Chicken embryos were chronically exposed to the ?1- blocker atenolol during one of three stages: mesonephros (E7-E9), mesonephros-metanephros (E11-E13), or metanephros (E15-E17). Mesonephros group hearts were larger than all other groups (P < 0.01). Mesonephros and metanephros group kidneys were larger than all remaining groups (P < 0.0001). The mesonephros group nephron number was ~40% lower than control values (P = 0.002). Glomerular areas were 26% and 18% larger than the control group in the mesonephros and metanephros groups, respectively (P < 0.001). These data suggest an E7-E9 critical window of cardiovascular and renal development for atenolol. Acute atenolol exposure in E15 embryos showed an increase in mean arterial pressure with all but the highest dose. All doses significantly decreased heart rate.

A low cost Heart Beat Monitoring device (HBMD) for detecting heart beat in beats per minute is presented in this thesis. An optical technique called “Photoplethysmography” is utilized by attaching to the base of the finger for monitoring beat to beat pulsation. Two major design issues addressed in this research is to achieve a strong and accurate PPG signal and simultaneously minimizing physiological artefacts and interference. In order to achieve the aim and objectives of the research, this thesis thoroughly explores two new signal conditioning hardware designs. Firstly is the design and fabrication of a low cost reflectance mode PPG heart monitor using parallel port interfacing and secondly are the design and development of a portable transmission mode PPG heart monitor using microcontroller PIC16F84A and PIC16F87. Both PPG heart monitor design is divided into three phases. First is the detection of weak pulses through the fingertip. The PPG signal is then amplified, filtered and digitized by the signal processing unit. Finally the heart rate is calculated, analyzed and displayed on the computer using parallel port interface and on the liquid crystal display using microcontroller PIC16F87. A comprehensive circuit design and analysis work was implemented verified by Proteus VSM circuit simulations and laboratory experiments. Data is presented from the method comparison study in which heart rates measured with the reflectance mode PPG and portable transmission mode PPG heart monitor were compared with those measured with standard techniques on 13 human subjects. Benchmarking tests with approved pulse oximeter and blood pressure monitor Omron M6 reveals that the PPG heart monitor is comparable to those devices in displaying the heart rate. It is also verified through experiments that both PPG heart monitor design fulfill the objectives, including achieving strong and accurate PPG signal, reduction in physiological artefacts and interference and financially low in cost. As the conclusion, the current version of the reflectance mode PPG and portable transmission mode PPG heart monitor successfully measure heart rates fast and reliably in most subjects in different body position. The PPG heart monitor proposed avoid the need to apply electrodes or other sensors in the correct position which directly minimizes the preparation time drastically. This makes the PPG heart monitor more attractive for heart monitoring purpose and its advantage should be explored further.

Research on the various subtypes of aggression has documented differences in the experience of anger and the expression of angry aggression. Mixed proactive and reactive aggressive individuals exhibit reactive aggression but, unlike reactive aggressive individuals, fail to exhibit angry expressions or physiological arousal. Similar to the proactive group, individuals with psychopathic traits have been found to exhibit emotional underreactivity, and physiological underarousal, while still exhibiting reactive aggression. The present study examined 85 boys (ages 13 to 18) from a detention center. Three groups of aggressive boys were identified via cluster analysis based on the self-report of types of aggressive behavior: a primarily reactive aggressive group (n=29), a mixed reactive and proactive group (n=16), and a low aggressive group (n=40). The three groups were compared on aggressive responding (during a computerized provocation task with low and high provocation trials), on callous and unemotional traits (CU) and on psychophysiological indices of emotional reactivity. All aggressive groups showed greater aggressive responding to high provocation than to low provocation. The mixed aggressive group showed high aggressive responding across all provocation levels, including the no provocation condition, while the reactive aggressive group only showed high levels similar to the mixed aggressive group during low provocation. Unexpectedly, the reactive and mixed aggressive groups reported higher levels of CU traits than the other group. Although the groups did not differ on psychophysiological activity/reactivity, higher levels of CU traits were related to lower skin conductance responses to provocation. Thus, the contribution of high and low CU traits in the three groups to psychophysiological activity/reactivity was examined. Interestingly, the low and mixed aggressive groups who were high on CU traits had lower sympathetic arousal (indexed by skin conductance) and lower sympathetic reactivity to provocation. Thus, the mixed aggressive group showed a general disconnect between their angry aggression (on the provocation task) and their sympathetic reactivity to provocation. However, this was true only if they also showed high rates of CU traits. These results suggest that interventions targeted toward individuals who exhibit particular subtypes of aggression may be more beneficial if the presence of CU traits is also considered.

