7 research outputs found

    Les habilitats de comunicació social primerenca i la seua relació amb la competència lingüística i amb la presència de marcadors de risc d’autisme: estudi longitudinal dels 8 als 18 mesos d’edat

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    Des del naixement, els bebès mostren una atracció natural per les cares humanes (Bedford et al., 2012; Droucker, Curtin, & Vouloumanos, 2013). Així mateix, des dels primers mesos de vida, manifesten un fort interès per mirar cap a la direcció que indica la mirada de l'adult (Farroni, Massaccesi, Menon, & Johnson, 2004). Al voltant dels 6-8 mesos, aprenen a alinear deliberadament la seua pròpia mirada amb la mirada de l’adult (Beuker, Rommelse, Donders, & Buitelaar, 2013). Més tard, passen de seguir la direcció de la mirada de l’adult als 6 mesos a comprendre la intencionalitat d’aquesta mirada al voltant dels 12 mesos (Tomasello, Carpenter, Call, & Behne, 2005). Amb la comprensió del significat d’aquesta mirada apareix l’atenció conjunta. L’atenció conjunta és l’habilitat de coordinar l’atenció per adoptar un punt de referència comú amb una altra persona. Aquest punt de referència comú sol ser un objecte o un esdeveniment d’interès (Mundy & Newell, 2007; Salo, Rowe, & Reeb‐Sutherland, 2018; Scaife & Bruner, 1975). És un clar indicador de comprensió de les representacions dels altres (Brooks & Meltzoff, 2005), i té un paper important en l’aparició del pensament simbòlic i en el desenvolupament del llenguatge (Jones et al., 2009; Salo et al., 2018). Aquesta habilitat té, principalment, una funcionalitat declarativa, quan s'usa per a compartir motivacions i interessos amb els altres, però també pot tenir un ús instrumental-imperatiu, quan s'empra per a aconseguir un objecte o un objectiu (Mundy et al., 2007; Salo et al., 2018). Tradicionalment, s’ha utilitzat el terme d’atenció conjunta per a referir-se a l’ús declaratiu d’aquesta conducta comunicativa, i se sol utilitzar el terme de conducta de demanda per a referir-se al seu ús instrumental-imperatiu (Mundy et al., 2003; Seibert, Hogan, & Mundy, 1982). Aquestes dues dimensions de l’atenció compartida formen part del que anomenem “habilitats de la comunicació social primerenca”. A més a més, hem d’incloure també una tercera dimensió: la interacció social. La interacció social es refereix a aquelles conductes en què l’infant i el cuidador participen en activitats lúdiques, d’afectivitat positiva i reciprocitat (Harrist & Waugh, 2002). Pot comportar l’ús d’objectes, però la referència a l’objecte no és una característica principal. Alguns exemples són fer-se pessigolles o jugar a passar-se una pilota per torns (Mundy et al., 2003). Les conductes d’atenció conjunta i de conducta de demanda són de naturalesa triàdica, vist que típicament intervenen dos interlocutors i un objecte. D’altra banda, la conducta d’interacció social té un caràcter diàdic, perquè sol donar-se entre dues persones i sense la necessitat que hi haja també un tercer element. Així, parlaríem de tres dimensions en la comunicació social primerenca: (1) l’atenció conjunta, (2) la conducta de demanda i (3) la interacció social. Els dèficits en aquestes habilitats, especialment les dificultats en atenció conjunta, són un dels marcadors més clars de signes primerencs del trastorn de l’espectre autista (TEA) (Curcio, 1978; Ibáñez, Grantz, & Messinger, 2013; Macari et al., 2012; Mundy et al., 2007; Mundy, 2016; Schertz, Odom, Baggett, & Sideris, 2018; Thorup et al., 2018). L'objectiu del present treball ha estat avaluar les habilitats de la comunicació social primerenca en una mostra de xiquets nascuts a la província de València en tres moments evolutius (8, 12 i 18 mesos), per tal d’explorar si aquestes habilitats en els moments evolutius més primerencs es relacionen amb les habilitats del llenguatge en els posteriors moments evolutius, i amb la presència de signes primerencs de TEA als 12 mesos i als 18 mesos d’edat. Es tracta d’un estudi de cohort longitudinal prospectiu amb tres moments d’avaluació: 8 mesos, 12 mesos i 18 mesos. La mostra ha estat formada per 55 bebès nascuts a la província de València i les seues famílies: 24 xiquets (43.6%) i 31 xiquetes (56.4%). Als 8 mesos s’avaluaren 52 xiquets, als 12 mesos s’avaluaren 45 xiquets i als 18 mesos s’avaluaren 30 xiquets. La majoria d’aquests participants en cada moment són el mateix