapted by using greater activity in the PFC, but that this adaption did not detrimentally affect H-reflex amplitude or gait variables. Our findings suggests that in a healthy young population central mechanisms (PFC are activated in response to cognitive loads but that H-reflex activity and gait performance can successfully be maintained. This study provides insight in the mechanisms behind healthy individuals safely performing dual task walking

  14. The comparison of application of two different frequencies of TENS on excitability of Hoffmann reflex

    Directory of Open Access Journals (Sweden)

    Akbari M


    Full Text Available The aim of this investigation is to compare the effect of applying two transcutaneous electrical nerve stimulation (TENS current with different frequencies (2 Hz & 100 Hz on Hoffmann reflex recorded from gastrosoleus muscle of healthy people. Forty female subjects between 20 to 30 years of age were participated in this quasi-experimental design. Twenty of them were exposed to the 100 Hz current and the remaining 20 to 2 Hz current on dermatome S1 root. The excitability of the alpha motoneurone was measured by H-reflex amplitude (peak to peak max/2 before and after the application of the TENS current for 30 minutes. The reflex was recorded and at measured before (TO and after the application of TENS at different times (T1, T% and T10 up to 10 minutes. The mean values were compared by multiple paired T test (alpha=0.00825. The results indicate a considerable decrement in Hoffmann reflex amplitude after application of 100 Hz current in comarison with that of before the application. The effect last for 10 minutes after the TENS application, whereas the application of 2 Hz current results in increment of the Hoffmann reflex amplitude. The 5 and 10 minutes interval test dose not show any significance and the results were attenuated befor 5 minutes. As a conclusion high frequency of TENS (100 Hz has an inhibitory effect on excitability of alpha motor neurone reflex lasting for 10 minutes, while low frequency of TENS (2 Hz has an facilatory effect on the same motoneurone with short lasting effect.

  15. Bisphenol A attenuates phenylbiguanide-induced cardio-respiratory reflexes in anaesthetized rats. (United States)

    Pant, Jayanti; Pant, Mahendra K; Deshpande, Shripad B


    Bisphenol A (BPA), a toxic chemical released from plastics, produces respiratory arrest and hypotension after a latency. The latency was similar to the reflex apnoea induced by the vagal C fibre stimulation. Therefore, the present study was undertaken to examine the effects of chronic and acute exposure to BPA on cardio-respiratory reflexes elicited by phenylbiguanide (PBG). Acute and chronic experiments were performed on adult female rats. In chronic experiments, the animals were ingested with pellets containing BPA (2 μg/kg body weight) or without BPA (time-matched control) for 30 days. Subsequently, the animals were anaesthetized and prepared for recording blood pressure, ECG and respiratory excursions. PBG was injected through jugular vein to evoke reflexes in these animals. In acute experiments, the PBG reflexes were obtained before and after injecting BPA/ethanol. Also vagal afferent activity was recorded in some rats. In time-matched control rats, PBG produced bradycardia, hypotension and tachypnoea over a period of time. The maximal changes were around 50-65%. In BPA treated group, the PBG-induced heart rate and respiratory frequency changes were attenuated significantly. Acute exposure of animals to BPA (35 mg/kg body weight) for 30 min also attenuated the PBG-induced responses significantly. The attenuation of the PBG reflex responses by BPA in acute experiments was associated with decreased vagal afferent activity. The present results indicate that BPA attenuates the protective cardio-respiratory reflexes due to decreased vagal afferent activity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Effects of teeth clenching on the soleus H reflex during lower limb muscle fatigue. (United States)

    Mitsuyama, Akihiro; Takahashi, Toshiyuki; Ueno, Toshiaki


    We assessed whether the soleus H reflex was depressed or facilitated in association with voluntary teeth clenching during muscle fatigue. A total of 13 and 9 healthy adult subjects were instructed to perform right-side tiptoe standing for 5 (TS1) and 10min (TS2) to induce the soleus muscle fatigue. Electromyograms (EMGs) were recorded from the bilateral masseter as well as the right-side soleus muscles. H reflex was evoked using a surface electrode. The isometric muscle strength during plantar flexion was measured. We tested two dental occlusal conditions (1) with maximal voluntary teeth clenching (MVTC) and (2) at mandibular rest position (RP). H reflex was evoked before and after TS1 and TS2. The isometric muscle strength during plantar flexion was measured before and after TS1 and TS2. Mean amplitudes of H reflex with MVTC before and after TS1 were significantly larger than that with RP before and after TS1. The mean peak torque (PT) during isometric plantar flexion was observed significant differences in all subjects. The mean amplitude of H reflex with MVTC before TS2 was significantly larger than that with RP before TS2. No significant difference between RP after TS2 and MVTC after TS2. The mean PT with MVTC before TS2 was significantly larger than that with RP before TS2. There was no significant difference between RP and MVTC after TS2. The present study demonstrated that teeth clenching could facilitate H reflex regardless of the degree of muscle fatigue. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  17. Assessing TMS-induced D and I waves with spinal H-reflexes. (United States)

    Niemann, Niclas; Wiegel, Patrick; Kurz, Alexander; Rothwell, John C; Leukel, Christian


    Transcranial magnetic stimulation (TMS) of motor cortex produces a series of descending volleys known as D (direct) and I (indirect) waves. In the present study, we questioned whether spinal H-reflexes can be used to dissect D waves and early and late I waves from TMS. We therefore probed H-reflex facilitation at arrival times of D and I waves at the spinal level and thereby changed TMS parameters that have previously been shown to have selective effects on evoked D and different I waves. We changed TMS intensity and current direction and applied a double-pulse paradigm known as short-interval intracortical inhibition (SICI). Experiments were conducted in flexor carpi radialis (FCR) in the arm and soleus (SOL) in the leg. There were two major findings: 1) in FCR, H-reflex facilitation showed characteristic modulations with altered TMS parameters that correspond to the changes of evoked D and I waves; and 2) H-reflexes in SOL did not, possibly because of increased interference from other spinal circuits. Therefore, the most significant outcome of this study is that in FCR, H-reflexes combined with TMS seem to be a useful technique to dissect TMS-induced D and I waves. NEW & NOTEWORTHY Questions that relate to corticospinal function in pathophysiology and movement control demand sophisticated techniques to provide information about corticospinal mechanisms. We introduce a noninvasive electrophysiological technique that may be useful in describing such mechanisms in more detail by dissecting D and I waves from transcranial magnetic stimulation (TMS). Based on the combination of spinal H-reflexes and TMS in the flexor carpi radialis muscle, the technique was shown to measure selective effects on D and I waves from changing TMS parameters.

