Tesi sul tema "Brain"
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Wolburg, Martin. "On brain drain, brain gain, and brain exchange within Europe /". Baden-Baden : Nomos Verlagsgesellschaft, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015306300&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Testo completo
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Sebastián, Romagosa Marc. "Brain computer interfaces for brain acquired damage". Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670835.
Testo completoAbstract (sommario):
El terme Interfície Cervell-Ordinador (ICC), va sorgir als anys 70 pel Dr. Jacques J. Vidal, que mitjançant l’ús de l’electroencefalografia (EEG) fou el primer a intentar proporcionar una sortida alternativa als senyals cerebrals per controlar un dispositiu extern. L’objectiu principal d’aquesta fita era ajudar als pacients amb problemes de moviment i comunicació a relacionar-se amb el seu entorn.
Des de llavors, molts neurocientífics han emprat aquesta idea i han intentat posar-la en pràctica utilitzant diferents mètodes d’adquisició i processament del senyal, nous dispositius d’interacció, noves metes i objectius. Tot això ha facilitat l’aplicació d’aquesta tecnologia en moltes àrees, i actualment les ICC s’utilitzen per jugar a videojocs, moure cadires de rodes, facilitar l’escriptura en persones sense mobilitat, definir criteris i preferències en el món del comerç i el consum, o inclús poden servir com a detector de mentides.
Tot i així, el sector que presenta un major avenç en el desenvolupament de les ICC, és el sector biomèdic. A grans trets, podem utilitzar les ICC amb dues finalitats diferents dins de la neurorehabilitació; substituint una funció perduda o induint canvis en la plasticitat neuronal amb l’objectiu de restaurar o compensar la funció perduda.
Existeixen diferents principis per al registre dels senyals del cervell; de manera invasiva, col·locant els elèctrodes de registre dintre de la cavitat cranial, o de manera no invasiva, col·locant els elèctrodes de registre fora de la cavitat cranial. El mètode més conegut i difós és l’EEG. El seu ús és molt adequat en entorns clínics, té una resolució temporal molt precisa i és possible obtenir una retroalimentació en temps real que pot induir la plasticitat cortical i el restabliment de la funció motora normal.
En aquesta tesi presentem tres objectius diferents: (1) avaluar els afectes clínics de la rehabilitació mitjançant les ICC en pacients amb ictus, ja sigui realitzant un meta-anàlisi dels estudis publicats o avaluant els canvis funcionals dels pacients amb ictus després de la teràpia d’ICC; (2) explorar paràmetres alternatius per quantificar els efectes de les ICC en pacients amb ictus, avaluant diferents biomarcadors de l’EEG en pacients amb aquesta patologia i correlacionant aquests marcadors amb els resultats de les escales funcionals; (3) optimitzar el sistema ICC mitjançant la gamificació d’un avatar.El término Interfaz Cerebro-Computadora (ICC) surgió en los años 70 por el Dr. Jacques J. Vidal, que mediante el uso de la electroencefalografía (EEG) trató de dar una salida alternativa a las señales del cerebro para controlar un dispositivo externo. El objetivo principal de esta hazaña era ayudar a los pacientes con problemas de movimiento o comunicación a relacionarse con el entorno. Desde entonces, muchos neurocientíficos han utilizado esta idea y han tratado de ponerla en práctica utilizando diferentes métodos de adquisición y procesamiento de señales, nuevos dispositivos de interacción y nuevas metas y objetivos. Todo ello ha facilitado la aplicación de esta tecnología en muchas áreas y actualmente las ICC se utilizan para jugar a videojuegos, mover sillas de ruedas, facilitar la escritura en personas sin movilidad, establecer criterios y preferencias de compra en el mundo del comercio y el consumo, o incluso pueden servir como detector de mentiras. Sin embargo, el sector que presenta un mayor avance y desarrollo de las ICC es el sector biomédico. A grandes rasgos podemos utilizar las ICC con dos finalidades distintas dentro de la neurorehabilitación; sustituir una función perdida o inducir cambios en la plasticidad neuronal con el objetivo de restaurar o compensar dicha función perdida. Hay diferentes principios para el registro de las señales del cerebro; de forma invasiva, colocando los electrodos de registro dentro de la cavidad craneal, o no invasiva, colocando los electrodos de registro fuera de la cavidad craneal. El método más conocido y difundido es la EEG. Su uso es adecuado para entornos clínicos, tiene una resolución temporal muy precisa y su retroalimentación en tiempo real puede inducir la plasticidad cortical y el restablecimiento de la función motora normal. En esta tesis presentamos tres objetivos diferentes: (1) evaluar los efectos clínicos de la rehabilitación mediante las ICC en pacientes con ictus, ya sea realizando un meta-análisis de los estudios publicados o evaluando los cambios funcionales en los pacientes con ictus después de la terapia de ICC; (2) explorar parámetros alternativos para cuantificar los efectos de las ICC en pacientes con ictus, evaluando diferentes biomarcadores de electroencefalografía en pacientes con esta patología y correlacionando los posibles cambios en estos parámetros con los resultados en las escalas funcionales; (3) optimizar el sistema ICC utilizando mediante la gamificación de un avatar.
The term Brain Computer Interface (BCI) emerged in the 70's by Dr. Jacques J Vidal, who by using electroencephalography (EEG) tried to give an alternative output to the brain signals in order to control an external device. The main objective of this feat was to help patients with impaired movement or communication to relate themselves to the environment. Since then many neuroscientists have used this idea and have tried to implement it using different methods of signal acquisition and processing, new interaction devices, new goals and objectives. All this has facilitated the implementation of this technology in many areas and currently BCI is used to play video games, move wheelchairs, facilitate writing in people without mobility, establish criteria and purchase preferences in the world of marketing and consumption, or even serve as a lie detector. However, the sector that presents the most marked progress and development of BCI is the biomedical sector. In rough outlines we can use BCI with two different purposes within the neurorehabilitation; to substitute a lost function or to induce neural plasticity changes with the aim to restore or compensate the lost function. To restore a lost function by inducing neuroplastic changes in the brain is undoubtedly a challenging strategy but a feasible goal through BCI technology. This type of intervention requires that the patient invests time and effort in a therapy based on the practice of motor image and feedback mechanisms in real time. There are different principles to record the brain signals; invasively, placing the recording electrodes inside the cranial cavity, or non-invasive, placing the recording electrodes outside of the cranial cavity. The best known and most widespread one is EEG, since they are suitable for clinical environments, have a highly accurate temporal resolution and their real-time feedback can induce cortical plasticity and the restoration of normal motor function. On this thesis we present three different objectives: (1) to evaluate the clinical effects of rehabilitation based on BCI system in stroke patients, either by performing a meta-analysis of published studies or by evaluating functional changes in stroke patients after BCI training; (2) to explore alternative parameters to quantify effects of BCI in stroke patients, by evaluating different electroencephalography biomarkers in stroke patients and correlating potential changes in these parameters with functional scales; (3) to optimize the BCI system by using a new gamified avatar.
3
Liu, Mianxin. "The brain at criticality : variability of brain spontaneous activity and relevance to brain functions". HKBU Institutional Repository, 2020. https://repository.hkbu.edu.hk/etd_oa/809.
Testo completoAbstract (sommario):
The brain activities are characterized by spontaneous and persistent irregular fluctuations in space and time. Criticality theory from statistical physics has been proposed as a principle to explain the variability in normal brain spontaneous activity and has suggested the functional benefits of variability, such as maximized dynamic range of response to stimuli and information capacity. In parallel, the brains show variability in other aspects, such as the structural heterogeneity across brain regions, the intra-individual variability across experimental trials, and the behavior difference across groups and individuals. The associations between the variability of spontaneous activities and these different types of structural, intra and inter-individual variabilities remain elusive. My doctoral study thus aimed to bridge the brain variability and the above-mentioned variations based on criticality theory and analysis of empirical data. As a preparatory analysis, we first collected evidence to prove criticality in human functional magnetic resonance imaging (fMRI) data. The advanced statistical criteria were used to exclude potential artefacts that can induce power-law scaling without the mechanism of criticality. In the first part of the study, we addressed methodological issue and tested whether several measures of either spatial or temporal complexity due to experimental limitations could be reliable proxy of spatiotemporal variability (related to criticality) in vivo. The high spatiotemporal resolutions of whole-cortex optical voltage imaging in mice brain during the waking up from anesthesia enabled simultaneous investigation of functional connectivity (FC), Multi-Scale Entropy (MSE, measure of temporal variability), Regional Entropy (RE, quantity of spatiotemporal variability) and the interdependency among them under different brain states. The results suggested that MSE and FC could be effective measures to capture spatiotemporal variability under limitation of imaging modalities applicable to human subjects. This study also lays methodological basis for the third study in this thesis. In the second study, we explored the interaction between spontaneous activity and evoked activity from mice brain imaging under whisker stimulus. The whisker stimulus will first evoke the local activation in sensory cortex and then trigger whole-cortex activity with variable patterns in different experimental trials. This trial-to-trial variability in the cortical evoked component was then attributed to the changes of ongoing activity state at stimulus onset. The study links ongoing activity variability and evoked activity variability, which further consolidates the association between ongoing activity and brain functions. In the third study, we measured the signal variability of the whole brain from resting state fMRI, and developed the multivariate pattern of cortical entropy, called entropy profile, as reliable and interpretable biomarker of individual difference in cognitive ability. We showed that the whole cortical entropy profile from resting- state fMRI is a robust personalized measure. We tested the predictive power for general and specific cognitive abilities based on cortical entropy profiles with out- of-sample prediction. Furthermore, we revealed the anatomical features underlying cross-region and cross-individual variations in cortical entropy profiles. This study provides new potential biomarker based on brain spontaneous variability which could benefit the applications in psychology and psychiatry studies. The whole study laid a foundation for brain criticality-/variability-based studies and applications and broadened our understanding of the associations between neural structures, functional dynamics and cognitive ability
4
Dave, Nimita D. "Brain/Brain Tumor Pharmacokinetics and Pharmacodynamics of Letrozole". University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1368013158.
