This study approaches wood quality in young trees by very early screening – and consequent selection for propagation – on the basis of physical and mechanical properties. In chapter 1 corewood properties are reviewed and the importance and problems associated with early screening are discussed. Due to randomly distributed reaction wood in young trees it is advantageous to lean trees to avoid intermixing of the two wood types and minimise any uncertainty in the results. In chapter 2 physical and mechanical properties are described for opposite and compression wood in a population of Pinus radiata comprising of 50 families, at a young (<3 years) age. The dynamic stiffness was determined using the resonance acoustic technique. Density was measured using water displacement method, and longitudinal and volumetric shrinkage were measured from green to ~5% moisture content. The compression wood and opposite wood differ significantly in all the measured properties. Compression wood was characterised by high density and high longitudinal shrinkage. The mean stiffness of opposite wood was 3.0 GPa with a mean standard deviation of 0.39, and the mean longitudinal shrinkage of opposite wood was 0.99% with mean standard deviation of 0.31 across the samples examined. This variation in stiffness and longitudinal shrinkage in opposite wood can be exploited to screen for wood quality. The variation in stiffness and longitudinal shrinkage within a family was comparable to variation among families. In spite of large within site variability it was possible to distinguish between the worst and the best families in opposite wood at young age. In chapter 3 ranking of selected families of Pinus radiata was done based on microfibril angle, which is considered as the main factor influencing both stiffness and longitudinal shrinkage. The ranking was compared with ranking done using acoustic velocity which is more practical and fast method of screening trees. The mean MFA in opposite wood was 39° with a mean standard deviation of 3.7 and in compression wood the mean MFA was 44° with a mean standard deviation of 2.9. The variation in MFA in opposite wood offers opportunities to breed for trees with low MFA. A strong negative correlation (R=-0.68) between acoustic velocity squared and MFA in opposite wood suggested that the resonance technique can be used effectively to screen very young wood rather than using MFA. At high MFA, the cell wall matrix also plays an important role in determining the mechanical and physical properties of the wood. At present the chemical composition of wood samples is determined by wet chemical analysis, which is time consuming and laborious. Therefore, it is impractical to characterise large numbers of samples. Mechanical properties, particularly tanδ (dissipation of energy), which changes with temperature and frequency as the structure of the material changes at the molecular level, was studied using dynamic mechanical analysis (DMA). The idea was to assess if it can be used as a quality trait for tree screening instead of wet chemical analysis. Compression wood and opposite wood were characterised for storage modulus and tanδ at constant moisture content. In practice the instrument used, TA instrument Q800, was unable to provide the desired range of temperature and humidity so no glass transition at 9% moisture content in the temperature range of 10°C to 85°C at 1 and 10 Hz frequency was observed that might be attributed to the hemicelluloses (or lignin). In spite of the huge difference in chemical composition of opposite and compression wood, the difference in their mean tanδ at 25°C and 1 Hz values was just 7%. The positive correlation between MFA and tanδ in opposite wood suggested that MFA also plays a role in the dissipation of energy. The strong relationship between storage modulus and dynamic modulus (R=0.74) again justifies the reliability of resonance technique to screen young wood for stiffness. Concurrently eighty seven, two-year-old leant Eucalyptus regnans were studied for growth strains along with other physical and mechanical properties, independently in tension and opposite wood. The leant trees in Eucalyptus regnans vary in their average growth strain. Strong correlation between measured and calculated strain (R=0.93) suggests that the quick split method can be used to screen large populations for growth stresses. Tension wood was characterised by high density and was three times stiffer than opposite wood and twice as high in volumetric shrinkage. The high longitudinal shrinkage in opposite wood could be due to comparatively high MFAs in opposite wood of the young trees. There was no correlation between growth strain values and other measured properties in opposite wood. It is possible to screen for growth strain at age two, without any adverse effect on stiffness and shrinkage properties.

