516 research outputs found
JCB918029 Supplemental Material - Supplemental material for Simulating the effect of cerebral blood flow changes on regional quantification of [<sup>18</sup>F]flutemetamol and [<sup>18</sup>F]florbetaben studies
No full textSupplemental material, JCB918029 Supplemental Material for Simulating the effect of cerebral blood flow changes on regional quantification of [18F]flutemetamol and [18F]florbetaben studies by Fiona Heeman, Maqsood Yaqub, Isadora Lopes Alves, Kerstin Heurling, Santiago Bullich, Juan D Gispert, Ronald Boellaard, Adriaan A Lammertsma and on behalf of the AMYPAD Consortium in Journal of Cerebral Blood Flow & Metabolism</p
Adília Lopes: writing as life
No full textA proposed reading of the latest books by contemporary Portuguese poet Adília Lopes, who passed away in December 2024. A collection of works featuring photographs of the author\u27s home and personal life as paratexts, creating a play of fiction/truth reflected in the now accentuated shift between the two names: Maria José/Adília Lopes. Childhood as writing and time as the guiding thread of a final production that asserts itself as a space of play (language and its games) and pleasure (the freedom to be and live in writing). The idea of the photo album/memory album as a fictionalized construction (collages) of life in literature. The creation of scrapbooks. The connection between the writing process of these books and Roland Barthes\u27s thought composing his own patchwork in Barthes (1977)Proposta de leitura dos últimos livros da poeta portuguesa contemporânea, Adília Lopes, falecida em dezembro de 2024. Articulação de obras que apresentam como paratextos fotografias pessoais e da casa da Autora, instalando um jogo de ficção/verdade que se reflete no deslocamento agora acentuado entre as nomeações Maria José/Adília Lopes. A infância como escrita e o tempo como fio condutor de uma produção final que se afirma como espaço de brinquedo (a língua e seus jogos) e de prazer (a liberdade de ser e de viver na escrita). A ideia de álbum de fotos / álbum de memórias como construção ficcionalizada (colagens) da vida no literário. A elaboração de scrapbooks. A aproximação entre o processo de escrita desses livros e o pensamento de Roland Barthes compondo seu próprio patch-work em Barthes (1977)
Com-posições na educação infantil: a hipótese de uma dança-invenção
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação, Programa de Pós-Graduação em Educação, Florianópolis, 2013.Esta dissertação objetiva pensar as possibilidades da dança não formal para a Educação da Infância, principalmente - mas não exclusivamente- para o trabalho em Instituições de Educação Infantil que lidam com crianças de 0 a 6 anos. Para tanto, parte de uma breve arqueologia da dança, suas variações e esforços conceituais, recolhendo traços importantes de cada um deles, no sentido da elaboração de um conceito - "A Dança-Invenção" - que responda às demandas do cotidiano educativo. A pesquisa naturalmente desloca-se para as possibilidades subjetivas do trabalho com dança inventiva, de maneira a integrar movimento e imaginário. Riassunto : Questa tesi ha l'obiettivo di riflettere sui possibili usi della danza non formale nell'Educazione dell'Infanzia principalmente - ma non esclusivamente - per leattività in Istituzioni di Educazione Infantile che si occupano di bambini da 0 a 6 anni. Per questo motivo, partendo da una breve archeologia della danza, dellesue varianti ed impegni concettuali, verranno raccolti importanti elementi dientrambi, allo scopo di elaborare un concetto - "La Danza-Invenzione" - che risponda alle richieste della quotidianità educativa. La ricerca, naturalmente, siestende alle possibilità soggettive del lavoro con la danza inventiva, così da integrare movimento ed immaginario
A obra para flauta e guitarra de Fernando Lopes-Graça
No full textMestrado em MúsicaEste estudo incide sobre o repertório para flauta e guitarra do compositor
Fernando Lopes-Graça, e justifica a sua interpretação à luz do percurso do
autor enquanto compositor, intérprete, crítico e ser humano.
Começámos por delinear um perfil estético do compositor, cuja identidade se
caracteriza por um comportamento interventivo como resposta às políticas
nacionais da época, vincada pelo recurso às fontes rústicas como meio de
expressão musical. Seguidamente, delineámos as causas que estiveram na
génese das obras para flauta e guitarra, compreendendo-as a partir da relação
do compositor com o seu intérprete. Finalmente, analisámos o conteúdo
musical e poético presente nas fontes das Melodias Rústicas Portuguesas –
IVº caderno, estabelecendo um quadro sonoro e estético para as regiões de
origem de cada uma das suas melodias, de maneira a definirmos novas
opções interpretativas.