  18. Dependency of human neck reflex responses on the bandwidth of pseudorandom anterior-posterior torso perturbations. (United States)

    Forbes, Patrick A; de Bruijn, Edo; Schouten, Alfred C; van der Helm, Frans C T; Happee, Riender


    The vestibulocollic (VCR) and cervicocollic (CCR) reflexes are essential to stabilize the head-neck system and to deal with unexpected disturbances. This study investigates how neck reflexes contribute to stabilization and modulate with perturbation properties. We hypothesized that VCR and CCR modulate with the bandwidth of the perturbation and that this modulation is maintained across amplitudes and influenced by the eyes being open or closed. Seated subjects were perturbed in an anterior-posterior direction. The perturbations varied in bandwidth from 0.3 Hz to a maximum of 1.2, 2.0, 4.0, and 8.0 Hz, at three amplitudes, and with eyes open and closed. Frequency response functions of head kinematics and neck muscle EMG demonstrated substantial changes with bandwidth and vision and minor changes with amplitude, which through closed-loop identification were attributed to neural (reflexive) modulation. Results suggest that both reflexes were attenuated when perturbations exceeded the system's natural frequency, thereby shifting from a head-in-space to a head-on-trunk stabilization tendency. Additionally, results indicate that reflexive and mechanical stiffness marginally exceed the negative stiffness due to gravity; a stabilization strategy which minimizes effort. With eyes closed, reflexes were attenuated further, presumably due to a reduced ability to discriminate self-motion, driving the system to a head-on-trunk stabilization strategy at the highest bandwidth. We conclude that VCR and CCR modulate with perturbation bandwidth and visual feedback conditions to maintain head-upright posture, but are invariant across amplitude changes.

  19. Ontogeny of mouse vestibulo-ocular reflex following genetic or environmental alteration of gravity sensing.

    Directory of Open Access Journals (Sweden)

    Mathieu Beraneck

    Full Text Available The vestibular organs consist of complementary sensors: the semicircular canals detect rotations while the otoliths detect linear accelerations, including the constant pull of gravity. Several fundamental questions remain on how the vestibular system would develop and/or adapt to prolonged changes in gravity such as during long-term space journey. How do vestibular reflexes develop if the appropriate assembly of otoliths and semi-circular canals is perturbed? The aim of present work was to evaluate the role of gravity sensing during ontogeny of the vestibular system. In otoconia-deficient mice (ied, gravity cannot be sensed and therefore maculo-ocular reflexes (MOR were absent. While canals-related reflexes were present, the ied deficit also led to the abnormal spatial tuning of the horizontal angular canal-related VOR. To identify putative otolith-related critical periods, normal C57Bl/6J mice were subjected to 2G hypergravity by chronic centrifugation during different periods of development or adulthood (Adult-HG and compared to non-centrifuged (control C57Bl/6J mice. Mice exposed to hypergravity during development had completely normal vestibulo-ocular reflexes 6 months after end of centrifugation. Adult-HG mice all displayed major abnormalities in maculo-ocular reflexe one month after return to normal gravity. During the next 5 months, adaptation to normal gravity occurred in half of the individuals. In summary, genetic suppression of gravity sensing indicated that otolith-related signals might be necessary to ensure proper functioning of canal-related vestibular reflexes. On the other hand, exposure to hypergravity during development was not sufficient to modify durably motor behaviour. Hence, 2G centrifugation during development revealed no otolith-specific critical period.

  20. Reversal of functional disorders by aspiration, expiration and cough reflexes and their voluntary counterparts

    Directory of Open Access Journals (Sweden)

    Zoltan eTomori


    Full Text Available Agonal gasping provoked by asphyxia can save ~15% of mammals even from untreated ventricular fibrillation, but it fails to revive infants with sudden infant death syndrome. Our systematic study of airway reflexes in cats and other animals indicated that in addition to cough, there are 2 distinct airway reflexes that may contribute to auto-resuscitation. Gasp- and sniff-like spasmodic inspirations can be elicited by nasopharyngeal stimulation, strongly activating the brainstem generator for inspiration, which is also involved in the control of gasping. This aspiration reflex (AspR is characterized by spasmodic inspiration without subsequent active expiration and can be elicited during agonal gasping, caused by brainstem trans-sections in cats. Stimulation of the larynx can activate the generator for expiration to evoke the expiration reflex, manifesting with prompt expiration without preceding inspiration. Stimulation of the oro-pharynx and lower airways provokes the cough reflex which results from activating of both generators. The powerful potential of the AspR resembling auto-resuscitation by gasping can influence the control mechanisms of vital functions, mediating reversal of various functional disorders.The AspR in cats interrupted hypoxic apnea, laryngo- and bronchospasm, apneusis and even transient asphyxic coma, and can normalize various hypo- and hyper-functional disorders. Introduction of a nasogastric catheter evoked similar spasmodic inspirations in premature infants and interrupted hiccough attacks in adults. Coughing on demand can prevent anaphylactic shock and resuscitate the pertinent subject. Sniff representing nasal inspiratory pressure and maximal inspiratory and expiratory pressures are voluntary counterparts of airway reflexes, and are useful for diagnosis and therapy of various cardio-respiratory and neuromuscular disorders.

  1. The role of acupuncture in controlling the gagging reflex using a review of ten cases. (United States)

    Fiske, J; Dickinson, C


    The gagging reflex is a physiological reaction which safeguards the airway from foreign bodies. In some people this response is exaggerated to the extent that the acceptance/provision of dental treatment is not possible. The aim of this paper is to review the role of acupuncture in controlling gagging as a safe, cheap, quick and relatively non-invasive technique. Ten people agreed to try ear acupuncture to control gagging during dental treatment. Prior to treatment the severity of gagging was assessed. Acupuncture needles were inserted into a specific anti-gagging point on each ear, manipulated briefly and left in situ. Dental treatment was then carried out and the effectiveness of the acupuncture in preventing gagging was assessed. After treatment, the needles were removed and the patient discharged. All acupuncture was carried out by a dentist trained in its use. Four people had a severe gag reflex which made treatment impossible and six had a very severe reflex which made treatment impossible and affected their dental attendance. Ear acupuncture completely controlled the gag reflex in eight cases (23 treatment episodes) and partially controlled the reflex in two cases (two treatment episodes). Dental treatment could be carried out in all cases and at all visits. The cost of materials was 0.2 pounds per person per visit. Additional clinical time was in the order of 2-3 minutes. There were no adverse reactions to the technique and, on all occasions, patients were fit to leave the surgery and travel home unaccompanied. Ear acupuncture was successful in controlling the gag reflex. It is a safe, quick, inexpensive and relatively noninvasive technique. A controlled clinical trial is required to investigate any placebo effect.

  2. Classification of terminal simplicial reflexive d-polytopes with 3d-1 vertices

    DEFF Research Database (Denmark)

    Øbro, Mikkel


    We classify terminal simplicial reflexive d-polytopes with 3d − 1 vertices. They turn out to be smooth Fano d-polytopes. When d is even there is one such polytope up to isomorphism, while there are two when d is uneven.......We classify terminal simplicial reflexive d-polytopes with 3d − 1 vertices. They turn out to be smooth Fano d-polytopes. When d is even there is one such polytope up to isomorphism, while there are two when d is uneven....