xiquet que ha estat avaluat en els tres moments. En alguns casos, són xiquets que han estat avaluats als 8 i als 12 mesos, mentre que en altres casos ho han estat als 8 i als 18 mesos. Una minoria de xiquets participants han estat avaluats només als 8 mesos. El reclutament de la mostra es realitzà amb la col·laboració de diversos professionals vinculats a Centres de Salut i Hospitals de la ciutat de València. L’instrument que s’ha emprat per avaluar les habilitats de comunicació social primerenca és l’Early Social-Communication Scales (ESCS) (Mundy et al., 2003). Les variables avaluades amb aquest instrument han estat: l’inici d’atenció conjunta de baix nivell (IJAL), l’inici d’atenció conjunta d’alt nivell (IJAH), la resposta d’atenció conjunta proximal (RJAP), la resposta d’atenció conjunta distal (RJAD), l’inici de conducta de demanda de baix nivell (IBRL), l’inici de conducta de demanda d’alt nivell (IBRH), la resposta de conducta de demanda total (RBRT), l’inici d’interacció social (ISI), i la resposta d’interacció social total (RSIT). Les variables de baix nivell fan referència a les conductes comunicatives de contacte ocular i d’alternança de mirada, mentre que les variables d’alt nivell fan referència a conductes comunicatives de tipus gestuals (assenyalar, donar o mostrar). Quan una variable és d’inici, significa que és el xiquet qui inicia l’episodi. Quan una variable és de resposta, significa que el xiquet respon a una invitació que fa l’adult. L’etiqueta de proximal significa que l’objecte de referència està a una distància a l’abast del xiquet (per exemple, unes imatges a un llibre). L’etiqueta de distal significa que l’objecte de referència està relativament lluny (per exemple, un pòster en una paret). La competència lingüística s’ha avaluat amb els Inventarios de Desarrollo Comunicativo MacArthur (MCDI) (Jackson-Maldonado et al., 2003), adaptació espanyola de López Ornat et al. (2005). Les variables de competència lingüística que s’han avaluat als 12 mesos són: vocalitzacions (VOC12), comprensió de paraules (WC12), producció de paraules (WP12), i gestos i accions (GA12). Les variables de competència lingüística que s’han avaluat als 18 mesos són: vocalitzacions (VOC18), producció de paraules (WP18), acabament de paraules (WEND18), i complexitat morfosintàctica (MSYC18). Els primers marcadors de simptomatologia TEA s’han avaluat emprant el First Year Inventory (FYI) (Baranek, Watson, Crais, & Reznic, 2003) als 12 mesos, i el Cuestionario de Autismo en la Infancia-Modificado (M-CHAT) (Robins, Fein, Barton, & Green, 2001) als 18 mesos. Als 12 mesos, la presència de signes de TEA ve marcada per la puntuació a l’instrument FYI. A major puntuació, major presència de simptomatologia primerenca. Als 18 mesos, el risc de TEA ve marcat per la presència/absència de marcadors, que s’obtè a partir de l’aplicació de l’instrument M-CHAT (Robins et al., 2001). Per a l’anàlisi de dades s’ha emprant el programa d’anàlisi estadística SPSS, versió 24.0 (Cor, 2016). S’han realitzat anàlisis descriptives, així com anàlisis correlacionals, MANOVA, regressions lineals múltiples i regressions logístiques. Els resultats mostraren correlacions estadísticament significatives entre algunes de les mesures de comunicació social primerenca en cada moment: als 8, als 12 i als 18 mesos. Les correlacions significatives més destacades foren les següents. IJAL i IJAH mostraren una correlació estadísticament significativa: correlacionaren positivament als 8 mesos i negativament als 12 mesos. IJAL i IBRL correlacionaren significativament als 8 mesos, mentre que les seues anàlogues d’alt nivell (IJAH i IBRH) correlacionaren significativament als 12 mesos. IJAL i RJAP correlacionaren significativament als 8 i als 18 mesos. RJAP i RJAD correlacionaren significativament als 8 i als 12 mesos d'edat. Finalment, ISI i RSIT correlacionaren significativament als 8 mesos. Quant a l'evolució de les variables de la comunicació social primerenca, els resultats indicaren que aquestes variables tenen moments d’emergència i d’evolució distints. IJAL i RJAP són conductes que sorgeixen de forma primerenca. És per això que el seu patró de creixement va ser pla, amb puntuacions mitjanes que es mantingueren altes al llarg dels tres moments. Les diferències entre els moments no van ser significatives per a IJAL (8-12 mesos, 12-18 mesos i 8-18 mesos). Pel que fa a RJAP, només