Testo completo
5
Woody, Christine Buchanan. "Right-brain/left-brain communication in the church". Theological Research Exchange Network (TREN), 2007. http://www.tren.com/search.cfm?p064-0137.
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Álvarez, Fernández Jorge Luis, Segura Claudia Alejandra Muñoz, Apolaya Juan José Polack e Bautista Karina Rodríguez. "Brain Freeze". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2018. http://hdl.handle.net/10757/625355.
Testo completoAbstract (sommario):
El presente trabajo de investigación tiene como principal propósito el desarrollar un modelo de negocio innovador, a partir de la creación de un helado, hecho a base de Polifenol, el cual posee como valor agregado el no derretirse con facilidad. “Brain Freeze” conforma una propuesta innovadora para el mercado de los helados en la actualidad, debido a su principal ventaja competitiva y comparativa frente a la competencia existente en el mercado.
Asimismo, a partir del presente documento escrito, se desarrollan todos los principales aspectos para la correcta y eficiente realización del presente proyecto y su pronta ejecución en Lima Metropolitana; así como también todos los detalles financieros requeridos para su evaluación y pronta inversión en el modelo de negocio.
Con la finalidad de poder establecer una planificación que permita estimaciones de mercado reales, la presente investigación tomó en cuenta la información respectiva y actualizada del segmento de mercado al cual se espera atender. El concepto de “Brain Freeze” propone el desarrollo de cinco módulos de ventas en cinco de los principales centros comerciales, con la finalidad de poder abarcar a la mayor afluencia de clientes, los cuales recurren a los principales centros comerciales de Lima Metropolitana y convertirse así en una marca Top of Mind, dentro de un plazo de cinco años desde su lanzamiento.The main purpose of this paper is to develop an innovative business model, based on the creation of an ice cream made from Polyphenol, which has the added value of not melting easily. "Brain Freeze" forms an innovative proposal for the ice cream market at present, due to its main competitive and comparative advantage over the existing competition in the market. Likewise, from this written document, all the main aspects are developed for the correct and efficient realization of this project and its prompt execution in Metropolitan Lima; as well as all the financial details required for its evaluation and prompt investment in the business model. With the purpose of being able to establish a planning that allows real market estimations, the present investigation took into account the respective and updated information of the market segment to which it is expected to attend. The concept of "Brain Freeze" proposes the development of five sales modules in five of the main shopping centers, in order to cover the largest number of customers, who turn to the main shopping centers in Metropolitan Lima and thus become in a Top of Mind brand, within five years of its launch.
Trabajo de investigación
7
Подолкова, Світлана Віталіївна, Светлана Витальевна Подолкова, Svitlana Vitaliivna Podolkova e I. Strizhakov. "Human brain". Thesis, Вид-во СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/22106.
Testo completo
8
Sylenko, E. V. "Brain-computer". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45871.
Testo completoAbstract (sommario):
The development of different variants of the interface ―brain-computer‖ (BCI) in recent years ceased to be an experimental direction and finds its practical application. What were the expectations like, what works now and what to expect from this technology in the future?
9
Watson, Charles. "Brain mapping". Thesis, The University of Sydney, 2011. https://hdl.handle.net/2123/28840.
Testo completoAbstract (sommario):
These publications are a summary of work I have completed in brain mapping over many years. The work includes one book (The Rat Brain in Stereotaxic Coordinates, 6th compact edition), ten articles on hindbrain and spinal cord anatomy published in peer reviewed journals between 1975 to 2011, and five published chapters on spinal cord anatomy, including two spinal cord atlases.
Over my career I have published 15 books on the anatomy of the brain and spinal cord of experimental animals. I am first author or equal co-author of ten of these books. The most successful of these books, "The Rat Brain in Stereotaxic Coordinates" (Paxinos and Watson, l 982, 1986, 1996, 1998, 2005, 2007), has earned over 50,000 citations since it was first published in 1982. The second edition alone is ranked 32 in the Thomson ISI 50 most cited publications of all time, having been cited 17,093 times up to January 2006. Dr George Paxinos and l are equal
contributors to this work; the order of authors was decided on alphabetical precedence.
10
Babalola, Karolyn Olatubosun. "Brain-computer interfaces for inducing brain plasticity and motor learning: implications for brain-injury rehabilitation". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41164.
Testo completoAbstract (sommario):
The goal of this investigation was to explore the efficacy of implementing a rehabilitation robot controlled by a noninvasive brain-computer interface (BCI) to influence brain plasticity and facilitate motor learning. The motivation of this project stemmed from the need to address the population of stroke survivors who have few or no options for therapy.
A stroke occurs every 40 seconds in the United States and it is the leading cause of long-term disability [1-3]. In a country where the elderly population is growing at an astounding rate, one in six persons above the age of 55 is at risk of having a stroke. Internationally, the rates of strokes and stroke-induced disabilities are comparable to those of the United States [1, 4-6]. Approximately half of all stroke survivors suffer from immediate unilateral paralysis or weakness, 30-60% of which never regain function [1, 6-9]. Many individuals who survive stroke will be forced to seek institutional care or long-term assistance.
Clinicians have typically implemented stroke rehabilitative treatment using active training techniques such as constraint induced movement therapy (CIMT) and robotic therapy [10-12]. Such techniques restore motor activity by forcing the movement of weakened limbs. That active engagement of the weakened limb movement stimulates neural pathways and activates the motor cortex, thus inducing brain plasticity and motor learning. Several studies have demonstrated that active training does in fact have an effect on the way the brain restores itself and leads to faster rehabilitation [10, 13-15]. In addition, studies involving mental practice, another form of rehabilitation, have shown that mental imagery directly stimulates the brain, but is not effective unless implemented as a supplemental to active training [16, 17]. Only stroke survivors retaining residual motor ability are able to undergo active rehabilitative training; the current selection of therapies has overlooked the significant population of stroke survivors suffering from severe control loss or complete paralysis [6, 10].
A BCI is a system or device that detects minute changes in brain signals to facilitate communication or control. In this investigation, the BCI was implemented through an electroencephalograph (EEG) device. EEG devices detect electrical brain signals transmitted through the scalp that corresponded with imagined motor activity. Within the BCI, a linear transformation algorithm converted EEG spectral features into control commands for an upper-limb rehabilitative robot, thus implementing a closed-looped feedback-control training system. The concept of the BCI-robot system implemented in this investigation may provide an alternative to current therapies by demonstrating the results of bypassing motor activity using brain signals to facilitate robotic therapy.
In this study, 24 able-bodied volunteers were divided into two study groups; one group trained to use sensorimotor rhythms (SMRs) (produced by imagining motor activity) to control the movement of a robot and the other group performed the 'guided-imagery' task of watching the robot move without control. This investigation looked for contrasts between the two groups that showed that the training involved with controlling the BCI-robot system had an effect on brain plasticity and motor learning.
To analyze brain plasticity and motor learning, EEG data corresponding to imagined arm movement and motor learning were acquired before, during, and after training. Features extracted from the EEG data consisted of frequencies in the 5-35Hz range, which produced amplitude fluctuations that were measurably significant during reaching. Motor learning data consisted of arm displacement measures (error) produced during an motor adaptation task performed daily by all subjects.
The results of the brain plasticity analysis showed persistent reductions in beta activity for subjects in the BCI group. The analysis also showed that subjects in the Non-BCI group had significant reductions in mu activity; however, these results were likely due to the fact that different EEG caps were used in each stage of the study. These results were promising but require further investigation.
The motor learning data showed that the BCI group out-performed non-BCI group in all measures of motor learning. These findings were significant because this was the first time a BCI had been applied to a motor learning protocol and the findings suggested that BCI had an influence on the speed at which subjects adapted to a motor learning task. Additional findings suggested that BCI subjects who were in the 40 and over age group had greater decreases in error after the learning phase of motor assessment. These finding suggests that BCI could have positive long term effects on individuals who are more likely to suffer from a stroke and possibly could be beneficial for chronic stroke patients.
In addition to exploring the effects of BCI training on brain plasticity and motor learning this investigation sought to detect whether the EEG features produced during guided-imagery could differentiate between reaching direction. While the analysis presented in this project produced classification accuracies no greater than ~77%, it formed the basis of future studies that would incorporate different pattern recognition techniques.
The results of this study show the potential for developing new rehabilitation therapies and motor learning protocols that incorporate BCI.
11
Horemuz, Michal. "Morphable Brain Model for Monitoring Disease Related Brain Changes". Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-164967.