  3. Motricidade reflexa na morte cerebral The reflex activity in the brain death

    Directory of Open Access Journals (Sweden)

    Wilson L. Sanvito


    Full Text Available O diagnóstico de morte cerebral está baseado em critérios clínicos, eletrencefalográficos e angiográficos. Do ponto de vista clínico deve ser evidenciado o seguinte quadro: coma profundo, midríase paralítica bilateral, ausência de reação a qualquer estímulo externo, apnéia, arreflexia superficial e profunda. Do ponto de vista eletrencefalográfico são necessários dois registros, separados por um intervalo de 24 horas, evidenciando traçados iselétricos. No presente trabalho são estudados 15 pacientes com morte cerebral comprovada do ponto de vista clínico e eletrencefalográfico. Em 8 pacientes havia persistência de atividade reflexa durante a fase de morte cerebral (reflexos profundos e/ou superficiais. Fenômenos de automatismos medulares também foram verificados em 3 pacientes.The diagnosis of brain death is based in clinical, electroencephalographic and angiographic data. The criteria for diagnosis of brain death are: deep coma with unreceptivity and unresponsiveness, no movements or breathing (the patient's respiration must be maintained artificially, bilateral dilated and fixed pupils, absence of corneal reflexes, no response to caloric test, absence of deep tendon reflexes and of the superficial abdominal and plantar reflexes, isoelectric EEG maintained for twenty-four hours. The purpose of this study was to observe the natural clinical courses of 15 patients with brain death, specially the data concerning the deep and superficial reflexes. From 15 patients fulfilling the criteria of brain death, 8 maintained spinal reflexes up to the time of cardiac arrest; in five of these patients the superficial abdominal reflexes were present and the reflexes of spinal automatism could be elicited. These results show that the absence of deep and superficial reflexes can't be considered as essencial for the diagnosis of brain death.

  4. Increase in H-reflex gain following 1 week of immobilization

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Sørensen, Mie; Nielsen, Jens Bo

    the effect of 1 week of immobilization on transmission in the corticospinal pathway and the central part of the monosynaptic stretch reflex. In ten healthy volunteers the nondominant forearm, hand and fingers were immobilized by a cast for one week. EMG was obtained from m. Flexor Carpi Radialis (FCR) and m...... removal all measurements had returned to preimmobilization levels. These results show that immobilization of only one week duration is associated with reversible adaptive changes in the gain of the central part of the monosynaptic stretch reflex....

  5. A Study on the Effects of Bee Venom Aqua-Acupuncture on Writhing Reflex


    Jeong Sun-Hee; Koh Hyung-kyun; Park Dong-Suk


    Introduction:In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation on effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex Materials and Methods:Pain animal model was used acetic acid method. The changes of writhing reflex of ...

  6. Reflexões sobre a experiência moderna e a liberdade


    Almeida,Leonardo Pinto de


    O presente artigo tem como objetivo analisar a relação entre o advento da experiência moderna e a questão da liberdade, a partir de uma reflexão sobre o acontecimento da morte de Deus. Seguindo as reflexões contidas nas obras de Foucault, Sartre, Sloterdjik, Blanchot, examinamos a especificidade do enunciado nietzscheano da morte de Deus e suas conseqüências para a vida e a experiência moderna. Assim, concluímos que a experiência moderna apontaria para um paradoxo que assinala um movimento qu...

  7. The Cushing Reflex: Oliguria as a Reflection of an Elevated Intracranial Pressure

    Directory of Open Access Journals (Sweden)

    K. Leyssens


    Full Text Available Oliguria is one of the clinical hallmarks of renal failure. The broad differential diagnosis is well known, but a rare cause of oliguria is intracranial hypertension (ICH. The actual knowledge to explain this relationship is scarce. Almost all literature is about animals where authors describe the Cushing reflex in response to ICH. We hypothesize that the Cushing reflex is translated towards the sympathetic nervous system and renin-angiotensin-aldosterone system with a subsequent reduction in medullary blood flow and oliguria. Recently, we were confronted with a patient who had complicated pituitary surgery and displayed multiple times an oliguria while he developed ICH.

  8. Sympathetic reflex dystrophy with hypofixation of technetium 99 m pyrophosphates on bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Doury, P.; Pattin, S. (Hopital d' Instruction des Armees Begin, 94 - Saint-Mande (France)); Granier, R.; Metges, P.J. (Hopital d' Instruction des Armees du Val-de-Grace, 75 - Paris (France))


    A patient with sympathetic reflex dystrophy following injury to the right foot presented fairly typical clinical and radiological signs, though the hot phase was particularly short. Bone scan with technetium 99 m pyrophosphates demonstrated hypofixation, which, though extremely rare, has been previously reported in the published literature. The fact that isotopic bone hypofixation can occur during sympathetic reflex dystrophy should be recognised, as far from constituting an argument against the early diagnosis of this affection, it should enable the organic nature of the disorder to be confirmed, and assist the physician in making an early diagnosis.

  9. How a Simple Ankle Sprain Turned Into Neuropathic Pain: Complex Reflex Sympathetic Dystrophy Versus Erythromelalgia. (United States)

    Lurati, Ann Regina


    A 36-year-old woman sustained a Grade 2 ankle sprain at work. Two days after the injury, the ankle and foot became red and she complained of "intense burning pain." First diagnosed with complex reflex sympathetic dystrophy, the employee was prescribed medications that provided some pain relief; a subsequent temporary nerve block provided additional relief. However, the symptoms returned and she was treated unsuccessfully with surgical sympathectomy. The employee was referred to a neurologist and diagnosed with primary erythromelalgia, a rare pain disorder that can be mistaken as complex reflex sympathetic dystrophy.

  10. Treatment of Reflex sympathetic dystrophy with Bee venom -Using Digital Infrared Thermographic Imaging-

    Directory of Open Access Journals (Sweden)

    Myung-jang Lim


    Full Text Available Objectives : The purpose of this case is to report the patient with Reflex sympathetic dystrophy, who is improved by Bee venom. Method : We treated the patient with Bee venom who was suffering from Reflex sympathetic dystrophy, using Digital Infrared Thermographic Imaging and Verbal Numerical Rating Scale(VNRS to evaluate the therapeutic effects. We compared the temperature of the patient body before and after treatment. Result and Conclusion : We found that Bee venom had excellent outcome to relieve pain, atrophy and ankle joint ROM, and that Bee venom also had clinical effect on hypothermia on the Digital Infrared Thermographic Imaging.

  11. Tactile Reflex Development Through Wing Tsun’s “Sticking Hands” Practice, by Jeff Webb

    Directory of Open Access Journals (Sweden)

    Jeff Webb


    Full Text Available It was the late Bruce Lee who first demonstrated Wing Tsun gongfu’s “sticking hands” (chi-sau exercise in the US, during the 1964 Long Beach International Karate Championships. Forty-four years later, very few outside of the art truly understand the purpose of chi-sau let alone how it develops tactile reflexes. This article will describe both the fundamental and complex methods of chi-sau training in detail. It will also explain the rationale and theories behind this method as well as discuss a variety of factors that can either improve or retard the acquisition of tactile reflexes.

