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Impaired Heart Rate Regulation and Depression of Cardiac Chronotropic and Dromotropic Function in Polymicrobial SepsisHoover, Donald B., Ozment, Tammy R., Wondergem, Robert, Li, Chuanfu, Williams, David L. 01 January 2015 (has links)
The scope of cardiac pathophysiology in sepsis has not been fully defined. Accordingly, we evaluated the effects of sepsis on heart rate (HR), HR variability, and conduction parameters in a murine model of sepsis. Electrocardiograms were recorded noninvasively from conscious mice before and after cecal ligation and puncture (CLP) or sham surgery. Responses of isolated atria to tyramine and isoproterenol were quantified to assess the functional state of sympathetic nerves and postjunctional sensitivity to adrenergic stimulation. Cecal ligation and puncture mice had lower HR compared with sham at 16 to 18 h postsurgery (sham, 741 ± 7 beats/min; CLP, 557 ± 31 beats/min; n = 6/group; P < 0.001), and there was significant prolongation of the PR, QRS, and QTc intervals. Slowing of HR and conduction developed within 4 to 6 h after CLP and were preceded by a decrease in HR variability. Treatment of CLP mice with isoproterenol (5 mg/kg, intraperitoneally) at 25 h after surgery failed to increase HR or decrease conduction intervals. The lack of in vivo response to isoproterenol cannot be attributed to hypothermia because robust chronotropic and inotropic responses to isoproterenol were evoked from isolated atria at 25°C and 30°C. These findings demonstrate that impaired regulation of HR (i.e., reduced HR variability) develops before the onset of overt cardiac rate and conduction changes in septic mice. Subsequent time-dependent decreases in HR and cardiac conduction can be attributed to hypothermia and would contribute to decreased cardiac output and organ perfusion. Because isolated atria from septic mice showed normal responsiveness to adrenergic stimulation, we conclude that impaired effectiveness of isoproterenol in vivo can be attributed to reversible effects of systemic factors on adrenergic receptors and/or postreceptor signaling.
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Examining Generalized Anxiety Disorder During Social Interactions: Cardiac Activity, and the Influence of AffectPiedmont, Joanna I. January 2015 (has links)
No description available.
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The effect of musical tempo on subjective and physiological indices of affective responseEllis, Robert J. 28 September 2009 (has links)
No description available.
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Providing Cadence Feedback In Real-Time To Guide Cardiovascular WorkoutsRash, Levi O 01 June 2024 (has links) (PDF)
Cardiovascular workouts offer numerous health benefits, yet beginners often find it challenging to initiate them. Existing wearable technologies, although providing valuable feedback such as heart rate zones, often disrupt the workout flow and distract users due to the need for interaction with the wearable display. In response, we propose an alternative feedback mechanism: cadence, measured in steps per minute. This feedback mechanism uses multiplicative control to produce the correct cadence for the user’s target heart rate (HR). To model the HR and cadence relationship, a first-order system was used. The prototype implementation of this system was completed in Arduino, using a force sensitive resistor (FSR) to measure the user’s cadence and a POLAR HR strap to measure the user’s HR. The cadence is updated every 10 seconds to allow the user to sync to the cadence metronome provided by earbuds. This proposed system has shown promising experimental results for both moderate-intensity and high-intensity workouts, skipping the transition zone between them. This allows the user to avoid awkward workout intensities between a fast walk and a jog.
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Autism Spectrum Disorder Traits and Parental Stress: The moderating role of parental self-efficacyFactor, Reina 17 November 2016 (has links)
Previous research has established that caregivers of children with Autism Spectrum Disorder (ASD) experience greater levels of parenting stress as a result of unique parenting demands and child problem behavior (Davis & Carter, 2008; Estes et al., 2013). Positive self-concepts, specifically parental self-efficacy (PSE), have been implicated as a buffer to stress in a number of contexts (Cieslak, Benight, & Lehman, 2008). While many studies examine parenting stress in relation to ASD, they often use parent self-report rather than objective measures in a laboratory setting. The present study aimed to further explore the role of PSE in the relationship of parental stress and ASD traits through a biological measure of stress, as well as a parent self-report within a controlled laboratory environment.
