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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.
1

The antinociceptive action of the anterior pretectal nucleus

Rees, Huw January 1989 (has links)
No description available.
2

Cerebral imaginaries: brains and literature in the transatlantic sphere, 1800-1880

Schöberlein, Stefan 01 August 2018 (has links)
“Cerebral Imaginaries” examines the intersections between anatomically justified theories of brain function and the literature of Great Britain and the United States from the 1800s to the 1880s. The years that followed the heyday of philosophical mind materialism (in the late 1700s) but preceded the dawn of modern psychology (around 1880), saw the appearance of neuroscience as a discipline. This dissertation traces the literary impact and cultural constructedness of new theories of mindedness and human cognition that came in its wake. What anatomists, alienists, and amateur scientists hypothesized about the brain in these years served to unsettle many assumptions about the thinking self that underpinned Anglo-American culture: be it the idea of having a single, coherent mind, or notions of free will and rationality. In tandem with early neurologists, contemporary writers interrogated what having (or perhaps: being) a brain really entailed, leading to a highly creative cross-insemination between science and literature. From the British Romantics to the American Gothic and from early Realism to technophile periodical fiction, this dissertation demonstrates that literature not only reacted to the science of its day, but, in turn, directly influenced it by providing structuring metaphors, cognitive frameworks, and epistemologies.
3

Diaspora and development

Wei, Yingqi, Balasubramanyam, V.N. 08 November 2009 (has links)
No / Jagdish Bhagwati's proposal for a 'brains tax' to be levied on the incomes of the diaspora from developing countries residing in the developed countries and the proceeds to be remitted to the countries of origin of the diaspora is well known. In recent years the voluntary contributions or remittances from the diaspora to their countries of origin have often been higher than the aid monies given to these countries. It is now increasingly recognised that the diaspora may have an active role to play in the development process of their countries of origin. They are not only a source of funds; they are also a rich source of skills and know-how. This paper analyses the potential of the diaspora as agents of change in their countries of origin and argues that the social rate of return to a unit of diaspora investments may be higher than that for a unit of foreign direct investment from non-diaspora sources.
4

CONTINUOUS TIME MULTI-STATE MODELS FOR INTERVAL CENSORED DATA

Wan, Lijie 01 January 2016 (has links)
Continuous-time multi-state models are widely used in modeling longitudinal data of disease processes with multiple transient states, yet the analysis is complex when subjects are observed periodically, resulting in interval censored data. Recently, most studies focused on modeling the true disease progression as a discrete time stationary Markov chain, and only a few studies have been carried out regarding non-homogenous multi-state models in the presence of interval-censored data. In this dissertation, several likelihood-based methodologies were proposed to deal with interval censored data in multi-state models. Firstly, a continuous time version of a homogenous Markov multi-state model with backward transitions was proposed to handle uneven follow-up assessments or skipped visits, resulting in the interval censored data. Simulations were used to compare the performance of the proposed model with the traditional discrete time stationary Markov chain under different types of observation schemes. We applied these two methods to the well-known Nun study, a longitudinal study of 672 participants aged ≥ 75 years at baseline and followed longitudinally with up to ten cognitive assessments per participant. Secondly, we constructed a non-homogenous Markov model for this type of panel data. The baseline intensity was assumed to be Weibull distributed to accommodate the non-homogenous property. The proportional hazards method was used to incorporate risk factors into the transition intensities. Simulation studies showed that the Weibull assumption does not affect the accuracy of the parameter estimates for the risk factors. We applied our model to data from the BRAiNS study, a longitudinal cohort of 531 subjects each cognitively intact at baseline. Last, we presented a parametric method of fitting semi-Markov models based on Weibull transition intensities with interval censored cognitive data with death as a competing risk. We relaxed the Markov assumption and took interval censoring into account by integrating out all possible unobserved transitions. The proposed model also allowed for incorporating time-dependent covariates. We provided a goodness-of-fit assessment for the proposed model by the means of prevalence counts. To illustrate the methods, we applied our model to the BRAiNS study.
5

Skapandet av B.O.B. - Balls Over Brains : om konsten att väcka intresse hos spelaren för att fortsätta spela

Bartziokas, Andreas January 2009 (has links)
<p>Detta arbete är skapat av Andreas Bartziokas, som examensarbete för VT 2009. I denna uppsats beskrivs hur spelet B.O.B. har skapats. Vilken litteratur som varit användbar för skapandet av spelet, samt en övergripande beskrivning av själva spelet.</p>
6

Skapandet av B.O.B. - Balls Over Brains : om konsten att väcka intresse hos spelaren för att fortsätta spela