les diferències entre els 12 i els 18 mesos van ser significatives. IBRL presentava un ascens dels 8 als 12 mesos d’edat i una lleugera disminució dels 12 als 18 mesos. Les diferències entre els moments van ser significatives en tots els casos per a IBRL (8-12 mesos, 12-18 mesos i 8-18 mesos). IJAH, RJAD, IBRH i RBRT van presentar un patró generalment creixent, amb una puntuació mitjana zero als 8 mesos i un ascens dels 8 als 12 mesos i dels 12 als 18 mesos. Les diferències entre els moments van ser significatives en tots els casos per a aquestes variables (8-12 mesos, 12-18 mesos i 8-18 mesos). ISI i RSIT mostraren un punt de partida baix als 8 mesos, un augment dels 8 als 12 mesos i un patró pla dels 12 als 18 mesos. Les diferències van ser significatives entre els 8 i els 12 mesos i entre els 8 i els 18 mesos per a les variables ISI i RSIT. Pel que fa a la relació entre la comunicació social primerenca i els primers signes de TEA, cap mesura dels 8 mesos fou significativa a l’hora de predir la simptomatologia precoç de TEA als 12 mesos. No obstant això, els primers signes de TEA als 18 mesos pogueren predir-se amb les mesures d’IJA i d’ISI als 8 mesos, i amb les mesures de RJA als 12 mesos. Per últim, els resultats van revelar que les mesures de RJAD als 8 mesos podien predir significativament la comprensió de paraules als 12 mesos, mentre que les mesures de RJAD als 12 mesos podien predir significativament la conducta de vocalització als 18 mesos. En síntesi, sembla que les dificultats d’atenció conjunta als 8 i als 12 mesos són un bon indicador de la presència de primers signes de TEA als 18 mesos. Als 8 mesos, les conductes que més informen sobre aquesta primera simptomatologia són les conductes d’inici d’atenció conjunta, mentre que als 12 mesos són les conductes de resposta d’atenció conjunta. Quant a la competència lingüística, la resposta d’atenció conjunta distal és una conducta comunicativa pre-verbal que es relaciona significativament amb la competència lingüística posterior: amb el volum de vocabulari als 12 mesos i amb la conducta de vocalització als 18 mesos. Aquesta és una investigació que pot contribuir a una millor comprensió del paper de la comunicació social primerenca en el desenvolupament del llenguatge i en la detecció primerenca del TEA. Pot ser una aportació per a futures investigacions més centrades en la detecció i la intervenció precoç. La intervenció primerenca és d’especial interès perquè, fins i tot sense confirmació del diagnòstic, permet el treball de les habilitats socials amb xiquets en risc (Dawson et al., 2010; Johnson, 2008; Kasari, Gulsrud, Freeman, Paparella, & Hellemann, 2012; Kasari, Gulsrud, Wong, Kwon, & Locke, 2010; Reichow & Wolery, 2009; Rogers & Dawson, 2010; Twyman, Maxim, Leet, & Ultman, 2009; Zwaigenbaum, Bryson, & Garon, 2013). A més a més, es produeix durant una etapa del desenvolupament infantil on el cervell gaudeix de major plasticitat, afavorint la generació de canvis permanents en la seua fisiologia (Dawson, 2008; Zwaigenbaum et al., 2013).Babies show a natural attraction for human faces since birth (Bedford et al., 2012; Droucker et al., 2013). Likewise, from the first months of life, they show a strong interest in looking at the direction that the adult’s gaze indicates (Farroni et al., 2004). At about 6-8 months old, they learn to deliberately align their own gaze with the adult’s gaze (Beuker et al., 2013). Then, children go from following the direction of the adult's gaze at 6 months old to understanding the intention of this gaze around 12 months of age (Tomasello et al., 2005). With the understanding of the meaning of this gaze, joint attention emerges Joint attention is the ability to coordinate the attention to adopt a common point of reference with another person. This common point of reference is usually an object or an event of interest (Mundy & Newell, 2007; Salo et al., 2018; Scaife & Bruner, 1975). It is a clear indicator of the comprehension of others’ representations (Brooks & Meltzoff, 2005), and it plays an important role in the emergence of symbolic thinking and language (Jones et al., 2009; Salo et al., 2018). Joint attention has mainly a declaratory functionality, when used to share motivations and interests with others. But it can also have an instrumental-imperative use, when used to achieve an object or an objective (Mundy et al., 2007; Salo