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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Task dependent effects of baroreceptor unloading on motor cortical and corticospinal pathways

Buharin, Vasiliy E. 12 January 2015 (has links)
Corticospinal and intracortical excitability are excitability measures of the central nervous system responsible for motor generation, and are studied for their contribution to fine motor skill execution and learning. Since the need for proper execution of fine motor skills is ever-present and necessary for everyday life, identification of physiological pathways that may disrupt or enhance corticospinal and intracortical excitability is an important research topic. This thesis investigates the effects of baroreceptor unloading on corticospinal and intracortical excitability during various motor tasks. Baroreceptor unloading is a physiological response to common hemodynamic stress (e.g. hypovolemia and orthostasis). The motor tasks investigated are complete muscular relaxation, individual isometric low-force contraction of a muscle, and an isometric co-contraction of a muscle in a joint-stabilizing task. The effects of baroreceptor unloading on corticospinal and intracortical excitability appear to be very task specific. The results are discussed in view of available pharmacological and physiological research, and potential neural pathways for the observed effects are suggested. The overall conclusion is that baroreceptor unloading increases corticospinal excitability and decreases intracortical inhibition in a resting muscle, does not produce any observable effects during individual muscle activity, and decreases corticospinal excitability during joint-stabilizing co-contraction.
12

A Randomized Double Blind Sham-controlled Comparison of Bilateral and Unilateral Repetitive Transcranial Magnetic Stimulation for Treatment-resistant Major Depression

Blumberger, Daniel 04 September 2012 (has links)
Objectives: High frequency left-sided (HFL) and low frequency right-sided (LFR) unilateral repetitive transcranial magnetic stimulation (rTMS) are efficacious in treatment-resistant major depression (TRD). Similar benefit has been suggested for sequential bilateral rTMS (LFR then HFL). Therefore, this study evaluated the efficacy of HFL and sequential bilateral rTMS compared to sham in TRD. Methods: Seventy-four subjects between the ages of 18 and 85 with TRD and a 17-item Hamilton Depression Rating Scale (HDRS) greater than 21 were randomized to receive unilateral, bilateral, or sham rTMS. Remission rates were compared among the three groups. Results: Remission rates differed significantly among the three groups. The remission rate was significantly higher in the bilateral group (34.6%) than the unilateral (4.5%) and sham (5.0%) groups. The remission rate in the unilateral group did not differ from sham group. Conclusion: These findings warrant larger controlled studies that compare the efficacy of sequential bilateral rTMS and HFL rTMS in TRD.
13

A Randomized Double Blind Sham-controlled Comparison of Bilateral and Unilateral Repetitive Transcranial Magnetic Stimulation for Treatment-resistant Major Depression

Blumberger, Daniel 04 September 2012 (has links)
Objectives: High frequency left-sided (HFL) and low frequency right-sided (LFR) unilateral repetitive transcranial magnetic stimulation (rTMS) are efficacious in treatment-resistant major depression (TRD). Similar benefit has been suggested for sequential bilateral rTMS (LFR then HFL). Therefore, this study evaluated the efficacy of HFL and sequential bilateral rTMS compared to sham in TRD. Methods: Seventy-four subjects between the ages of 18 and 85 with TRD and a 17-item Hamilton Depression Rating Scale (HDRS) greater than 21 were randomized to receive unilateral, bilateral, or sham rTMS. Remission rates were compared among the three groups. Results: Remission rates differed significantly among the three groups. The remission rate was significantly higher in the bilateral group (34.6%) than the unilateral (4.5%) and sham (5.0%) groups. The remission rate in the unilateral group did not differ from sham group. Conclusion: These findings warrant larger controlled studies that compare the efficacy of sequential bilateral rTMS and HFL rTMS in TRD.
14

Vliv malé vodní nádrže Strnad na půdní vlhkost na povodí Litovicko-Šáreckého potoka / The impact of small water reservoir on soil moisture in Litovicko-Šárecký brook basin