Bartziokas, Andreas January 2009 (has links)
Detta arbete är skapat av Andreas Bartziokas, som examensarbete för VT 2009. I denna uppsats beskrivs hur spelet B.O.B. har skapats. Vilken litteratur som varit användbar för skapandet av spelet, samt en övergripande beskrivning av själva spelet.
7

Estudo anatômico do tronco encefálico do macaco Cebus apella / Anatomical study of the brain stem of the Cebus apella monkey

Marques, Karina do Valle 28 March 2005 (has links)
Os macacos Cebus apella são hábeis com suas mãos e capazes de utilizar ferrementas (paus e pedras) para resolver problemas, podendo ser treinados como assistentes de pessoas quadriplégicas. São escassas ainda as informações em neuroanatomia desses primatas, o que motiva a presente pesquisa, cujo propósito é o de enfocar a morfologia externa e interna do tronco encefálico. Foram estudados 20 espécimes do macaco Cebus apella que já estavam fixados com formol a 10%, pertencentes ao acervo de pesquisa do laboratório de Anatomia da Universidade Federal de Uberlândia. Após isolamento do encéfalo e remoção das meninges procedeu ? se ao estudo da superfície externa em 14 peças. A dissecção por técnica usual preservou características morfológicas da superfície e origem aparente de nervos cranianos, que foram identificados. Em análise macroscópica, o tronco encefálico mostra ? se bem desenvolvido destacando ? se ainda em sua face lateral a origem aparente do nervo trigêmeo e os pedúnculos cerebelares médios, bem evidentes. Na face dorsal, em relação ao IV ventrículo identificam ? se os véus medulares superior e inferior, bem como o sulco mediano e a eminência medial. Os pedúnculos cerebelares superior e inferior também são bem destacados. Na medula oblonga são identificados, entre outros, os relevos correspondentes às olivas e às pirâmides, além da fissura mediana anterior e a região da decussação das pirâmides, Nem sempre são nítidos o sulco bulbo ? pontino e o forame cego. Os fascículos grácil e cuneiforme são bastante desenvolvidos bem como os tubérculos correspondentes. Para os estudos das estruturas internas do tronco encefálico, 6 peças, já fixadas, foram congeladas com nitrogênio líquido e cortadas no criostato entre ?27&ordm; C e ? 30&ordm; C, seguindo ? se a feitura de cortes transversais, em seis níveis (colículos superior e inferior, origem aparente do nervo trigêmeo, porções superior, média e inferior da oliva, e decussação das pirâmides), com espessura de 60 &micro;c, corados segundo o método de Mulligan. As estruturas evidenciáveis são descritas com detalhes comparando ? se os dados obtidos com os da literatura consultada. Os termos anatômicos foram referidos segundo a Terminologia Anatômica Internacional, 1&ordf; edição brasileira ? 2001, Ed. Manole Ltda. / The Cebus apella monkey are able to use their nands and to use tools like woods and stones to solve problems. They can be trained to act as quadriplégicas people?s assistants. The Neuroanatomy information about these primates are little, that?s the reason for this research and its purpose is to accomplish a macroscophial anatomic study of encephalic trunk external and internal surface structure. It was studied Cebus apella monkeu 20 especimens that was already fixed on 10% formaldehyde. These monkeys are from research?s heap of Universidade Federal de Uberlândia. The monkey encephalon were removed using an osteótomo. After removing the meninges, theirs external surface study was started on 14 of them. The dissection using usual technique could preserve the morphological characteristics of the surface and cranial nerve apparent origim, that could be identified too. Under a macroscophical analysis, the encephalic trun looks very elaborated and the trigemini nerve and pedunculus cerebellaris aparent origin, very evident, was stood out in its lateral face. In the dorsal face, in relation to fourth ventricle, the inferior and superior velum medullare could be identified as well as the sulcus medianus and the eminentia medialis. The superior pedunculus cerebellaris, as well as the inferior ones, were very stood out too. On the medulla oblongata were identified, beyond others, the relieves corresponding to the oliva and the decussatio pyramidum region. The sulcus bulbus ? pons and the foramen caecum not always are bright. The fasciculus gracilis, as well as the cuneatus ones, are very elaborated as well as the corresponding tuberculuns.The brain stem internal structure study 6 already fixed pieces were froze with liquid nitrong and cut in criostato, under the temperature between ?27&ordm;C and ? 30&ordm; C. After this, transversal cuts were made on 6 levels (superior and inferior nerve trigemini aparent origin, olivas superior, medium and inferior portion and decussatio pyramidum), with the thickness of 60&micro;c, roddy according to the Mulligan method. The evidentiable structures are described in details comparing data obtained from the consulted literature. The anatomic terms were aforesaid according to Terminologia Anatômica Internacional, 1&ordf; edição brasileira ? 2001, Ed. Manole Ltda.
8

Functional MRI Data Analysis Techniques and Strategies to Map the Olfactory System of a Rat Brain.