et al., 2018). Traditionally, the term joint attention has been used to refer to the declarative use of this communicative behaviour, whereas the term behavioural request is often used to refer to its instrumental-imperative use (Mundy et al., 2003; Seibert et al., 1982). These two dimensions of shared attention are part of what we call "early social communication abilities". In addition to that, we must also include a third dimension: social interaction. Social interaction refers to those behaviours in which the child and the caregiver participate in recreational, of positive affectivity and reciprocity activities (Harrist & Waugh, 2002). It may involve the use of an object, but the reference to the object is not the main feature. Some examples of social interaction are tickling or turn-taking games (Mundy et al., 2003). Joint attention and behavioural request are of a triadic nature, given that typically two interlocutors and an object are involved. On the other hand, social interaction has a dyadic character, because it usually occurs between two people without the need to involve a third element. Thus, we would talk about three dimensions in early social communication: (1) joint attention, (2) behavioural request, and (3) social interaction. Deficits in these abilities, especially difficulties in joint attention, are one of the strongest markers of early signs of autism spectrum disorder (ASD) (Curcio, 1978; Ibáñez et al., 2013; Macari et al., 2012; Mundy et al., 2007; Mundy, 2016; Schertz et al., 2018; Thorup et al., 2018). The objective of this study was to evaluate early social communication in a sample of children born in the province of València, in three evolutionary moments (8, 12 and 18 months). These evaluations were conducted to explore if these early abilities are related to subsequent language skills, and with the presence of ASD early markers at 12 and 18 months of age. This is a prospective longitudinal cohort study with three evaluation moments: 8 months, 12 months and 18 months. The sample was formed of 55 babies born in the province of València and their families: 24 boys (43.6%) and 31 girls (56.4%). At 8 months, 52 children were assessed. At 12 months, 45 children were assessed. At 18 months, 30 children were assessed. Most of these participants at each moment are the same child who was evaluated in all three moments. In some cases, children were evaluated at 8 and 12 months old. In other cases, they were assessed at 8 and 18 months old. A minority of participating children were evaluated only at 8 months old. The recruitment of the sample was carried out with the collaboration of several professionals linked to different Health Centres and Hospitals of the city of València. The instrument used to evaluate early social communication skills was the Early Social-Communication Scales (ESCS) (Mundy et al., 2003). The variables evaluated with this instrument were: lower-level of initiating joint attention (IJAL), higher-level of initiating joint attention (IJAH), responding to proximal joint attention (RJAP), responding to distal joint attention (RJAD), lower-level of initiating behavioural request (IBRL), higher-level of initiating behavioural request (IBRH), responding to behavioural request - total (RBRT), initiating social interaction (ISI), and responding to social interaction - total (RSIT). Lower-level variables refer to communicative behaviours of eye contact and gaze alternation. Higher-level variables refer to gestural communicative behaviours, such as pointing, giving, and showing. When a variable is an initiating variable, that means that it is the child who starts the episode. When a variable is a response variable, that means that the child is responding to an invitation made by the adult. When a variable is proximal, that means that the reference object is at a distance within reach of the child (for example, images in a book). When a variable is distal, that means that the reference object is relatively far (for example, a poster on a wall). Linguistic competence was evaluated with the MacArthur Communicative Development Inventories (MCDI) (Jackson-Maldonado et al., 2003), Spanish adaptation of López Ornat et al. (2005). The linguistic competence variables evaluated at 12 months were: vocalizations (VOC12), word comprehension (WC12), word production (WP12), and gestures and actions (GA12). The