Testo completoAbstract (sommario):
Alzheimer's Disease is a devastating neurodegenerative disease that costs billions of dollars each year worldwide. Early diagnosis of the disease can greatly improve patients well-being. There are computer-aided methods that can detect the disease using high quality brain scans. However, these kinds of scans are very rare in the clinic so the methods are not applicable. This paper explores methods for detecting Alzheimer's Disease based on deformation fields of brain scans. This has the advantage of being robust to intensity error, and thus applicable on lower quality scans. The methods were tested using low quality MRI scans, with a slice thickness of 5.5mm. Using a morphable model, which captures the general shape of a brain, the result of classifying diseased and healthy brains had 94/97/92 accuracy/sensitivity/specificity, which is comparable to other methods which use high quality images. This result suggests it may be possible to use methods based on deformation fields in research using clinical data, and possibly for clinical use as well.Alzheimers sjukdom är en förödande neurodegenerativ sjukdom som kostar hela världen miljarder dollar årligen. Tidig diagnos av sjukdomen kan forbattra patienternas välbennande. Det finns datorstödda metoder som kan upptäcka sjukdomen med hjälp av högkvalitativa hjärnskanningar. Dessa typer av skanningar är mycket sällsynta i den kliniska vardagen och därfor ar de metoderna inte tillämpliga for kliniskt bruk. Denna rapport utforskar metoder for att upptäcka Alzheimers sjukdom baserade på deformationsfält av hjärnskanningar. Detta har fördelen att vara robust för intensitetfel och därmed tillämpligt på hjarnskanningar av lägre kvalitet. Metoderna testades med lågkvalitet MRI hjarnskanningar med en skivtjocklek pa 5,5 mm. Tillämpning av en "morphable" modell, som fångar den generella hjärnformen, gav 94/97/92 noggrannhet/känslighet/specificitet för klassifikation av sjuka och friska hjärnor. Detta ar jämförbart med andra metoder som använder högkvalitativa bilder. Detta resultat antyder att det kan vara möjligt att använda metoder baserade pa deformationsfält i forskning med kliniska data, och ger även möjligheten for klinisk användning.
12
Wu, Dali. "Probing and modulating brain circuits by deep brain stimulation". Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:54c6d5f7-e847-4db6-9d19-0c2b9c1f55b4.
Testo completoAbstract (sommario):
Backgrounds. The periaqueductal grey(PAG) plays an important role in the descending pain modulation systems, which has been known to inhibit incoming nociceptive signals at the level of the spinal dorsal horn. But pain mechanism involves the brain and the spinal cord to maintain homeostasis, so theoretically pain modulation mechanism should involve both direction: ascending and descending pathways to the brain and spinal cord dorsal horn. However, literature addressing this question is limited. The sensory thalamus is the most important brain area receiving sensory signals. Moreover, with the fact that evidence indicates the PAG and the thalamus have functional connections, therefore we wanted to test if there is a functional connection between the PAG and the sensory thalamus related to pain modulation. Aims. To investigate the functional connectivity between the periaqueductal grey and the sensory nuclei of the thalamus in pain modulation Methods. Three experiments have been conducted. The first experiment is to investigate the effect of PAG DBS on the sensory thalamus, and vice versa, in chronic neuropathic pain patients. The second experiment is to estimate the change of spectral coherence between the sensory thalamus and the PAG during various pain states, when chronic neuropathic pain patients were being peripheral stimulated by ice to evoke pain. The third experiment is to test whether the functional connectivity between the two areas would be affected by general anaesthetics propofol. Results. PAG DBS inhibited the sensory thalamus with decreasing thalamic delta, theta, alpha and beta power, and sensory thalamus DBS excited the PAG with increasing PAG delta and theta power. The PAG and the sensory thalamus interact reciprocally at short latency, which may be related to pain modulation. The sensory thalamus and the periaqueductal grey also have high gamma coherence which would be inhibited by pain. This high-gamma coherence was increased during propofol induction period which is compatible with the hypothesis that propofol induces loss of consciousness via its GABAergic activity. Conclusions. This thesis suggests that the sensory thalamus and the periaqueductal grey have a reciprocal connection. Functionally this connectivity might be related to pain modulation. Also this functional connectivity might represent the fact that the transmission and processing of pain signals is always monitored and modified by central pain modulation systems so that organisms can respond properly to the incoming signals.
13
Lalani, Sanam Jivani. "Effects of Traumatic Brain Injury on Pediatric Brain Volume". BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6924.
Testo completoAbstract (sommario):
This study investigated the effects of lesion presence within larger brain networks (e.g., default mode network (DMN), salience network (SN), and mentalizing network (MN)) in the chronic phase of a pediatric traumatic brain injury (TBI) and the effect on social function. We compared children with a TBI to children with an orthopedic injury (OI) with three different aims. The first aim was to determine whether network volume differed by group (e.g., TBI vs. OI). Second, investigate if lesion presence in a sub component region of the network resulted in total network volume loss for that network. Finally, learn whether network volume would predict outcome on the Behavior Assessment System for Children, Second Edition (BASC-2). Approximately 184 participants (65% male; 70% Caucasian) between the ages of 6-17 years completed testing and a structural MRI scan in the chronic stage (at least one-year post-injury) of the injury. Injury severity included complicated mild, moderate, and severe TBI. Radiological findings were analyzed using recommendations from the Common Data Elements' core (presence or absence of a lesion) and supplementary (lesion type and location) recommendations. Volumetrics for all participants were obtained with FreeSurfer to quantify total network volumes for the DMN, SN, and MN. The parent of each participant completed a behavioral measure for externalizing and internalizing behaviors. Three sets of statistical analyses were completed, including multivariate analysis of covariance, analysis of covariance, and multiple regression, for each of the three aims of the study, respectively. There were significant differences in total DMN volume between the two groups and participants with lesions solely in the MN had lower total MN volume. Moreover, lower total MN volume was associated with worse functioning on measures of externalizing and internalizing behaviors. The larger implications, including developmental and social implications, of these findings are discussed.
14
Nguyen, Chi Hong. "To stay or to return? : brain drain or brain gain? /". [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18731.pdf.
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Kalantari, Saeed. "Characterizing magnetization exchange in healthy human brain and bovine brain". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44475.
Testo completoAbstract (sommario):
Multi component T₂ relaxation imaging is an established MRI technique for measuring myelin water (MW, water molecules trapped between myelin sheath bilayers). Myelin water fraction (MWF, the fraction of central nervous system water with a short T₂) has been quantitatively correlated to histological staining for myelin in central nervous system tissue and hence is considered an in vivo measure of myelin content. Various studies have reported on the measurement of MWF with a diverse range of neurological diseases such as Multiple Sclerosis (MS), Schizophrenia, epilepsy, and Phenylketonuria (PKU).
Although T₂ relaxation is the main probe for measuring MWF, understanding longitudinal relaxation, T1, is essential in a number ways such as the following:
1) Estimation of the corrections for myelin water fraction that need to be taken into account due to water exchange processes in white matter in vivo is highly dependent on T₁ relaxation. 2) Investigating the effect of T1-weighting in MWF measurements at short TR. This is especially important due to recent breakthroughs in developing rapid 3-D whole brain approaches to MWF measurements that are pushing towards shorter and shorter TR times in order to make this technique a valuable clinical imaging tool.
First, in vivo MRI data from multi-component T₂ relaxation from 57 healthy subjects collected at 3.0 T was analyzed to estimate the corrections which have to be taken into account due to magnetization exchange in white matter. These results showed that these MWF corrections were less than 15% and are uniform across various white matter structures.
Next, the variation of MWF as function of repetition time (TR) was investigated using in vivo MRI data collected at 3.0 T from healthy subjects. These results clearly showed that the measured MWF increased as the TR decreased.
Finally, in order to measure T₁ as well as the rate of magnetization exchange with higher precision, data from bovine brain white matter was collected using a 4.7 T NMR spectrometer. The results from this study clearly showed that the T₁ had two components; therefore magnetization in bovine white matter is not in a fast exchange regime on the T₁ timescale.
16
Sacho, Raphael Hillel. "Brain temperature, inflammation and outcome after severe traumatic brain injury". Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503675.
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Lindström, Lena. "Deep Brain Stimulation Improves Brain Efficiency in Essential Tremor Patients". Thesis, Umeå universitet, Institutionen för psykologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-136866.
Testo completoAbstract (sommario):
The movement disorder essential tremor can be treated with deep brain stimulation (DBS), where electric current is delivered to deep brain structures through permanently implanted electrodes. In this study, brain activity during working memory performance was measured with functional magnetic resonance imaging in thirteen essential tremor patients with DBS in caudal Zona incerta, a diencephalic nucleus. With active stimulation less exertion of certain working memory areas was required to achieve the same level of performance in a manipulation and a maintenance-type working memory task. At the same time, a relatively higher activation was reached for the more demanding manipulation task. These results indicate that DBS can make the brains of tremor patients more efficient in working memory tasks, in accordance with the “efficiency hypothesis” proposed by Nyberg et al. (2014).Rörelsestörningen essentiell tremor kan behandlas med djup hjärnstimulering (DBS), vid vilken elektrisk ström tillförs djupa hjärnstrukturer genom permanent inopererade elektroder. I den här studien mättes hjärnaktivering under arbetsminnesbelastning med funktionell magnetresonans-tomografi hos tretton essentiell tremor-patienter med DBS i kaudala Zona incerta, en kärna i mellanhjärnan. Med stimuleringen påslagen krävdes en lägre hjärnaktivering i arbetsminnes-relaterade områden för att nå samma resultat i två arbetsminnesuppgifter där den enda krävde manipulation och den andra enbart kvarhållande av information. Samtidigt kunde en relativt sett högre aktiveringsnivå uppnås för den mer krävande manipulationsuppgiften. De här resultaten tyder på att DBS kan göra tremorpatienters hjärna mer effektiv i arbetsminnesuppgifter, i enlighet med den “effektivitetshypotes” som lagts fram av Nyberg m fl (2014).
