WorldWideScience

Sample records for reflex control physiology

  1. [Human physiology: images and practices of the reflex].

    Science.gov (United States)

    Wübben, Yvonne

    2010-01-01

    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.

  2. Using Stimulation of the Diving Reflex in Humans to Teach Integrative Physiology

    Science.gov (United States)

    Choate, Julia K.; Denton, Kate M.; Evans, Roger G.; Hodgson, Yvonne

    2014-01-01

    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…

  3. Reflex impairment, physiological stress, and discard mortality of European plaice Pleuronectes platessa in an otter trawl fishery

    DEFF Research Database (Denmark)

    Methling, Caroline; Skov, Peter Vilhelm; Madsen, Niels

    2017-01-01

    whether reflex impairment can predict short-term mortality in commercially trawled European plaice upon landing and after air exposure of up to 90 min. Sub-lethal stress was assessed by a suite of physiological variables. Over a 10-day period, mortality was monitored for a total of 199 plaice following...... trawl and air exposure of varying duration, and for 50 control fish scored for reflex impairment on board the vessel. Mortality was only observed in fish exposed to air for >60 min, and averaged 11.1% (95% CI = 7.1–16.3%). Reflex impairment was found to be a significant (P ... of mortality in a generalized linear model, excluding other initially included variables by using a stepwise method. Plasma cortisol, haematocrit, and plasma osmolality all indicated a profound and increasing level of stress with air exposure, accompanied by a near depletion of muscle phosphocreatine...

  4. THE ANXIETY SPECTRUM AND THE REFLEX PHYSIOLOGY OF DEFENSE: FROM CIRCUMSCRIBED FEAR TO BROAD DISTRESS

    Science.gov (United States)

    McTeague, Lisa M.; Lang, Peter J.

    2013-01-01

    Guided by the diagnostic nosology, anxiety patients are expected to show defensive hyperarousal during affective challenge, irrespective of the principal phenotype. In the current study, patients representing the whole spectrum of anxiety disorders (i.e., specific phobia, social phobia, panic disorder with or without agoraphobia, obsessive-compulsive disorder, generalized anxiety disorder (GAD), posttraumatic stress disorder(PTSD)), and healthy community control participants, completed an imagery-based fear elicitation paradigm paralleling conventional intervention techniques. Participants imagined threatening and neutral narratives as physiological responses were recorded. Clear evidence emerged for exaggerated reactivity to clinically relevant imagery—most pronounced in startle reflex responding. However, defensive propensity varied across principal anxiety disorders. Disorders characterized by focal fear and impairment (e.g., specific phobia) showed robust fear potentiation. Conversely, for disorders of long-enduring, pervasive apprehension and avoidance with broad anxiety and depression comorbidity (e.g., PTSD secondary to cumulative trauma, GAD), startle responses were paradoxically diminished to all aversive contents. Patients whose expressed symptom profiles were intermediate between focal fearfulness and broad anxious-misery in both severity and chronicity exhibited a still heightened but more generalized physiological propensity to respond defensively. Importantly, this defensive physiological gradient—the inverse of self-reported distress—was evident not only between but also within disorders. These results highlight that fear circuitry could be dysregulated in chronic, pervasive anxiety, and preliminary functional neuroimaging findings suggest that deficient amygdala recruitment could underlie attenuated reflex responding. In summary, adaptive defensive engagement during imagery may be compromised by long-term dysphoria and stress—a phenomenon

  5. Reflexivity as a control factor of personal coping behavior

    OpenAIRE

    BEKHTER A.A.

    2014-01-01

    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.

  6. F response and H reflex analysis of physiological unity of gravity and antigravity muscles in man.

    Science.gov (United States)

    García, H A; Fisher, M A

    1977-01-01

    Observational differences between reflex (H reflex) and antidromic (F response) activation of segmental motoneurons by a peripheral electrical stimulus are described. In contrast to H reflexes, the percentage of F responses found after a series of stimuli is directly related to the pick-up field of the recording electrode consistent with this response being due to the variable activation of a small fraction of the available motoneuron pool. Despite the differing physiological mechanisms, both F responses and H reflexes can be used to demonstrate similar relative "central excitatory states" for antigravity muscles (i.e. extensors in the lower extremity and flexors in the upper extremity) and their antagonist gravity muscles. H reflexes were elicited not only in their usual location in certain antigravity muscles but also in unusual locations by length/tension changes in agonist and antagonist groups as well as by passive stretch. The data argue for the physiological unity of similarly acting gravity and antigravity muscles as well as supporting a meaningful role of group II afferents in normal segmental motoneuron pool excitability.

  7. Using stimulation of the diving reflex in humans to teach integrative physiology.

    Science.gov (United States)

    Choate, Julia K; Denton, Kate M; Evans, Roger G; Hodgson, Yvonne

    2014-12-01

    During underwater submersion, the body responds by conserving O2 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 stimulated in the practical laboratory setting using breath holding and facial immersion in water. Our undergraduate physiology students complete a laboratory class in which they investigate the effects of stimulating the diving reflex on cardiovascular variables, which are recorded and calculated with a Finapres finger cuff. These variables include heart rate, cardiac output, stroke volume, total peripheral resistance, and arterial pressures (mean, diastolic, and systolic). Components of the diving reflex are stimulated by 1) facial immersion in cold water (15°C), 2) breathing with a snorkel in cold water (15°C), 3) facial immersion in warm water (30°C), and 4) breath holding in air. Statistical analysis of the data generated for each of these four maneuvers allows the students to consider the factors that contribute to the diving response, such as the temperature of the water and the location of the sensory receptors that initiate the response. In addition to providing specific details about the equipment, protocols, and learning outcomes, this report describes how we assess this practical exercise and summarizes some common student misunderstandings of the essential physiological concepts underlying the diving response. Copyright © 2014 The American Physiological Society.

  8. The role of acupuncture in controlling the gagging reflex using a review of ten cases.

    Science.gov (United States)

    Fiske, J; Dickinson, C

    2001-06-09

    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.

  9. Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

    OpenAIRE

    Latash, Mark L.

    2008-01-01

    This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of m...

  10. Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis.

    Science.gov (United States)

    Latash, Mark L

    2008-01-01

    This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time.

  11. Effects of prenatal X irradiation on the appearance of reflexes and physiologic markers in the neonatal rat

    International Nuclear Information System (INIS)

    Jensh, R.P.; Brent, R.L.

    1988-01-01

    Seventy pregnant adult Wistar strain rats were randomly assigned to 1 of 12 exposure groups; 9th or 17th day irradiation at the 0-, 0.1-, 0.2-, 0.4-, 0.6-, or 0.8-Gy dosage level. On the first day of postnatal life, litters were reduced to a maximum of eight pups per litter. A total of 508 pups were observed for the age of acquisition of five reflexes (air righting, surface righting, visual placing, negative geotaxis, auditory startle) and the appearance of four physiologic markers (pinna detachment, eye opening, vaginal opening, testes descent). A dose-response relationship for alterations in reflex acquisition and physiologic marker appearance was observed due to exposure above 0.2 Gy on the 17th day of gestation. Therefore, 0.2 to 0.4-Gy exposure may represent a threshold range for exposure on the 17th day using these postnatal parameters

  12. Modeling gravity-dependent plasticity of the angular vestibuloocular reflex with a physiologically based neural network.

    Science.gov (United States)

    Xiang, Yongqing; Yakushin, Sergei B; Cohen, Bernard; Raphan, Theodore

    2006-12-01

    A neural network model was developed to explain the gravity-dependent properties of gain adaptation of the angular vestibuloocular reflex (aVOR). Gain changes are maximal at the head orientation where the gain is adapted and decrease as the head is tilted away from that position and can be described by the sum of gravity-independent and gravity-dependent components. The adaptation process was modeled by modifying the weights and bias values of a three-dimensional physiologically based neural network of canal-otolith-convergent neurons that drive the aVOR. Model parameters were trained using experimental vertical aVOR gain values. The learning rule aimed to reduce the error between eye velocities obtained from experimental gain values and model output in the position of adaptation. Although the model was trained only at specific head positions, the model predicted the experimental data at all head positions in three dimensions. Altering the relative learning rates of the weights and bias improved the model-data fits. Model predictions in three dimensions compared favorably with those of a double-sinusoid function, which is a fit that minimized the mean square error at every head position and served as the standard by which we compared the model predictions. The model supports the hypothesis that gravity-dependent adaptation of the aVOR is realized in three dimensions by a direct otolith input to canal-otolith neurons, whose canal sensitivities are adapted by the visual-vestibular mismatch. The adaptation is tuned by how the weights from otolith input to the canal-otolith-convergent neurons are adapted for a given head orientation.

  13. Physiological bases and treatment to the radiation-induced emetic reflex

    International Nuclear Information System (INIS)

    Mulen Napoles, Barbara M.; Torres Babie, Priscilla; Ropero Toirac, Ramon de J.

    2002-01-01

    In the course of the specific oncologic treatment, there are frequent complications such as nausea and vomiting. The radiation-induced emetic reflex depends on various factors: primary site of radiation, administered dose, fractioning, irradiated volume, the sensory and psychic characteristics of the patient as well as the chemotherapy association. It is known that the afferent path to the so-called center of vomiting is determined by chemical mediators, protuberance receptors of the intracranial pressure and the unleashing chemoreceptor zone. In radiation-induced emesis, the exact mechanism is yet to be determined but it is known that radiation stimulates the production of chemical mediators and serotonin released by enterochromaffin cells that act upon the center of vomiting and vagal nucleus. Most of patients who are exposed to irradiation of their upper and middle hemibody as well as all the patients exposed to whole-body irradiation present with nausea and vomiting. The therapeutical anti-emetic recommendations are based on the neurochemical control of vomiting and the emetogenic effect of radiotherapy. 5HT3 receptor-antagonists are evaluated as effective agents in the control of radiation-induced emesis

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

    Directory of Open Access Journals (Sweden)

    Serpil Akar

    2014-03-01

    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

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

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    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...... 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...... 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...

  16. Reflex control of robotic gait using human walking data.

    Directory of Open Access Journals (Sweden)

    Catherine A Macleod

    Full Text Available Control of human walking is not thoroughly understood, which has implications in developing suitable strategies for the retraining of a functional gait following neurological injuries such as spinal cord injury (SCI. Bipedal robots allow us to investigate simple elements of the complex nervous system to quantify their contribution to motor control. RunBot is a bipedal robot which operates through reflexes without using central pattern generators or trajectory planning algorithms. Ground contact information from the feet is used to activate motors in the legs, generating a gait cycle visually similar to that of humans. Rather than developing a more complicated biologically realistic neural system to control the robot's stepping, we have instead further simplified our model by measuring the correlation between heel contact and leg muscle activity (EMG in human subjects during walking and from this data created filter functions transferring the sensory data into motor actions. Adaptive filtering was used to identify the unknown transfer functions which translate the contact information into muscle activation signals. Our results show a causal relationship between ground contact information from the heel and EMG, which allows us to create a minimal, linear, analogue control system for controlling walking. The derived transfer functions were applied to RunBot II as a proof of concept. The gait cycle produced was stable and controlled, which is a positive indication that the transfer functions have potential for use in the control of assistive devices for the retraining of an efficient and effective gait with potential applications in SCI rehabilitation.

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

    Directory of Open Access Journals (Sweden)

    Schlappi Mark

    2005-08-01

    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

  18. Effects of Bed Rest on Conduction Velocity of the Triceps Surae Stretch Reflex and Postural Control

    Science.gov (United States)

    Reschke, M. F.; Wood, S. J.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.; Esteves, J. T.; Taylor, L. C.; DeDios, Y. E.; Harm, D. L.

    2011-01-01

    Despite rigorous exercise and nutritional management during space missions, astronauts returning from microgravity exhibit neuromuscular deficits and a significant loss in muscle mass in the postural muscles of the lower leg. Similar changes in the postural muscles occur in subjects participating in long-duration bed rest studies. These adaptive muscle changes manifest as a reduction in reflex conduction velocity during head-down bed rest. Because the stretch reflex encompasses both the peripheral (muscle spindle and nerve axon) and central (spinal synapse) components involved in adaptation to calf muscle unloading, it may be used to provide feedback on the general condition of neuromuscular function, and might be used to evaluate the effectiveness of countermeasures aimed at preserving muscle mass and function during periods of unloading. Stretch reflexes were measured on 18 control subjects who spent 60 to 90 days in continuous 6 deg head-down bed rest. Using a motorized system capable of rotating the foot around the ankle joint (dorsiflexion) through an angle of 10 degrees at a peak velocity of about 250 deg/sec, a stretch reflex was recorded from the subject's left triceps surae muscle group. Using surface electromyography, about 300 reflex responses were obtained and ensemble-averaged on 3 separate days before bed rest, 3 to 4 times in bed, and 3 times after bed rest. The averaged responses for each test day were examined for reflex latency and conduction velocity (CV) across gender. Computerized posturography was also conducted on these same subjects before and after bed rest as part of the standard measures. Peak-to-peak sway was measured during Sensory Organization Tests (SOTs) to evaluate changes in the ability to effectively use or suppress visual, vestibular, and proprioceptive information for postural control. Although no gender differences were found, a significant increase in reflex latency and a significant decrease in CV were observed during the bed

  19. Determination of chromosomes that control physiological traits ...

    African Journals Online (AJOL)

    Determination of chromosomes that control physiological traits associated with salt tolerance in barley at the seedling stage. ... The phenotypic traits under study included: chlorophyll contents, chlorophyll fluorescence (Fo, Fv, Fv/Fm), proline and carbohydrate rates, relative water content (RWC) and dry and wet weight of ...

  20. Oscillation and chaos in physiological control systems.

    Science.gov (United States)

    Mackey, M C; Glass, L

    1977-07-15

    First-order nonlinear differential-delay equations describing physiological control systems are studied. The equations display a broad diversity of dynamical behavior including limit cycle oscillations, with a variety of wave forms, and apparently aperiodic or "chaotic" solutions. These results are discussed in relation to dynamical respiratory and hematopoietic diseases.

  1. Muscle weakness and lack of reflex gain adaptation predominate during post-stroke posture control of the wrist

    Directory of Open Access Journals (Sweden)

    van der Helm Frans CT

    2009-07-01

    Full Text Available Abstract Background Instead of hyper-reflexia as sole paradigm, post-stroke movement disorders are currently considered the result of a complex interplay between neuronal and muscular properties, modified by level of activity. We used a closed loop system identification technique to quantify individual contributors to wrist joint stiffness during an active posture task. Methods Continuous random torque perturbations applied to the wrist joint by a haptic manipulator had to be resisted maximally. Reflex provoking conditions were applied i.e. additional viscous loads and reduced perturbation signal bandwidth. Linear system identification and neuromuscular modeling were used to separate joint stiffness into the intrinsic resistance of the muscles including co-contraction and the reflex mediated contribution. Results Compared to an age and sex matched control group, patients showed an overall 50% drop in intrinsic elasticity while their reflexive contribution did not respond to provoking conditions. Patients showed an increased mechanical stability compared to control subjects. Conclusion Post stroke, we found active posture tasking to be dominated by: 1 muscle weakness and 2 lack of reflex adaptation. This adds to existing doubts on reflex blocking therapy as the sole paradigm to improve active task performance and draws attention to muscle strength and power recovery and the role of the inability to modulate reflexes in post stroke movement disorders.

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

    NARCIS (Netherlands)

    De Bruijn, E.

    2014-01-01

    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

  3. Comparison of the physiological properties of human periodontal-masseteric reflex evoked by incisor and canine stimulation

    Directory of Open Access Journals (Sweden)

    Hiroko eOhmori

    2012-06-01

    Full Text Available Introduction: The present study was designed to clarify whether the bilateral cooperation in the human periodontal-masseteric reflex (PMR differs between central incisors and canines. Methods: Surface array electrodes were placed on the bilateral masseter muscles to simultaneously record the firing activities of single motor units from both sides in 7 healthy adults. During light clenching, mechanical stimulation was applied to the right maxillary central incisor and canine to evoke the PMR. Unitary activity was plotted with respect to the background activity and firing frequency. The slope of the regression line (sRL and the correlation coefficient (CC between the central incisor and canine and the lateral differences between these values were compared. Results: There were significant differences in the sRL and CC, as well as lateral differences, between the central incisor- and canine-driven PMR. Discussion: These results suggest that the PMR differs depending on both the tooth position and laterality.

  4. The role of sympathetic reflex control of cerebral blood flow and microcirculation during normoxia and hypoxia

    International Nuclear Information System (INIS)

    Kissen, I.

    1989-01-01

    The purpose of this study was to investigate the hypothesis that there is sympathetic reflex regulation of the cerebral blood flow (CBF) and the utilization of microvessels during normoxia and hypoxia. Regional CBF was determined in conscious Long Evans rats with 4-iodo[N-methyl- 14 C]antipyrine. The percentage of the microvessels perfused as determined by comparing perfused microvessels (FITC-dextran), with the total microvasculature (alkaline phosphatase stain). To test this hypothesis, arcs of the proposed reflex were eliminated. The first experiment examined the effect of bilateral superior cervical ganglionectomy on CBF and microcirulation during normoxia and hypoxia. CBF increased during hypoxia from 67 ± 2 to 115 ± 3 ml/min/100 g in control, and from 77 ± 2 to 155 ± 6 ml/min/100 g in ganglionectomized animals. In control, hypoxic flow to caudal areas was higher than to rostral areas and that difference was prevented by ganglionectomy. Utilization of arterioles during hypoxia increased from 51 ± 2% to 63 ± 2% in control, and from 52 ± 1% to 77 ± 2% in ganglionectomized group. The percent perfused capillaries during normoxia was 49 ± 2% in control, and 52 ± 1% in ganglionectomized group, and during hypoxia it was 73 ± 2% in both groups. In the second study, cerebral vascular responses to hypoxia were determined after administration of alpha-adrenoceptor antagonists N-methyl chlorpromazine (does not cross the blood-brain barrier), and phenoxybenzamine (crosses the blood-brain barrier). Neither phenoxybenzamine nor N-methyl chlorpromazine affected CBF and microcirculation during normoxia. During hypoxia, they similarly reversed the rostral to caudal gradient of flow, increased utilization of arterioles in rostral brain areas, and did not affect capillaries

  5. Soleus H reflex extinction in controls and spastic patients: ordered occlusion or diffuse inhibition?

    NARCIS (Netherlands)

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

    1995-01-01

    Extinction of the soleus H reflex at higher stimulus intensities is commonly attributed to retrograde conduction of action potentials in motor axons. This study was designed to gain further insight into the mechanisms underlying the extinction. The decrease of the H reflex was quantified in a group

  6. The Assessment of Postural Control, Reflex Integration, and Bilateral Motor Coordination of Young Handicapped Children. Final Report.

    Science.gov (United States)

    DeGangi, Georgia; Larsen, Lawrence A.

    A measurement device, Assessment of Sensorimotor Integration in Preschool Children, was developed to assess postural control, reflex integration and bilateral motor integration in developmentally delayed children (3 to 5 years old). The test was administered to 113 normal children and results were compared with data collected on 23 developmentally…

  7. Optical axis control system as unification of reflex and pursuit eye movements; Zentei dogan hansha, shikisei hansha, katsudosei undo wo togoshita gankyu undo seigyo model

    Energy Technology Data Exchange (ETDEWEB)

    Wakamatsu, H.; Zhang, X. [Tokyo Medical and Dental College, Tokyo (Japan)

    1997-10-20

    In order to realize basic optic axis movements, by which a moving target can be caught in a central pit of retina, an oculomotor mathematical model is developed for horizontal movements of a head and an eyeball. An image signal from retina and an acceleration signal from semicircular ducts are used as control inputs to muscles of eyeball to realize appropriate eye movements taking into account the displacement of a head rotation. Reflex eye movements and smooth pursuit as autokinesis are discussed with consideration of their control performances which lead to automatic cooperation of an appropriate control system according to the movement types of an target. The optic axis is controlled by a unified eye movement system which is synthesized on the basis of various biological facts. It has a flexible dynamics characterized by variable parameters which imply anatomical structure and physiological mechanism given by the change of synaptic conductivities in flocculus. The basic physiological facts are presented under the corresponding anatomical and physiological conditions given by appropriate changes of mathematical description of the proposed model. 14 refs., 16 figs.

  8. Cumulative vibratory indices and the H/M ratio of the soleus H-reflex: a quantitative study in control and spastic subjects

    NARCIS (Netherlands)

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

    1989-01-01

    Suppression of the soleus (Sol) H-reflex recruitment curve by Achilles tendon vibration and the ratio of maximum Sol H-reflex (Hmax) to maximum M-response (H/M ratio) have been studied by means of computer processing on the basis of peak-to-peak (P-P) and area values in 46 controls and in 16 spastic

  9. The role of GαO-mediated signaling in the rostral ventrolateral medulla oblongata in cardiovascular reflexes and control of cardiac ventricular excitability.

    Science.gov (United States)

    Ang, Richard; Abramowitz, Joel; Birnbaumer, Lutz; Gourine, Alexander V; Tinker, Andrew

    2016-08-01

    The heart is controlled by the sympathetic and parasympathetic limbs of the autonomic nervous system with inhibitory signaling mechanisms recruited in both limbs. The aim of this study was to determine the role of inhibitory heterotrimeric G proteins in the central nervous mechanisms underlying autonomic control of the heart and its potential role in arrhythmogenesis. Mice with conditional deletion of the inhibitory heterotrimeric G protein GαO in the presympathetic area of the rostral ventral lateral medulla (RVLM) were generated to determine the role of GαO-mediated signalling in autonomic control and electrophysiological properties of the heart. GαO deletion within the RVLM was not associated with changes in heart rate (HR) or the arterial blood pressure at rest (home cage, normal behavior). However, exposure to stressful conditions (novel environment, hypoxia, or hypercapnia) in these mice was associated with abnormal HR responses and an increased baroreflex gain when assessed under urethane anesthesia. This was associated with shortening of the ventricular effective refractory period. This phenotype was reversed by systemic beta-adrenoceptor blockade, suggesting that GαO depletion in the RVLM increases central sympathetic drive. The data obtained support the hypothesis that GαO-mediated signaling within the presympathetic circuits of the RVLM contributes to the autonomic control of the heart. GαO deficiency in the RVLM has a significant impact on cardiovascular responses to stress, cardiovascular reflexes and electrical properties of the heart. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  10. 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).

  11. Habituation and adaptation of the vestibuloocular reflex: a model of differential control by the vestibulocerebellum

    Science.gov (United States)

    Cohen, H.; Cohen, B.; Raphan, T.; Waespe, W.

    1992-01-01

    We habituated the dominant time constant of the horizontal vestibuloocular reflex (VOR) of rhesus and cynomolgus monkeys by repeated testing with steps of velocity about a vertical axis and adapted the gain of the VOR by altering visual input with magnifying and reducing lenses. After baseline values were established, the nodulus and ventral uvula of the vestibulocerebellum were ablated in two monkeys, and the effects of nodulouvulectomy and flocculectomy on VOR gain adaptation and habituation were compared. The VOR time constant decreased with repeated testing, rapidly at first and more slowly thereafter. The gain of the VOR was unaffected. Massed trials were more effective than distributed trials in producing habituation. Regardless of the schedule of testing, the VOR time constant never fell below the time constant of the semicircular canals (approximately 5 s). This finding indicates that only the slow component of the vestibular response, the component produced by velocity storage, was habituated. In agreement with this, the time constant of optokinetic after-nystagmus (OKAN) was habituated concurrently with the VOR. Average values for VOR habituation were obtained on a per session basis for six animals. The VOR gain was adapted by natural head movements in partially habituated monkeys while they wore x 2.2 magnifying or x 0.5 reducing lenses. Adaptation occurred rapidly and reached about +/- 30%, similar to values obtained using forced rotation. VOR gain adaptation did not cause additional habituation of the time constant. When the VOR gain was reduced in animals with a long VOR time constant, there were overshoots in eye velocity that peaked at about 6-8 s after the onset or end of constant-velocity rotation. These overshoots occurred at times when the velocity storage integrator would have been maximally activated by semicircular canal input. Since the activity generated in the canals is not altered by visual adaptation, this finding indicates that the gain

  12. Role of adenosine A2A receptor signaling in the nicotine-evoked attenuation of reflex cardiac sympathetic control

    International Nuclear Information System (INIS)

    El-Mas, Mahmoud M.; El-gowilly, Sahar M.; Fouda, Mohamed A.; Saad, Evan I.

    2011-01-01

    Baroreflex dysfunction contributes to increased cardiovascular risk in cigarette smokers. Given the importance of adenosinergic pathways in baroreflex control, the hypothesis was tested that defective central adenosinergic modulation of cardiac autonomic activity mediates the nicotine-baroreflex interaction. Baroreflex curves relating changes in heart rate (HR) to increases or decreases in blood pressure (BP) evoked by i.v. doses (1-16 μg/kg) of phenylephrine (PE) and sodium nitroprusside (SNP), respectively, were constructed in conscious rats; slopes of the curves were taken as measures of baroreflex sensitivity (BRS). Nicotine (25 and 100 μg/kg i.v.) dose-dependently reduced BRS SNP in contrast to no effect on BRS PE . BRS SNP was also attenuated after intracisternal (i.c.) administration of nicotine. Similar reductions in BRS SNP were observed in rats pretreated with atropine or propranolol. The combined treatment with nicotine and atropine produced additive inhibitory effects on BRS, an effect that was not demonstrated upon concurrent exposure to nicotine and propranolol. BRS SNP was reduced in preparations treated with i.c. 8-phenyltheophylline (8-PT, nonselective adenosine receptor antagonist), 8-(3-Chlorostyryl) caffeine (CSC, A 2A antagonist), or VUF5574 (A 3 antagonist). In contrast, BRS SNP was preserved after blockade of A 1 (DPCPX) or A 2B (alloxazine) receptors or inhibition of adenosine uptake by dipyridamole. CSC or 8-PT abrogated the BRS SNP depressant effect of nicotine whereas other adenosinergic antagonists were without effect. Together, nicotine preferentially impairs reflex tachycardia via disruption of adenosine A 2A receptor-mediated facilitation of reflex cardiac sympathoexcitation. Clinically, the attenuation by nicotine of compensatory sympathoexcitation may be detrimental in conditions such as hypothalamic defense response, posture changes, and ventricular rhythms. - Research highlights: → The role of central adenosinergic sites in

  13. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved

  14. Vestibular control of sympathetic activity. An otolith-sympathetic reflex in humans.

    Science.gov (United States)

    Kaufmann, H; Biaggioni, I; Voustianiouk, A; Diedrich, A; Costa, F; Clarke, R; Gizzi, M; Raphan, T; Cohen, B

    2002-04-01

    It has been proposed that a vestibular reflex originating in the otolith organs and other body graviceptors modulates sympathetic activity during changes in posture with regard to gravity. To test this hypothesis, we selectively stimulated otolith and body graviceptors sinusoidally along different head axes in the coronal plane with off-vertical axis rotation (OVAR) and recorded sympathetic efferent activity in the peroneal nerve (muscle sympathetic nerve activity, MSNA), blood pressure, heart rate, and respiratory rate. All parameters were entrained during OVAR at the frequency of rotation, with MSNA increasing in nose-up positions during forward linear acceleration and decreasing when nose-down. MSNA was correlated closely with blood pressure when subjects were within +/-90 degrees of nose-down positions with a delay of 1.4 s, the normal latency of baroreflex-driven changes in MSNA. Thus, in the nose-down position, MSNA was probably driven by baroreflex afferents. In contrast, when subjects were within +/-45 degrees of the nose-up position, i.e., when positive linear acceleration was maximal along the naso-ocipital axis, MSNA was closely related to gravitational acceleration at a latency of 0.4 s. This delay is too short for MSNA changes to be mediated by the baroreflex, but it is compatible with the delay of a response originating in the vestibular system. We postulate that a vestibulosympathetic reflex, probably originating mainly in the otolith organs, contributes to blood pressure maintenance during forward linear acceleration. Because of its short latency, this reflex may be one of the earliest mechanisms to sustain blood pressure upon standing.

  15. Peri- and postnatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin: effects on physiological development, reflexes, locomotor activity and learning behaviour in Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, R. (Inst. fuer Toxikologie und Embryopharmakologie, FU Berlin (Germany)); Koch, E. (Inst. fuer Toxikologie und Embryopharmakologie, FU Berlin (Germany)); Chahoud, I. (Inst. fuer Toxikologie und Embryopharmakologie, FU Berlin (Germany)); Ulbrich, B. (Bundesinstitut fuer Arzneimittel und Medizinprodukte, Berlin (Germany))

    1994-12-01

    Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development of rat offspring were studied after administration of a loading dose of 300 or 1000 ng TCDD/kg body wt on day 19 of pregnancy, followed by weekly maintenance doses of 120 or 400 ng TCDD/kg body wt. The dose regimens led to a fluctuation of average TCDD concentrations in the liver of the offspring of 4.9-14.9 ng/g (TCDD1000/400 group) or 1.4-6.3 ng/g (TCDD300/120 group) during the course of the experiment. In both TCDD-exposed groups the body weight of the offspring was significantly lower on postnatal day 7 (PND 7); in the high dose group from PND 7 to PND 31. Some landmarks of postnatal development were retarded in the exposed groups; in particular, the vaginal opening was delayed for several days in both TCDD-exposed groups. The TCDD-exposed animals revealed a reduced ability to remain on a rotating rod. During reflex testing, the rate of successfully responding animals was higher in the exposed groups. No statistically significant differences in the locomotor activity between controls and TCDD-exposed offspring were detectable under our experimental conditions. In a discrimination learning test no effects on the learning ability were found. However, TCDD-exposed offspring showed an increase in unanswered trials during critical phases of the task. They also exhibited increased locomotor activity in a novel environment; prior to an amphetamine challenge dose of 1 mg/kg body weight. Amphetamine-induced activity was decreased in a dose-dependent manner. (orig.)

  16. Variable setpoint as a relaxing component in physiological control.

    Science.gov (United States)

    Risvoll, Geir B; Thorsen, Kristian; Ruoff, Peter; Drengstig, Tormod

    2017-09-01

    Setpoints in physiology have been a puzzle for decades, and especially the notion of fixed or variable setpoints have received much attention. In this paper, we show how previously presented homeostatic controller motifs, extended with saturable signaling kinetics, can be described as variable setpoint controllers. The benefit of a variable setpoint controller is that an observed change in the concentration of the regulated biochemical species (the controlled variable) is fully characterized, and is not considered a deviation from a fixed setpoint. The variation in this biochemical species originate from variation in the disturbances (the perturbation), and thereby in the biochemical species representing the controller (the manipulated variable). Thus, we define an operational space which is spanned out by the combined high and low levels of the variations in (1) the controlled variable, (2) the manipulated variable, and (3) the perturbation. From this operational space, we investigate whether and how it imposes constraints on the different motif parameters, in order for the motif to represent a mathematical model of the regulatory system. Further analysis of the controller's ability to compensate for disturbances reveals that a variable setpoint represents a relaxing component for the controller, in that the necessary control action is reduced compared to that of a fixed setpoint controller. Such a relaxing component might serve as an important property from an evolutionary point of view. Finally, we illustrate the principles using the renal sodium and aldosterone regulatory system, where we model the variation in plasma sodium as a function of salt intake. We show that the experimentally observed variations in plasma sodium can be interpreted as a variable setpoint regulatory system. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  17. Physiology and Endocrinology Symposium. Factors controlling puberty in beef heifers

    Science.gov (United States)

    The Physiology and Endocrinology Symposium on “Factors controlling puberty in beef heifers” was held at the joint annual meeting of the American Dairy Science Association and the American Society of Animal Science in New Orleans, Louisiana, USA, July 10 to 14, 2011. The objective of the symposium w...

  18. The use of acupuncture in controlling the gag reflex in patients requiring an upper alginate impression: an audit.

    Science.gov (United States)

    Rosted, P; Bundgaard, M; Fiske, J; Pedersen, A M L

    2006-12-09

    A pronounced gag reflex (GR) can be a problem to both the acceptance and delivery of dental treatment. Despite a range of management strategies, some patients cannot accept even simple dental treatment. The aim of this study was to evaluate the use of acupuncture point CV-24 in controlling a profound gag reflex during dental treatment requiring an upper alginate impression. Members of the British Dental Acupuncture Society were invited to take part in an audit of the role of acupuncture point CV-24 in controlling the gag reflex. They were issued with patient inclusion criteria, a standardised procedure instruction sheet and a recording form. All patients fulfilling the inclusion criteria had an upper dental alginate impression taken (or an attempt made at it) before acupuncture, and a second upper alginate impression taken immediately after acupuncture of point CV-24. The GR assessment was undertaken prior to insertion of the acupuncture needle using the Gagging Severity Index (GSI); and after the acupuncture and impression taking using the Gagging Prevention Index (GPI). Both the GSI and GPI were recorded at three stages of the dental impression taking procedure, ie, when the empty impression tray was tried in the mouth, when the loaded tray was inserted into the mouth, and on completion of the impression taking. Twenty-one dentists submitted 64 case reports of which 37 fulfilled the inclusion criteria. Prior to acupuncture all 37 patients (20 females and 17 males with a mean age of 46.8 years) were unable to accept the impression taking. After acupuncture of point CV-24, an improvement of between 51-55% (mean 53%) for the three stages of impression taking was noticed. Thirty patients (81%) were able to accept the impression taking, whereas seven (19%) remained unable to tolerate the procedure. Assessed by the GSI and GPI, there was a significant decrease in GR scores at all three stages of the impression taking procedure (median 3 vs 1; 4 vs 2; 4 vs 2; p dental

  19. Digestive physiology of the pig symposium: secretion of gastrointestinal hormones and eating control.

    Science.gov (United States)

    Steinert, R E; Feinle-Bisset, C; Geary, N; Beglinger, C

    2013-05-01

    Nutrient ingestion triggers numerous changes in gastrointestinal (GI) peptide hormone secretion that affect appetite and eating. Evidence for these effects comes from research in laboratory animals, healthy humans, and, increasingly, obese patients after Roux-en-Y gastric bypass (RYGB) surgery, which has marked effects on GI hormone function and is currently the most effective therapy for morbid obesity. Increases in cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine tyrosine (PYY) and decreases in ghrelin secretion after meals are triggered by changes in the nutrient content of the intestine. One apparent physiological function of each is to initiate a reflex-like feedback control of eating. Here we briefly review this function, with an emphasis on the controls of their secretion. Each is secreted from enteroendocrine cells that are directly or indirectly affected by caloric load, macronutrient composition, and other characteristics of ingested food such as fatty acid chain length. In addition, digestive hydrolysis is a critical mechanism that controls their secretion. Although there are relatively few data in agricultural animals, the generally consistent results across widely divergent mammals suggests that most of the processes described are also likely to be relevant to GI hormone functions and eating in agricultural animals.

  20. Physiological control of behaviour in tephritid fruit flies

    International Nuclear Information System (INIS)

    Jang, Eric B.

    2000-01-01

    Studies on the behaviour of tephritid fruit flies have historically focused on the interaction of external stimuli such as temperature, semiochemicals, seasonality, etc., or the interactions of flies between and among species for a number of observed behaviours such as mating, pheromone calling and oviposition. While descriptive behaviour represent much of what we know about these pest species, less is known about the underlying physiological mechanisms which function in priming or modulation of the observed behaviour. Central to our understanding of tephritid behaviour are the multiple and often complex internal factors which are involved, and the path/mechanisms by which external stimuli result in observed behaviour. Tephritid fruit fly physiology is a vastly understudied research area which may provide important information on how peripheral receptors receive information, the transduction and coding of information centrally and how behaviour is regulated biochemically. The integration of physiology disciplines to help explain behaviour is central to the goal of developing new technology which may be useful in fruit fly control. In our laboratory, we have been studying the mechanisms of chemoreception and its link to behaviour in tephritids in such areas as olfaction, feeding, mating and oviposition. Our approach has been that tephritid behaviour can be largely influenced by their peripheral receptors which are responsible for receiving olfactory, gustatory, visual and tactile information inputs and their physiological state which controls internal modulation of behaviour. Thus, differences in behaviour between species might be explained on the basis of differences in their peripheral receptors, and the plasticity in which observed behaviour vary between the same species could very well be attributed to changes in their physiological state that are not readily apparent merely from visual observation. The importance of the physiological state in behavioural

  1. Shoulder reflexes

    DEFF Research Database (Denmark)

    Diederichsen, L.; Krogsgaard, M.; Voigt, Michael

    2002-01-01

    long latency (300 ms) excitatory reflex has been found when nerves in the capsule were stimulated electrically during shoulder surgery. In addition, when the anterior-inferior capsule was excited in conscious humans with modest amplitude electrical stimuli during muscle activity, a strong inhibition...... activity around the shoulder. This has implications for rehabilitation and shoulder surgery.......Dynamic shoulder stability is dependent on muscular coordination and sensory inputs. In the shoulder, mechanoreceptors are found in the coracoacromial ligament, the rotator cuff tendons, the musculotendinous junctions of the rotator cuff and in the capsule. The number of receptors in the capsule...

  2. Towards microprocessor-based control of droplet parameters for endoscopic laryngeal adductor reflex triggering

    Directory of Open Access Journals (Sweden)

    Fast Jacob Friedemann

    2017-09-01

    Full Text Available The so-called Laryngeal Adductor Reflex (LAR protects the respiratory tract from particle intrusion by quickly approximating the vocal folds to close the free glottal space. An impaired LAR may be associated with an increased risk of aspiration and other adverse conditions. To evaluate the integrity of the LAR, we recently developed an endoscopic prototype for LAR triggering by shooting accelerated droplets onto a predefined laryngeal target region. We now modified the existing droplet-dispensing system to adapt the fluid system pressure as well as the valve opening time to user-chosen values autonomously. This has been accomplished using a microcontroller board connected to a pressure sensor and a mechatronic syringe pump. For performance validation, we designed a measurement setup capable of tracking the droplet along a vertical trajectory. In addition to the experimental setup, the influence of parameters such as system pressure and valve opening time on the micro-droplet formation is presented. Further development will enable the physician to adjust the droplet momentum by setting a single input value on the microcontroller-based setup, thus further increasing usability of the diagnostic device.

  3. Effect of Low-level LASER Therapy on P6 Acupoint to Control Gag Reflex in Children: A Clinical Trial

    Directory of Open Access Journals (Sweden)

    Himani Goel

    2017-10-01

    Conclusion: LLLT on PC6 point was found to be effective in lowering anxiety levels as observed by faces modified anxiety rating scale. Further, it was authenticated as the pulse rates were significantly reduced and oxygen saturation levels were significantly increased. Also, gag reflex was significantly controlled when LASER stimulation was done at PC6.

  4. Acute effects of high-frequency microfocal vibratory stimulation on the H reflex of the soleus muscle. A double-blind study in healthy subjects.

    Science.gov (United States)

    Alfonsi, Enrico; Paone, Paolo; Tassorelli, Cristina; De Icco, Roberto; Moglia, Arrigo; Alvisi, Elena; Marchetta, Lucky; Fresia, Mauro; Montini, Alessandra; Calabrese, Marzia; Versiglia, Vittorio; Sandrini, Giorgio

    2015-01-01

    This study in healthy subjects examined the effects of a system delivering focal microvibrations at high frequency (Equistasi®) on tonic vibration stimulus (TVS)-induced inhibition of the soleus muscle H reflex. Highfrequency microvibrations significantly increased the inhibitory effect of TVS on the H reflex for up to three minutes. Moreover, Equistasi® also significantly reduced alpha-motoneuron excitability, as indicated by the changes in the ratio between the maximumamplitude H reflex (Hmax reflex) and the maximumamplitude muscle response (Mmax response); this effect was due to reduction of the amplitude of the H reflex because the amplitude of muscle response remained unchanged. The present findings indicate that Equistasi® has a modulatory effect on proprioceptive reflex circuits. Therefore, Equistasi® might interfere with some mechanisms involved in both physiological and pathophysiological control of movement and of posture.

  5. Plasticity of the human otolith-ocular reflex

    Science.gov (United States)

    Wall, C. 3rd; Smith, T. R.; Furman, J. M.

    1992-01-01

    The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

  6. Vegetation physiology controls continental water cycle responses to climate change

    Science.gov (United States)

    Lemordant, L. A.; Swann, A. L. S.; Cook, B.; Scheff, J.; Gentine, P.

    2017-12-01

    Abstract per se:Predicting how climate change will affect the hydrologic cycle is of utmost importance for ecological systems and for human life and activities. A typical perspective is that global warming will cause an intensification of the mean state, the so-called "dry gets drier, wet gets wetter" paradigm. While this result is robust over the oceans, recent works suggest it may be less appropriate for terrestrial regions. Using Earth System Models (ESMs) with decoupled surface (vegetation physiology, PHYS) and atmospheric (radiative, ATMO) CO2 responses, we show that the CO2 physiological response dominates the change in the continental hydrologic cycle compared to radiative and precipitation changes due to increased atmospheric CO2, counter to previous assumptions. Using multiple linear regression analysis, we estimate the individual contribution of each of the three main drivers, precipitation, radiation and physiological CO2 forcing (see attached figure). Our analysis reveals that physiological effects dominate changes for 3 key indicators of dryness and/or vegetation stress (namely LAI, P-ET and EF) over the largest fraction of the globe, except for soil moisture which exhibits a more complex response. This highlights the key role of vegetation in controlling future terrestrial hydrologic response.Legend of the Figure attached:Decomposition along the three main drivers of LAI (a), P-ET (b), EF (c) in the control run. Green quantifies the effect of the vegetation physiology based on the run PHYS; red and blue quantify the contribution of, respectively, net radiation and precipitation, based on multiple linear regression in ATMO. Pie charts show for each variable the fraction (labelled in %) of land under the main influence (more than 50% of the changes is attributed to this driver) of one the three main drivers (green for grid points dominated by vegetation physiology, red for grid points dominated by net radiation, and blue for grid points dominated by the

  7. Presbypropria: the effects of physiological ageing on proprioceptive control.

    Science.gov (United States)

    Boisgontier, Matthieu P; Olivier, Isabelle; Chenu, Olivier; Nougier, Vincent

    2012-10-01

    Several changes in the human sensory systems, like presbycusis or presbyopia, are well-known to occur with physiological ageing. A similar change is likely to occur in proprioception, too, but there are strong and unexplained discrepancies in the literature. It was proposed that assessment of the attentional cost of proprioceptive control could provide information able to unify these previous studies. To this aim, 15 young adults and 15 older adults performed a position matching task in single and dual-task paradigms with different difficulty levels of the secondary task (congruent and incongruent Stroop-type tasks) to assess presumed age-related deficits in proprioceptive control. Results showed that proprioceptive control was as accurate and as consistent in older as in young adults for a single proprioceptive task. However, performing a secondary cognitive task and increasing the difficulty of this secondary task evidenced both a decreased matching performance and/or an increased attentional cost of proprioceptive control in older adults as compared to young ones. These results advocated for an impaired proprioception in physiological ageing.

  8. Dorsal light reflex is absent in the postural control system of the upside-down swimming catfish, Synodontis nigriventris

    Science.gov (United States)

    Ohnishi, T.; Ohnishi, K.; Okamoto, N.; Yamamoto, T.; Hosoi, H.; Takahashi, A.; Kawai, H.

    A kind of catfish, Synodontis nigriventris, has a unique habit of maintaining an upside-down posture under normal gravity conditions (1 G). We exposed S. nigriventris to a microgravity environment provided by the parabolic flights of an aircraft and observed the dorsal light reflex (DLR), which is well known to be an important visually guided postural reaction in fish. In general, fish directs its back to an illuminated direction, depending on DLR: DLR is observed more clearly under microgravity as compared with 1 G. Interestingly, S. nigriventris exhibited no DLR response even under microgravity. In contrast, clear DLR was observed under microgravity in two other species, which have an upside-up swimming habit, Synodontis multipunctatus, belonging to the same Synodontis family, and Corydoras paleatus, belonging to a different catfish family. Our parabolic flight experiments have confirmed for the first time that S. nigriventris has a novel balance sensation which does not induce DLR. This allows us to address a new and attractive strategy for the analysis of the postural control mechanism of vertebrate.

  9. Correlation analysis of the physiological factors controlling fundamental voice frequency.

    Science.gov (United States)

    Atkinson, J E

    1978-01-01

    A technique has been developed to obtain a quantitative measure of correlation between electromyographic (EMG) activity of various laryngeal muscles, subglottal air pressure, and the fundamental frequency of vibration of the vocal folds (Fo). Data were collected and analyzed on one subject, a native speaker of American English. The results show that an analysis of this type can provide a useful measure of correlation between the physiological and acoustical events in speech and, furthermore, can yield detailed insights into the organization and nature of the speech production process. In particular, based on these results, a model is suggested of Fo control involving laryngeal state functions that seems to agree with present knowledge of laryngeal control and experimental evidence.

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

    Directory of Open Access Journals (Sweden)

    Kalyan B Bhattacharyya

    2017-01-01

    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.

  11. Sympathetic reflex control of skeletal muscle blood flow in patients with congestive heart failure: evidence for beta-adrenergic circulatory control

    International Nuclear Information System (INIS)

    Kassis, E.; Jacobsen, T.N.; Mogensen, F.; Amtorp, O.

    1986-01-01

    Mechanisms controlling forearm muscle vascular resistance (FMVR) during postural changes were investigated in seven patients with severe congestive heart failure (CHF) and in seven control subjects with unimpaired left ventricular function. Relative brachioradial muscle blood flow was determined by the local 133 Xe-washout technique. Unloading of baroreceptors with use of 45 degree upright tilt was comparably obtained in the patients with CHF and control subjects. Control subjects had substantially increased FMVR and heart rate to maintain arterial pressure whereas patients with CHF had decreased FMVR by 51 +/- 11% and had no increase in heart rate despite a fall in arterial pressure during upright tilt. The autoregulatory and local vasoconstrictor reflex responsiveness during postural changes in forearm vascular pressures were intact in both groups. In the patients with CHF, the left axillary nerve plexus was blocked by local anesthesia. No alterations in forearm vascular pressures were observed. This blockade preserved the local regulation of FMVR but reversed the vasodilator response to upright tilt as FMVR increased by 30 +/- 7% (p less than .02). Blockade of central neural impulses to this limb combined with brachial arterial infusions of phentolamine completely abolished the humoral vasoconstriction in the tilted position. Infusions of propranolol to the contralateral brachial artery that did not affect baseline values of heart rate, arterial pressure, or the local reflex regulation of FMVR reversed the abnormal vasodilator response to upright tilt as FMVR increased by 42 +/- 12% (p less than .02). Despite augmented baseline values, forearm venous but not arterial plasma levels of epinephrine increased in the tilted position, as did arteri rather than venous plasma concentrations of norepinephrine in these patients

  12. Role of ionotropic GABA, glutamate and glycine receptors in the tonic and reflex control of cardiac vagal outflow in the rat

    Directory of Open Access Journals (Sweden)

    Goodchild Ann K

    2010-10-01

    Full Text Available Abstract Background Cardiac vagal preganglionic neurons (CVPN are responsible for the tonic, reflex and respiratory modulation of heart rate (HR. Although CVPN receive GABAergic and glutamatergic inputs, likely involved in respiratory and reflex modulation of HR respectively, little else is known regarding the functions controlled by ionotropic inputs. Activation of g-protein coupled receptors (GPCR alters these inputs, but the functional consequence is largely unknown. The present study aimed to delineate how ionotropic GABAergic, glycinergic and glutamatergic inputs contribute to the tonic and reflex control of HR and in particular determine which receptor subtypes were involved. Furthermore, we wished to establish how activation of the 5-HT1A GPCR affects tonic and reflex control of HR and what ionotropic interactions this might involve. Results Microinjection of the GABAA antagonist picrotoxin into CVPN decreased HR but did not affect baroreflex bradycardia. The glycine antagonist strychnine did not alter HR or baroreflex bradycardia. Combined microinjection of the NMDA antagonist, MK801, and AMPA antagonist, CNQX, into CVPN evoked a small bradycardia and abolished baroreflex bradycardia. MK801 attenuated whereas CNQX abolished baroreceptor bradycardia. Control intravenous injections of the 5-HT1A agonist 8-OH-DPAT evoked a small bradycardia and potentiated baroreflex bradycardia. These effects were still observed following microinjection of picrotoxin but not strychnine into CVPN. Conclusions We conclude that activation of GABAA receptors set the level of HR whereas AMPA to a greater extent than NMDA receptors elicit baroreflex changes in HR. Furthermore, activation of 5-HT1A receptors evokes bradycardia and enhances baroreflex changes in HR due to interactions with glycinergic neurons involving strychnine receptors. This study provides reference for future studies investigating how diseases alter neurochemical inputs to CVPN.