linguistic competence variables evaluated at 18 months were: vocalizations (VOC18), word production (WP18), word ending (WEND18), and morphosyntactic complexity (MSYC18). Early markers of ASD symptomatology were evaluated using the First Year Inventory (FYI) (Baranek et al., 2003) at 12 months old, and the Cuestionario de Autismo en la Infancia-Modificado (M-CHAT) (Robins et al., 2001) at 18 months old. At 12 months, the presence of ASD early signs was determined by the score obtained with the FYI. A higher score was indicating a greater presence of early symptomatology. At 18 months, ASD early symptomatology was determined by the presence/absence of early markers, obtained from the application of the M-CHAT (Robins et al., 2001). Data analysis was performed using the statistical analysis program SPSS, version 24.0 (Cor, 2016). Descriptive analyses, correlational analyses, MANOVA, multiple linear regressions and logistic regressions were conducted. The results showed statistically significant correlations between some of the early social communication measures at 8, at 12 and at 18 months. The most noteworthy significant correlations were the following. IJAL and IJAH showed a statistically significant correlation: they correlated positively at 8 months and negatively at 12 months. IJAL and IBRL correlated significantly at 8 months, while their higher-level analogues (IJAH and IBRH) correlated significantly at 12 months. IJAL and RJAP correlated significantly at 8 and 18 months. RJAP and RJAD correlated significantly at 8 and 12 months of age. Finally, ISI and RSIT correlated significantly at 8 months. Regarding the evolution of the early social communication variables, the results indicated that they present different onsets and different growth patterns. IJAL and RJAP are behaviours with an early onset. That is why their growth pattern was flat, with average scores that remained high throughout the three moments. The differences between the moments were not significant for IJAL (8-12 months, 12-18 months and 8-18 months). Regarding RJAP, only the differences between 12 and 18 months were significant. IBRL presented an increase from 8 to 12 months, and a slight decrease from 12 to 18 months. The differences between the moments were significant in all cases for IBRL (8-12 months, 12-18 months and 8-18 months). IJAH, RJAD, IBRD and RBRT presented a generally growing pattern: a zero-average score at 8 months, and an increase between 8 and 12 months and between 12 and 18 months. The differences between the moments were significant in all cases for these variables (8-12 months, 12-18 months and 8-18 months). ISI and RSIT showed a low starting point at 8 months, an increase from 8 to 12 months and a flat pattern from 12 to 18 months. The differences were significant between 8 and 12 months and between 8 and 18 months for ISI and RSIT. Regarding the relationship between early social communication and early ASD signs, the results showed that no measures at 8 months old could significantly predict ASD early symptomatology at 12 months old. However, ASD early markers at 18 months were predicted by IJA and ISI measures at 8 months, and by RJA measures at 12 months. Finally, the results revealed that RJAD measures at 8 months could significantly predict word comprehension at 12 months, while RJAD measures at 12 months could significantly predict vocalization behaviours at 18 months. In summary, it seems that difficulties of joint attention at 8 and 12 months old can be an indicator of the presence of early ASD signs at 18 months. At 8 months, the variables that most informed about this early symptomatology were the initiating joint attention variables. At 12 months, the variables that most informed about this early symptomatology were the responding joint attention variables. With respect to linguistic competence, responding to distal joint attention showed to be one preverbal communication behaviour significantly related to subsequent linguistic competence. It was related to vocabulary at 12 months old, and to vocalization behaviours at 18 months old. This is an investigation that can contribute to a better understanding of the role of early social communication in language development and early detection of ASD. It can be a contribution for future research focused on early detection and intervention. Early intervention is of special interest because, e