We attempted to identify the psychobiological mechanisms that mediate the process by which the sensation seeking trait culminates in behavior. We used the Sensation Seeking Scales to assess the SS trait in individuals who expressed a desire to skydive. We obtained measures of autonomic (heart rate) and endocrine (salivary cortisol) activity before, during and after skydiving. To distinguish the contribution of novelty, we compared novices (N=29) to experienced jumpers (N=15). All jumpers exhibited HPA-axis activation; novices exhibited a prolonged response and more extreme peak in cortisol compared to experienced jumpers, suggesting that novelty contributes to an intense pattern of stress responding. Both groups displayed increases in heart rate; there were no significant differences between the groups, indicating that repeated exposure to the stressor did not habituate this system. We provided evidence that the stress response systems instantiate novelty and risk to motivate and reward behavioral expressions of the SS trait.

Through a series of original research articles, this thesis explores the characteristics of autonomic cardiac regulation and respiratory function during sleep in association with depression and antidepressant medication use and validates a novel diagnostic biomarker of depression. Cardiorespiratory dysfunction during sleep may contribute to the increased risk of developing cardiovascular disease amongst individuals with depression. Sleep represents a unique physiological state shielded from many external confounding factors and may be a more relevant window to observe the effects of depression on cardiorespiratory function. In a first study, we found that depression was associated with abnormal autonomic modulation of cardiac activity during sleep. Specifically, depression was associated with reduced heart rate variability compared to healthy controls, and this difference was most prominent during sleep as compared to wake, which may indicate impairments in the parasympathetic modulation of the cardiac sinoatrial node. Secondly, we validated a machine-learning algorithm that uses patterns of heart rate during sleep to identify depression. This algorithm was found to have 79.9% classification accuracy, based on the differences in autonomic modulation associated with distinct mental states. The algorithm was highly generalizable across different depression subgroups and thus may be useful as an adjunct diagnostic tool. Finally, we found that the use of antidepressants, particularly serotonergic agents, was associated with worse sleep-related respiratory disturbances compared to non-medicated individuals with depression and those using non-serotonergic antidepressants. We proposed that depression-related alterations in serotonin receptor expression and binding may shape the response of the respiratory system to the use of serotonergic agents. Considering the high comorbidity between depression and sleep-related breathing disturbances and their impact on cardiovascular health, this has great clinical implications for the management of depression. Taken together, these results show that depression is associated with several sleep-related abnormalities in terms of cardiorespiratory function, which may represent a valid biomarker of depression.

Cervical vagal nerve stimulation (VNS) has been studied in the context of several conditions including epilepsy and depression. However, its effects on glucose metabolism, and its potentially beneficial effects in type II diabetes, have not yet been evaluated in humans. Efferent parasympathetic activation reduces hepatic glucose release and increases pancreatic insulin secretion, while afferent parasympathetic activation may increase hepatic glucose release and inhibit insulin secretion potentially through sympathetic activation. Thus, the effect of combined afferent and efferent cervical VNS is difficult to predict. We hypothesized that selective efferent VNS would decrease blood glucose concentration [Glu] and that selective afferent VNS would increase [Glu]. To investigate these potentially contrasting effects of efferent vs. afferent parasympathetic signaling, we recorded [Glu] and serum insulin and glucagon levels before and during 120 min of VNS in anesthetized rats. The nerve was left intact for combined afferent and efferent VNS (n=9) or sectioned proximal or distal from the stimulation electrode for selective efferent (n=8) of afferent (n=7) VNS, respectively. We found that afferent VNS caused a strong and sustained increase in [Glu] (+108.9±20.9% or +77.6±15.4% after 120 min of combined afferent and efferent VNS or selective afferent VNS) that was not accompanied by an increase in serum insulin concentration. Combined afferent and efferent VNS significantly increased serum glucagon concentration (57.6±23.4% at 120 min of VNS), while selective afferent VNS did not increase glucagon levels. Conversely, selective efferent VNS increased [Glu] only temporarily (+28.8±11.7% at 30 min of VNS). This response coincided with a transient increase in serum glucagon concentration at 30 min of VNS (31.6±8.3%) and a strong and sustained increase in serum insulin concentration (+71.2±27.0% after 120 min of VNS). These findings demonstrate that afferent VNS may increase [Glu] by suppressing pancreatic insulin release, while efferent VNS transiently increases [Glu] by stimulating glucagon secretion before reducing levels to or below baseline values by stimulating the release of insulin. Thus, selective efferent VNS may be potentially effective in the treatment of type II diabetes.

