Texte remanié de: Doct. diss.--New York, 1985. / Bibliogr. p. 234-251.

No description available.

Since the introduction of the Griffiths Scales of Mental Development (Griffiths Scales) in the United Kingdom (1950) and South Africa (1977) they have become widely used and researched, both at a national and international level. Studies completed in South Africa have demonstrated the invaluable role the Griffiths Scales have fulfilled in the assessment of South African children of all cultural and socio-economic groups. However, research has indicated a need for the revision of the scales specifically relating to social and cultural factors that influence performance. The aim of this study was two-fold , namely: (i) to revise the 20 small pictures and the large picture of the Hearing and Speech Scale of the Griffiths Scales, making them more culturally relevant for the children of our contemporary world, and especially in South Africa; and (ii) to describe the performance of South African children, between 60 and 83 months of age, utilizing the revised pictures. For the qualitative component of the study a questionnaire pertaining to the small and large “Experimental pictures” was completed by the participants. The participants consisted of the executive committee members of the ARICD in the United Kingdom. Additionally 17 “expert “ Griffith's users and “lay-experts” working in early childhood development throughout South Africa, were included. Their responses were content analyzed and incorporated into the Experimental pictures. This resulted in the development of the Revised Griffiths pictures. The quantitative component of the study utilized two sample pools. Sample 1 (n=204) and Sample 2 (n=180) were comprised of pre-school children aged between 60 and 83 months. Sample 1 was utilized for the 20 small revised pictures and the large revised SA picture, while sample 2 was utilized for the 20 small revised pictures and the large revised United Kingdom/ European/Australian picture. Furthermore, both samples, consisted of children from all cultural, socio-economic, language, and gender groups. x The major findings of the present study were as follows: 1. Referring to sample 1, only the White and Indian pre-schoolers correctly identified a mean number of small pictures above that which was proposed by Griffiths (1960). The Coloured pre-schoolers almost identified Griffiths (1960) proposed number. 2. Referring to sample 2, all excepting the Black pre-schoolers correctly identified Griffiths’ (1960) proposed mean of small pictures. 3. All children from sample 1 and sample 2 were able to identify more stimuli from the large revised pictures, than was proposed by Griffiths (1960). 4. All four cultural groups from samples 1 and 2, elicited a mean number of descriptive words below Griffiths’ (1960) proposed criteria. 5. White pre-schoolers from sample 1 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 6. White and Coloured pre-schoolers from sample 2 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 7. All four cultural groups from sample 1 and sample 2, elicited a mean number of personal or possessive pronouns below Griffith's (1960) proposed criteria. 8. A general trend noted for the four cultural groups of both samples, was that the percentage of children who passed successive age-appropriate items, did not decrease stepwise as would be expected from the placement of items in order of difficulty. In view of the latter finding, it is recommended that for South African children the placement of the items for the small and large pictures of the Hearing and Speech Scale should be revised in terms of their order of difficulty. It is furthermore recommended that separate norms for South African children be established for the Hearing and Speech Scale

Alan Griffiths was born at Walton-on Thames, England in 1906. He was educated at Christ's Hospital and later at Oxford (under the tutelage of C.S. Lewis). At Oxford he read English literature and philosophy. After considerable inner turmoil he was converted to Christianity in 1931 and entered the Roman Catholic Church in 1933. As a novice Benedictine he was given the name Bede, and was finally ordained as a priest 1940. In 1955 Fr Bede went to India to start a Benedictine community with Dom Benedict Alapatt. He later moved to Kurisumala Ashram in Kerala, and finally, in 1968, to Shantivanam Ashram in Tamil Nadu. He died at Shantivanarn in 1993. Fr Bede was, and still is, regarded by many as a spiritual pioneer. This high regard stems from an appreciation of his spirituality which was rooted in a mystical experience of God. This thesis investigates aspects of Fr Bede's cosmic christology as they arise from his spirituality. The aim of this research is to show that Fr Bede’s cosmic christology that stems from an expression of a real mystical experience of Christ, as the source, sustainer and goal of the whole cosmos, offers both value and insight to Christian spiritual practice and the formulation of doctrine. What makes Fr Bede's spirituality so valuable is the manner in which he integrated East and West in his spirituality and person, coupled with his ability to draw upon that integration in reflecting and articulating his experience - which ultimately shaped his cosmic christology. In order to share his knowledge and experience of the cosmic Christ, Fr Bede draws upon linguistic and philosophical concepts from the East (and Hinduism in particular) as well as the language and theory arising from discoveries in the areas of quantum physics, microbiology and transpersonal psychology in the West. It is the primacy of spiritual experience, coupled with Fr Bede's ability to integrate the religions, cultures and world-views of the East and West within himself, which makes his cosmic christology so compelling.