    Delineamento experimental em blocos incompletos : estudo de casos particulares

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    Dissertação de Mestrado em Estatística, Matemática e Computação apresentada à Universidade AbertaO Delineamento Experimental em Blocos Incompletos reveste-se de uma enorme importância uma vez que faz a ponte entre a matemática aplicada e as aplicações da estatística em áreas tão diversas como a agricultura, a medicina, a biometria, a criptografia, a genética, a indústria, as ciências da educação, entre muitas outras. Tem por objetivo principal a obtenção da maior quantidade de informação possível, a partir de uma pesquisa experimental. Para tal, procede-se a uma análise comparativa entre as diferentes variedades ou tratamentos por forma a se poderem controlar as fontes de variação aleatórias através da divisão das unidades experimentais em blocos. Seguidamente, procede-se à síntese de cada um dos capítulos: No primeiro capítulo deste trabalho é feita uma introdução ao delineamento experimental em blocos. É também exposta a motivação para a abordagem desta temática. No segundo capítulo apresenta-se uma introdução histórica ao delineamento experimental em blocos. É também desenvolvido com algum detalhe o estudo dos planos em blocos incompletos equilibrados. No terceiro capítulo procede-se à investigação de casos particulares, nomeadamente dos planos com blocos repetidos, planos com diferentes dimensões e planos com número de réplicas variável, passando de seguida à classificação em famílias dos planos com repetições (BIBDR) - Balanced Incomplete Block Designs with Repeated Blocks (Planos em Blocos Incompletos Equilibrados com Repetições). A construção dos (BIBD) - Balanced Incomplete Block Designs com Repetições (BIBDR) é abordada como um Plano Otimal que proporciona facilidade de aplicação prática e se reveste de importância sob o ponto de vista económico, (Foody, W. & Hedayat, A, 1977), (Hedayat, A. S. & Hwang, H. L. 1984). Foi desenvolvido um programa em Basic para obtenção da lista de parâmetros dos possíveis BIBDR, com dimensão de bloco sete, tendo em conta as condições necessárias de construção dos BIBDR sobre certas restrições. Os planos são classificados atendendo às três famílias de BIBDR, definidas em (Hedayat, A. S. & Hwang, H. L. 1984). O capítulo quatro explora as ligações existentes entre desenho experimental, matrizes de Hadamard e o risco de perda de dados nos Códigos QR. No capítulo cinco aprofunda-se o estudo dos Códigos QR, explorando diversas aplicações e apresentando exemplos práticos. No capítulo seis expõe-se uma introdução ao software estatístico R (Project for Statistical Computing) e exemplos práticos desenvolvidos neste, tendo por base a temática do delineamento experimental com blocos. O capítulo sete apresenta diversos trabalhos de investigação com abordagens recentes ao delineamento experimental em blocos. Estes trabalhos abrangem temáticas diversas como a medicina, criptografia, ensaios clínicos, Códigos QR entre outros. Neste capítulo, destaca-se um estudo sobre a doença de Parkinson no âmbito dos ensaios clínicos. A aplicação prática presente no capítulo oito mostra a análise de fiabilidade inter-examinador inspirada nesse estudo. Nesta aplicação serão analisados seis neurologistas que examinam dez pacientes com Parkinson. No capítulo nove são sintetizadas algumas considerações finais e apresentadas perspetivas de investigação futura.The Design of Experiments considering incomplete blocks is of great importance since it bridges the gap between Applied Mathematics and Applications of Statistics in diverse areas such as agriculture, medicine, biometrics, encryption, genetics, industry and science education, among many others. The Design of Experiments or Experimental Design has the main objective of obtaining as much information as possible from an experimental study. A comparative analysis of the different varieties or treatments is made, in order to be able to control the random sources of variation by dividing the experimental units in blocks. Subsequently, we will synthesize each one of the chapters: In the first chapter of this paper an introduction to Experimental Design in blocks is presented. It is also exposed the motivation to address this issue. The second chapter presents a historical introduction to Experimental Design in