Forty-two mother and child dyads participated in a validated parent-child interaction task designed to elicit a stressful experience. Mother’s heart rate (HR) and heart rate variability (HRV) were monitored as the physiological measure of stress reactivity. Mothers also self-reported on ASD traits, perceived stress-reactivity, and PSE. Results demonstrated a significant positive main effect for ASD traits on HRV reactivity, and an interaction such that the relationship between ASD traits and HRV reactivity (i.e., more emotional flexibility) was stronger in those with lower PSE. Given the low sample size and subsequent low power, results should be viewed with caution. Considerations of the context of HRV as well as implications for treatment targets and studying parental stress are explored. / Master of Science
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Remote heart rate estimation by evaluating measurements from multiple signals / Pulsmätning på avstånd genom viktning av mätvärden från olika signalerUggla Lingvall, Kristoffer January 2017 (has links)
Heart rate can say a lot about a person's health. While most conventional methods for heart rate measurement require contact with the subject, these are not always applicable. In this thesis, a non-invasive method for pulse detection is implemented and analyzed. Different signals from the color of the forehead—including the green channel, the hue channel and different ICA and PCA components—are inspected, and their resulted heart rates are weighted together according to the significance of their FFT peaks. The system is tested on videos with different difficulties regarding the amount of movement and setting of the scene. The results show that the approach of weighting measurements from different signals together has great potential. The system in this thesis, however, does not perform very well on videos with a lot of movement because of motion noise. Though, with better, less noisy signals, good results can be expected. / En människas puls säger en hel del om dennes hälsa. För att mäta pulsenanvänds vanligtvis metoder som vidrör människan, vilket iblandär en nackdel. I det här examensarbetet tas en metod för pulsmätningpå avstånd fram, som endast använder klipp från en vanlig videokamera. Färgen i pannan mäts och utifrån den genereras flera signalersom analyseras, vilket resulterar i olika mätvärden för pulsen. Genomatt värdera dessa mätvärden med avseende på hur tydliga signalernaär, beräknas ett viktat medelvärde som ett slutgiltigt estimat på medelpulsen. Metoden testas på videoklipp med varierande svårighetsgrad,beroende på hur mycket rörelser som förekommer och på vilketavstånd från kameran försökspersonen står. Resultaten visar att metodenhar mycket god potential och att man kan man förvänta sig finaresultat med bättre, mindre brusiga signaler.
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INFLUENCE OF THE SEROTONERGIC SYSTEM ON PHYSIOLOGY, DEVELOPMENT, AND BEHAVIOR OF DROSOPHILA MELANOGASTERDasari, Sameera 01 January 2007 (has links)
The regulation and modulation of the serotonergic system is clinically significant in humans. Abnormally low levels of serotonin can result in depression and conditions like panic disorder, obsessive-compulsive disorder, social anxiety disorder, sudden infant death syndrome, and eating disorders. The mechanistic role of serotonin (5-HT) on the neural circuits related with these diseases is not definitively known. Drosophila is a simple model system that provides an advantage over vertebrates to modify genetically and for electrophysiological studies on identifiable cells. In this organism the sensory-CNS-motor circuit is modulated by 5-HT, octopamine (OA), and dopamine (DA), which gives one insight that these neuromodulators are playing a role in central neuronal circuits. The role of 5-HT in the behavior and development of Drosophila melanogaster larvae is being studied. p-CPA (para-chlorophenylalanine) blocks the synthesis of 5-HT by inhibiting tryptophan hydroxylase. The development, behavior and physiology in 3rd instar larvae are affected after feeding this drug. MDMA (3,4 methylenedioxyamphetamine), an analog of methamphetamine is a drug of abuse that has been shown to cause depletion of 5-HT from nerve terminals. It causes the 5-HT transporter to work in reverse. Thus, a dumping of 5-HT results. In Drosophila 3rd instar larva development, physiology and behavior are effected when MDMA is fed throughout their development period. Also at the fly neuromuscular junction, (NMJ) MDMA is causing more evoked vesicular release of glutamate from the presynaptic nerve terminal. Also using anti-sense expression of the 5-HT2dro receptor, role of 5-HT and one of its receptors is studied on development, physiology and behavior. Knock down of 5-HT2dro resulted in developmental delay. Physiology and behavior were also abnormal in these animals.