Fundamentar um percurso interpretativo, despertar futuras abordagens e
investigações que possam contribuir para o aprofundamento da vida e obra de
Fernando Lopes-Graça, assim como, dar a conhecer o repertório para flauta e
guitarra do compositor, são os principais objectivos deste estudo.
ABSTRACT: This study focuses on the repertoire for flute and guitar of the composer
Fernando Lopes-Graça and it justifies his interpretation taking into account the
author as a composer, an interpreter, a critic and a human being.
We have begun by outlining the composer’s aesthetic profile, whose identity is
characterised by interventionist behaviour in response to the national policies of
the time, and influenced by the use of rustic sources as a means of musical
expression. Then, we have outlined the causes which led to the genesis of
works for flute and guitar, understanding them by taking into consideration the
composer's relationship with his interpreter. Finally, we have examined the
musical and poetic contents which are part of the sources of Portuguese Rustic
Melodies - IVth book, establishing a resonant and aesthetic framework for the
regions of origin of each of these melodies, in order to define new interpretative
options.
Supporting an interpretative path, raising future approaches and investigations
in order to deepen the knowledge of the life and work of Fernando Lopes-
Graça, as well as raising awareness of the repertoire for flute and guitar of this
composer, are the main objectives of this study
Identity, gauchismo and the the seamy side of history in Contos gauchescos, by Simões Lopes Neto
No full textPartindo dos estudos de Benedict Anderson e de Stuart Hall, entre outros, este artigo busca analisar alguns aspectos da construção identitária do gaúcho, conforme foi consolidada ao longo do tempo pelo imaginário e pela literatura. Para tanto, relembra-se alguns momentos e obras em que o homem dos pampas ganha destaque para, em seguida, examinar os Contos Gauchescos, de João Simões Lopes Neto, verificando especialmente o modo como o autor constrói ficcionalmente o gaúcho, filiando-se à tradição regionalista e, ao mesmo tempo, rompendo com esta.Starting from the studies of Benedict Anderson and Stuart Hall, among others, this article seeks to analyze some aspects of identity construction of the gaucho, as was consolidated throughout the time by imaginary and literature. For that, it recalls some moments and works in which the man of the pampas is highlighted and, then, examines Contos Gauchescos, by João Simões Lopes Neto, checking especially the way as the author builds fictionally the gaucho, joining with the regionalist tradition and, at the same time, breaking with this
Castro Alves : o modo como sua obra tem sido abordada em livros didáticos do ensino médio em comparação com as opiniões de grandes críticos da literatura brasileira
No full textTrabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Instituto de Letras, Departamento de Teoria Literária e Literatura, 2018.Este artigo analisa o modo como a obra de Castro Alves tem sido abordada em
livros didáticos do ensino médio em comparação com as opiniões dispersadas por
grandes críticos da literatura brasileira a respeito do autor, conhecido por ser
extremamente ligado às inspirações revolucionárias e liberais do século XIX. Após o
levantamento da fortuna crítica quanto às diferentes opiniões de críticos da literatura
brasileira, foram destacadas as mudanças de abordagem dos livros, bem como as
diferenças nos métodos e conteúdos didáticos. Por fim, elucidou-se quais são as
abordagens comuns às histórias da literatura e aos livros didáticos, quanto à obra de
Castro Alves, e qual segmento crítico (dos autores supracitados) os livros didáticos
mais adotam. Além disso, foi abordada também a questão feminina, que, por sua
vez, foi bastante explorada nos livros didáticos.This article analyzes how Castro Alves' literary work has been approached in high
school textbooks in comparison to the opinions dispersed by great critics of Brazilian
literature about the author, known to be extremely connected to the revolutionary
and liberal inspirations of the 19th century. After the critical fortune was raised
regarding the different opinions of critics to the Brazilian literature, the different
approaches of the books were highlighted, as well as the differences in the didactic
methods and contents were highlighted. Finally, it was elucidated which are the
common approaches to the stories of the literature and to the didactic books,
regarding to literary work of Castro Alves, and which critical segment (of the
aforementioned authors) the high schools textbooks more adopt. In addition, the
feminine question was also addressed, which, in turn, was extensively explored in
textbooks
Quantitative amyloid PET imaging in Alzheimer’s disease:Walking the line between accuracy and simplicity
No full textPositron emission tomography (PET) allows for in vivo visualisation and quantification of amyloid-β (Aβ) plaques, which are known to play a major role in the development of Alzheimer’s disease (AD). However, it remains unclear whether these plaques have a causal relationship with AD dementia. Quantitatively tracking of Aβ plaques using PET may 1) enhance our understanding of AD, 2) improve our ability to predict who will develop AD dementia and 3) improve participant selection in secondary prevention trials. Typically, quantification requires a dynamic scan and measurement of the available PET tracer in plasma. As these are time consuming and complex procedures, widespread implementation in clinical or research practise is not feasible and warrants simplified approaches. The overall aim of this thesis was to evaluate to what extent approaches for quantification of Aβ pathology using PET can be simplified, within the context of different applications. In short, the main findings of this