A severe aphasia following a cerebral vascular accident is characterised by generalised deficits in most speech-language domains. The clinical dilemma remains focused on the extensive verbal speech impairment and in most cases little possibility of regaining verbal speech production. Many individuals living with severe aphasia use augmentative and alternative communication strategies to assist them in getting their communication needs met in their everyday lives. The Blissymbol system is one of the graphic symbol systems that can be used to supplement existing communication and speech strategies of the individual with little or no speech. Although the use of AAC strategies is gaining momentum in its application to severe aphasia, however, there still remain questions on how best to help these individuals learn and retain such strategies. Not only are individuals with severe aphasia faced with a memory task when learning AAC strategies such as Blissymbols, additional complexity to AAC interventions is derived from clinical presentation of severe aphasia. The presence of extensive damage to the neural centers responsible for linguistic processing and semantic retrieval makes learning of new AAC strategies all the more complicated. Research studies have looked at whether individuals with severe aphasia can learn to recognise and retain Blissymbols. Although these studies have successfully shown that individuals with severe aphasia can learn Blissymbols, there is little information available regarding how these symbols can best be taught and retained over time individuals with severe aphasia. Recently the research that has looked at the application of symbol learning with persons presenting with severe aphasia using computer technology and sophisticated application software has highlighted the importance of therapeutic methods that may enhance the learning of such software. This study looks at the application of the self-generation effect as a viable method for enhancing the recognition of Blissymbols in persons presenting with severe aphasia. The self-generation effect is the finding of superior retention and recall for stimuli constructed or generated by an individual. Memory for stimuli such as words, numbers and pictures were found to be enhanced by the extent to which the individual was involved in its construction. Using a 2X2X3 factorial design, this study compared the recognition levels for Blissymbols taught using two treatment approaches which was the self-generation condition and the non self-generation condition. During three experimental sessions which included two withdrawal periods participants were taught using both treatments to recognise a set of Blissymbols. Recognition levels were tested during recognition probes and retention probes. The results from these probes were compared in order to identify which treatment produced superior recognition levels. The data analysis conducted showed that although there was no recognition advantage for the self-generation effect seen during the three recognition probes some advantage for the self-generation effect was seen during the retention probes conducted. The self-generation effect began to emerge by the final retention probe following a withdrawal period of seven days. The self-generation treatment showed better retention of symbol recognition over time. Previous studies have shown that the self-generation effect failed to emerge with stimuli that were new or unfamiliar. This trend was also seen in this study. The results provide support for a semantic-association theory for the self-generation effect. / Thesis (PhD)--University of Pretoria, 2010. / Centre for Augmentative and Alternative Communication (CAAC) / unrestricted

Cross-cultural differences in the perception of pictorial material has long been established and documented. In the Republic of South Africa, which is increasingly globalized, and where it is appealing from financial, economic and training perspectives, the temptation is to use Western-based AAC symbol systems and strategies in intervention with clients from other language and cultural orientations. The aim of this study was to determine the translucency ratings of specific Blissymbols as rated by six-to seven-year-old Setswana-speaking children. A secondary aim was to determine whether the ratings changed after second and third exposures in order to determine the learnability of these symbols. A brief comparison was made between the results of the current study and the results reported in the Quist et al., study (1998). Thirty-five Setswana learners were exposed to 93 selected Blissymbols, based on a study by Quist et al., (1998). A three-point semantic differential scale, consisting of three faces accompanied each Blissymbol. Participants marked the face that best described his/her perception of the specific symbol’s iconicity. This procedure was repeated over a period of three days. The results indicated that the translucency ratings of the majority of the Blissymbols ranged from moderate to high. The research further demonstrated significant differences in translucency ratings between the first and second exposures, suggesting learning of the symbols. A smaller difference was noted between Days 2 and 3. A correlation in findings was noted between the current study and the Dutch and US studies (Quist et al., 1998). / Dissertation (M (Augmentative and Alternative Communication))--University of Pretoria, 2007. / Centre for Augmentative and Alternative Communication (CAAC) / MA / unrestricted

The diploma thesis follows up on the bachelor thesis and deals with the issue of light-transmitting concrete LTC. The aim of thesis determines the transparency and its decrease due to durability. The terotical part deals with extension of LTC issues and follows up reserch from bachelor thesis. The teory is also focused on the issue of glass optical fibers. The experimental part deals with the influence of selected durability test on transparency of LTC. Transparency is determined by mesuring devise called black box. In the conclusion is summarized influences witch affects transparency and evaluation of whether the selected fibers are suitable for outdoor use.