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Orthostatic blood pressure and heart rate responses within hypovolemic and normovolemic populations.Patterson, Fran Dolores. January 1994 (has links)
A descriptive study was conducted comparing the blood pressure and heart rate responses to position change among hypovolemic and normovolemic subjects. A convenience sample of 32 men and women from an emergency room with complaints of diarrhea, vomiting, vaginal or rectal bleeding for $\ge$12 hours duration were recruited. The normovolemic group consisted of a convenience sample of 30 men and women from the community. Data analysis included a mixed design analysis of variance. Compared to supine baseline measurements, between group changes in the systolic, diastolic, and mean arterial blood pressure were not statistically significant (p $>$.05). Once the subject stood, heart rate increased statistically significant in both groups (p $<$.05). The data suggest orthostatic hypotension can be considered when the supine resting heart rate is $\ge$87 beats per minute, and if upon standing, heart rate increases by $\ge$19.33 or is $\ge$110 beats per minute. Heart rate measurements should be taken at one minute after standing.
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Anxiety and Differences in Physiological Responding to Ambiguous Situational Vignettes in AdolescentsBanks, Donice M 16 December 2016 (has links)
Research has documented a tendency among youth to have biased interpretations of ambiguous information. For example, anxious youth are more likely to interpret ambiguous situations as negative or threatening (e.g., Cannon & Weems, 2010). Similarly, when interpreting social cues, aggressive youth exhibit hostile attribution biases more often than non-aggressive youth in response to ambiguous situations (e.g., Crick & Dodge, 1996). Research suggests that youth with anxiety and aggression exhibit differential physiological reactivity in response to threat. However, research has yet to examine the linkages amongst physiological reactivity to ambiguous situations, anxiety, and aggression in adolescents. The current study had several interrelated aims. Youths’ physiological responding (i.e., heart rate and skin conductance) to a series of animated vignettes depicting ambiguous social situations was examined. Anxiety, aggression, and hostile attributional bias (HAB) were also tested as predictors of differential physiological responding to the vignettes, as well as the interrelations between anxiety and HAB and aggression and HAB.
Eighty youth completed a physiological assessment in which they viewed a series of hypothetical situational vignettes while their heart rate and skin conductance were measured. Participants also completed questionnaires measuring symptoms of anxiety, aggression, and HAB. Results indicated that there was differential physiological responding to the vignettes such that participants’ heart rates showed a pattern of deceleration followed by acceleration across time. Physiological responses were predicted by HAB such that those with high HAB had higher heart rates and exhibited more pronounced deceleration and acceleration across time than those with low HAB. There was support for anxiety as a significant predictor of responses among those participants with higher levels of HAB such that heart rates remained elevated with very little deceleration across time, suggesting a pattern of physiological hyperarousal and blunted reactivity. However, aggression did not predict differential physiological responding to the ambiguous vignettes, nor did HAB moderate the association between aggression and physiological responding. These findings add to the literature by contributing to knowledge about physiological responding to ambiguous situations and associations between this link with anxiety, aggression, and HAB.
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Kondiční příprava florbalového brankáře / Floorball goalkeeper conditioningKoráb, Jakub January 2012 (has links)
The title of the work: Floorball goalkeeper conditioning The aim of the work: Based on the identified needs for floorball goalkeeper conditioning the diploma thesis deals with composing the manual for stimulating their specific demands. Methodology: The essentials of the work are both foreign and Czech literature searches dealing with the given issue, measuring functional ability with a sporttester and maximum heart rate laboratory measurement. Based on floorball goalkeeping functional requirements two main areas of stimulation have been defined - speed and speed endurance. The work has been consulted with the renowned conditioning trainers - namely e.g. Josef Bruk (ice hockey goaltending), PhDr. Aleš Kaplan (basketball, football, athletics) and PaeDr. Miroslav Špalek (football goalkeeping, tennis). Outcomes: Measured values of heart rate during floorball goalkeeping performance have reached over 70 % of goalkeepers' maximum heart rate. The measured data show high demands on conditioning component of floorball goalkeeping and the need for its continuous improvement for better performance. As with growing heart rate combine some negative impacts on performance - tiredness and concentration problems. It is possible to influence versatile fitness, adapt organism to physical load and develop specific...
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