  12. The Use of Restoring Resources of the Survival Roles and Reflex Patterns in MNRI® (Reflex Integration Interactive Training of Personality Growth and Interpersonal Relations

    Directory of Open Access Journals (Sweden)

    Masgutova S.K.


    Full Text Available Personality growth as a socio-psychological problem is a multi-complex phenomenon that targets Self-identity, Self-actualization, and other areas. During the last decade scientists started studying other factors limiting the personality growth, such as stress and post-trauma. However, the Survival Roles, the socio-individual patterns based on neurophysiological and psychological defense mechanisms blocking the personality Self-actualization, social interaction and professional business qualities, are rarely discussed. Thus this study based on Survival Roles may extend the personality growth oriented concepts and therapy modality tools. This study showed a correlation between Survival Role patterns, stress resilience, and survival reflexes (integrative units of the nervous system functions. Comparative data on 464 business professionals from high management jobs (Study Group — n=340, and Control Group — n=124 participated in this research which found 70.9 % (n=329 of the total group was in stress. This stress activated socio-individual Survival Roles and protective reflex patterns which responded with reactivity, over-protection, non-constructive interactions with others and limited business strategies. The MNRI® reflex integrative training used in this study demonstrated improvement of functions of the protective reflex patterns effected positively the survival mechanisms including increased stress resilience, and decreased negative effect of Survival Roles. MNRI® proposes a new paradigm in the realm of personality growth and socio-interpersonal activity, and supports the neurophysiological aspects to optimize the overall quality of life of business professionals from a variety of high management business areas.

  13. Politics, Knowledge and Objectivity in Sociology of Education: A Response to the Case for "Ethical Reflexivity" by Gewirtz and Cribb (United States)

    Abraham, John


    The present article examines the relationship between political values and social research, with particular reference to the case for ethical reflexivity in sociology of education put forward by Gewirtz and Cribb. It is argued that their case for such reflexivity is flawed by conceptual imprecision and over-determination of the links between value…

  14. Relationship between the degree of inhibited stretch reflex activities of the wrist flexor and reaction time during quick extension movements. (United States)

    Kizuka, T; Asami, T; Tanii, K


    It has been reported that stretch reflex responses, including the long latency component, are modulated by motor preparation for the direction and type of movement. In the present study, human subjects were required to make a reaction movement in the direction of the wrist extension following a muscle stretch to the wrist flexor, and we investigated the relationship between the modulation of reflex activities of the wrist flexor and the length of reaction time (premotor time) of the wrist extensor. Twenty-five healthy males, ranging in age from 20 to 28, participated in the experiments. A DC torque motor was used to evoke the reflex EMG responses on the flexor. Averaging the rectified EMG, recorded with the surface electrodes over the flexor, showed short and long latency reflexes (M1 and M2 components) in response to the muscle stretch. For all subjects, the amplitudes of the reflex components during the extension reaction movement decreased, compared to those amplitudes in the non-reaction tasks. The decrease in the M2 component, which is considered a transcortical reflex, was significantly larger than the decrease in the M1 component, which is a spinal reflex. Moreover, there were correlations between reaction time to muscle stretch and the degree of decrease in reflex activities with the extension reaction (r = 0.652 for M1, r = 0.813 for M2, P motor control required to perform quick movements.

  15. Teaching and learning reflexive skills in inter- and transdisciplinary research: A framework and its application in environmental science education

    NARCIS (Netherlands)

    Fortuin, K.P.J.; Koppen, van C.S.A.


    A crucial skill for researchers in inter- and transdisciplinary environmental projects is the ability to be reflexive about knowledge and knowledge production. Few studies exist on the operationalization of reflexive skills and teaching and learning strategies that help students master these skills.

  16. Electromyographic tendon reflex recording: An accurate and comfortable method for diagnosis of charcot-marie-tooth disease type 1a. (United States)

    García, Antonio; Pelayo-Negro, Ana L; Álvarez-Paradelo, Silvia; Antolín, Francisco M; Berciano, José


    We analyzed the utility of tendon reflex (T-reflex) testing in Charcot-Marie-Tooth disease type 1A (CMT1A). A total of 82 subjects from 27 unrelated CMT1A pedigrees were evaluated prospectively. The series also comprised 28 adult healthy controls. Electrophysiology included evaluation of biceps T-reflex and soleus T-reflex. Seventy-one individuals (62 adults and 9 children) had clinical and electrophysiological features of CMT1A. The remaining 11 (8 adults and 3 children) were unaffected. On electrophysiological testing, the biceps T-reflex was elicited in 58 of 62 (93%) adult CMT1A patients and in all 9 affected children. Latencies of the biceps T-reflex were always markedly prolonged, and a cut-off limit of 16.25 ms clearly separated adult patients and controls or unaffected kin adult individuals. In affected children, the soleus T-reflex latency was also prolonged when compared with age and height normative data. T-reflex testing is an accurate diagnostic technique for CMT1A patients. © 2014 Wiley Periodicals, Inc.

  17. Effect of pelvic floor muscle contraction on vesical and rectal function with identification of puborectalis-rectovesical inhibitory reflex and levator-rectovesical excitatory reflex. (United States)

    Shafik, A; El-Sibai, O


    changes. Repetition of the test using saline instead of xylocaine resulted in rectal and vesical pressure responses similar to those without the use of saline. In conclusion, the decline in rectal and vesical responses upon PR muscle contraction indicates a reflex relationship which we term 'puborectalis rectovesical inhibitory reflex'. This reflex is suggested to abort the urge to defecate or urinate. In contrast, LA muscle contraction produced rectal and vesical pressure elevation which is suggested to be mediated through the 'levator rectovesical excitatory reflex'. 'This reflex is probably evoked to promote rectal and vesical evacuation.