blocks. It is also approached the study of balanced incomplete block designs and respective characteristics. In the third chapter a research of special cases is developed, such as designs with repeated blocks, designs with different dimensions and designs with different number of replicas, followed by the classification in families of BIB designs with repetitions. The construction of BIBD with Repetitions (BIBDR) is carried out using Optimal Designs which provide ease of practical application and is of great importance from the economical point of view, (Foody, W. & Hedayat, A. 1977), (Hedayat, A. S. & Hwang, H. L.1984). A program in BASIC language has been developed in order to obtain the list parameter of possible BIBDR with seven block size, taking into account certain restrictions. These designs are classified according to the three families of BIBDR defined in (Hedayat, A. S. & Hwang, H. L.1984). Chapter four explores the links between Experimental Design, Hadamard matrices and the risk of data loss in QR Codes. Chapter five deepens the study of QR Codes, exploring different applications and presenting practical examples. Chapter six presents an introduction to statistical software R (Project for Statistical Computing) and practical examples developed in this, based on the theme of Experimental Design with blocks. The seventh chapter presents recent approaches and applications of Experimental Design considering blocks. These works cover different topics such as medicine, encryption, clinical tests, QR Codes and more. The approach of the previous section on clinical studies highlighted a study of Parkinson's disease. Chapter eight shows a virtual practical application of this, in the analysis of an inter reliability inspired in this study. In this application a design considering six neurologists who examined ten patients with Parkinson's disease will be considered. In chapter nine, some final remarks are summarized and perspectives for future research are presented

    Delineamento experimental em blocos incompletos : estudo de casos particulares

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    Dissertação de Mestrado em Estatística, Matemática e Computação apresentada à Universidade AbertaO Delineamento Experimental em Blocos Incompletos reveste-se de uma enorme importância uma vez que faz a ponte entre a matemática aplicada e as aplicações da estatística em áreas tão diversas como a agricultura, a medicina, a biometria, a criptografia, a genética, a indústria, as ciências da educação, entre muitas outras. Tem por objetivo principal a obtenção da maior quantidade de informação possível, a partir de uma pesquisa experimental. Para tal, procede-se a uma análise comparativa entre as diferentes variedades ou tratamentos por forma a se poderem controlar as fontes de variação aleatórias através da divisão das unidades experimentais em blocos. Seguidamente, procede-se à síntese de cada um dos capítulos: No primeiro capítulo deste trabalho é feita uma introdução ao delineamento experimental em blocos. É também exposta a motivação para a abordagem desta temática. No segundo capítulo apresenta-se uma introdução histórica ao delineamento experimental em blocos. É também desenvolvido com algum detalhe o estudo dos planos em blocos incompletos equilibrados. No terceiro capítulo procede-se à investigação de casos particulares, nomeadamente dos planos com blocos repetidos, planos com diferentes dimensões e planos com número de réplicas variável, passando de seguida à classificação em famílias dos planos com repetições (BIBDR) - Balanced Incomplete Block Designs with Repeated Blocks (Planos em Blocos Incompletos Equilibrados com Repetições). A construção dos (BIBD) - Balanced Incomplete Block Designs com Repetições (BIBDR) é abordada como um Plano Otimal que proporciona facilidade de aplicação prática e se reveste de importância sob o ponto de vista económico, (Foody, W. & Hedayat, A, 1977), (Hedayat, A. S. & Hwang, H. L. 1984). Foi desenvolvido um programa em Basic para obtenção da lista de parâmetros dos possíveis BIBDR, com dimensão de bloco sete, tendo em conta as condições necessárias de construção dos BIBDR sobre certas restrições. Os planos são classificados atendendo às três famílias de BIBDR, definidas em (Hedayat, A. S. & Hwang, H. L. 1984). O capítulo quatro explora as ligações existentes entre desenho experimental, matrizes