thesis were that, in case of the [18F]flutemetamol, [18F]florbetaben and [11C]PiB amyloid tracers, the semi-quantitative standardized uptake value ratio (SUVR), calculated from a static PET scan, showed a bias that was proportional to underlying Aβ pathology compared with the quantitative distribution volume ratio (DVR). The bias was smallest in participants (or regions) with very low levels of Aβ pathology and the effect of cerebral blood flow changes on bias in SUVR appeared to be minimal in cognitively unimpaired individuals. The proportional bias in SUVR suggests that for highly accurate quantification of Aβ pathology, such as when measuring small changes in longitudinal studies, dynamic or validated dual-time window scanning protocols may be required. More specifically, the present work showed that dual-time window protocols can substitute dynamic protocols with only limited loss of accuracy, while increasing patient comfort and throughput. Clearly, highly accurate and robust quantification can only be achieved if these scanning protocols are used in combination with a validated pharmacokinetic model and reference tissue, if applicable. Another advantage of dynamic and dual-time window scanning protocols is that a measure of relative tracer delivery (R1) can be extracted. In terms of its methodological characteristics, it was demonstrated that R1 is a stable parameter and, it has the potential to serve as an additional biomarker for measuring disease progression in AD. Finally, considering that Aβ plaque accumulation starts focally, research aiming to measure small changes in Aβ pathology over time should focus on regional instead of global measures of Aβ pathology. This strategy has the potential to improve participant selection in clinical trials and predict cognitive decline. In addition, regional quantification of amyloid burden and the use of dynamic scanning protocols can reduce the required sample sizes in primary and secondary AD prevention trials
Challenges and opportunities in quantitative brain PET imaging
No full textEen van de voornaamste voordelen voor de beeldvorming van Positron Emissie Tomografie (PET) is het verkrijgen van kwantitatieve informatie omtrent fysiologische processen. Helaas vereisen de wiskundige modellen voor het kwantificeren over het algemeen lange acquisitieprotocollen en potentiele invasieve procedures, welke zorgen voor uitdagingen in termen van patiënt comfort en de bezetting van de gezondheidszorg. Als gevolg, de kwantitatieve kwaliteiten van PET komen niet terecht in de klinische toepassing en veel preklinische studies (kleine dierlijke studies) onderzoeken de potentie van kwantificatiemodellen niet volledig. In deze context onderzoekt deze thesis een aantal kansen om 1) het gat te overbruggen tussen het kwantitatieve potentieel en de noodzaak van simpele methodes voor klinische toepassing en 2) het optimaliseren van kwantitatieve methodologieën voor de preklinische omgeving. Ten eerste zijn er twee nieuwe gesimplificeerde methodes ontwikkeld en gevalideerd. Deze methodes pasten wiskundige benaderingen toe om modellen vast te stellen en waren succesvol in het significant reduceren van PET-scan tijd zonder nadelig te zijn voor de kwantitatieve accuraatheid. Als consequentie is het mogelijk volledige kwantitatieve informatie te verkrijgen door middel van korte, simpele, patiëntvriendelijke scans. Vervolgens richtte het onderzoek zich op het optimaliseren van kwantitatieve methodologie voor PET-beeldvorming van het rattenbrein. Hier werd een gevestigde tracer uit menselijk onderzoek geëvalueerd op specifieke toepassing in de preklinische omgeving en optimale kwantitatieve methodes vastgesteld. De bevindingen van dit werk lieten zien dat het niet mogelijk is de methodologie van mensen direct toe te passen op onderzoek bij ratten. Het markeerde het belang van model validatie, ook in het geval van radiotracers welke vastgesteld zijn voor een ander soort.One of the main advantages of Positron Emission Tomography (PET) imaging is the potential to obtain quantitative information about physiological processes. Unfortunately, the mathematical models that allow for quantitation generally require long image acquisition protocols and potentially invasive procedures, which poses challenges in terms of patient comfort and healthcare resource utilization. As a consequence, the quantitative character of PET does not find space in the clinical practice, and many preclinical studies (small animal imaging) also do not explore quantification methods to the fullest. In this context, this thesis explored a number of opportunities to 1) bridge the gap between quantitative potential and the necessity of simple methods for clinical practice and to 2) optimize quantitative methodologies for the preclinical setting. First, two novel simplified methods were developed and validated. The methods applied mathematical approximations to established models and were successful in significantly reducing PET scan time without compromising quantitative accuracy. As a consequence, full quantitative information might be obtained from simple, short, patient-friendly scans. Next, the thesis focused on optimizing quantitative methodology for PET imaging of the rat brain. There, a well-established radiotracer in human studies was assessed for its specific use in the preclinical setting, and optimal quantitative methods were determined. The findings of this work showed it is not possible to directly translate methodology from human to rat studies, and highlighted the importance of model validation, also in the case of radiotracers which have been established in a different species
Supplementary material for "Multi-tracer model for staging cortical amyloid deposition using PET imaging"
No full textObjective: To develop and evaluate a model for staging cortical amyloid deposition using PET with high generalizability.