  18. Autoethnography as a Method for Reflexive Research and Practice in Vocational Psychology (United States)

    McIlveen, Peter


    This paper overviews the qualitative research method of autoethnography and its relevance to research in vocational psychology and practice in career development. Autoethnography is a reflexive means by which the researcher-practitioner consciously embeds himself or herself in theory and practice, and by way of intimate autobiographic account,…

  19. The Only Honest Thing: Autoethnography, Reflexivity and Small Crises in Fieldwork (United States)

    Delamont, Sara


    There has been a rising acceptance of autoethnography in the past 15 years. Instead of studying social phenomena, in an appropriately reflexive way, some scholars have taken to researching themselves. Drawing on concrete examples from an ongoing ethnographic project, the paper contrasts the beneficial, even essential, practices of autobiographical…

  20. Evolutionary transition from biological to social systems via generation of reflexive models of externality. (United States)

    Igamberdiev, Abir U


    Evolutionary transition from biological to social systems corresponds to the emergence of the structure of subject that incorporates the internal image of the external world. This structure, established on the basis of referral of the subject (self) to its symbolic image, acquires a potential to rationally describe the external world through the semiotic structure of human language. It has been modelled in reflexive psychology using the algebra of simple relations (Lefebvre, V.A., J. Soc. Biol. Struct. 10, 129-175, 1987). The model introduces a substantial opposition of the two basic complementary types of reflexion defined as Western (W) and Eastern (E). These types generate opposite models of behavior and opposite organizations of societies. Development of human societies involves the interactions of W and E types not only between the societies but also within one society underlying its homeostasis and dynamics. Invention of new ideas and implementation of new technologies shift the probability pattern of reflexive choices, appearing as internal assessments of the individual agents within a society, and direct changes in the preference of reflexive types. The dynamics of societies and of interactions between societies is based on the interference of opposite reflexive structures and on the establishment of different patterns during such interference. At different times in the history of human civilization these changing patterns resulted in the formation and splitting of large empires, the development and spreading of new technologies, the consecutive periods of wellness and decline. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Reflexivity and Transnational Habitus: The Case of a "Poor" Affluent Chinese International Student (United States)

    De Costa, Peter I.; Tigchelaar, Magda; Cui, Yaqiong


    Following Sayer's (2010) examination of reflexivity and habitus, we focus on the "transnational habitus" (Darvin & Norton 2015) of Aaron, a Chinese international student at a U.S. university. Specifically, we examine how he wrestled with being identified as an ESL learner despite having attended a U.S. high school. Also exploring the…

  2. Extension of Kirk-Saliga Fixed Point Theorem in a Metric Space with a Reflexive Digraph

    Directory of Open Access Journals (Sweden)

    Karim Chaira


    Full Text Available We extend the result of Kirk-Saliga and we generalize Alfuraidan and Khamsi theorem for reflexive graphs. As a consequence, we obtain the ordered version of Caristi’s fixed point theorem. Some concrete examples are given to support the obtained results.

  3. The relationship between nociceptive brain activity, spinal reflex withdrawal and behaviour in newborn infants (United States)

    Hartley, Caroline; Goksan, Sezgi; Poorun, Ravi; Brotherhood, Kelly; Mellado, Gabriela Schmidt; Moultrie, Fiona; Rogers, Richard; Adams, Eleri; Slater, Rebeccah


    Measuring infant pain is complicated by their inability to describe the experience. While nociceptive brain activity, reflex withdrawal and facial grimacing have been characterised, the relationship between these activity patterns has not been examined. As cortical and spinally mediated activity is developmentally regulated, it cannot be assumed that they are predictive of one another in the immature nervous system. Here, using a new experimental paradigm, we characterise the nociceptive-specific brain activity, spinal reflex withdrawal and behavioural activity following graded intensity noxious stimulation and clinical heel lancing in 30 term infants. We show that nociceptive-specific brain activity and nociceptive reflex withdrawal are graded with stimulus intensity (p < 0.001), significantly correlated (r = 0.53, p = 0.001) and elicited at an intensity that does not evoke changes in clinical pain scores (p = 0.55). The strong correlation between reflex withdrawal and nociceptive brain activity suggests that movement of the limb away from a noxious stimulus is a sensitive indication of nociceptive brain activity in term infants. This could underpin the development of new clinical pain assessment measures. PMID:26228435

  4. Manual therapy directed at the knee or lumbopelvic region does not influence quadriceps spinal reflex excitability


    Grindstaff, Terry L; Pietrosimone, Brian G; Sauer, Lindsay D; Kerrigan, D. Casey; Patrie, James T; Hertel, Jay; Ingersoll, Christopher D


    Manual therapies, directed to the knee and lumbopelvic region, have demonstrated the ability to improve neuromuscular quadriceps function in individuals with knee pathology. It remains unknown if manual therapies may alter impaired spinal reflex excitability, thus identifying a potential mechanism in which manual therapy may improve neuromuscular function following knee injury.

  5. The amplitude of the Achilles tendon reflex in infants is related to body position

    NARCIS (Netherlands)

    Bruggink, Janneke L. M.; Bos, Arend F.; vd Hoeven, Johannes H.; Brouwer, Oebele F.; Sollie, Krystyna M.; Sival, Deborah A.


    In this study, we investigated whether the Achilles tendon reflex (ATR) in healthy infants is modulated by changes in body position (prone vs. supine). The amplitude of the ATR was compared at postnatal day 1, months 2, 3 and 6, while infants were placed in prone and supine position. The ATR was

  6. Team innovation and effectiveness: the importance of minority dissent and reflexivity

    NARCIS (Netherlands)

    de Dreu, C.K.W.


    Past research suggests that minority dissent in teams may foster team innovations. It is hypothesized, however, that minority dissent would predict team innovations only when teams have high levels of reflexivity?the tendency to overtly reflect upon the group's objectives, strategies, and processes

  7. Structural Unemployment and Its Effects: There Is Always a Reflexive Response (United States)

    Winslade, John


    A poststructuralist perspective on unemployment is discussed to include a reflexive interplay between harsh economic "realities" and conscious decision-making. Through an example of an individual story it is argued that objective economic knowledge is often complicated by what people do with it. In this case the dominant economic discourse had…

  8. Using Stimulation of the Diving Reflex in Humans to Teach Integrative Physiology (United States)

    Choate, Julia K.; Denton, Kate M.; Evans, Roger G.; Hodgson, Yvonne


    During underwater submersion, the body responds by conserving O[subscript 2] and prioritizing blood flow to the brain and heart. These physiological adjustments, which involve the nervous, cardiovascular, and respiratory systems, are known as the diving response and provide an ideal example of integrative physiology. The diving reflex can be…

  9. Baro–Reflex Sensitivity is Augmented more in Athletes than in Sickle ...

    African Journals Online (AJOL)

    This study examined the effect of chronic, low dose vitamin C supplementation on the baro-reflex sensitivity (BRS), rate - pressure product (RPP) and Barach energy index (BEI) in 21 male athletes and sickle cell anaemia subjects (SCAS). Arterial blood pressure and heart rate were recorded in the supine position and ...

  10. Artificial-reflex stimulation for FES-induced standing with minimum quadriceps force

    NARCIS (Netherlands)

    Mulder, A.J.; Mulder, A.J.; Boom, H.B.K.; Hermens, Hermanus J.; Zilvold, G.; Zilvold, G.