18
Tore, Aas Alf. "Experimental brain tumor metabolism and therapy". Lund, Sweden : Dept. of Neurosurgey, University Hospital, 1994. http://books.google.com/books?id=4XlrAAAAMAAJ.
Testo completo
19
Borta, Oxana. "Brain Drain Controversy". Thesis, Linköping University, Department of Management and Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8370.
Testo completoAbstract (sommario):
This thesis focuses on the widely acknowledged so-called brain drain controversy. More concretely on developments in the traditional brain drain literature towards a new shift, claiming the brain gain effect, as an alternative to the brain drain effect, that emigration may bring to a source country. The research investigates not only the obvious direct loss effects – the so called brain drain – but also the possibility of more subtle indirect beneficial effects.
20
Novales-Li, Philipp. "Human brain acetylcholinesterase". Thesis, University of Oxford, 1993. https://ora.ox.ac.uk/objects/uuid:8f0d7a87-9df9-40be-89a5-bc9953f27f03.
Testo completoAbstract (sommario):
Procedures for the preparative purification of human acetylcholinesterase (AChE; EC 3.1.1.7) have been examined. Chromatofocussing showed caudate nucleus and cerebrospinal fluid (CSF) AChE eluting between isoelectric points (pi) of 5.2 - 5.57, whilst isoelectric focussing (IEF) revealed heterogeneous AChE isoforms migrating between pI 4.5 - 6. Affinity chromatography proved to be better in yielding highly pure samples. The ligands used were either acridinium or procainamide, which yielded brain AChE recoveries of 10.1% and 42.8%, respectively. Various other methods were used such as gel filtration and ion-exchange chromatography on a Pharmacia SMART System. Purified brain AChE was used as antigen to generate anti-AChE monoclonal antibodies (mAbs) by in vivo immunization. BMS-3E4, -7G10, and -9F4 reacted with erythrocyte (G2) AChE, whilst BMS-6D6 bound to brain (G4) AChE in dot blot, titration, and sedimentation experiments. Conversely, the four mAbs recognized only the G4 form and not the G2 form on immunoblotted IEF and non-denaturing Clarke gels. Deglycosylation studies suggest that the four mAbs recognize a carbohydrate epitope linked to AChE. As a preparative step, tissue culture media containing these mAbs were ammonium sulphate precipitated and purified on a gel filtration column. Under reducing conditions, two bands migrating at 80 and 25 kDa were seen, corresponding to the heavy and light chains of Immunoglobulin M (IgM). Four additional mAbs were raised by the novel method of in vitro immunization, using a synthetically-produced C-terminus peptide as antigen. BMS-5, -6, -7, and -8 are all IgMs which recognize soluble brain and not erythrocyte nor membrane-bound AChE in dot blots, IEF, and sedimentation analyses. Although immunocytochemistry of the above-mentioned mAbs did not demonstrate any positive cholinergic binding, the present mAbs may still offer potential clinical and biochemical applications.
21
O'Callaghan, Christopher. "Brain ependymal cilia". Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/29574.
Testo completoAbstract (sommario):
Densely ciliated ependymal cells line the ventricular surface of the brain, cerebral aqueduct, and the central canal of the spinal cord and beat continuously at up to 40Hz. Methodologies for the measurement and the containment of ependymal cilia were developed to allow their study in an ex-vivo setting. Three methods were used to measure ciliary beat frequency, the photomultiplier, photodiode and high speed imaging were established and compared. The method used, to hold ciliated ependymal strips affected ependymal ciliary beat frequency. Tissue held in a microscope cover glass system, or under direct observation of a water immersion lens, showed a beat frequency of half that of cilia observed in an incubation chamber using an inverted microscope. The incubation system, using an inverted microscope, and high speed video system were chosen for the studies in this thesis. Thes results obtained using this system may be summarised as follows:; there was no change in ciliary length or beat frequency between ependyma from infant and adult Wistar rats. However, ependymal cilia beat twice as fast as respiratory cilia. a pH of less than 7 was associated with dramatic fall in ciliary beat frequency which was shown to be directly related to changes in intracellular pH. increasing viscosity decreased ciliary beat frequency, though cilia demonstrated a capability to adapt to an increasing viscous load. pentobarbitone only slowed cilia at levels which were incompatible with life. Halothane, a volatile anaesthetic, caused significant, but reversible ciliary slowing at concentrations which are used in a clinical setting. adrenergic agents and forskolin had no effect on ependymal ciliary function. ethanol and acetaldehyde had no effect on ependymal ciliary beat frequency. low concentrations of the toxin MAM, thought to be implicated in the development of Parkinsonism, caused ciliary slowing.
22
Veen, Frederik Martin van der. "Heart-brain communication". [S.l. : [Groningen] : s.n.] ; [University Library Groningen] [Host], 1997. http://irs.ub.rug.nl/ppn/159417449.
Testo completoAbstract (sommario):
Proefschrift Rijksuniversiteit Groningen.Auteursnaam op omslag: Freddy van der Veen. Kop titelpagina vermeldt: Rijksuniversiteit Groningen. Datum laatste controle: 02-07-1997. Met lit. opg. - Met een samenvatting in het Nederlands.
23
Liu, Arthur K. (Arthur Kuang-Chung). "Spatiotemporal brain imaging". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8963.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2000.Includes bibliographical references.
Understanding how the human brain works, in both health and disease, requires data with both high spatial and temporal resolution. This thesis develops and applies a spatiotemporal neuroimaging method. I describe a linear estimation inverse approach, which is a method for the combination of functional magnetic resonance imaging (fMRI) with electroencephalography (EEG) and magnetoencephalography (MEG). fMRI provides millimeter spatial resolution, while EEG and MEG provide millisecond temporal resolution. The thesis is divided into two broad sections: Monte Carlo modeling studies and experimental studies. Improvements to both the bioelectromagnetic forward and inverse solutions are demonstrated. Through modeling studies, I characterize the accuracy of the method with and without functional and anatomic constraints, the effects of various model mis-specifications, and as a function of EEG/MEG sensor configuration. I describe a noise sensitivity normalization to the traditional linear estimation operator that improves the point spread function (a measure of spatial resolution), increases the spatial homogeneity of the point spread, and allows interpretation of the localization in terms of a statistical measure (F-statistic). Using experimentally generated current dipoles implanted an epilepsy patient, I examine the accuracy of both a realistic and spherical EEG head model. This experimental data demonstrates the improved accuracy of the realistic head model, and gives us confidence in using this realistic head model for EEG source localization. The optimized and validated forward and inverse methods are then applied to a variety of empirical measurements. First, the combined multi modality imaging approach is used to simultaneous EEG/fMRI measurements of a visual stimulus, demonstrating the feasibility of measuring and localizing simultaneously acquired electric potential and hemodynamic measurements. Second, combined MEG/fMRI measurements are used to analyze the spatiotemporal characteristics of a cortical network that is responsive to visual motion coherency. Finally, in epilepsy patients, I compare the non-invasive MEG localization of interictal spikes with verification from invasive recordings and surgical results. These studies, in both normal volunteers and patients, clearly demonstrate the utility, accuracy, and power of the combined use of fMRI, EEG and MEG. The tools demonstrated here provide "real time movies" of the human brain at work during a given task or behavior. This information is required to develop computational models of how the human brain/mind works.
by ARthur K. Lui.
Ph.D.
24
Griffin, Velda L. "Right Brain Study". UNF Digital Commons, 1985. http://digitalcommons.unf.edu/etd/24.
Testo completoAbstract (sommario):
The purpose of this study is to show that instructional methods designed for right-brained students will make a significant difference in the reading achievement scores of the students when compared with the scores of right-brained sixth grade students not receiving these instructional methods.The subjects were sixth grade students who use the right hemisphere of the brain to a greater degree than the left hemisphere. The subjects' cerebral preference was determined by a test known as the Cerebral Preference Index (CPI). Ten students each were chosen from two sixth grade classes. The study consisted of a Control Group and Experimental Group. During the study the Control Group received eight weeks of the regular school's program while the Experimental Group received eight weeks of instructional strategies that take hemispheric specialization into consideration. The results indicated that there was no significant difference in the reading achievement scores of those students who received the instructional methods designed for right brained students. The analysis of data did suggest that those scoring high on the pre-test scored high on the post test. The results indicated the same outcome for low scorers.
25
Parkhomenko, Y. "Power of brain". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46890.
Testo completoAbstract (sommario):
Imagine turning on the music and writing a book just through a
thought or disabled people who can feel, control their limbs or even
communicate with others. We live in the digital age, so there is no surprise
that last technology achievements allow us to make science fiction reality.
26
Sirobaba, N. S., e D. O. Marchenko. "Brain-computer interface". Thesis, Вид-во СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/22533.