Kulkarni, Praveen P 19 January 2006 (has links)
Understanding mysteries of a brain represents one of the great challenges for modern science. Functional magnetic resonance imaging (fMRI) has two features that make it unique amongst other imaging modalities used in behavioral neuroscience. First, it can be entirely non-invasive and second, fMRI has the spatial and temporal resolution to resolve patterns of neuronal activity across the entire brain in less than a minute. fMRI indirectly detects neural activity in different parts of the brain by comparing contrast in MR signal intensity prior to and following stimulation. Areas of the brain with increased synaptic and neuronal activity require increased levels of oxygen to sustain this activity. Enhanced brain activity is accompanied by an increase in metabolism followed by increases in blood flow and blood volume. The enhanced blood flow usually exceeds the metabolic demand exposing the active brain area to high level of oxygenated hemoglobin. Oxygenated hemoglobin increases the MR signal intensity that can be detected in MR scanner. This relatively straight forward scenario is, unfortunately, oversimplified. The fMRI signal change to noise ratio is extremely small. In this work a quantitative analysis strategy to analyze fMRI data was successfully developed, implemented and optimized for the rat brain. Therein, each subject is registered or aligned to a complete volume-segmented rat atlas. The matrices that transformed the subject's anatomy to the atlas space are used to embed each slice within the atlas. All transformed pixel locations of the anatomy images are tagged with the segmented atlas major and minor regions creating a fully segmented representation of each subject. This task required the development of a full 3D surface atlas based upon 2D non-uniformly spaced 2D slices from an existing atlas. A multiple materials marching cube (M3C) algorithm was used to generate these 1277 subvolumes. After this process, they were coalesced into a dozen major zones of the brain (amygdaloid complex, cerebrum, cerebellum, hypothalamus, etc.). Each major brain category was subdivided into approximately 10 sub-major zones. Many scientists are interested in behavior and reactions to pain, pleasure, smell, for example. Consequently, the 3D volume atlas was segmented into functional zones as well as the anatomical regions. A utility (program) called Tree Browser was developed to interactively display and choose different anatomical and/or functional areas. Statistical t-tests are performed to determine activation on each subject within their original coordinate system. Due to the multiple t-test analyses performed, a false-positive detection controlling mechanism was introduced. A statistical composite of five components was created for each group. The individual analyses were summed within groups. The strategy developed in this work is unique as it registers segments and analyzes multiple subjects and presents a composite response of the whole group. This strategy is robust, incredibly fast and statistically powerful. The power of this system was demonstrated by mapping the olfactory system of a rat brain. Synchronized changes in neuronal activity across multiple subjects and brain areas can be viewed as functional neuro-anatomical circuits coordinating the thoughts, memories and emotions for particular behaviors using this fMRI module.
9

Estudo anatômico do tronco encefálico do macaco Cebus apella / Anatomical study of the brain stem of the Cebus apella monkey