  13. Reflex syncope, anxiety level, and family history of cardiovascular disease in young women: case-control study.

    Science.gov (United States)

    Zyśko, D; Szewczuk-Bogusławska, M; Kaczmarek, M; Agrawal, A K; Rudnicki, J; Gajek, J; Melander, O; Sutton, R; Fedorowski, A

    2015-02-01

    Anxiety is an emotion, which stimulates sympathetic nervous outflow potentially facilitating vasovagal reflex syncope (VVS) but reports on anxiety levels in patients with VVS are sparse. We studied anxiety levels in young women (21-40 years) referred for unexplained transient loss of consciousness (TLOC), and age-matched female controls with or without past history of TLOC (≈probable VVS). Referred patients underwent head-up tilt (HUT) according to current ESC Guidelines. State and Trait Anxiety Inventory questionnaire evaluated anxiety levels plus a questionnaire explored risk factors for cardiovascular disease (CVD). Sixty-five of 91 women were diagnosed with VVS on HUT. Among 549 controls, 223 (40.6%) reported at least one episode of TLOC. State-anxiety level in patients with VVS undergoing HUT (42.4 ± 9.3) was higher compared with both controls with (38.3 ± 10.2; P < 0.01) and without past TLOC history (35.9 ± 9.8; P < 0.001). Trait anxiety in patients with VVS (42.7 ± 8.4), and controls with TLOC history (42.4 ± 8.4) was higher compared with controls without TLOC history (39.7 ± 8.5; P < 0.01). In the logistic regression using controls without TLOC as reference, both VVS diagnosis and past history of TLOC were associated with family history of CVD [odds ratio (OR) 2.4, 95% confidence interval (CI), 1.3-4.4; P = 0.007, and 2.3, 1.4-3.6; P = 0.001, respectively], and this association was independent of anxiety level. Trait anxiety and family history of CVD are increased in both young women with VVS and controls with history of TLOC. However, the height of anxiety level does not explain CVD heredity and other mechanisms may link syncope with CVD. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  14. Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

    Science.gov (United States)

    Castro-Sánchez, Adelaida María; Moreno-Lorenzo, Carmen; Matarán-Peñarrocha, Guillermo A.; Feriche-Fernández-Castanys, Belen; Granados-Gámez, Genoveva; Quesada-Rubio, José Manuel

    2011-01-01

    The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD) (Leriche-Fontaine classification) were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30 min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P < .05) in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg) and left lower limb (lower one-third of thigh and upper and lower one-third of leg). A significant difference (P < .05) was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P < .05) for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD. PMID:19933770

  15. Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Adelaida María Castro-Sánchez

    2011-01-01

    Full Text Available The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD (Leriche-Fontaine classification were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30 min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P<.05 in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg and left lower limb (lower one-third of thigh and upper and lower one-third of leg. A significant difference (P<.05 was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P<.05 for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD.

  16. ZAG-Otolith: Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control during Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, S. J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved with vibrotactile feedback of orientation.

  17. Fundamental Principles underlying Motor Reflexes

    NARCIS (Netherlands)

    K. Zhou (Kuikui)

    2017-01-01

    markdownabstractThe cerebellum has been suggested to be involved in motor control ever since the early 19th century. The motor control ranges from timing and strength of simple reflexes to multiple joint/limb coordination and complex motor sequence acquisition. The current thesis discusses the

  18. A High-Gain Reflex-Based Bidirectional DC Charger with Efficient Energy Recycling for Low-Voltage Battery Charging-Discharging Power Control

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2018-03-01

    Full Text Available This study proposes a high-gain reflex-charging-based bidirectional DC charger (RC-BDC to enhance the battery charging efficiency of light electric vehicles (LEV in a DC-microgrid. The proposed charger topology consists of an unregulated level converter (ULC and a two-phase interleaved buck-boost charge-pump converter (IBCPC, which together provide low ripple and high voltage conversion ratio. As the high-gain RC-BDC charges, the LEV’s battery with reflex charging currents, high battery charging efficiency, and prolonged battery life cycles are achieved. This is possible due to the recovering of negative pulse energy of reflex charging currents to reduce charge dissipations within LEV’s batteries. Derivations of the operating principles of the high-gain RC-BDC, analyses of its topology, and the closed-loop control designs were presented. Simulations and experiments were implemented with battery voltage of 48 V and DC-bus voltage of 400 V for a 500 W prototype. The results verify the feasibility of the proposed concept and were compared with the typical constant-current/constant-voltage (CC/CV charger. The comparison shows that the proposed high gain RC-BDC improves battery charging speed and reduces the battery thermal deterioration effect by about 12.7% and 25%, respectively.

  19. A condição obscura: Reflexões sobre as políticas de imigração e controle de estrangeiros em Portugal

    Directory of Open Access Journals (Sweden)

    Igor José de Renó Machado

    2012-11-01

    Full Text Available O artigo propõe uma reflexão antropológica sobre as leis portuguesas de controle da imigração e concessão de nacionalidade. Ao mesmo tempo que procuram estabilizar um contingente de imigrantes numa condição vulnerável, as leis, como um todo, compartilham uma noção de aversão à diferença radical, procurando sempre aportuguesar os estrangeiros. Os diferentes mecanismos construídos para atingir esse objetivo são analisados em detalhe.

  20. Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex

    Directory of Open Access Journals (Sweden)

    Asger Emil Munch Schrøder

    2017-04-01

    Full Text Available Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs. We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.

  1. Attentional modulation of reflex cough.

    Science.gov (United States)

    Janssens, Thomas; Silva, Mitchell; Davenport, Paul W; Van Diest, Ilse; Dupont, Lieven J; Van den Bergh, Omer

    2014-07-01

    Reflex cough is a defensive response generated in the brainstem in response to chemical and mechanical stimulation of the airways. However, converging evidence shows that reflex cough is also influenced by central neural control processes. In this study, we investigate whether reflex cough can be modulated by attentional focus on either external stimuli or internal cough-related stimuli. Healthy volunteers (N = 24; seven men; age range, 18-25 years) completed four blocks of citric acid-induced cough challenges while, simultaneously, auditory stimuli were presented. Within each block, four concentrations were administered (30, 100, 300 and 1,000 mM, randomized). During two subsequent blocks, participants focused their attention externally (counting tones). During the other two blocks, participants focused their attention internally (counting coughs). The order of attentional focus was counterbalanced across participants. Ratings of the urge to cough were collected after each challenge. Cough frequency was determined by audio recording. Cough frequency was higher when participants focused their attention internally vs externally (P Reflex cough can be modulated by attentional focus. Internally focused attention may be a mechanism involved in excessive (idiopathic) cough, while an external focus may be introduced as part of treatments targeting excessive cough.

  2. Reflexivity in qualitative research

    DEFF Research Database (Denmark)

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

    2018-01-01

    There has been something of a “reflexive shift” in sociological research. Sociological researchers are increasingly encouraged to be “present” within their work, and to recognize their own role in structuring the entire research process. One way to achieve this is through engagement in reflexive...... 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...... Kingdom. Reflexive practice in both studies was affected by researcher biographies and by study design. In Study 1, both researchers were reasonably detached from the study context, the theoretical framework was in place from the very beginning, and reflexive practice was embedded in the study design...

  3. Sex differences in cough reflex.

    Science.gov (United States)

    Plevkova, J; Buday, T; Kavalcikova-Bogdanova, N; Ioan, I; Demoulin-Alexikova, S

    2017-11-01

    Majority of patients visiting cough clinics are postmenopausal women, who are affected by intractable cough for years. Why the cough reflex becomes exaggerated in women is not known. Basic research excludes females from the studies contributing to the sex bias which may be responsible for lack of understanding of "hypersensitive" cough in women. Biological and behavioural differences between women and men are the factors affecting cough physiology. Gender also shapes the patterns of behaviour and determines the character of environmental exposures which differs between sexes. The article offers an insight into the physiology of the cough, differences in the maturation of it and biological, social and behavioural factors contributing to the sex differences in cough. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Nuclear techniques in plant pathology 1. Plant disease control and physiology of parasitism

    International Nuclear Information System (INIS)

    Menten, J.O.M.; Ando, A.; Tulmann Neto, A.

    1986-01-01

    Nuclear techniques are advantageously used in several areas of plant pathology. Among them are: induction of mutation for disease resistance, studies with pesticides, disease control through pathogen inactivation, induction of variability and stimulation in pathogens and natural enemies, studies of microorganism physiology and diseased plant physiology, effect of gamma radiation on pesticides, technology of pesticides application, etc. (Author) [pt

  5. Etnography and Reflexivity

    Directory of Open Access Journals (Sweden)

    Mario Cardano

    2014-01-01

    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.

  6. On Reflexive Data Models

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, S.

    2000-08-20

    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.

  7. The mechano-gated channel inhibitor GsMTx4 reduces the exercise pressor reflex in decerebrate rats.

    Science.gov (United States)

    Copp, Steven W; Kim, Joyce S; Ruiz-Velasco, Victor; Kaufman, Marc P

    2016-02-01

    Mechanical and metabolic stimuli from contracting muscles evoke reflex increases in blood pressure, heart rate and sympathetic nerve activity. Little is known, however, about the nature of the mechano-gated channels on the thin fibre muscle afferents that contribute to evoke this reflex, termed the exercise pressor reflex. We determined the effect of GsMTx4, an inhibitor of mechano-gated Piezo channels, on the exercise pressor reflex evoked by intermittent contraction of the triceps surae muscles in decerebrated, unanaesthetized rats. GsMTx4 reduced the pressor, cardioaccelerator and renal sympathetic nerve responses to intermittent contraction but did not reduce the pressor responses to femoral arterial injection of compounds that stimulate the metabolically-sensitive thin fibre muscle afferents. Expression levels of Piezo2 channels were greater than Piezo1 channels in rat dorsal root ganglia. Our findings suggest that mechanically-sensitive Piezo proteins contribute to the generation of the mechanical component of the exercise pressor reflex in rats. Mechanical and metabolic stimuli within contracting skeletal muscles evoke reflex autonomic and cardiovascular adjustments. In cats and rats, gadolinium has been used to investigate the role played by the mechanical component of this reflex, termed the exercise pressor reflex. Gadolinium, however, has poor selectivity for mechano-gated channels and exerts multiple off-target effects. We tested the hypothesis that GsMTX4, a more selective mechano-gated channel inhibitor than gadolinium and a particularly potent inhibitor of mechano-gated Piezo channels, reduced the exercise pressor reflex in decerebrate rats. Injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the peak pressor (control: 24 ± 5, GsMTx4: 12 ± 5 mmHg, P acid. Moreover, injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the peak pressor (control: 24 ± 2, GsMTx4: 14 ± 3 mmHg, P reflex in

  8. Physiological Feedback Control 2011-2012 Annual Report

    Science.gov (United States)

    2013-01-07

    Desai, James R. Baker Jr., Bradford G. Orr, Mark M. Banaszak Holl. The effect of mass transport in the synthesis of partially acetylated dendrimer ...Invention Title: UM 3709 – Dendrimeric Prodrug as a Controlled Release Formulation in Pain Management – Patent Title: Dendrimer Conjugates Patent... Dendrimeric Prodrug as a Controlled Release Formulation in Pain Management – Patent Title: Dendrimer Conjugates Patent/Application Numbers: 61/101,461; 12

  9. Insect vectors of Leishmania: distribution, physiology and their control.

    Science.gov (United States)

    Sharma, Umakant; Singh, Sarman

    2008-12-01

    Leishmaniasis is a deadly vector-borne disease that causes significant morbidity and mortality in Africa, Asia, Latin America and Mediterranean regions. The causative agent of leishmaniasis is transmitted from man to man by a tiny insect called sandfly. Approximately, 600 species of sandflies are known but only 10% of these act as disease vectors. Further, only 30 species of these are important from public health point. Fauna of Indian sub-zone is represented by 46 species, of these, 11 belong to Phlebotomine species and 35 to Sergentomyia species. Phlebotomus argentipes is the proven vector of kala-azar or visceral leishmaniasis in India. This review gives an insight into the insect vectors of human leishmaniasis, their geographical distribution, recent taxonomic classification, habitat, and different control measures including indoor residual spraying (IRS), insecticide-treated bednets (ITNs), environmental management, biological control, and emerging resistance to DDT. Role of satellite remote sensing for early prediction of the disease by identifying the sandflygenic conditions cannot be undermined. The article also underlines the importance of synthetic pheromones which can be used in near future for the control of these vectors.

  10. Too Busy for Reflexivity?

    DEFF Research Database (Denmark)

    Ratner, Helene

    What Danish school managers can teach STS researchers about epistemological ideals and pragmatic morals. Reflexivity has an ambivalent status in both anthropology and Science and Technology Studies. On the one hand, the critique of representation at the heart of the reflexivity debates of the 1980s...... highlighted non-symmetric relationships between observer and observed and accused the academic text of enacting a realist genre, concealing the relativism entailed in textual production (Clifford and Marcus 1986, Woolgar 1988, Ashmore 1989). On the other hand, the reflexivity program produced fears...... 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...

  11. Ecosystem and physiological controls over methane production in northern wetlands

    Science.gov (United States)

    Valentine, David W.; Holland, Elisabeth A.; Schimel, David S.

    1994-01-01

    Peat chemistry appears to exert primary control over methane production rates in the Canadian Northern Wetlands Study (NOWES) area. We determined laboratory methane production rate potentials in anaerobic slurries of samples collected from a transect of sites through the NOWES study area. We related methane production rates to indicators of resistance to microbial decay (peat C: N and lignin: N ratios) and experimentally manipulated substrate availability for methanogenesis using ethanol (EtOH) and plant litter. We also determined responses of methane production to pH and temperature. Methane production potentials declined along the gradient of sites from high rates in the coastal fens to low rates in the interior bogs and were generally highest in surface layers. Strong relationships between CH4 production potentials and peat chemistry suggested that methanogenesis was limited by fermentation rates. Methane production at ambient pH responded strongly to substrate additions in the circumneutral fens with narrow lignin: N and C: N ratios (delta CH4/delta EtOH = 0.9-2.3 mg/g) and weakly in the acidic bogs with wide C: N and lignin: N ratios (delta CH4/delta EtOH = -0.04-0.02 mg/g). Observed Q(sub 10) values ranged from 1.7 to 4.7 and generally increased with increasing substrate availability, suggesting that fermentation rates were limiting. Titration experiments generally demonstrated inhibition of methanogenesis by low pH. Our results suggest that the low rates of methane emission observed in interior bogs during NOWES likely resulted from pH and substrate quality limitation of the fermentation step in methane production and thus reflect intrinsically low methane production potentials. Low methane emission rates observed during NOWES will likely be observed in other northern wetland regions with similar vegetation chemistry.

  12. A novel reflex cough testing device.

    Science.gov (United States)

    Fujiwara, Kazunori; Kawamoto, Katsuyuki; Shimizu, Yoko; Fukuhara, Takahiro; Koyama, Satoshi; Kataoka, Hideyuki; Kitano, Hiroya; Takeuchi, Hiromi

    2017-01-18

    The reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia. This device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer. The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group). With the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.

  13. Reflexivity and social justice

    DEFF Research Database (Denmark)

    Maksimovic, Tijana; Jakobsen, Helle Nordentoft

    2017-01-01

    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...

  14. Development of a cerebral circulation model for the automatic control of brain physiology.

    Science.gov (United States)

    Utsuki, T

    2015-01-01

    In various clinical guidelines of brain injury, intracranial pressure (ICP), cerebral blood flow (CBF) and brain temperature (BT) are essential targets for precise management for brain resuscitation. In addition, the integrated automatic control of BT, ICP, and CBF is required for improving therapeutic effects and reducing medical costs and staff burden. Thus, a new model of cerebral circulation was developed in this study for integrative automatic control. With this model, the CBF and cerebral perfusion pressure of a normal adult male were regionally calculated according to cerebrovascular structure, blood viscosity, blood distribution, CBF autoregulation, and ICP. The analysis results were consistent with physiological knowledge already obtained with conventional studies. Therefore, the developed model is potentially available for the integrative control of the physiological state of the brain as a reference model of an automatic control system, or as a controlled object in various control simulations.

  15. [Laryngeal adduction reflex].

    Science.gov (United States)

    Ptok, M; Bonenberger, S; Miller, S; Kühn, D; Jungheim, M

    2014-07-01

    Laryngeal Adductor Reflex Background: A rapid closure of the vocal folds is necessary, whenever foreign materials or food particles penetrate into the larynx. Otherwise a passage of these particles into the trachea or the lower respiratory tract would be imminent. An aspiration could mechanically block the respiratory tract and cause severe dyspnoea or cause aspiration pneumonia. For this systematic review a selective literature research in PubMed and Scopus using the keywords "laryngeal adductor reflex" and "vocal fold closure" has been carried out. Apart from the oesophago-glottal and pharyngo-glottal closure reflexes, the laryngeal adductor reflex (LAR) has been investigated in particular. The LAR qualifies as a reflectory laryngeal adductor mechanism and involves early, presumably di- or oligosynaptic ipsilateral LAR1 as well as late polysynaptic ipsi- and contralateral LAR2 components. In clinical routine diagnostic settings of dysphagia, LAR is only assessed qualitatively and usually triggered by air pulses or tactile stimulation. Dysphagiologists often find that not only the laryngeal sensibility in general is impaired, but especially the protective laryngeal adduction mechanism, which results in a higher risk of aspiration. Thus, it appears mandatory to test the LAR not only qualitatively but also quantitatively. Unfortunately a valid and reliable method that can be employed in clinical practice has not yet been put forward. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Physiological coherence in healthy volunteers during laboratory-induced stress and controlled breathing.

    Science.gov (United States)

    Mejía-Mejía, Elisa; Torres, Robinson; Restrepo, Diana

    2018-06-01

    Physiological coherence has been related with a general sense of well-being and improvements in health and physical, social, and cognitive performance. The aim of this study was to evaluate the relationship between acute stress, controlled breathing, and physiological coherence, and the degree of body systems synchronization during a coherence-generation exercise. Thirty-four university employees were evaluated during a 20-min test consisting of four stages of 5-min duration each, during which basal measurements were obtained (Stage 1), acute stress was induced using validated mental stressors (Stroop test and mental arithmetic task, during Stage 2 and 3, respectively), and coherence states were generated using a controlled breathing technique (Stage 4). Physiological coherence and cardiorespiratory synchronization were assessed during each stage from heart rate variability, pulse transit time, and respiration. Coherence measurements derived from the three analyzed variables increased during controlled respiration. Moreover, signals synchronized during the controlled breathing stage, implying a cardiorespiratory synchronization was achieved by most participants. Hence, physiological coherence and cardiopulmonary synchronization, which could lead to improvements in health and better life quality, can be achieved using slow, controlled breathing exercises. Meanwhile, coherence measured during basal state and stressful situations did not show relevant differences using heart rate variability and pulse transit time. More studies are needed to evaluate the ability of coherence ratio to reflect acute stress. © 2017 Society for Psychophysiological Research.

  17. The mechano-gated channel inhibitor GsMTx4 reduces the exercise pressor reflex in rats with ligated femoral arteries.

    Science.gov (United States)

    Copp, Steven W; Kim, Joyce S; Ruiz-Velasco, Victor; Kaufman, Marc P

    2016-05-01

    Mechanical and metabolic stimuli arising from contracting muscles evoke the exercise pressor reflex. This reflex is greater in a rat model of simulated peripheral arterial disease in which a femoral artery is chronically ligated than it is in rats with freely perfused femoral arteries. The role played by the mechanically sensitive component of the exaggerated exercise pressor reflex in ligated rats is unknown. We tested the hypothesis that the mechano-gated channel inhibitor GsMTx4, a relatively selective inhibitor of mechano-gated Piezo channels, reduces the exercise pressor reflex in decerebrate rats with ligated femoral arteries. Injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the pressor response to Achilles tendon stretch (a purely mechanical stimulus) but had no effect on the pressor responses to intra-arterial injection of α,β-methylene ATP or lactic acid (purely metabolic stimuli). Moreover, injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced both the integrated pressor area (control 535 ± 21, GsMTx4 218 ± 24 mmHg·s; P reflex contributes to the exaggerated exercise pressor reflex during intermittent hindlimb muscle contractions in rats with ligated femoral arteries. Copyright © 2016 the American Physiological Society.

  18. Shared control of gene expression in bacteria by transcription factors and global physiology of the cell.

    NARCIS (Netherlands)

    Berthoumieux, S.; Jong, H. de; Baptist, G.; Pinel, C.; Ranquet, C.; Ropers, D.; Geiselmann, J.

    2013-01-01

    Gene expression is controlled by the joint effect of (i) the global physiological state of the cell, in particular the activity of the gene expression machinery, and (ii) DNA-binding transcription factors and other specific regulators. We present a model-based approach to distinguish between these

  19. Control analysis of the dependence of Escherichia coli physiology on the H+ -ATPase

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Michelsen, Ole; Westerhoff, Hans V.

    1993-01-01

    The H+-ATPase plays a central role in Escherichia coli free-energy transduction and hence in E. coli physiology. We here investigate the extent to which this enzyme also controls the growth rate, growth yield, and respiratory rate of E. coli. We modulate the expression of the atp operon and deter...

  20. Operators work reliability current control based on the psychological and physiological criteria

    International Nuclear Information System (INIS)

    Karpenko, A.V.; Burov, A.Yu.; Grigorus', A.G.; Kal'nish, V.V.; Kapshuk, A.P.; Grigor'yants, T.N.; Bobko, N.A.

    1984-01-01

    A possibility of developing highly sensitive criteria for assessment of mental working ability at the expense of profound automated analysis of available psychological and physiological criteria is disclosed; it is a precondition for developing operator is woAking ability control system not requiring additional personnel for its operation

  1. Excess control rights: a study about its reflex on the cost of debt of publicly traded Brazilian companies

    Directory of Open Access Journals (Sweden)

    Jonatan Marlon Konraht

    2016-08-01

    Full Text Available This study analyzes the effect of excess control on the cost of debt in publicly traded Brazilian companies. Its objective is to determine whether a higher misalignment between voting rights and cash flow rights held by controlling shareholder causes an increase in agency cost of debt. For the analysis of the research problem, it was used panel data regression with random effects, in which was compared the level of excess control and the firms cost of debt. The results indicate that there is a positive and statistically significant association between excess control and the cost of debt. This suggests that creditors interpret this misalignment as a control entrenchment, which increases the credit risk, and thereby, increases the cost of debt. From the scientific point of view, the contribution to the literature provided by this study is the finding that ownership structure bears an impact in the creditor perceptions of risk, and thus, the cost of debt. These results can assist in developing actions to reduce the cost of debt, which implies the maximization of the economic performance of firms that have third-party capital in its capital structure. Its social contribution is the distinction of the firms exposed to a higher level of cost of debt, identifying ways to maximize resources, that is a relevant aspect especially in times of crisis whose effects can be very varied, such as bankruptcies, massive layoffs and default.

  2. Reflex control of heart rate in normal subjects in relation to age: a data base for cardiac vagal neuropathy

    NARCIS (Netherlands)

    Wieling, W.; van Brederode, J. F.; de Rijk, L. G.; Borst, C.; Dunning, A. J.

    1982-01-01

    We examined the heart rate changes induced by forced breathing and by standing up in 133 healthy subjects in the age range 10-65 years in order to establish a data base for studies on parasympathetic heart rate control in autonomic neuropathy. Test results declined with age. Log-transformation was

  3. Moving beyond command-and-control: reflexivity in the regulation of occupational safety and health and the environment.

    NARCIS (Netherlands)

    Aalders, M.V.C.; Wilthagen, T.

    1997-01-01

    Direct or "command-and-control" regulation has had limited success in dealing with occupational health and safety and with environmental regulation. This lack of success has led policymakers to experiment with self-regulation as an alternative means of achieving the goals of social regulation. The

  4. Reflex epilepsy: a review

    Directory of Open Access Journals (Sweden)

    Karim Nikkhah

    2017-01-01

    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.

  5. Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder

    Science.gov (United States)

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

    2010-01-01

    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…

  6. Advantages and Disadvantages of Physiological Assessment For Next Generation Control Room Design

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Q. Tran; Ronald L. Boring; Donald D. Dudenhoeffer; Bruce P Hallbert; M. David Keller; Tessa M. Anderson

    2007-08-01

    Abstract - We propose using non-obtrusive physiological assessment (e.g., eye tracking,) to assess human information processing errors (e.g., loss of vigilance) and limitations (e.g., workload) for advanced energy systems early in the design process. This physiological approach for assessing risk will circumvent many limitations of current risk methodologies such as subjective rating (e.g., rater’s biases) and performance modeling (e.g., risk assessment is scripted and is based upon the individual modeler’s judgment). Key uses will be to evaluate (early in the design process) novel control room equipment and configurations as well as newly developed automated systems that will inevitably place a high information load on operators. The physiological risk assessment tool will allow better precision in pinpointing problematic design issues and will provide a “real-time” assessment of risk. Furthermore, this physiological approach would extend the state-of-the-art of human reliability methods from a “static” measure to more “dynamic.” This paper will discuss a broad range of the current popular online performance gauges as well as its advantages and disadvantages for use in next generation control room.

  7. Network interactions within the canine intrinsic cardiac nervous system: implications for reflex control of regional cardiac function

    Science.gov (United States)

    Beaumont, Eric; Salavatian, Siamak; Southerland, E Marie; Vinet, Alain; Jacquemet, Vincent; Armour, J Andrew; Ardell, Jeffrey L

    2013-01-01

    The aims of the study were to determine how aggregates of intrinsic cardiac (IC) neurons transduce the cardiovascular milieu versus responding to changes in central neuronal drive and to determine IC network interactions subsequent to induced neural imbalances in the genesis of atrial fibrillation (AF). Activity from multiple IC neurons in the right atrial ganglionated plexus was recorded in eight anaesthetized canines using a 16-channel linear microelectrode array. Induced changes in IC neuronal activity were evaluated in response to: (1) focal cardiac mechanical distortion; (2) electrical activation of cervical vagi or stellate ganglia; (3) occlusion of the inferior vena cava or thoracic aorta; (4) transient ventricular ischaemia, and (5) neurally induced AF. Low level activity (ranging from 0 to 2.7 Hz) generated by 92 neurons was identified in basal states, activities that displayed functional interconnectivity. The majority (56%) of IC neurons so identified received indirect central inputs (vagus alone: 25%; stellate ganglion alone: 27%; both: 48%). Fifty per cent transduced the cardiac milieu responding to multimodal stressors applied to the great vessels or heart. Fifty per cent of IC neurons exhibited cardiac cycle periodicity, with activity occurring primarily in late diastole into isovolumetric contraction. Cardiac-related activity in IC neurons was primarily related to direct cardiac mechano-sensory inputs and indirect autonomic efferent inputs. In response to mediastinal nerve stimulation, most IC neurons became excessively activated; such network behaviour preceded and persisted throughout AF. It was concluded that stochastic interactions occur among IC local circuit neuronal populations in the control of regional cardiac function. Modulation of IC local circuit neuronal recruitment may represent a novel approach for the treatment of cardiac disease, including atrial arrhythmias. PMID:23818689

  8. A bio-inspired glucose controller based on pancreatic β-cell physiology.

    Science.gov (United States)

    Herrero, Pau; Georgiou, Pantelis; Oliver, Nick; Johnston, Desmond G; Toumazou, Christofer

    2012-05-01

    Control algorithms for closed-loop insulin delivery in type 1 diabetes have been mainly based on control engineering or artificial intelligence techniques. These, however, are not based on the physiology of the pancreas but seek to implement engineering solutions to biology. Developments in mathematical models of the β-cell physiology of the pancreas have described the glucose-induced insulin release from pancreatic β cells at a molecular level. This has facilitated development of a new class of bio-inspired glucose control algorithms that replicate the functionality of the biological pancreas. However, technologies for sensing glucose levels and delivering insulin use the subcutaneous route, which is nonphysiological and introduces some challenges. In this article, a novel glucose controller is presented as part of a bio-inspired artificial pancreas. A mathematical model of β-cell physiology was used as the core of the proposed controller. In order to deal with delays and lack of accuracy introduced by the subcutaneous route, insulin feedback and a gain scheduling strategy were employed. A United States Food and Drug Administration-accepted type 1 diabetes mellitus virtual population was used to validate the presented controller. Premeal and postmeal mean ± standard deviation blood glucose levels for the adult and adolescent populations were well within the target range set for the controller [(70, 180) mg/dl], with a percent time in range of 92.8 ± 7.3% for the adults and 83.5 ± 14% for the adolescents. This article shows for the first time very good glucose control in a virtual population with type 1 diabetes mellitus using a controller based on a subcellular β-cell model. © 2012 Diabetes Technology Society.

  9. Where have the organizers gone? - The growth control system as a foundation of physiology.

    Science.gov (United States)

    Li, Zhimin; Shang, Charles

    2017-01-01

    A model of growth control system suggests that the organizers in embryogenesis continue to exist and partially retain their function after embryogenesis. The organizers are the macroscopic singular points of the morphogen gradient and bioelectric fields. They have higher metabolic rate, higher density of gap junctions and stem cells than the surrounding tissue. The growth control model predicts that the organizers are likely to exist at the extreme points of surface or interface curvature of the body. Changes in bioelectric field at organizers precede the morphological and anatomical changes in morphogenesis and pathogenesis. Subtle perturbations at organizers can cause long lasting systemic effects. These features of organizers can be used for diagnostic and therapeutic purposes such as regenerative medicine. There is increasing evidence that acupuncture points are likely to have originated from organizers in embryogenesis. Many corollaries and predictions of the growth control model have been independently confirmed in developmental biology, physiology, as well as basic and clinical acupuncture research. This model set the first example of a truly integrative biological basis of acupuncture and conventional biomedical sciences which has met the gold standard of science with multiple confirmed predictions in both fields. The growth control system is embedded in various physiological systems and is part of the foundation of physiology and pathophysiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Feedforward Control of a 3-D Physiological Articulatory Model for Vowel Production

    Institute of Scientific and Technical Information of China (English)

    FANG Qiang; Akikazu Nishikido; Jianwu Dang

    2009-01-01

    A three-dimensional (3-D) physiological articulatory model was developed to account for the bio-mechanical properties of the speech organs in speech production. Control of the model to investigate the mechanism of speech production requires an efficient control module to estimate muscle activation patterns, which is used to manipulate the 3-D physiological arUculatory model, according to the desired articulatory posture. For this purpose, a feedforward control strategy was developed by mapping the articulatory target to the corresponding muscle activation pattern via the intrinsic representation of vowel articulation. In this process, the articulatory postures are first mapped to the corresponding intrinsic representations; then, the articulatory postures are clustered in the intrinsic representations space and a nonlinear function is ap-proximated for each cluster to map the intrinsic representation of vowel articulation to the muscle activation pattern by using general regression neural networks (GRNN). The results show that the feedforward control module is able to manipulate the 3-D physiological articulatory model for vowel production with high accu-racy both acoustically and articulatodly.

  11. Patient subgroup analyses of the treatment effect of subcutaneous interferon beta-1a on development of multiple sclerosis in the randomized controlled REFLEX study

    NARCIS (Netherlands)

    Freedman, M.S.; De Stefano, N.; Barkhof, F.; Polman, C.H.; Comi, G.; Uitdehaag, B.M.J.; Casset-Semanaz, F.; Hennessy, B.; Lehr, L.; Stubinski, B.; Jack, D.L.; Kappos, L.

    2014-01-01

    The REFLEX study (NCT00404352) established that subcutaneous (sc) interferon (IFN) β-1a reduced the risks of McDonald MS (2005 criteria) and clinically definite multiple sclerosis (CDMS) in patients with a first clinical demyelinating event suggestive of MS. The aim of this subgroup analysis was to

  12. On-line estimation of physiological states for monitoring and control of bioprocesses

    Directory of Open Access Journals (Sweden)

    Velislava N Lyubenova

    2017-01-01

    Full Text Available An approach for monitoring of main physiological states of a class processes is proposed. This class is characterized by production and consumption of intermediate metabolite related to target product. The balance between these two phenomena is considered as key parameter for recognizing the process physiological states. A general structure of cascade software sensor of the key parameter is derived and applied for process monitoring and control. Two type processes are considered as case study. The first one is mono culture for simultaneous saccharification and fermentation of starch to ethanol by Saccharomyces cerevisiae and the second one is mixed culture for biopolymer production by L. delbrulckii and R. Eutropha. The good properties of the proposed monitoring and control schemes are demonstrated by simulation investigations.

  13. Controle no trabalho: uma reflexão sobre antigas e novas formas de controle e suas conseqüências sobre os trabalhadores Control of work: old and new approaches and effects on workers

    Directory of Open Access Journals (Sweden)

    Magali Costa Guimarães

    2006-03-01

    Full Text Available O controle no trabalho tem se constituído em tema de estudo e foco de preocupação por parte de pesquisadores ligados a diferentes áreas do conhecimento (administração, ergonomia, engenharia, psicologia, medicina, etc.. Trata-se de um assunto nuclear, principalmente quando se pensa na centralidade do trabalho nos dias atuais e na sua importância para a construção da identidade. As transformações ocorridas no mundo do trabalho apontam para novas formas de controle, que afetam os indivíduos em seu bem-estar físico, cognitivo e afetivo. É com base nesses pressupostos que este artigo tem como objetivo realizar uma reflexão sobre as diferentes formas de controle presentes no contexto organizacional, por meio de uma análise histórica, buscando compreender o surgimento e evolução do controle no processo de produção, bem como de uma revisão de pesquisas que apontam as conseqüências da perda ou ausência de controle no trabalho. Parte-se, assim, de uma revisão teórico-conceitual para, num segundo momento, apresentar os resultados desses estudos.Control of work has been the subject of study and concern by researchers in areas such as administration, ergonomics, engineering, psychology and medicine. It is a core issue especially in view of the central importance of work today and it's role in building identity. Transformations in the working world point to new forms of control affecting the individual and his physical, cognitive and affective well being. Different forms of control present in the organizational context were analyzed historically. An understanding of the appearance and evolution of control in the production process was sought as well as evidence of the consequences of a loss or absence of control of work. These results were presented after an initial theoretical and conceptual review.

  14. Multisensory Control of Stabilization Reflexes

    Science.gov (United States)

    2012-08-22

    Longden, who works on energy efficient, state- dependent coding of self-motion information (see below). Kit is now funded from another grant with...in flying insects and their flight performance – a ‘ Neurobio -Engineering’ approach.” [Funding for work in my lab until end of September 2013...efficient lift production due to energy storage in the cuticle, and finally (e) the periodic volume changes of the tracheal system that provides

  15. Metabolomics of Ramadan fasting: an opportunity for the controlled study of physiological responses to food intake.

    Science.gov (United States)

    Mathew, Sweety; Krug, Susanne; Skurk, Thomas; Halama, Anna; Stank, Antonia; Artati, Anna; Prehn, Cornelia; Malek, Joel A; Kastenmüller, Gabi; Römisch-Margl, Werner; Adamski, Jerzy; Hauner, Hans; Suhre, Karsten

    2014-06-06

    High-throughput screening techniques that analyze the metabolic endpoints of biological processes can identify the contributions of genetic predisposition and environmental factors to the development of common diseases. Studies applying controlled physiological challenges can reveal dysregulation in metabolic responses that may be predictive for or associated with these diseases. However, large-scale epidemiological studies with well controlled physiological challenge conditions, such as extended fasting periods and defined food intake, pose logistic challenges. Culturally and religiously motivated behavioral patterns of life style changes provide a natural setting that can be used to enroll a large number of study volunteers. Here we report a proof of principle study conducted within a Muslim community, showing that a metabolomics study during the Holy Month of Ramadan can provide a unique opportunity to explore the pre-prandial and postprandial response of human metabolism to nutritional challenges. Up to five blood samples were obtained from eleven healthy male volunteers, taken directly before and two hours after consumption of a controlled meal in the evening on days 7 and 26 of Ramadan, and after an over-night fast several weeks after Ramadan. The observed increases in glucose, insulin and lactate levels at the postprandial time point confirm the expected physiological response to food intake. Targeted metabolomics further revealed significant and physiologically plausible responses to food intake by an increase in bile acid and amino acid levels and a decrease in long-chain acyl-carnitine and polyamine levels. A decrease in the concentrations of a number of phospholipids between samples taken on days 7 and 26 of Ramadan shows that the long-term response to extended fasting may differ from the response to short-term fasting. The present study design is scalable to larger populations and may be extended to the study of the metabolic response in defined patient

  16. Reflex epileptic mechanisms in humans: Lessons about natural ictogenesis.

    Science.gov (United States)

    Wolf, Peter

    2017-06-01

    The definition of reflex epileptic seizures is that specific seizure types can be triggered by certain sensory or cognitive stimuli. Simple triggers are sensory (most often visual, more rarely tactile or proprioceptive; simple audiogenic triggers in humans are practically nonexistent) and act within seconds, whereas complex triggers like praxis, reading and talking, and music are mostly cognitive and work within minutes. The constant relation between a qualitatively, often even quantitatively, well-defined stimulus and a specific epileptic response provides unique possibilities to investigate seizure generation in natural human epilepsies. For several reflex epileptic mechanisms (REMs), this has been done. Reflex epileptic mechanisms have been reported less often in focal lesional epilepsies than in idiopathic "generalized" epilepsies (IGEs) which are primarily genetically determined. The key syndrome of IGE is juvenile myoclonic epilepsy (JME), where more than half of the patients present reflex epileptic traits (photosensitivity, eye closure sensitivity, praxis induction, and language-induced orofacial reflex myocloni). Findings with multimodal investigations of cerebral function concur to indicate that ictogenic mechanisms in IGEs largely (ab)use preexisting functional anatomic networks (CNS subsystems) normally serving highly complex physiological functions (e.g., deliberate complex actions and linguistic communication) which supports the concept of system epilepsy. Whereas REMs in IGEs, thus, are primarily function-related, in focal epilepsies, they are primarily localization-related. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic". Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Reflexive Dressing: Rethinking Retro

    Directory of Open Access Journals (Sweden)

    Stella North

    2016-03-01

    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.

  18. Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

    Science.gov (United States)

    Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

    2010-01-01

    Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

  19. System and method for leveraging human physiological traits to control microprocessor frequency

    Energy Technology Data Exchange (ETDEWEB)

    Shye, Alex; Pan, Yan; Scholbrock, Benjamin; Miller, J. Scott; Memik, Gokhan; Dinda, Peter A; Dick, Robert P

    2014-03-25

    A system and method for leveraging physiological traits to control microprocessor frequency are disclosed. In some embodiments, the system and method may optimize, for example, a particular processor-based architecture based on, for example, end user satisfaction. In some embodiments, the system and method may determine, for example, whether their users are satisfied to provide higher efficiency, improved reliability, reduced power consumption, increased security, and a better user experience. The system and method may use, for example, biometric input devices to provide information about a user's physiological traits to a computer system. Biometric input devices may include, for example, one or more of the following: an eye tracker, a galvanic skin response sensor, and/or a force sensor.

  20. AMPUTATION AND REFLEX SYMPATHETIC DYSTROPHY

    NARCIS (Netherlands)

    GEERTZEN, JHB; EISMA, WH

    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

  1. [Reflex seizures, cinema and television].

    Science.gov (United States)

    Olivares-Romero, Jesús

    2015-12-16

    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.

  2. Accelerated aging and controlled deterioration for the determination of the physiological potential of onion seeds

    Directory of Open Access Journals (Sweden)

    Rodo Angelica Brod

    2003-01-01

    Full Text Available International research on vegetable seed vigor is not at the same level attained for grain crops species. This study was conducted to identify reliable procedures for the accelerated aging and controlled deterioration tests to rank onion (Allium cepa L. seed lots according to their physiological potential. Six seed lots of the cultivars Aurora and Petroline were evaluated in the laboratory for germination, first count, seedling vigor classification, traditional and saturated salt accelerated aging (41masculineC / 48 and 72 h, controlled deterioration (24% of water / 45masculineC / 24 h and seedling emergence tests. Seed moisture content after the saturated salt accelerated aging test was lower and uniform, which is considered an important advantage in comparison to the traditional procedure. The saturated salt accelerated aging (41masculineC / 48 and 72 h and controlled deterioration (moisture content adjusted to 24% / 45masculineC / 24 h tests were the best procedures to assess the physiological potential of onion seeds, and are indicated for use in quality control programs.

  3. Physiological regulation through learnt control of appetites by contingencies among signals from external and internal environments.

    Science.gov (United States)

    Booth, David A

    2008-11-01

    As reviewed by [Cooper, S. J. (2008). From Claude Bernard to Walter Cannon: emergence of the concept of homeostasis. Appetite 51, 419-27.] Claude Bernard's idea of stabilisation of bodily states, as realised in Walter B. Cannon's conception of homeostasis, took mathematical form during the 1940s in the principle that externally originating disturbance of a physiological parameter can feed an informative signal around the brain to trigger counteractive processes--a corrective mechanism known as negative feedback, in practice reliant on feedforward. Three decades later, enough was known of the physiology and psychology of eating and drinking for calculations to show how experimentally demonstrated mechanisms of feedforward that had been learnt from negative feedback combine to regulate exchanges of water and energy between the body and the surroundings. Subsequent systemic physiology, molecular neuroscience and experimental psychology, however, have been traduced by a misconception that learnt controls of intake are 'non-homeostatic', the myth of biological 'set points' and an historic failure to address evidence for the ingestion-adapting information-processing mechanisms on which an operationally integrative theory of eating and drinking relies.

  4. Numerical Oscillations Analysis for Nonlinear Delay Differential Equations in Physiological Control Systems

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2012-01-01

    Full Text Available This paper deals with the oscillations of numerical solutions for the nonlinear delay differential equations in physiological control systems. The exponential θ-method is applied to p′(t=β0ωμp(t−τ/(ωμ+pμ(t−τ−γp(t and it is shown that the exponential θ-method has the same order of convergence as that of the classical θ-method. Several conditions under which the numerical solutions oscillate are derived. Moreover, it is proven that every nonoscillatory numerical solution tends to positive equilibrium of the continuous system. Finally, the main results are illustrated with numerical examples.

  5. Autogenic Feedback Training Exercise: Controlling Physiological Responses to Mitigate Motion Sickness

    Science.gov (United States)

    Walton, Nia; Spencer, Telissa; Cowings, Patricia; Toscano, William B.

    2018-01-01

    During space travel approximately 50 of the crew experience symptoms of motion sickness that can range from mild forms of nausea or dizziness to severe malaise and vomiting1. Developing an effective treatment for these symptoms has become a priority of the National Aeronautics and Space Administration (NASA). Autogenic-Feedback Training Exercise (AFTE) is a nonpharmacological countermeasure for mitigating motion sickness. It involves training subjects to control physiological responses in high stress environments2. The primary goal of this experiment is to evaluate the effectiveness of AFTE for increasing tolerance to motion sickness in high stress environments.

  6. Overview: clinical and physiological comparison of meditation with other self-control strategies.

    Science.gov (United States)

    Shapiro, D H

    1982-03-01

    In 1977 the American Psychiatric Association called for a critical examination of the clinical effectiveness of meditation. The author provides a review of the literature bearing on clinical and physiological comparisons of meditation with other self-control strategies. He begins by providing a definition of mediation and then cites the literature comparing mediation with such self-regulation strategies as biofeedback, hypnosis, and progressive relaxation. He pays particular attention to the "uniqueness" of mediation as a clinical intervention strategy a well as the adverse effects of meditation. Finally, he offers suggestions and guidelines for future research.

  7. Reflex responses of lip muscles in young and older women.

    Science.gov (United States)

    Wohlert, A B

    1996-06-01

    The perioral reflex in response to innocuous mechanical stimulation of the lip vermilion was studied in 20 young and 20 older women. Responses to stimuli at the right and left sides of both the upper and lower lips were recorded. Results show significant specificity of response, especially for upper lip sites. Reflex response at the site of stimulation was greatest in amplitude and shortest in latency, followed by response at sites ipsilateral to the site of stimulation. Younger subjects showed greater localizing tendency than older subjects. Stimulation was significantly less likely to produce a reflex response in the older group. When reflex responses did occur, they were significantly lower in amplitude and longer in latency than the responses of the younger group. Nonetheless, reflex responses were common in both groups, with responses at the site of stimulation occurring 78% of the time in older women and 90% of the time in younger women. Every participant showed at least one reflex response to lip stimulation. Results suggest decreasing complexity of synaptic drive to the perioral system in old age but also show that reflexive response does not deteriorate completely, remaining an available element for motor control in normal older women.

  8. Motivational intensity modulates the effects of positive emotions on set shifting after controlling physiological arousal.

    Science.gov (United States)

    Zhou, Ya; Siu, Angela F Y

    2015-12-01

    Recent research on the construct of emotion suggests the integration of a motivational dimension into the traditional two-dimension (subjective valence and physiological arousal) model. The motivational intensity of an emotional state should be taken into account while investigating the emotion-cognition relationship. This study examined how positive emotional states varying in motivational intensity influenced set shifting, after controlling the potential confounding impacts of physiological arousal. In Experiment 1, 155 volunteers performed a set-shifting task after being randomly assigned to five states: high- vs. low-motivating positive affect (interest vs. serenity), high- vs. low-motivating negative affect (disgust vs. anxiety), and neutral state. Eighty-five volunteers participated in Experiment 2, which further examined the effects of higher vs. lower degree of interest. Both experiments measured and compared participants' physiological arousal (blood pressure and pulse rate) under the normal and experimental conditions as the covariate. Results showed no difference in switching performance between the neutral and serenity groups. As compared with the neutral state, the high-motivating positive affect significantly increased set-switching reaction time costs, but reduced error rate costs; the higher the motivational intensity, the greater the time-costs impairment. This indicates a role of the high-motivating positive affect in regulating the balance between the flexible and stable cognitive control. Motivational intensity also modulated the effects of negative emotional states, i.e., disgust caused a larger increase in time costs than anxiety. Further exploration into neurobiological mechanisms that may mediate the emotional effects on set shifting is warranted. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  9. The BUMP model of response planning: intermittent predictive control accounts for 10 Hz physiological tremor.

    Science.gov (United States)

    Bye, Robin T; Neilson, Peter D

    2010-10-01

    Physiological tremor during movement is characterized by ∼10 Hz oscillation observed both in the electromyogram activity and in the velocity profile. We propose that this particular rhythm occurs as the direct consequence of a movement response planning system that acts as an intermittent predictive controller operating at discrete intervals of ∼100 ms. The BUMP model of response planning describes such a system. It forms the kernel of Adaptive Model Theory which defines, in computational terms, a basic unit of motor production or BUMP. Each BUMP consists of three processes: (1) analyzing sensory information, (2) planning a desired optimal response, and (3) execution of that response. These processes operate in parallel across successive sequential BUMPs. The response planning process requires a discrete-time interval in which to generate a minimum acceleration trajectory to connect the actual response with the predicted future state of the target and compensate for executional error. We have shown previously that a response planning time of 100 ms accounts for the intermittency observed experimentally in visual tracking studies and for the psychological refractory period observed in double stimulation reaction time studies. We have also shown that simulations of aimed movement, using this same planning interval, reproduce experimentally observed speed-accuracy tradeoffs and movement velocity profiles. Here we show, by means of a simulation study of constant velocity tracking movements, that employing a 100 ms planning interval closely reproduces the measurement discontinuities and power spectra of electromyograms, joint-angles, and angular velocities of physiological tremor reported experimentally. We conclude that intermittent predictive control through sequential operation of BUMPs is a fundamental mechanism of 10 Hz physiological tremor in movement. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Single Canonical Model of Reflexive Memory and Spatial Attention

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26493949

  11. Single Canonical Model of Reflexive Memory and Spatial Attention.

    Science.gov (United States)

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

    2015-10-23

    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.

  12. Effects of music on physiological and behavioral responses of premature infants: a randomized controlled trial.

    Science.gov (United States)

    Alipour, Zahra; Eskandari, Narges; Ahmari Tehran, Hoda; Eshagh Hossaini, Seyed Kamal; Sangi, Sareh

    2013-08-01

    Despite persuasive theories about the beneficial effects of music and singing in developmental care for premature infants, few small studies are available in this regard. We conducted this study to investigate the physiological and behavioral responses of premature infants to recorded lullaby music and silence. In a randomized controlled trial, 90 premature infants in the neonatal care unit of a hospital in Qom (Iran) were randomly allocated to intervention (lullaby and silence) or control groups. Lullaby music was played via headphones at a volume of 50-60 dB. In the silence group, headphones were placed on the infants' ears while no music was played. The three groups were surveyed for physiological responses including oxygen saturation, respiratory and heart rates, and behavioral states every five minutes before, during, and after the intervention. The three groups were not significantly different in terms of mean values of respiratory and heart rates, oxygen saturation, and behavioral states of infants. Similarly, no significant within group differences in respiratory and heart rates, oxygen saturation, and behavioral states were observed at different times. Our findings did not support the beneficial effects of music for premature infants. However, music is a noninvasive, non-pharmaceutical, and relatively low-cost intervention that can be implemented at infants' bedside. Thus further research is warranted to determine whether the effects noted in previous studies can be consistently replicated in diverse settings and with diverse groups of preterm infants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Omissões legislativas inconstitucionais: reflexões acerca do seu correto delineamento teórico e da legitimidade democrática do seu controle

    OpenAIRE

    João Paulo de Aguiar Santos

    2013-01-01

    A presente dissertação objetiva, a partir principalmente de reflexões abstratas, fornecer elementos capazes de fomentar um coerente questionamento em relação à formulação teórica dominante no que se refere ao estudo da inconstitucionalidade por omissão. Busca-se evidenciar o contexto histórico e jurídico em que o instituto foi desenvolvido para, em seguida, defender a necessidade de se partir para um novo delineamento teórico das circunstâncias aptas a caracterizarem a ocorrência de uma omiss...

  14. The effects of static friction and backlash on extended physiological proprioception control of a powered prosthesis.

    Science.gov (United States)

    Farrell, Todd R; Weir, Richard F; Heckathorne, Craig W; Childress, Dudley S

    2005-01-01

    In general, externally powered prostheses do not provide proprioceptive feedback and thus require the user to rely on cognitively expensive visual feedback to effectively control the prosthesis. Applying the concept of extended physiological proprioception (EPP) to externally powered prostheses provides direct feedback to the user's proprioceptive system regarding the position, velocity, and forces applied to the prosthesis. However, electric elbows with EPP controllers developed at the Northwestern University Prosthetics Research Laboratory have exhibited unexplained "jerky" behavior in both clinical fittings and bench-top operation. In addition, the development of limit cycles, a specific type of constant-amplitude oscillation, had been observed in bench-top use of these elbows. Backlash and static friction within the EPP system were found to be primarily responsible for the development of limit cycles. Reducing static friction and backlash improved the system's performance. These results suggest that to most effectively implement EPP, prosthesis manufacturers should design prosthetic components that minimize static friction and backlash.

  15. Gravity Plant Physiology Facility (GPPF) Team in the Spacelab Payload Operations Control Center (SL

    Science.gov (United States)

    1992-01-01

    The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Gravity Plant Physiology Facility (GPPF) team in the SL POCC during the IML-1 mission.

  16. 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.

    Science.gov (United States)

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

    2014-09-15

    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.