Testo completoAbstract (sommario):
A brain–computer interface (BCI), sometimes called a direct neural interface or a brain–machine interface (BMI), is a direct communication pathway between the brain and an external device. BCIs are often aimed at assisting, augmenting or repairing human cognitive or sensory-motor functions.
The field of BCI has advanced mostly toward neuroprosthetics applications that aim at restoring damaged hearing, sight and movement. Thanks to the remarkable cortical plasticity of the brain, signals from implanted prostheses can, after adaptation, be handled by the brain like natural sensor or effector channels. Following years of animal experimentation, the first neuroprosthetic devices implanted in humans appeared in the mid-nineties.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/22533
27
Shliahetskiy, A. A. "Brain - computer interface". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46934.
Testo completoAbstract (sommario):
Brain -computer interface - the interface that implements the
connection between the human brain and the computer. The main idea is
that when you think about action and do it, the same part of the brain is
activated.In the middle of the XIX century, Emil Du Bois- Reymond
showed the relationship between electric current and nerve impulses; in
1875. Richard ketone managed to register the electrical activity of the brain
of animals. The psychiatrist Hans Berger in 1924 invented a method to
record the electrical activity of the human brain. In 1967, psychiatrist
Edmond Dewan published a paper in which he described
the experiment where a man was trying to send a message
to electroencephalogram by means of dot-and-dash,using brain
activity.One of the first practically implemented IMC is
considered a virtual keyboard made by Farwell and Donchyn which
was created in 1988.
28
Almeida, Luís Filipe Martinho de. "Brain computer interface". Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21618.
Testo completoAbstract (sommario):
Mestrado em Engenharia Eletrónica e TelecomunicaçõesA investigação e desenvolvimento de sistemas BCI, Brain Computer Interface tem crescido de ano para ano, com resultados cada vez melhores. Uma das principais vertentes para a qual estes sistemas têm sido usados é na área da neuroprostética. Desta forma tem-se demonstrado em vários estudos e investiga ções a possibilidade de controlar membros completos ou parciais robóticos por nós seres humanos, dando assim uma liberdade e conquista de movimentos perdidos a pessoas incapacitadas. No entanto uma grande parte dos melhores resultados obtidos envolve a utilização de BCI invasivos, o que necessita de ser implantado diretamente no cérebro humano, através de uma operação cirúrgica. Isto é ainda um dos grandes inconvenientes que esta abordagem implica e também o facto de uma grande parte destes estudos ainda estarem na fase de testes. Este trabalho teve como objetivo tentar comprovar que os BCI não invasivos também conseguem obter bons resultados apesar das suas limitações e pior aquisição de resultados devido à inclusão de ruído por parte do nosso crânio e cabelo, assim como a inclusão dos Parâmetros Hjorth proporciona melhores resultados na identificação das classes desejadas. Dividiu-se o trabalho em duas partes, uma para a identificação das classes de “Piscar de Olho” e outra para identificação das classes de “Ações Pensadas” . Os resultados foram todos obtidos tendo em conta apenas um utilizador. Relativamente à deteção do “Piscar de Olho” comprovou-se que ́e facilmente conseguido com resultados quase perfeitos, com uma precisção de 99 . 98%. Relativamente à deteção de “Ações Pensadas” não foi possível comprovar a sua deteçãao usando sessções de gravação diferentes, no entanto verificou-se que a classificação das classes tendo em conta a mesma sessão de gravação, obtém resultados muito bons com valores acima dos 99% para o melhor m ́etodo preditivo. A inclusão dos Parâmetros Hjorth foi em todos os casos de estudo, a opção em que os resultados foram sempre melhores, demonstrando assim que a inclusão dos mesmos é uma opção aconselhável, pois em alguns casos, a precisão na deteção das classes aumento para duas ou mais vezes. Os resultados são promissores e apesar de não ter conseguido obter os melhores resultados para sessões de gravação independentes na classificação de “Ações Pensadas” , indico nas análises os passos necessáios para a obtenção de melhores resultados e a possibilidade de generalização do processo para diversos utilizadores.
The research and development of BCI systems, Brain Computer Interface has grown from year to year, with better and better results. One of the main areas for which these systems have been used is the neuroprosthetic. Several studies and investigations have shown the possibility of controlling complete or partial robotic members by people, thus giving a freedom and conquest of lost movements to incapacitated persons. However, a great part of the best results obtained involves the use of invasive BCI, which needs to be implanted directly into the human brain through a sirurgical operation. This is still one of the great drawbacks that this approach entails and also the fact that a large part of these studies are still in the testing phase. The aim of this study was to try and prove that non-invasive BCI can also achieve good results despite their limitations and inferior quality on the acquisition of data due to the inclusion of noise from our skull and hair, and also that the inclusion of the Hjorth Parameters on the analysis provides better results in identifying the desired classes. The work was split into two parts, one for the identification of “Eye Blinking” classes and the other for “Thought Actions” classes. The results were all obtained with only one user in mind. Regarding the detection of “Eye Blinking” it has been found that it is easily achieved with near-perfect results, with an accuracy of 99 . 98%. Regarding the detection of “Thought Actions” it was not possible to verify its detection using different recording sessions, however it was verified that the classification of classes taking into account the same recording session, obtains very good results with values above 99% for the best predictive method. The inclusion of Hjorth Parameters was in all study cases, the option in which the results were always better, thus demonstrating that their inclusion is an advisable option, since in some cases, the accuracy in detecting classes doubled or more. The results are promising and although I haven’t been able to obtain the best results for independent recording sessions in the classification of “Thought actions” , I indicate in the analysis some steps necessary to obtain better results and the possibility of generalizing the process for several users.
29
Bhuta, Dimple. "Brain Controlled Switch". VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/2795.
Testo completoAbstract (sommario):
This study aims at designing and implementing a single channel stand-alone Brain-Controlled Switch (BCS) device, which records the electroencephalography (EEG) signals from the scalp using electrodes, amplifies it, eliminates interferences (associated with the EEG signals) and processes the EEG signals to extract and decode temporal signal features to determine user’s intention of regulating an external switch. The design of our “brain-controlled switch” device is implemented using a bio-potential amplifier and a microcontroller. The bio-potential amplifier amplifies the EEG signals to a level sufficient for processing, eliminates interferences and ensures patient safety. The microcontroller (dsPIC30F4013) digitizes the amplified and conditioned analog EEG signals from the bio-potential amplifier, extracts the desired signal features for decoding and prediction of user’s intention and accordingly operates the external switch. When the user concentrates on an external visual stimulus or performs externally triggered movement (hand movement or motor imagery movement), a reproducible pattern appears in user’s EEG frequency bands. The analysis of these patterns is used to decode and predict user’s intention to operate an external switch. To realize our “brain-controlled switch”, we explored two EEG sources: steady-state visually evoked potentials (SSVEP) and beta rebounds, which are patterns generated in the EEG frequency bands associated with focusing on an external visual stimulus or performing externally triggered movements. In case of SSVEP based brain controlled switch, a repetitive visual stimulus (LED flickering at a specified frequency) was used. When the user concentrates on the flickering LED, a dominant fundamental frequency (equivalent to the flickering frequency) appears in the spectral representation of the EEG signals recorded at occipital lobes. Our microcontroller implemented a digital band pass filter to extract the frequency band containing this fundamental frequency and continuously took an average of the amplitude power every predetermined time interval. Whenever the amplitude average power exceeded the preset power threshold the external switch was turned ON. A healthy subject participated in this study, and it took approximately 3.14 ± 1.81 seconds of active concentration for the subject to turn ON the switch in real time with a false positive rate of 1.17%. In case of beta rebound based brain controlled switch, the subject was instructed to perform a brisk hand movement following an external synchronization signal. Our design focused on the post-movement beta rebound which occurs after the cessation of the movement to operate the external switch. Our microcontroller in this case implemented a digital band pass filter to extract the beta band and continuously took an average of its amplitude power every predetermined time interval. Whenever the amplitude average power exceeded the preset power threshold the external switch was turned ON. It took approximately 12.23 ± 7.39 seconds of active urging time by the subject to turn ON the switch in real time with a false positive rate of 9.33%. Thus we have designed a novel stand-alone BCS device which operates an external switch by decoding and predicting user’s intentions.
30
Malkus, Amy J. "Adolescent Brain Development". Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/4314.
Testo completo
31
Klempin, Friederike Claudia. "Adult brain plasticity". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15844.