    A control strategy is proposed to decrease quadriceps activity during standing. Modified on/off (or artificial reflex) control is used: a non-numerical or finite-state control scheme based on feedback of knee angle and angular velocity. The control strategy is evaluated in paraplegic patients in an

  11. Preschoolers' Comprehension of Pronouns and Reflexives: The Impact of the Task (United States)

    Bergmann, Christina; Paulus, Markus; Fikkert, Paula


    Pronouns seem to be acquired in an asymmetrical way, where children confuse the meaning of pronouns with reflexives up to the age of six, but not vice versa. Children's production of the same referential expressions is appropriate at the age of four. However, response-based tasks, the usual means to investigate child language comprehension, are…

  12. For reflexivity as an epistemic criterion of ontological coherence and virtuous social theorizing (United States)


    This article offers an approach that combines, on the one hand, the philosophical notion of reflexivity, which is related to the ideas of self-reference and paradox, and, on the other hand, the sociological discussion of epistemic reflexivity as a problem of coherence, which was mainly initiated by certain branches of ethnomethodology and social constructionism. This combinatory approach argues for reflexivity as an epistemic criterion of ontological coherence, which suggests that social ontologies should account for the possibility of self-reflective subjectivity – for otherwise they result in a paradoxical conclusion according to which a social scientist reflects on her or his ontological commitments even though these commitments deny her or him the capacity for self-reflection. This analysis presupposes that all human sciences are categorically premised on social ontologies; and it argues for an analytical distinction between self-reflection, which refers to the agential capacity for reflecting on one’s own commitments, and the epistemic criterion of reflexivity hereby proposed. These two analytically distinct though interdependent socio-theoretical concepts are frequently conflated in the literature; thus, this article also aims at a ‘clearing of the ground’ that can be of categorical use to the human sciences. PMID:29276343

  13. Blind Evaluation of Body Reflexes and Motor Skills in Learning Disability. (United States)

    Freides, David; And Others


    Twelve 6 to 10 year old boys with learning disability were blindly compared with paired controls on measures of postural and equilibrium reflexes as well as skills. Learning disabled children as a group showed significant deficits on all measures; a few, however, were totally without deficit. (Author/SBH)

  14. How Are Task Reflexivity and Intercultural Sensitivity Related to the Academic Performance of MBA Students? (United States)

    Lyubovnikova, Joanne; Napiersky, Uwe; Vlachopoulos, Panos


    Higher education in business school environments is increasingly focused on how to best equip students with the skills necessary for leadership in the global workplace. This paper examines the impact of two particularly important cognitive capabilities--task reflexivity and intercultural sensitivity, on academic performance in an MBA programme. It…

  15. Influence of Stimulation Location and Posture on the Reliability and Comfort of the Nociceptive Flexion Reflex

    Directory of Open Access Journals (Sweden)

    Gwyn N Lewis


    Full Text Available BACKGROUND: The lower limb nociceptive flexion reflex (NFR is commonly used to assess the function of the nociceptive system. Currently, there is a lack of standardized stimulation procedures to determine the NFR threshold, making comparisons of thresholds across studies difficult.

  16. High levels of sound pressure: acoustic reflex thresholds and auditory complaints of workers with noise exposure

    Directory of Open Access Journals (Sweden)

    Alexandre Scalli Mathias Duarte


    Full Text Available INTRODUCTION: The clinical evaluation of subjects with occupational noise exposure has been difficult due to the discrepancy between auditory complaints and auditory test results. This study aimed to evaluate the contralateral acoustic reflex thresholds of workers exposed to high levels of noise, and to compare these results to the subjects' auditory complaints.METHODS: This clinical retrospective study evaluated 364 workers between 1998 and 2005; their contralateral acoustic reflexes were compared to auditory complaints, age, and noise exposure time by chi-squared, Fisher's, and Spearman's tests.RESULTS: The workers' age ranged from 18 to 50 years (mean = 39.6, and noise exposure time from one to 38 years (mean = 17.3. We found that 15.1% (55 of the workers had bilateral hearing loss, 38.5% (140 had bilateral tinnitus, 52.8% (192 had abnormal sensitivity to loud sounds, and 47.2% (172 had speech recognition impairment. The variables hearing loss, speech recognition impairment, tinnitus, age group, and noise exposure time did not show relationship with acoustic reflex thresholds; however, all complaints demonstrated a statistically significant relationship with Metz recruitment at 3000 and 4000 Hz bilaterally.CONCLUSION: There was no significance relationship between auditory complaints and acoustic reflexes.

  17. Oculocardiac reflex in a dog caused by a choroidal melanoma with orbital extension. (United States)

    Steinmetz, Andrea; Ellenberger, Kristin; März, Imke; Ludewig, Eberhard; Oechtering, Gerhard


    A 7 yr old mixed-breed dog was presented with a choroidal melanoma of the left eye that had penetrated the sclera, producing an orbital mass. Bradycardia was detected on auscultation. The bradycardia resolved after exenteration of the orbit and was therefore presumed to be associated with the oculocardiac reflex.

  18. Prepulse inhibition of the acoustic startle reflex in pigs and its disruption by D-amphetamine

    DEFF Research Database (Denmark)

    Lind, N. M.; Arnfred, S. M.; Hemmingsen, R. P.


    Prepulse inhibition (PPI) of the startle reflex is an operational measure of sensorimotor gating. The dopamine receptor agonist-mediated disruption of PPI in rats is widely used as a model of the sensorimotor gating deficiencies demonstrated in schizophrenia patients. As a possible tool for valid...

  19. An Existentialist in Iqaluit: Existentialism and Reflexivity Informing Pedagogy in the Canadian North (United States)

    Yue, Anthony R.


    Reflecting on the personal experience of teaching human resource management in the Canadian Arctic, the author explores the utility of an existentialist approach to pedagogy. The author outlines select aspects of existentialism that are pertinent to the teaching and discusses the implications of using reflexive existential thought as guidance in a…

  20. The Inter-Reflexive Possibilities of Dual Observations: An Account from and through Experience (United States)

    Barrett, Margaret S.; Mills, Janet


    In this article, we explore the methodological possibilities of dual observation and "inter-reflexive" interpretation as we have experienced this in a longitudinal ethnographic case study of music teaching and learning in an English cathedral choir school. Our intent here is to understand the ways in which our particular historical,…

  1. Corticohypothalamic relationships during the development and realization of the conditioned reflex. (United States)

    Simonov, P V


    The influence of motivational, emotiogenically positive and emotiogenically negative structures of the hypothalamus on the development and realization of conditioned reflexes was investigated in the experiments on dogs, cats, and rats. It was shown that the motivational structures primarily increase excitability of cortical neurons during the development of the conditioned connection, while the emotiogenically negative and emotiogenically positive structures increase the efficiency of synapses. A high degree of correlatedness of the averaged evoked responses to the conditional stimulus in the hypothalamus and new cortex is characteristic for the consolidated conditioned reflex. Direct stimulation of the motivational-alimentary zones of the hypothalamus reproduce food-procuring conditioned reflexes in dogs, while stimulations of the emotiogenically negative zones reproduce defense conditioned reflexes. Stimulation of the emotiogenically positive zones does not reproduce either; however, an intensification of the activity of neurons of the hypothalamus was recorded in rats during the successful accomplishment of the conditioned reaction of avoidance of an aversive stimulus. In cats which are capable of restraining a conditioned motoric reaction for the sake of obtaining a preferred food, the "motivational", long-latency functional connections between neurons of the lateral hypothalamus and the prefrontal cortex predominate. Short-latency "informational" connections predominate in the "impulsive" cats.