  17. Management of Reflex Anoxic Seizures

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-10-01

    Full Text Available Investigators at the Roald Dahl EEG Unit, Alder Hey Children’s NHS Foundation, Liverpool, UK, review the definition, pathophysiology, clinical presentation, and management of reflex anoxic seizures (RAS in children.

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

    OpenAIRE

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

    2015-01-01

    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...

  19. Physiological monitoring and control in hemodialysis: state of the art and outlook.

    Science.gov (United States)

    Kraemer, Matthias

    2006-09-01

    Medical devices for monitoring and feedback control of physiological parameters of the dialysis patient were introduced in the early 1990s. They have a wide range of applications, aiming at increasing the safety and ensuring the efficiency of the treatment, and at an improved restoration of physiological conditions, leading to an overall reduction in morbidity and mortality. Such devices include sensors for the measurement of temperature, optical parameters and sound speed in blood, and electrical characteristics of the human body, and other parameters. Essential for the development of these devices is a detailed understanding of the pathophysiological background of a therapeutical problem. There is still a large potential to introduce new devices for further therapy improvement and automation. Also, the size of the hemodialysis market appears attractive; however, a new product has to meet several specific requirements in order to also become commercially successful. This review describes the therapeutic and technical principles of several available devices, reports on concepts for possible future devices, and presents a short overview on the market environment.

  20. Otolith and canal reflexes in human standing

    Science.gov (United States)

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

    2005-01-01

    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

  1. [New theory of holistic integrative physiology and medicine. I: New insight of mechanism of control and regulation of breathing].

    Science.gov (United States)

    Sun, Xing-guo

    2015-07-01

    The modern systemic physiology, based on limit-understand functional classification, has significant limitation and one-sidedness. Human being is organic; we should approach the mechanism of control and regulation of breathing integrating all the systems. We use new theory of holistic integrative physiology and medicine to explain the mechanism of control and regulation of breathing. Except the mean level information, the up-down "W" waveform information of arterial blood gas (ABG) is core signal to control and regulate breathing. In order to do so, we must integrate all systems together. New theory will help to explain some unanswered questions in physiology and medicine, for example: fetal does not breathing; how first breath generate; how respiratory rhythm and frequency generate, etc. Breathing is the sign of life. Mechanism of control and regulation of breathing has to integrate respiration, circulation, nerves, metabolism, exercise, sleep and digestion, absorption and elimination and etc altogether.

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

    Directory of Open Access Journals (Sweden)

    Yuki Tanaka

    2017-10-01

    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.

  3. Physiological closed-loop control in intelligent oxygen therapy: A review.

    Science.gov (United States)

    Sanchez-Morillo, Daniel; Olaby, Osama; Fernandez-Granero, Miguel Angel; Leon-Jimenez, Antonio

    2017-07-01

    Oxygen therapy has become a standard care for the treatment of patients with chronic obstructive pulmonary disease and other hypoxemic chronic lung diseases. In current systems, manually continuous adjustment of O 2 flow rate is a time-consuming task, often unsuccessful, that requires experienced staff. The primary aim of this systematic review is to collate and report on the principles, algorithms and accuracy of autonomous physiological close-loop controlled oxygen devices as well to present recommendations for future research and studies in this area. A literature search was performed on medical database MEDLINE, engineering database IEEE-Xplore and wide-raging scientific databases Scopus and Web of Science. A narrative synthesis of the results was carried out. A summary of the findings of this review suggests that when compared to the conventional manual practice, the closed-loop controllers maintain higher saturation levels, spend less time below the target saturation, and save oxygen resources. Nonetheless, despite of their potential, autonomous oxygen therapy devices are scarce in real clinical applications. Robustness of control algorithms, fail-safe mechanisms, limited reliability of sensors, usability issues and the need for standardized evaluating methods of assessing risks can be among the reasons for this lack of matureness and need to be addressed before the wide spreading of a new generation of automatic oxygen devices. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. [H reflex in patients with spastic quadriplegia].

    Science.gov (United States)

    Miyama, Sahoko; Arimoto, Kiyoshi; Kimiya, Satoshi

    2009-01-01

    Hoffmann reflex (H reflex) is an electrically elicited spinal monosynaptic reflex. H reflex was examined in 18 patients with spastic quadriplegia who had perinatal or postnatal problems. H reflex was elicitable in 11 patients for the abductor pollicis brevis (61.1%), 10 for the abductor digiti minimi (55.6%) and 16 for the abductor hallucis (88.9%). Because the abductor pollicis brevis and the abductor digiti minimi do not exhibit H reflex in normal subjects, it was suggested that the excitability of alpha motor neurons innervating these muscles was increased. H reflex was not detected for the extensor digitorum brevis in any patients, indicating the difference in the excitability among alpha motor neurons. In some patients, H reflex did not disappear under supramaximal stimuli. We conclude that the mechanism of evolution of H reflex in patients with spastic quadriplegia is different from that in normal subjects.

  5. Role of spinal metabotropic glutamate receptor 5 in pudendal inhibition of the nociceptive bladder reflex in cats.

    Science.gov (United States)

    Reese, Jeremy N; Rogers, Marc J; Xiao, Zhiying; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-04-15

    This study examined the role of spinal metabotropic glutamate receptor 5 (mGluR5) in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in the inhibtion of this reflex by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats after spinal cord transection at the T9/T10 level, intravesical infusion of 0.25% acetic acid irritated the bladder, activated nociceptive C-fiber afferents, and induced spinal reflex bladder contractions of low amplitude (reflexes were responsible for a major component of the contractions. This study shows that spinal mGluR5 plays an important role in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in pudendal inhibition of this spinal reflex. Copyright © 2015 the American Physiological Society.

  6. Reflexive fatherhood in everyday life

    DEFF Research Database (Denmark)

    Westerling, Allan

    2015-01-01

    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 intimacy...... in their relationships with their children. Moreover, it discusses how fathers’ relatedness reflects individualisation and detraditionalisation. It is argued that reflexive modernisation entails subjective orientations that enable novel pathways to intimacy in contemporary father–child relationships. Through...... this analysis and discussion, the article offers a way to understand the complexities of fathering in everyday life from the perspective of fathers....

  7. Outside home. Notes on reflexivity

    Directory of Open Access Journals (Sweden)

    Mara Clemente

    2017-01-01

    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.

  8. Educating the Reflexive Practitioner

    Directory of Open Access Journals (Sweden)

    Marc J. Neveu

    2012-09-01

    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.

  9. Neurodevelopmental Reflex Testing in Neonatal Rat Pups.

    Science.gov (United States)

    Nguyen, Antoinette T; Armstrong, Edward A; Yager, Jerome Y

    2017-04-24

    Neurodevelopmental reflex testing is commonly used in clinical practice to assess the maturation of the nervous system. Neurodevelopmental reflexes are also referred to as primitive reflexes. They are sensitive and consistent with later outcomes. Abnormal reflexes are described as an absence, persistence, reappearance, or latency of reflexes, which are predictive indices of infants that are at high risk for neurodevelopmental disorders. Animal models of neurodevelopmental disabilities, such as cerebral palsy, often display aberrant developmental reflexes, as would be observed in human infants. The techniques described assess a variety of neurodevelopmental reflexes in neonatal rats. Neurodevelopmental reflex testing offers the investigator a testing method that is not otherwise available in such young animals. The methodology presented here aims to assist investigators in examining developmental milestones in neonatal rats as a method of detecting early-onset brain injury and/or determining the effectiveness of therapeutic interventions. The methodology presented here aims to provide a general guideline for investigators.

  10. Reflex muscle contraction in anterior shoulder instability.

    Science.gov (United States)

    Wallace, D A; Beard, D J; Gill, R H; Eng, B; Carr, A J

    1997-01-01

    Reduced proprioception may contribute to recurrent anterior shoulder instability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activated pneumatic cylinder and surface electromyography electrodes; the contralateral normal shoulder was used as a control. The latency between onset of movement and the detection of muscle contraction was used as an index of proprioception. No significant difference in muscle contraction latency was detected between the stable and unstable shoulders, suggesting that there was no significant defect in muscular reflex activity. This study does not support the use proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder instability.

  11. Animal thermoregulation: a review of insulation, physiology and behaviour relevant to temperature control in buildings.

    Science.gov (United States)

    McCafferty, D J; Pandraud, G; Gilles, J; Fabra-Puchol, M; Henry, P-Y

    2017-12-28

    Birds and mammals have evolved many thermal adaptations that are relevant to the bioinspired design of temperature control systems and energy management in buildings. Similar to many buildings, endothermic animals generate internal metabolic heat, are well insulated, regulate their temperature within set limits, modify microclimate and adjust thermal exchange with their environment. We review the major components of animal thermoregulation in endothermic birds and mammals that are pertinent to building engineering, in a world where climate is changing and reduction in energy use is needed. In animals, adjustment of insulation together with physiological and behavioural responses to changing environmental conditions fine-tune spatial and temporal regulation of body temperature, while also minimizing energy expenditure. These biological adaptations are characteristically flexible, allowing animals to alter their body temperatures to hourly, daily, or annual demands for energy. They exemplify how buildings could become more thermally reactive to meteorological fluctuations, capitalising on dynamic thermal materials and system properties. Based on this synthesis, we suggest that heat transfer modelling could be used to simulate these flexible biomimetic features and assess their success in reducing energy costs while maintaining thermal comfort for given building types.

  12. Soleus stretch reflex during cycling

    DEFF Research Database (Denmark)

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

    2001-01-01

    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. The reflexive case study method

    DEFF Research Database (Denmark)

    Rittenhofer, Iris

    2015-01-01

    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...

  14. A technological and physiological integrated approach for appetite control : from identification of novel biomarkers to development of new functional ingredients

    NARCIS (Netherlands)

    Mennella, I.

    2015-01-01

    A technological and physiological integrated approach for appetite control.

    From identification of novel biomarkers to development of new functional ingredients.

    Human dietary behaviour is driven by homeostatic, hedonic and environmental factors.

  15. ESO Reflex: a graphical workflow engine for data reduction

    Science.gov (United States)

    Hook, Richard; Ullgrén, Marko; Romaniello, Martino; Maisala, Sami; Oittinen, Tero; Solin, Otto; Savolainen, Ville; Järveläinen, Pekka; Tyynelä, Jani; Péron, Michèle; Ballester, Pascal; Gabasch, Armin; Izzo, Carlo

    ESO Reflex is a prototype software tool that provides a novel approach to astronomical data reduction by integrating a modern graphical workflow system (Taverna) with existing legacy data reduction algorithms. Most of the raw data produced by instruments at the ESO Very Large Telescope (VLT) in Chile are reduced using recipes. These are compiled C applications following an ESO standard and utilising routines provided by the Common Pipeline Library (CPL). Currently these are run in batch mode as part of the data flow system to generate the input to the ESO/VLT quality control process and are also exported for use offline. ESO Reflex can invoke CPL-based recipes in a flexible way through a general purpose graphical interface. ESO Reflex is based on the Taverna system that was originally developed within the UK life-sciences community. Workflows have been created so far for three VLT/VLTI instruments, and the GUI allows the user to make changes to these or create workflows of their own. Python scripts or IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available. Taverna is intended for use with web services and experiments using ESO Reflex to access Virtual Observatory web services have been successfully performed. ESO Reflex is the main product developed by Sampo, a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal was to look into the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Sampo concluded early in 2008. This contribution will describe ESO Reflex and show several examples of its use both locally and using Virtual Observatory remote web services. ESO Reflex is expected to be released to the community in early 2009.

  16. Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

    Science.gov (United States)

    Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

    2016-12-01

    Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

  17. Climatic and physiological controls on the stable isotope composition of modern and ancient Cupressaceae

    Science.gov (United States)

    Zinniker, D.; Tipple, B.; Pagani, M.

    2007-12-01

    Unique and abundant secondary metabolites found in waxes and resins of the Callitroid, Cupressoid, and Taxodioid clades of the Cupressaceae family can be identified and quantified in complex mixtures of sedimentary organic compounds. This unusual feature makes it possible to study relatively simple (taxon-specific) isotope systems back in time across the broad array of environments in which these conifers are found. Work on these systems can potentially provide both robust paleoenvironmental proxies (i.e. for source water δD and growing season relative humidity) and quantitative probes into the ecophysiology of these plants in modern and ancient environments. Our research focuses on three genera representing environmental end-members of Cupressaceae - Juniperus, Thuja, and Chamaecyparis - (1) across geographic and environmental gradients in the field, and (2) in specific Holocene and late Pleistocene environmental records. The latter research focuses on peat cores from New England and Oregon and fossil packrat middens from the southwestern United States. Modern transects highlight the sensitivity of Cupressaceae to climatic variables. These include both variables during growth (relative humidity, soil moisture, etc.) and variables affecting seasonal and diurnal growth rates (temperature, winter precipitation, insolation, microhabitat, etc.). Work on ancient records has demonstrated the sensitivity of these unique taxon-specific archives to both subtle and dramatic climate shifts during the Pleistocene and Holocene. This work will result in an improved understanding of climatic and physiological controls on the stable isotopic composition of modern and ancient Cupressaceae - and by extension, other arborescent gymnosperms and C3 plants - providing a framework for understanding more complexly sourced organic inputs to sediments, coals, and petroleum prior to the advent of C4 plants. This research also has direct implications for stratigraphic stable isotope studies

  18. Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

    Science.gov (United States)

    Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

    2017-05-01

    Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Physiological pseudomyopia.

    Science.gov (United States)

    Jones, R

    1990-08-01

    Objective refraction through plus fogging lenses and base-in prisms revealed that normally accommodation is not completely relaxed when the stimulus to accommodation is zero. The myopic shift in the refractive error due to this focus error of accommodation was defined as physiological pseudomyopia. Two previously established features of accommodation are responsible for this behavior: (1) accommodation acts as a proportional control system for steady-state responses; and (2) the rest focus of accommodation is nonzero. It is proposed that the hyperopic shift in refraction observed in cycloplegia is the result of elimination of physiological pseudomyopia.

  20. Propranolol, but not naloxone, enhances spinal reflex bladder activity and reduces pudendal inhibition in cats.

    Science.gov (United States)

    Rogers, Marc J; Xiao, Zhiying; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-01-01

    This study examined the role of β-adrenergic and opioid receptors in spinal reflex bladder activity and in the inhibition induced by pudendal nerve stimulation (PNS) or tibial nerve stimulation (TNS). Spinal reflex bladder contractions were induced by intravesical infusion of 0.25% acetic acid in α-chloralose-anesthetized cats after an acute spinal cord transection (SCT) at the thoracic T9/T10 level. PNS or TNS at 5 Hz was applied to inhibit these spinal reflex contractions at 2 and 4 times the threshold intensity (T) for inducing anal or toe twitch, respectively. During a cystrometrogram (CMG), PNS at 2T and 4T significantly (P reflex bladder contractions. After administering propranolol (3 mg/kg iv, a β₁/β₂-adrenergic receptor antagonist), the effects of 2T and 4T PNS on bladder capacity were significantly (P reflex bladder contractions or PNS inhibition. At the end of experiments, hexamethonium (10 mg/kg iv, a ganglionic blocker) significantly (P reflex bladder contractions. This study indicates an important role of β₁/β₂-adrenergic receptors in pudendal inhibition and spinal reflex bladder activity. Copyright © 2015 the American Physiological Society.

  1. Increased excitability of spinal pain reflexes and altered frequency-dependent modulation in the dopamine D3-receptor knockout mouse.

    Science.gov (United States)

    Keeler, Benjamin E; Baran, Christine A; Brewer, Kori L; Clemens, Stefan

    2012-12-01

    Frequency-dependent modulation and dopamine (DA) receptors strongly modulate neural circuits in the spinal cord. Of the five known DA receptor subtypes, the D3 receptor has the highest affinity to DA, and D3-mediated actions are mainly inhibitory. Using an animal model of spinal sensorimotor dysfunction, the D3 receptor knockout mouse (D3KO), we investigated the physiological consequences of D3 receptor dysfunction on pain-associated signaling pathways in the spinal cord, the initial integration site for the processing of pain signaling. In the D3KO spinal cord, inhibitory actions of DA on the proprioceptive monosynaptic stretch reflex are converted from depression to facilitation, but its effects on longer-latency and pain-associated reflex responses and the effects of FM have not been studied. Using behavioral approaches in vivo, we found that D3KO animals exhibit reduced paw withdrawal latencies to thermal pain stimulation (Hargreaves' test) over wild type (WT) controls. Electrophysiological and pharmacological approaches in the isolated spinal cord in vitro showed that constant current stimulation of dorsal roots at a pain-associated frequency was associated with a significant reduction in the frequency-dependent modulation of longer-latency reflex (LLRs) responses but not monosynaptic stretch reflexes (MSRs) in D3KO. Application of the D1 and D2 receptor agonists and the voltage-gated calcium-channel ligand, pregabalin, but not DA, was able to restore the frequency-dependent modulation of the LLR in D3KO to WT levels. Thus we demonstrate that nociception-associated LLRs and proprioceptive MSRs are differentially modulated by frequency, dopaminergics and the Ca(2+) channel ligand, pregabalin. Our data suggest a role for the DA D3 receptor in pain modulation and identify the D3KO as a possible model for increased nociception. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Method and Apparatus for Encouraging Physiological Self-Regulation Through Modulation of an Operator's Control Input to a Video Game or Training Simulator

    Science.gov (United States)

    Palsson, Olafur S. (Inventor); Harris, Randall L., Sr. (Inventor); Pope, Alan T. (Inventor)

    2002-01-01

    Apparatus and methods for modulating the control authority (i.e., control function) of a computer simulation or game input device (e.g., joystick, button control) using physiological information so as to affect the user's ability to impact or control the simulation or game with the input device. One aspect is to use the present invention, along with a computer simulation or game, to affect physiological state or physiological self-regulation according to some programmed criterion (e.g., increase, decrease, or maintain) in order to perform better at the game task. When the affected physiological state or physiological self-regulation is the target of self-regulation or biofeedback training, the simulation or game play reinforces therapeutic changes in the physiological signal(s).

  3. Cenotic and physiological control of the radionuclides migration into system soil-plant

    International Nuclear Information System (INIS)

    Kravets, A.P.

    1998-01-01

    Some biological - cenotic and physiological - factors which determine the availability of radionuclides for a plant and the general capacity for the accumulation of pollutants were investigated and analysed. Metabolites of soil microorganisms and especially root excretion of higher plants increase the rate of destruction of solid forms of pollution and enhance the leaching of radionuclides from the solid matrix. The following facts were demonstrated in the conditions of contamination heterogeneity of Chernobyl fallout: (i) During the period of vegetation the plants of different species of f. Poacea, 1 .5 to 2.7-fold increase in the chemical mobility and biological availability of radionuclides; (ii) Additional increase in the concentration of soil microorganisms (micromycetes) leads to enhanced contents of the mobile form of the pollutant in soil and increases the level of accumulation of the radionuclides by higher plants; (iii) Increase in the density of sowing (and competition, respectively) of the different species of the plants also leads to an enhanced availability of the radionuclides and 1 .7 to 2.4- fold increase in the level of accumulation of the radionuclides by the plants. Other aspect of formation of the level of plant pollution include the peculiarities of radionuclide absorption and accumulation by the plant biomass. The effects of a high density of sowing, high level of the watering and gamma irradiation on the changes in the level of radionuclide accumulation and, at the same time, the cation exchange capacity (CEC) of the plant biomass were investigated in the laboratory and in a greenhouse experiment. In parallel, increased CEC and radionuclide accumulation by a factor of 1.5 to 2.7 was demonstrated. These facts suggest that the biological factors are a powerful tool of control of the pollutants availability and accumulation and may be take into account under development of the modern agricultural technology for clear products formation

  4. Physiological control of dual rotary pumps as a biventricular assist device using a master/slave approach.

    Science.gov (United States)

    Stevens, Michael C; Wilson, Stephen; Bradley, Andrew; Fraser, John; Timms, Daniel

    2014-09-01

    Dual rotary left ventricular assist devices (LVADs) can provide biventricular mechanical support during heart failure. Coordination of left and right pump speeds is critical not only to avoid ventricular suction and to match cardiac output with demand, but also to ensure balanced systemic and pulmonary circulatory volumes. Physiological control systems for dual LVADs must meet these objectives across a variety of clinical scenarios by automatically adjusting left and right pump speeds to avoid catastrophic physiological consequences. In this study we evaluate a novel master/slave physiological control system for dual LVADs. The master controller is a Starling-like controller, which sets flow rate as a function of end-diastolic ventricular pressure (EDP). The slave controller then maintains a linear relationship between right and left EDPs. Both left/right and right/left master/slave combinations were evaluated by subjecting them to four clinical scenarios (rest, postural change, Valsalva maneuver, and exercise) simulated in a mock circulation loop. The controller's performance was compared to constant-rotational-speed control and two other dual LVAD control systems: dual constant inlet pressure and dual Frank-Starling control. The results showed that the master/slave physiological control system produced fewer suction events than constant-speed control (6 vs. 62 over a 7-min period). Left/right master/slave control had lower risk of pulmonary congestion than the other control systems, as indicated by lower maximum EDPs (15.1 vs. 25.2-28.4 mm Hg). During exercise, master/slave control increased total flow from 5.2 to 10.1 L/min, primarily due to an increase of left and right pump speed. Use of the left pump as the master resulted in fewer suction events and lower EDPs than when the right pump was master. Based on these results, master/slave control using the left pump as the master automatically adjusts pump speed to avoid suction and increases pump flow

  5. Role of the brain stem in tibial inhibition of the micturition reflex in cats.

    Science.gov (United States)

    Ferroni, Matthew C; Slater, Rick C; Shen, Bing; Xiao, Zhiying; Wang, Jicheng; Lee, Andy; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-08-01

    This study examined the role of the brain stem in inhibition of bladder reflexes induced by tibial nerve stimulation (TNS) in α-chloralose-anesthetized decerebrate cats. Repeated cystometrograms (CMGs) were performed by infusing saline or 0.25% acetic acid (AA) to elicit normal or overactive bladder reflexes, respectively. TNS (5 or 30 Hz) at three times the threshold (3T) intensity for inducing toe movement was applied for 30 min between CMGs to induce post-TNS inhibition or applied during the CMGs to induce acute TNS inhibition. Inhibition was evident as an increase in bladder capacity without a change in amplitude of bladder contractions. TNS applied for 30 min between saline CMGs elicited prolonged (>2 h) poststimulation inhibition that significantly (P reflexes but are not involved in inhibition of normal bladder reflexes. Copyright © 2015 the American Physiological Society.

  6. Pain physiology education improves health status and endogenous pain inhibition in fibromyalgia: a double-blind randomized controlled trial.

    Science.gov (United States)

    Van Oosterwijck, Jessica; Meeus, Mira; Paul, Lorna; De Schryver, Mieke; Pascal, Aurelie; Lambrecht, Luc; Nijs, Jo

    2013-10-01

    There is evidence that education on pain physiology can have positive effects on pain, disability, and catastrophization in patients with chronic musculoskeletal pain disorders. A double-blind randomized controlled trial (RCT) was performed to examine whether intensive pain physiology education is also effective in fibromyalgia (FM) patients, and whether it is able to influence the impaired endogenous pain inhibition of these patients. Thirty FM patients were randomly allocated to either the experimental (receiving pain physiology education) or the control group (receiving pacing self-management education). The primary outcome was the efficacy of the pain inhibitory mechanisms, which was evaluated by spatially accumulating thermal nociceptive stimuli. Secondary outcome measures included pressure pain threshold measurements and questionnaires assessing pain cognitions, behavior, and health status. Assessments were performed at baseline, 2 weeks, and 3 months follow-up. Repeated measures ANOVAS were used to reveal possible therapy effects and effect sizes were calculated. After the intervention the experimental group had improved knowledge of pain neurophysiology (Pphysiology. Pain physiology education seems to be a useful component in the treatment of FM patients as it improves health status and endogenous pain inhibition in the long term.

  7. The acute effects of graded physiological strain on soccer kicking performance: a randomized, controlled cross-over study.

    Science.gov (United States)

    Radman, Ivan; Wessner, Barbara; Bachl, Norbert; Ruzic, Lana; Hackl, Markus; Prpic, Tomislav; Markovic, Goran

    2016-02-01

    The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance. Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones. Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p soccer kicking performance. The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.

  8. Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity.

    Science.gov (United States)

    Engward, Hilary; Davis, Geraldine

    2015-07-01

    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.

  9. Integrating Reflexivity in Livelihoods Research

    DEFF Research Database (Denmark)

    Prowse, Martin

    2010-01-01

    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 research...... 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....

  10. Reflex syncope: Diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Richard Sutton

    2017-12-01

    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

  11. Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society

    Science.gov (United States)

    Lange, K. A.

    1980-01-01

    Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases.

  12. Two ways to support reflexivity

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Knudsen, Hanne

    2013-01-01

    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...... Management (MEM). MEM provides the participating managers with a new language that can give them a critical distance to the overload of expectations they meet at work and MEM teaches the participants to translate this new language into practice. The pedagogy used for this is labelled ‘experimental management...

  13. Bernstein Lethargy Theorem and Reflexivity

    OpenAIRE

    Aksoy, Asuman Güven; Peng, Qidi

    2018-01-01

    In this paper, we prove the equivalence of reflexive Banach spaces and those Banach spaces which satisfy the following form of Bernstein's Lethargy Theorem. Let $X$ be an arbitrary infinite-dimensional Banach space, and let the real-valued sequence $\\{d_n\\}_{n\\ge1}$ decrease to $0$. Suppose that $\\{Y_n\\}_{n\\ge1}$ is a system of strictly nested subspaces of $X$ such that $\\overline Y_n \\subset Y_{n+1}$ for all $n\\ge1$ and for each $n\\ge1$, there exists $y_n\\in Y_{n+1}\\backslash Y_n$ such that ...

  14. Adaptation to sensory-motor reflex perturbations is blind to the source of errors.

    Science.gov (United States)

    Hudson, Todd E; Landy, Michael S

    2012-01-06

    In the study of visual-motor control, perhaps the most familiar findings involve adaptation to externally imposed movement errors. Theories of visual-motor adaptation based on optimal information processing suppose that the nervous system identifies the sources of errors to effect the most efficient adaptive response. We report two experiments using a novel perturbation based on stimulating a visually induced reflex in the reaching arm. Unlike adaptation to an external force, our method induces a perturbing reflex within the motor system itself, i.e., perturbing forces are self-generated. This novel method allows a test of the theory that error source information is used to generate an optimal adaptive response. If the self-generated source of the visually induced reflex perturbation is identified, the optimal response will be via reflex gain control. If the source is not identified, a compensatory force should be generated to counteract the reflex. Gain control is the optimal response to reflex perturbation, both because energy cost and movement errors are minimized. Energy is conserved because neither reflex-induced nor compensatory forces are generated. Precision is maximized because endpoint variance is proportional to force production. We find evidence against source-identified adaptation in both experiments, suggesting that sensory-motor information processing is not always optimal.

  15. A new method to determine reflex latency induced by high rate stimulation of the nervous system

    Directory of Open Access Journals (Sweden)

    Ilhan eKaracan

    2014-07-01

    Full Text Available High rate stimulations of the neuromuscular system, such as continuous whole body vibration, tonic vibration reflex and high frequency electrical stimulation, are used in the physiological research with an increasing interest. In these studies, the neuronal circuitries underlying the reflex responses remain unclear due to the problem of determining the exact reflex latencies. We present a novel cumulated average method to determine the reflex latency during high rate stimulation of the nervous system which was proven to be significantly more accurate than the classical method. The classical method, cumulant density analysis, reveals the relationship between the two synchronously recorded signals as a function of the lag between the signals. The comparison of new method with the classical technique and their relative accuracy was tested using a computer simulation. In the simulated signals the EMG response latency was constructed to be exactly 40 ms. The new method accurately indicated the value of the simulated reflex latency (40 ms. However, the classical method showed that the lag time between the simulated triggers and the simulated signals was 49 ms. Simulation results illustrated that the cumulated average method is a reliable and more accurate method compared with the classical method. We therefore suggest that the new cumulated average method is able to determine the high rate stimulation induced reflex latencies more accurately than the classical method.

  16. 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.

    Science.gov (United States)

    Stirbys, Petras

    2016-01-01

    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

  17. [New theory of holistic integrative physiology and medicine. II: New insight of the control and regulation of circulation].

    Science.gov (United States)

    Sun, Xing-guo

    2015-07-01

    The interpretation of control and regulation of circulatory parameters in traditional physiology has some limitations. Human being is an organic, circulatory control and regulation should involve all the systems. Based upon the theory of holistic integrative physiology and medicine, we approach to explain the circulatory control and regulation from its purpose. The main purpose of circulation is to maintain a stable metabolism of cells, i.e. transport oxygen (from lung) and nutrients (from gastrointestinal tract) to cells, and return carbon dioxide and metabolic products back for elimination. Based on this goal, all respiration and gastrointestinal digestion, absorption, urinary excretion, etc. are integrative together for regulation to maintain the supply-demand balance at any metabolic status of resting, exercise and sleep. So that, we can explain many existing problems and questions, for example: why and how the foramen ovale closed after birth; mechanism of Cheyne-Stokes respiration; blood flow redistribution during exercise; variabilities of systolic blood pressure, heart rate and autonomic tone. The circulatory control and regulation is the integration of all systems of the body.

  18. Nasal Physiology

    Science.gov (United States)

    ... Caregivers Contact ARS HOME ANATOMY Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy Skull Base Anatomy Virtual Anatomy Disclosure ... Patient Education About this Website Font Size + - Home > ANATOMY > Nasal Physiology Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy ...

  19. Researching Reflexively With Patients and Families: Two Studies Using Video-Reflexive Ethnography to Collaborate With Patients and Families in Patient Safety Research.

    Science.gov (United States)

    Collier, Aileen; Wyer, Mary

    2016-06-01

    Patient safety research has to date offered few opportunities for patients and families to be actively involved in the research process. This article describes our collaboration with patients and families in two separate studies, involving end-of-life care and infection control in acute care. We used the collaborative methodology of video-reflexive ethnography, which has been primarily used with clinicians, to involve patients and families as active participants and collaborators in our research. The purpose of this article is to share our experiences and findings that iterative researcher reflexivity in the field was critical to the progress and success of each study. We present and analyze the complexities of reflexivity-in-the-field through a framework of multilayered reflexivity. We share our lessons here for other researchers seeking to actively involve patients and families in patient safety research using collaborative visual methods. © The Author(s) 2015.

  20. Soleus muscle H-reflex monitoring in endoscopic surgery under general anesthesia percutaneous interlaminar approach.

    Science.gov (United States)

    Wang, Huixue; Gao, Yingji; Ji, Lixin; Bai, Wanshan

    2018-05-01

    The clinical value of soleus muscle H-reflex monitoring in general anesthesia percutaneous interlaminar approach was investigated. A total of 80 cases with unilateral L5-S1 disc herniation between January 2015 and October 2016 were randomly divided into control group (without soleus muscle H-reflex monitoring, n=40) and observation group (with soleus muscle H-reflex monitoring, n=40). Results showed that the operation time of the observation group was shorter than that of the control group (Ph after operation, the amplitude of H-reflex in diseased side soleus muscle was significantly lower than that in healthy side (Ph postoperatively, the latency of H-reflex in diseased side soleus muscle was shorter than that of healthy side (PH-reflex latency in soleus muscle were significantly lower (PH-reflex monitoring can effectively reduce the damage to the nerve roots under percutaneous endoscopic intervertebral endoscopic surgery under general anesthesia, improve the accuracy of surgery, reduce the complications, shorten the operation time and reduce the surgical bleeding, which is more beneficial to patients smooth recovery.

  1. Stochastic control of living systems: Normalization of physiological functions by magnetic field with 1/f power spectrum

    Science.gov (United States)

    Muzalevskaya, N. I.; Uritsky, V. M.; Korolyov, E. V.; Reschikov, A. M.; Timoshinov, G. P.

    1993-08-01

    For the first time correcting stochastic control of physiological status of living systems by weak low-frequency fluctuating magnetic field with 1/f spectrum (1/f MF) is demonstrated experimentally. The correction was observed in all main systems, including cardiovascular, central nervous, immunity systems of experimental animals. Pronounced prophylactic and therapeutic influence of 1/f MF on malignant growth and radiation disease was discovered. Theoretical interpretation of the results obtained is based upon the notion of fundamental role of 1/f fluctuations in homeostasis of living systems.

  2. Reflexive Aero Structures for Enhanced Survivability, Phase I

    Data.gov (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...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    of the body in order to maintain dynamic equilibrium during walking. Therefore, we hypothesized that if we suddenly slowed the treadmill participants were walking on, the cBF reflex would be inhibited because the necessity to break the forward progression of the body would be decreased. Conversely, if we...... 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....

  4. The Face of Physiology

    Directory of Open Access Journals (Sweden)

    Paul White

    2008-10-01

    Full Text Available This article explores the relationship between the physiology of the emotions and the display of character in Victorian Britain. Charles Bell and others had begun to link certain physiological functions, such as respiration, with the expression of feelings such as fear, regarding the heart and other internal organs as instruments by which the emotions were made visible. But a purely functional account of the emotions, which emerged through the development of reflex physiology during the second half of the century, would dramatically alter the nature of feelings and the means of observing them. At the same time, instinctual or acquired sympathy, which had long underpinned the accurate reading of expressions, became a problem to be surmounted by new 'objectively'. Graphic recording instruments measuring a variety of physiological functions and used with increasing frequency in clinical diagnostics became of fundamental importance for tracing the movement of feelings during the period prior to the development of cinematography. They remained, in the form of devices such as the polygraph, a crucial and controversial means of measuring affective states, beneath the potentially deceptive surface of the body.

  5. Reflexive criteria of sociological research

    Directory of Open Access Journals (Sweden)

    R T Ubaydullaeva

    2014-12-01

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

    Science.gov (United States)

    Onushko, Tanya; Hyngstrom, Allison

    2013-01-01

    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, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

  7. The interaction of psychological and physiological homeostatic drives and role of general control principles in the regulation of physiological systems, exercise and the fatigue process - The Integrative Governor theory.

    Science.gov (United States)

    St Clair Gibson, A; Swart, J; Tucker, R

    2018-02-01

    Either central (brain) or peripheral (body physiological system) control mechanisms, or a combination of these, have been championed in the last few decades in the field of Exercise Sciences as how physiological activity and fatigue processes are regulated. In this review, we suggest that the concept of 'central' or 'peripheral' mechanisms are both artificial constructs that have 'straight-jacketed' research in the field, and rather that competition between psychological and physiological homeostatic drives is central to the regulation of both, and that governing principles, rather than distinct physical processes, underpin all physical system and exercise regulation. As part of the Integrative Governor theory we develop in this review, we suggest that both psychological and physiological drives and requirements are underpinned by homeostatic principles, and that regulation of the relative activity of each is by dynamic negative feedback activity, as the fundamental general operational controller. Because of this competitive, dynamic interplay, we propose that the activity in all systems will oscillate, that these oscillations create information, and comparison of this oscillatory information with either prior information, current activity, or activity templates create efferent responses that change the activity in the different systems in a similarly dynamic manner. Changes in a particular system are always the result of perturbations occurring outside the system itself, the behavioural causative 'history' of this external activity will be evident in the pattern of the oscillations, and awareness of change occurs as a result of unexpected rather than planned change in physiological activity or psychological state.

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

    Directory of Open Access Journals (Sweden)

    Andreas Mühlbeier

    2017-06-01

    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. Isometric Exercise for the Cervical Extensors Can Help Restore Physiological Lordosis and Reduce Neck Pain: A Randomized Controlled Trial.

    Science.gov (United States)

    Alpayci, Mahmut; İlter, Server

    2017-09-01

    The aim of this study was to investigate whether isometric neck extension exercise restores physiological cervical lordosis and reduces pain. Sixty-five patients with loss of cervical lordosis were randomly assigned to exercise (27 women, 7 men; mean age, 32.82 ± 8.83 yrs) and control (26 women, 5 men; mean age, 33.48 ± 9.67 yrs) groups. Both groups received nonsteroidal anti-inflammatory drugs for 10 days. The exercise group received additional therapy as a home exercise program, which consisted of isometric neck extension for 3 mos. Neck pain severity and cervical lordosis were measured at baseline and at 3 mos after baseline. Compared with baseline levels, cervical lordosis angle was significantly improved in the exercise group (P cervical lordosis angle returned to physiological conditions (85.2% vs. 22.5%; P pain intensity was significantly reduced in both groups compared with baseline levels (for all, P pain was about twice in the exercise group compared with the control group (P cervical lordosis and pain.

  10. Impulses of physiology and psychology for the design of central control rooms

    International Nuclear Information System (INIS)

    Benz, C.

    1980-01-01

    Subsequent to a presentation of the man-machine-system in process control, the various operational steps are described. The problems of control are derived from the tasks to be accomplished by the operator. Measures are presented and discussed to overcome the stages of low demand and high demand on the operator's attention. (orig.) [de

  11. How Can Hypnodontics Manage Severe Gag Reflex for Root Canal Therapy? A Case Report

    Science.gov (United States)

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

    2016-01-01

    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

  12. An electromechanical swing-phase-controlled prosthetic knee joint for conversion of physiological energy to electrical energy: feasibility study.

    Science.gov (United States)

    Andrysek, Jan; Chau, Gilbert

    2007-12-01

    Microprocessor-controlled prostheses facilitate a more natural and efficient gait for individuals with above-knee amputations by continually adjusting the level of swing-phase damping. One caveat associated with these technologies is that the user must charge the onboard batteries on a daily basis. It is, therefore, the aim of this study to examine the feasibility of using an electromechanical system to provide prosthetic swing-phase damping and, concomitantly, the function of converting physiological energy that is normally dissipated during the swing phase, to electrical energy. Gait data from a single subject and data from a kinematic simulator were used to develop an empirical model. The findings in this study indicate that an electromagnetic system has appropriate characteristics for use in swing-phase control and also has the potential to recover energy under particular conditions.

  13. Importance of temperature control for HEFLEX, a biological experiment for Spacelab 1. [plant gravitational physiology study

    Science.gov (United States)

    Chapman, D. K.; Brown, A. H.

    1979-01-01

    The importance of temperature control to HEFLEX, a Spacelab experiment designed to measure kinetic properties of Helianthis nutation in a low-g environment, is discussed. It is argued that the development of the HEFLEX experiment has been severely hampered by the inadequate control of ambient air temperature provided by the spacecraft module design. A worst case calculation shows that delivery of only 69% of the maximum yield of useful data from the HEFLEX system is guaranteed; significant data losses from inadequate temperature control are expected. The magnitude of the expected data losses indicates that the cost reductions associated with imprecise temperature controls may prove to be a false economy in the long term.

  14. Effect of e-Cigarette Use on Cough Reflex Sensitivity.

    Science.gov (United States)

    Dicpinigaitis, Peter V; Lee Chang, Alfredo; Dicpinigaitis, Alis J; Negassa, Abdissa

    2016-01-01

    E-cigarettes (e-cigs) have attained widespread popularity, yet knowledge of their physiologic effects remains minimal. The aim of this study was to evaluate the effect of a single exposure to e-cig vapor on cough reflex sensitivity. Thirty healthy nonsmokers underwent cough reflex sensitivity measurement using capsaicin cough challenge at baseline, 15 min, and 24 h after e-cig exposure (30 puffs 30 s apart). The end point of cough challenge is the concentration of capsaicin inducing five or more coughs (C5). The number of coughs induced by each e-cig inhalation was counted. A subgroup of subjects (n = 8) subsequently underwent an identical protocol with a non-nicotine-containing e-cig. Cough reflex sensitivity was significantly inhibited (C5 increased) 15 min after e-cig use (?0.29; 95% CI, ?0.43 to ?0.15; P < .0001); 24 h later, C5 returned to baseline (0.24; 95% CI, 0.10-0.38; P = .0002 vs post-15-min value). A subgroup of eight subjects demonstrating the largest degree of cough reflex inhibition had no suppression after exposure to a non-nicotine-containing e-cig (P = .0078 for comparison of ?C5 after nicotine vs non-nicotine device). Furthermore, more coughing was induced by the nicotine-containing vs non-nicotine-containing device (P = .0156). A single session of e-cig use, approximating nicotine exposure of one tobacco cigarette, induces significant inhibition of cough reflex sensitivity. Exploratory analysis of a subgroup of subjects suggests that nicotine is responsible for this observation. Our data, consistent with previous studies of nicotine effect, suggest a dual action of nicotine: an immediate, peripheral protussive effect and a delayed central antitussive effect. ClinicalTrials.gov; No.: NCT02203162; URL: www.clinicaltrials.gov. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  15. The Multiple Faces of Reflexive Research Designs

    Directory of Open Access Journals (Sweden)

    Karl H. Müller

    2015-10-01

    Full Text Available Reflexive research can be grouped into five clusters with circular relations between two elements x ↔ x, namely circular relations between observers, between scientific building blocks like concepts, theories or models, between systemic levels, between rules and rule systems or as circular relations or x ↔ y between these four components. By far the most important cluster is the second cluster which becomes reflexive through a re-entry operation RE into a scientific element x and which establishes its circular formation as x(x. Many of the research problems in these five clusters in reflexivity research are still unexplored and pose grand challenges for future research.

  16. A near catastrophe from trigeminocardiac reflex

    Directory of Open Access Journals (Sweden)

    Parmod K Bithal

    2017-01-01

    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.

  17. Physiological complexity and system adaptability: evidence from postural control dynamics of older adults.

    Science.gov (United States)

    Manor, Brad; Costa, Madalena D; Hu, Kun; Newton, Elizabeth; Starobinets, Olga; Kang, Hyun Gu; Peng, C K; Novak, Vera; Lipsitz, Lewis A

    2010-12-01

    The degree of multiscale complexity in human behavioral regulation, such as that required for postural control, appears to decrease with advanced aging or disease. To help delineate causes and functional consequences of complexity loss, we examined the effects of visual and somatosensory impairment on the complexity of postural sway during quiet standing and its relationship to postural adaptation to cognitive dual tasking. Participants of the MOBILIZE Boston Study were classified into mutually exclusive groups: controls [intact vision and foot somatosensation, n = 299, 76 ± 5 (SD) yr old], visual impairment only (Postural sway (i.e., center-of-pressure) dynamics were assessed during quiet standing and cognitive dual tasking, and a complexity index was quantified using multiscale entropy analysis. Postural sway speed and area, which did not correlate with complexity, were also computed. During quiet standing, the complexity index (mean ± SD) was highest in controls (9.5 ± 1.2) and successively lower in the visual (9.1 ± 1.1), somatosensory (8.6 ± 1.6), and combined (7.8 ± 1.3) impairment groups (P = 0.001). Dual tasking resulted in increased sway speed and area but reduced complexity (P postural sway speed from quiet standing to dual-tasking conditions. Sensory impairments contributed to decreased postural sway complexity, which reflected reduced adaptive capacity of the postural control system. Relatively low baseline complexity may, therefore, indicate control systems that are more vulnerable to cognitive and other stressors.

  18. Musculoskeletal model-based control interface mimics physiologic hand dynamics during path tracing task

    Science.gov (United States)

    Crouch, Dustin L.; (Helen Huang, He

    2017-06-01

    Objective. We investigated the feasibility of a novel, customizable, simplified EMG-driven musculoskeletal model for estimating coordinated hand and wrist motions during a real-time path tracing task. Approach. A two-degree-of-freedom computational musculoskeletal model was implemented for real-time EMG-driven control of a stick figure hand displayed on a computer screen. After 5-10 minutes of undirected practice, subjects were given three attempts to trace 10 straight paths, one at a time, with the fingertip of the virtual hand. Able-bodied subjects completed the task on two separate test days. Main results. Across subjects and test days, there was a significant linear relationship between log-transformed measures of accuracy and speed (Pearson’s r  =  0.25, p  bodied subjects in 8 of 10 trials. For able-bodied subjects, tracing accuracy was lower at the extremes of the model’s range of motion, though there was no apparent relationship between tracing accuracy and fingertip location for the amputee. Our result suggests that, unlike able-bodied subjects, the amputee’s motor control patterns were not accustomed to the multi-joint dynamics of the wrist and hand, possibly as a result of post-amputation cortical plasticity, disuse, or sensory deficits. Significance. To our knowledge, our study is one of very few that have demonstrated the real-time simultaneous control of multi-joint movements, especially wrist and finger movements, using an EMG-driven musculoskeletal model, which differs from the many data-driven algorithms that dominate the literature on EMG-driven prosthesis control. Real-time control was achieved with very little training and simple, quick (~15 s) calibration. Thus, our model is potentially a practical and effective control platform for multifunctional myoelectric prostheses that could restore more life-like hand function for individuals with upper limb amputation.

  19. Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

    Science.gov (United States)

    Llewellyn, M; Yang, J F; Prochazka, A

    1990-01-01

    Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

  20. Effects of worry on physiological and subjective reactivity to emotional stimuli in generalized anxiety disorder and nonanxious control participants.

    Science.gov (United States)

    Llera, Sandra J; Newman, Michelle G

    2010-10-01

    The present study examined the effect of worry versus relaxation and neutral thought activity on both physiological and subjective responding to positive and negative emotional stimuli. Thirty-eight participants with generalized anxiety disorder (GAD) and 35 nonanxious control participants were randomly assigned to engage in worry, relaxation, or neutral inductions prior to sequential exposure to each of four emotion-inducing film clips. The clips were designed to elicit fear, sadness, happiness, and calm emotions. Self reported negative and positive affect was assessed following each induction and exposure, and vagal activity was measured throughout. Results indicate that worry (vs. relaxation) led to reduced vagal tone for the GAD group, as well as higher negative affect levels for both groups. Additionally, prior worry resulted in less physiological and subjective responding to the fearful film clip, and reduced negative affect in response to the sad clip. This suggests that worry may facilitate avoidance of processing negative emotions by way of preventing a negative emotional contrast. Implications for the role of worry in emotion avoidance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  1. Hypothalamic-Pituitary-Adrenal Axis Physiology and Cognitive Control of Behavior in Stress Inoculated Monkeys

    Science.gov (United States)

    Parker, Karen J.; Buckmaster, Christine L.; Lindley, Steven E.; Schatzberg, Alan F.; Lyons, David M.

    2012-01-01

    Monkeys exposed to stress inoculation protocols early in life subsequently exhibit diminished neurobiological responses to moderate psychological stressors and enhanced cognitive control of behavior during juvenile development compared to non-inoculated monkeys. The present experiments extended these findings and revealed that stress inoculated…

  2. Sympathetic β-adrenergic mechanism in pudendal inhibition of nociceptive and non-nociceptive reflex bladder activity.

    Science.gov (United States)

    Kadow, Brian T; Lyon, Timothy D; Zhang, Zhaocun; Lamm, Vladimir; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2016-07-01

    This study investigated the role of the hypogastric nerve and β-adrenergic mechanisms in the inhibition of nociceptive and non-nociceptive reflex bladder activity induced by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats, non-nociceptive reflex bladder activity was induced by slowly infusing saline into the bladder, whereas nociceptive reflex bladder activity was induced by replacing saline with 0.25% acetic acid (AA) to irritate the bladder. PNS was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. During saline infusion, PNS at 2T and 4T significantly (P reflex bladder activity. In addition to this peripheral mechanism, a central nervous system mechanism involving metabotropic glutamate 5 receptors also has a role in PNS inhibition. Copyright © 2016 the American Physiological Society.

  3. Portraying Reflexivity in Health Services Research.

    Science.gov (United States)

    Rae, John; Green, Bill

    2016-09-01

    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.

  4. The ubiquitous reflex and its critics in post-revolutionary Russia.

    Science.gov (United States)

    Sirotkina, Irina

    2009-03-01

    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.

  5. Closed-loop control of renal perfusion pressure in physiological experiments.

    Science.gov (United States)

    Campos-Delgado, D U; Bonilla, I; Rodríguez-Martínez, M; Sánchez-Briones, M E; Ruiz-Hernández, E

    2013-07-01

    This paper presents the design, experimental modeling, and control of a pump-driven renal perfusion pressure (RPP)-regulatory system to implement precise and relatively fast RPP regulation in rats. The mechatronic system is a simple, low-cost, and reliable device to automate the RPP regulation process based on flow-mediated occlusion. Hence, the regulated signal is the RPP measured in the left femoral artery of the rat, and the manipulated variable is the voltage applied to a dc motor that controls the occlusion of the aorta. The control system is implemented in a PC through the LabView software, and a data acquisition board NI USB-6210. A simple first-order linear system is proposed to approximate the dynamics in the experiment. The parameters of the model are chosen to minimize the error between the predicted and experimental output averaged from eight input/output datasets at different RPP operating conditions. A closed-loop servocontrol system based on a pole-placement PD controller plus dead-zone compensation was proposed for this purpose. First, the feedback structure was validated in simulation by considering parameter uncertainty, and constant and time-varying references. Several experimental tests were also conducted to validate in real time the closed-loop performance for stepwise and fast switching references, and the results show the effectiveness of the proposed automatic system to regulate the RPP in the rat, in a precise, accurate (mean error less than 2 mmHg) and relatively fast mode (10-15 s of response time).

  6. A biomimetic physiological model for human adipose tissue by adipocytes and endothelial cell cocultures with spatially controlled distribution

    International Nuclear Information System (INIS)

    Yao, Rui; Zhang, Renji; Lin, Feng; Du, Yanan; Luan, Jie

    2013-01-01

    An in vitro model that recapitulates the characteristics of native human adipose tissue would largely benefit pathology studies and therapy development. In this paper, we fabricated a physiological model composed of both human adipocytes and endothelial cells with spatially controlled distribution that biomimics the structure and composition of human adipose tissue. Detailed studies into the cell–cell interactions between the adipocytes and endothelial cells revealed a mutual-enhanced effect which resembles the in vivo routine. Furthermore, comparisons between planar coculture and model coculture demonstrated improved adipocyte function as well as endothelial cell proliferation under the same conditions. This research provided a reliable model for human adipose tissue development studies and potential obesity-related therapy development. (paper)

  7. The passive of reflexive verbs in Icelandic

    Directory of Open Access Journals (Sweden)

    Hlíf Árnadóttir

    2011-10-01

    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 (tímarit.is. 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.