Testo completoAbstract (sommario):
Der Hippocampus ist eine von zwei Gehirnregionen, in der zeitlebens kontinuierlich neue Nervenzellen gebildet werden. Er spielt eine wichtige Rolle bei der Gedächtniskonsolidierung und wird mit der funktionellen Entstehung neurodegenerativer Erkrankungen in Verbindung gebracht. Strukturveränderungen im erwachsenen Gehirn, die mit einer Depression einhergehen, sind laut Literatur auf einen geringen Serotoninspiegel und reduzierte hippocampale Neurogenese zurückzuführen. Selektive Serotonin-Wiederaufnahmehemmer (SSRI) erhöhen die Serotoninkonzentration im synaptischen Spalt und üben einen positiven Effekt auf die adulte Neurogenese aus. In der vorliegenden Arbeit wird untersucht, wie Veränderungen in der Serotonin (5-HT)-Neurotransmission durch einmalige oder chronische Gaben von Fluoxetin und speziellen Agonisten und Antagonisten für die Serotoninrezeptoren 5-HT1a und 5-HT2 in der erwachsenen Maus die Proliferation und Differenzierung von neugebildeten Nervenzellen im Gyrus dentatus beeinflussen. Die Ergebnisse zeigen, dass ein konträres Agieren beider Rezeptoren zu einem ausgewogenen Serotoninspiegel führt. 5-HT1a- und 5-HT2c-Rezeptoren haben einen Einfluss auf das Überleben neugebildeter Nervenzellen, wobei sie unterschiedliche Entwicklungsstadien innerhalb der adulten Neurogenese kontrollieren. Die vorliegende Arbeit bekräftigt außerdem, dass die chronische Gabe von Fluoxetin die adulte Neurogenese steigert.The hippocampus as one region with ongoing neurogenesis throughout life contributes to the formation of long-term memory and has also been implicated in the pathology of major depression. Studies suggest that depression might be due to decreased levels of serotonin and reduced neurogenesis in the adult brain and that the beneficial effects of selective serotonin reuptake inhibitors would require adult hippocampal neurogenesis. Here, I investigated how modulation of serotonergic neurotransmission by acute and chronic treatment with the antidepressant fluoxetine, and selective serotonin receptor agonists and antagonists in adult mice influences precursor cell activity during development. I focused on 5-HT1a and 5-HT2 receptors as major mediators of serotonin action. The present findings suggest that an opposed action of 5-HT1a and 5-HT2c receptor subtypes result in a balanced regulation of serotonin levels in the dentate gyrus. Both receptors differentially affect intermediate cell stages in adult hippocampal neurogenesis and play an important role in the survival of newly generated neurons. Furthermore, this study confirms that chronic fluoxetine treatment increases adult neurogenesis. In conclusion, the latency of onset of fluoxetine action can be explained by a balanced interplay of 5-HT1a and 5-HT2c receptor subtypes.
32
Khan, Muhammad S. "Design and Development of Smart Brain-Machine-Brain Interface (SBMIBI) for Deep Brain Stimulation and Other Biomedical Applications". FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2724.
Testo completoAbstract (sommario):
Machine collaboration with the biological body/brain by sending electrical information back and forth is one of the leading research areas in neuro-engineering during the twenty-first century. Hence, Brain-Machine-Brain Interface (BMBI) is a powerful tool for achieving such machine-brain/body collaboration. BMBI generally is a smart device (usually invasive) that can record, store, and analyze neural activities, and generate corresponding responses in the form of electrical pulses to stimulate specific brain regions. The Smart Brain-Machine-Brain-Interface (SBMBI) is a step forward with compared to the traditional BMBI by including smart functions, such as in-electrode local computing capabilities, and availability of cloud connectivity in the system to take the advantage of powerful cloud computation in decision making.
In this dissertation work, we designed and developed an innovative form of Smart Brain-Machine-Brain Interface (SBMBI) and studied its feasibility in different biomedical applications. With respect to power management, the SBMBI is a semi-passive platform. The communication module is fully passive—powered by RF harvested energy; whereas, the signal processing core is battery-assisted. The efficiency of the implemented RF energy harvester was measured to be 0.005%.
One of potential applications of SBMBI is to configure a Smart Deep-Brain-Stimulator (SDBS) based on the general SBMBI platform. The SDBS consists of brain-implantable smart electrodes and a wireless-connected external controller. The SDBS electrodes operate as completely autonomous electronic implants that are capable of sensing and recording neural activities in real time, performing local processing, and generating arbitrary waveforms for neuro-stimulation. A bidirectional, secure, fully-passive wireless communication backbone was designed and integrated into this smart electrode to maintain contact between the smart electrodes and the controller. The standard EPC-Global protocol has been modified and adopted as the communication protocol in this design. The proposed SDBS, by using a SBMBI platform, was demonstrated and tested through a hardware prototype. Additionally the SBMBI was employed to develop a low-power wireless ECG data acquisition device. This device captures cardiac pulses through a non-invasive magnetic resonance electrode, processes the signal and sends it to the backend computer through the SBMBI interface. Analysis was performed to verify the integrity of received ECG data.
33
Anderalm, Ida. "Human Being or Human Brain? : Animalism and the Problem of Thinking Brains". Thesis, Umeå universitet, Institutionen för idé- och samhällsstudier, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-122886.
Testo completoAbstract (sommario):
Animalismens huvudargument säger att du är det tänkande objektet som sitter i din stol, och enligt animalisterna själva innebär detta att du är identisk med ett mänskligt djur. Argumentet är dock problematiskt då det inte tycks utesluta eventuella tänkande delar hos det mänskliga djuret, som till exempel dess hjärna. Detta beror på att hjärnor också kan beskrivas som tänkande, samt att även de befinner sig inom det spatiella område som upptas av det mänskliga djuret. I den här uppsatsen argumenterar jag för att tänkande hjärnor är ett problem för animalismen och att tesen att vi är identiska med hjärnor är ett verkligt hot mot den animalistiska teorin om personlig identitet. Olika argument som lagts fram mot tesen att vi är hjärnor avhandlas, som till exempel att hjärnor inte existerar och att hjärnor inte tänker. Jag diskuterar även två argument som tidigare använts för att visa att vi är personer snarare än mänskliga djur (the Transplant Intuition och the Remnant Person Problem), men i det här sammanhanget bedöms de utifrån deras förmåga att stödja hjärnteorin.
34
Abou, Elseoud A. (Ahmed). "Exploring functional brain networks using independent component analysis:functional brain networks connectivity". Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526201597.
Testo completoAbstract (sommario):
Abstract Functional communication between brain regions is likely to play a key role in complex cognitive processes that require continuous integration of information across different regions of the brain. This makes the studying of functional connectivity in the human brain of high importance. It also provides new insights into the hierarchical organization of the human brain regions. Resting-state networks (RSNs) can be reliably and reproducibly detected using independent component analysis (ICA) at both individual subject and group levels. A growing number of ICA studies have reported altered functional connectivity in clinical populations. In the current work, it was hypothesized that ICA model order selection influences characteristics of RSNs as well as their functional connectivity. In addition, it was suggested that high ICA model order could be a useful tool to provide more detailed functional connectivity results. RSNs’ characteristics, i.e. spatial features, volume and repeatability of RSNs, were evaluated, and also differences in functional connectivity were investigated across different ICA model orders. ICA model order estimation had a significant impact on the spatial characteristics of the RSNs as well as their parcellation into sub-networks. Notably, at low model orders neuroanatomically and functionally different units tend to aggregate into large singular RSN components, while at higher model orders these units become separate RSN components. Disease-related differences in functional connectivity also seem to alter as a function of ICA model order. The volume of between-group differences reached maximum at high model orders. These findings demonstrate that fine-grained RSNs can provide detailed, disease-specific functional connectivity alterations. Finally, in order to overcome the multiple comparisons problem encountered at high ICA model orders, a new framework for group-ICA analysis was introduced. The framework involved concatenation of IC maps prior to permutation tests, which enables statistical inferences from all selected RSNs. In SAD patients, this new correction enabled the detection of significantly increased functional connectivity in eleven RSNsTiivistelmä Toiminnallisten aivoalueiden välinen viestintä on todennäköisesti avainasemassa kognitiivisissa prosesseissa, jotka edellyttävät jatkuvaa tiedon integraatiota aivojen eri alueiden välillä. Tämä tekee ihmisaivojen toiminnallisen kytkennällisyyden tutkimuksesta erittäin tärkeätä. Kytkennälllisyyden tutkiminen antaa myös uutta tietoa ihmisaivojen osa-alueiden välisestä hierarkiasta. Aivojen hermoverkot voidaan luotettavasti ja toistettavasti havaita lepotilan toiminnasta yksilö- ja ryhmätasolla käyttämällä itsenäisten komponenttien analyysia (engl. Independent component analysis, ICA). Yhä useammat ICA-tutkimukset ovat raportoineet poikkeuksellisia toiminnallisen konnektiviteetin muutoksia kliinisissä populaatioissa. Tässä tutkimuksessa hypotetisoitiin, että ICA:lla laskettaujen komponenttien lukumäärä (l. asteluku) vaikuttaa tuloksena saatujen hermoverkkojen ominaisuuksiin kuten tilavuuteen ja kytkennällisyyteen. Lisäksi oletettiin, että korkea ICA-asteluku voisi olla herkempit tuottamaan yksityiskohtaisia toiminnallisen jaottelun tuloksia. Aivojen lepotilan hermoverkkojen ominaisuudet, kuten anatominen jakautuminen, volyymi ja lepohermoverkkojen havainnoinnin toistettavuus evaluoitin. Myös toiminnallisen kytkennällisyyden erot tutkitaan eri ICA-asteluvuilla. Havaittiin että asteluvulla on huomattava vaikutus aivojen lepotilan hermoverkkojen tilaominaisuuksiin sekä niiden jakautumiseen alaverkoiksi. Pienillä asteluvuilla hermoverkojen neuroanatomisesti erilliset yksiköt pyrkivät keräytymään laajoiksi yksittäisiksi komponenteiksi, kun taas korkeammilla asteluvuilla ne havaitaan erillisinä. Sairauksien aiheuttamat muutokset toiminnallisessa kytkennällisyydessä näyttävät muuttuvan myös ICA asteluvun mukaan saavuttaen maksiminsa korkeilla asteluvuilla. Korkeilla asteluvuilla voidaan havaita yksityiskohtaisia, sairaudelle ominaisia toiminnallisen konnektiviteetin muutoksia. Korkeisiin ICA asteluvun liittyvän tilastollisen monivertailuongelman ratkaisemiseksi kehitimme uuden menetelmän, jossa permutaatiotestejä edeltävien itsenäisten IC-karttoja yhdistämällä voidaan tehdä luotettava tilastollinen arvio yhtä aikaa lukuisista hermoverkoista. Kaamosmasennuspotilailla esimerkiksi kehittämämme korjaus paljastaa merkittävästi lisääntynyttä toiminnallista kytkennällisyyttä yhdessätoista hermoverkossa
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Purins, Karlis. "Brain Tissue Oxygenation in Traumatic Brain Injury : Experimental and Clinical Studies". Doctoral thesis, Uppsala universitet, Neurokirurgi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-195867.