Kovář, Martin January 2016 (has links)
Currently, when there is a reduction of soil water due to drought, is appropriate measure to start systematic collection of data on soil moisture. In this work the soil moisture content was measured on the Litovicko-Šárecký brook basin near a small water reservoir Strand. The datat were collected by direct method, which mean direct soil sampling and subsequent analysis, and indirect methods concretely gathering data by TMS datalogger. Measured data from direct and indirect methods are essentially agree in this, that small water reservoir Strnad hasnt effect at soil moisture in a distance 200 m. The last part describes the analysis of grain soils using aerometrical methods. The resulting soil types are further used for calibrating the TMS datalogger.
15

The effects of carbonated fluids on the human cortical swallowing motor system

Elshukri, Omsaad January 2013 (has links)
Swallowing is a complex neurophysiological process involving the activation of several components of the central nervous system with bilateral but asymmetric representations of swallowing musculature in the motor cortex. Difficulty in swallowing (dysphagia) in stroke patients has been reported by up to 50% of victims, and can increase morbidity and mortality in this population due to the development of aspiration pneumonia and malnutrition. One of the common factors that predispose patients to dysphagia after a stroke is believed to be the reduced sensory awareness in the oropharyngeal area, which affects the swallowing process. The uses of diet modification to reduce thin liquid aspiration have gained interest but are often unpalatable or have limited success. Carbonated liquid have shown some beneficial effects in swallowing behaviour. However, there is very little evidence to support this intervention. Therefore, the aim of this thesis is to investigate the neurophysiological and behavioural effects of carbonated liquids on swallowing in healthy volunteers.The effects of carbonated solutions on swallowing performance compared to non-carbonated solutions (still water) was investigated in a pilot study and (still water and citric acid) in the main study using reaction time task (chapter 2). Carbonation appears to alter swallowing performance compared to other liquids by improving complex tasks. In addition, beneficial neurophysiological effects of carbonated liquids were evident after 10 minutes of carbonated liquid swallowing compared to still water and citric acid solution in healthy volunteers (chapter 3).In chapter 4, the response of the healthy swallowing motor cortex to carbonated liquids following application of a virtual lesion compared to still water and saliva swallowing, was investigated. Carbonated liquids were able to reverse the inhibitory effect induced by 1 Hz rTMS to the dominant pharyngeal motor representation. Moreover, the beneficial effects of carbonated liquids on swallowing performance, measured with a swallowing reaction times task after application of a virtual lesion was observed in a pilot investigation in healthy volunteers (chapter 5). These data demonstrate that carbonated liquids have beneficial neurophysiological and swallowing performance effects and support notion that the chemical properties of carbonated liquids may provide the required peripheral sensory information that alter the brain swallowing function, which leads to an improvement in the swallowing performance of stroke dysphagic patients. These data lay the foundation for considering the use of carbonation as facilitating stimuli in dysphagic patients.
16

Messung der Aktivität des präfrontalen Cortex mit NIRS vor und nach iTBS-Intervention / Changes in prefrontal cortical activation before and after iTBS - a NIRS study