  8. Effects of two different feeding positions on physiological characteristics and feeding performance of preterm infants: A randomized controlled trial.

    Science.gov (United States)

    Girgin, Burcu Aykanat; Gözen, Duygu; Karatekin, Güner

    2018-04-01

    The aim of this randomized controlled study was to determine the effect of semielevated side-lying (ESL) and semielevated supine (ESU) positions, which are used to bottle-feed preterm infants, on their physiological characteristics and feeding performance. The sample consisted of preterm infants who were born in the 31st gestational week and below, and met the inclusion criteria. A randomization was provided in the sample group with a total of 80 infants including 38 infants in the ESL (experimental) group and 42 infants in the ESU (control) group. Both groups were compared in terms of their SpO2 values, heart rates, and feeding performances before, during, and after the feeding. The data were obtained by using a form for infant descriptive characteristics, feeding follow-up form, a Masimo Radical-7 pulse oximeter device, and a video camera. It was determined that the infants in the ESL group had statistically significantly higher SpO2 values (ESL: 96.77 ± 2.51; ESU: 93.48 ± 5.63) and lower heart rates (ESL: 155.87 ± 11.18; ESU: 164.35 ± 6.00) during the feeding compared to the infants in the ESU group (p ESL group. The ESL position has a more positive effect on oxygen saturation and heart rate of infants and it is more effective in providing a physiological stabilization during the feeding, compared to the ESU position. According to these results, the ESL position can be recommended for preterm feeding. © 2018 Wiley Periodicals, Inc.

  9. Method and System for Physiologically Modulating Videogames and Simulations which Use Gesture and Body Image Sensing Control Input Devices

    Science.gov (United States)

    Pope, Alan T. (Inventor); Stephens, Chad L. (Inventor); Habowski, Tyler (Inventor)

    2017-01-01

    Method for physiologically modulating videogames and simulations includes utilizing input from a motion-sensing video game system and input from a physiological signal acquisition device. The inputs from the physiological signal sensors are utilized to change the response of a user's avatar to inputs from the motion-sensing sensors. The motion-sensing system comprises a 3D sensor system having full-body 3D motion capture of a user's body. This arrangement encourages health-enhancing physiological self-regulation skills or therapeutic amplification of healthful physiological characteristics. The system provides increased motivation for users to utilize biofeedback as may be desired for treatment of various conditions.

  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.

    1990-01-01

    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. The link between antioxidant enzymes catalase and glutathione S-transferase and physiological condition of a control population of terrestrial isopod (Porcellio scaber).

    Science.gov (United States)

    Jemec, Anita; Lešer, Vladka; Drobne, Damjana

    2012-05-01

    The aim of this work was to investigate if the activities of catalase and glutathione S-transferase in a control population of terrestrial isopods (Porcellio scaber) are correlated with the physiological condition of the isopods. For this purpose, the activities of these enzymes were analysed in isopods from a stock population and in parallel, the physiological condition of the same specimens was assessed using a histological approach based on epithelial thickness and lipid droplets. We found a correlation between antioxidant enzymes and the physiological condition of the isopods. This implies that these enzymes could be used as predictive indicators of the physiological condition in a stock population before comprehensive toxicological studies are conducted and also in control group after the experiment. When a control group is found to be very heterogeneous in terms of physiological condition, the experiment should be repeated with a larger number of experimental animals. The findings of this study will contribute to more accurate experimental design of toxicity tests when using biomarkers. This should encourage other researchers to increase their effort to know the physiological state of their test organisms. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Rice Physiology

    Science.gov (United States)

    P.A. Counce; Davidi R. Gealy; Shi-Jean Susana Sung

    2002-01-01

    Physiology occurs tn physical space through chemical reactions constrained by anatomy and morphology, yet guided by genetics. Physiology has been called the logic of life. Genes encode structural and fimcdonal proteins. These proteins are subsequently processed to produce enzymes that direct and govern the biomechanical processes involved in the physiology of the...

  13. 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

  14. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment.

    Science.gov (United States)

    Wang, Yang; Zekveld, Adriana A; Naylor, Graham; Ohlenforst, Barbara; Jansma, Elise P; Lorens, Artur; Lunner, Thomas; Kramer, Sophia E

    2016-01-01

    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

  15. A interveniência do controlador societário em contratos de concessão do serviço público de distribuição de energia elétrica: disposições e inovações contratuais à luz do direito reflexivo / The Intervention of the Controlling Shareholder in Concession Contracts in the Public Service of Electricity Distribution: Provisions and Contractual Innovations in the Light of Reflexive Law

    Directory of Open Access Journals (Sweden)

    Acácio Alessandro Rêgo do Nascimento

    2015-10-01

    Full Text Available Purpose – It analyzes to what extent the intervention of the controlling shareholder and its inherent provisions in power distribution utilities contracts are validated in the light of reflexive law constructs. Methodology/approach/design – The dogmatic and socio-legal approach is applied, based on the theory of autopoiesis and reflexive law. It proceeds with the normative selection, tabulation and comparison of the contractual clauses related to the controlling shareholder, constant in the contracts of the ten most prominent power distribution utilities with the largest number of consumers and power distribution in 2013. It performs the critical examination of reflexivity of selected rules. Findings – It concludes that the intervention of the controlling shareholder at the investigated contracts is strongly embodied as reflexive strategies, notwithstanding contractual clauses have few reinforcement mechanisms for regulatory effectiveness. Practical implications – The application of theoretical principles disclosed in the article and the suggestions offered can be applied in new power distribution utilities contracts, with the purpose of increasing the regulatory effectiveness of the clauses.

  16. Effect of betel nut chewing on the otolithic reflex system.

    Science.gov (United States)

    Lin, Chuan-Yi; Young, Yi-Ho

    2017-01-01

    This study investigated the effect of betel nut chewing on the otolithic reflex system. Seventeen healthy volunteers without any experience of chewing betel nut (fresh chewers) and 17 habitual chewers underwent vital sign measurements, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests prior to the study. Each subject then chewed two pieces of betel nut for 2min (dosing). The same paradigm was repeated immediately, 10min, and 20min after chewing. On a different day, 10 fresh chewers masticated chewing gum as control. Fresh chewers exhibited significantly decreased response rates of oVEMP (53%) and cVEMP (71%) after dosing compared with those from the predosing period. These abnormal VEMPs returned to normal 20min after dosing. In contrast, 100% response rates of oVEMP and cVEMP were observed before and after masticating chewing gum. In habitual chewers, the response rates of oVEMP and cVEMP were 32% and 29%, respectively, 20min after dosing. Chewing betel nuts induced a transient loss of the otolithic reflexes in fresh chewers but may cause permanent loss in habitual chewers. Chewing betel nuts can cause a loss of otholitic reflex function. This creates a risk for disturbed balance and malfunction, for instance, during driving. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. ESO Reflex: A Graphical Workflow Engine for Data Reduction

    Science.gov (United States)

    Hook, R.; Romaniello, M.; Péron, M.; Ballester, P.; Gabasch, A.; Izzo, C.; Ullgrén, M.; Maisala, S.; Oittinen, T.; Solin, O.; Savolainen, V.; Järveläinen, P.; Tyynelä, J.

    2008-08-01

    Sampo {http://www.eso.org/sampo} (Hook et al. 2005) is a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal is to assess the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Those prototypes will not only be used to validate concepts and understand requirements but will also be tools of immediate value for the community. Most of the raw data produced by ESO instruments can be reduced using CPL {http://www.eso.org/cpl} recipes: compiled C programs following an ESO standard and utilizing routines provided by the Common Pipeline Library. Currently reduction recipes are run in batch mode as part of the data flow system to generate the input to the ESO VLT/VLTI quality control process and are also made public for external users. Sampo has developed a prototype application called ESO Reflex {http://www.eso.org/sampo/reflex/} that integrates a graphical user interface and existing data reduction algorithms. ESO Reflex can invoke CPL-based recipes in a flexible way through a dedicated interface. ESO Reflex is based on the graphical workflow engine Taverna {http://taverna.sourceforge.net} that was originally developed by the UK eScience community, mostly for work in the life sciences. Workflows have been created so far for three VLT/VLTI instrument modes ( VIMOS/IFU {http://www.eso.org/instruments/vimos/}, FORS spectroscopy {http://www.eso.org/instruments/fors/} and AMBER {http://www.eso.org/instruments/amber/}), and the easy-to-use GUI allows the user to make changes to these or create workflows of their own. Python scripts and IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available.

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

    National Research Council Canada - National Science Library

    Mrachacz-Kersting, N

    2001-01-01

    .... 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. "On Becoming a Critically Reflexive Practitioner" Redux: What Does It Mean to "Be" Reflexive?

    Science.gov (United States)

    Cunliffe, Ann L.

    2016-01-01

    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…

  20. Plantar reflex excitability is increased in the evening in restless legs syndrome patients.

    Science.gov (United States)

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

    2017-11-01

    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.

  1. Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help.

    Science.gov (United States)

    Thompson, Aiko K; Wolpaw, Jonathan R

    2015-04-01

    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.

  2. Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

    Science.gov (United States)

    Sasaki, Au; Hasegawa, Naoya; Adachi, Kazunori; Sakagami, Hiroshi; Suda, Naoto

    2017-10-01

    motor excitability has not been fully understood. We found that, during orthodontic treatment, trigeminal motor excitability is acutely increased and then decreased in a week. Because alteration of trigeminal motor function can be evaluated quantitatively by jaw-opening reflex excitability, the present animal model may be useful to search for alternative approaches to attenuate orthodontic pain. Copyright © 2017 the American Physiological Society.

  3. Advances in physiological computing

    CERN Document Server

    Fairclough, Stephen H

    2014-01-01

    This edited collection will provide an overview of the field of physiological computing, i.e. the use of physiological signals as input for computer control. It will cover a breadth of current research, from brain-computer interfaces to telemedicine.

  4. Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude.

    Science.gov (United States)

    Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

    2010-07-26

    To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by approximately 35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the

  5. Tonically Active α5GABAA Receptors Reduce Motoneuron Excitability and Decrease the Monosynaptic Reflex

    Directory of Open Access Journals (Sweden)

    Martha Canto-Bustos

    2017-09-01

    Full Text Available Motoneurons, the final common path of the Central Nervous System (CNS, are under a complex control of its excitability in order to precisely translate the interneuronal pattern of activity into skeletal muscle contraction and relaxation. To fulfill this relevant function, motoneurons are provided with a vast repertoire of receptors and channels, including the extrasynaptic GABAA receptors which have been poorly investigated. Here, we confirmed that extrasynaptic α5 subunit-containing GABAA receptors localize with choline acetyltransferase (ChAT positive cells, suggesting that these receptors are expressed in turtle motoneurons as previously reported in rodents. In these cells, α5GABAA receptors are activated by ambient GABA, producing a tonic shunt that reduces motoneurons’ membrane resistance and affects their action potential firing properties. In addition, α5GABAA receptors shunted the synaptic excitatory inputs depressing the monosynaptic reflex (MSR induced by activation of primary afferents. Therefore, our results suggest that α5GABAA receptors may play a relevant physiological role in motor control.

  6. Determinantes fisiológicos do controle do peso e apetite Physiological determinants of weight and appetite control

    Directory of Open Access Journals (Sweden)

    Zuleika S. C. Halpern

    2004-01-01

    Full Text Available A obesidade é um dos principais problemas de saúde pública da atualidade, apresentando etiologia multifatorial. Entre os determinantes fisiológicos do controle do peso e do apetite, estão fatores neuronais, endócrinos, adipocitários e intestinais. A leptina e a insulina são hormônios secretados em proporção à massa adiposa e atuam perifericamente, estimulando o catabolismo. No sistema nervoso central, a insulina e a leptina interagem com receptores hipotalâmicos, favorecendo a saciedade. Indivíduos obesos têm maiores concentrações séricas destes hormônios e apresentam resistência à sua ação. Os peptídeos intestinais, combinados a outros sinais, podem estimular (grelina e orexina ou inibir (CCK, leptina e oximodulina a ingestão alimentar. Todos atuam nos centros hipotalâmicos, que são os grandes responsáveis pelo comportamento alimentar.Obesity is currently one of the main problems of public health, presenting multifactorial etiology. The main involved factors in the control of weight and appetite are neuronal, endocrine, adipocity and intestinal. Leptine and insuline are hormones produced proportionally to adipose mass and act stimulating the catabolism. In the central nervous system, insuline and leptine interact with hypothalamic receivers favoring the satiety. Individuals with obesity have high seric concentrations of these hormones and present resistance to their action. The intestinal peptides, associated with other signals, can stimulate (greline and orexine or inhibit (CKK, leptine and oxymodulin the food intake. All act in the hypothalamic centers, that are the major responsible for the nutrititional behavior.

  7. Using ESO Reflex with Web Services

    Science.gov (United States)

    Järveläinen, P.; Savolainen, V.; Oittinen, T.; Maisala, S.; Ullgrén, M. Hook, R.

    2008-08-01

    ESO Reflex is a prototype graphical workflow system, based on Taverna, and primarily intended to be a flexible way of running ESO data reduction recipes along with other legacy applications and user-written tools. ESO Reflex can also readily use the Taverna Web Services features that are based on the Apache Axis SOAP implementation. Taverna is a general purpose Web Service client, and requires no programming to use such services. However, Taverna also has some restrictions: for example, no numerical types such integers. In addition the preferred binding style is document/literal wrapped, but most astronomical services publish the Axis default WSDL using RPC/encoded style. Despite these minor limitations we have created simple but very promising test VO workflow using the Sesame name resolver service at CDS Strasbourg, the Hubble SIAP server at the Multi-Mission Archive at Space Telescope (MAST) and the WESIX image cataloging and catalogue cross-referencing service at the University of Pittsburgh. ESO Reflex can also pass files and URIs via the PLASTIC protocol to visualisation tools and has its own viewer for VOTables. We picked these three Web Services to try to set up a realistic and useful ESO Reflex workflow. They also demonstrate ESO Reflex abilities to use many kind of Web Services because each of them requires a different interface. We describe each of these services in turn and comment on how it was used

  8. Swedish Massage and Abnormal Reflexes of Children with Spastic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Vida Alizad

    2007-09-01

    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.

  9. The effects of team reflexivity on psychological well-being in manufacturing teams.

    Science.gov (United States)

    Chen, Jingqiu; Bamberger, Peter A; Song, Yifan; Vashdi, Dana R

    2018-04-01

    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).

  10. Muscle and reflex changes with varying joint angle in hemiparetic stroke

    Directory of Open Access Journals (Sweden)

    Alibiglou Laila

    2008-02-01

    Full Text Available Abstract Background Despite intensive investigation, the origins of the neuromuscular abnormalities associated with spasticity are not well understood. In particular, the mechanical properties induced by stretch reflex activity have been especially difficult to study because of a lack of accurate tools separating reflex torque from torque generated by musculo-tendinous structures. The present study addresses this deficit by characterizing the contribution of neural and muscular components to the abnormally high stiffness of the spastic joint. Methods Using system identification techniques, we characterized the neuromuscular abnormalities associated with spasticity of ankle muscles in chronic hemiparetic stroke survivors. In particular, we systematically tracked changes in muscle mechanical properties and in stretch reflex activity during changes in ankle joint angle. Modulation of mechanical properties was assessed by applying perturbations at different initial angles, over the entire range of motion (ROM. Experiments were performed on both paretic and non-paretic sides of stroke survivors, and in healthy controls. Results Both reflex and intrinsic muscle stiffnesses were significantly greater in the spastic/paretic ankle than on the non-paretic side, and these changes were strongly position dependent. The major reflex contributions were observed over the central portion of the angular range, while the intrinsic contributions were most pronounced with the ankle in the dorsiflexed position. Conclusion In spastic ankle muscles, the abnormalities in intrinsic and reflex components of joint torque varied systematically with changing position over the full angular range of motion, indicating that clinical perceptions of increased tone may have quite different origins depending upon the angle where the tests are initiated. Furthermore, reflex stiffness was considerably larger in the non-paretic limb of stroke patients than in healthy control subjects

  11. Somatic modulation of spinal reflex bladder activity mediated by nociceptive bladder afferent nerve fibers in cats.

    Science.gov (United States)

    Xiao, Zhiying; Rogers, Marc J; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2014-09-15

    The goal of the present study was to determine if supraspinal pathways are necessary for inhibition of bladder reflex activity induced by activation of somatic afferents in the pudendal or tibial nerve. Cats anesthetized with α-chloralose were studied after acute spinal cord transection at the thoracic T9/T10 level. Dilute (0.25%) acetic acid was used to irritate the bladder, activate nociceptive afferent C-fibers, and trigger spinal reflex bladder contractions (amplitude: 19.3 ± 2.9 cmH2O). Hexamethonium (a ganglionic blocker, intravenously) significantly (P reflex bladder contractions to 8.5 ± 1.9 cmH2O. Injection of lidocaine (2%, 1-2 ml) into the sacral spinal cord or transection of the sacral spinal roots and spinal cord further reduced the contraction amplitude to 4.2 ± 1.3 cmH2O. Pudendal nerve stimulation (PNS) at frequencies of 0.5-5 Hz and 40 Hz but not at 10-20 Hz inhibited reflex bladder contractions, whereas tibial nerve stimulation (TNS) failed to inhibit bladder contractions at all tested frequencies (0.5-40 Hz). These results indicate that PNS inhibition of nociceptive afferent C-fiber-mediated spinal reflex bladder contractions can occur at the spinal level in the absence of supraspinal pathways, but TNS inhibition requires supraspinal pathways. In addition, this study shows, for the first time, that after acute spinal cord transection reflex bladder contractions can be triggered by activating nociceptive bladder afferent C-fibers using acetic acid irritation. Understanding the sites of action for PNS or TNS inhibition is important for the clinical application of pudendal or tibial neuromodulation to treat bladder dysfunctions. Copyright © 2014 the American Physiological Society.

  12. Reflexive Planning as Design and Work

    DEFF Research Database (Denmark)

    Lissandrello, Enza; Grin, John

    2011-01-01

    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......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...

  13. Cerebellar interaction with the acoustic reflex.

    Science.gov (United States)

    Jastreboff, P J

    1981-01-01

    The involvement of the cerebellar vermis in the acoustic reflex was analyzed in 12 cats, decerebrated or in pentobarbital anesthesia. Anatomical data suggested the existence of a connection of lobules VIII with the ventral cochlear nucleus. Single cell recording and evoked potential techniques demonstrated the existence of the acoustic projection to lobulus VIII. Electrical stimulation of this area changed the tension of the middle ear muscle and caused evoked potential responses in the caudal part of the ventral cochlear nucleus. Electrical stimulation of the motor nucleus of the facial nerve evoked a slow wave in the recording taken from the surrounding of the cochlear round window. A hypothesis is proposed which postulates the involvement of the acoustic reflex in space localization of acoustic stimuli and the action of cerebellar vermis in order to assure the stability and plasticity of the acoustic reflex arc.

  14. Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex

    Science.gov (United States)

    Dale, Karl Yngvar; Flaten, Magne Arve; Elden, Åke; Holte, Arne

    2008-01-01

    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

  15. Orthodoxy and reflexivity in international comparative analysis

    DEFF Research Database (Denmark)

    Lind, Jens; Valkenburg, Ben

    2002-01-01

    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...

  16. Probabilities on Streams and Reflexive Games

    Directory of Open Access Journals (Sweden)

    Andrew Schumann

    2014-01-01

    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

  17. Abnormal reflex activation of hamstring muscles in dogs with cranial cruciate ligament rupture.

    Science.gov (United States)

    Hayes, Graham M; Granger, Nicolas; Langley-Hobbs, Sorrel J; Jeffery, Nick D

    2013-06-01

    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.

  18. Charitable giving and reflexive individuals: How personal reflexivity mediates between structure and agency.

    Science.gov (United States)

    Sanghera, Balihar

    2017-03-01

    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.

  19. Enhancement of the intrinsic defecation reflex by mosapride, a 5-HT4 agonist, in chronically lumbosacral denervated guinea pigs.

    Science.gov (United States)

    Kojima, Yu; Fujii, Hisao; Katsui, Renta; Nakajima, Yoshiyuki; Takaki, Miyako

    2006-10-01

    The defecation reflex is composed of rectal distension-evoked rectal (R-R) reflex contractions and synchronous internal anal sphincter (R-IAS) reflex relaxations in guinea pigs. These R-R and R-IAS reflexes are controlled via extrinsic sacral excitatory nerve pathway (pelvic nerves), lumbar inhibitory nerve pathways (colonic nerves) and by intrinsic cholinergic excitatory and nitrergic inhibitory nerve pathways. The effect of mosapride (a prokinetic benzamide) on the intrinsic reflexes, mediated via enteric 5-HT(4) receptors, was evaluated by measuring the mechanical activity of the rectum and IAS in anesthetized guinea pigs using an intrinsic R-R and R-IAS reflex model resulting from chronic (two to nine days) lumbosacral denervation (PITH). In this model, the myenteric plexus remains undamaged and the distribution of myenteric and intramuscular interstitial cells of Cajal is unchanged. Although R-R and R-IAS reflex patterns markedly changed, the reflex indices (reflex pressure or force curve-time integral) of both the R-R contractions and the synchronous R-IAS relaxations were unchanged. The frequency of the spontaneous R and IAS motility was also unchanged. Mosapride (0.1-1.0 mg/kg) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indices (maximum: 2.76) from that of the control (1.0) 6-9 days following chronic PITH. The dose-response curve was similar to that in the intact guinea pig, and had shifted to the left from that in the guinea pig after acute PITH. A specific 5-HT(4) receptor antagonist, GR 113808 (1.0 mg/kg), decreased both reflex indices by approximately 50% and antagonized the effect of mosapride 1.0 mg/kg. This was quite different from the result in the intact guinea pig where GR 113808 (1.0 mg/kg) did not affect either of the reflex indices. The present results indicate that mosapride enhanced the intrinsic R-R and R-IAS reflexes and functionally compensated for the deprivation of extrinsic innervation. The actions of

  20. A pilot randomized control trial investigating the effect of mindfulness practice on pain tolerance, psychological well-being, and physiological activity

    DEFF Research Database (Denmark)

    Kingston, Jessica; Chadwick, Paul; Meron, Daniel

    2007-01-01

    Objective: To investigate the effect of mindfulness training on pain tolerance, psychological well-being, physiological activity, and the acquisition of mindfulness skills. Methods: Forty-two asymptomatic University students participated in a randomized, single-blind, active control pilot study. ...

  1. A simple measurement hammer for quantitative reflex studies

    NARCIS (Netherlands)

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

    1984-01-01

    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

  2. A Prototype Analysis of Spanish Indeterminate Reflexive Constructions.

    Science.gov (United States)

    Turley, Jeffrey S.

    1998-01-01

    Discussion of the Spanish indeterminate reflexive construction, the impersonal reflexive, finds that prototype theory allows this subjectless Spanish construction to be included within the category of generally subject-bearing indeterminates in Romance languages. (MSE)

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

    National Research Council Canada - National Science Library

    Tung, J

    2001-01-01

    ...) 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...

  4. Median sep and blink reflex in thyroid diseases.

    Science.gov (United States)

    Oflazoğlu, B; Somay, G; Us, O; Surardamar, A; Tanridağ, T

    2006-11-01

    Pathological disturbances of thyroid hormones is associated with central and peripheral nervous system disturbances. The aim of this study is to evaluate median nerve stimulated somatosensory evoked potential (SEP) and blink reflex of thyroid patients (hypo and hyperthyroidism). Median SEP was performed in 40 patients (21 with hyperthyroidism and 19 with hypothyroidism). We evaluated the latencies of N9, N11, N13, P9, P11, P14, N20 and P25 waves and the N9-N20, N9-N13, N13-N20 and P14-N20 interpeak latencies. We compared the results of patients with the control group (26 persons). We found that the N20 latency was longer in patients with hyperthyroidism than in the control group and the difference was statistically significant. There was not any statistically significant difference regarding the N9, N11, N13, P9, P11, P14, N20 and P25 latencies and the N9-N20, N9-N13, N13-N20 and P14-N20 interpeak latencies between hypothyroid patients and controls. We performed the blink reflex study in 28 of 40 patients (14 patients with hyperthyroidism and 14 patients with hypothyroidism). Comparing the R1, R2, CR2 (contralateral R2) latencies and durations of the patients and controls, we found that R2 and CR2 duration was shorter in patients with hyperthyroidism. This difference was statistically significant.

  5. Sleep duration, depression, and oxytocinergic genotype influence prepulse inhibition of the startle reflex in postpartum women.

    Science.gov (United States)

    Comasco, Erika; Gulinello, Maria; Hellgren, Charlotte; Skalkidou, Alkistis; Sylven, Sara; Sundström-Poromaa, Inger

    2016-04-01

    The postpartum period is characterized by a post-withdrawal hormonal status, sleep deprivation, and susceptibility to affective disorders. Postpartum mothering involves automatic and attentional processes to screen out new external as well as internal stimuli. The present study investigated sensorimotor gating in relation to sleep duration, depression, as well as catecholaminergic and oxytocinergic genotypes in postpartum women. Prepulse inhibition (PPI) of the startle reflex and startle reactivity were assessed two months postpartum in 141 healthy and 29 depressed women. The catechol-O-methyltransferase (COMT) Val158Met, and oxytocin receptor (OXTR) rs237885 and rs53576 polymorphisms were genotyped, and data on sleep duration were collected. Short sleep duration (less than four hours in the preceding night) and postpartum depression were independently associated with lower PPI. Also, women with postpartum depression had higher startle reactivity in comparison with controls. The OXTR rs237885 genotype was related to PPI in an allele dose-dependent mode, with T/T healthy postpartum women carriers displaying the lowest PPI. Reduced sensorimotor gating was associated with sleep deprivation and depressive symptoms during the postpartum period. Individual neurophysiological vulnerability might be mediated by oxytocinergic genotype which relates to bonding and stress response. These findings implicate the putative relevance of lower PPI of the startle response as an objective physiological correlate of liability to postpartum depression. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

  6. Inhibition of micturition reflex by activation of somatic afferents in posterior femoral cutaneous nerve.

    Science.gov (United States)

    Tai, Changfeng; Shen, Bing; Mally, Abhijith D; Zhang, Fan; Zhao, Shouguo; Wang, Jicheng; Roppolo, James R; de Groat, William C

    2012-10-01

    This study determined if activation of somatic afferents in posterior femoral cutaneous nerve (PFCN) could modulate the micturition reflex recorded under isovolumetric conditions in α-chloralose anaesthetized cats. PFCN stimulation inhibited reflex bladder activity and significantly (P acid (AA). The optimal frequency for PFCN stimulation-induced bladder inhibition was between 3 and 10 Hz, and a minimal stimulation intensity of half of the threshold for inducing anal twitching was required. Bilateral pudendal nerve transection eliminated PFCN stimulation-induced anal twitching but did not change the stimulation-induced bladder inhibition, excluding the involvement of pudendal afferent or efferent axons in PFCN afferent inhibition.Mechanical or electrical stimulation on the skin surface in the PFCN dermatome also inhibited bladder activity. Prolonged (2 × 30 min) PFCN stimulation induced a post-stimulation inhibition that persists for at least 2 h. This study revealed a new cutaneous-bladder reflex activated by PFCN afferents. Although the mechanisms and physiological functions of this cutaneous-bladder reflex need to be further studied, our data raise the possibility that stimulation of PFCN afferents might be useful clinically for the treatment of overactive bladder symptoms.

  7. Comparison of cough reflex testing with videoendoscopy in recently extubated intensive care unit patients.

    Science.gov (United States)

    Kallesen, Molly; Psirides, Alex; Huckabee, Maggie-Lee

    2016-06-01

    Orotracheal intubation is known to impair cough reflex, but the validity of cough reflex testing (CRT) as a screening tool for silent aspiration in this population is unknown. One hundred and six participants in a tertiary-level intensive care unit (ICU) underwent CRT and videoendoscopic evaluation of swallowing (VES) within 24 hours of extubation. Cough reflex threshold was established for each participant using nebulized citric acid. Thirty-nine (37%) participants had an absent cough to CRT. Thirteen (12%) participants aspirated on VES, 9 (69%) without a cough response. Sensitivity of CRT to identify silent aspiration was excellent, but specificity was poor. There was a significant correlation between intubation duration and presence of aspiration on VES (P= .0107). There was no significant correlation between silent aspiration on VES and length of intubation, age, sex, diagnosis at intensive care unit admission, indication for intubation, Acute Physiology and Chronic Health Evaluation III score, morphine equivalent dose, or time of testing postextubation. Intensive care unit patients are at increased risk of aspiration in the 24 hours following extubation, and an impaired cough reflex is common. However, CRT overidentifies risk of silent aspiration in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Biological Motion Cues Trigger Reflexive Attentional Orienting

    Science.gov (United States)

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

    2010-01-01

    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…

  9. Dilemmas and Deliberations in Reflexive Ethnographic Research

    Science.gov (United States)

    Robinson, Janean Valerie

    2014-01-01

    This paper traces insights into the challenges and dilemmas experienced whilst researching students' interpretations and understandings of the Behaviour Management in Schools policy in Western Australia. Journal records, supported by student transcripts, are woven together in a reflexive ethnographic journey--from the beginning phase of searching…

  10. Reflex epilepsy: triggers and management strategies

    Directory of Open Access Journals (Sweden)

    Okudan ZV

    2018-01-01

    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

  11. The acoustic reflex threshold in aging ears.

    Science.gov (United States)

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

    1983-01-01

    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.

  12. A reflexive perspective in problem solving

    OpenAIRE

    Chio, José Angel; Álvarez, Aida; López, Margarita

    2013-01-01

    The objective of this paper is to favour the methodological process of reflexive analysis in problem solving in the general teaching methods that concentrates in strengthening the dimensional analysis, to gain a greater preparation of the students for the solution of mathematical problems.

  13. A Study on the Effects of Bee Venom Aqua-Acupuncture on Writhing Reflex

    Directory of Open Access Journals (Sweden)

    Jeong Sun-Hee

    2000-07-01

    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

  14. Snout and Visual Rooting Reflexes in Infantile Autism. Brief Report.

    Science.gov (United States)

    Minderaa, Ruud B.; And Others

    1985-01-01

    The authors conducted extensive neurological evaluations of 42 autistic individuals and were surprised to discover a consistently positive snout reflex in most of them. Difficulties with assessing the reflex are noted. The authors then reassessed the Ss for a series of primitive reflexes which are interpreted as signs of diffuse cortical brain…

  15. Effect of chronic and acute cigarette smoking on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow

    OpenAIRE

    Dua, K; Bardan, E; Ren, J; Sui, Z; Shaker, R

    1998-01-01

    Background—Cigarette smoking is known to affect adversely the defence mechanisms against gastro-oesophageal reflux. The effect of smoking on the supraoesophageal reflexes that prevent aspiration of gastric contents has not been previously studied. 
Aims—To elucidate the effect of cigarette smoking on two of the supraoesophageal reflexes: the pharyngo-upper oesophageal sphincter (UOS) contractile reflex; and the reflexive pharyngeal swallow. 
Methods—Ten chronic smokers and 10 non-...

  16. Locomotor training improves premotoneuronal control after chronic spinal cord injury.

    Science.gov (United States)

    Knikou, Maria; Mummidisetty, Chaithanya K

    2014-06-01

    Spinal inhibition is significantly reduced after spinal cord injury (SCI) in humans. In this work, we examined if locomotor training can improve spinal inhibition exerted at a presynaptic level. Sixteen people with chronic SCI received an average of 45 training sessions, 5 days/wk, 1 h/day. The soleus H-reflex depression in response to low-frequency stimulation, presynaptic inhibition of soleus Ia afferent terminals following stimulation of the common peroneal nerve, and bilateral EMG recovery patterns were assessed before and after locomotor training. The soleus H reflexes evoked at 1.0, 0.33, 0.20, 0.14, and 0.11 Hz were normalized to the H reflex evoked at 0.09 Hz. Conditioned H reflexes were normalized to the associated unconditioned H reflex evoked with subjects seated, while during stepping both H reflexes were normalized to the maximal M wave evoked after the test H reflex at each bin of the step cycle. Locomotor training potentiated homosynaptic depression in all participants regardless the type of the SCI. Presynaptic facilitation of soleus Ia afferents remained unaltered in motor complete SCI patients. In motor incomplete SCIs, locomotor training either reduced presynaptic facilitation or replaced presynaptic facilitation with presynaptic inhibition at rest. During stepping, presynaptic inhibition was modulated in a phase-dependent manner. Locomotor training changed the amplitude of locomotor EMG excitability, promoted intralimb and interlimb coordination, and altered cocontraction between knee and ankle antagonistic muscles differently in the more impaired leg compared with the less impaired leg. The results provide strong evidence that locomotor training improves premotoneuronal control after SCI in humans at rest and during walking. Copyright © 2014 the American Physiological Society.

  17. Physiological parameters

    International Nuclear Information System (INIS)

    Natera, E.S.

    1998-01-01

    The physiological characteristics of man depend on the intake, metabolism and excretion of stable elements from food, water, and air. The physiological behavior of natural radionuclides and radionuclides from nuclear weapons testing and from the utilization of nuclear energy is believed to follow the pattern of stable elements. Hence information on the normal physiological processes occurring in the human body plays an important role in the assessment of the radiation dose received by man. Two important physiological parameters needed for internal dose determination are the pulmonary function and the water balance. In the Coordinated Research Programme on the characterization of Asian population, five participants submitted data on these physiological characteristics - China, India, Japan, Philippines and Viet Nam. During the CRP, data on other pertinent characteristics such as physical and dietary were simultaneously being collected. Hence, the information on the physiological characteristics alone, coming from the five participants were not complete and are probably not sufficient to establish standard values for the Reference Asian Man. Nonetheless, the data collected is a valuable contribution to this research programme

  18. Modulation of the Fibularis Longus Hoffmann Reflex and Postural Instability Associated With Chronic Ankle Instability

    Science.gov (United States)

    Kim, Kyung-Min; Hart, Joseph M.; Saliba, Susan A.; Hertel, Jay

    2016-01-01

    Context: Individuals with chronic ankle instability (CAI) present with decreased modulation of the Hoffmann reflex (H-reflex) from a simple to a more challenging task. The neural alteration is associated with impaired postural control, but the relationship has not been investigated in individuals with CAI. Objective: To determine differences in H-reflex modulation and postural control between individuals with or without CAI and to identify if they are correlated in individuals with CAI. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: A total of 15 volunteers with CAI (9 males, 6 females; age = 22.6 ± 5.8 years, height = 174.7 ± 8.1 cm, mass = 74.9 ± 12.8 kg) and 15 healthy sex-matched volunteers serving as controls (9 males, 6 females; age = 23.8 ± 5.8 years, height = 171.9 ± 9.9 cm, mass = 68.9 ± 15.5 kg) participated. Intervention(s): Maximum H-reflex (Hmax) and motor wave (Mmax) from the soleus and fibularis longus were recorded while participants lay prone and then stood in unipedal stance. We assessed postural tasks of unipedal stance with participants' eyes closed for 10 seconds using a forceplate. Main Outcome Measure(s): We normalized Hmax to Mmax to obtain Hmax : Mmax ratios for the 2 positions. For each muscle, H-reflex modulation was quantified using the percentage change scores in Hmax : Mmax ratios calculated from prone position to unipedal stance. Center-of-pressure data were used to compute 4 time-to-boundary variables. Separate independent-samples t tests were performed to determine group differences. Pearson product moment correlation coefficients were calculated between the modulation and balance measures in the CAI group. Results: The CAI group presented less H-reflex modulation in the soleus (t26 = −3.77, P = .001) and fibularis longus (t25 = −2.59, P = .02). The mean of the time-to-boundary minima in the anteroposterior direction was lower in the CAI group (t28 = −2.06, P = .048

  19. Modification of Spastic Stretch Reflexes at the Elbow by Flexion Synergy Expression in Individuals With Chronic Hemiparetic Stroke.

    Science.gov (United States)

    McPherson, Jacob G; Stienen, Arno H; Drogos, Justin M; Dewald, Julius P

    2018-03-01

    To systematically characterize the effect of flexion synergy expression on the manifestation of elbow flexor stretch reflexes poststroke, and to relate these findings to elbow flexor stretch reflexes in individuals without neurologic injury. Controlled cohort study. Academic medical center. Participants (N=20) included individuals with chronic hemiparetic stroke (n=10) and a convenience sample of individuals without neurologic or musculoskeletal injury (n=10). Participants with stroke were interfaced with a robotic device that precisely manipulated flexion synergy expression (by regulating shoulder abduction loading) while delivering controlled elbow extension perturbations over a wide range of velocities. This device was also used to elicit elbow flexor stretch reflexes during volitional elbow flexor activation, both in the cohort of individuals with stroke and in a control cohort. In both cases, the amplitude of volitional elbow flexor preactivation was matched to that generated involuntarily during flexion synergy expression. The amplitude of short- and long-latency stretch reflexes in the biceps brachii, assessed by electromyography, and expressed as a function of background muscle activation and stretch velocity. Increased shoulder abduction loading potentiated elbow flexor stretch reflexes via flexion synergy expression in the paretic arm. Compared with stretch reflexes in individuals without neurologic injury, paretic reflexes were larger at rest but were approximately equal to control muscles at matched levels of preactivation. Because flexion synergy expression modifies stretch reflexes in involved muscles, interventions that reduce flexion synergy expression may confer the added benefit of reducing spasticity during functional use of the arm. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Subjectivity and Reflexivity in Qualitative Research—The FQS Issues

    Directory of Open Access Journals (Sweden)

    Katja Mruck

    2003-05-01

    Full Text Available By publishing two FQS issues on "Subjectivity and Reflexivity in Qualitative Research," we address a topic that is central for modern science. On the one hand, there are many demands from philosophy of science and there are numerous methods that aim at eliminating researchers' impact on the research process except in controlled treatments. On the other hand, the insight spread that researchers, in continuously interacting with those being researched, inevitably influence and structure research processes and their outcomes—through their personal and professional characteristics, by leaning on theories and methods available at a special time and place in their (sub- cultures, disciplines and nations. This is especially (but not exclusively true for qualitative research, because qualitative methods are less structured than quantitative methods, and qualitative researchers interact for most part very closely with research participants in their respective research fields. Are there any ways out of the dilemma between the hope of arriving at non-contaminated, valid, and reliable knowledge, on the one hand, and the threat of collecting trivial data, producing (unintentionally autobiographies, or repeating the same cultural prejudices prominent at a time or place, on the other hand? The articles that we introduce here attempt to give some (often provisional answers: by discussing more principally the relevance of subjectivity and reflexivity in and to the process of scientific knowledge construction and by offering possible theoretical frameworks; by examining the research process, using own empirical examples to show in which way (sub- cultural, social, professional, biographical, and personal characteristics influence what is perceived, interpreted and published; and by providing tools that can be used to highlight subjectivity in the research process in order to achieve new levels of understanding through reflexivity. We published the FQS 3(2 and

  1. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H; Arendt-Nielsen, L; Mosbech, H

    2010-01-01

    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...

  2. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H.; Arendt-Nielsen, Lars; Mosbech, H.

    2010-01-01

    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 development of the pupillary light reflex and menace response in neonatal lambs and kids.

    Science.gov (United States)

    Raoofi, Afshin; Mirfakhraie, Pejman; Yourdkhani, Sorush

    2011-03-01

    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.

  4. Lower Amplitude of the Hoffmann Reflex in Women With Patellofemoral Pain: Thinking Beyond Proximal, Local, and Distal Factors.

    Science.gov (United States)

    de Oliveira Silva, Danilo; Magalhães, Fernando Henrique; Faria, Nathálie Clara; Pazzinatto, Marcella Ferraz; Ferrari, Deisi; Pappas, Evangelos; de Azevedo, Fábio Mícolis

    2016-07-01

    To investigate whether vastus medialis (VM) Hoffmann reflexes (H-reflexes) differ on the basis of the presence or absence of patellofemoral pain (PFP) and to assess the capability of VM H-reflex measurements in accurately discriminating between women with and without PFP. Cross-sectional study. Laboratory of biomechanics and motor control. Women (N=30) aged 18 to 35 years were recruited, consisting of 2 groups: women with PFP (n=15) and asymptomatic controls (n=15). Not applicable. Maximum evoked responses were obtained by electrical stimulation applied to the femoral nerve, and peak-to-peak amplitudes of maximal Hoffmann reflex (Hmax) and maximal motor wave (Mmax) ratios were calculated. Independent samples t tests were performed to identify differences between groups, and a receiver operating characteristic curve was constructed to assess the discriminatory capability of VM H-reflex measurements. VM Hmax/Mmax ratios were significantly lower in participants with PFP than in pain-free participants (P=.007). In addition, the VM Hmax/Mmax ratios presented large and balanced discriminatory capability values (sensitivity, 73%; specificity, 67%). This study is the first to show that VM H-reflexes are lower in women with PFP than in asymptomatic controls. Therefore, increasing the excitation of the spinal cord in PFP participants may be essential to maintaining the gains acquired during the rehabilitation programs. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. Plant growth regulator interactions in physiological processes for controlling plant regeneration and in vitro development of Tulbaghia simmleri

    Czech Academy of Sciences Publication Activity Database

    Kumari, A.; Baskaran, P.; Plačková, Lenka; Omámiková, Hana; Nisler, Jaroslav; Doležal, Karel; Van Staden, J.

    2018-01-01

    Roč. 223, APR (2018), s. 65-71 ISSN 0176-1617 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Endogenous hormone * Exogenous hormone application * In vitro regeneration * Ornamental and medicinal plant * Physiological process * Tulbaghia simmleri Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 3.121, year: 2016

  6. Regulatory Physiology

    Science.gov (United States)

    Lane, Helen W.; Whitson, Peggy A.; Putcha, Lakshmi; Baker, Ellen; Smith, Scott M.; Stewart, Karen; Gretebeck, Randall; Nimmagudda, R. R.; Schoeller, Dale A.; Davis-Street, Janis

    1999-01-01

    As noted elsewhere in this report, a central goal of the Extended Duration Orbiter Medical Project (EDOMP) was to ensure that cardiovascular and muscle function were adequate to perform an emergency egress after 16 days of spaceflight. The goals of the Regulatory Physiology component of the EDOMP were to identify and subsequently ameliorate those biochemical and nutritional factors that deplete physiological reserves or increase risk for disease, and to facilitate the development of effective muscle, exercise, and cardiovascular countermeasures. The component investigations designed to meet these goals focused on biochemical and physiological aspects of nutrition and metabolism, the risk of renal (kidney) stone formation, gastrointestinal function, and sleep in space. Investigations involved both ground-based protocols to validate proposed methods and flight studies to test those methods. Two hardware tests were also completed.

  7. Mathematical physiology

    CERN Document Server

    Sneyd, James

    2009-01-01

    There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...

  8. Reflexive cartography a new perspective in mapping

    CERN Document Server

    Casti, Emanuela

    2015-01-01

    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...

  9. The Reflexive Principle of Sociological Theorization

    Directory of Open Access Journals (Sweden)

    R T Ubaidullayeva

    2013-12-01

    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.

  10. Human investigations into the exercise pressor reflex

    DEFF Research Database (Denmark)

    Secher, Niels H; Amann, Markus

    2012-01-01

    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....... 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...... 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...

  11. Reversal of functional disorders by aspiration, expiration and cough reflexes and their voluntary counterparts

    Directory of Open Access Journals (Sweden)

    Zoltan eTomori

    2012-12-01

    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.

  12. Evolutionary problems in non-reflexive spaces

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2010-01-01

    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 http://library.utia.cas.cz/separaty/2008/MTR/kruzik-evolutionary problems in non-reflexive spaces.pdf

  13. Blind Evaluation of Body Reflexes and Motor Skills in Learning Disability.

    Science.gov (United States)

    Freides, David; And Others

    1980-01-01

    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. 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

    1992-01-01

    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...

  15. Grounded theory research: literature reviewing and reflexivity.

    Science.gov (United States)

    McGhee, Gerry; Marland, Glenn R; Atkinson, Jacqueline

    2007-11-01

    This paper is a report of a discussion of the arguments surrounding the role of the initial literature review in grounded theory. Researchers new to grounded theory may find themselves confused about the literature review, something we ourselves experienced, pointing to the need for clarity about use of the literature in grounded theory to help guide others about to embark on similar research journeys. The arguments for and against the use of a substantial topic-related initial literature review in a grounded theory study are discussed, giving examples from our own studies. The use of theoretically sampled literature and the necessity for reflexivity are also discussed. Reflexivity is viewed as the explicit quest to limit researcher effects on the data by awareness of self, something seen as integral both to the process of data collection and the constant comparison method essential to grounded theory. A researcher who is close to the field may already be theoretically sensitized and familiar with the literature on the study topic. Use of literature or any other preknowledge should not prevent a grounded theory arising from the inductive-deductive interplay which is at the heart of this method. Reflexivity is needed to prevent prior knowledge distorting the researcher's perceptions of the data.

  16. Arakeri’s Reflex: an Alternative Pathway for Dento-Cardiac Reflex Mediated Syncope

    Directory of Open Access Journals (Sweden)

    Veena Arali

    2010-03-01

    Full Text Available Introduction: Dentocardiac reflex, a variant of trigeminocardiac reflex elicited specifically during tooth extraction procedures in den-tal/maxillofacial surgery and is believed to cause syncope with an afferent link mediated by posterior superior alveolar nerve. Another variant of trigeminocardiac reflex which is also of interest to the oral and maxillofacial surgeon is oculocardiac reflex which can be triggered by direct or indirect manipulation of eye globe or muscles around it.The hypothesis: Excessive or injudicious pressure or manipulations around the maxillary first molars during extraction procedure are as-sociated with maximum incidence of bradycardia and hypotension than around incisor/ canine/ third molars. This is because; the pressure on eye globe and ophthalmic rectus muscle is maximum during extraction of first molar than incisor/canine and third molars. This observation led us to postulate an alternative pathway for dentocardiac reflex mediated syncope which may possibly justify the maxillary first molar region as a prone factor for the trigger. Evaluation of the hypothesis: Present hypothesis may not confer the specific factor responsible for switch in autonomic response in syncope origin during the tooth extraction procedure, but may provide a clue to where we should be looking.

  17. The Pivotal Role of the Parieto-Occipital Lobe in Card Game-Induced Reflex Epilepsy: A Voxel-Based Morphometry Study.

    Science.gov (United States)

    Park, Kang Min; Kim, Sung Eun; Lee, Byung In

    2016-01-01

    The pathogenesis of card game-induced reflex epilepsy has not been determined so far. The aim of this study was to evaluate structural abnormalities using voxel-based morphometry (VBM) analysis, which may give some clue about the pathogenesis in card game-induced reflex epilepsy. The 3 subjects were diagnosed with card game-induced reflex epilepsy. Evaluation involved a structured interview to obtain clinical information and brain MRI. In VBM analysis, Statistical Parametric Mapping 8 running on the MATLAB platform was employed to analyze the structural differences between patients with card game-induced reflex epilepsy and age- and sex-matched control subjects. The results of VBM analysis revealed that patients with card game-induced reflex epilepsy had significantly increased gray matter volume in the right occipital and parietal lobe. However, there were no structures with decreased gray matter volume in patients with card game-induced reflex epilepsy compared with control subjects. In addition, we found that the patients with card game-induced reflex epilepsy had onset of seizures in adulthood rather than in adolescence, and all of the patients were men. The parieto-occipital lobes might be partially involved in the neuronal network responsible for card game-induced reflex epilepsy. © 2016 S. Karger AG, Basel.

  18. Exercise physiology

    DEFF Research Database (Denmark)

    Kiens, Bente; Richter, Erik; Wojtaszewski, Jørgen

    2014-01-01

    The passing of Professor Bengt Saltin on September 12, 2014 truly marks the end of an era. As editor of the Journal of Applied Physiology and one of Bengt’s many collaborators and colleagues, I wanted the Journal to celebrate his many seminal contributions by means of an Editorial. Professor Bent...

  19. Fearful imagery in social phobia: generalization, comorbidity, and physiological reactivity.

    Science.gov (United States)

    McTeague, Lisa M; Lang, Peter J; Laplante, Marie-Claude; Cuthbert, Bruce N; Strauss, Cyd C; Bradley, Margaret M

    2009-03-01

    Social phobia has been characterized as a disorder of exaggerated fear of social threat and heightened sensitivity to imagery of social failure. To assess the physiological basis of this description, social phobia patients (n=75) and demographically matched control participants (n=75) imagined neutral and fearful events while acoustic startle probes were occasionally presented and eye-blink responses (orbicularis occuli) recorded. Changes in heart rate, skin conductance level, and facial expressivity were also indexed. In addition to comparing control participants and social phobia patients, the influences of diagnostic subtype (circumscribed, generalized), comorbid depression, and chronicity were assessed. Patients exceeded control participants in startle reflex and autonomic responding during imagery of social threat, whereas the groups evinced commensurate reactivity to contents depicting commonly shared fears (survival threat). Individuals with circumscribed performance phobia were similar to control participants, with the exception of more robust reactions to idiographic, performance fear imagery. In contrast, generalized phobic patients were characterized by longer disorder chronicity and demonstrated heightened sensitivity to a broader range of fear contents. Those with generalized phobia plus comorbid depression showed attenuation of fear-potentiated startle and reported the most protracted social anxiety. Subtypes of social phobia can be objectively distinguished in patterns of physiological reactivity. Furthermore, subtypes vary systematically in chronicity and defensive engagement with the shortest disorder duration (circumscribed phobia) associated with the most robust and focal physiological reactivity, followed by broader defensive sensitivity in more chronic generalized phobia, and finally attenuation of the formerly exaggerated fear potentiation in the comorbidly depressed, the most chronic form.