The purpose of this study was to compare thirty-two childrens' performances on the Daberon-2 Screening for School Readiness and the Early Screening Inventory , as well as determine whether there was a correlation between the tests. This study responded to the needs of the local Portland, Oregon area schools, some of which use these tests, to investigate the tests, and explore the possibility of using the shorter ESI over the longer Daberon. The reasoning behind the goal of the study was to determine that if the two tests showed a strong, positive correlation and identified the same children as needing further assessment, then perhaps the test which was shorter to administer could be used with confidence as a faster, but equally reliable 2 pre-kindergarten screening tool. In other words, if a child "passes" the Daberon, one could assume that the child would most likely "pass" the ESI as well. Based on the results of this study, one can make this assumption with a reasonable amount of confidence. The subjects in this study included 16 males and 16 females. All were preschool students, ranging in age from 4-6 to 5-6 with a mean age of 5-1 years. The subjects were given the two tests in a counterbalanced order, which also varied as to sex so that not all of one sex received one test first. The standard scores and whether or not each subject "passed" or "failed" each screen was determined. The correlation between the two tests was also determined. The Pearson product moment correlation coefficient was used to determine the degree of relatedness between the tests. A high positive correlation of .73 was found between the Daberon and the ESI, with a shared variance

Thèse (M.A.)--Université Laval, 2009. / Bibliogr.: f. [48]-54. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

This diploma thesis deals with the possibilities of prediction of specific learning disabilities among children of preschool age. The thesis is divided into two consequent parts a theoretical part and a practical part. In the theoretical part I focus mainly on the etiology and the diagnosis of specific learning disabilities. The thesis focuses mainly on given examples of a few predictive batteries from Czech and even foreign authors. The practical part contains results of a research survey where are the data I collected through predictive battery of British authors: Nicolson and Fawcett: The Dyslexia Early Screening Test. The main objective of the diploma thesis was to find out the possibility of using this test by pedagogical workers at pre-schools in order to avoid specific learning disabilities. For the research, the quantitative research method was used.

La dynamique des classes de maternelle est de plus en plus difficile à gérer pour les enseignants puisque plusieurs enfants présentent des troubles du comportement en bas âge. Réalisé dans le cadre d'une pré-expérimentation, ce mémoire évalue la pertinence d'utiliser un instrument de dépistage précoce dans les classes préscolaires du Québec. Il s'agit du Early Screening Project, visant le dépistage des enfants de 3 à 6 ans. Le premier chapitre du mémoire présentera d'abord les connaissances actuelles concernant les troubles du comportement et le second chapitre, rédigé sous forme d'article, contient l'étude réalisée auprès d'enseignants et d'élèves de maternelle âgés de 5 ans au 30 septembre 2007. On constate que l'instrument est aisé d'utilisation et que 21 des 56 participants (environ 37 %) pourraient éventuellement être à risque de développer des comportements difficiles puisqu'ils dépassaient les normes lors des 2 premières étapes du processus qui en compte 3. Plus précisément, 16 % des 56 élèves pourraient être considérés comme étant ± sous-réactifs ¿ alors que 21 % des 56 participants seraient dans la catégorie ± sur-réactifs ¿. Les données obtenues sont plus élevées que les données américaines pour un groupe d'âge semblable.

Ce mémoire aborde en premier lieu une revue des connaissances actuelles sur les troubles du comportement au préscolaire. Il propose ensuite un survol des outils de dépistage existants et présente plus particulièrement le Early Screening Project (ESP: Walker, Severson et Feil, 1995). La seconde partie, sous forme d'article, expose les résultats d'un premier essai en milieu québécois du ESP auprès d'enfants de 4 ans participant au programme préscolaire Passe-Partout. Les résultats indiquent qu'environ 28 % des jeunes démontrent des problèmes émergents de comportement et soutiennent la pertinence d'utiliser cet outil afin d'intervenir précocement auprès des enfants du préscolaire.