Testo completoAbstract (sommario):
Traumatic brain injury (TBI) is a major cause of death and disability. TBI is frequently followed by cerebral ischemia which is a great contributor to secondary brain damage. The main causes of cerebral ischemia are pathophysiological changes in cerebral blood flow and metabolism. Treatment of TBI patients is currently based on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) targeted treatment protocols. However, ICP and CPP alone do not provide information of the oxygen availability in the brain. Monitoring of brain tissue oxygenation (BtipO2) may give additional and valuable information about the risk for development of ischemia in TBI patients. The aims of this thesis were to study BtipO2 monitoring devices in-vitro regarding accuracy and stability, to detect threshold level of cerebral ischemia in-vivo and finally to examine the cerebral oxygen levels and cerebral metabolism in TBI patients. The BtipO2 probes performed with high accuracy and stability at different clinically relevant oxygen concentrations. A pig TBI model was developed by step-wise intracranial volume/pressure increase. Volume increase resulted in a gradual increased ICP, decreased CPP, intracranial compliance and BtipO2, respectively. Brain death (BD) was confirmed by negative CPP and negligible amount of previously injected microspheres in the brain tissue. The model simulated the clinical development of BD in humans with a classical pressure-volume response and systemic cardiovascular reactions. The model should be suitable for studies of brain injury mechanisms. From the same in-vivo model it was also possible to detect the threshold level of cerebral ischemia in the pig, where BtipO2 below 10 mmHg and CPP below 30 mmHg was associated with an impaired cerebral metabolism (microdialysis lactate to pyruvate ratio >30). BtipO2 together with cerebral microdialysis were studied in 23 severe TBI patients. We observed different patterns of changes in BtipO2 and cerebral microdialysis biomarkers in focal and diffuse TBI. Increased cerebral microdialysis levels of glutamate, glycerol or the lactate/pyruvate ratio were observed at BtipO2 < 5 mmHg, indicating increased vulnerability of the brain at this critical level of tissue oxygenation in TBI patients.
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Androutsellis-Theotokis, Andreas. "The release and distribution of brain derived neurotrophic factor in brain". Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266203.
Testo completo
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Kunanandam, Visakasuntharam. "Reverse flow of brain interstitial fluid through venular blood-brain barrier". Thesis, University of Hull, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363207.
Testo completo
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Kinnunen, K. M. "Traumatic brain injury : relationships between brain structural abnormalities and cognitive function". Thesis, Goldsmiths College (University of London), 2011. http://research.gold.ac.uk/6498/.
Testo completoAbstract (sommario):
Traumatic brain injury (TBI) is the leading cause of disability in young adults and a major public health problem. Persistent cognitive impairments are common, and constitute a significant source of long-term disability. The specific pathophysiological mechanisms underlying these impairments remain poorly understood. As it disconnects brain networks, white matter damage can be a key determinant of cognitive impairment after TBI. Neuroimaging and neuropsychological methods were employed to explore the relationships between indices of brain structure and cognitive function. The participants were 40 TBI patients and 40 healthy controls. First, relationships between focal lesions and cognitive performance were investigated using structural magnetic resonance imaging (MRI) and a battery of neuropsychological tests. The results demonstrated that lesion location and load are not good indices of the cognitive deficits - probably because diffuse axonal injury is poorly assessed by standard MRI. By contrast, diffusion tensor imaging (DTI) can be used to quantify the microstructure of white matter. A ‘whole-brain’ technique, tract-based spatial statistics (TBSS), was used to flexibly analyse the structure of white matter tracts. Despite only small amounts of focal damage observed using standard MRI, TBSS revealed widespread white matter abnormalities after TBI. White matter damage was found in patients with no evidence of focal damage, and in patients classified as ‘mild’ clinically. Relationships between white matter tract structure and specific cognitive functions were then explored. The structure of the fornix, an important white matter pathway of the hippocampus, correlated with verbal associative memory across the patient and control groups. By contrast, structure of frontal lobe connections showed distinct relationships with executive function in these two groups. The results emphasise the importance of white matter pathology after TBI and suggest that disruption to specific white matter tracts is associated with particular patterns of cognitive impairment, but also highlight the complexity of these relationships.
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Doria, Valentina. "Spontaneous brain activity in the developing brain : a functional MRI study". Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543346.
Testo completo
40
Chen, Tzu-Ying. "Brain bioavailability of polyphenols| Implications for delivery of brain health benefits". Thesis, Purdue University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3612949.
Testo completoAbstract (sommario):
Consumption of fruits and vegetables has been associated with neuroprotection and cognitive benefits throughout the life span. These associations have sparked interest in plant-derived polyphenols as biologically active agents with potential for targeting brain benefits. However, little is known regarding the ability of the polyphenols or their metabolites from polyphenol-rich products to cross the blood-brain-barrier, and be available for biological action. Furthermore, additional insight is needed on factors affecting the absorption and brain distribution of polyphenol metabolites in vivo. To fill gap in current knowledge, this thesis will focus on the effects of diabetogenic diet and diabetic state which have been considered potential risk factors for neurodegenerative disease on polyphenol bioavailability from a 'Standardized Grape Polyphenol' (grape seed extract, Concord grape juice and resveratrol). Additionally, this thesis will provide novel evidence on plasma pharmacokinetics and regional brain distribution of polyphenol metabolites from apple/grape seed and bilberry extracts in a weaning piglet model.
We have found that background diabetogenic diet had limited effects on polyphenol plasma levels and brain bioavailability in a healthy Sprague-Dawley rat model. However, the diabetic state negatively influenced polyphenol metabolite levels in plasma and brain tissues, possibly in part, due to excessive excretion in urine. By using a young piglet model, we determined plasma pharmacokinetics of polyphenol metabolites using physiological and pharmacological doses of apple/grape seed and bilberry extracts. We found that in a physiological dose achievable by supplementation, polyphenol metabolites were able to cross blood-brain barrier to deposit in the brain. There was a difference in regional brain deposition with cerebellum being a preferred site for accumulation. Our data warrant the future design of functional tests on aging-related diseases, specifically Alzheimer's disease as well as improvement in cognitive and memory in healthy infant/child model.
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Skopin, Mark D. "The Induction of Traumatic Brain Injury by Blood Brain Barrier Disruption". University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1302125115.
Testo completo
42
Kawamoto, Yasuhiro. "Immunohistochemical localization of brain-derived neurotrophic factor in adult rat brain". Kyoto University, 1997. http://hdl.handle.net/2433/202181.
Testo completo
43
Jonasson, Lars. "Aerobic fitness and healthy brain aging : cognition, brain structure, and dopamine". Doctoral thesis, Umeå universitet, Diagnostisk radiologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-139056.
Testo completoAbstract (sommario):
Background: Performing aerobic exercise and maintaining high levels of aerobic fitness may have positive effects on both brain structure and function in older adults. Despite decades of research however, there is still a rather poor understanding of the neurocognitive mechanisms explaining the positive effects of aerobic exercise on cognition. Changes in prefrontal gray matter as well as dopaminergic neurotransmission in striatum are both candidate neurocognitive mechanisms. The main aims of this thesis are: 1. To investigate the effects of aerobic exercise and fitness on cognition and magnetic resonance imaging (MRI) derived gray matter volumes using data from a 6 month physical exercise intervention in older adults (Study I). 2. To simulate the effect of atrophy in longitudinal positron emission tomography (PET) which could pose a challenge to interpreting changes in longitudinal PET imaging (Study II). 3. To study the influence of aerobic exercise and fitness on the dopamine D2-receptor (D2R) system in striatum using [11C]raclopride PET as a potential mechanism for improved cognition (Study III). Results: In Study I, aerobic exercise was found to improve cognitive performance in a broad, rather than domain-specific sense. Moreover, aerobic fitness was related to prefrontal cortical thickness, and improved aerobic fitness over 6 months was related to increased hippocampal volume. In Study II, we identified areas in the striatum vulnerable to the effect of shrinkage, which should be considered in longitudinal PET imaging. Finally, in Study III, the effect of being aerobically fit, and improving fitness levels was found to impact dopaminergic neurotransmission in the striatum, which in turn mediated fitness-induced improvements in working memory updating performance. Conclusion: The findings in this thesis provide novel evidence regarding the neurocognitive mechanisms of aerobic exercise-induced improvements in cognition, and impacts the interpretation of longitudinal PET imaging. Performing aerobic exercise and staying aerobically fit at an older age have positive effects on cognition and brain systems important for memory and cognition. Specifically, fitness-induced changes to the dopaminergic system stands out as one novel neurocognitive mechanism explaining the positive effects of aerobic fitness on working-memory performance in healthy older adults.