  20. Combined, but not individual, blockade of ASIC3, P2X, and EP4 receptors attenuates the exercise pressor reflex in rats with freely perfused hindlimb muscles.

    Science.gov (United States)

    Stone, Audrey J; Copp, Steven W; Kim, Joyce S; Kaufman, Marc P

    2015-12-01

    In healthy humans, tests of the hypothesis that lactic acid, PGE2, or ATP plays a role in evoking the exercise pressor reflex proved controversial. The findings in humans resembled ours in decerebrate rats that individual blockade of the receptors to lactic acid, PGE2, and ATP had only small effects on the exercise pressor reflex provided that the muscles were freely perfused. This similarity between humans and rats prompted us to test the hypothesis that in rats with freely perfused muscles combined receptor blockade is required to attenuate the exercise pressor reflex. We first compared the reflex before and after injecting either PPADS (10 mg/kg), a P2X receptor antagonist, APETx2 (100 μg/kg), an activating acid-sensing ion channel 3 (ASIC) channel antagonist, or L161982 (2 μg/kg), an EP4 receptor antagonist, into the arterial supply of the hindlimb of decerebrated rats. We then examined the effects of combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the exercise pressor reflex using the same doses, intra-arterial route, and time course of antagonist injections as those used for individual blockade. We found that neither PPADS (n = 5), APETx2 (n = 6), nor L161982 (n = 6) attenuated the reflex. In contrast, combined blockade of these receptors (n = 7) attenuated the peak (↓27%, P reflex. Combined blockade injected intravenously had no effect on the reflex. We conclude that combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the endings of thin fiber muscle afferents is required to attenuate the exercise pressor reflex in rats with freely perfused hindlimbs. Copyright © 2015 the American Physiological Society.

  1. Fermentation pH influences the physiological-state dynamics of Lactobacillus bulgaricus CFL1 during pH-controlled culture.

    Science.gov (United States)

    Rault, Aline; Bouix, Marielle; Béal, Catherine

    2009-07-01

    This study aims at better understanding the effects of fermentation pH and harvesting time on Lactobacillus bulgaricus CFL1 cellular state in order to improve knowledge of the dynamics of the physiological state and to better manage starter production. The Cinac system and multiparametric flow cytometry were used to characterize and compare the progress of the physiological events that occurred during pH 6 and pH 5 controlled cultures. Acidification activity, membrane damage, enzymatic activity, cellular depolarization, intracellular pH, and pH gradient were determined and compared during growing conditions. Strong differences in the time course of viability, membrane integrity, and acidification activity were displayed between pH 6 and pH 5 cultures. As a main result, the pH 5 control during fermentation allowed the cells to maintain a more robust physiological state, with high viability and stable acidification activity throughout growth, in opposition to a viability decrease and fluctuation of activity at pH 6. This result was mainly explained by differences in lactate concentration in the culture medium and in pH gradient value. The elevated content of the ionic lactate form at high pH values damaged membrane integrity that led to a viability decrease. In contrast, the high pH gradient observed throughout pH 5 cultures was associated with an increased energetic level that helped the cells maintain their physiological state. Such results may benefit industrial starter producers and fermented-product manufacturers by allowing them to better control the quality of their starters, before freezing or before using them for food fermentation.

  2. Intralimb and Interlimb Cutaneous Reflexes during Locomotion in the Intact Cat.

    Science.gov (United States)

    Hurteau, Marie-France; Thibaudier, Yann; Dambreville, Charline; Danner, Simon M; Rybak, Ilya A; Frigon, Alain

    2018-04-25

    contacted limb and opposite homologous limb help maintain balance and forward progression. Here, we investigated reflexes during quadrupedal locomotion in the cat by electrically stimulating cutaneous nerves in each of the four limbs. Functionally, responses appear to modify the trajectory or stabilize the movement of the stimulated limb while modifying the support phase of the other limbs. Reflexes between limbs are mediated by fast-conducting pathways that involve excitatory and inhibitory circuits controlling each limb. The comparatively stronger descending pathways from cervical to lumbar circuits controlling the forelimbs and hindlimbs, respectively, could serve a protective function. Copyright © 2018 the authors 0270-6474/18/384104-19$15.00/0.

  3. The relationships between environmental and physiological heat stress indices in Muslim women under the controlled thermal conditions

    Directory of Open Access Journals (Sweden)

    Peymaneh Habibi

    2015-01-01

    Full Text Available Aims: The aim of this study was to evaluate the relationship between environmental and physiological heat stress indices based on heart rate (HR, oral temperature for the estimation of heat strain, in veiled women in hot-dry condition in the climate chamber. Materials and Methods: The experimental study was carried out on 36 healthy Muslim women in hot-dry climatic conditions (wet bulb globe temperature (WBGT = 22-32°C in low workload for 2 h. The HR, oral temperature and WBGT index were measured. The obtained data were analyzed using descriptive statistics and Pearson correlation tests. Results: The results of the Pearson test indicated that physiological strain index was a high correlation (r = 0.975 with WBGT index (P < 0.05. Also, there was a good correlation among WBGT and HR (r = 0.779 and oral temperature (r = 0.981. Conclusion: The findings of this study illustrated that there is a good correlation between environmental and physiological heat stress indices in veiled women with Islamic clothing at the low workload over the action limit (WBGT = 31°C. So that it can be concluded that the WBGT 22-32°C is a good indicator of the heat strain in veiled women with Islamic clothing.

  4. Long-term depression-like plasticity of the blink reflex for the treatment of blepharospasm.

    Science.gov (United States)

    Kranz, Gottfried; Shamim, Ejaz A; Lin, Peter T; Kranz, George S; Hallett, Mark

    2013-04-01

    Our previous work showed a beneficial therapeutic effect on blepharospasm using slow repetitive transcranial magnetic stimulation, which produces a long-term depression (LTD)-like effect. High-frequency supraorbital electrical stimulation, asynchronous with the R2 component of the blink reflex, can also induce LTD-like effects on the blink reflex circuit in healthy subjects. Patients with blepharospasm have reduced inhibition of their blink recovery curves; therefore, a LTD-like intervention might normalize the blink reflex recovery (BRR) and have a favorable therapeutic effect. This is a randomized, sham-controlled, observer-blinded prospective study. In 14 blepharospasm patients, we evaluated the effects of high-frequency supraorbital stimulation on three separate treatment days. We applied 28 trains of nine stimuli, 400 Hz, either before or after the R2 or used sham stimulation. The primary outcome was the blink rate, number of spasms rated by a blinded physician and patient rating before, immediately after and 1 hour after stimulation while resting, reading, and talking; secondary outcome was the BRR. Stimulation "before" and "after" the R2 both showed a similar improvement as sham stimulation in physician rating, but patients felt significantly better with the before condition. Improvement in recovery of the blink reflex was noted only in the before condition. Clinical symptoms differed in the three baseline conditions (resting, reading, and talking). Stimulation before R2 increased inhibition in trigeminal blink reflex circuits in blepharospasm toward normal values and produced subjective, but not objective, improvement. Inhibition of the blink reflex pathway by itself appeared to be insufficient for a useful therapeutic effect. Copyright © 2013 Movement Disorder Society.

  5. 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.

  6. Has dopamine a physiological role in the control of sexual behavior? A critical review of the evidence.

    Science.gov (United States)

    Paredes, Raúl G; Agmo, Anders

    2004-06-01

    The role of dopaminergic systems in the control of sexual behavior has been a subject of study for at least 40 years. Not surprisingly, reviews of the area have been published at variable intervals. However, the earlier reviews have been summaries of published research rather than a critical analysis of it. They have focused upon the conclusions presented in the original research papers rather than on evaluating the reliability and functional significance of the data reported to support these conclusions. During the last few years, important new knowledge concerning dopaminergic systems and their behavioral functions as well as the possible role of these systems in sexual behavior has been obtained. For the first time, it is now possible to integrate the data obtained in studies of sexual behavior into the wider context of general dopaminergic functions. To make this possible, we first present an analysis of the nature and organization of sexual behavior followed by a summary of current knowledge about the brain structures of crucial importance for this behavior. We then proceed with a description of the dopaminergic systems within or projecting to these structures. Whenever possible, we also try to include data on the electrophysiological actions of dopamine. Thereafter, we proceed with analyses of pharmacological data and release studies, both in males and in females. Consistently throughout this discussion, we make an effort to distinguish pharmacological effects on sexual behavior from a possible physiological role of dopamine. By pharmacological effects, we mean here drug-induced alterations in behavior that are not the result of the normal actions of synaptically released dopamine in the untreated animal. The conclusion of this endeavor is that pharmacological effects of dopaminergic drugs are variable in both males and females, independently of whether the drugs are administered systemically or intracerebrally. We conclude that the pharmacological data

  7. Reductions in dead space ventilation with nasal high flow depend on physiological dead space volume: metabolic hood measurements during sleep in patients with COPD and controls.

    Science.gov (United States)

    Biselli, Paolo; Fricke, Kathrin; Grote, Ludger; Braun, Andrew T; Kirkness, Jason; Smith, Philip; Schwartz, Alan; Schneider, Hartmut

    2018-05-01

    Nasal high flow (NHF) reduces minute ventilation and ventilatory loads during sleep but the mechanisms are not clear. We hypothesised NHF reduces ventilation in proportion to physiological but not anatomical dead space.11 subjects (five controls and six chronic obstructive pulmonary disease (COPD) patients) underwent polysomnography with transcutaneous carbon dioxide (CO 2 ) monitoring under a metabolic hood. During stable non-rapid eye movement stage 2 sleep, subjects received NHF (20 L·min -1 ) intermittently for periods of 5-10 min. We measured CO 2 production and calculated dead space ventilation.Controls and COPD patients responded similarly to NHF. NHF reduced minute ventilation (from 5.6±0.4 to 4.8±0.4 L·min -1 ; pspace ventilation (from 2.5±0.4 to 1.6±0.4 L·min -1 ; pspace ventilation correlated with baseline physiological dead space fraction (r 2 =0.36; pspace volume.During sleep, NHF decreases minute ventilation due to an overall reduction in dead space ventilation in proportion to the extent of baseline physiological dead space fraction. Copyright ©ERS 2018.

  8. [Effects of morphine on pupillary light reflex in monkeys].

    Science.gov (United States)

    Meng, Zhi-Qiang; Zhang, Yu-Hua; Chen, Nan-Hui; Miao, Ying-Da; Hu, Xin-Tian; Ma, Yuan-Ye

    2010-06-01

    The pupil size of both human and other animals can be affected by light. Many kinds of psychiatrical and psychological disorders, such as drug abuse, associate with abnormal properties of pupillary light reflex. Thus, the properties of pupillary light reflex could serve as an indicator for drug abuse detection. However, the effect of drug abuse on pupillary light reflex is till unclear. To assess the effects of addictive drugs on pupillary light reflex quantificationally, in the present study, we examined the effects of morphine on pupil diameter and pupillary light reflex in rhesus monkeys. By measuring the pupil diameter at different timing points before and after the administration of morphine, we found that morphine administration reduced the diameter of pupil and decreased the constriction rate. Our present results provide an experimental support for applying the properties of pupillary light reflex as a reference in addicts' detection.

  9. Environmental physiology

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Summaries of research projects conducted during 1978 and 1979 are presented. Subject areas include: the effects of environmental pollutants on homeostasis of the hematopoietic system; pollutant effects on steroid metabolism; pollutant effects on pulmonary macrophages; effects of toxic gases on lung cells; the development of immunological methods for assessing lung damage at the cellular level; the response of erythropoietin concentration to various physiological changes; and the study of actinide metabolism in monkey skeletons

  10. Reflex peripheral vasoconstriction is diminished in older men.

    Science.gov (United States)

    Kenney, W L; Armstrong, C G

    1996-02-01

    The purpose of this study was to compare reflex control of limb blood flow in healthy young (Y; 26 +/- 2 yr) and older (O;61 +/- 2 yr) men during whole body cooling under resting conditions. To better isolate the effect of chronological age, the two age groups (n = 6 per group) were closely matched for maximal oxygen uptake, body surface area, skinfold thickness, and fat-free weight. Subjects sat in an environmentally controlled chamber clad in standardized (0.6-clo) light cotton clothing at a dry-bulb temperature (Tdb) of 28 degrees C. After 30 min, Tdb was decreased by 2 degrees C every 5 min until Tdb = 10 degrees C, where it was held constant for the remainder of the 120-min session. Esophageal and mean skin temperatures were monitored continuously. Forearm blood flow (FBF) was measured every 5 min by venous occlusion plethysmography by using a mercury-in-Silastic strain gauge while arm temperature between the wrist and elbow was clamped at 37.2 +/- 0.1 degrees C by localized warm air heating. In this way, limb vasoconstriction was driven solely by thermoregulatory reflexes and not by direct effects of localized cooling. Mean skin temperature decreased at a similar rate and to a similar extent (by approximately 6 degrees C over a 2-h period) in both age groups, whereas esophageal temperature was relatively unaffected. In response to the local heating, the Y group maintained a significantly higher FBF than did the O group during the initial 30 min but decreased FBF during the cooling phase at a greater rate and to a greater extent than did the O group, leading to a significantly lower FBF during the final 30 min (at Tdb = 10 degrees C). Because there was no age difference in the mean arterial pressure response, similar effects of age were seen on forearm vascular conductance (FBF/mean arterial pressure). It was concluded that older men have a diminished reflex limb vasoconstrictor response to skin cooling. Furthermore, this difference in control of peripheral

  11. Increased Prepulse Inhibition and Sensitization of the Startle Reflex in Autistic Children

    DEFF Research Database (Denmark)

    Madsen, Gitte Falcher; Bilenberg, Niels; Cantio, Cathriona

    2014-01-01

    The relation between autism spectrum disorders (ASD) and schizophrenia is a subject of intense debate and research due to evidence of common neurobiological pathways in the two disorders. The objective of this study was to explore whether deficits in prepulse inhibition (PPI) of the startle reflex......, as usually seen in schizophrenic patients, can be replicated in a group of children with ASD in comparison with a group of matched neuro-typically developed (NTD) controls. An additional aim was to explore possible psychophysiological subgroups within our ASD sample. In a case-control design, 35 ASD patients...... and 40 matched NTD controls were tested in a psychophysiological test battery. The PPI of the acoustic startle reflex was analyzed in 18 ASD subjects and 34 NTD controls. Habituation and sensitization were analyzed in 23 ASD subjects and 39 NTD controls. In trials with less intense prestimuli (76 d...

  12. Relationship between vomiting reflex during esophagogastroduodenoscopy and dyspepsia symptoms.

    Science.gov (United States)

    Enomoto, Shotaro; Watanabe, Mika; Yoshida, Takeichi; Mukoubayashi, Chizu; Moribata, Kosaku; Muraki, Yosuke; Shingaki, Naoki; Deguchi, Hisanobu; Ueda, Kazuki; Inoue, Izumi; Maekita, Takao; Iguchi, Mikitaka; Tamai, Hideyuki; Kato, Jun; Fujishiro, Mitsuhiro; Oka, Masashi; Mohara, Osamu; Ichinose, Masao

    2012-09-01

    Although frequent vomiting reflexes during esophagogastroduodenoscopy (EGD) causes suffering in patients, very few studies have investigated the characteristics of subjects who frequently develop vomiting reflexes. This study examined the incidence of the vomiting reflex and related factors, especially upper gastrointestinal symptoms, among individuals undergoing transoral EGD. Subjects included 488 consecutive adults (mean age, 56.1 ± 8.9 years) who underwent transoral EGD for gastric cancer screening between February 2010 and March 2011. All procedures were performed by an endoscopist with 15 years of experience. Based on a questionnaire survey using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), symptoms (dyspepsia and acid reflux symptoms) and the number of vomiting reflexes during EGD were recorded. Of the 488 subjects, 271 (56%) developed vomiting reflexes (mean, 4.2 times). This reflex-positive group was younger (54.3 ± 9.5 years) than the reflex-negative group (58.3 ± 7.7 years, P reflex-positive group with a high FSSG dyspepsia score (2.27 ± 2.57 vs 1.23 ± 1.84; P acid reflux symptom score (1.96 ± 2.22 vs 1.34 ± 2.14; P reflex-negative group. Multivariate analysis also showed a significant correlation between these four factors and the occurrence of vomiting reflexes. Using an FSSG dyspepsia score of 1 as the cut-off offered 68% sensitivity and 57% specificity for predicting the occurrence of vomiting reflexes. Based on FSSG questionnaire responses on upper gastrointestinal symptoms, dyspepsia symptoms, in particular, are related to presence of vomiting reflexes during EGD. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

  13. Child-Computer Interaction at the Beginner Stage of Music Learning: Effects of Reflexive Interaction on Children's Musical Improvisation.

    Science.gov (United States)

    Addessi, Anna Rita; Anelli, Filomena; Benghi, Diber; Friberg, Anders

    2017-01-01

    In this article children's musical improvisation is investigated through the "reflexive interaction" paradigm. We used a particular system, the MIROR-Impro, implemented in the framework of the MIROR project (EC-FP7), which is able to reply to the child playing a keyboard by a "reflexive" output, mirroring (with repetitions and variations) her/his inputs. The study was conducted in a public primary school, with 47 children, aged 6-7. The experimental design used the convergence procedure, based on three sample groups allowing us to verify if the reflexive interaction using the MIROR-Impro is necessary and/or sufficient to improve the children's abilities to improvise. The following conditions were used as independent variables: to play only the keyboard, the keyboard with the MIROR-Impro but with not-reflexive reply, the keyboard with the MIROR-Impro with reflexive reply. As dependent variables we estimated the children's ability to improvise in solos, and in duets. Each child carried out a training program consisting of 5 weekly individual 12 min sessions. The control group played the complete package of independent variables; Experimental Group 1 played the keyboard and the keyboard with the MIROR-Impro with not-reflexive reply; Experimental Group 2 played only the keyboard with the reflexive system. One week after, the children were asked to improvise a musical piece on the keyboard alone (Solo task), and in pairs with a friend (Duet task). Three independent judges assessed the Solo and the Duet tasks by means of a grid based on the TAI-Test for Ability to Improvise rating scale. The EG2, which trained only with the reflexive system, reached the highest average results and the difference with EG1, which did not used the reflexive system, is statistically significant when the children improvise in a duet. The results indicate that in the sample of participants the reflexive interaction alone could be sufficient to increase the improvisational skills, and necessary

  14. The legacy of care as reflexive learning.

    Science.gov (United States)

    García, Marta Rodríguez; Moya, Jose Luis Medina

    2016-06-14

    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

  15. Acute Whole-Body Vibration does not Facilitate Peak Torque and Stretch Reflex in Healthy Adults

    Directory of Open Access Journals (Sweden)

    Ella W. Yeung

    2013-03-01

    Full Text Available The acute effect of whole-body vibration (WBV training may enhance muscular performance via neural potentiation of the stretch reflex. The purpose of this study was to investigate if acute WBV exposure affects the stretch induced knee jerk reflex [onset latency and electromechanical delay (EMD] and the isokinetic knee extensor peak torque performance. Twenty-two subjects were randomly assigned to the intervention or control group. The intervention group received WBV in a semi-squat position at 30° knee flexion with an amplitude of 0.69 mm, frequency of 45 Hz, and peak acceleration of 27.6 m/s2 for 3 minutes. The control group underwent the same semii-squatting position statically without exposure of WBV. Two-way mixed repeated measures analysis of variance revealed no significant group effects differences on reflex latency of rectus femoris (RF and vastus lateralis (VL; p = 0.934 and 0.935, respectively EMD of RF and VL (p = 0.474 and 0.551, respectively and peak torque production (p = 0.483 measured before and after the WBV. The results of this study indicate that a single session of WBV exposure has no potentiation effect on the stretch induced reflex and peak torque performance in healthy young adults.

  16. Reflexive Aero Structures for Enhanced Survivability, Phase II

    Data.gov (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...

  17. [New theory of holistic integrative physiology and medicine. III: New insight of neurohumoral mechanism and pattern of control and regulation for core axe of respiration, circulation and metabolism].

    Science.gov (United States)

    Sun, Xing-guo

    2015-07-01

    Systemic mechanism of neurohumoral control and regulation for human is limited. We used the new theory of holistic integrative physiology and medicine to approach the mechanism and pattern of neurohumoral control and regulation for life. As the core of human life, there are two core axes of functions. The first one is the common goal of respiration and circulation to transport oxygen and carbon dioxide for cells, and the second one is the goal of gastrointestinal tract and circulation to transport energy material and metabolic product for cells. These two core axes maintain the metabolism. The neurohumoral regulation is holistically integrated and unified for all functions in human body. We simplified explain the mechanism of neurohumoral control and regulation life (respiration and circulation) as the example pattern of sound system. Based upon integrated regulation of life, we described the neurohumoral pattern to control respiration and circulation.

  18. The Disappearing Audience and Reflexive Visibility

    OpenAIRE

    Katerina Girginova

    2016-01-01

    Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an ac...

  19. Scrutinizing the Reflexive Ethnography of Urban Outcast

    DEFF Research Database (Denmark)

    Schultz Larsen, Troels

    2016-01-01

    The core of Bourdieu and Wacquant’s ‘epistemic reflexivity’ demands an embodied reflexivity which takes up the point of view of the practice and the social problems under study via a reflection and reconstruction of the point of view of the ethnographer as an agent embedded in a scientific practice...... in the scientific field. This must be done to cast light over the social conditions and conditionings that have a possible effect on the construction of the given scientific object under study. However, measured by these standards, Urban Outcasts remains not as pedagogical as one might wish. Despite all...

  20. Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls.

    Science.gov (United States)

    Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Fox, Elaine

    2009-10-01

    Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m(2) to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double-blind conditions were analyzed. Overall, cognitive functioning was not affected by short-term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks.

  1. Bidirectional interactions between the baroreceptor reflex and arousal: an update.

    Science.gov (United States)

    Silvani, Alessandro; Calandra-Buonaura, Giovanna; Benarroch, Eduardo E; Dampney, Roger A L; Cortelli, Pietro

    2015-02-01

    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.

  2. Reflexivity in the Interstices: A Tale of Reflexivity at Work in, during, and behind the Scenes

    Science.gov (United States)

    Wickens, Corrine M.; Cohen, James A.; Walther, Carol S.

    2017-01-01

    This article is a story of how the authors came to make sense of the significance of those words in relation to gender, race/ethnicity, and citizenship in writing a manuscript about L[subscript 1]L[subscript 2] acquisition. It is a tale about how Reflexivity wove itself into the conversations, into the writing, into the in-between spaces, the…

  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.

    1990-01-01

    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. The effect of mindfulness meditation on cough reflex sensitivity.

    Science.gov (United States)

    Young, E C; Brammer, C; Owen, E; Brown, N; Lowe, J; Johnson, C; Calam, R; Jones, S; Woodcock, A; Smith, J A

    2009-11-01

    Chronic cough is common, and medical treatment can be ineffective. Mindfulness is a psychological intervention that aims to teach moment-to-moment non-judgemental awareness of thoughts, feelings and sensations. 30 healthy subjects and 30 patients with chronic cough were studied in two sequential trials. For both studies, cough reflex sensitivity to citric acid (C5) was measured on two occasions, with urge to cough rated following each inhalation; between challenges subjects were randomised to (1) no intervention, (2) mindfulness or (3) no intervention but modified cough challenge (subjects suppress coughing). For the healthy volunteers, measures were 1 h apart and mindfulness was practised for 15 min. For the patients with chronic cough measures were 1 week apart and mindfulness was practised daily for 30 min. In healthy volunteers, median change (interquartile range (IQR)) in cough reflex sensitivity (logC5) for no intervention, mindfulness and suppression was +1.0 (0.0 to +1.3), +2.0 (+1.0 to +3.0) and +3.0 (+2.8 to +3.0) doubling concentrations (p = 0.003); there were significant reductions for both mindfulness (p = 0.043) and suppression (p = 0.002) over no intervention. In patients with cough, median change (IQR) in logC5 for no intervention, mindfulness training and voluntary suppression was 0.0 (-1.0 to +1.0), +1.0 (-0.3 to +1.0) and +1.0 (+1.0 to +2.0) doubling concentrations (p = 0.046); there was a significant reduction for suppression (p = 0.02) but not mindfulness (p = 0.35). Urge to cough did not change after mindfulness compared with control in either healthy subjects (p = 0.33) or those with chronic cough (p = 0.47). Compared with control, mindfulness decreased cough reflex sensitivity in healthy volunteers, but did not alter cough threshold in patients with chronic cough. Both groups were able to suppress cough responses to citric acid inhalation.

  5. Ivane S. Beritashvili (1884-1974): from spinal cord reflexes to image-driven behavior.

    Science.gov (United States)

    Tsagareli, M G; Doty, R W

    2009-10-20

    Ivane Beritashvili ("Beritoff" in Russian, and often in Western languages) was a major figure in 20th-century neuroscience. Mastering the string galvanometer, he founded the electrophysiology of spinal cord reflexes, showing that inhibition is a distinctly different process from excitation, contrary to the concepts of his famous mentor, Wedensky. Work on postural reflexes with Magnus was cut short by World War I, but he later demonstrated that navigation in two-dimensional space without vision is a function solely of the vestibular system rather than of muscle proprioception. Persevering in his experiments despite postwar turmoil he founded an enduring Physiology Institute in Tbilisi, where he pursued an ingenious and extensive investigation of comparative memory in vertebrates. This revealed the unique nature of mammalian memory processes, which he forthrightly called "image driven," and distinguished them unequivocally from those underlying conditional reflexes. For some 30 years the Stalinist terror confined his publications to the Russian language. Work with his colleague, Chichinadze, discovering that memory confined to one cerebral hemisphere could be accessed by the other via a specific forebrain commissure, did reach the West, and ultimately led to recognition of the fascinating "split brain" condition. In the 1950s he was removed from his professorial position for 5 years as being "anti-Pavlovian." Restored to favor, he was honorary president of the "Moscow Colloquium" that saw the foundation of the International Brain Research Organization.

  6. Peripheral venous distension elicits a blood pressure raising reflex in young and middle-aged adults.

    Science.gov (United States)

    Matthews, Evan L; Brian, Michael S; Coyle, Dana E; Edwards, David G; Stocker, Sean D; Wenner, Megan M; Farquhar, William B

    2016-06-01

    Distension of peripheral veins in humans elicits a pressor and sympathoexcitatory response that is mediated through group III/IV skeletal muscle afferents. There is some evidence that autonomic reflexes mediated by these sensory fibers are blunted with increasing age, yet to date the venous distension reflex has only been studied in young adults. Therefore, we tested the hypothesis that the venous distension reflex would be attenuated in middle-aged compared with young adults. Nineteen young (14 men/5 women, 25 ± 1 yr) and 13 middle-aged (9 men/4 women, 50 ± 2 yr) healthy normotensive participants underwent venous distension via saline infusion through a retrograde intravenous catheter in an antecubital vein during limb occlusion. Beat-by-beat blood pressure, muscle sympathetic nerve activity (MSNA), and model flow-derived cardiac output (Q), and total peripheral resistance (TPR) were recorded throughout the trial. Mean arterial pressure (MAP) increased during the venous distension in both young (baseline 83 ± 2, peak 94 ± 3 mmHg; P blood pressure, MSNA, and TPR were similar between young and middle-aged adults. Additionally, no correlation was found between age and the response to venous distension (all P > 0.05). These findings suggest that peripheral venous distension elicits a pressor and sympathetic response in middle-aged adults similar to the response observed in young adults. Copyright © 2016 the American Physiological Society.

  7. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping.

    Science.gov (United States)

    Schumacher, Christian; Seyfarth, André

    2017-01-01

    In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB), velocity (VFB) and force feedback (FFB) pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort). Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map . The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency). Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length) or environmental parameters (ground compliance). Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a specific

  8. Occupational physiology

    CERN Document Server

    Toomingas, Allan; Tornqvist, Ewa Wigaeus

    2011-01-01

    In a clear and accessible presentation, Occupational Physiology focuses on important issues in the modern working world. Exploring major public health problems-such as musculoskeletal disorders and stress-this book explains connections between work, well-being, and health based on up-to-date research in the field. It provides useful methods for risk assessment and guidelines on arranging a good working life from the perspective of the working individual, the company, and society as a whole.The book focuses on common, stressful situations in different professions. Reviewing bodily demands and r

  9. Differential controls by climate and physiology over the emission rates of biogenic volatile organic compounds from mature trees in a semi-arid pine forest.

    Science.gov (United States)

    Eller, Allyson S D; Young, Lindsay L; Trowbridge, Amy M; Monson, Russell K

    2016-02-01

    Drought has the potential to influence the emission of biogenic volatile organic compounds (BVOCs) from forests and thus affect the oxidative capacity of the atmosphere. Our understanding of these influences is limited, in part, by a lack of field observations on mature trees and the small number of BVOCs monitored. We studied 50- to 60-year-old Pinus ponderosa trees in a semi-arid forest that experience early summer drought followed by late-summer monsoon rains, and observed emissions for five BVOCs-monoterpenes, methylbutenol, methanol, acetaldehyde and acetone. We also constructed a throughfall-interception experiment to create "wetter" and "drier" plots. Generally, trees in drier plots exhibited reduced sap flow, photosynthesis, and stomatal conductances, while BVOC emission rates were unaffected by the artificial drought treatments. During the natural, early summer drought, a physiological threshold appeared to be crossed when photosynthesis ≅2 μmol m(-2) s(-1) and conductance ≅0.02 mol m(-2) s(-1). Below this threshold, BVOC emissions are correlated with leaf physiology (photosynthesis and conductance) while BVOC emissions are not correlated with other physicochemical factors (e.g., compound volatility and tissue BVOC concentration) that have been shown in past studies to influence emissions. The proportional loss of C to BVOC emission was highest during the drought primarily due to reduced CO2 assimilation. It appears that seasonal drought changes the relations among BVOC emissions, photosynthesis and conductance. When drought is relaxed, BVOC emission rates are explained mostly by seasonal temperature, but when seasonal drought is maximal, photosynthesis and conductance-the physiological processes which best explain BVOC emission rates-decline, possibly indicating a more direct role of physiology in controlling BVOC emission.

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

    Directory of Open Access Journals (Sweden)

    Michael eFrazier

    2015-10-01

    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.

  11. Cough reflex sensitization from esophagus and nose.

    Science.gov (United States)

    Hennel, Michal; Brozmanova, Mariana; Kollarik, Marian

    2015-12-01

    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 (pH acidic reflux such as receptors highly sensitive to acid and receptors for bile acids. The nature of sensory pathways from the nose and their activators relevant for cough 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    International Nuclear Information System (INIS)

    Hans-Dieter Reidenbach

    2006-01-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  13. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    Energy Technology Data Exchange (ETDEWEB)

    Hans-Dieter Reidenbach [Cologne University of Applied Sciences Research Laboratory on Medical Technology/HLT Betzdorfer Str. 2, 50679 Koeln (Germany)

    2006-07-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  14. The role of acupuncture in the treatment of prosthodontic patients with a gagging reflex

    OpenAIRE

    Raghad Hashim; Reem Shaltoni; Luma Kamal; Faten Khanfar

    2017-01-01

    Aim and Objectives: Hyperactive gag reflex (GR) can be a big obstacle in certain dental procedures especially in making an upper arch impression. Treating those might be a challenge for both the dentist and the patient. Many patients withdraw from treatment because of their inability to cope with the procedure. One of the effective modalities in controlling this phenomenon is the use of Acupuncture. In this trial, Ear acupuncture was used aiming to control hyperactive GR during upper alginate...

  15. Avian reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

    1995-01-01

    Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

  16. GABA in nucleus tractus solitarius participates in electroacupuncture modulation of cardiopulmonary bradycardia reflex.

    Science.gov (United States)

    Tjen-A-Looi, Stephanie C; Guo, Zhi-Ling; Longhurst, John C

    2014-12-01

    Phenylbiguanide (PBG) stimulates cardiopulmonary receptors and cardiovascular reflex responses, including decreases in blood pressure and heart rate mediated by the brain stem parasympathetic cardiac neurons in the nucleus ambiguus and nucleus tractus solitarius (NTS). Electroacupuncture (EA) at P5-6 stimulates sensory fibers in the median nerve and modulates these reflex responses. Stimulation of median nerves reverses bradycardia through action of γ-aminobutyric acid (GABA) in the nucleus ambiguus, important in the regulation of heart rate. We do not know whether the NTS or the neurotransmitter mechanisms in this nucleus participate in these modulatory actions by acupuncture. We hypothesized that somatic nerve stimulation during EA (P5-6) modulates cardiopulmonary inhibitory responses through a GABAergic mechanism in the NTS. Anesthetized and ventilated cats were examined during either PBG or direct vagal afferent stimulation while 30 min of EA was applied at P5-6. Reflex heart rate and blood pressure responses and NTS-evoked discharge were recorded. EA reduced the PBG-induced depressor and bradycardia reflexes by 67% and 60%, respectively. Blockade of GABAA receptors in the NTS reversed EA modulation of bradycardia but not the depressor response. During EA, gabazine reversed the vagally evoked discharge activity of cardiovascular NTS neurons. EA modulated the vagal-evoked cardiovascular NTS cellular activity for 60 min. Immunohistochemistry using triple labeling showed GABA immunoreactive fibers juxtaposed to glutamatergic nucleus ambiguus-projecting NTS neurons in rats. These glutamatergic neurons expressed GABAA receptors. These findings suggest that EA inhibits PBG-evoked bradycardia and vagally evoked NTS activity through a GABAergic mechanism, likely involving glutamatergic nucleus ambiguus-projecting NTS neurons. Copyright © 2014 the American Physiological Society.

  17. Maternal intake of cashew nuts accelerates reflex maturation and facilitates memory in the offspring.

    Science.gov (United States)

    de Melo, Marília Ferreira Frazão Tavares; Pereira, Diego Elias; Sousa, Morgana Moura; Medeiros, Dilian Maise Ferreira; Lemos, Leanderson Tulio Marques; Madruga, Marta Suely; Santos, Nayane Medeiros; de Oliveira, Maria Elieidy Gomes; de Menezes, Camila Carolina; Soares, Juliana Késsia Barbosa

    2017-10-01

    Essential fatty acids, being indispensable during the stages of pregnancy, lactation and infancy influence the transmission of nerve impulses and brain function, and cashew nuts are a good source of these fatty acids. The objective of this study was to evaluate the effects of cashew nut consumption on reflex development, memory and profile of fatty acids of rat offspring treated during pregnancy and lactation. The animals were divided into three groups: Control (CONT), treated with 7% lipid derived from soybean oil; Normolipidic (NL) treated with 7% lipids derived from cashew nuts; and Hyperlipidic (HL) treated with 20% lipids derived from cashew nuts. Reflex ontogeny, Open-field habituation test and the Object Recognition Test (ORT) were assessed. The profile of fatty acids in the brain was carried out when the animals were zero, 21 and 60days old. Accelerated reflex maturation was observed in animals treated with cashew nuts (pacids and less Docosahexaenoic acid (DHA) in animals of the HL. The data showed that maternal consumption of cashew nuts can accelerate reflex maturation and facilitate memory in offspring when offered in adequate quantities. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  18. Does diurnal variation in cough reflex testing exist in healthy young adults?

    Science.gov (United States)

    Perry, Sarah; Huckabee, Maggie-Lee

    2017-05-01

    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.

  19. Autonomic Dysfunction in Muscular Dystrophy: A Theoretical Framework for Muscle Reflex Involvement

    Directory of Open Access Journals (Sweden)

    Scott Alan Smith

    2014-02-01

    Full Text Available Muscular dystrophies are a heterogeneous group of genetically inherited disorders whose most prominent clinical feature is progressive degeneration of skeletal muscle. In several forms of the disease, the function of cardiac muscle is likewise affected. The primary defect in this group of diseases is caused by mutations in myocyte proteins important to cellular structure and/or performance. That being stated, a growing body of evidence suggests that the development of autonomic dysfunction may secondarily contribute to the generation of skeletal and cardio-myopathy in muscular dystrophy. Indeed, abnormalities in the regulation of both sympathetic and parasympathetic nerve activity have been reported in a number of muscular dystrophy variants. However, the mechanisms mediating this autonomic dysfunction remain relatively unknown. An autonomic reflex originating in skeletal muscle, the exercise pressor reflex, is known to contribute significantly to the control of sympathetic and parasympathetic activity when stimulated. Given the skeletal myopathy that develops with muscular dystrophy, it is logical to suggest that the function of this reflex might also be abnormal with the pathogenesis of disease. As such, it may contribute to or exacerbate the autonomic dysfunction that manifests. This possibility along with a basic description of exercise pressor reflex function in health and disease are reviewed. A better understanding of the mechanisms that possibly underlie autonomic dysfunction in muscular dystrophy may not only facilitate further research but could also lead to the identification of new therapeutic targets for the treatment of muscular dystrophy.

  20. Buriti oil (Mauritia flexuosa L.) negatively impacts somatic growth and reflex maturation and increases retinol deposition in young rats.

    Science.gov (United States)

    Medeiros, Maria C; Aquino, Jailane S; Soares, Juliana; Figueiroa, Edigleide B; Mesquita, Hanni M; Pessoa, Debora C; Stamford, Tania M

    2015-11-01

    Buriti oil contains nutrients such as essential fatty acids and vitamins, which are directly involved with neonates' development. However, the refining process of this oil can change its nutrient profile. This study investigated the effects of maternal consumption of Buriti oil (crude or refined), on reflex and somatic development and retinol levels in neonatal rats. Thirty-six Wistar male neonate rats born from mothers who consumed diet with 7% lipids during gestation and lactation were used. Rats were randomized into three groups: rats receiving diet added of soybean oil (control-CG), crude Buriti oil (CB) and refined Buriti oil (RB). Offspring weight, tail length, reflex ontogeny and somatic maturation were assessed during lactation. At the end of the experiment, serum and liver retinol concentrations were measured. Animals from CB and RB groups showed delayed onset of palm grasp, righting reflex and cliff avoidance reflexes compared to the control group (CG). However, animals from RB group showed anticipation of auditory startle compared to those from BC group. Regarding somatic maturation indicators, animals from RB group showed delayed eye opening and eruption of superior and inferior incisors in relation to control and anticipation in the auditory conduit opening in relation to CB group. Rats from CB and RB groups showed higher serum and liver vitamin A contents. Buriti oil delays physical parameters and reflex maturation and increases serum and liver retinol deposition among neonatal rats. Copyright © 2015. Published by Elsevier Ltd.

  1. GABAergic mechanism mediated via D receptors in the rat periaqueductal gray participates in the micturition reflex: an in vivo microdialysis study.

    Science.gov (United States)

    Kitta, Takeya; Matsumoto, Machiko; Tanaka, Hiroshi; Mitsui, Takahiko; Yoshioka, Mitsuhiro; Nonomura, Katsuya

    2008-06-01

    The periaqueductal gray (PAG) is critically involved in the micturition reflex, but little is known about the neuronal mechanisms involved. The present study elucidated dynamic changes in dopamine (DA), glutamate and gamma-aminobutyric acid (GABA) in the rat PAG during the micturition reflex, with a focus on dopaminergic modulation using in vivo microdialysis combined with cystometrography. Extracellular levels of DA and glutamate increased, whereas levels of GABA decreased, in parallel with the micturition reflex. Application of a D(1) receptor antagonist into the PAG produced increases in maximal voiding pressure (MVP) and decreases in intercontraction interval (ICI), suggesting that the micturition reflex was facilitated by D(1) receptor blockade. The D(1) receptor antagonist prevented micturition-induced decreases in GABA efflux but had no effect on DA or glutamate. Neither a D(2) receptor antagonist nor a D(1)/D(2) receptor agonist affected these neurochemical and physiological parameters. Micturition-induced inhibition of GABA was not observed in 6-hydroxydopamine (6-OHDA)-lesioned rats, an animal model of Parkinson's disease. 6-OHDA-lesioned rats exhibited bladder hyperactivity evaluated by increases in MVP and decreases in ICI, mimicking facilitation of the micturition reflex induced by D(1) receptor blockade. These findings suggest that the micturition reflex is under tonic dopaminergic regulation through D(1) receptors, in which a GABAergic mechanism is involved. Bladder hyperactivity observed in 6-OHDA-lesioned rats may be caused by dysfunction of GABAergic regulation underlying the micturition reflex. The present findings contribute to our understanding not only of the neurophysiology of the micturition reflex but also of the pathophysiology of lower urinary tract dysfunction in patients with Parkinson's disease.

  2. (Re)constructing Reflexivity: A Relational Constructionist Approach

    NARCIS (Netherlands)

    Hosking, D.M.; Pluut, B.

    2010-01-01

    This article distinguishes three discourses of reflexivity in relation to human inquiry. One of these arises from a post-modern, relational constructionist perspective which radically re-conceptualizes reflexivity: (a) as a local and co-constructed process oriented towards the question (b) how are

  3. 21 CFR 890.1450 - Powered reflex hammer.

    Science.gov (United States)

    2010-04-01

    ... 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...

  4. The Role of Transformational Leadership in Enhancing Team Reflexivity

    NARCIS (Netherlands)

    M.C. Schippers (Michaéla); D.N. den Hartog (Deanne); P.L. Koopman (Paul); D.L. van Knippenberg (Daan)

    2007-01-01

    textabstractTeam reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to

  5. The role of transformational leadership in enhancing team reflexivity

    NARCIS (Netherlands)

    Schippers, M.C.; den Hartog, D.N.; Koopman, P.L.; van Knippenberg, D.

    2008-01-01

    Team reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to develop

  6. The influence of reflexive educational environment on students ...

    African Journals Online (AJOL)

    The influence of reflexive educational environment on students' reflection development in ... based on them) from which, as they integrate, a reflexive personality style is developed. ... (narrative, dialogical, cognitive and axiological) are the factors influencing the outcome of social adaptation. ... AJOL African Journals Online.

  7. 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 ...

  8. Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity.

    Science.gov (United States)

    Farrugia, David; Woodman, Dan

    2015-12-01

    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.

  9. Physiology for engineers applying engineering methods to physiological systems

    CERN Document Server

    Chappell, Michael

    2016-01-01

    This book provides an introduction to qualitative and quantitative aspects of human physiology. It looks at biological and physiological processes and phenomena, including a selection of mathematical models, showing how physiological problems can be mathematically formulated and studied. It also illustrates how a wide range of engineering and physics topics, including electronics, fluid dynamics, solid mechanics and control theory can be used to describe and understand physiological processes and systems. Throughout the text there are introductions to measuring and quantifying physiological processes using both signal and imaging technologies. Physiology for Engineers describes the basic structure and models of cellular systems, the structure and function of the cardiovascular system, the electrical and mechanical activity of the heart and provides an overview of the structure and function of the respiratory and nervous systems. It also includes an introduction to the basic concepts and applications of reacti...

  10. Physiological Acoustics

    Science.gov (United States)

    Young, Eric D.

    The analysis of physiological sound in the peripheral auditory system solves three important problems. First, sound energy impinging on the head must be captured and presented to the transduction apparatus in the ear as a suitable mechanical signal; second, this mechanical signal needs to be transduced into a neural representation that can be used by the brain; third, the resulting neural representation needs to be analyzed by central neurons to extract information useful to the animal. This chapter provides an overview of some aspects of the first two of these processes. The description is entirely focused on the mammalian auditory system, primarily on human hearing and on the hearing of a few commonly used laboratory animals (mainly rodents and carnivores). Useful summaries of non-mammalian hearing are available [1]. Because of the large size of the literature, review papers are referenced wherever possible.

  11. The Ecology of Stress: linking life-history traits with physiological control mechanisms in free-living guanacos.

    Science.gov (United States)

    Ovejero Aguilar, Ramiro J A; Jahn, Graciela A; Soto-Gamboa, Mauricio; Novaro, Andrés J; Carmanchahi, Pablo

    2016-01-01

    Providing the context for the evolution of life-history traits, habitat features constrain successful ecological and physiological strategies. In vertebrates, a key response to life's challenges is the activation of the Stress (HPA) and Gonadal (HPG) axes. Much of the interest in stress ecology is motivated by the desire to understand the physiological mechanisms in which the environment affects fitness. As reported in the literature, several intrinsic and extrinsic factors affect variability in hormone levels. In both social and non-social animals, the frequency and type of interaction with conspecifics, as well as the status in social species, can affect HPA axis activity, resulting in changes in the reproductive success of animals. We predicted that a social environment can affect both guanaco axes by increasing the secretion of testosterone (T) and Glucocorticoid (GCs) in response to individual social interactions and the energetic demands of breeding. Assuming that prolonged elevated levels of GCs over time can be harmful to individuals, it is predicted that the HPA axis suppresses the HPG axis and causes T levels to decrease, as GCs increase. All of the data for individuals were collected by non-invasive methods (fecal samples) to address hormonal activities. This is a novel approach in physiological ecology because feces are easily obtained through non-invasive sampling in animal populations. As expected, there was a marked adrenal ( p -value = .3.4e-12) and gonadal ( p -value = 0.002656) response due to seasonal variation in Lama guanicoe . No significant differences were found in fecal GCs metabolites between males/females*season for the entire study period ( p -value = 0.2839). Despite the seasonal activity variation in the hormonal profiles, our results show a positive correlation ( p -value = 1.952e-11, COR = 0.50) between the adrenal and gonadal system. The marked endocrine ( r 2  = 0.806) and gonad ( r 2  = 0.7231) response due to seasonal

  12. The Ecology of Stress: linking life-history traits with physiological control mechanisms in free-living guanacos

    Directory of Open Access Journals (Sweden)

    Ramiro J.A. Ovejero Aguilar

    2016-11-01

    Full Text Available Background Providing the context for the evolution of life-history traits, habitat features constrain successful ecological and physiological strategies. In vertebrates, a key response to life’s challenges is the activation of the Stress (HPA and Gonadal (HPG axes. Much of the interest in stress ecology is motivated by the desire to understand the physiological mechanisms in which the environment affects fitness. As reported in the literature, several intrinsic and extrinsic factors affect variability in hormone levels. In both social and non-social animals, the frequency and type of interaction with conspecifics, as well as the status in social species, can affect HPA axis activity, resulting in changes in the reproductive success of animals. We predicted that a social environment can affect both guanaco axes by increasing the secretion of testosterone (T and Glucocorticoid (GCs in response to individual social interactions and the energetic demands of breeding. Assuming that prolonged elevated levels of GCs over time can be harmful to individuals, it is predicted that the HPA axis suppresses the HPG axis and causes T levels to decrease, as GCs increase. Methods All of the data for individuals were collected by non-invasive methods (fecal samples to address hormonal activities. This is a novel approach in physiological ecology because feces are easily obtained through non-invasive sampling in animal populations. Results As expected, there was a marked adrenal (p-value = .3.4e−12 and gonadal (p-value = 0.002656 response due to seasonal variation in Lama guanicoe. No significant differences were found in fecal GCs metabolites between males/females*season for the entire study period (p-value = 0.2839. Despite the seasonal activity variation in the hormonal profiles, our results show a positive correlation (p-value = 1.952e−11, COR = 0.50 between the adrenal and gonadal system. The marked endocrine (r2 = 0.806 and gonad (r2 = 0

  13. Prevalence of family history in patients with reflex syncope

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...... 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....... 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...

  14. The Effects of Forest Therapy on Coping with Chronic Widespread Pain: Physiological and Psychological Differences between Participants in a Forest Therapy Program and a Control Group.

    Science.gov (United States)

    Han, Jin-Woo; Choi, Han; Jeon, Yo-Han; Yoon, Chong-Hyeon; Woo, Jong-Min; Kim, Won

    2016-02-24

    This study aimed to investigate the effects of a two-day forest therapy program on individuals with chronic widespread pain. Sixty one employees of a public organization providing building and facilities management services within the Seoul Metropolitan area participated in the study. Participants were assigned to an experimental group (n = 33) who participated in a forest therapy program or a control group (n = 28) on a non-random basis. Pre- and post-measures of heart rate variability (HRV), Natural Killer cell (NK cell) activity, self-reported pain using the visual analog scale (VAS), depression level using the Beck Depression Inventory (BDI), and health-related quality of life measures using the EuroQol Visual Analog Scale (EQ-VAS) were collected in both groups. The results showed that participants in the forest therapy group, as compared to the control group, showed physiological improvement as indicated by a significant increase in some measures of HRV and an increase in immune competence as indicated by NK cell activity. Participants in the forest therapy group also reported significant decreases in pain and depression, and a significant improvement in health-related quality of life. These results support the hypothesis that forest therapy is an effective intervention to relieve pain and associated psychological and physiological symptoms in individuals with chronic widespread pain.

  15. The Effects of Forest Therapy on Coping with Chronic Widespread Pain: Physiological and Psychological Differences between Participants in a Forest Therapy Program and a Control Group

    Directory of Open Access Journals (Sweden)

    Jin-Woo Han

    2016-02-01

    Full Text Available This study aimed to investigate the effects of a two-day forest therapy program on individuals with chronic widespread pain. Sixty one employees of a public organization providing building and facilities management services within the Seoul Metropolitan area participated in the study. Participants were assigned to an experimental group (n = 33 who participated in a forest therapy program or a control group (n = 28 on a non-random basis. Pre- and post-measures of heart rate variability (HRV, Natural Killer cell (NK cell activity, self-reported pain using the visual analog scale (VAS, depression level using the Beck Depression Inventory (BDI, and health-related quality of life measures using the EuroQol Visual Analog Scale (EQ-VAS were collected in both groups. The results showed that participants in the forest therapy group, as compared to the control group, showed physiological improvement as indicated by a significant increase in some measures of HRV and an increase in immune competence as indicated by NK cell activity. Participants in the forest therapy group also reported significant decreases in pain and depression, and a significant improvement in health-related quality of life. These results support the hypothesis that forest therapy is an effective intervention to relieve pain and associated psychological and physiological symptoms in individuals with chronic widespread pain.

  16. The effect of music therapy on depression and physiological parameters in elderly people living in a Turkish nursing home: a randomized-controlled trial.