  2. Does diurnal variation in cough reflex testing exist in healthy young adults? (United States)

    Perry, Sarah; Huckabee, Maggie-Lee


    The aim of this study was to investigate whether diurnal variation in cough reflex sensitivity exists in healthy young adults when a tidal-breathing method is used. Fifty-three participants (19-37 years) underwent cough reflex testing on two occasions: once in the morning (between 9 am - midday) and once in the afternoon (between 2-5 pm). The order of testing was counter-balanced. Within each assessment, participants inhaled successively higher citric acid concentrations via a facemask, with saline solution randomly interspersed to control for a placebo response. The lowest concentration that elicited a reflexive cough response was recorded. Morning cough thresholds (mean=0.6mol/L) were not different from afternoon cough thresholds (mean=0.6mol/L), p=0.16, T=101, r=-0.14. We found no evidence of diurnal variability in cough reflex testing. There was, however, an order effect irrespective of time of day, confirming that healthy participants are able to volitionally modulate their cough response. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Whole-body vibration induces distinct reflex patterns in human soleus muscle. (United States)

    Karacan, Ilhan; Cidem, Muharrem; Cidem, Mehmet; Türker, Kemal S


    The neuronal mechanisms underlying whole body vibration (WBV)-induced muscular reflex (WBV-IMR) are not well understood. To define a possible pathway for WBV-IMR, this study investigated the effects of WBV amplitude on WBV-IMR latency by surface electromyography analysis of the soleus muscle in human adult volunteers. The tendon (T) reflex was also induced to evaluate the level of presynaptic Ia inhibition during WBV. WBV-IMR latency was shorter when induced by low- as compared to medium- or high-amplitude WBV (33.9±5.3msvs. 43.8±3.6 and 44.1±4.2ms, respectively). There was no difference in latencies between T-reflex elicited before WBV (33.8±2.4ms) and WBV-IMR induced by low-amplitude WBV. Presynaptic Ia inhibition was absent during low-amplitude WBV but was present during medium- and high-amplitude WBV. Consequently, WBV induces short- or long-latency reflexes depending on the vibration amplitude. During low-amplitude WBV, muscle spindle activation may induce the short- but not the long-latency WBV-IMR. Furthermore, unlike the higher amplitude WBV, low-amplitude WBV does not induce presynaptic inhibition at the Ia synaptic terminals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Reflex cough PEF as a predictor of successful extubation in neurological patients* (United States)

    Kutchak, Fernanda Machado; Debesaitys, Andressa Maciel; Rieder, Marcelo de Mello; Meneguzzi, Carla; Skueresky, Amanda Soares; Alberto, Luiz; Bianchin, Marino Muxfeldt


    Abstract Objective: To evaluate the use of reflex cough PEF as a predictor of successful extubation in neurological patients who were candidates for weaning from mechanical ventilation. Methods: This was a cross-sectional study of 135 patients receiving mechanical ventilation for more than 24 h in the ICU of Cristo Redentor Hospital, in the city of Porto Alegre, Brazil. Reflex cough PEF, the rapid shallow breathing index, MIP, and MEP were measured, as were ventilatory, hemodynamic, and clinical parameters. Results: The mean age of the patients was 47.8 ± 17 years. The extubation failure rate was 33.3%. A reflex cough PEF of < 80 L/min showed a relative risk of 3.6 (95% CI: 2.0-6.7), and the final Glasgow Coma Scale score showed a relative risk of 0.64 (95% CI: 0.51-0.83). For every 1-point increase in a Glasgow Coma Scale score of 8, there was a 36% reduction in the risk of extubation failure. Conclusions: Reflex cough PEF and the Glasgow Coma Scale score are independent predictors of extubation failure in neurological patients admitted to the ICU. PMID:26398756

  5. Pain sensation and nociceptive reflex excitability in surgical patients and human volunteers

    DEFF Research Database (Denmark)

    Dahl, J B; Erichsen, C J; Fuglsang-Frederiksen, A


    Pain threshold, nociceptive flexion reflex (NFR) threshold and responses to suprathreshold stimulation were investigated in 15 female patients (mean age 32 yr (range 22-48 yr)) before and 68 (range 48-96) h after gynaecological laparotomy. Control measurements were performed in 17 healthy human v...

  6. Self-reflexivity in gender research: The dilemma of an African ...

    African Journals Online (AJOL)

    This article emanates from my reflections as an African feminist scholar, based on the dilemma that I was confronted with while interpreting my findings from a research on the complexities of socio-cultural constructions of psychological wellbeing and gender roles in farm-families. From a researcher's reflexivity's perspective, ...

  7. Changes in the soleus stretch reflex at different pedaling frequencies and crank loads during pedaling

    DEFF Research Database (Denmark)

    Larsen, Birgit; Voigt, Michael; Grey, Michael James


    The influence of pedaling frequency and crank load on the sensitivity of the soleus short latency stretch reflex (SLR) was examined in nine healthy subjects during pedaling by the use of a custom-built robotic actuator. The SLR decreased successively in downstroke when pedaling frequency increased...

  8. Muscular reflexes elicited by electrical stimulation of the anterior cruciate ligament in humans

    DEFF Research Database (Denmark)

    Dyhre-Poulsen, P; Krogsgaard, M R


    Anterior cruciate ligament (ACL)-deficient knees have impaired proprioception, and, although mechanoreceptors have been found in the ACL, the existence of a reflex elicited from these receptors has not been directly demonstrated in humans. In eight patients that underwent knee arthroscopy and had...

  9. Ironic effects as reflexive responses: Evidence from word frequency effects on involuntary subvocalizations. (United States)

    Bhangal, Sabrina; Merrick, Christina; Morsella, Ezequiel


    In ironic processing, one is more likely to think about something (e.g., white bears) when instructed to not think about that thing. To further investigate this phenomenon involving cognitive control, in the Reflexive Imagery Task (RIT), participants are instructed to not subvocalize the names of visual objects. On the majority of the trials, participants fail to suppress such subvocalizations. This finding supports theorizing that conscious thoughts can be triggered by external stimuli in a manner that is nontrivial, involuntary, and, importantly, reflex-like. These conclusions challenge intuitions that consciousness is unpredictable, whimsical, and somewhat insulated from external control. Perhaps these thoughts arise, not in a reflex-like manner, but from experimental demand or other high-level, strategic processes. This prevalent criticism would be inconsistent with the observation that the RIT effect is influenced by a stimulus parameter such as word frequency. Regarding demand characteristics, such an artifact would require participants to have a theory regarding how word frequency should influence responses. We introduce evidence that stimuli associated with high frequency names are more likely to yield involuntary subvocalizations than stimuli associated with low frequency names. These theoretically-relevant data suggest that ironic effects in paradigms such as the RIT resemble reflex-like processes. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Reflexivity and Self-Care for Creative Facilitators: Stepping outside the Circle (United States)