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Keller, Kristen Jo. "Challenges to Secondary Brain Injury Prevention in Severe Traumatic Brain Injury". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/338712.
Testo completoAbstract (sommario):
BACKGROUND/AIMS: Inconsistency in the use of secondary brain injury prevention guidelines among US trauma centers after severe traumatic brain injury is prevalent in many literature sources. However, this phenomenon has not been thoroughly studied. The purpose of this DNP project is to identify the key barriers and challenges in compliance to the evidence-based guidelines for secondary brain injury prevention. DESIGN: An exploratory, emergent design was used to collect descriptive qualitative data through the use of a survey. SETTING: Six Phoenix Metropolitan Level 1 trauma centers. PARTICIPANTS: All survey participants who consented to survey completion, which had greater than six months of experience and directly worked with patients suffering from a severe TBI in the clinical setting. MEASUREMENTS: Participant demographics (work experience, area of work, job title), current awareness and use of Brain Trauma Foundation guidelines, and time duration for evidence based order set implementation. Narrative responses were also used to identify barriers to current use of the BTF guidelines and factors that may promote their use in the future. RESULTS: A total of 43 participants consented to the survey study, with completion by 35 participants. RNs (n=27), Physicians (n=2), NPs or PAs (n=5), with an average work experience of 6 to 14 years (42.86%). A total of n=22 (62%) of participants were unaware of the current BTF guidelines for severe TBI and only 25% (n=9) aware that their facility has a protocol based on the BTF guidelines for severe TBI, while 51% (n=18) were unsure if their facility had a protocol. Barriers were identified in narrative form and were consistent with awareness/education, provider congruence, communication, and order set/protocol process improvement. CONCLUSION: The understanding of current patient management for severe TBI based on the BTF guidelines is sporadic among the greater Phoenix area Level 1 trauma centers. Requiring proof of BTF guidelines compliance by the ACS at time of Level 1 certification may increase the consistent recommended use of the BTF guidelines for the care of severe TBIs.
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Gutierrez, Barragan Daniel. "Brain-wide mapping of fMRI network dynamics in the mouse brain". Doctoral thesis, Università degli studi di Trento, 2018. http://hdl.handle.net/11572/301211.
Testo completoAbstract (sommario):
Intrinsic brain activity has been widely characterized using the blood-oxygen-level-dependent(BOLD) functional Magnetic Resonance Imaging(fMRI)at rest. There is increasing interest in finding reproducible and robust signatures of large-scale brain synchronization, and pinpointing their neurophysiological substrates and inherent alteration in disease.In this respect, the implementation of dynamic fMRI mapping in laboratory animalsrepresents a major advance, offeringthe opportunity to unravel the elusive drivers of this phenomenon via the use of cell-type specific manipulations that are off limits in humans.Multiple investigations have shown that spontaneous brain activity is non-stationary andinvolves reconfigurationsinto multiple dynamicstates.This research describesa series of studies aimedto map spontaneous fMRI (rsfMRI) network dynamics in the resting mouse brain with voxel resolution. Starting from a proof-of-concept demonstration that canonical resting state fMRI correlations are reliably described by brief instances of regional peak fMRI activity, wedevised a novel frame-wise clustering strategy that allowed us to map recurrent fMRI networks states dynamicsin the mouse brain. We showthat brain-wide patterns of fMRI co-activation can be reliably mapped at the group and subject level, defining a restricted set of recurring brain states characterized by rich network structure. Of particular interest was the observation of opposite co-activation of the mouse default mode network (DMN) and Latero-cortical networks(LCN), two systems that have been proposed to parallel analogous systems of the human brain.Importantly, we also document that these functional states are characterized by contrasting patterns of spontaneous fMRI activity,and exhibit coupled oscillatory dynamics embedded in a common temporal reference marked by infra-slow global fMRI signal oscillations. We next applied this novel framework to a genetic modelof autismand show that aberrant patterns of fMRI connectivity in a genetic model of autism reflect the engagement non-canonical brain states, characterized by altered regional topography and oscillatory dynamics. We finally show that pharmacological stimulation of the cholinergic systems results in reduced large-scale brain synchronization, a finding associated with anew set of oscillating statesin which the involvement of basal forebrain areas is pre-dominant. Collectively,our result demonstrate the possibility of mapping spatio-temporal dynamics of spontaneous brain activity in the living mouse brain with voxel resolution. Our approach reveals a new set of fundamental principles guiding the spatiotemporal organization of resting state fMRI activity, and its disruption in brain disorders.
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Gutierrez, Barragan Daniel. "Brain-wide mapping of fMRI network dynamics in the mouse brain". Doctoral thesis, Università degli studi di Trento, 2018. http://hdl.handle.net/11572/301211.
Testo completoAbstract (sommario):
Intrinsic brain activity has been widely characterized using the blood-oxygen-level-dependent(BOLD) functional Magnetic Resonance Imaging(fMRI)at rest. There is increasing interest in finding reproducible and robust signatures of large-scale brain synchronization, and pinpointing their neurophysiological substrates and inherent alteration in disease.In this respect, the implementation of dynamic fMRI mapping in laboratory animalsrepresents a major advance, offeringthe opportunity to unravel the elusive drivers of this phenomenon via the use of cell-type specific manipulations that are off limits in humans.Multiple investigations have shown that spontaneous brain activity is non-stationary andinvolves reconfigurationsinto multiple dynamicstates.This research describesa series of studies aimedto map spontaneous fMRI (rsfMRI) network dynamics in the resting mouse brain with voxel resolution. Starting from a proof-of-concept demonstration that canonical resting state fMRI correlations are reliably described by brief instances of regional peak fMRI activity, wedevised a novel frame-wise clustering strategy that allowed us to map recurrent fMRI networks states dynamicsin the mouse brain. We showthat brain-wide patterns of fMRI co-activation can be reliably mapped at the group and subject level, defining a restricted set of recurring brain states characterized by rich network structure. Of particular interest was the observation of opposite co-activation of the mouse default mode network (DMN) and Latero-cortical networks(LCN), two systems that have been proposed to parallel analogous systems of the human brain.Importantly, we also document that these functional states are characterized by contrasting patterns of spontaneous fMRI activity,and exhibit coupled oscillatory dynamics embedded in a common temporal reference marked by infra-slow global fMRI signal oscillations. We next applied this novel framework to a genetic modelof autismand show that aberrant patterns of fMRI connectivity in a genetic model of autism reflect the engagement non-canonical brain states, characterized by altered regional topography and oscillatory dynamics. We finally show that pharmacological stimulation of the cholinergic systems results in reduced large-scale brain synchronization, a finding associated with anew set of oscillating statesin which the involvement of basal forebrain areas is pre-dominant. Collectively,our result demonstrate the possibility of mapping spatio-temporal dynamics of spontaneous brain activity in the living mouse brain with voxel resolution. Our approach reveals a new set of fundamental principles guiding the spatiotemporal organization of resting state fMRI activity, and its disruption in brain disorders.
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Aida, Toru. "Study of human head impact brain tissue constitutive models /". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1402.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains x, 133 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 122-130).
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Petersson, Susanna. "Megencephaly : significance, biology and identification of a genetic cause /". Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-210-8.
Testo completo
49
Levatino, Antonina. "Brain training - brain draining : skilled migration, student mobility, and transnational higher education". Doctoral thesis, Universitat Pompeu Fabra, 2016. http://hdl.handle.net/10803/392604.
Testo completoAbstract (sommario):
The cross-border mobility of educational services, commonly known as transnational higher education (TNHE), represents an important dimension of the internationalisation of higher education. Its relationship with the mobility of students and graduates has raised interest among scholars from different disciplines, but empirical evidence is rare. This thesis addresses this gap by providing three empirical studies on this issue. Overall, the results indicate that TNHE is not substituting student mobility and suggest that the provision of TNHE can constitute a strategy for developed countries to increase skilled migrants’ and students’ recruitment. The results equally imply that caution should be devoted to these kinds of issues by developing countries when opening their educational market to foreign providers. A range of other findings contribute to a deeper and nuanced understanding of the phenomenon of TNHE. The insights provided can benefit future research both on international migration and higher education.La mobilitat internacional dels serveis educatives, comunament coneguda com l'educació superior transnacional (TNHE), representa un aspecte important de la internacionalització de l'educació superior. La seva relació amb la mobilitat dels estudiants d'educació superior i graduats ha despertat interès entre acadèmics de diferents disciplines. L'evidència empírica és però escassa. Aquesta tesi proporciona tres estudis empírics sobre aquesta qüestió. Els resultats indiquen que la TNHE no està substituint la mobilitat d'estudiants i suggereixen que la provisió de TNHE pot constituir una bona estratègia per els països desenvolupats per atreure més immigrants qualificats i estudiants. Els resultats impliquen igualment que els països en desenvolupament, que obren el seu mercat educatiu als proveïdors estrangers, han de prestar atenció a aquest tipus de possibles conseqüències. Una gamma d'altres resultats contribueixen a una comprensió més profunda i matisada del fenomen de la TNHE. Si proporciona també una sèrie de pistes i reflexions per a futures investigacions.
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Abson, Jeanne Anne. "Grief following brain injury : a validation of the Brain Injury Grief Inventory". Thesis, Bangor University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409238.
Testo completo