    Science.gov (United States)

    Gök Ugur, Hacer; Yaman Aktaş, Yeşim; Orak, Oya Sevcan; Saglambilen, Okan; Aydin Avci, İlknur

    2017-12-01

    This study was carried out in an effort to determine the effect of music therapy on depression and physiological parameters in elderly people who were living in a nursing home. The study was a randomized controlled trial. The study sample consisted of 64 elderly people who complied with the criteria of inclusion for the study. The data were collected using the 'Elderly Information Form' and 'Geriatric Depression Scale'. The music group listened to music three days in a week during 8 weeks. The depression levels were assessed at baseline (week 0) and follow-up in the eight week. It was found that the difference between post-test depression scores of the two groups was found to be statistically significant (t = -2.86, p depression level and systolic blood pressure in elderly people. The study results implies that music therapy can be an effective practice for public health and home care nurses attempting to reduce depression and control physiological parameters of elderly people.

  17. Tissue engineering the mechanosensory circuit of the stretch reflex arc: sensory neuron innervation of intrafusal muscle fibers.

    Science.gov (United States)

    Rumsey, John W; Das, Mainak; Bhalkikar, Abhijeet; Stancescu, Maria; Hickman, James J

    2010-11-01

    The sensory circuit of the stretch reflex arc, composed of specialized intrafusal muscle fibers and type Ia proprioceptive sensory neurons, converts mechanical information regarding muscle length and stretch to electrical action potentials and relays them to the central nervous system. Utilizing a non-biological substrate, surface patterning photolithography and a serum-free medium formulation a co-culture system was developed that facilitated functional interactions between intrafusal muscle fibers and sensory neurons. The presence of annulospiral wrappings (ASWs) and flower-spray endings (FSEs), both physiologically relevant morphologies in sensory neuron-intrafusal fiber interactions, were demonstrated and quantified using immunocytochemistry. Furthermore, two proposed components of the mammalian mechanosensory transduction system, BNaC1 and PICK1, were both identified at the ASWs and FSEs. To verify functionality of the mechanoreceptor elements the system was integrated with a MEMS cantilever device, and Ca(2+) currents were imaged along the length of an axon innervating an intrafusal fiber when stretched by cantilever deflection. This system provides a platform for examining the role of this mechanosensory complex in the pathology of myotonic and muscular dystrophies, peripheral neuropathy, and spasticity inducing diseases like Parkinson's. These studies will also assist in engineering fine motor control for prosthetic devices by improving our understanding of mechanosensitive feedback. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Use of a supercontinuum white light in evaluating the spectral sensitivity of the pupil light reflex

    Science.gov (United States)

    Chin, Catherine; Leick, Lasse; Podoleanu, Adrian; Lall, Gurprit S.

    2018-03-01

    We assessed the spectral sensitivity of the pupillary light reflex in mice using a high power super continuum white light (SCWL) source in a dual wavelength configuration. This novel approach was compared to data collected from a more traditional setup using a Xenon arc lamp fitted with monochromatic interference filters. Irradiance response curves were constructed using both systems, with the added benefit of a two-wavelength, equivocal power, output using the SCWL. The variables applied to the light source were intensity, wavelength and stimulus duration through which the physiological output measured was the minimum pupil size attained under such conditions. We show that by implementing the SCWL as our novel stimulus we were able to dramatically increase the physiological usefulness of our pupillometry system.

  19. Pharmacological evaluation of the role of cyclooxygenase isoenzymes on the micturition reflex following experimental cystitis in rats

    Science.gov (United States)

    Lecci, Alessandro; Birder, Lori A; Meini, Stefania; Catalioto, Rose-Marie; Tramontana, Manuela; Giuliani, Sandro; Criscuoli, Marco; Maggi, Carlo A

    2000-01-01

    Prostanoids, generated from cyclooxygenase (COX) isoenzymes, play a role in the physiological function of the lower urinary tract and are important mediators of inflammatory hyperalgesia. The present work evaluates the effects of the COX-1/COX-2 inhibitor dexketoprofen as well as of a selective COX-2 inhibitor, NS-398, on urodynamic function following endotoxin (LPS) or cyclophosphamide (CYP)-induced inflammation of the urinary bladder. The application of arachidonic acid (330 μg rat−1) onto the serosal surface of the urinary bladder in control rats elicited bladder contractions which could be blocked in a dose-dependent manner by dexketoprofen (0.1–3 mg kg−1, i.v.) but not by NS-398 (0.2–6 mg kg−1, i.v.). Dexketoprofen (3 mg kg−1, i.v.) decreased the micturition frequency and increased the pressure threshold for triggering the micturition either when administered within 15 min or 3 h following surgery in control animals. NS-398 (6 mg kg−1, i.v.) decreased the micturition frequency and increased the pressure threshold when administered 3 h but not 15 min following surgery. Administration of LPS (2 mg kg−1, i.v., 90–120 min) increased both the micturition frequency and the pressure threshold for triggering the micturition reflex. Changes in urodynamic parameters induced by LPS were prevented by doses of either dexketoprofen (1 mg kg−1, i.v.) or NS-398 (2 mg kg−1, i.v.) which were ineffective in control animals. Pretreatment with CYP (150 mg kg−1, i.p., 48 h) increased the micturition frequency, pressure threshold, and the minimal intravesical pressure but decreased the mean amplitude of micturition contractions. In CYP-treated rats, dexketoprofen (1 mg kg−1, i.v.) or NS-398 (2 mg kg−1, i.v.) blocked the CYP-induced urodynamic changes with exception of the micturition contraction amplitude. These results indicate that COX-1 may be involved in modulating the threshold for activating the

  20. Reflex sympathetic dystrophy syndrome: MR imaging study

    International Nuclear Information System (INIS)

    Masciocchi, C.; Fascetti, E.; Bonanni, G.; Calvisi, V.; Buoni, C.; Passariello, R.

    1987-01-01

    Reflex sympathetic dystrophy syndrome (RSDS) is characterized by pain, swelling, and limitation of motion. The etiology and pathophysiology mechanism have not yet been identified. We considered eight patients with clinical signs of RSDS, in five cases located at the knee joint and in three cases in the hip. In all cases conventional radiography and radionuclide bone scanning were performed before MR imaging. Conventional radiography was negative in three cases while scintigraphy demonstrated the lesion in all patients. MR imaging showed an area of low intensity signal on T1-weighted scans and an increased signal intensity on T2-weighted images. This area is located at the bone marrow and its regular and homogeneous. This specific finding on MR images is due to reflect edema by hyperemia of the bone marrow. The MR imaging diagnosis was confirmed on clinical and radiological follow-up. MR imaging can have a role in the differential diagnosis when other studies are nondiagnostic or nonspecific for RSDS

  1. Is there a hierarchy of survival reflexes?

    Science.gov (United States)

    Macphail, Kieran

    2013-10-01

    A hierarchy of survival reflexes for prioritising assessment and treatment in patients with pain of insidious onset is hypothesised. The hierarchy asserts that some systems are more vital than others and that the central nervous system (CNS) prioritises systems based on their significance to survival. The hypothesis suggests that dysfunction in more important systems will cause compensation in less important systems. This paper presents studies examining these effects for each system, arguing that each section of the hierarchy may have effects on other systems within the hierarchy. This concept is untested empirically, highly speculative and substantial research is required to validate the suggested hierarchical prioritisation by the CNS. Nonetheless, the hierarchy does provide a theoretical framework to use to exclude contributing systems in patients with pain of insidious onset. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Vestibular-ocular accommodation reflex in man

    Science.gov (United States)

    Clark, B.; Randle, R. J.; Stewart, J. D.

    1975-01-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present paper studies a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 sec of rotating. Accommodation was recorded continuously on an infrared optometer for 110 sec under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  3. Reflexive regulation of CSR to promote sustainability

    DEFF Research Database (Denmark)

    Buhmann, Karin

    2011-01-01

    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......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...... 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...

  4. Reflexive regulation of CSR to promote sustainablility

    DEFF Research Database (Denmark)

    Buhmann, Karin

    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......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...... 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...

  5. Reflexivity and vulnerability in collaborative knowledge production

    DEFF Research Database (Denmark)

    Jakobsen, Helle Nordentoft; Olesen, Birgitte Ravn

    -reports of positive learning outcomes and fails to illuminate how power is always at play leaving certain participants exposed and potentially vulnerable (Fenwick, 2008). As such, it remains unclear how power relations unfold in moment-by-moment interactions including how the researcher’s position matters...... because their voices are subjugated and they appear to be vulnerable. The extent of this development in the peer interactions and the reproductive nature of the knowledge produced were unexpected. In other words we – the researchers – became struck in the analytical process. In the final part of the paper......, we discuss how the reproduction of power relations invokes ethical concerns and raises critical perspectives on the undeniable common good of collaborative research in which participants’ vulnerability may be overlooked in potentially reflexive moments (Nordentoft and Kappel, 2011). Still, we find...

  6. The Disappearing Audience and Reflexive Visibility

    Directory of Open Access Journals (Sweden)

    Katerina Girginova

    2016-08-01

    Full Text Available Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an activity that is of utmost importance not only to researchers wishing to “see” various audiences but also for audiences writ large, wishing to know themselves.

  7. Study of the Reflex-Klystron

    International Nuclear Information System (INIS)

    Valencia A, R.

    1981-01-01

    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. Physiological responses to hypothermia.

    Science.gov (United States)

    Wood, Thomas; Thoresen, Marianne

    2015-04-01

    Therapeutic hypothermia is the only treatment currently recommended for moderate or severe encephalopathy of hypoxic‒ischaemic origin in term neonates. Though the effects of hypothermia on human physiology have been explored for many decades, much of the data comes from animal or adult studies; the latter originally after accidental hypothermia, followed by application of controlled hypothermia after cardiac arrest or trauma, or during cardiopulmonary bypass. Though this work is informative, the effects of hypothermia on neonatal physiology after perinatal asphyxia must be considered in the context of a prolonged hypoxic insult that has already induced a number of significant physiological sequelae. This article reviews the effects of therapeutic hypothermia on respiratory, cardiovascular, and metabolic parameters, including glycaemic control and feeding requirements. The potential pitfalls of blood‒gas analysis and overtreatment of physiological changes in cardiovascular parameters are also discussed. Finally, the effects of hypothermia on drug metabolism are covered, focusing on how the pharmacokinetics, pharmacodynamics, and dosing requirements of drugs frequently used in neonatal intensive care may change during therapeutic hypothermia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Assessment of operators' mental workload using physiological and subjective measures in cement, city traffic and power plant control centers.

    Science.gov (United States)

    Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

    2016-01-01

    The present study aimed to evaluate the operators' mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. The results suggested that when operators' mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions.

  10. Assessment of operators’ mental workload using physiological and subjective measures in cement, city traffic and power plant control centers

    Science.gov (United States)

    Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

    2016-01-01

    Background: The present study aimed to evaluate the operators’ mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. Methods: This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. Results: The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. Conclusion: The results suggested that when operators’ mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions. PMID:27386425

  11. Space Physiology within an Exercise Physiology Curriculum

    Science.gov (United States)

    Carter, Jason R.; West, John B.

    2013-01-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

  12. A systems biology approach to studying Tai Chi, physiological complexity and healthy aging: design and rationale of a pragmatic randomized controlled trial.

    Science.gov (United States)

    Wayne, Peter M; Manor, Brad; Novak, Vera; Costa, Madelena D; Hausdorff, Jeffrey M; Goldberger, Ary L; Ahn, Andrew C; Yeh, Gloria Y; Peng, C-K; Lough, Matthew; Davis, Roger B; Quilty, Mary T; Lipsitz, Lewis A

    2013-01-01

    Aging is typically associated with progressive multi-system impairment that leads to decreased physical and cognitive function and reduced adaptability to stress. Due to its capacity to characterize complex dynamics within and between physiological systems, the emerging field of complex systems biology and its array of quantitative tools show great promise for improving our understanding of aging, monitoring senescence, and providing biomarkers for evaluating novel interventions, including promising mind-body exercises, that treat age-related disease and promote healthy aging. An ongoing, two-arm randomized clinical trial is evaluating the potential of Tai Chi mind-body exercise to attenuate age-related loss of complexity. A total of 60 Tai Chi-naïve healthy older adults (aged 50-79) are being randomized to either six months of Tai Chi training (n=30), or to a waitlist control receiving unaltered usual medical care (n=30). Our primary outcomes are complexity-based measures of heart rate, standing postural sway and gait stride interval dynamics assessed at 3 and 6months. Multiscale entropy and detrended fluctuation analysis are used as entropy- and fractal-based measures of complexity, respectively. Secondary outcomes include measures of physical and psychological function and tests of physiological adaptability also assessed at 3 and 6months. Results of this study may lead to novel biomarkers that help us monitor and understand the physiological processes of aging and explore the potential benefits of Tai Chi and related mind-body exercises for healthy aging. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. 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.

    2017-12-01

    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.

  14. Quantitative rest activity in ambulatory monitoring as a physiological marker of restless legs syndrome: a controlled study.

    Science.gov (United States)

    Tuisku, Katinka; Holi, Matti Mikael; Wahlbeck, Kristian; Ahlgren, Aulikki Johanna; Lauerma, Hannu

    2003-04-01

    An objective marker of restless legs syndrome (RLS) is needed for developing diagnostic tools and monitoring symptoms. Actometric ambulatory monitoring of 15 RLS patients and 15 healthy controls was undertaken in order to differentiate between RLS-related motor symptoms and normal motor activity. Nocturnal lower-limb activity per minute differentiated and discriminated between groups with no overlap, whereas the periodic limb movement index and the controlled rest activity during sitting showed less discriminative power. The naturalistic recording of nocturnal activity by actometry may prove useful for assessing the severity of RLS and for finding an objective marker to support the diagnosis of RLS. Copyright 2002 Movement Disorder Society

  15. Aerospace physiology.

    Science.gov (United States)

    2004-01-01

    This document defines the protocol standards for the Internet Protocol Suite (IPS), which is commonly referred to as Transmission Control Protocol/Internet Protocol (TCP/IP) protocols used for data communications within the National Airspace System (...

  16. Increased auditory startle reflex in children with functional abdominal pain.

    Science.gov (United States)

    Bakker, Mirte J; Boer, Frits; Benninga, Marc A; Koelman, Johannes H T M; Tijssen, Marina A J

    2010-02-01

    To test the hypothesis that children with abdominal pain-related functional gastrointestinal disorders have a general hypersensitivity for sensory stimuli. Auditory startle reflexes were assessed in 20 children classified according to Rome III classifications of abdominal pain-related functional gastrointestinal disorders (13 irritable bowel syndrome [IBS], 7 functional abdominal pain syndrome; mean age, 12.4 years; 15 girls) and 23 control subjects (14 girls; mean age, 12.3 years) using a case-control design. The activity of 6 left-sided muscles and the sympathetic skin response were obtained by an electromyogram. We presented sudden loud noises to the subjects through headphones. Both the combined response of 6 muscles and the blink response proved to be significantly increased in patients with abdominal pain compared with control subjects. A significant increase of the sympathetic skin response was not found. Comorbid anxiety disorders (8 patients with abdominal pain) or Rome III subclassification did not significantly affect these results. This study demonstrates an objective hyperresponsivity to nongastrointestinal stimuli. Children with abdominal pain-related functional gastrointestinal disorders may have a generalized hypersensitivity of the central nervous system. Copyright 2010 Mosby, Inc. All rights reserved.

  17. Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex

    Directory of Open Access Journals (Sweden)

    Karl Yngvar Dale

    2008-06-01

    Full Text Available Karl Yngvar Dale1, Magne Arve Flaten1, Åke Elden1, Arne Holte21Department of Psychology, University of Tromsø, Norway; 2The Norwegian Institute of Public Health, Department of Mental Health, Oslo, Norway and University of Oslo, NorwayAbstract: 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.Keywords: dissociation, DID, PPI, startle, habituation

  18. Training induced adaptations in characteristics of postural reflexes in elderly men.

    Science.gov (United States)

    Granacher, U; Gollhofer, A; Strass, D

    2006-12-01

    The aging neuromuscular system is affected by structural and functional changes which lead to a general slowing down of neuromuscular performance and an increased risk of falling. The impact of heavy resistance (HR) training in the elderly on maximum voluntary contraction (MVC) and rate of force development (RFD) has been investigated in the past. However, the influence of sensorimotor (SENSO) training and HR training on the ability to compensate for gait perturbations has not yet been investigated in the elderly. Therefore, the purpose of the study was to examine the impact of HR and SENSO training in elderly men on unexpected treadmill perturbations. Functional reflex activity was recorded by means of surface EMG in 40 male subjects (>60 years) before and after 13 weeks of HR and SENSO training and in another 20 male subjects (>60 years), which served as a CONTROL-group. SENSO training resulted in a decrease in onset latency, an enhanced reflex activity in the prime mover as well as a decrease in maximal angular velocity of the ankle joint complex during the perturbation impulses. No significant changes were observed in the HR- and in the CONTROL-group. The results clearly indicate that SENSO training has an impact on spinal motor control mechanisms in the elderly. Training induced improvements in perception and procession of afferent information could be a possible reason for the increase in reflex contraction. Due to these adaptive processes, SENSO training could be a well-suited method for fall preventive programs in elderly people.

  19. Application of Physiological Self-Regulation and Adaptive Task Allocation Techniques for Controlling Operator Hazardous States of Awareness

    Science.gov (United States)

    Prinzel, Lawrence J., III; Pope, Alan T.; Freeman, Frederick G.

    2001-01-01

    Prinzel, Hadley, Freeman, and Mikulka found that adaptive task allocation significantly enhanced performance only when used at the endpoints of the task workload continuum (i.e., very low or high workload), but that the technique degraded performance if invoked during other levels of task demand. These researchers suggested that other techniques should be used in conjunction with adaptive automation to help minimize the onset of hazardous states of awareness (HSA) and keep the operator 'in-the-loop.' The paper reports on such a technique that uses psychophysiological self-regulation to modulate the level of task engagement. Eighteen participants were assigned to three groups (self-regulation, false feedback, and control) and performed a compensatory tracking task that was cycled between three levels of task difficulty on the basis of the electroencephalogram (EEG) record. Those participants who had received self-regulation training performed significantly better and reported lower NASA-TLX scores than participants in the false feedback and control groups. Furthermore, the false feedback and control groups had significantly more task allocations resulting in return-to-manual performance decrements and higher EEG difference scores. Theoretical and practical implications of these results for adaptive automation are discussed.

  20. The endocannabinoid anandamide regulates the peristaltic reflex by reducing neuro-neuronal and neuro-muscular neurotransmission in ascending myenteric reflex pathways in rats.

    Science.gov (United States)

    Sibaev, Andrei; Yuece, Birol; Allescher, Hans Dieter; Saur, Dieter; Storr, Martin; Kurjak, Manfred

    2014-04-01

    Endocannabinoids (EC) and the cannabinoid-1 (CB1) receptor are involved in the regulation of motility in the gastrointestinal (GI) tract. However, the underlying physiological mechanisms are not completely resolved. The purpose of this work was to study the physiological influence of the endocannabinoid anandamide, the putative endogenous CB1 active cannabinoid, and of the CB1 receptor on ascending peristaltic activity and to identify the involved neuro-neuronal, neuro-muscular and electrophysiological mechanisms. The effects of anandamide and the CB1 receptor antagonist SR141716A were investigated on contractions of the circular smooth muscle of rat ileum and in longitudinal rat ileum segments where the ascending myenteric part of the peristaltic reflex was studied in a newly designed organ bath. Additionally intracellular recordings were performed in ileum and colon. Anandamide significantly reduced cholinergic twitch contractions of ileum smooth muscle whereas SR141716A caused an increase. Anandamide reduced the ascending peristaltic contraction by affecting neuro-neuronal and neuro-muscular neurotransmission. SR141716A showed opposite effects and all anandamide effects were antagonized by SR141716A (1 μM). Anandamide reduced excitatory junction potentials (EJP) and inhibitory junction potentials (IJP), whereas intestinal slow waves were not affected. CB1 receptors regulate force and timing of the intestinal peristaltic reflex and these actions involve interneurons and motor-neurons. The endogenous cannabinoid anandamide mediates these effects by activation of CB1 receptors. The endogenous cannabinoid system is permanently active, suggesting the CB1 receptor being a possible target for the treatment of motility related disorders. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. Randomized controlled trial of skin-to-skin contact from birth versus conventional incubator for physiological stabilization in 1200- to 2199-gram newborns.

    Science.gov (United States)

    Bergman, N J; Linley, L L; Fawcus, S R

    2004-06-01

    Conventional care of prematurely born infants involves extended maternal-infant separation and incubator care. Recent research has shown that separation causes adverse effects. Maternal-infant skin-to-skin contact (SSC) provides an alternative habitat to the incubator, with proven benefits for stable prematures; this has not been established for unstable or newborn low-birthweight infants. SSC from birth was therefore compared to incubator care for infants between 1200 and 2199 g at birth. This was a prospective, unblinded, randomized controlled clinical trial; potential subjects were identified before delivery and randomized by computerized minimization technique at 5 min if eligible. Standardized care and observations were maintained for 6 h. Stability was measured in terms of a set of pre-determined physiological parameters, and a composite cardio-respiratory stabilization score (SCRIP). 34 infants were analysed in comparable groups: 3/18 SSC compared to 12/13 incubator babies exceeded the pre-determined parameters (p incubator (maximum 78), mean difference 2.88 (95% CI: 0.3-5.46, p = 0.031). All 18 SSC subjects were stable in the sixth hour, compared to 6/13 incubator infants. Eight out of 13 incubator subjects experienced hypothermia. Newborn care provided by skin-to-skin contact on the mother's chest results in better physiological outcomes and stability than the same care provided in closed servo-controlled incubators. The cardio-respiratory instability seen in separated infants in the first 6 h is consistent with mammalian "protest-despair" biology, and with "hyper-arousal and dissociation" response patterns described in human infants: newborns should not be separated from their mothers.

  2. The Danish CSR Reporting Requirement as Reflexive Law

    DEFF Research Database (Denmark)

    Buhmann, Karin

    2013-01-01

    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...

  3. Increased Auditory Startle Reflex in Children with Functional Abdominal Pain

    NARCIS (Netherlands)

    Bakker, Mirte J.; Boer, Frits; Benninga, Marc A.; Koelman, Johannes H. T. M.; Tijssen, Marina A. J.

    2010-01-01

    Objective To test the hypothesis that children with abdominal pain-related functional gastrointestinal disorders have a general hypersensitivity for sensory stimuli. Study design Auditory startle reflexes were assessed in 20 children classified according to Rome III classifications of abdominal

  4. Increased Auditory Startle Reflex in Children with Functional Abdominal Pain

    NARCIS (Netherlands)

    Bakker, Mirte J.; Boer, Frits; Benninga, Marc A.; Koelman, Johannes H. T. M.; Tijssen, Marina A. J.

    Objective To test the hypothesis that children with abdominal pain-related functional gastrointestinal disorders have a general hypersensitivity for sensory stimuli. Study design Auditory startle reflexes were assessed in 20 children classified according to Rome III classifications of abdominal

  5. Learning of conditioned reflexes of the Wistar rat under intermittent action of low CO concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Zorn, H.

    1972-04-01

    The influence of an intermittent long-time exposure to a concentration of 150 ppm carbon monoxide on the ability to learn conditioned reflexes was investigated with Wistar rats. Half the 80 rats employed and divided into intelligence groups were exposed to this concentration at night five times for 8 hr weekly. The carboxyhemoglobin level in the blood of these animals increased to 7-13 percent. After an adequate interval for CO elimination, the rats exposed and the control animals were trained to develop a conditioned flight reflex. At a later date, the results were ascertained. With regard to the progress in learning this action, the CO-exposed animals showed a significant reduction in performance (longer learning time, more frequent deficient behavior, and inclination for stupor and anxious denial).

  6. Bone mineral density in reflex sympathetic dystrophy

    International Nuclear Information System (INIS)

    Saghaphi, M.; Azarian, A.

    2002-01-01

    Objectives: Reflex Sympathetic Dystrophy (RSD) is a complex of symptoms that produce pain burning sensation, swelling, tenderness, autonomic and physical dysfunction in joint areas, particularly distal of a limb. Osteopenia or osteoporosis is an important finding that is produced gradually in involved limb. Three phase bone can scan help to diagnosis of RSD. The disease may be bilateral but is mostly unilateral. As it is believed that bone densitometry will show osteopenia more accurate than plain comparative radiographs of the involved limbs, we investigated in patients with RSD. Methods: During last three years, 8 patients with RSD were admitted. Bone mineral density was measured for 5 patients by DEXA method. The patients were 3 males and 2 females with age range of 20 to 48 years (mean 32 years). The involved areas were ankle and foot in 4, and wrist and hand in one patient. Results: Mean Bone Mineral Content (BMC) of 4 involved lower limbs were 475 +-73 grams comparing with 516+-72 grams of uninvolved limbs (p t h patient was not significant. conclusion: comparative bone mineral density in patients with RSD of the lower limbs contributes to more accurate diagnosis than plain radiographs

  7. Physiological and Histological Alterations in Rats Liver Induced by Sumithion NP 25/2.5 EC, an Insecticide Used in Dengue Fever Vector Control in Jeddah, Saudi Arabia

    International Nuclear Information System (INIS)

    AlJahdali, Mohammed O.; Bisher, Ameen S. Bin; Zeid, Isam M. Abu

    2009-01-01

    The hepatotoxicity of Sumithion NP 25/2.5 EC, a new formulated organophosphorous insecticide used in dengue fever vector (Aedes aegypti) control in Jeddah (Saudi Arabia), was studied in albino rats. Both levels of GPT, GOT and ALP, and the combined histological alterations were assessed after treatment. Rats were daily injected intraperitoneally for two and four weeks with 80 and 200 mg/kg of body weight (1/10 and 1/4 of the LD50, respectively). Significant increase in GPT, GOT and ALP levels relative to the increase of treatment dose and duration time was observed. The time factor effect was remarkably noticed in ALP level fluctuation. These results indicate a remarkable defect in the liver functions induced by Sumithion NP 25/2.5 EC. Also, histological alterations in the treated animal's liver were observed including: blood congestion, fatty degeneration, hepatocytes swelling and necrosis. The liver syndrome's intensity correlated with the increase in dose and duration time. The present results could prove the hepatotoxicity of Sumithion NP 25/2.5 EC and its ability to cause severe physiological and histopathological defects in the liver. Therefore, the chemical control of Aedes aegypti must be reduced and other recommended control strategies should be promoted. (author)

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

    Science.gov (United States)

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

    2015-11-01

    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 well as speeded 2-choice finger motor responses. Different groups of subjects were trained on a standard prosaccade gap paradigm before periods of nocturnal sleep and sleep deprivation. Saccade performance was retested in the next morning and again 24 h later. The rate of express saccades was not affected by sleep after training, but slightly increased after sleep deprivation. Surprisingly, this increase augmented even further after recovery sleep and was still present 4 weeks later. Additional experiments revealed that the short testing after sleep deprivation was sufficient to increase express saccades across recovery sleep. An increase in speeded responses across recovery sleep was likewise found for finger motor responses. Our findings indicate that recovery sleep can consolidate motor disinhibition for behaviors practiced during prior sleep deprivation, thereby persistently enhancing response automatization. © The Author 2015. Published by Oxford University Press.

  9. Reversal of reflex pulmonary vasoconstriction induced by main pulmonary arterial distension.

    Science.gov (United States)

    Juratsch, C E; Grover, R F; Rose, C E; Reeves, J T; Walby, W F; Laks, M M

    1985-04-01

    Distension of the main pulmonary artery (MPA) induces pulmonary hypertension, most probably by neurogenic reflex pulmonary vasoconstriction, although constriction of the pulmonary vessels has not actually been demonstrated. In previous studies in dogs with increased pulmonary vascular resistance produced by airway hypoxia, exogenous arachidonic acid has led to the production of pulmonary vasodilator prostaglandins. Hence, in the present study, we investigated the effect of arachidonic acid in seven intact anesthetized dogs after pulmonary vascular resistance was increased by MPA distention. After steady-state pulmonary hypertension was established, arachidonic acid (1.0 mg/min) was infused into the right ventricle for 16 min; 15-20 min later a 16-mg bolus of arachidonic acid was injected. MPA distension was maintained throughout the study. Although the infusion of arachidonic acid significantly lowered the elevated pulmonary vascular resistance induced by MPA distension, the pulmonary vascular resistance returned to control levels only after the bolus injection of arachidonic acid. Notably, the bolus injection caused a biphasic response which first increased the pulmonary vascular resistance transiently before lowering it to control levels. In dogs with resting levels of pulmonary vascular resistance, administration of arachidonic acid in the same manner did not alter the pulmonary vascular resistance. It is concluded that MPA distension does indeed cause reflex pulmonary vasoconstriction which can be reversed by vasodilator metabolites of arachidonic acid. Even though this reflex may help maintain high pulmonary vascular resistance in the fetus, its function in the adult is obscure.

  10. Effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations

    NARCIS (Netherlands)

    Renden, Peter G.; Savelsbergh, Geert J. P.; Oudejans, Raoul R. D.

    2017-01-01

    We investigated the effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations. Police officers received this training as well as a regular police arrest and self-defence skills training (control training) in a crossover design. Officers’

  11. A tapetal-like fundus reflex in a healthy male

    DEFF Research Database (Denmark)

    Schatz, Patrik; Bregnhøj, Jesper; Arvidsson, Henrik

    2012-01-01

    To report on the retinal function and structure in a 37-year-old male who presented with a tapetal-like reflex (TLR) indistinguishable from that seen in female carriers of X-linked retinitis pigmentosa (XLRP).......To report on the retinal function and structure in a 37-year-old male who presented with a tapetal-like reflex (TLR) indistinguishable from that seen in female carriers of X-linked retinitis pigmentosa (XLRP)....

  12. The Reflexive Nature of Reading as Ethnographic Practice: Editorial Note

    Directory of Open Access Journals (Sweden)

    Wolff-Michael Roth

    2004-01-01

    Full Text Available In this editorial, I suggest that not only is reading published texts a way of doing ethno­graph­ic research, but also reading concretely realizes itself in the productions of new texts that reproduce the cultural practices that are analyzed in the published text. Reading as ethnographic method is therefore a reflexive project. I provide a dialectical framework for theorizing the reflexive nature of reading. URN: urn:nbn:de:0114-fqs0401390

  13. The psychology and physiology of temperament: pragmatism in context.

    Science.gov (United States)

    Bordogna, F

    2001-01-01

    This paper traces William James's famous "temperament thesis" according to which the philosophical stance that individuals take depends on their "temperaments." It seeks to understand James's conception of temperament by locating James within a set of contemporary investigations that linked the sources of mental, and even higher, intellectual processes to the physiological and organic constitution of the individual. The paper argues that James understood temperament along the reflex-arc model and discusses the implications of that physiological account of temperament for James's overall conception of philosophy.

  14. 'Scarlett Spur Red Delicious' apple volatile production accompanying physiological disorder development during low pO2 controlled atmosphere storage.

    Science.gov (United States)

    Lumpkin, Christie; Fellman, John K; Rudell, David R; Mattheis, James

    2014-02-19

    Apple (Malus domestica Borkh.) fruit volatile production is regulated by a variety of factors including low oxygen storage conditions. This study examined the impact of low pO2 controlled atmospheres on 'Scarlett Spur Red Delicious' apple volatile production and disorder development. Accumulation of apple volatile compounds was characterized during long-term cold storage at 0.5 °C in air or low pO2 (0.3, 0.8, or 1.5 kPa) with 1 kPa CO2. Volatile accumulation differed quantitatively with pO2 as acetaldehyde, ethanol, and ethyl ester accumulation increased with decreased pO2 during the first weeks in storage. Differences in volatile accumulation among atmospheres were evident through 6 months. The rate of ethanol accumulation increased with decreased pO2 and could potentially be used to monitor low O2 stress. Incidence of low oxygen disorders after 9 months was highest in fruit held at the lowest pO2. The sesquiterpene α-farnesene was not detected throughout the storage period.

  15. Evaluation of diverse wheat genotypes for potential biomass production through physiological parameters at seedling stage under controlled environment

    International Nuclear Information System (INIS)

    Khattak, G.S.S.

    2014-01-01

    Thirty wheat genotypes from UK, CIMMYT and Pakistan were evaluated under controlled environment conditions for their potential biomass production by measuring stomatal conductance (gs; porometry), leaf photosynthesis (IRGA), carbon isotope discrimination and carbon content (isotope ratio and mass analysis) at Rothamsted Research, Harpenden, UK during 2011. Amongst the dwarf genotypes, Rht2 and Rht3 showed lower stomatal conductance than Seri 32B, Seri 87B and Bathoor-07. For these 5 genotypes and another genotype Inqalab photosynthetic performance was determined by means of IRGA measurements. Of these genotypes Inqalab had the highest photosynthetic activity (A), stomatal conductance (gs), transpiration (E) and leaf intercellular CO/sub 2/ but it also had the lowest water use efficiency (A/gs) and intrinsic water use efficiency (A/E). Seri-87B had the greatest water use efficiency (A/gs) and intrinsic water use efficiency (A/E). All the Pakistani genotypes had large stomatal conductances and high 13C delta and thus may be expected to produce high biomass under irrigations and optimum inputs. (author)

  16. Intact reflexive but deficient voluntary social orienting in autism spectrum disorder

    Directory of Open Access Journals (Sweden)

    Megan Anne Kirchgessner

    2015-12-01

    Full Text Available Impairment in social interactions is a primary characteristic of people diagnosed with autism spectrum disorder (ASD. Although these individuals tend to orient less to naturalistic social cues than do typically developing (TD individuals, laboratory experiments testing social orienting in ASD have been inconclusive, possibly because of a failure to fully isolate reflexive (stimulus-driven and voluntary (goal-directed social orienting processes. The purpose of the present study was to separately examine potential reflexive and/or voluntary social orienting differences in individuals with ASD relative to TD controls. Subjects (ages 7-14 with high-functioning ASD and a matched control group completed three gaze cueing tasks on an iPad in which individuals briefly saw a face with averted gaze followed by a target after a variable delay. Two tasks were 100% predictive with either all congruent (target appears in gaze direction or all incongruent (target appears opposite from gaze direction trials, respectively. Another task was non-predictive with these same trials (half congruent and half incongruent intermixed randomly. Response times (RTs to the target were used to calculate reflexive (incongruent condition RT – congruent condition RT and voluntary (non-predictive condition RT – predictive condition RT gaze cueing effects. Subjects also completed two additional non-social orienting tasks (ProPoint and AntiPoint. Subjects with ASD demonstrate intact reflexive but deficient voluntary gaze following. Similar results were found in a separate test of non-social orienting. This suggests problems with using social cues, but only in a goal-directed fashion, in our sample of high-functioning individuals with ASD. Such findings may not only explain inconclusive previous findings but more importantly be critical for understanding social dysfunctions in ASD and for developing future interventions.

  17. Anticausatives are weak scalar expressions, not reflexive expressions

    Directory of Open Access Journals (Sweden)

    Florian Schäfer

    2016-07-01

    Full Text Available We discuss conceptual and empirical arguments from Germanic, Romance and Slavic languages against an analysis treating anticausative verbs as derived from their lexical causative counterparts under reflexivization. Instead, we defend the standard account to the semantics of the causative alternation according to which anticausatives in general, and anticausatives marked with reflexive morphology in particular, denote simple one-place inchoative events that are logically entailed by their lexical causative counterparts. Under such an account, anticausative verbs are weak scalar expressions that stand in a semantico-pragmatic opposition to their strong lexical causative counterparts. Due to this scalar relation, the use of an anticausative can trigger the implicature that the use of its lexical causative counterpart is too strong. As usual with implicatures, they can be ‘metalinguistically’ denied, cancelled, or reinforced and we argue that these mechanisms explain all central empirical facts brought up in the literature in favor of a treatment of anticausatives as semantically reflexive predicates. Our results reinforce the view that the reflexive morphemes used in many (Indo-European languages to mark anticausatives do not necessarily trigger reflexive semantics. However, we also show that a string involving a reflexively marked (anti-causative verb can be forced into a semantically reflexive construal under particular conceptual or grammatical circumstances.

  18. Trigeminocardiac reflex during endoscopic juvenile nasopharyngeal angiofibroma surgery: an appraisal.

    Science.gov (United States)

    Sharma, Shilpee Bhatia; Janakiram, Trichy Narayanan; Baxi, Hina; Chinnasamy, Balamurugan

    2017-07-01

    Juvenile nasopharyngeal angiofibroma is a locally aggressive benign tumour which has propensity to erode the skull base. The tumour spreads along the pathways of least resistance and is in close proximity to the extracranial part of trigeminal nerve. Advancements in expanded approaches for endoscopic excision of tumours in infratemporal fossa and pterygopalatine fossa increase the vulnerability for the trigeminocardiac reflex. The manipulation of nerve and its branches during tumour dissection can lead to sensory stimulation and thus inciting the reflex. The aim of our study is to report the occurrence of trigeminocardiac reflex in endoscopic excision of juvenile nasopharyngeal angiofibroma. To describe the occurence of trigeminocardiac reflex during endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma. We studied the occurrence of TCR in 15 patients (out of 242 primary cases and 52 revision cases) operated for endoscopic endonasal excision of JNA. The drop in mean arterial blood pressure and heart rate were observed and measured. To the best of our knowledge of English literature, this is the first case series reporting TCR as complication in endoscopic excision of JNA. occurence of this reflex has been mentioned in various occular, maxillofacial surgeries but its occurence during endoscopic excision of JNA has never been reported before. Manifestation of trigeminocardiac reflex during surgery can alter the course of the surgery and is a potential threat to life. It is essential for the anesthetist and surgeons to be familiar with the presentations, preventive measures and management protocols.

  19. Avian reflex and electroencephalogram responses in different states of consciousness.

    Science.gov (United States)

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

    2014-06-22

    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.

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

    Directory of Open Access Journals (Sweden)

    Tea Golob

    2018-03-01

    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.

  1. A method of reflexive balancing in a pragmatic, interdisciplinary and reflexive bioethics.

    Science.gov (United States)

    Ives, Jonathan

    2014-07-01

    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.

  2. Gain modulation of the middle latency cutaneous reflex in patients with chronic joint instability after ankle sprain.

    Science.gov (United States)

    Futatsubashi, Genki; Sasada, Shusaku; Tazoe, Toshiki; Komiyama, Tomoyoshi

    2013-07-01

    To investigate the neural alteration of reflex pathways arising from cutaneous afferents in patients with chronic ankle instability. Cutaneous reflexes were elicited by applying non-noxious electrical stimulation to the sural nerve of subjects with chronic ankle instability (n=17) and control subjects (n=17) while sitting. Electromyographic (EMG) signals were recorded from each ankle and thigh muscle. The middle latency response (MLR; latency: 70-120 ms) component was analyzed. In the peroneus longus (PL) and vastus lateralis (VL) muscles, linear regression analyses between the magnitude of the inhibitory MLR and background EMG activity showed that, compared to the uninjured side and the control subjects, the gain of the suppressive MLR was increased in the injured side. This was also confirmed by the pooled data for both groups. The degree of MLR alteration was significantly correlated to that of chronic ankle instability in the PL. The excitability of middle latency cutaneous reflexes in the PL and VL is modulated in subjects with chronic ankle instability. Cutaneous reflexes may be potential tools to investigate the pathological state of the neural system that controls the lower limbs in subjects with chronic ankle instability. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Controlled atmosphere stunning of broiler chickens. I. Effects on behaviour, physiology and meat quality in a pilot scale system at a processing plant.

    Science.gov (United States)

    Abeyesinghe, S M; McKeegan, D E F; McLeman, M A; Lowe, J C; Demmers, T G M; White, R P; Kranen, R W; van Bemmel, H; Lankhaar, J A C; Wathes, C M

    2007-08-01

    1. The effects of controlled atmosphere stunning on the behaviour, physiology and carcase and meat quality of broiler chickens were studied experimentally in a pilot scale plant. 2. Gas mixtures tested were: single phase anoxic mixture (90% Ar in air, posture occurred soonest with hypercapnic anoxia with the earliest and most twitching and wing flapping in individuals and earliest leg paddling. Biphasic birds were most alert, exhibited most respiratory disruption and mandibulation, and had the latest loss of posture and fewest, but longest bouts of wing flapping and least leg paddling and twitching. 4. Significant and sudden bradycardia and arrhythmia were evident with all gas mixtures and were not related solely to anoxia or hypercapnia. Birds stunned by Ar anoxia showed a slightly more gradual decline from baseline rates, compared with hypercapnic mixtures. 5. Few differences were found between gas mixes in terms of carcase and meat quality. Initial bleeding rate was slowest in biphasic-stunned birds, but total blood loss was not affected. Acceleration of post-mortem metabolism in anoxic-stunned birds was not sufficient to allow de-boning within 5 h without the risk of tough meat. 6. On welfare grounds and taking into account other laboratory and field studies, a biphasic method (using consecutive phases of anaesthesia and euthanasia) of controlled atmosphere stunning of broilers is potentially more humane than anoxic or hypercapnic anoxic methods using argon or nitrogen.

  4. Effect of a novel two-desk sit-to-stand workplace (ACTIVE OFFICE on sitting time, performance and physiological parameters: protocol for a randomized control trial

    Directory of Open Access Journals (Sweden)

    Bernhard Schwartz

    2016-07-01

    Full Text Available Abstract Background Prolonged sitting is ubiquitous in modern society and linked to several diseases. Height-adjustable desks are being used to decrease worksite based sitting time (ST. Single-desk sit-to-stand workplaces exhibit small ST reduction potential and short-term loss in performance. The aim of this paper is to report the study design and methodology of an ACTIVE OFFICE trial. Design The study was a 1-year three-arm, randomized controlled trial in 18 healthy Austrian office workers. Allocation was done via a regional health insurance, with data collection during Jan 2014 – March 2015. Participants were allocated to either an intervention or control group. Intervention group subjects were provided with traditional or two-desk sit-to-stand workstations in either the first or the second half of the study, while control subjects did not experience any changes during the whole study duration. Sitting time and physical activity (IPAQ-long, cognitive performance (text editing task, Stroop-test, d2R test of attention, workload perception (NASA-TLX and physiological parameters (salivary cortisol, heartrate variability and body weight were measured pre- and post-intervention (23 weeks after baseline for intervention and control periods. Postural changes and sitting/standing time (software logger were recorded at the workplace for the whole intervention period. Discussion This study evaluates the effects of a novel two-desk sit-to-stand workplace on sitting time, physical parameters and work performance of healthy office based workers. If the intervention proves effective, it has a great potential to be implemented in regular workplaces to reduce diseases related to prolonged sitting. Trial registration ClinicalTrials.gov Identifier: NCT02825303 , July 2016 (retrospectively registered.

  5. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

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

    1997-01-01

    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

  6. GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

    Directory of Open Access Journals (Sweden)

    Lei Ding

    Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

  7. Baroreflex and neurovascular responses to skeletal muscle mechanoreflex activation in humans: an exercise in integrative physiology.

    Science.gov (United States)

    Drew, Rachel C

    2017-12-01

    Cardiovascular adjustments to exercise resulting in increased blood pressure (BP) and heart rate (HR) occur in response to activation of several neural mechanisms: the exercise pressor reflex, central command, and the arterial baroreflex. Neural inputs from these feedback and feedforward mechanisms integrate in the cardiovascular control centers in the brain stem and modulate sympathetic and parasympathetic neural outflow, resulting in the increased BP and HR observed during exercise. Another specific consequence of the central neural integration of these inputs during exercise is increased sympathetic neural outflow directed to the kidneys, causing renal vasoconstriction, a key reflex mechanism involved in blood flow redistribution during increased skeletal muscle work. Studies in humans have shown that muscle mechanoreflex activation inhibits cardiac vagal outflow, decreasing the sensitivity of baroreflex control of HR. Metabolite sensitization of muscle mechanoreceptors can lead to reduced sensitivity of baroreflex control of HR, with thromboxane being one of the metabolites involved, via greater inhibition of cardiac vagal outflow without affecting baroreflex control of BP or baroreflex resetting. Muscle mechanoreflex activation appears to play a predominant role in causing renal vasoconstriction, both in isolation and in the presence of local metabolites. Limited investigations in older adults and patients with cardiovascular-related disease have provided some insight into how the influence of muscle mechanoreflex activation on baroreflex function and renal vasoconstriction is altered in these populations. However, future research is warranted to better elucidate the specific effect of muscle mechanoreflex activation on baroreflex and neurovascular responses with aging and cardiovascular-related disease. Copyright © 2017 the American Physiological Society.

  8. The Politics of Reflexive Governance: Challenges for Designing Adaptive Management and Transition Management

    Directory of Open Access Journals (Sweden)

    Jan-Peter Voß

    2011-06-01

    Full Text Available New concepts of governance take account of ambivalence, uncertainty, and distributed power in societal change. They aim for reflexivity regarding the limits of prognostic knowledge and actual control of complex processes of change. Adaptive management and transition management are two examples that evolved from the analysis of social-ecological and sociotechnical systems, respectively. Both feature strategies of collective experimentation and learning. In this paper, we ask how these two designs of reflexive governance consider politics. Based on a framework of different dimensions and levels of politics, we show that they are mainly concerned with problem solving by a focal process, but conflict and asymmetric power relations, as well as the embedding of processes within broader political contexts, are neglected. We suggest two routes for integrating politics into the design of reflexive governance: (1 recognize the politics of learning for sustainable development and develop safeguards against domination and capture by powerful actors, and (2 systematically consider the embedding of governance designs in political contexts and their ongoing dynamics for political fit.

  9. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping

    Directory of Open Access Journals (Sweden)

    Christian Schumacher

    2017-11-01

    Full Text Available In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB, velocity (VFB and force feedback (FFB pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort. Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map. The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency. Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length or environmental parameters (ground compliance. Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a

  10. Altered Neuromodulatory Drive May Contribute to Exaggerated Tonic Vibration Reflexes in Chronic Hemiparetic Stroke

    Directory of Open Access Journals (Sweden)

    Jacob G. McPherson

    2018-04-01

    Full Text Available Exaggerated stretch-sensitive reflexes are a common finding in elbow flexors of the contralesional arm in chronic hemiparetic stroke, particularly when muscles are not voluntarily activated prior to stretch. Previous investigations have suggested that this exaggeration could arise either from an abnormal tonic ionotropic drive to motoneuron pools innervating the paretic limbs, which could bring additional motor units near firing threshold, or from an increased influence of descending monoaminergic neuromodulatory pathways, which could depolarize motoneurons and amplify their responses to synaptic inputs. However, previous investigations have been unable to differentiate between these explanations, leaving the source(s of this excitability increase unclear. Here, we used tonic vibration reflexes (TVRs during voluntary muscle contractions of increasing magnitude to infer the sources of spinal motor excitability in individuals with chronic hemiparetic stroke. We show that when the paretic and non-paretic elbow flexors are preactivated to the same percentage of maximum prior to vibration, TVRs remain significantly elevated in the paretic arm. We also show that the rate of vibration-induced torque development increases as a function of increasing preactivation in the paretic limb, even though the amplitude of vibration-induced torque remains conspicuously unchanged as preactivation increases. It is highly unlikely that these findings could be explained by a source that is either purely ionotropic or purely neuromodulatory, because matching preactivation should control for the effects of a potential ionotropic drive (and lead to comparable tonic vibration reflex responses between limbs, while a purely monoaminergic mechanism would increase reflex magnitude as a function of preactivation. Thus, our results suggest that increased excitability of motor pools innervating the paretic limb post-stroke is likely to arise from both ionotropic and

  11. Local Injections of Superoxide Dismutase Attenuate the Exercise Pressor Reflex in Rats with Femoral Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Jihong Xing

    2018-02-01

    Full Text Available The exercise pressor reflex is amplified in patients with peripheral artery disease (PAD and in an experimental PAD model of rats induced by femoral artery occlusion. Heightened blood pressure worsens the restricted blood flow directed to the limbs in this disease. The purpose of this study was to determine the role played by muscle oxidative stress in regulating the augmented pressor response to static exercise in PAD. We hypothesized that limb ischemia impairs muscle superoxide dismutase (SOD thereby leading to abnormal autonomic responsiveness observed in PAD animals, and a chronic compensation of SOD for anti-oxidation improves the exaggerated exercise pressor reflex. Our data show that femoral occlusion decreased the protein levels of SOD in ischemic muscle as compared with control muscle. Downregulation of SOD appeared to a greater degree in the oxidative (red muscle than in the glycolytic (white muscle under the condition of muscle ischemia. In addition, the exercise pressor response was assessed during electrically induced static contraction. The data demonstrates that the enhancement of the exercise pressor reflex was significantly attenuated after tempol (a mimetic of SOD, 30 mg over a period of 72 h was administered into the occluded hindlimb. In the occluded rats, mean arterial pressure (MAP response was 26 ± 3 mmHg with no tempol and 12 ± 2 mmHg with tempol application (P < 0.05 vs. group with no tempol; n = 6 in each group. There were no differences in muscle tension development (time-tension index: 12.1 ± 1.2 kgs with no tempol and 13.5 ± 1.1 kgs with tempol; P > 0.05 between groups. In conclusion, SOD is lessened in the ischemic muscles and supplement of SOD improves the amplified exercise pressor reflex, which is likely beneficial to the restricted blood flow to the limbs in PAD.

  12. Trigeminal cardiac reflex and cerebral blood flow regulation

    Directory of Open Access Journals (Sweden)

    Dominga Lapi

    2016-10-01

    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.

  13. Differential physiological responses of dalmatian toadflax, Linaria dalmatica L. Miller, to injury from two insect biological control agents: Implications for decision-making in biological control

    Science.gov (United States)

    Robert K. D. Peterson; Sharlene E. Sing; David K. Weaver

    2005-01-01

    Successful biological control of invasive weeds with specialist herbivorous insects is predicated on the assumption that the injury stresses the weeds sufficiently to cause reductions in individual fitness. Because plant gas exchange directly impacts growth and fitness, characterizing how injury affects these primary processes may provide a key indicator of...