Ce travail concerne le comportement de retrait relationnel du jeune enfant, sa mesure et sa validité prédictive sur la qualité du développement précoce dans ses différentes dimensions. Il représente la première synthèse de l'histoire du concept de retrait relationnel du jeune enfant, de ses liens avec les modèles animaux, avec le modèle paradigmatique du "Still Face" et de la réparation, de la dys-synchronie comme facteur majeur de la psychopathologie précoce. Le comportement de retrait relationnel prend ses racines dans la physiologie, comme mode privilégié de régulation par le bébé de l'interaction, dans une échelle micro interactive. D'une façon plus clinique et sur une échelle temporelle plus longue, il apparaît comme un mode de défense majeur face à la violation des attentes du bébé dans l'interaction. On l'observe donc de façon privilégiée dans la dépression maternelle post natale mais aussi dans toutes les circonstances psychopathologiques qui affectent les capacités parentales (par exemple et de façon très nette dans les situations de conflit et violences conjugales). Le retrait relationnel peut également être lié à des difficultés de traitement de l'information sensorielle par le bébé, à des difficultés de communication sociale, à une douleur intense prolongée, et dans la prématurité ou dans certains syndromes génétiques à une association de ces facteurs liés à l'enfant. Ce travail retrace les débuts de la construction d'un outil de mesure du retrait relationnel précoce, dans la mesure où cet outil n'existait pas en tant que tel, alors que le retrait relationnel apparaît comme un signal d'alarme important, témoignant de la difficulté du bébé de jouer le jeu relationnel à hauteur de ses capacités développementales, que ce soit pour des causes liées à lui-même, à la relation avec ses caregivers, ou aux deux. Ce travail s'ouvre par une histoire de la psychiatrie du bébé et de l'avènement de la psychopathologie développementale, car on note l'importance du symptôme retrait dans cette histoire, qu'il s'agisse de l'autisme (Kanner) ou de la dépression ou de la carence précoces (Spitz), puis un historique de concept de retrait relationnel précoce : contexte clinique modèles animaux, biologie, la Construction et validation de l'échelle Alarme Détresse bébé (ADBB à 8 items) puis celle de la m-ADBB à 5 items, puis par la Psychopathologie du retrait relationnel durable, et Les développements et les applications de l'échelle ADBB : m-ADBB, effets à terme du retrait, études longitudinales, la prématurité comme analyseur du développement, dépistage précoce de l'autisme et enfin les projets en cours et trois projets actuels, autour du dépistage de l'autisme, autour de l'étude des différentes analyses factorielles et de la validation de la m-ADBB, et autour des pistes génétiques et épigénétiques du comportement de retrait. Il présente les résultats des études contrôlées et publiées avec l'ADBB, en particulier celles liées à la cohorte française d'étude des facteurs de risque et de résilience du développement précoce (étude périnatale EDEN). Le comportement clinique de retrait relationnel apparaît comme le résultat d'une interaction gène environnement, basée sur la susceptibilité génétique au comportement de retrait. Celle-ci apparaît liée au système allélique 5-HTTPR. Sur le plan cognitif, la question se pose du retrait comme pari, comme choix dans une situation d'incertitude. Les études de suivi des enfants en retrait montrent l'impact sur diverses dimensions du développement, langage, intersubjectivité, régulation émotionnelle, avec la question d'une période sensible. Ceci souligne l'importance du dépistage de ce comportement en vue d'une intervention précoce adaptée à sa cause. / This work deals with social withdrawal behavior in infants, its measure and its conceptual validity, its predictive value on early development within its several dimensions. This is the first synthesis on the history of the concept of withdrawal in infant, of its links with animal models, with the still face experimental paradigm, as well as with the repair process and with interactional dys- syssynchrony as a major process in early psychopathology. Social withdrawal behavior has its roots in physiology, as privileged way used by the infant to regulate the input within the parent infant interaction, within a micro temporal scale. On a longer temporal and more clinical scale, withdrawal behavior appears as a major defense maneuver when the baby is faced with major violations of his her expectations within the relationship. It is therefore observed in a privileged way in maternal post-natal depression, but also in all circumstances which hamper parental capacities, as conjugal violence and conflict may do for instance. Social withdrawal behavior may be as well linked with difficulties in processing sensorial input in the child, or difficulties in social communication and synchrony, or be due to an intense and sustained pain, or be linked with some genetic disorder or with some association of these factors. This work retraces the construction of a scale to asses social withdrawal behavior in infants, since no such tool existed at the time, although social withdrawal behavior appears to be an important alarm signal, showing the inability of the child to play the relational game as his her developmental level allow him or her to do, be it for causes related to himself or herself, for relational causes of because of both. This work opens on a history of the development of child psychiatry and of the coming of ages of infant development. Social withdrawal behavior took a large place at the onset of this history, with the description of autism by Kanner and anaclitic depression by Spitz. Then a history of the concept of social relational withdrawal, and of the construction of the alarm distress scale (8 item) the of the short version (5 item m-ADBB), then the studies on long term effects of social withdrawal on development. We then review the application of the scale on early diagnosis of autism, on the several factor analysis with several samples, and of the several epigenetic and genetic pathways of the social withdrawal behavior. This work reviews the results of several controlled studies with the ADBB, particularly those from the perinatal French EDEN cohort. Social withdrawal behavior appears as the result of a gene interaction, based on the genetic c susceptibility for social withdrawal behavior, possibly liked with the 5-HTPPR allele system. On a cognitive level, the issue is raised of social withdrawal behavior as a choice of a risk taking position in an uncertain situation. Follow up studies show the impact of the social withdrawal behavior on several dimensions of early development, i.e. language, early development of intersubjectivity or emotional regulation.