Karina do Valle Marques 28 March 2005 (has links)
Os macacos Cebus apella são hábeis com suas mãos e capazes de utilizar ferrementas (paus e pedras) para resolver problemas, podendo ser treinados como assistentes de pessoas quadriplégicas. São escassas ainda as informações em neuroanatomia desses primatas, o que motiva a presente pesquisa, cujo propósito é o de enfocar a morfologia externa e interna do tronco encefálico. Foram estudados 20 espécimes do macaco Cebus apella que já estavam fixados com formol a 10%, pertencentes ao acervo de pesquisa do laboratório de Anatomia da Universidade Federal de Uberlândia. Após isolamento do encéfalo e remoção das meninges procedeu ? se ao estudo da superfície externa em 14 peças. A dissecção por técnica usual preservou características morfológicas da superfície e origem aparente de nervos cranianos, que foram identificados. Em análise macroscópica, o tronco encefálico mostra ? se bem desenvolvido destacando ? se ainda em sua face lateral a origem aparente do nervo trigêmeo e os pedúnculos cerebelares médios, bem evidentes. Na face dorsal, em relação ao IV ventrículo identificam ? se os véus medulares superior e inferior, bem como o sulco mediano e a eminência medial. Os pedúnculos cerebelares superior e inferior também são bem destacados. Na medula oblonga são identificados, entre outros, os relevos correspondentes às olivas e às pirâmides, além da fissura mediana anterior e a região da decussação das pirâmides, Nem sempre são nítidos o sulco bulbo ? pontino e o forame cego. Os fascículos grácil e cuneiforme são bastante desenvolvidos bem como os tubérculos correspondentes. Para os estudos das estruturas internas do tronco encefálico, 6 peças, já fixadas, foram congeladas com nitrogênio líquido e cortadas no criostato entre ?27&ordm; C e ? 30&ordm; C, seguindo ? se a feitura de cortes transversais, em seis níveis (colículos superior e inferior, origem aparente do nervo trigêmeo, porções superior, média e inferior da oliva, e decussação das pirâmides), com espessura de 60 &micro;c, corados segundo o método de Mulligan. As estruturas evidenciáveis são descritas com detalhes comparando ? se os dados obtidos com os da literatura consultada. Os termos anatômicos foram referidos segundo a Terminologia Anatômica Internacional, 1&ordf; edição brasileira ? 2001, Ed. Manole Ltda. / The Cebus apella monkey are able to use their nands and to use tools like woods and stones to solve problems. They can be trained to act as quadriplégicas people?s assistants. The Neuroanatomy information about these primates are little, that?s the reason for this research and its purpose is to accomplish a macroscophial anatomic study of encephalic trunk external and internal surface structure. It was studied Cebus apella monkeu 20 especimens that was already fixed on 10% formaldehyde. These monkeys are from research?s heap of Universidade Federal de Uberlândia. The monkey encephalon were removed using an osteótomo. After removing the meninges, theirs external surface study was started on 14 of them. The dissection using usual technique could preserve the morphological characteristics of the surface and cranial nerve apparent origim, that could be identified too. Under a macroscophical analysis, the encephalic trun looks very elaborated and the trigemini nerve and pedunculus cerebellaris aparent origin, very evident, was stood out in its lateral face. In the dorsal face, in relation to fourth ventricle, the inferior and superior velum medullare could be identified as well as the sulcus medianus and the eminentia medialis. The superior pedunculus cerebellaris, as well as the inferior ones, were very stood out too. On the medulla oblongata were identified, beyond others, the relieves corresponding to the oliva and the decussatio pyramidum region. The sulcus bulbus ? pons and the foramen caecum not always are bright. The fasciculus gracilis, as well as the cuneatus ones, are very elaborated as well as the corresponding tuberculuns.The brain stem internal structure study 6 already fixed pieces were froze with liquid nitrong and cut in criostato, under the temperature between ?27&ordm;C and ? 30&ordm; C. After this, transversal cuts were made on 6 levels (superior and inferior nerve trigemini aparent origin, olivas superior, medium and inferior portion and decussatio pyramidum), with the thickness of 60&micro;c, roddy according to the Mulligan method. The evidentiable structures are described in details comparing data obtained from the consulted literature. The anatomic terms were aforesaid according to Terminologia Anatômica Internacional, 1&ordf; edição brasileira ? 2001, Ed. Manole Ltda.
10

A method for automated landmark constellation detection using evolutionary principal components and statistical shape models

Lu, Wei 01 December 2010 (has links)
Medical imaging technologies such as MRI, CT, PET, etc. enable the use of higher resolution 3D digital image data for research and clinical treatment. The new technologies provide improved spatial resolution at the cost of increased data processing time. Manual identification of anatomical landmarks is still a common practice in many neuroimaging and other medical imaging applications but it is labor-intensive, subjective, and suffers from intra-/inter- rater inconsistency. This work explored one way of estimating a landmark constellation automatically, consistently, and efficiently. The proposed method demonstrated a successful application on how to effectively utilize image processing in tackling clinical challenges. It is shown that the cooperation of spatial localization using linear model prediction with evolutionary principal components and local search estimation using statistical shape models is capable of effectively extracting important landmark detection information from both morphometric relationships of landmarks and consistent intensity distribution of images. It is accurate (compared to 1.6 mm root mean squared errors of manual labeling of brain landmarks), consistent, reliable in predicting many salient midbrain point landmarks such as ac, pc, MPJ, etc. in a longitudinal, multisubject environment, and throughout large datasets with different modalities and image information such as orientation, spacing, and origin. The framework of linear model estimation method using evolutionary principal components and the idea of local search using statistical shape models are generalized to the detection task for arbitrary number of landmarks in other organs, creatures, or even any other physical objects in the world as long as the landmarks present intensity consistency and satisfy regularity in spatial organization.

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