Child assessment has become imperative today as parents and teachers recognize the need for early diagnostic assessments to adequately cater for children’s’ diverse and growing needs so that children can benefit from services and attention in a psychological or educational setting. The Griffiths Mental Development Scales, an established and well-researched instrument is reported to be one of the most carefully designed measures of child development . Studies in various parts of the world have demonstrated that the Griffiths Scales are applicable to diverse populations and that they tap experiences that are common to different cultures. The recent revision and restandardisation of the Griffiths Mental Developmental Scales-Extended Revised (GMDS-ER) has necessitated investigations into its psychometric properties. In view of the important role that assessment measures play in the early identification of developmental delays, it is important that assessment measures are reliable and valid for their intended purpose(s). This study, which is part of a larger research project, attempted to explore and add further evidence of the construct validity of one of the six Subscales of the GMDS-ER, namely the Personal-Social Subscale (Subscale B). An exploratory-descriptive design using a triangulation approach was utilized to explore the construct validity of the Personal-Social Subscale. A nonprobability purposively selected sample of 18 experts working with children participated in the facet analysis to identify the constructs underlying Subscale B (the qualitative aspect of the study). The sample for the quantitative aspects of this study (i.e., the empirical validation of the identified constructs) was collected as part of the broader restandardisation and represented a stratified random sample of 1026 children between the ages of 3 and 8 years from across the United Kingdom and Eire. Three measures, namely a biographical questionnaire, the GMDS-ER and a construct evaluation form were used to gather the qualitative and quantitative data. The qualitative data was analysed by means of facet analysis and literature control. The quantitative data was analysed by using exploratory common factor analysis using oblique (DQUART) rotation to empirically verify the qualitatively identified construct model by specifying a onefactor solution for each underlying construct.