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Objetivo: analisar o resultado das gestações e pós-natal dos fetos com translucência nucal (TN) aumentada. Método: Duzentos e setenta e cinco fetos com TN aumentada foram avaliados no setor de Medicina Fetal da Clínica Obstétrica do HC-FMUSP, com análise do cariótipo, ultra-sonografia seriada, ecocardiografias fetal e pós-natal e avaliação clinica genética pós-natal. Resultados: 14,2% apresentaram cariótipos alterados e 85,8% normais. A ultra-sonografia morfológica esteve alterada em 73,1% dos casos com cariótipo anormal e em 24,7% dos normais, destes, um terço apresentou malformações estruturais maiores, sendo 35,7% cardíacas. Resultados gestacionais adversos, como abortamento, óbitos intra-útero e neonatal ocorreram em 76,5% dos fetos com anomalias cromossômicas e em 10,2% com cariótipos normais. A avaliação pós-natal foi realizada em 72,7% das crianças, mostrando-se alterada em 14,8% dos casos. A freqüência de criança viva e saudável diminuiu com a medida da TN, que variou de 37,5%, nos casos com cariótipos normais, a 18,8% com cariótipos desconhecidos, quando a TN foi igual ou maior que 4,5 mm. Conclusão: Quanto maior a TN maior o risco de anomalias cromossômicas e, nos casos com cariótipos normais, maior a freqüência de malformações estruturais, em especial defeitos cardíacos, resultados gestacionais adversos e alterações à avaliação pós-natal / The aim of this study was to evaluate pregnancy and postnatal outcomes in fetuses with increased nuchal translucency thickness (NT). Two hundred seventy five fetuses with increased NT were examined with karyotyping analysys, serial ultrasound scans, ecocardiography and postnatal clinical and genetic evaluation at the Fetal Medicine Unit - Departament of Obstetrics - São Paulo University. The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. At the anomaly scan, 73.1% of the abnormal karyotype and 24.7% of the normal fetuses presented structural abnormalities, one third of these were major malformations with 35.7% of cardiac defects. Adverse pregnancy outcome as miscarriages, intrauterine and neonatal deaths occurred in 76.5% of the abnormal karyotype group and in 10.2% of the normal. 72.7% of the infants with normal karyotype had postnatal examination with 14,8% presenting abnormalities. The chances of having a live and healthy child decreased with increased NT thickness. For NT above 4.5mm this varied from 18.8%, for an unknown karyotype result, to 37.5% for a normal karyotype. The chances of abnormal karyotype increased with NT thickness. In addition, when the karyotype was normal, the frequency of fetal malformations, specially heart defects, adverse pregnancy outcome and postnatal abnormalities increased with NT thickness

Objetivo: analisar o resultado das gestações e pós-natal dos fetos com translucência nucal (TN) aumentada. Método: Duzentos e setenta e cinco fetos com TN aumentada foram avaliados no setor de Medicina Fetal da Clínica Obstétrica do HC-FMUSP, com análise do cariótipo, ultra-sonografia seriada, ecocardiografias fetal e pós-natal e avaliação clinica genética pós-natal. Resultados: 14,2% apresentaram cariótipos alterados e 85,8% normais. A ultra-sonografia morfológica esteve alterada em 73,1% dos casos com cariótipo anormal e em 24,7% dos normais, destes, um terço apresentou malformações estruturais maiores, sendo 35,7% cardíacas. Resultados gestacionais adversos, como abortamento, óbitos intra-útero e neonatal ocorreram em 76,5% dos fetos com anomalias cromossômicas e em 10,2% com cariótipos normais. A avaliação pós-natal foi realizada em 72,7% das crianças, mostrando-se alterada em 14,8% dos casos. A freqüência de criança viva e saudável diminuiu com a medida da TN, que variou de 37,5%, nos casos com cariótipos normais, a 18,8% com cariótipos desconhecidos, quando a TN foi igual ou maior que 4,5 mm. Conclusão: Quanto maior a TN maior o risco de anomalias cromossômicas e, nos casos com cariótipos normais, maior a freqüência de malformações estruturais, em especial defeitos cardíacos, resultados gestacionais adversos e alterações à avaliação pós-natal / The aim of this study was to evaluate pregnancy and postnatal outcomes in fetuses with increased nuchal translucency thickness (NT). Two hundred seventy five fetuses with increased NT were examined with karyotyping analysys, serial ultrasound scans, ecocardiography and postnatal clinical and genetic evaluation at the Fetal Medicine Unit - Departament of Obstetrics - São Paulo University. The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. At the anomaly scan, 73.1% of the abnormal karyotype and 24.7% of the normal fetuses presented structural abnormalities, one third of these were major malformations with 35.7% of cardiac defects. Adverse pregnancy outcome as miscarriages, intrauterine and neonatal deaths occurred in 76.5% of the abnormal karyotype group and in 10.2% of the normal. 72.7% of the infants with normal karyotype had postnatal examination with 14,8% presenting abnormalities. The chances of having a live and healthy child decreased with increased NT thickness. For NT above 4.5mm this varied from 18.8%, for an unknown karyotype result, to 37.5% for a normal karyotype. The chances of abnormal karyotype increased with NT thickness. In addition, when the karyotype was normal, the frequency of fetal malformations, specially heart defects, adverse pregnancy outcome and postnatal abnormalities increased with NT thickness