Methods: 3027 subjects (1763 Cognitively Unimpaired (CU), 658 Impaired, 467 Alzheimer's disease (AD) dementia, 111 non-AD dementia, and 28 with missing diagnosis) from six cohorts (EMIF-AD, ALFA, ABIDE, ADC, OASIS-3, ADNI) who underwent amyloid PET were retrospectively included; 1049 subjects had follow-up scans. Applying dataset-specific cut-offs to global Standard Uptake Value ratio (SUVr) values from 27 regions, single-tracer and pooled multi-tracer regional rankings were constructed from the frequency of abnormality across 400 CU subjects (100 per tracer). The pooled multi-tracer ranking was used to create a staging model consisting of four clusters of regions as it displayed a high and consistent correlation with each single-tracer ranking. Relationships between amyloid stage, clinical variables and longitudinal cognitive decline were investigated.
Results: SUVr abnormality was most frequently observed in cingulate, followed by orbitofrontal, precuneal, and insular cortices, then the associative, temporal and occipital regions. Abnormal amyloid levels based on binary global SUVr classification were observed in 1.0%, 5.5%, 17.9%, 90.0%, and 100.0% of stage 0-4 subjects, respectively. Baseline stage predicted decline in MMSE (ADNI: N=867, F=67.37, p<0.001; OASIS: (N=475, F=9.12, p<0.001) and faster progression towards an MMSE≤25 (ADNI: N=787, HRstage1=2.00, HRstage2=3.53, HRstage3=4.55, HRstage4=9.91, p<0.001; OASIS: N=469, HRstage4=4.80, p<0.001).
Conclusion: The pooled multi-tracer staging model successfully classified the level of amyloid burden in >3000 subjects across cohorts and radiotracers, and detects pre-global amyloid burden and distinct risk profiles of cognitive decline within globally amyloid-positive subjects
Challenges and opportunities in quantitative brain PET imaging
No full textEen van de voornaamste voordelen voor de beeldvorming van Positron Emissie Tomografie (PET) is het verkrijgen van kwantitatieve informatie omtrent fysiologische processen. Helaas vereisen de wiskundige modellen voor het kwantificeren over het algemeen lange acquisitieprotocollen en potentiele invasieve procedures, welke zorgen voor uitdagingen in termen van patiënt comfort en de bezetting van de gezondheidszorg. Als gevolg, de kwantitatieve kwaliteiten van PET komen niet terecht in de klinische toepassing en veel preklinische studies (kleine dierlijke studies) onderzoeken de potentie van kwantificatiemodellen niet volledig. In deze context onderzoekt deze thesis een aantal kansen om 1) het gat te overbruggen tussen het kwantitatieve potentieel en de noodzaak van simpele methodes voor klinische toepassing en 2) het optimaliseren van kwantitatieve methodologieën voor de preklinische omgeving. Ten eerste zijn er twee nieuwe gesimplificeerde methodes ontwikkeld en gevalideerd. Deze methodes pasten wiskundige benaderingen toe om modellen vast te stellen en waren succesvol in het significant reduceren van PET-scan tijd zonder nadelig te zijn voor de kwantitatieve accuraatheid. Als consequentie is het mogelijk volledige kwantitatieve informatie te verkrijgen door middel van korte, simpele, patiëntvriendelijke scans. Vervolgens richtte het onderzoek zich op het optimaliseren van kwantitatieve methodologie voor PET-beeldvorming van het rattenbrein. Hier werd een gevestigde tracer uit menselijk onderzoek geëvalueerd op specifieke toepassing in de preklinische omgeving en optimale kwantitatieve methodes vastgesteld. De bevindingen van dit werk lieten zien dat het niet mogelijk is de methodologie van mensen direct toe te passen op onderzoek bij ratten. Het markeerde het belang van model validatie, ook in het geval van radiotracers welke vastgesteld zijn voor een ander soort
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