    Moffatt, Amanda; Ryan, Mary; Barton, Georgina


    Those who work with others to explore new and creative ways of thinking about community and organizational participation, ways of engaging with others, individual well-being and creative solutions to problems, have a significant role in a cohesive society. Creative forms of learning can stimulate reflexive practices of self-care and lead to…

  11. Reflexivity and the "Acting Subject": Conceptualizing the Unit of Analysis in Qualitative Health Research. (United States)

    Shaw, James A


    The ways in which social scientists conceptualize the "reflexive" human subject have important consequences for how we go about our research. Whether and how we understand human subjects to be the authors of our own actions helps to structure what we say about health, health care, and the many other topics addressed in qualitative health research. In this article, I critically discuss assumptions of human reflexivity that are built into qualitative social science of health and medicine. I describe three alternative ways of understanding reflexive thought and human action derived from the theoretical works of Pierre Bourdieu, Bruno Latour, and George Lakoff and Mark Johnson, respectively. I then apply these three different ways of thinking about reflexivity and the acting subject to the analysis of an excerpt of participant observation data from a health services research study of transitions from hospital to home, illuminating the different kinds of analyses that arise from each perspective. I conclude with a call for social scientists to commit to the search for better ways of understanding the human subject, resisting the temptation to "settle" on theoretical statements that close down the path to more sophisticated conceptualizations of human thought and action. © The Author(s) 2016.

  12. Conscious thoughts from reflex-like processes: a new experimental paradigm for consciousness research. (United States)

    Allen, Allison K; Wilkins, Kevin; Gazzaley, Adam; Morsella, Ezequiel


    The contents of our conscious mind can seem unpredictable, whimsical, and free from external control. When instructed to attend to a stimulus in a work setting, for example, one might find oneself thinking about household chores. Conscious content thus appears different in nature from reflex action. Under the appropriate conditions, reflexes occur predictably, reliably, and via external control. Despite these intuitions, theorists have proposed that, under certain conditions, conscious content resembles reflexes and arises reliably via external control. We introduce the Reflexive Imagery Task, a paradigm in which, as a function of external control, conscious content is triggered reliably and unintentionally: When instructed to not subvocalize the name of a stimulus object, participants reliably failed to suppress the set-related imagery. This stimulus-elicited content is considered 'high-level' content and, in terms of stages of processing, occurs late in the processing stream. We discuss the implications of this paradigm for consciousness research. Copyright © 2013 Elsevier Inc. All rights reserved.


    Directory of Open Access Journals (Sweden)



    Full Text Available Introduction. Electrodiagnostic tests are one of the ancillary procedures that are used for diagnosis of multiple sclerosis (MS. This study investigates the frequency of abnormal blink reflex in patients with MS. Methods. In this cross sectional diagnostic study, 100 patients (26 male and 74 female with definite MS were selected based on clinical and MRI findings. they were referred to Al- zahra hospital (affiliated to iUMSHS during year 2000. Blink reflex (BR waves including R1, R2, R2 were recorded inpatients through the stimulation of supraorbital nerve. Results. The frequency of abnormal BR in MS patients with brain stem involvement was 77.9 percent and in those without brain stem involvement was 36.6 percent (P < 0.001. There was a significant relationship between the duration of MS and the abnormality in BR. Discussion. The frequency of abnormal blink reflex in MS is significantly associated with site of involvement in the brain. The majority of MS patients with brain stem involvement have abnormal BR. It is proposed that in patients with symptoms and signs of MS if there was no accessibility for MRI or if the results of MRI were equivocal, blink reflex test should be performed in addition to other ancillary tests.

  14. Reflexivity, expectations feedback and almost self-fulfilling equilibria: economic theory, empirical evidence and laboratory experiments

    NARCIS (Netherlands)

    Hommes, C.


    We discuss recent work on bounded rationality and learning in relation to Soros’ principle of reflexivity and stress the empirical importance of non-rational, almost selffulfilling equilibria in positive feedback systems. As an empirical example, we discuss a behavioral asset pricing model with

  15. A Variational Principle in Reflexive Spaces with Kadec-Klee Norm

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marián; Revalski, J. P.


    Roč. 16, č. 1 (2009), s. 211-226 ISSN 0944-6532 R&D Projects: GA ČR GA201/04/0090 Institutional research plan: CEZ:AV0Z10190503 Keywords : reflexive space * Kadec-Klee norm * variational principle * perturbed function * well-posed infimum Subject RIV: BA - General Mathematics Impact factor: 0.813, year: 2009

  16. Weakly admissible $\\mathcal{H}_{\\infty}^{-}$-calculus on reflexive Banach spaces

    NARCIS (Netherlands)

    Schwenninger, F.L.; Zwart, Heiko J.


    We show that, given a reflexive Banach space and a generator of an exponentially stable $C_{0}$-semigroup, a weakly admissible operator $g(A)$ can be defined for any $g$ bounded, analytic function on the left half-plane. This yields an (unbounded) functional calculus. The construction uses a

  17. Rank-one operators in reflexive one-sided A-submodules

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    unital operator algebra A in B(H) completely. Furthermore we investigate the invariant subspace lattice Lat R and the reflexive hull Ref R, where R is the submodule generated by rank-one operators in U; in particular, if L is a subspace lattice, we obtain when the rank-one algebra R of Alg L is big enough to determined Alg L ...

  18. Blink reflexes and lateral spreading in patients with synkinesia after Bell's palsy and in hemifacial spasm

    NARCIS (Netherlands)

    Eekhof, J. L.; Aramideh, M.; Speelman, J. D.; Devriese, P. P.; Ongerboer de Visser, B. W.


    We compared various electrodiagnostical tests in patients with hemifacial spasm and in patients who developed synkinesia after Bell's palsy. We examined the evoked blink reflexes in the orbicularis oculi (o. oculi) and orbicularis oris (o. oris) muscles in 23 patients with hemifacial spasm (HFS), in

  19. Frequency response of vestibular reflexes in neck, back, and lower limb muscles

    NARCIS (Netherlands)

    Forbes, P.A.; Dakin, C.J.; Vardy, A.N.; Happee, R.; Siegmund, G.P.; Schouten, Alfred Christiaan; Blouin, J.S.


    Vestibular pathways form short-latency disynaptic connections with neck motoneurons, whereas they form longer-latency disynaptic and polysynaptic connections with lower limb motoneurons. We quantified frequency responses of vestibular reflexes in neck, back, and lower limb muscles to explain

  20. Influence of stimulus intensity on the soleus H-reflex amplitude and modulation during locomotion

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Alkjær, Tine; Raffalt, Peter C


    Diverging results have been reported regarding the modulation and amplitude of the soleus H-reflex measured during human walking and running. A possible explanation to this could be the use of too high stimulus strength in some studies while not in others. During activities like walking and runni...