Schneider, Simone January 2020 (has links) (PDF)
Angsterkrankungen stellen einen großen Anteil an psychischen Erkrankungen dar und gehen zum Teil mit großem Leidensdruck einher. Da die leitliniengerechte Therapie mit hohen Rückfallraten und ca. 25% Nonrespondern einhergeht, stellt sich die Frage nach alternativen Behandlungsmethoden. Transkranielle Magnetstimulation findet als nichtinvasive Behanslungsmethode zunehmend Anwendung bei neurologischen und psychiatrischen Erkrankungen. In der vorliegenden randomisierten, kontrollierten Studie wurde die Wirkung der TMS auf den frontotemporalen (FTC) und dorsolateralen präfrontalen Cortex (dlPFC) untersucht. Dazu wurden 42 gesunde Probanden zwischen 18 und 59 Jahren zur Hälfte TMS-stimuliert, die andere Hälfte wurde scheinstimuliert. Vor und nach Stimulation bzw. Placebostimulation wurde die Aktivität von FTC und dlPFC mit Nah-Infrarotspektroskopie (NIRS) während der Durchführung des Verbal Fluency Tasks (VFT) gemessen. In dieser Studie konnte keine Veränderung der hämodynamischen Gehirnaktivität durch TMS nachgewiesen werden, jedoch äußerten die Probanden der Stimulationsgruppe im Gegensatz zu den Probanden der Placebogruppe, Nebenwirkungen wie Schmerzen oder Muskelzucken verspürt zu haben. Die während des VFT laufende NIRS zeigte eine signifikant höhere Durchblutung und damit Aktivierung des linken FTC im Seitenvergleich und eine signifikant höhere Aktivierung während der semantischen als bei der phonemischen VFT-Bedingung, analog zu früheren, vergleichbaren Untersuchungen. Die Frage, ob sich TMS als mögliche Behandlungsmethode bei Angsterkrankungen eignet, lässt sich anhand der hier vorliegenden Studie nicht abschließend beantworten. / Anxiety disorders constitute a large proportion of mental illnesses and are often accompanied by great strain imposed by suffering. Since guideline-based therapy is characterised by high relapse rates and about 25% of non-responders, the question of alternative treatment methods arises. Transcranial magnetic stimulation as a non-invasive treatment method is being increasingly applied to treat neurological and psychiatric diseases. In the presented randomised, controlled study, the effect of TMS on the frontotemporal (FTC) and dorsolateral prefrontal cortex (dlPFC) was examined. For this purpose, one half of 42 healthy volunteers between 18 and 59 years of age received TMS stimulation while the other half received sham stimulation. Before and after both real and placebo stimulation, the activity of FTC and dlPFC was measured with near-infrared spectroscopy (NIRS) during the execution of Verbal Fluency Tasks (VFT). In this study, no change in hemodynamic brain activity through TMS could be detected. However, contrary to the placebo group volunteers, the stimulation group volunteers reported side effects such as pain or muscle twitching. The NIRS running during VFT showed a significantly increased blood flow and thus an activation of the left FTC in the side comparison, as well as a significantly enhanced activation during the semantic VFT condition in comparison with the phonemic one, analogous to previous comparable examinations. The question of whether TMS presents itself as a potential treatment for anxiety disorders can not be conclusively answered on the basis of the study presented here.
17

Slow Right Prefrontal Transcranial Magnetic Stimulation as a Treatment for Medication-Resistant Depression: A Double-Blind, Placebo-Controlled Study

Kauffmann, Curtis D., Cheema, Muhammad A., Miller, Barney E. 16 March 2004 (has links)
Over the past decade, efforts have been made to assess the positive therapeutic effects of transcranial magnetic stimulation (TMS) by altering the excitability of the brain. We conducted a double-blind, placebo-controlled study to assess the efficacy of right prefrontal slow repetitive TMS in patients with treatment refractory major depression. This pilot study supports the therapeutic potential of rTMS in the low-frequency range of 1 Hz on right prefrontal cortex for the treatment of refractory major depression. Additional studies will be necessary to assess the efficacy of rTMS with different indices (frequency, intensity, and stimulation site) for major depression and other psychiatric diseases.
18

The role of transactive memory in work teams : a review

Gregory, Megan E. 01 January 2009 (has links)
Transactive memory, the transmission and use of knowledge between two or more people, is an important construct to consider when studying work teams. This thesis reviews the literature on transactive memory systems (TMS) in order to summarize what is currently known about TMS and to identify gaps in the literature in need of further investigation. Past TMS research is reviewed according to the operational definitions, antecedents, team processes, outcomes, team performance, and boundary conditions. TMS is most frequently operationalized using Lewis' (2003) TMS scale. Research has focused on three types of antecedents: Communication, Team Characteristics, and Facilitation of TMS. Two common types of team processes found were coordination and team monitoring & backup behavior. Outcomes frequently focused on were team cognition, and team effectiveness. Team performance was ubiquitous in almost all the literature. Boundary conditions, however, varied considerably
19

Conjugate Additions of Carbon Nucleophiles to Cyclopentadienones

Zhang, Ming January 2007 (has links)
No description available.
20

the Effects of Cryotherapy on Quadriceps Corticomotor Excitability in Patients with Anterior Knee Pain

Kunisch, Robert W. January 2015 (has links)
No description available.

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