  14. Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Jageman, Robert J

    2009-09-12

    Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by

  15. Deficits in Lower Limb Muscle Reflex Contraction Latency and Peak Force Are Associated With Impairments in Postural Control and Gross Motor Skills of Children With Developmental Coordination Disorder: A Cross-Sectional Study.

    Science.gov (United States)

    Fong, Shirley S M; Ng, Shamay S M; Guo, X; Wang, Yuling; Chung, Raymond C K; Stat, Grad; Ki, W Y; Macfarlane, Duncan J

    2015-10-01

    This cross-sectional, exploratory study aimed to compare neuromuscular performance, balance and motor skills proficiencies of typically developing children and those with developmental coordination disorder (DCD) and to determine associations of these neuromuscular factors with balance and motor skills performances in children with DCD.One hundred thirty children with DCD and 117 typically developing children participated in the study. Medial hamstring and gastrocnemius muscle activation onset latencies in response to an unexpected posterior-to-anterior trunk perturbation were assessed by electromyography and accelerometer. Hamstring and gastrocnemius muscle peak force and time to peak force were quantified by dynamometer, and balance and motor skills performances were evaluated with the Movement Assessment Battery for Children (MABC).Independent t tests revealed that children with DCD had longer hamstring and gastrocnemius muscle activation onset latencies (P  0.025), than the controls. Multiple regression analysis accounting for basic demographics showed that gastrocnemius peak force was independently associated with the MABC balance subscore and ball skills subscore, accounting for 5.7% (P = 0.003) and 8.5% (P = 0.001) of the variance, respectively. Gastrocnemius muscle activation onset latency also explained 11.4% (P skills subscore.Children with DCD had delayed leg muscle activation onset times and lower isometric peak forces. Gastrocnemius peak force was associated with balance and ball skills performances, whereas timing of gastrocnemius muscle activation was a determinant of ball skill performance in the DCD population.

  16. Plantar flexor stretch reflex responses to whole body loading/unloading during human walking

    DEFF Research Database (Denmark)

    Grey, Michael James; van Doornik, Johannes; Sinkjær, Thomas

    2002-01-01

    Numerous animal and human studies have shown that afferent information from the periphery contributes to the control of walking. In particular, recent studies have consistently shown that load receptor input is an important element of the locomotion control mechanism. The objective of this study...... perturbation during human walking. Three body load conditions were investigated: normal body load, a 30% increase in body load, and a 30% decrease in body load. Healthy subjects walked on a treadmill at approximately 3.6 km/h with the left ankle attached to a portable stretching device. Dorsiflexion...... strongly to the corrective response of the stretch reflex in the plantar flexor muscles during walking....

  17. Linear time delay methods and stability analyses of the human spine. Effects of neuromuscular reflex response.

    Science.gov (United States)

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

    2008-08-01

    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.

  18. Love-hate for man-machine metaphors in Soviet physiology: from Pavlov to "physiological cybernetics".

    Science.gov (United States)

    Gerovitch, Slava

    2002-06-01

    This article reinterprets the debate between orthodox followers of the Pavlovian reflex theory and Soviet "cybernetic physiologists" in the 1950s and 60s as a clash of opposing man-machine metaphors. While both sides accused each other of "mechanistic," reductionist methodology, they did not see anything "mechanistic" about their own central metaphors: the telephone switchboard metaphor for nervous activity (the Pavlovians), and the analogies between the human brain and a computer (the cyberneticians). I argue that the scientific utility of machine analogies was closely intertwined with their philosophical and political meanings and that new interpretations of these metaphors emerged as a result of political conflicts and a realignment of forces within the scientific community and in society at large. I suggest that the constant travel of man-machine analogies, back and forth between physiology and technology has blurred the traditional categories of the "mechanistic" and the "organic" in Soviet neurophysiology, as perhaps in the history of physiology in general.

  19. A curious fact: Photic sneeze reflex. Autosomical dominant compelling helio-ophthalmic outburst syndrome.

    Science.gov (United States)

    Sevillano, C; Parafita-Fernández, A; Rodriguez-Lopez, V; Sampil, M; Moraña, N; Viso, E; Cores, F J

    2016-07-01

    To assess ocular involvement in the pathophysiology of autosomal dominant compelling helio-ophthalmic outburst syndrome (ACHOOs). An interview was conducted with a Caucasian family that showed clinical features of ACHOOs. Twelve of them had photic reflex and were recruited. A complete eye evaluation was made. A dominant autosomal inheritance with mild penetrance was demonstrated, with 67% of the studied subjects showing some degree of prominent corneal nerves. No other eye changes were found. Prominent corneal nerves may be associated with ACHOOs. The other eye structures studied do not seem to play a role in ACHOOs. Further studies are needed to understand the physiology of the ACHOOs. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  20. Nociceptive flexion reflexes during analgesic neurostimulation in man.

    Science.gov (United States)

    García-Larrea, L; Sindou, M; Mauguière, F

    1989-11-01

    Nociceptive flexion reflexes of the lower limbs (RIII responses) have been studied in 21 patients undergoing either epidural (DCS, n = 16) or transcutaneous (TENS, n = 5) analgesic neurostimulation (AN) for chronic intractable pain. Flexion reflex RIII was depressed or suppressed by AN in 11 patients (52.4%), while no modification was observed in 9 cases and a paradoxical increase during AN was evidenced in 1 case. In all but 2 patients, RIII changes were rapidly reversible after AN interruption. RIII depression was significantly associated with subjective pain relief, as assessed by conventional self-rating; moreover, in 2 patients it was possible to ameliorate the pain-suppressing effects of AN by selecting those stimulation parameters (intensity and frequency) that maximally depressed nociceptive reflex RIII. We recorded 2 cases of RIII attenuation after contralateral neurostimulation. AN appeared to affect nociceptive reflexes rather selectively, with no or very little effect on other cutaneous, non-nociceptive responses. Recording of RIII reflexes is relatively simple to implement as a routine paraclinical procedure. It facilitates the objective assessment of AN efficacy and may help to choose the most appropriate parameters of neurostimulation. In addition, RIII behavior in patients could be relevant to the understanding of some of the mechanisms involved in AN-induced pain relief.

  1. Physiological levels of blood coagulation factors IX and X control coagulation kinetics in an in vitro model of circulating tissue factor

    International Nuclear Information System (INIS)

    Tormoen, Garth W; Khader, Ayesha; Gruber, András; McCarty, Owen J T

    2013-01-01

    Thrombosis significantly contributes to cancer morbidity and mortality. The mechanism behind thrombosis in cancer may be circulating tissue factor (TF), as levels of circulating TF are associated with thrombosis. However, circulating TF antigen level alone has failed to predict thrombosis in patients with cancer. We hypothesize that coagulation factor levels regulate the kinetics of circulating TF-induced thrombosis. Coagulation kinetics were measured as a function of individual coagulation factor levels and TF particle concentration. Clotting times increased when pooled plasma was mixed at or above a ratio of 4:6 with PBS. Clotting times increased when pooled plasma was mixed at or above a ratio of 8:2 with factor VII-depleted plasma, 7:3 with factor IX- or factor X-depleted plasmas, or 2:8 with factor II-, V- or VIII-depleted plasmas. Addition of coagulation factors VII, X, IX, V and II to depleted plasmas shortened clotting and enzyme initiation times, and increased enzyme generation rates in a concentration-dependent manner. Only additions of factors IX and X from low-normal to high-normal levels shortened clotting times and increased enzyme generation rates. Our results demonstrate that coagulation kinetics for TF particles are controlled by factor IX and X levels within the normal physiological range. We hypothesize that individual patient factor IX and X levels may be prognostic for susceptibility to circulating TF-induced thrombosis. (paper)

  2. Stress-related psycho-physiological disorders: randomized single blind placebo controlled naturalistic study of psychometric evaluation using a radio electric asymmetric treatment

    Science.gov (United States)

    2011-01-01

    Background The aim of this study is to investigate the effects of a radio electric asymmetric treatment on psycho-physiological disorders (PPD). PPD are often stress related and are under the unconscious control of the patient and cannot be traced back to any serious physical disease. The brain stimulation treatment protocol used is called Neuro Psycho Physical Optimization (NPPO) with a Radio Electric Asymmetric Conveyer (REAC) device. Methods Psychological stress and PPD were measured for a group of 888 subjects using the Psychological Stress Measure (PSM) test, a self-administered questionnaire. Data were collected immediately before and after the 4-weeks of REAC treatment cycle. Results This study showed a significant reduction in scores measuring subjective perceptions of stress for subjects treated with a cycle of NPPO REAC treatment. At the end-point the number of subjects reporting symptoms of stress-related PPD on the PSM test was significantly reduced, whereas in the placebo group the difference was not significant. Conclusion A cycle of NPPO treatment with REAC was shown to reduce subjective perceptions of stress measured by the PSM test and in particular on PPD. Trial Registration This trial has been registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) with the number: ACTRN12607000463471. PMID:21771304

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

    Directory of Open Access Journals (Sweden)

    Tania E. Strahan

    2009-01-01

    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.

  4. Role of duodenal mucosal nerve endings in the acid-induced duodenogastric sensorimotor reflex: effect of benzocaine in healthy humans.

    Science.gov (United States)

    Vanuytsel, T; Karamanolis, G; Vos, R; Van Oudenhove, L; Farré, R; Tack, J

    2013-05-01

    Duodenal acid exposure induces a duodenogastric reflex resulting in gastric relaxation, inhibition of antral motility, and sensitization of the proximal stomach to distension. Duodenal hypersensitivity to acid has been identified as a potential pathogenic mechanism in functional dyspepsia. The nature and localization of the duodenal acid-sensitive receptors are still elusive. We hypothesize that acid directly activates superficial afferent nerve endings in the duodenal mucosa, triggering the duodenogastric reflex. In a double-blind, randomized, crossover study in 13 healthy volunteers, benzocaine, a local anesthetic, vs saline was perfused in the duodenum 15 min before duodenal acid perfusion. Gastric responses were monitored by a barostat. Stepwise isobaric gastric distensions were performed before and during acid perfusion. Symptoms were evaluated by visual analogue scales for six dyspeptic symptoms and an overall perception score. Benzocaine perfusion caused a relaxation of the stomach prior to duodenal acidification, indicating the existence of an excitatory duodenogastric tone. Pretreatment of the duodenum with benzocaine reduced the acid-induced gastric relaxation by 50% and abolished the inhibition of phasic motility of the proximal stomach. Finally, sensitization to distension was more pronounced in the benzocaine condition because of higher proximal gastric volumes. These findings support a model in which different neuronal subpopulations are responsible for the motor and sensory limb of the acid-sensitive duodenogastric reflex, making benzocaine an unsuitable drug to treat duodenal hypersensitivity to acid. These data provide more insight in the contribution of duodenal neuronal input to gastric physiology in the fasting state. © 2013 Blackwell Publishing Ltd.

  5. Differential effects of common variants in SCN2A on general cognitive ability, brain physiology, and messenger RNA expression in schizophrenia cases and control individuals.

    Science.gov (United States)

    Dickinson, Dwight; Straub, Richard E; Trampush, Joey W; Gao, Yuan; Feng, Ningping; Xie, Bin; Shin, Joo Heon; Lim, Hun Ki; Ursini, Gianluca; Bigos, Kristin L; Kolachana, Bhaskar; Hashimoto, Ryota; Takeda, Masatoshi; Baum, Graham L; Rujescu, Dan; Callicott, Joseph H; Hyde, Thomas M; Berman, Karen F; Kleinman, Joel E; Weinberger, Daniel R

    2014-06-01

    One approach to understanding the genetic complexity of schizophrenia is to study associated behavioral and biological phenotypes that may be more directly linked to genetic variation. To identify single-nucleotide polymorphisms associated with general cognitive ability (g) in people with schizophrenia and control individuals. Genomewide association study, followed by analyses in unaffected siblings and independent schizophrenia samples, functional magnetic resonance imaging studies of brain physiology in vivo, and RNA sequencing in postmortem brain samples. The discovery cohort and unaffected siblings were participants in the National Institute of Mental Health Clinical Brain Disorders Branch schizophrenia genetics studies. Additional schizophrenia cohorts were from psychiatric treatment settings in the United States, Japan, and Germany. The discovery cohort comprised 339 with schizophrenia and 363 community control participants. Follow-up analyses studied 147 unaffected siblings of the schizophrenia cases and independent schizophrenia samples including a total of an additional 668 participants. Imaging analyses included 87 schizophrenia cases and 397 control individuals. Brain tissue samples were available for 64 cases and 61 control individuals. We studied genomewide association with g, by group, in the discovery cohort. We used selected genotypes to test specific associations in unaffected siblings and independent schizophrenia samples. Imaging analyses focused on activation in the prefrontal cortex during working memory. Brain tissue studies yielded messenger RNA expression levels for RefSeq transcripts. The schizophrenia discovery cohort showed genomewide-significant association of g with polymorphisms in sodium channel gene SCN2A, accounting for 10.4% of g variance (rs10174400, P = 9.27 × 10(-10)). Control individuals showed a trend for g/genotype association with reversed allelic directionality. The genotype-by-group interaction was also genomewide

  6. Simultaneous characterizations of reflex and nonreflex dynamic and static changes in spastic hemiparesis

    Science.gov (United States)

    Chung, Sun G.; Ren, Yupeng; Liu, Lin; Roth, Elliot J.; Rymer, W. Zev

    2013-01-01

    This study characterizes tonic and phasic stretch reflex and stiffness and viscosity changes associated with spastic hemiparesis. Perturbations were applied to the ankle of 27 hemiparetic and 36 healthy subjects under relaxed or active contracting conditions. A nonlinear delay differential equation model characterized phasic and tonic stretch reflex gains, elastic stiffness, and viscous damping. Tendon reflex was characterized with reflex gain and threshold. Reflexively, tonic reflex gain was increased in spastic ankles at rest (P hemiparesis may help to evaluate and treat them more effectively. PMID:23636726

  7. Early rehabilitation in sepsis: a prospective randomised controlled trial investigating functional and physiological outcomes The i-PERFORM Trial (Protocol Article

    Directory of Open Access Journals (Sweden)

    Kayambu Geetha

    2011-10-01

    Full Text Available Abstract Background Patients with sepsis syndromes in comparison to general intensive care patients can have worse outcomes for physical function, quality of life and survival. Early intensive care rehabilitation can improve the outcome in general Intensive Care Unit (ICU patients, however no investigations have specifically looked at patients with sepsis syndromes. The 'i-PERFORM Trial' will investigate if early targeted rehabilitation is both safe and effective in patients with sepsis syndromes admitted to ICU. Methods/Design A single-centred blinded randomized controlled trial will be conducted in Brisbane, Australia. Participants (n = 252 will include those ≥ 18 years, mechanically ventilated for ≥ 48 hours and diagnosed with a sepsis syndrome. Participants will be randomised to an intervention arm which will undergo an early targeted rehabilitation program according to the level of arousal, strength and cardiovascular stability and a control group which will receive normal care. The primary outcome measures will be physical function tests on discharge from ICU (The Acute Care Index of Function and The Physical Function ICU Test. Health-related quality of life will be measured using the Short Form-36 and the psychological component will be tested using The Hospital Anxiety and Depression Scale. Secondary measures will include inflammatory biomarkers; Interleukin-6, Interleukin-10 and Tumour Necrosis Factor-α, peripheral blood mitochondrial DNA content and lactate, fat free muscle mass, tissue oxygenation and microcirculatory flow. Discussion The 'i-PERFORM Trial' will determine whether early rehabilitation for patients with sepsis is effective at improving patient outcomes with functional and physiological parameters reflecting long and short-term effects of early exercise and the safety in its application in critical illness. Trial Registration Australia and New Zealand Clinical Trials Register (ANZCTR: ACTRN12610000808044

  8. Interindividual differences in H reflex modulation during normal walking

    DEFF Research Database (Denmark)

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

    2002-01-01

    was greater for the S group. The hip joint moment was similar for the groups. The EMG activity in the vastus lateralis and anterior tibial muscles was greater prior to heel strike for the S group. These data indicate that human walking exhibits at least two different motor patterns as evaluated by gating...... of afferent input to the spinal cord, by EMG activity and by walking mechanics. Increasing H reflex excitability during the swing phase appears to protect the subject against unexpected perturbations around heel strike by a facilitated stretch reflex in the triceps surae muscle. Alternatively, in subjects...... with a suppressed H reflex in the swing phase the knee joint extensors seem to form the primary protection around heel strike....

  9. Spasm of the near reflex: a spectrum of anomalies.

    Science.gov (United States)

    Goldstein, J H; Schneekloth, B B

    1996-01-01

    Spasm of the near reflex has been characterized as the variable appearance of pseudomyopia, convergent strabismus and miosis. These characteristics may appear together or separately. In addition, abnormalities of accommodation may appear not only as pseudomyopia, but may also be manifest in cases with significant hypermetropia in which the patient is unable to relax accommodation even when plus lenses are used. The intent of this review is to identify the various clinical presentations of anomalies of the entire near reflex as well as the component parts. The relationship to functional and organic disorders are discussed as well as the related neuroanatomy. We suggest that one may more readily understand the clinical manifestations as a spectrum of anomalies of the near reflex rather than a multitude of disconnected entities.

  10. A critical reflexive Perspective on othering in collaborative knowledge production

    DEFF Research Database (Denmark)

    Jakobsen, Helle Nordentoft; Olesen, Birgitte Ravn

    2018-01-01

    Purpose The purpose of the article is to show power mechanisms of in- and exclusion in moments where certain participants appeared to be othered in two collaborative research and development projects in a health care setting. Design/methodology/approach The article contributes to critical......-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...

  11. Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

    Science.gov (United States)

    Delwaide, P J; Figiel, C; Richelle, C

    1977-06-01

    The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

  12. FEFsem neuronal response during combined volitional and reflexive pursuit.

    Science.gov (United States)

    Bakst, Leah; Fleuriet, Jérome; Mustari, Michael J

    2017-05-01

    Although much is known about volitional and reflexive smooth eye movements individually, much less is known about how they are coordinated. It is hypothesized that separate cortico-ponto-cerebellar loops subserve these different types of smooth eye movements. Specifically, the MT-MST-DLPN pathway is thought to be critical for ocular following eye movements, whereas the FEF-NRTP pathway is understood to be vital for volitional smooth pursuit. However, the role that these loops play in combined volitional and reflexive behavior is unknown. We used a large, textured background moving in conjunction with a small target spot to investigate the eye movements evoked by a combined volitional and reflexive pursuit task. We also assessed the activity of neurons in the smooth eye movement subregion of the frontal eye field (FEFsem). We hypothesized that the pursuit system would show less contribution from the volitional pathway in this task, owing to the increased involvement of the reflexive pathway. In accordance with this hypothesis, a majority of FEFsem neurons (63%) were less active during pursuit maintenance in a combined volitional and reflexive pursuit task than during purely volitional pursuit. Interestingly and surprisingly, the neuronal response to the addition of the large-field motion was highly correlated with the neuronal response to a target blink. This suggests that FEFsem neuronal responses to these different perturbations-whether the addition or subtraction of retinal input-may be related. We conjecture that these findings are due to changing weights of both the volitional and reflexive pathways, as well as retinal and extraretinal signals.

  13. Automated data reduction workflows for astronomy. The ESO Reflex environment

    Science.gov (United States)

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

    2013-11-01

    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

  14. [From dissociation to system: The concept of the unconscious as a descendant of the reflex paradigm in Freud].

    Science.gov (United States)

    Janssen, Sandra

    2009-03-01

    The paper tries to situate Freud's theory historically by referring it to a paradigm of psychological theory that Marcel Gauchet describes as the "Golden Age" of psychophysics and reflex theory, and that he situates between 1870 and 1900. I will show that until 1900 Freud thinks, in fact, in categories that correspond to this type of thought. His texts On the Psychical Mechanism of Hysterical Phenomena (1893, with Josef Breuer) and A Project for a Scientific Psychology (1895) still follow the conception of a psychological subject on the basis of the stimulus and response model, which can be found in numerous contemporaneous authors. In this model, the psyche is just a place of transit open to the exterior, and its unity can only be a sum of elements of consciousness having a physiological substrate. Nevertheless, Freud's early texts--although appertaining to the reflex paradigm--already contain elements that serve to construct another basic model of the psychic apparatus, which is finally introduced by The Interpretation of Dreams. Those new elements are the separation between interior and exterior, the introduction of endogenous energy, which is linked to the importance of emotions instead of sensations, and the problem of the adaptation to outer reality that results from it. Nevertheless, once more Freud is not the only theorist in whose thought the new paradigm can be found; I again refer his new premises to other contemporary psychologists. The question that arises from Freud's passage from one paradigm to another is how he handles the continuity of his own thought. I describe the difficult compromise between contradictory concepts he finds in his Project for a Scientific Psychology; but certain concepts that derive from the reflex paradigm subsist even during the later development of psychoanalysis. This is especially the case for the concept of the unconscious itself: As I argue, this concept originates in the reflex paradigm, and, in contrast to contemporary

  15. Neurophysiology and Clinical Implications of the Laryngeal Adductor Reflex.

    Science.gov (United States)

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

    2013-09-01

    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.

  16. A Combination of Central Pattern Generator-based and Reflex-based Neural Networks for Dynamic, Adaptive, Robust Bipedal Locomotion

    DEFF Research Database (Denmark)

    Di Canio, Giuliano; Larsen, Jørgen Christian; Wörgötter, Florentin

    2016-01-01

    Robotic systems inspired from humans have always been lightening up the curiosity of engineers and scientists. Of many challenges, human locomotion is a very difficult one where a number of different systems needs to interact in order to generate a correct and balanced pattern. To simulate...... the interaction of these systems, implementations with reflexbased or central pattern generator (CPG)-based controllers have been tested on bipedal robot systems. In this paper we will combine the two controller types, into a controller that works with both reflex and CPG signals. We use a reflex-based neural...... network to generate basic walking patterns of a dynamic bipedal walking robot (DACBOT) and then a CPG-based neural network to ensure robust walking behavior...

  17. A tissue dose-based comparative exposure assessment of manganese using physiologically based pharmacokinetic modeling—The importance of homeostatic control for an essential metal

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, P. Robinan, E-mail: rgentry@ramboll.com [Ramboll Environ US Corporation, 3701 Armand St., Monroe, LA 71201 (United States); Van Landingham, Cynthia; Fuller, William G. [Ramboll Environ US Corporation, 3701 Armand St., Monroe, LA 71201 (United States); Sulsky, Sandra I. [Ramboll Environ US Corporation, Amherst, MA (United States); Greene, Tracy B. [Ramboll Environ US Corporation, 3701 Armand St., Monroe, LA 71201 (United States); Clewell, Harvey J.; Andersen, Melvin E. [ScitoVation, RTP, NC (United States); Roels, Harry A. [Université Catholique de Louvain, Brussels (Belgium); Taylor, Michael D. [NIPERA, Durham, NC (United States); Keene, Athena M. [Afton Chemical Corporation, Richmond, VA (United States)

    2017-05-01

    A physiologically-based pharmacokinetic (PBPK) model (Schroeter et al., 2011) was applied to simulate target tissue manganese (Mn) concentrations following occupational and environmental exposures. These estimates of target tissue Mn concentrations were compared to determine margins of safety (MOS) and to evaluate the biological relevance of applying safety factors to derive acceptable Mn air concentrations. Mn blood concentrations measured in occupational studies permitted verification of the human PBPK models, increasing confidence in the resulting estimates. Mn exposure was determined based on measured ambient air Mn concentrations and dietary data in Canada and the United States (US). Incorporating dietary and inhalation exposures into the models indicated that increases in target tissue concentrations above endogenous levels only begin to occur when humans are exposed to levels of Mn in ambient air (i.e. > 10 μg/m{sup 3}) that are far higher than those currently measured in Canada or the US. A MOS greater than three orders of magnitude was observed, indicating that current Mn air concentrations are far below concentrations that would be required to produce the target tissue Mn concentrations associated with subclinical neurological effects. This application of PBPK modeling for an essential element clearly demonstrates that the conventional application of default factors to “convert” an occupational exposure to an equivalent continuous environmental exposure, followed by the application of safety factors, is not appropriate in the case of Mn. PBPK modeling demonstrates that the relationship between ambient Mn exposures and dose-to-target tissue is not linear due to normal tissue background levels and homeostatic controls. - Highlights: • Manganese is an essential nutrient, adding complexity to its risk assessment. • Nonlinearities in biological processes are important for manganese risk assessment. • A PBPK model was used to estimate target tissue

  18. Low-calorie energy drink improves physiological response to exercise in previously sedentary men: a placebo-controlled efficacy and safety study.

    Science.gov (United States)

    Lockwood, Christopher M; Moon, Jordan R; Smith, Abbie E; Tobkin, Sarah E; Kendall, Kristina L; Graef, Jennifer L; Cramer, Joel T; Stout, Jeffrey R

    2010-08-01

    Energy drink use has grown despite limited research to support efficacy or safety and amid concerns when combined with exercise. The purpose of this study was to assess the effects of 10 weeks of once-daily energy drink consumption or energy drink consumption with exercise on measures of body composition, cardiorespiratory fitness, strength, mood, and safety in previously sedentary males. Thirty-eight males were randomly assigned to energy drink + exercise (EX-A), energy drink (NEX-A), placebo + exercise (EX-B), or placebo (NEX-B). All participants consumed 1 drink per day for 10 weeks; EX-A and EX-B participated in 10 weeks of resistance and endurance exercise. Testing was performed before (PRE) and after (POST) the 10-week intervention. No significant (p > 0.05) changes were observed for body composition, fitness, or strength in NEX-A; however, significantly greater decreases in fat mass and percentage body fat and increases in VO2peak were observed in EX-A versus EX-B. Ventilatory threshold (VT), minute ventilation, VO2 at VT, and power output at VT improved significantly PRE to POST in EX-A but not in EX-B or nonexercising groups. Clinical markers for hepatic, renal, cardiovascular, and immune function, as determined by PRE and POST blood work revealed no adverse effects in response to the energy drink. Mood was not affected by energy drink use. Absent energy restriction or other dietary controls, chronic ingestion of a once-daily low-calorie energy drink appears ineffective at improving body composition, cardiorespiratory fitness, or strength in sedentary males. However, when combined with exercise, preworkout energy drink consumption may significantly improve some physiological adaptations to combined aerobic and resistance training.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Reduced depression of transmitter release from Ia afferents following previous activation (post-activation depression) has been suggested to be involved in the pathophysiology of spasticity. However, the effect of this mechanism on the myotatic reflex and its possible contribution to increased...... reflex excitability in spastic participants has not been tested. To investigate these effects, we examined post-activation depression in Soleus H-reflex responses and in mechanically evoked Soleus stretch reflex responses. Stretch reflex responses were evoked with consecutive dorsiflexion perturbations...... of the soleus stretch reflex and H-reflex decreased as the interval between the stimulus/perturbation was decreased. Similarly, the stretch-evoked torque decreased. In the spastic participants, the post-activation depression of both reflexes and the stretch-evoked torque was significantly smaller than...

  20. The contribution of a central pattern generator in a reflex-based neuromuscular model

    Science.gov (United States)

    Dzeladini, Florin; van den Kieboom, Jesse; Ijspeert, Auke

    2014-01-01

    Although the concept of central pattern generators (CPGs) controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s’ demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented. The results highlight the advantages of a CPG as feedforward component in terms of gait modulation. PMID:25018712

  1. The Contribution of a Central Pattern Generator in a Reflex-Based Neuromuscular Model

    Directory of Open Access Journals (Sweden)

    Florin eDzeladini

    2014-06-01

    Full Text Available Although the concept of central pattern generators (CPGs controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s' demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented.The results highlight the advantages that a feedforward component can have in terms of gait modulation.

  2. Child–Computer Interaction at the Beginner Stage of Music Learning: Effects of Reflexive Interaction on Children’s Musical Improvisation

    Science.gov (United States)

    Addessi, Anna Rita; Anelli, Filomena; Benghi, Diber; Friberg, Anders

    2017-01-01

    In this article children’s musical improvisation is investigated through the “reflexive interaction” paradigm. We used a particular system, the MIROR-Impro, implemented in the framework of the MIROR project (EC-FP7), which is able to reply to the child playing a keyboard by a “reflexive” output, mirroring (with repetitions and variations) her/his inputs. The study was conducted in a public primary school, with 47 children, aged 6–7. The experimental design used the convergence procedure, based on three sample groups allowing us to verify if the reflexive interaction using the MIROR-Impro is necessary and/or sufficient to improve the children’s abilities to improvise. The following conditions were used as independent variables: to play only the keyboard, the keyboard with the MIROR-Impro but with not-reflexive reply, the keyboard with the MIROR-Impro with reflexive reply. As dependent variables we estimated the children’s ability to improvise in solos, and in duets. Each child carried out a training program consisting of 5 weekly individual 12 min sessions. The control group played the complete package of independent variables; Experimental Group 1 played the keyboard and the keyboard with the MIROR-Impro with not-reflexive reply; Experimental Group 2 played only the keyboard with the reflexive system. One week after, the children were asked to improvise a musical piece on the keyboard alone (Solo task), and in pairs with a friend (Duet task). Three independent judges assessed the Solo and the Duet tasks by means of a grid based on the TAI-Test for Ability to Improvise rating scale. The EG2, which trained only with the reflexive system, reached the highest average results and the difference with EG1, which did not used the reflexive system, is statistically significant when the children improvise in a duet. The results indicate that in the sample of participants the reflexive interaction alone could be sufficient to increase the improvisational

  3. Effects of bromantan on offspring maturation and development of reflexes.

    Science.gov (United States)

    Iezhitsa, I N; Spasov, A A; Bugaeva, L I

    2001-01-01

    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

  4. Reflexion and control mathematical models

    CERN Document Server

    Novikov, Dmitry A

    2014-01-01

    This book is dedicated to modern approaches to mathematical modeling of reflexive processes in control. The authors consider reflexive games that describe the gametheoretical interaction of agents making decisions based on a hierarchy of beliefs regarding (1) essential parameters (informational reflexion), (2) decision principles used by opponents (strategic reflexion), (3) beliefs about beliefs, and so on. Informational and reflexive equilibria in reflexive games generalize a series of well-known equilibrium concepts in noncooperative games and models of collective behavior. These models allow posing and solving the problems of informational and reflexive control in organizational, economic, social and other systems, in military applications, etc. (the interested reader will find in the book over 30 examples of possible applications in these fields) and describing uniformly many psychological/sociological phenomena connected with reflexion, viz., implicit control, informational control via the mass media, re...

  5. Acid-sensing ion channels contribute to the metaboreceptor component of the exercise pressor reflex

    OpenAIRE

    McCord, Jennifer L.; Tsuchimochi, Hirotsugu; Kaufman, Marc P.

    2009-01-01

    The exercise pressor reflex is evoked by both mechanical and metabolic stimuli arising in contracting skeletal muscle. Recently, the blockade of acid-sensing ion channels (ASICs) with amiloride and A-316567 attenuated the reflex. Moreover, amiloride had no effect on the mechanoreceptor component of the reflex, prompting us to determine whether ASICs contributed to the metaboreceptor component of the exercise pressor reflex. The metaboreceptor component can be assessed by measuring mean arteri...

  6. Physiology of bile secretion.

    Science.gov (United States)

    Esteller, Alejandro

    2008-10-07

    The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

  7. Practicing Reflexivity in the Study of Italian Migrants in London

    Science.gov (United States)

    Seganti, Francesca Romana

    2010-01-01

    This article discusses the centrality of reflexivity in qualitative research through examples from my study on the role new media play in the lives of Italians in London. My hypothesis was that Italians were "in transit" in London and they were using new media to build "temporary" communities. I conducted in-depth interviews…

  8. Teaching Reflexivity: Undoing or Reinscribing Habits of Gender?

    Science.gov (United States)

    Bondi, Liz

    2009-01-01

    This paper outlines an approach used in a course designed to teach reflexivity as a research skill and explores what kind of gender intervention such teaching might constitute. Although inspired by feminist debates about the complex power dynamics of research relationships, the course in question does not focus specifically on gender issues.…

  9. Caught in Uncertain Futures, Now: A Reflexive Moment

    Science.gov (United States)

    Reyes, Reynaldo, III

    2016-01-01

    This reflexive vignette reveals the emotional risks of ethnographic work by a Chicano researcher, educator, and advocate doing work in the Texas-Mexico Borderlands, caught at the intersection of vulnerable Latina/o youth and their possible futures. Data in this creative piece are derived from field notes of one classroom observation from an…

  10. Spasm of the near reflex associated with head injury.

    Science.gov (United States)

    Knapp, Christopher; Sachdev, Arun; Gottlob, Irene

    2002-03-01

    Spasm of the near reflex is characterized by intermittent miosis, convergence spasm and pseudomyopia with blurred vision at distance. Usually, it is a functional disorder in young patients with underlying emotional problems. Only rarely is it caused by organic disorder. We report a patient who developed convergent spasm associated with miosis after head trauma at the age of 84 years.

  11. Polyphony in the Classroom: Reporting Narrative Action Research Reflexively

    Science.gov (United States)

    Niemi, Reetta; Heikkinen, Hannu L. T.; Kannas, Lasse

    2010-01-01

    In this article we will present a reflexive way of producing a narrative analysis on teaching and learning that involves all participants of the pedagogical process. Our theoretical contribution rests on the concept "lived pedagogy", adapted from Max van Manen's term "lived experience". Like van Manen, we start by asking the…

  12. Vestibulo-ocular reflex and the head impulse test

    Directory of Open Access Journals (Sweden)

    Eliana T. Maranhão

    2012-12-01

    Full Text Available The authors highlights the importance of the vestibulo-ocular reflex examination through the head impulse test as a diagnostic method for vestibular dysfunction as well as, and primarily, a bedside semiotic resource capable of differentiating between acute peripheral vestibulopathy and a cerebellar or brainstem infarction in emergency rooms.

  13. Team performance in the Italian NHS: the role of reflexivity.

    Science.gov (United States)

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

    2018-04-09

    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.

  14. Reflex sympathetic dystrophy/complex regional pain syndrome, type 1

    African Journals Online (AJOL)

    Enrique

    with MRI every 3 months and the bone marrow oedema disappeared after 6 months. Introduction ... SA JOURNAL OF RADIOLOGY • August 2004. Reflex sympathetic dystrophy/complex regional pain syndrome, type 1 ... may be either trauma of external origin or iatrogenic, post surgery. In some patients particularly children ...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    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...

  16. Approaching Reflexivity through Reflection: Issues for Critical Management Education

    Science.gov (United States)

    Hibbert, Paul

    2013-01-01

    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. Modulation of the masseteric reflex by gastric vagal afferents.

    Science.gov (United States)

    Pettorossi, V E

    1983-04-01

    Several investigations have shown that the vagal nerve can affect the reflex responses of the masticatory muscles acting at level either of trigeminal motoneurons or of the mesencephalic trigeminal nucleus (MTN). The present experiments have been devoted to establish the origin of the vagal afferent fibres involved in modulating the masseteric reflex. In particular, the gastric vagal afferents were taken into consideration and selective stimulations of such fibres were performed in rabbit. Conditioning electrical stimulation of truncus vagalis ventralis (TVV) reduced the excitability of the MTN cells as shown by a decrease of the antidromic response recorded from the semilunar ganglion and elicited by MTN single-shock electrical stimulation. Sympathetic and cardiovascular influences were not involved in these responses. Mechanical stimulation of gastric receptors, by means of gastric distension, clearly diminished the amplitude of twitch tension of masseteric reflex and inhibited the discharge frequency of proprioceptive MTN units. The effect was phasic and depended upon the velocity of distension. Thus the sensory volleys originating from rapid adapting receptors reach the brain stem through vagal afferents and by means of a polysynaptic connection inhibits the masseteric reflex at level of MTN cells.

  18. Pure nuclear reflexes and combined hyperfine interactions in YIG

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, H; Eisberg, R; Alp, E; Rueffer, R; Gerdau, E; Lauer, S; Trautwein, A X; Grodzicki, M; Vera, A

    1983-01-01

    Moessbauer spectra of oriented YIG single crystals were taken and the numerical analysis using the transmission integral yielded a consistent set of hyperfine interaction parameters. They are in good agreement with theoretical values obtained by MO-calculations which included clusters up to 62 ions. Finally pure nuclear reflexes are predicted for single crystals and two theoretical spectra are given.

  19. Reconceptualizing reflexivity and dissonance in professional and personal domains.

    Science.gov (United States)

    Brooks, Ann

    2008-09-01

    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.

  20. 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.

    2015-01-01

    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.

  1. PhD Students, Interculturality, Reflexivity, Community and Internationalisation

    Science.gov (United States)

    Holliday, Adrian

    2017-01-01

    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…

  2. A reflexing electron microwave amplifier for rf particle accelerator applications

    International Nuclear Information System (INIS)

    Fazio, M.V.; Hoeberling, R.F.

    1988-01-01

    The evolution of rf-accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave power sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing-electron class of sources can produce microwave powers at the gigawatt level and has demonstrated operation from 800-MHz to 40-GHz. The pulse length appears to be limited by diode closure, and reflexing-electron devices have been operated in a repetitively pulsed mode. A design is presented for a reflexing electron microwave amplifier that is frequency and phase locked. In this design, the generated microwave power can be efficiently coupled to one or several accelerator loads. Frequency and phase-locking capability may permit parallel-source operation for higher power. The low-frequency (500-MHz to 10-GHz) operation at very high power required by present and proposed microwave particle accelerators makes an amplifier, based on reflexing electron phenomena, a candidate for the development of new accelerator power sources. (author)

  3. Supporting relationships in reflexive movements in leadership and organisational research

    DEFF Research Database (Denmark)

    Mortensen, Ann Rubens

    , and the actions in these relationships have profound and long-lasting effects above and beyond the immediate context, i.e., the organisation. I am offering a systemic social constructionist perspective on reflexivity in leadership and organisational research, bringing forth a way of creating connections...

  4. Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

    International Nuclear Information System (INIS)

    El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

    2012-01-01

    We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

  5. THE CONCEPT OF REFLEXIVE MANAGEMENT OF CONSUMER DEMAND

    Directory of Open Access Journals (Sweden)

    Maryna Mavrina

    2017-11-01

    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

  6. 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

    2002-01-01

    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...

  7. Cervico-ocular Reflex Is Increased in People With Nonspecific Neck Pain.

    Science.gov (United States)

    de Vries, Jurryt; Ischebeck, Britta K; Voogt, Lennard P; Janssen, Malou; Frens, Maarten A; Kleinrensink, Gert-Jan; van der Geest, Jos N

    2016-08-01

    Neck pain is a widespread complaint. People experiencing neck pain often present an altered timing in contraction of cervical muscles. This altered afferent information elicits the cervico-ocular reflex (COR), which stabilizes the eye in response to trunk-to-head movements. The vestibulo-ocular reflex (VOR) elicited by the vestibulum is thought to be unaffected by afferent information from the cervical spine. The aim of the study was to measure the COR and VOR in people with nonspecific neck pain. This study utilized a cross-sectional design in accordance with the STROBE statement. An infrared eye-tracking device was used to record the COR and the VOR while the participant was sitting on a rotating chair in darkness. Eye velocity was calculated by taking the derivative of the horizontal eye position. Parametric statistics were performed. The mean COR gain in the control group (n=30) was 0.26 (SD=0.15) compared with 0.38 (SD=0.16) in the nonspecific neck pain group (n=37). Analyses of covariance were performed to analyze differences in COR and VOR gains, with age and sex as covariates. Analyses of covariance showed a significantly increased COR in participants with neck pain. The VOR between the control group, with a mean VOR of 0.67 (SD=0.17), and the nonspecific neck pain group, with a mean VOR of 0.66 (SD=0.22), was not significantly different. Measuring eye movements while the participant is sitting on a rotating chair in complete darkness is technically complicated. This study suggests that people with nonspecific neck pain have an increased COR. The COR is an objective, nonvoluntary eye reflex and an unaltered VOR. This study shows that an increased COR is not restricted to patients with traumatic neck pain. © 2016 American Physical Therapy Association.

  8. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  9. Plant Physiology in Greenhouses

    NARCIS (Netherlands)

    Heuvelink, E.; Kierkels, T.

    2015-01-01

    Since 2004 Ep Heuvelink and Tijs Kierkels have been writing a continuing series of plant physiology articles for the Dutch horticultural journal Onder Glas and the international edition In Greenhouses. The book Plant Physiology in Greenhouses consists of 50 of their plant physiology articles. The

  10. Reflexive intergroup bias in third-party punishment.

    Science.gov (United States)

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

    2016-11-01

    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).

  11. [The lombard reflex as a test of vocal function (author's transl)].

    Science.gov (United States)

    Schultz-Coulon, H J; Fues, C P

    1976-06-01

    Any impairment of audio-phonatory control by background noise is followed by an increase in both the intensity and pitch of the speaking voice (Lombard reflex, 1911), thus increasing vocal strain. As a consequence, it might be anticipated that persons reacting to noise with marked changes in voice might be more liable to develop dysphonia. 22 singers, 34 normal controls, and 22 patients with hyperfunctional dysphonia where studied. In all patients, both ears were gradually masked with white noise. The change of the mean intensity level and of the mean pitch level of the speaking voice were then measured objectively with a special fundamental frequency analyzer (Fedders and Schultz-Coulon, 1975). Results show that the increase of intensity is comparable in all subjects, whereas the elevation of the mean pitch level differs significantly: trained voices (singers) react with the least pitch increment whereas dysphonic patients react with the most. The following conclusions were made from the present investigation: 1. Extreme increments in pitch level can be considered to be a more significant etiological factor of dysphonia than intensity increments; 2. Vocal therapy and voice training may have a favorable effect on the Lombard reflex (probably by improvement of the kinesthetic control mechanism) so that the speaking voice in a noisy environment is raised less with less vocal strain. The study also indicates that measurement of pitch changes during binaural masking can provide important information for the diagnosis, therapy and prophylaxis of dysphonia.

  12. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

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

    Directory of Open Access Journals (Sweden)

    Christian Iber

    2017-02-01

    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.

  14. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

    Science.gov (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

    2017-02-01

    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.

  15. Behavioral and physiological methods for early quantitative assessment of spinal cord injury and prognosis in rats

    Directory of Open Access Journals (Sweden)

    C.A. Giglio

    2006-12-01

    Full Text Available Methods for reliable evaluation of spinal cord (SC injury in rats at short periods (2 and 24 h after lesion were tested to characterize the mechanisms implicated in primary SC damage. We measured the physiological changes occurring after several procedures for producing SC injury, with particular emphasis on sensorimotor functions. Segmental and suprasegmental reflexes were tested in 39 male Wistar rats weighing 250-300 g divided into three control groups that were subjected to a anesthesia, b dissection of soft prevertebral tissue, and c laminectomy of the vertebral segments between T10 and L1. In the lesion group the SC was completely transected, hemisected or subjected to vertebral compression. All animals were evaluated 2 and 24 h after the experimental procedure by the hind limb motility index, Bohlman motor score, open-field, hot-plate, tail flick, and paw compression tests. The locomotion scale proved to be less sensitive than the sensorimotor tests. A reduction in exploratory movements was detected in the animals 24 h after the procedures. The hot-plate was the most sensitive test for detecting sensorimotor deficiencies following light, moderate or severe SC injury. The most sensitive and simplest test of reflex function was the hot-plate. The hemisection model promoted reproducible moderate SC injury which allowed us to quantify the resulting behavior and analyze the evolution of the lesion and its consequences during the first 24 h after injury. We conclude that hemisection permitted the quantitation of behavioral responses for evaluation of the development of deficits after lesions. Hind limb evaluation scores and spontaneous exploration events provided a sensitive index of immediate injury effects after SC lesion at 2 and 24 h. Taken together, locomotion scales, open-field, and hot-plate tests represent reproducible, quantitatively sensitive methods for detecting functional deficiencies within short periods of time, indicating their

  16. Decomposing the impacts of overeducation and overskilling on earnings and job satisfaction: An analysis using REFLEX data

    OpenAIRE

    Sánchez-Sáncheza, Nuria; McGuinness, Seamus

    2011-01-01

    This article assesses the extent to which the impact of overeducation and overskilling on labour market outcomes such as earnings and job satisfaction relate to mismatches in particular competency areas. The analysis uses REFLEX data, which collects information about 19 key competence areas related to job performance. We find that the penalties to both forms of mismatch are insensitive to the inclusion of controls for overskilling in a wide range of jobspecific competencies. The research sugg...

  17. Local vibration inhibits H-reflex but does not compromise manual dexterity and does not increase tremor.

    Science.gov (United States)

    Budini, Francesco; Laudani, Luca; Bernardini, Sergio; Macaluso, Andrea

    2017-10-01

    The present work aimed at investigating the effects of local vibration on upper limb postural and kinetic tremor, on manual dexterity and on spinal reflex excitability. Previous studies have demonstrated a decrease in spinal reflex excitability and in force fluctuations in the lower limb but an increase in force fluctuation in the upper limbs. As hand steadiness is of vital importance in many daily-based tasks, and local vibration may also be applied in movement disorders, we decided to further explore this phenomenon. Ten healthy volunteers (26±3years) were tested for H reflex, postural and kinetic tremor and manual dexterity through a Purdue test. EMG was recorded from flexor carpi radialis (FCR) and extensor digitorum communis (EDC). Measurements were repeated at baseline, after a control period during which no vibration was delivered and after vibration. Intervention consisted in holding for two minutes a vibrating handle (frequency 75Hz, displacement∼7mm), control consisted in holding for two minutes the same handle powered off. Reflex excitability decreased after vibration whilst postural tremor and manual dexterity were not affected. Peak kinetic tremor frequency increased from baseline to control measurements (P=0.002). Co-activation EDC/FCR increased from control to vibration (P=0.021). These results show that two minutes local vibration lead to a decrease in spinal excitability, did not compromise manual dexterity and did not increase tremor; however, in contrast with expectations, tremor did not decrease. It is suggested that vibration activated several mechanisms with opposite effects, which resulted in a neutral outcome on postural and kinetic tremor. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Conservation physiology of animal migration

    Science.gov (United States)

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  19. Deterioração controlada para avaliar o potencial fisiológico de sementes de beterraba Controlled deterioration to evaluate the physiological potential of beetroot seeds

    Directory of Open Access Journals (Sweden)

    Josué B Silva

    2012-09-01

    Full Text Available Sementes de hortaliças quase sempre apresentam elevado valor comercial, motivo pelo qual devem ter o potencial fisiológico eficientemente avaliado. O teste de deterioração controlada é um dos recomendados para avaliação do vigor de sementes pequenas, como as de beterraba. O objetivo do trabalho foi determinar o melhor procedimento para a condução de referido teste em sementes de beterraba e sua relação com a emergência de plântulas em campo. Foram utilizados sete lotes de sementes da cultivar Top Tall Early Wonder, adquiridos no comércio. Após lavagem em água corrente, as sementes foram submetidas aos testes de germinação, velocidade de germinação, envelhecimento acelerado, emergência de plântulas em campo, velocidade de emergência e deterioração controlada (temperaturas de 41 e 45ºC, teores de água de 22, 24 e 26% e períodos de exposição de 12, 24 e 36 horas. As combinações 41ºC/24%/12 h, 41ºC/24%/36 h, 41ºC/26%/36 h e 45ºC/24%/24 h apresentaram potencial para uso na avaliação do vigor de sementes de beterraba. No entanto, sob as combinações de 41°C/24%/12 h ou 45°C/24%/24 h reduziu-se o tempo de condução do teste.Seeds of vegetable crop species always present high commercial value, so the physiological potential must be efficiently evaluated. The controlled deterioration is a recommended test to evaluate seed vigor of small-seeded vegetable crops, such as beetroot seeds. This research was run in order to determine the best controlled deterioration test procedures for beetroot seeds and its relationship with field seedling emergence. Seven commercial seed lots of the cultivar Top Tall Early Wonder were used. After washing in running water, the seeds were tested for germination, speed of germination, accelerated aging, seedling field emergence, emergence rate and controlled deterioration (41 and 45°C, moisture contents of 22, 24 and 26% and exposure times of 12, 24 and 36 hours. The combination of 41

  20. Growth and mebrane lipid composition in cucumber : Morphological and physiological differences between two low temperature tolerant cucumber lines and a control

    NARCIS (Netherlands)

    Bulder, Hermana Adriana Maria

    1992-01-01

    The aim of the investigation was to get more insight into the physiological background of a better fuctioning of cucumber plants under a suboptimal temperature regime (20/12˚C day/night instead of 25/20˚C day/night) and low light condtitions. Young cucumber platns were uesd with the goals of

  1. A new hypothesis of cause of syncope: trigeminocardiac reflex during extraction of teeth.

    Science.gov (United States)

    Arakeri, Gururaj; Arali, Veena

    2010-02-01

    Transient Loss Of Consciousness (TLOC) or vasovagal syncope is well known phenomenon in dental/maxillofacial surgery. Despite considerable study of vasovagal syncope, its pathophysiology remains to be fully elucidated. After having encountered a case of trigeminocardiac reflex after extraction of maxillary first molar we observed and studied 400 extractions under local anesthesia to know the relation between trigeminocardiac reflex and syncope. We make hypothesis that trigeminocardiac reflex which is usually seen under general anesthesia when all sympathetic reflexes are blunted can also occur under local anesthesia during extractions of maxillary molars (dento-cardiac reflex) and mediate syncope.