Les manganites ont été particulièrement étudiés ces dernières années pour leurs propriétés de magnétorésistance colossale (CMR) et l'effet magnétocalorique. Ces oxydes de formule chimique T1-xDxMnO3, (T: terre-rare, D: alcalino-terreux) de structure pérovskite ABO3, présentent une valence mixte Mn3+/Mn4+. Les facteurs clés qui contrôlent les propriétés physiques sont le rayon moyen du site A (), le désaccord de taille des cations du site A (quantifié par la variance σ2 et la valence mixte du manganèse. Lors de notre étude, nous nous sommes focalisés sur l'effet du désordre gelé crée par la substitution aléatoire dans le site A de la structure pérovskite. Des échantillons poly-cristallins ont été synthétisés à cette fin. Les systèmes étudiés sont La0,8Pb0,1□0,1MnO3 et La0,8Pb0,1Na0,1MnO3 de composé mère La0,8Pb0,2MnO3 et La0,7Pb0,05Na0,25MnO3 de composé mère La0,7Pb0,3MnO3. Pour les deux premiers matériaux, l'étude structurale magnétique et électrique est présentée par ce manuscrit. Cette étude a permis de montrer l'existence des clusters ferromagnétique à haute température dans le contexte de la formation de la phase de Griffiths. De plus, nous avons mis en évidence l'existence des excitations magnétiques des ondes de spin à très basses température. A partir de la variation dans la température de Curie, la variation de la constante de raideur de l'onde de spin et l'évolution de la phase de Griffiths, nous avons pu montrer que le matériau La0,8Pb0,1□0,1MnO3 présente le rayon le plus faible et σ 2 le plus élevé comparé à La0,8Pb0,1Na0,1MnO3. Cette étude à montrer que le désordre est le mécanisme influençant sur les propriétés physiques de ces matériaux. Pour le système La0,7Pb0,05Na0,25MnO3, qui présente une température de Curie élevée (au dessus de l'ambiante) les propriétés magnétique ne montrent pas un effet considérable du désordre il est considéré régi par le mécanisme du double échange. Dans ce travail, nous nous sommes aussi intéressés à l'influence du désordre sur les exposants critiques et à l'effet magnétocalorique. L'analyse montre que les exposants critiques pour La0,8Pb0,1□0,1MnO3 sont proches à ceux du modèle de Heisenberg à dimension 3, alors qu'ils sont proches de ceux de la théorie du champ moyen pour La0,8Pb0,1Na0,1MnO3. Le désordre est quantifié d'être corrélé à court-distance ou non corrélé. Pour La0,7Pb0,05Na0,25MnO3, les exposants critiques appartiennent à la classe d'universalité de Heisenberg, comme prévu théoriquement. L'étude de l'effet magnétocalorique montre des valeurs intéressantes pour la variation d'entropie magnétique et la puissance relative du froid pour La0,7Pb0,05Na0,25MnO3. De plus, le caractère inhomogène de ces trois composés est affirmé par l'étude de l'exposant locale n qui varie avec le champ magnétique pour toute la gamme de température étudié. / Manganites have been extensively studied over the past several years, a result of their displaying a colossal magnetoresistance (CMR) and the magnetocaloric effect (MCE). These materials with a perovskite structure (ABO3) are characterized by the general formula T1- xDxMnO3, (T: rare earth, D: alkaline earth), x being the doping level, the latter causing changes in the valence state of the Mn ions to maintain charge neutrality. The key parameters that control the physical properties of these oxides are the mean radius of the site A (), the size mismatch of cations of the site A (quantified by the variance σ 2) and the mixed valence of manganese. In our study, we focused on the effect of the quenched disorder created by the random substitution in the A site of the perovskite structure. Polycrystalline samples were synthesized for this purpose. The systems studied are La0,8Pb0,1□0,1MnO3 and La0,8Pb0,1Na0,1MnO3 have a parent compound La0,8Pb0,2MnO3 and La0,7Pb0,05Na0,25MnO3 with parent compound La0,7Pb0,3MnO3. For the first two materials, structural, electrical and magnetic studies are presented in this manuscript. These studies reveal the existence of ferromagnetic clusters at high temperature in the context of the formation of the Griffiths phase. In addition, we have demonstrated the existence of magnetic excitations of spin waves at very low temperature. From the variation of the Curie temperature, the variation of the stiffness constant of the spin wave and the evolution of the Griffiths phase, we have shown that the material La0,8Pb0,1□0,1MnO3 has the lowest and highest σ2 compared to La0,8Pb0,1Na0,1MnO3. These studies showed that the disorder is the mechanism influencing the physical properties of these materials. For the system, La0,7Pb0,05Na0,25MnO3, which has a high Curie temperature (above ambient) magnetic properties do not show a significant effect of the disorder, which is considered to be governed by the mechanism of double exchange. In this work, we are also interested in the influence of disorder on the critical exponents and the magnetocaloric effect. The analysis shows that the critical exponents for La0,8Pb0,1□0,1MnO3 are close to those of the Heisenberg model in three dimensions, while they are very close to those of mean field theory La0,8Pb0,1Na0,1MnO3. The disorder is quantified to be correlated with short-range or uncorrelated. For La0,7Pb0,05Na0,25MnO3, the critical exponents belong to the Heisenberg universality class, as expected theoretically. The study of magnetocaloric effect shows interesting values of the magnetic entropy change and the relative cooling power La0,7Pb0,05Na0,25MnO3. In addition, the inhomogeneous nature of these three compounds is confirmed by the study of the local exponent “n” which varies with the magnetic field for the entire temperature range studied.