The bond between pet and owner has been shown to decrease stress-related physical, mental, and emotional disorders by lowering blood pressure and heart rate. The purpose of this study was to examine whether a nonpet canine would have the same effect in reducing physical symptoms of stress as a known dog. Human-animal bond theory, Human pressor test. Data were analyzed using repeated measures, analyses of variance, and t tests. Results indicated that interaction with a strange dog lowered heart rate and blood pressure significantly faster in the experimental group than in the control group. The positive social change implications of this research include policy and procedural accommodations for the use of canines as comfort animals for individuals in stressful conditions.

Today many strategies of monitoring health status and well-being are done through measurementmethods that are connected to the body, e.g. sensors or electrodes. These are often complicatedand requires personal assistance in order to use, because of advanced hardware and attachmentissues. This paper proposes a new method of making it possible for a user to self-monitoring theirwell-being and health status over time by using a non-contact camera system. The camera systemextracts physiological parameters (e.g. Heart Rate (HR), Respiration Rate (RR), Inter-bit-Interval(IBI)) based on facial color variations, due to blood circulation in facial skin. By examining anindividual’s physiological parameters, one can extract measurements that can be used in order tomonitor their well-being. The measurements used in this paper is features of heart rate variability(HRV) that are calculated from the physiological parameter IBI. The HRV features included andtested in this paper is SDNN, RMSSD, NN50 and pNN50 from Time Domain and VLF, LF andLF/HF from Frequency Domain. Machine Learning classification is done in order to classifyan individual’s sleepiness from the given features. The Machine Learning classification modelwhich gave the best results, in forms of accuracy, were Support Vector Machines (SVM). The bestmean accuracy achieved was 84,16% for the training set and 81,67% for the test set for sleepinessdetection with SVM. This paper has great potential for personal health care monitoring and can befurther extended to detect other factors that could help a user to monitor their well-being, such asmeasuring stress level

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Research has shown that psychotherapy patients experience increased physiological responsivity to stress which might negatively impact their experience in psychotherapy and their overall progress and outcome. The purpose of the present study was to investigate the effect of a heart rate variability biofeedback intervention on the physiological stress responsiveness and the psychotherapy outcomes of participants in psychotherapy. Forty college students attending psychotherapy at their university counseling center were divided into an experimental group and a control group. The experimental group participated in a 6-week biofeedback intervention and we assessed their physiological stress reactivity before and after implementation of the intervention, compared to a matched control group. The Trier Social Stress Test (TSST) was administered pre- and post-intervention to induce a stress reaction. It was hypothesized that psychotherapy patients involved in the biofeedback intervention would show decreased physiological stress reactivity to and faster physiological recovery from a laboratory induced stressor post-intervention compared to psychotherapy patients in the matched control group. It was also hypothesized that these participants would demonstrate larger distress reduction after implementation of the intervention. Results of the study found no significant main effect of the TSST on systolic blood pressure, heart rate, and HRV. There however was a main effect on diastolic blood pressure. The only variable that significantly differed between groups was the LF/HF ration. The results also revealed no significant change from pre-intervention baseline to post-intervention heart rate, blood pressure, and HRV, suggesting that the HRV biofeedback intervention was not effective in changing the stress response over time. Regarding levels of distress, results also revealed no statistical between group differences post-intervention, although the biofeedback group appeared to report significantly lower levels of distress post-intervention.