  2. Feedforward neural control of toe walking in humans.

    Science.gov (United States)

    Lorentzen, Jakob; Willerslev-Olsen, Maria; Hüche Larsen, Helle; Svane, Christian; Forman, Christian; Frisk, Rasmus; Farmer, Simon Francis; Kersting, Uwe; Nielsen, Jens Bo

    2018-03-23

    Activation of ankle muscles at ground contact during toe walking is unaltered when sensory feedback is blocked or the ground is suddenly dropped. Responses in the soleus muscle to transcranial magnetic stimulation, but not peripheral nerve stimulation, are facilitated at ground contact during toe walking. We argue that toe walking is supported by feedforward control at ground contact. Toe walking requires careful control of the ankle muscles in order to absorb the impact of ground contact and maintain a stable position of the joint. The present study aimed to clarify the peripheral and central neural mechanisms involved. Fifteen healthy adults walked on a treadmill (3.0 km h -1 ). Tibialis anterior (TA) and soleus (Sol) EMG, knee and ankle joint angles, and gastrocnemius-soleus muscle fascicle lengths were recorded. Peripheral and central contributions to the EMG activity were assessed by afferent blockade, H-reflex testing, transcranial magnetic brain stimulation (TMS) and sudden unloading of the planter flexor muscle-tendon complex. Sol EMG activity started prior to ground contact and remained high throughout stance. TA EMG activity, which is normally seen around ground contact during heel strike walking, was absent. Although stretch of the Achilles tendon-muscle complex was observed after ground contact, this was not associated with lengthening of the ankle plantar flexor muscle fascicles. Sol EMG around ground contact was not affected by ischaemic blockade of large-diameter sensory afferents, or the sudden removal of ground support shortly after toe contact. Soleus motor-evoked potentials elicited by TMS were facilitated immediately after ground contact, whereas Sol H-reflexes were not. These findings indicate that at the crucial time of ankle stabilization following ground contact, toe walking is governed by centrally mediated motor drive rather than sensory driven reflex mechanisms. These findings have implications for our understanding of the control of

  3. Anxiety and Depression Symptom Dimensions Demonstrate Unique Relationships with the Startle Reflex in Anticipation of Unpredictable Threat in 8 to 14 Year-Old Girls.

    Science.gov (United States)

    Nelson, Brady D; Hajcak, Greg

    2017-02-01

    There is growing evidence that heightened sensitivity to unpredictability is a core mechanism of anxiety disorders. In adults, multiple anxiety disorders have been associated with a heightened startle reflex in anticipation of unpredictable threat. Child and adolescent anxiety has been linked to an increased startle reflex across baseline, safety, and threat conditions. However, it is unclear whether anxiety in youth is related to the startle reflex as a function of threat predictability. In a sample of 90 8 to 14 year-old girls, the present study examined the association between anxiety symptom dimensions and startle potentiation during a no, predictable, and unpredictable threat task. Depression symptom dimensions were also examined given their high comorbidity with anxiety and mixed relationship with the startle reflex and sensitivity to unpredictability. To assess current symptoms, participants completed the self-report Screen for Child Anxiety Related Emotional Disorders and Children's Depression Inventory. Results indicated that social phobia symptoms were associated with heightened startle potentiation in anticipation of unpredictable threat and attenuated startle potentiation in anticipation of predictable threat. Negative mood and negative self-esteem symptoms were associated with attenuated and heightened startle potentiation in anticipation of unpredictable threat, respectively. All results remained significant after controlling for the other symptom dimensions. The present study provides initial evidence that anxiety and depression symptom dimensions demonstrate unique associations with the startle reflex in anticipation of unpredictable threat in children and adolescents.

  4. Anxiety and Depression Symptom Dimensions Demonstrate Unique Relationships with the Startle Reflex in Anticipation of Unpredictable Threat in 8 to 14 Year-Old Girls

    Science.gov (United States)

    Nelson, Brady D.; Hajcak, Greg

    2016-01-01

    There is growing evidence that heightened sensitivity to unpredictability is a core mechanism of anxiety disorders. In adults, multiple anxiety disorders have been associated with a heightened startle reflex in anticipation of unpredictable threat. Child and adolescent anxiety has been linked to an increased startle reflex across baseline, safety, and threat conditions. However, it is unclear whether anxiety in youth is related to the startle reflex as a function of threat predictability. In a sample of 90 8 to 14 year-old girls, the present study examined the association between anxiety symptom dimensions and startle potentiation during a no, predictable, and unpredictable threat task. Depression symptom dimensions were also examined given their high comorbidity with anxiety and mixed relationship with the startle reflex and sensitivity to unpredictability. To assess current symptoms, participants completed the self-report Screen for Child Anxiety Related Emotional Disorders and Children’s Depression Inventory. Results indicated that social phobia symptoms were associated with heightened startle potentiation in anticipation of unpredictable threat and attenuated startle potentiation in anticipation of predictable threat. Negative mood and negative self-esteem symptoms were associated with attenuated and heightened startle potentiation in anticipation of unpredictable threat, respectively. All results remained significant after controlling for the other symptom dimensions. The present study provides initial evidence that anxiety and depression symptom dimensions demonstrate unique associations with the startle reflex in anticipation of unpredictable threat in children and adolescents. PMID:27224989

  5. Primitive reflexes and cognitive function Reflexos primitivos e função cognitiva

    Directory of Open Access Journals (Sweden)

    Alfredo Damasceno

    2005-09-01

    Full Text Available BACKGROUND: Data on the prevalence of primitive reflexes (PR in adulthood, their pathological significance and relationship to age and cognition are controversial. OBJECTIVE: To study the relationship between PR and cognition in 30 patients with probable Alzheimer's disease (AD and 154 control subjects. METHOD: Diagnosis of probable AD was based on DSM-IV, NINCDS-ADRDA, and CAMDEX criteria. Primitive reflexes were quantified from zero (absent to 1 (mild or 2 (markedly present. The Cognitive Abilities Screening Instrument - Short Form (CASI-S was used to evaluate registration, temporal orientation, verbal fluency and recall. A drawing test was added. RESULTS: Most frequent PR among demented and controls were suck (77% and 62%, respectively and snout (60% and 27%, followed by glabellar (30% and 19%, paratonia (37% and 5%, and palmomental (23% and 5%. None of controls had more than three PR. Frequency of PR tended to increase with age and cognitive deterioration. Grasp and Babinski responses were found only in dementia patients. Primitive reflexes were not correlated with each other, except snout with suck, and snout with glabellar reflex. CONCLUSION: The finding of grasp and Babinski sign, or the presence of more than three primitive signs, particularly the combination of paratonia, snout, suck, and palmomental reflexes strongly suggests brain dysfunction, especially when these signs are marked and accompanied by deficits in orientation, recall, verbal fluency, and constructional praxis.CONTEXTO: A prevalência e significado patológico dos reflexos primitivos (RP no adulto, bem como sua relação com a idade e a cognição, são questões controversas. OBJETIVO: Estudar a relação entre RP e cognição em 30 pacientes com doença de Alzheimer (DA e 154 sujeitos controles normais. MÉTODO: O diagnóstico de DA baseou-se nos critérios DSM-IV, NINCDS-ADRDA e CAMDEX. Os RP foram quantificados de 0 (ausente a 1 (leve ou 2 (acentuado. CASI

  6. Effects of short term water immersion on peripheral reflex excitability in hemiplegic and healthy individuals: A preliminary study.

    Science.gov (United States)

    Cronin, N J; Valtonen, A M; Waller, B; Pöyhönen, T; Avela, J

    2016-03-01

    Reflex excitability is increased in hemiplegic patients compared to healthy controls. One challenge of stroke rehabilitation is to decrease the effects of hyperreflexia, which may be possible with water immersion. Methods/Aims: The present study examined the effects of acute water immersion on electrically-evoked Hmax:Mmax ratios (a measure of reflex excitability) in 7 hyperreflexive hemiplegic patients and 7 age-matched healthy people. Hmax:Mmax ratios were measured from soleus on dry land (L1), immediately after (W1) and 5 minutes after immersion (W5), and again after five minutes on land (L5). Water immersion led to an acute increase in Hmax:Mmax ratio in both groups. However, after returning to dry land, there was a non-significant decrease in the Hmax:Mmax ratio of 8% in the hemiplegic group and 10% in healthy controls compared to pre-immersion values. A short period of water immersion can decrease peripheral reflex excitability after returning to dry land in both healthy controls and post-stroke patients, although longer immersion periods may be required for sustainable effects. Water immersion may offer promise as a low-risk, non-invasive and non-pharmaceutical method of decreasing hyperreflexivity, and could thus support aquatic rehabilitation following stroke.

  7. Acoustic startle reflex and pre-pulse inhibition in tinnitus patients

    Institute of Scientific and Technical Information of China (English)

    Kelly Shadwick; Wei Sun

    2014-01-01

    Gap induced pre-pulse inhibition (Gap-PPI) of acoustic startle reflex has been used as a measurement of tinnitus in animal models. However, whether this test is sensitive to detect tinnitus in humans is still unclear. Based on the testing procedure used in animal studies, a human subject testing method was formulated and conducted to investigate if a similar result could be found in tinnitus patients. Audiologic and tinnitus assessments and acoustic startle reflex measurements were performed on seven tinnitus subjects and nine age matched subjects without tinnitus. There was no significant difference found between the control and tinnitus group on the Gap-PPI across the frequencies evaluated. The amplitude of the startle response in the tinnitus group with normal hearing thresholds was significantly higher than the control group and those with tinnitus and hearing loss. This preliminary result suggests that hyperexcitability in the central auditory system may be involved in tinnitus. There was no correlation between hearing thresholds and the increased amplitude of startle response.

  8. Delayed latency of peroneal reflex to sudden inversion with ankle taping or bracing.

    Science.gov (United States)

    Shima, N; Maeda, A; Hirohashi, K

    2005-01-01

    The purpose of the present study was to examine the effects of ankle taping and bracing based on the peroneal reflex in the hypermobile and normal ankle joints with and without history of ankle injury. Thirty-six ankle joints of 18 collegiate American football athletes with and without previous history of injury were studied. The angle of talar tilt (TT) was measured by stress radiograph for classifying normal (TT5 degrees ) ankles. They were tested with taping, bracing, and without any supports as a control. The latency of peroneus longus muscle was measured by a sudden inversion of 25 degrees using surface EMG signals. The results of the present study show no significant three-way Group (hypermobile or normal ankles) by History (previously injured or uninjured ankles) by Condition (control, taping, or bracing) interaction, while Condition main effect was significant (p0.05). In conclusion, ankle taping and bracing delayed the peroneal reflex latency not only for hypermobile ankles and/or injured ankle joints but also for intact ankle joints.

  9. Teacher education and the challenges of the reflexive practice

    Directory of Open Access Journals (Sweden)

    Maria Regina Peres

    2013-06-01

    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.

  10. 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

    1996-01-01

    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)

  11. [Spasm of the near reflex. Treatment with botulinum toxin].

    Science.gov (United States)

    Merino, P; Rojas, P; Gómez de Liaño, P; Franco Iglesias, G

    2015-05-01

    A 38-year old female with diplopia and esotropia, with limitation of ocular abduction in both eyes, with full abduction after doll's head rotation also being observed. She was diagnosed with spasm of the near reflex. Treatment with injections of botulinum toxin in both medial rectus has temporally resolved the convergence spasm. Near reflex spasm is characterized as miosis, pseudomyopia, and convergent strabismus that lead to diplopia, blurred vision, headache, and variable, progressive, and intermittent esotropia. As the spasm worsens there will be limited ocular versions and ductions simulating a sixth nerve palsy. Botulinum toxin may be effective in some cases. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Celina Carter MN

    2014-02-01

    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. Creating safety by strengthening clinicians' capacity for reflexivity

    Science.gov (United States)

    2011-01-01

    This commentary explores the nature of creating safety in the here-and-now. Creating safety encompasses two dimensions: revisiting specific behaviours by focusing on substandard performance (reflection), and a more broad-ranging attention to everyday behaviours that are taken as given (reflexivity). The piece pays particular attention to this second dimension of creating safety. Two techniques that promote reflexivity are discussed: video-filming real-time, everyday clinical practice and inviting clinicians' feedback about their own footage, and reflecting on the knowledge and questions that patients and families have about their care, and about unexpected outcomes and clinical incidents. The piece concludes that feedback about everyday practice using these methods is critical to enhancing the safety of everyday activity. PMID:21450780

  14. Review Essay: Grenzgänger Seeks Reflexive Methodology

    Directory of Open Access Journals (Sweden)

    Wolff-Michael Roth

    2002-09-01

    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

  15. Cortical tremor: a variant of cortical reflex myoclonus.

    Science.gov (United States)

    Ikeda, A; Kakigi, R; Funai, N; Neshige, R; Kuroda, Y; Shibasaki, H

    1990-10-01

    Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.

  16. Comparison of cough reflex test against instrumental assessment of aspiration.

    Science.gov (United States)

    Miles, Anna; Moore, Sara; McFarlane, Mary; Lee, Fiona; Allen, Jacqueline; Huckabee, Maggie-Lee

    2013-06-13

    Silent aspiration is associated with pneumonia and mortality, and is poorly identified by traditional clinical swallowing evaluation (CSE). The aim of this study was to validate cough reflex testing (CRT) for identification of silent aspiration against aspiration confirmed by instrumental assessment. Cough reflex threshold testing was completed on all patients using inhaled, nebulised citric acid. Within an hour, 80 patients underwent videofluoroscopic study of swallowing (VFSS) and 101 patients underwent fibreoptic endoscopic evaluation of swallowing (FEES). All tests were recorded and analysed by two researchers blinded to the result of the alternate test. Significant associations between CRT result and cough response to aspiration on VFSS (X(2) (2)=11.046, p=.003) and FEES (X(2) (2)=34.079, pacid provide a better predictive measure of silent aspiration. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Smolt physiology and endocrinology

    Science.gov (United States)

    McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

    2013-01-01

    Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

  18. Peripheral δ-opioid receptors attenuate the exercise pressor reflex.

    Science.gov (United States)

    Leal, Anna K; Yamauchi, Katsuya; Kim, Joyce; Ruiz-Velasco, Victor; Kaufman, Marc P

    2013-10-15

    In rats with ligated femoral arteries, the exercise pressor reflex is exaggerated, an effect that is attenuated by stimulation of peripheral μ-opioid receptors on group IV metabosensitive afferents. In contrast, δ-opioid receptors are expressed mostly on group III mechanosensitive afferents, a finding that prompted us to determine whether stimulation of these opioid receptors could also attenuate the exaggerated exercise pressor reflex in "ligated" rats. We found femoral arterial injection of [D-Pen2,D-Pen5]enkephalin (DPDPE; 1.0 μg), a δ-opioid agonist, significantly attenuated the pressor and cardioaccelerator components of the exercise pressor reflex evoked by hindlimb muscle contraction in both rats with ligated and patent femoral arteries. DPDPE significantly decreased the pressor responses to muscle mechanoreflex activation, evoked by tendon stretch, in ligated rats only. DPDPE (1.0 μg) had no effect in either group on the pressor and cardioaccelerator responses to capsaicin (0.2 μg), which primarily stimulates group IV afferents. DPDPE (1.0 μg) had no effect on the pressor and cardioaccelerator responses to lactic acid (24 mM), which stimulates group III and IV afferents, in rats with patent femoral arteries but significantly decreased the pressor response in ligated rats. Western blots revealed the amount of protein comprising the δ-opioid receptor was greater in dorsal root ganglia innervating hindlimbs with ligated femoral arteries than in dorsal root ganglia innervating hindlimbs with patent femoral arteries. Our findings support the hypothesis that stimulation of δ-opioid receptors on group III afferents attenuated the exercise pressor reflex.

  19. Spinal mechanism of micturition reflex inhibition by naftopidil in rats.

    Science.gov (United States)

    Sugaya, Kimio; Nishijima, Saori; Kadekawa, Katsumi; Ashitomi, Katsuhiro; Ueda, Tomoyuki; Yamamoto, Hideyuki

    2014-10-29

    We investigated the spinal mechanism through which naftopidil inhibits the micturition reflex by comparing the effects of noradrenaline and naftopidil in rats. The following were investigated: the influence of oral naftopidil on plasma monoamine and amino acid levels, the distribution of oral 14C-naftopidil, the effects of intravenous (IV) or intrathecal (IT) injection of noradrenaline or naftopidil on isovolumetric bladder contractions, amino acid levels in the lumbosacral spinal cord after IT noradrenaline or naftopidil, and the effects of IT naftopidil and strychnine and/or bicuculline on isovolumetric bladder contractions. Oral naftopidil decreased the plasma adrenaline level, while it increased the serotonin and glycine levels. After oral administration, 14C-naftopidil was detected in the spinal cord and cerebrum, as well as in plasma and the prostate gland. When the bladder volume was below the threshold for isovolumetric reflex contractions, IV (0.1mg) or IT (0.1μg) noradrenaline evoked bladder contractions, but IV (1mg) or IT (0.01-1μg) naftopidil did not. When the bladder volume was above the threshold for isovolumetric reflex contractions, IV or IT noradrenaline transiently abolished bladder contractions. IT noradrenaline decreased the levels of glycine and gamma-aminobutyric acid (GABA) in the lumbosacral cord, while IT naftopidil increased the GABA level. IT strychnine and/or bicuculline blocked the inhibitory effect of IT naftopidil on bladder contractions. Naftopidil inhibits the micturition reflex by blocking α1 receptors, as well as by the activation of serotonergic, glycinergic, and GABAergic neurons in the central nervous system. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Maternal low-protein diet-induced delayed reflex ontogeny is attenuated by moderate physical training during gestation in rats.

    Science.gov (United States)

    Falcão-Tebas, Filippe; Bento-Santos, Adriano; Fidalgo, Marco Antônio; de Almeida, Marcelus Brito; dos Santos, José Antônio; Lopes de Souza, Sandra; Manhães-de-Castro, Raul; Leandro, Carol Góis

    2012-02-01

    We evaluated the effects of moderate- to low-intensity physical training during gestation on reflex ontogeny in neonate rats whose mothers were undernourished. Virgin female Wistar rats were divided into four groups as follows: untrained (NT, n 7); trained (T, n 7); untrained with a low-protein diet (NT+LP, n 7); trained with a low-protein diet (T+LP, n 4). Trained rats were subjected to a protocol of moderate physical training on a treadmill over a period of 4 weeks (5 d/week and 60 min/d, at 65 % of VO₂max). After confirming the pregnancy, the intensity and duration of the exercise were reduced. Low-protein groups were provided with an 8 % casein diet, and controls were provided with a 17 % casein diet. Their respective offspring were evaluated (during the 10th-17th days of postnatal life) in terms of physical feature maturation, somatic growth and reflex ontogeny. Pups born to mothers provided with the low-protein diet during gestation and lactation showed delayed physical feature and reflex maturation and a deficit in somatic growth when compared with controls. However, most of these deficiencies were attenuated in pups of undernourished mothers undergoing training. In conclusion, physical training during gestation attenuates the effects of perinatal undernutrition on some patterns of maturation in the central nervous system during development.

  1. Neurophysiology and Neuroanatomy of Reflexive and Volitional Saccades as Revealed by Lesion Studies with Neurological Patients and Transcranial Magnetic Stimulation (TMS)

    Science.gov (United States)

    Muri, Rene M.; Nyffeler, Thomas

    2008-01-01

    This review discusses the neurophysiology and neuroanatomy of the cortical control of reflexive and volitional saccades in humans. The main focus is on classical lesion studies and studies using the interference method of transcranial magnetic stimulation (TMS). To understand the behavioural function of a region, it is essential to assess…

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

    International Nuclear Information System (INIS)

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

    1986-01-01

    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

  3. Modulation of defensive reflex conditioning in snails by serotonin

    Science.gov (United States)

    Andrianov, Vyatcheslav V.; Bogodvid, Tatiana K.; Deryabina, Irina B.; Golovchenko, Aleksandra N.; Muranova, Lyudmila N.; Tagirova, Roza R.; Vinarskaya, Aliya K.; Gainutdinov, Khalil L.

    2015-01-01

    Highlights Daily injection of serotonin before a training session accelerated defensive reflex conditioning in snails.Daily injection of 5-hydroxytryptophan before a training session in snails with a deficiency of serotonin induced by the “neurotoxic” analog of serotonin 5,7-dihydroxytryptamine, restored the ability of snails to learn.After injection of the “neurotoxic” analogs of serotonin 5,6- and 5,7-dihydroxytryptamine as well as serotonin, depolarization of the membrane and decrease of the threshold potential of premotor interneurons was observed. We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the “neurotoxic” analogs 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 2 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. PMID:26557063

  4. The medial olivocochlear reflex in children during active listening.

    Science.gov (United States)

    Smith, Spencer B; Cone, Barbara

    2015-08-01

    To determine if active listening modulates the strength of the medial olivocochlear (MOC) reflex in children. Click-evoked otoacoustic emissions (CEOAEs) were recorded from the right ear in quiet and in four test conditions: one with contralateral broadband noise (BBN) only, and three with active listening tasks wherein attention was directed to speech embedded in contralateral BBN. Fifteen typically-developing children (ranging in age from 8 to14 years) with normal hearing. CEOAE levels were reduced in every condition with contralateral acoustic stimulus (CAS) when compared to preceding quiet conditions. There was an additional systematic decrease in CEOAE level with increased listening task difficulty, although this effect was very small. These CEOAE level differences were most apparent in the 8-18 ms region after click onset. Active listening may change the strength of the MOC reflex in children, although the effects reported here are very subtle. Further studies are needed to verify that task difficulty modulates the activity of the MOC reflex in children.

  5. Rapid motor learning in the translational vestibulo-ocular reflex

    Science.gov (United States)

    Zhou, Wu; Weldon, Patrick; Tang, Bingfeng; King, W. M.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    Motor learning was induced in the translational vestibulo-ocular reflex (TVOR) when monkeys were repeatedly subjected to a brief (0.5 sec) head translation while they tried to maintain binocular fixation on a visual target for juice rewards. If the target was world-fixed, the initial eye speed of the TVOR gradually increased; if the target was head-fixed, the initial eye speed of the TVOR gradually decreased. The rate of learning acquisition was very rapid, with a time constant of approximately 100 trials, which was equivalent to or=1 d without any reinforcement, indicating induction of long-term synaptic plasticity. Although the learning generalized to targets with different viewing distances and to head translations with different accelerations, it was highly specific for the particular combination of head motion and evoked eye movement associated with the training. For example, it was specific to the modality of the stimulus (translation vs rotation) and the direction of the evoked eye movement in the training. Furthermore, when one eye was aligned with the heading direction so that it remained motionless during training, learning was not expressed in this eye, but only in the other nonaligned eye. These specificities show that the learning sites are neither in the sensory nor the motor limb of the reflex but in the sensory-motor transformation stage of the reflex. The dependence of the learning on both head motion and evoked eye movement suggests that Hebbian learning may be one of the underlying cellular mechanisms.

  6. A reflexive exploration of two qualitative data coding techniques

    Directory of Open Access Journals (Sweden)

    Erik Blair

    2016-01-01

    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

  7. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

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

    Science.gov (United States)

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

    2015-06-01

    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. Sympathetic immune modulation and reflexes are well described, and in the past decade the parasympathetic efferent vagus nerve has been added to this immune-regulation network. This system, designated 'the inflammatory reflex', comprises an afferent arm that senses inflammation and an efferent arm that inhibits innate immune responses. Intervention in this system as an innovative principle is currently being tested in pioneering trials of vagus nerve stimulation using implantable devices to treat IBD. Patients benefit from this treatment, but some of the working mechanisms remain to be established, for instance, treatment is effective despite the vagus nerve not always directly innervating the inflamed tissue. In this Review, we will focus on the direct neuronal regulatory mechanisms of immunity in the intestine, taking into account current advances regarding the innervation of the spleen and lymphoid organs, with a focus on the potential for treatment in IBD and other gastrointestinal pathologies.

  9. Physiology of in vitro culture

    Directory of Open Access Journals (Sweden)

    Maria Jesús Cañal

    2001-01-01

    Full Text Available The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship. enviromental control, tissue culture, micropropagation Keywords: in vitro enviromental, characteristic physiology,

  10. Prepulse inhibition and facilitation of the postauricular reflex, a vestigial remnant of pinna startle.

    Science.gov (United States)

    Hackley, Steven A; Ren, Xi; Underwood, Amy; Valle-Inclán, Fernando

    2017-04-01

    If the postauricular reflex (PAR) is to be used effectively in studies of emotion and attention, its sensitivity to basic modulatory effects such as prepulse inhibition and facilitation must be determined. Two experiments were carried out with healthy young adults to assess the effects of transient and sustained visual prestimuli on the pinna-flexion response to trains of startle probes. In the first experiment, participants passively viewed a small white square. It was displayed from 1,000 ms prior to onset of a train of noise bursts until the end of that train. Relative to no-prepulse control trials, PAR amplitude was inhibited, possibly due to the withdrawal of attentional resources from the auditory modality. In the second experiment, participants performed a visual oddball task in which irrelevant trains of startle probes followed most briefly displayed task stimuli (checkerboards). Prepulse inhibition was observed when a transient stimulus preceded the first probe at a lead time of 100 ms. Amplitude facilitation was observed at longer lead times. In addition to documenting the existence of prepulse inhibition and facilitation, the data suggest that the PAR is not elicited by visual stimuli, that temporal expectancy does not influence its amplitude or latency, and that this vestigial microreflex is resistant to habituation. Results are interpreted in light of a recent theory that the human PAR is a highly degraded pinna startle, in which the reflex arc no longer includes the startle center (nucleus reticularis pontis caudalis). © 2017 Society for Psychophysiological Research.

  11. The capsaicin cough reflex in eczema patients with respiratory symptoms elicited by perfume.

    Science.gov (United States)

    Elberling, Jesper; Dirksen, Asger; Johansen, Jeanne Duus; Mosbech, Holger

    2006-03-01

    Respiratory symptoms elicited by perfume are common in the population but have unclear pathophysiology. Increased capsaicin cough responsiveness has been associated with the symptoms, but it is unknown whether the site of the symptoms in the airways influences this association. The aim of this study was to investigate the association between the site of airway symptoms elicited by perfume and cough responsiveness to bronchial challenge with capsaicin. 21 eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case control study. The participants completed a symptom questionnaire and underwent a bronchial challenge with capsaicin. Lower, but not upper, respiratory symptoms elicited by perfume were associated with increased capsaicin cough responsiveness. Having severe symptoms to perfume (n=11) did not relate to the site of the symptoms in the airways and was not associated with increased capsaicin cough responsiveness. In conclusion, respiratory symptoms elicited by perfume may reflect local hyperreactivity related to defensive reflexes in the airways, and measurements of the capsaicin cough reflex are relevant when patients with lower respiratory symptoms related to environmental perfume exposures are investigated.

  12. Human Physiology in an Aquatic Environment.

    Science.gov (United States)

    Pendergast, David R; Moon, Richard E; Krasney, John J; Held, Heather E; Zamparo, Paola

    2015-09-20

    Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system. Copyright © 2015 John Wiley & Sons, Inc.

  13. Acoustic Reflex Screening of Conductive Hearing Loss for Third Window Disorders.

    Science.gov (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

    2016-02-01

    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.

  14. Correlation of augmented startle reflex with brainstem electrophysiological responses in Tay-Sachs disease.

    Science.gov (United States)

    Nakamura, Sadao; Saito, Yoshiaki; Ishiyama, Akihiko; Sugai, Kenji; Iso, Takashi; Inagaki, Masumi; Sasaki, Masayuki

    2015-01-01

    To clarify the evolution of an augmented startle reflex in Tay-Sachs disease and compare the temporal relationship between this reflex and brainstem evoked potentials. Clinical and electrophysiological data from 3 patients with Tay-Sachs disease were retrospectively collected. The augmented startle reflex appeared between the age of 3 and 17 months and disappeared between the age of 4 and 6 years. Analysis of brainstem auditory evoked potentials revealed that poor segregation of peak I, but not peak III, coincided with the disappearance of the augmented startle reflex. A blink reflex with markedly high amplitude was observed in a patient with an augmented startle reflex. The correlation between the augmented startle reflex and the preservation of peak I but not peak III supports the theory that the superior olivary nucleus is dispensable for this reflex. The blink reflex with high amplitudes may represent augmented excitability of reticular formation at the pontine tegmentum in Tay-Sachs disease, where the pattern generators for the augmented startle and blink reflexes may functionally overlap. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  15. [From reflex arc to psychic apparatus: neurology and psychoanalysis around 1900].

    Science.gov (United States)

    Porath, Erik

    2009-03-01

    As a disciple of Ernst Wilhelm von Brücke and Theodor Meynert, Sigmund Freud was familiar with 19th century physiology and neurology. He started his career with laboratory work and began later on, when being a young medic to develop an explicit psychological method for curating hysterics. These cases of hysteria ask riddles to the established medical discourse and practice. Freud's long time unpublished Entwurf einer Psychologie (1895) makes the attempt of a "psychology for the neurologist". He tried to give a sufficient theory of the psychic apparatus on the basis of natural science. At the same time he (together with Josef Breuer) published his Studies on Hysteria, which--in addition to his earlier essay on Aphasia (1891)--argued, that there is no clear cut relation between body and soul. Despite the dubious, non-reductive character of the soma-psyche-relation, Freud gave reason to search for a complex field of interrelations between the physiological and psychological knowledge, beyond the divide of natural sciences and humanities. Not until his groundbreaking Traumdeutung (1900) Freud gave up the claim of reintegrating psychological knowledge into the neuroscientific field for now. But up to his latest work he always adheres to the principal project of unifying the natural and the psychical being of the subject. In the gap between the two spheres, for long occupied by the discursive figure of the 'psycho-physical parallelism', Freud situated the Unconscious. In the passage to a psychoanalytical theory of psychic events Freud took up the model of the reflex arc well known from neurology. The transmission into psychoanalysis complexifies the unilinearity of reflexes, so that the psychic apparatus can be analysed as a cybernetic mechanism 'avant la lettre'. It is interesting enough that inhibition as well as consciousness play a key role in the regulation of the psychic apparatus. In this context Freud stresses the importance of speech and language within the

  16. Desensitization of the cough reflex by exercise and voluntary isocapnic hyperpnea.

    Science.gov (United States)

    Lavorini, Federico; Fontana, Giovanni A; Chellini, Elisa; Magni, Chiara; Duranti, Roberto; Widdicombe, John

    2010-05-01

    Little is known about the effects of exercise on the sensory and cognitive aspects of coughing evoked by inhalation of tussigenic agents. The threshold for the cough reflex induced by inhalation of increasing nebulizer outputs of ultrasonically nebulized distilled water (fog), an index of cough reflex sensitivity, was assessed in twelve healthy humans in control conditions, during exercise and during voluntary isocapnic hyperpnea (VIH) at the same ventilatory level as the exercise. The intensity of the urge to cough (UTC), a cognitive component of coughing, was recorded throughout the trials on a linear scale. The relationships between inhaled fog nebulizer outputs and the correspondingly evoked UTC values, an index of the perceptual magnitude of the UTC sensitivity, were also calculated. Cough appearance was always assessed audiovisually. At an exercise level of 80% of anaerobic threshold, the median cough threshold was increased from a control value of 0.73 to 2.22 ml/min (PVIH, the threshold increased from 0.73 to 2.22 ml/min (PVIH compared with control, mean UTC values at cough threshold were unchanged, i.e., control, 3.83 cm; exercise, 3.12 cm; VIH, 4.08 cm. The relationship of the fog nebulizer output/UTC value was linear in control conditions and logarithmic during both exercise and VIH. The perception of the magnitude of the UTC seems to be influenced by signals or sensations arising from exercising limb and thoracic muscles and/or by higher nervous (cortical) mechanisms. The results indicate that the adjustments brought into action by exercise-induced or voluntary hyperpnea exert inhibitory influences on the sensory and cognitive components of fog-induced cough.

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

    OpenAIRE

    Christian Iber

    2017-01-01

    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 d...

  18. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  19. Effect of straining on diaphragmatic crura with identification of the straining-crural reflex. The "reflex theory" in gastroesophageal competence

    Directory of Open Access Journals (Sweden)

    El Sibai Olfat

    2004-09-01

    Full Text Available Abstract Background The role of the crural diaphragm during increased intra-abdominal pressure is not exactly known. We investigated the hypothesis that the crural diaphragm undergoes reflex phasic contraction on elevation of the intra-abdominal pressure with a resulting increase of the lower esophageal pressure and prevention of gastro-esophageal reflux. Methods The esophageal pressure and crural diaphragm electromyographic responses to straining were recorded in 16 subjects (10 men, 6 women, age 36.6 ± 11.2 SD years during abdominal hernia repair. The electromyogram of crural diaphragm was recorded by needle electrode inserted into the crural diaphragm, and the lower esophageal pressure by a saline-perfused catheter. The study was repeated after crural anesthetization and after crural infiltration with saline. Results The crural diaphragm exhibited resting electromyographic activity which showed a significant increase on sudden (coughing, p Conclusions Straining effected an increase of the electromyographic activity of the crural diaphragm and of the lower esophageal pressure. This effect is suggested to be reflex in nature and to be mediated through the "straining-crural reflex". The crural diaphragm seems to play a role in the lower esophageal competence mechanism. Further studies are required to assess the clinical significance of the current results in gastro-esophageal reflux disease and hiatus hernia.

  20. Effects of biofeedback on obstructive defecation--reconditioning of the defecation reflex?

    Science.gov (United States)

    Papachrysostomou, M; Smith, A N

    1994-01-01

    Twenty two patients with obstructive defecation were recruited for relaxation training by domiciliary self regulatory biofeedback. Each patient served as his or her own control for anorectal and proctographic assessments. Biofeedback training improved the obstructive symptoms of the patients and showed significant change in various parameters related to the obstructive defecation syndrome. As examined by isotope dynamic proctography: the defecation rate (% of evacuation/defecation time) was significantly increased (p anismus index (p < 0.0001). The rectal sensation was improved (p < 0.05), concomitantly. Biofeedback thus improves the defecation act in patients suffering from inappropriate contraction of the pelvic floor and sphincter musculature. Furthermore, this study has shown that biofeedback objectively influences the defecation reflex leading to an improved quality of higher control of bowel function. PMID:8307478

  1. Effects of increased occlusal vertical dimension on the jaw-opening reflex in adult rats.

    Science.gov (United States)

    Makiguchi, Mio; Funaki, Yukiha; Kato, Chiho; Okihara, Hidemasa; Ishida, Takayoshi; Yabushita, Tadachika; Kokai, Satoshi; Ono, Takashi

    2016-12-01

    Malocclusion with deep overbite and facial esthetics improve when facial height is intentionally increased during orthodontic extrusion of the posterior teeth. Thus, a better understanding of post-treatment stability of increased occlusal vertical dimension (iOVD) in adult patients is important. We focused on the jaw-opening reflex (JOR), which plays an important role in the control of jaw movements during mastication, and investigated the effects of iOVD on the JOR in rats with an electrophysiological technique. One hundred and twenty 13-week-old male Wistar rats were randomly divided into control and experimental groups. Rats in the experimental group received a 2-mm buildup of composite resin on the maxillary molars at 13 weeks of age. The JOR was induced by low-intensity electrical stimulation of the left inferior alveolar nerve. The electromyographic responses were recorded from the digastric muscle at 13, 14, 15, 17, 19, and 23 weeks of age. JOR properties including latency, duration, and peak-to-peak amplitude were measured and compared between the groups. The latency of the JOR was significantly longer and the peak-to-peak amplitude was significantly smaller in the experimental group than in the control group from 14 to 19 weeks of age, while the reflex duration was not significantly different. Intra-group comparisons of the latency and peak-to-peak amplitudes among rats 14-19 weeks of age were significantly different between the experimental group and the control group. iOVD affected the latency and amplitude of the JOR but not the duration. The JOR adapted after 10 weeks of iOVD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Effectiveness of Spiritist "passe" (Spiritual healing) for anxiety levels, depression, pain, muscle tension, well-being, and physiological parameters in cardiovascular inpatients: A randomized controlled trial.

    Science.gov (United States)

    Carneiro, Élida Mara; Barbosa, Luana Pereira; Marson, Jorge Marcelo; Terra, Juverson Alves; Martins, Claudio Jacinto Pereira; Modesto, Danielle; Resende, Luiz Antônio Pertili Rodrigues de; Borges, Maria de Fátima

    2017-02-01

    Biofield therapies, such as laying on of hands, are used in association with Conventional Medicine as Spiritist "passe", among others. The aim of this study was to evaluate anxiety, depression, pain, muscle tension and well-being, as well as physiological parameters in cardiovascular inpatients submitted to the Spiritist "passe", sham, and no intervention. In the total, 41 cardiovascular inpatients submitted to the Spiritist "passe", sham, and no intervention during a 10-min period on 3 consecutive days. They were evaluated through anxiety and depression level, pain, the perceptions of muscle tension and well-being and physiological parameters, before and after interventions. A significant reduction (p=0.001) in anxiety scores and muscle tension (p=0.011), improvement of well-being (p=0.003) and a significant increase in peripheral oxyhemoglobin saturation scores (p=0.028) were observed in Spiritist "passe" patients, and a significant reduction (p=0.028) of muscle tension and improvement of well-being (p=0.045) in sham patients. However, muscle tension reduction (p=0.003) and improvement of well-being (p=0.003) were more accentuated in the Spiritist "passe" compared to sham and no intervention. Results suggest that the Spiritist "passe" appeared to be effective, reducing anxiety level and the perception of muscle tension, consequently improving peripheral oxyhemoglobin saturation and the sensation of well-being compared to sham and no intervention in cardiovascular inpatients. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. What can other animals tell us about human social cognition?An evolutionary perspective on reflective and reflexive processing

    Directory of Open Access Journals (Sweden)

    Erin E Hecht

    2012-07-01

    Full Text Available Human neuroscience has seen a recent boom in studies on reflective, controlled, explicit social cognitive functions like imitation, perspective‐taking, and empathy. The relationship of these higher‐level functions to lower‐level, reflexive, automatic, implicit functions is an area of current research. As the field continues to address this relationship, we suggest that an evolutionary, comparative approach will be useful, even essential. There is a large body of research on reflexive, automatic, implicit processes in animals. A growing perspective sees social cognitive processes as phylogenically continuous, making findings in other species relevant for understanding our own. One of these phylogenically continuous processes appears to be self‐other matching or simulation. Mice are more sensitive to pain after watching other mice experience pain; geese experience heart rate increases when seeing their mate in conflict; and infant macaques, chimpanzees, and humans automatically mimic adult facial expressions. In this article, we review findings in different species that illustrate how such reflexive processes are related to (higher order reflexive processes, such as cognitive empathy, theory of mind, and learning by imitation. We do so in the context of self‐other matching in three different domains – in the motor domain (somatomotor movements, in the perceptual domain (eye movements and cognition about visual perception, and in the autonomic/emotional domain. We also review research on the developmental origin of these processes and their neural bases across species. We highlight gaps in existing knowledge and point out some questions for future research. We conclude that our understanding of the psychological and neural mechanisms of self‐other mapping and other functions in our own species can be informed by considering the layered complexity these functions in other species.

  4. Facilitation of Hoffmann reflexes of ankle muscles in prone but not standing positions by focal ankle-joint cooling.

    Science.gov (United States)

    Kim, Kyung-Min; Ingersoll, Christopher D; Hertel, Jay

    2015-05-01

    Focal ankle-joint cooling (FAJC) has been shown to increase Hoffmann (H) reflex amplitudes of select leg muscles while subjects lie prone, but it is unknown whether the neurophysiological cooling effects persist in standing. To assess the effects of FAJC on H-reflexes of the soleus and fibularis longus during 3 body positions (prone, bipedal, and unipedal stances) in individuals with and without chronic ankle instability (CAI). Crossover. Laboratory. 15 young adults with CAI (9 male, 6 female) and 15 healthy controls. All subjects received both FAJC and sham treatments on separate days in a randomized order. FAJC was accomplished by applying a 1.5-L plastic bag filled with crushed ice to the ankle for 20 min. Sham treatment involved room-temperature candy corn. Maximum amplitudes of H-reflexes and motor (M) waves were recorded while subjects lay prone and then stood in quiet bipedal and unipedal stances before and immediately after each treatment. Primary outcome measures were H(max):M(max) ratios for the soleus and fibularis longus. Three-factor (group × treatment condition × time) repeated-measures ANOVAs and Fisher LSD tests were performed for statistical analyses. Significant interactions of treatment condition by time for prone H(max):M(max) ratios were found in the soleus (P = .001) and fibularis longus (P = .003). In both muscles, prone H(max):M(max) ratios moderately increased after FAJC but not after sham treatment. The CAI and healthy groups responded similarly to FAJC. In contrast, there were no significant interactions or main effects in the bipedal and unipedal stances in either muscle (P > .05). FAJC moderately increased H-reflex amplitudes of the soleus and fibularis longus while subjects were prone but not during bipedal or unipedal standing. These results were not different between groups with and without CAI.

  5. Effect of joint mobilization on the H Reflex amplitude in people with spasticity

    OpenAIRE

    Pérez Parra, Julio Ernesto; Henao Lema, Claudia Patricia

    2011-01-01

    Objective: To determine the effect of ankle joint mobilization on the H reflex amplitude of thesoleus muscle in people with spasticity. Materials and methods: A quasi-experimental study withcrossover design and simple masking was conducted in 24 randomized subjects to initiate thecontrol or experimental group. Traction and rhythmic oscillation were applied for five minutesto the ankle joint. H wave amplitude changes of Hoffmann reflex (electrical equivalent of themonosynaptic spinal reflex) w...

  6. Study of Achilles Tendon Reflex in Normal Korean and Various Thyroid Diseases

    International Nuclear Information System (INIS)

    Kang, Jin Yung; Kim, Kwang Won; Yae, Sung Bo; Lee, Hong Kyu; Koh, Chang Soon

    1975-01-01

    In an attempt to establish the diagnostic value of Achilles tendon reflex and to determine the normal value of Achilles tendon reflex time in normal Korean, the author measured the Achilles tendon reflex time by photomotograph. This study was carried out in 272 cases with various thyroid diseases and 340 normal Korean. 1) The Achilles tendon reflex time in normal Korean was like this, between 11 years old and 20 years old; male (62 cases); 250±27 msec, female (36 cases); 266±27 msec, between 21 years old and 30 years old; male (38 cases); 271±27 msec, female (21 cases); 284±27 msec, between 31 years old and 40 years old; male (26 cases); 275±25 msec, female (29 cases); 291±27 msec, between 41 years old and 50 years old; male (20 cases); 286±35 msec, female (24 cases); 307±42 msec, between 51 years old and 60 years old, male (20 cases); 296±33 msec, female (20 cases); 318±46 msec, over 61 years; male (24 cases) 301±33 msec, female (20 cases); 325±35 msec. The Achilles tendon reflex time was delayed with increasing age and delayed in the female. 2) The Achilles tendon reflex time was markedly shortened to 221±20 msec in untreated hyperthyroidism. 3) The Achilles tendon reflex time was markedly delayed to 435±59 msec in hypothyroidism. 4) The Achilles tendon reflex time was not changed significantly in other thyroid diseases with norms thyroid function. 5) The Achilles tendon reflex time showed good correlationship with ETR, T 3 RU, 131 I thyroid uptake and serum TSH. 6) Reproducibility of Achilles tendon reflex time was good, and no significant difference between left and right was noted. 7) Diagnostic accuracy of Achilles tendon reflex time was 71% in hyperthyroidism and 90% in hypothyroidism. 8) The Achilles tendon reflex time showed useful test to evaluate the clinical course of the hyperthyroidism.

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

    Science.gov (United States)

    Paltani, S.; Ricci, C.

    2017-11-01

    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).

  8. Inhibition of reflex vagal bradycardia by a central action of 5-hydroxytryptophan.

    OpenAIRE

    Tadepalli, A. S.

    1980-01-01

    1 Vagally mediated reflex bradycardia was elicited in spinal cats with intravenous pressor doses of noradrenaline. Administration of 5-hydroxytryptophan (1.5 and 3 mg total dose) into the fourth cerebral ventricle reduced the reflex bradycardia. 2 Inhibition of central amino acid decarboxylase with R044602 prevented the effects of 5-hydroxytryptophan. After intravenous administration of 5-hydroxytryptophan, vagal reflex bradycardia was not affected. 3 Results suggest that 5-hydroxytryptophan ...

  9. The physiology of blood loss and shock: New insights from a human laboratory model of hemorrhage.

    Science.gov (United States)

    Schiller, Alicia M; Howard, Jeffrey T; Convertino, Victor A

    2017-04-01

    The ability to quickly diagnose hemorrhagic shock is critical for favorable patient outcomes. Therefore, it is important to understand the time course and involvement of the various physiological mechanisms that are active during volume loss and that have the ability to stave off hemodynamic collapse. This review provides new insights about the physiology that underlies blood loss and shock in humans through the development of a simulated model of hemorrhage using lower body negative pressure. In this review, we present controlled experimental results through utilization of the lower body negative pressure human hemorrhage model that provide novel insights on the integration of physiological mechanisms critical to the compensation for volume loss. We provide data obtained from more than 250 human experiments to classify human subjects into two distinct groups: those who have a high tolerance and can compensate well for reduced central blood volume (e.g. hemorrhage) and those with low tolerance with poor capacity to compensate.We include the conceptual introduction of arterial pressure and cerebral blood flow oscillations, reflex-mediated autonomic and neuroendocrine responses, and respiration that function to protect adequate tissue oxygenation through adjustments in cardiac output and peripheral vascular resistance. Finally, unique time course data are presented that describe mechanistic events associated with the rapid onset of hemodynamic failure (i.e. decompensatory shock). Impact Statement Hemorrhage is the leading cause of death in both civilian and military trauma. The work submitted in this review is important because it advances the understanding of mechanisms that contribute to the total integrated physiological compensations for inadequate tissue oxygenation (i.e. shock) that arise from hemorrhage. Unlike an animal model, we introduce the utilization of lower body negative pressure as a noninvasive model that allows for the study of progressive

  10. Reflexivity: The Creation of Liminal Spaces--Researchers, Participants, and Research Encounters.

    Science.gov (United States)

    Enosh, Guy; Ben-Ari, Adital

    2016-03-01

    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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... 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......-reflex amplitude during walking was affected by aging, and changes during the swing phase could be seen in the middle-aged subjects. Subdividing the 2 age groups into groups of facilitated or suppressed swing-phase H-reflex revealed that the H-reflex amplitude modulation pattern in the group with facilitated swing...

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

    Science.gov (United States)

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

    2013-11-01

    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.

  13. Dynamics of a stabilized motor defense conditioned reflex at different levels of motivation in irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Shtemberg, A S

    1982-05-01

    Postradiation dynamics of strengthened motor-defense conditioned reflex in rats-males irradiated with the doses of 94.111 and 137 Gy was studied. Phase disturbances of conditioned-reflex activity increased with enhancing irradiation dose have been revealed. Rapid recovery of conditioned reflex after short primary aggravation was a characteristic peculiarity. At that, the dynamics of relation of main nervous processes in cortex was noted for significant instability increasing with radiation syndrome development. Enhancement of force of electro-defense support promoted more effective strengthening of temporary connections and conditioned high stability of trained-reflex reactions during serious functional disturbances resulted from sublethal dose irradiation.

  14. Modification of Otolith Reflex Asymmetries Following Space Flight

    Science.gov (United States)

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

    2011-01-01

    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.

  15. Effortful control as predictor of adolescents' psychological and physiological responses to a social stress test : The Tracking Adolescents' Individual Lives Survey

    NARCIS (Netherlands)

    Oldehinkel, Albertine J.; Hartman, Catharina A.; Nederhof, Esther; Riese, Harriette; Ormel, Johan

    Effortful control is thought to foster adaptive action in defensive contexts and may thereby protect individuals against anxious inhibition and focus on their own distress. We examined if effortful control predicted adolescents' perceived arousal, unpleasantness, and control as well as autonomic

  16. Reproduction, physiology and biochemistry

    Science.gov (United States)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  17. Endogenous Pyrogen Physiology.

    Science.gov (United States)

    Beisel, William R.

    1980-01-01

    Discusses the physiology of endogenous pyrogen (EP), the fever-producing factor of cellular origin. Included are: its hormone-like role, its molecular nature, bioassay procedures, cellular production and mechanisms of EP action. (SA)

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

    DEFF Research Database (Denmark)

    Emmeche, Claus

    2015-01-01

    scaffolding is a multi-level phenomenon. Focusing upon levels of semiosis specific to humans, the formation of the personal self and the role of friendship and similar interpersonal relations in this process is explored through Aristotle’s classical idea of the friend as ‘another self’, and sociologist...... 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...

  19. Reflexive reasoning for distributed real-time systems

    Science.gov (United States)

    Goldstein, David

    1994-01-01

    This paper discusses the implementation and use of reflexive reasoning in real-time, distributed knowledge-based applications. Recently there has been a great deal of interest in agent-oriented systems. Implementing such systems implies a mechanism for sharing knowledge, goals and other state information among the agents. Our techniques facilitate an agent examining both state information about other agents and the parameters of the knowledge-based system shell implementing its reasoning algorithms. The shell implementing the reasoning is the Distributed Artificial Intelligence Toolkit, which is a derivative of CLIPS.

  20. Habituation of the orienting reflex and the development of Preliminary Process Theory.

    Science.gov (United States)

    Barry, Robert J

    2009-09-01

    The orienting reflex (OR), elicited by an innocuous stimulus, can be regarded as a model of the organism's interaction with its environment, and has been described as the unit of attentional processing. A major determinant of the OR is the novelty of the eliciting stimulus, generally operationalized in terms of its reduction with stimulus repetition, the effects of which are commonly described in habituation terms. This paper provides an overview of a research programme, spanning more than 30 years, investigating psychophysiological aspects of the OR in humans. The major complication in this research is that the numerous physiological measures used as dependent variables in the OR context fail to jointly covary with stimulus parameters. This has led to the development of the Preliminary Process Theory (PPT) of the OR to accommodate the complexity of the observed stimulus-response patterns. PPT is largely grounded in autonomic measures, and current work is attempting to integrate electroencephalographic measures, particularly components in the event-related brain potentials reflecting aspects of stimulus processing. The emphasis in the current presentation is on the use of the defining criteria of the habituation phenomenon, and Groves and Thompson's Dual-process Theory, in the development of PPT.