Nesta tese estudamos os efeitos da desordem espacial e temporal na transição de fase entre a sobrevivência e extinção de populações biológicas. Na primeira parte estudamos um modelo epidemiológico com quatro estados. Apesar deste modelo não conter desordem, concluímos que seu comportamento crítico é o mesmo do processo de contato com desordem (espacial) quenched. Na segunda parte estudamos o movimento Browniano fracionário refletido, onde vimos que a combinação dos efeitos do ruído com correlações de longo alcance e a parede refletora cria uma singularidade em lei de potência na densidade de probabilidade da posição do caminhante. Por fim, estudamos a equação logística com desordem temporal através do mapeamento no movimento Browniano fracionário refletido. Neste último estudo vimos como as correlações de longo alcance mudam o comportamento crítico deste sistema. / We have studied the effects of spatial and temporal disorder at the phase transition between survival and extinction of biological populations. In the first part we studied a four states biological population model. Despite having no disorder, we have seen that its critical behavior is the same of the contact process with (spatial) quenched disorder. In the second part, we studied the reflected fractional Brownian motion, where the interplay between the correlated noise and the reflecting wall results in a power-law singularity in the probability density of the position of the walker. Finally, we deduced the critical properties of the logistic equation with temporal disorder by mapping it onto the reflected fractional Brownian motion. This mapping allow us to understand how long-range correlations change the critical behavior of this system.

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The Association for Research in Infant and Child Development (ARICD) is currently in the process of revising the Griffiths Scales. When revising measures, obtaining practitioners’ views on the measure is common practice. The purpose of the present study was to explore the themes emerging from a group of practitioners surveyed on their opinions about the Griffiths Scales in order to inform the Griffiths Scales revision process. A qualitative, survey methodology was used. A survey questionnaire was designed and distributed by the ARICD to ascertain practitioners’ and researchers’ views on assessing child development, insights into practicalities and the usability of the Griffiths Scales, as well as their opinions on potential changes and improvements. Data were also gathered on the frequency, purpose and age range with which practitioners used the Griffiths Scales. The questionnaire was distributed to Registered Griffiths Scales Users (practitioners) via the ARICD members’ email distribution list. The practitioners and researchers were either current or past users of the Griffiths Scales. Eighty-five completed questionnaires were returned of which 52 were from current, regular users of the Griffiths Scales and 33 were from non-users. The data obtained from the 85 returned questionnaires were analysed in the present research study using thematic analysis to extract themes for both users and non-users of the Griffiths Scales. The results of the data analysis revealed four over-arching themes, namely, purpose and use of the Griffiths Scales; domains, content, and structure of the Griffiths Scales; psychometric properties, standardisation, and norms; and merits, limitations, and improvements. Based on the themed views of practitioners, recommendations were made regarding the support for the next revision cycle as well as strengths of the Griffiths Scales that should be retained and improvements and additions needed. It is hoped that these recommendations will guide aspects of the revision process. Consequently, the recommendations have been submitted to the Project Board.

In this unique time of nation building in South Africa, education is seen as the key foundation stone to prosperity and development. However, despite a decade of restructuring, many differing groups of children still do not receive the quality of education they deserve. Amongst those are children with special needs, including those who have a hearing impairment. These children are the focus of the present study. It is a widely accepted principle that early assessment and intervention is necessary to maximise a child’s potential. It is for this reason that the global aim of this study was to explore and describe the developmental profile of hearing impaired children on the Revised Extended Griffiths Scales. Further aims were to compare the performance of the clinical sample to a normal South African sample. A quantitative, exploratory-descriptive research design was employed. The sample of hearing impaired children (N = 58), between the ages of 36 and 95 months, attended the Carel du Toit Pre-School in the Western Cape, South Africa and were obtained by means of a non-probability, purposive sampling procedure. The normal sample (N = 58) was drawn from an existing database created for the revision of the Scales. Information was collated using clinical files, biographical data as well as the results of an assessment on the Revised Extended Griffiths Scales. The major findings of the study are summarised below. The general performance of the hearing impaired sample on the Revised Extended Griffiths Scales was average. The performance of the children on the six subscales ranged from below average to average, with major fall-outs occurring on the Hearing and Speech and Practical Reasoning Subscales. The normal sample performed significantly better than the hearing impaired sample on all of the subscales of the measure. However, significant differences were found on four of the six subscales, namely, the Locomotor, Personal-Social, Hearing and Speech and Practical Reasoning Subscales. Generally, the results of the current study suggest that a specific developmental profile is obtained for hearing impaired children. In addition, this study has highlighted the success with which the Revised Extended Griffiths Scales can be utilised on a hearing impaired population.