de Hadamard e o risco de perda de dados nos Códigos QR. No capítulo cinco aprofunda-se o estudo dos Códigos QR, explorando diversas aplicações e apresentando exemplos práticos. No capítulo seis expõe-se uma introdução ao software estatístico R (Project for Statistical Computing) e exemplos práticos desenvolvidos neste, tendo por base a temática do delineamento experimental com blocos. O capítulo sete apresenta diversos trabalhos de investigação com abordagens recentes ao delineamento experimental em blocos. Estes trabalhos abrangem temáticas diversas como a medicina, criptografia, ensaios clínicos, Códigos QR entre outros. Neste capítulo, destaca-se um estudo sobre a doença de Parkinson no âmbito dos ensaios clínicos. A aplicação prática presente no capítulo oito mostra a análise de fiabilidade inter-examinador inspirada nesse estudo. Nesta aplicação serão analisados seis neurologistas que examinam dez pacientes com Parkinson. No capítulo nove são sintetizadas algumas considerações finais e apresentadas perspetivas de investigação futura.The Design of Experiments considering incomplete blocks is of great importance since it bridges the gap between Applied Mathematics and Applications of Statistics in diverse areas such as agriculture, medicine, biometrics, encryption, genetics, industry and science education, among many others. The Design of Experiments or Experimental Design has the main objective of obtaining as much information as possible from an experimental study. A comparative analysis of the different varieties or treatments is made, in order to be able to control the random sources of variation by dividing the experimental units in blocks. Subsequently, we will synthesize each one of the chapters: In the first chapter of this paper an introduction to Experimental Design in blocks is presented. It is also exposed the motivation to address this issue. The second chapter presents a historical introduction to Experimental Design in blocks. It is also approached the study of balanced incomplete block designs and respective characteristics. In the third chapter a research of special cases is developed, such as designs with repeated blocks, designs with different dimensions and designs with different number of replicas, followed by the classification in families of BIB designs with repetitions. The construction of BIBD with Repetitions (BIBDR) is carried out using Optimal Designs which provide ease of practical application and is of great importance from the economical point of view, (Foody, W. & Hedayat, A. 1977), (Hedayat, A. S. & Hwang, H. L.1984). A program in BASIC language has been developed in order to obtain the list parameter of possible BIBDR with seven block size, taking into account certain restrictions. These designs are classified according to the three families of BIBDR defined in (Hedayat, A. S. & Hwang, H. L.1984). Chapter four explores the links between Experimental Design, Hadamard matrices and the risk of data loss in QR Codes. Chapter five deepens the study of QR Codes, exploring different applications and presenting practical examples. Chapter six presents an introduction to statistical software R (Project for Statistical Computing) and practical examples developed in this, based on the theme of Experimental Design with blocks. The seventh chapter presents recent approaches and applications of Experimental Design considering blocks. These works cover different topics such as medicine, encryption, clinical tests, QR Codes and more. The approach of the previous section on clinical studies highlighted a study of Parkinson's disease. Chapter eight shows a virtual practical application of this, in the analysis of an inter reliability inspired in this study. In this application a design considering six neurologists who examined ten patients with Parkinson's disease will be considered. In chapter nine, some final remarks are summarized and perspectives for future research are presented

    Aerospace Medicine and Biology: A cumulative index to the 1982 issues

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    This publication is a cumulative index to the abstracts contained in the Supplements 229 through 240 of Aerospace Medicine and Biology: A continuing Bibliography. It includes three indexes: subject, personal author, and corporate source
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