La présente thèse par articles aborde différentes facettes du dépistage prénatal de certaines aneuploïdies au premier trimestre de la grossesse. L’introduction retrace l’historique du dépistage prénatal et énonce les différents marqueurs biochimiques et échographiques associés aux aneuploïdies. La première publication démontre que le tabagisme maternel abaisse significativement les niveaux sanguins maternels de PAPP-A et de la fraction libre de la β-hCG et augmente significativement la clarté nucale, confirmant la nécessité de contrôler cette co-variable dans le calcul de risque final, du moins pour la trisomie 18. Le deuxième article identifie des seuils de clarté nucale au-delà desquels la biochimie génétique n’apporte aucune valeur additionnelle au dépistage prénatal de la trisomie 21 et de la trisomie 18. Pour les fœtus avec clarté nucale supérieure aux seuils établis, un diagnostic prénatal intrusif devrait être offert sans délai. Le troisième et dernier article porte sur la première détermination des niveaux plasmatiques maternels de la protéine FLRG (follistatin-related gene) au premier trimestre de grossesse et sur son rôle potentiel à titre de marqueur biochimique dans le dépistage prénatal de la trisomie 21. Bien que détectables, les niveaux plasmatiques maternels de FLRG ne sont pas significativement altérés en présence de fœtus avec syndrome de Down. Dans la discussion générale, les trois articles sont abordés sous un angle plus spécifique au Québec. Des données complémentaires et originales y sont présentées. Une discussion sur l’évolution future du dépistage prénatal est entamée et des axes de recherche sont proposés. / In this thesis by articles, we explore different facets of first trimester prenatal screening of aneuploidy. Introduction retraces the origin of prenatal screening and enunciates current biochemical and ultrasound markers associated with aneuploidy. In the first article, impact of maternal smoking on first-trimester prenatal screening results is assessed for Down syndrome and trisomy 18. Both maternal blood levels of PAPP-A and free β-hCG are significantly decreased by maternal smoking while fetal nuchal translucency (NT) thickness is significantly increased. Without adjustment, this results in an increase of false positives, at least for trisomy 18. Based on these results, adjustment for smoking should be mandatory in first-trimester prenatal screening. In the second article, we identify NT threshold values above which biochemical screening provides no additional benefit. In pregnancies in which NT is above the proposed upper cut-offs, invasive prenatal screening should be offered without undue delay. In the third and last article, maternal plasma levels of follistatin- related gene protein (FLRG) are determined for the first time in first trimester of pregnancy. Its potential role as a new marker for Down syndrome is assessed. Although FLRG can be successfully detected in maternal plasma, its levels are not significantly altered by the presence of Down syndrome fetuses. In the general discussion, articles are mainly addressed under a Quebec standpoint. Additional and complementary original data are presented and different clinical research avenues are proposed.

La présente thèse par articles aborde différentes facettes du dépistage prénatal de certaines aneuploïdies au premier trimestre de la grossesse. L’introduction retrace l’historique du dépistage prénatal et énonce les différents marqueurs biochimiques et échographiques associés aux aneuploïdies. La première publication démontre que le tabagisme maternel abaisse significativement les niveaux sanguins maternels de PAPP-A et de la fraction libre de la β-hCG et augmente significativement la clarté nucale, confirmant la nécessité de contrôler cette co-variable dans le calcul de risque final, du moins pour la trisomie 18. Le deuxième article identifie des seuils de clarté nucale au-delà desquels la biochimie génétique n’apporte aucune valeur additionnelle au dépistage prénatal de la trisomie 21 et de la trisomie 18. Pour les fœtus avec clarté nucale supérieure aux seuils établis, un diagnostic prénatal intrusif devrait être offert sans délai. Le troisième et dernier article porte sur la première détermination des niveaux plasmatiques maternels de la protéine FLRG (follistatin-related gene) au premier trimestre de grossesse et sur son rôle potentiel à titre de marqueur biochimique dans le dépistage prénatal de la trisomie 21. Bien que détectables, les niveaux plasmatiques maternels de FLRG ne sont pas significativement altérés en présence de fœtus avec syndrome de Down. Dans la discussion générale, les trois articles sont abordés sous un angle plus spécifique au Québec. Des données complémentaires et originales y sont présentées. Une discussion sur l’évolution future du dépistage prénatal est entamée et des axes de recherche sont proposés. / In this thesis by articles, we explore different facets of first trimester prenatal screening of aneuploidy. Introduction retraces the origin of prenatal screening and enunciates current biochemical and ultrasound markers associated with aneuploidy. In the first article, impact of maternal smoking on first-trimester prenatal screening results is assessed for Down syndrome and trisomy 18. Both maternal blood levels of PAPP-A and free β-hCG are significantly decreased by maternal smoking while fetal nuchal translucency (NT) thickness is significantly increased. Without adjustment, this results in an increase of false positives, at least for trisomy 18. Based on these results, adjustment for smoking should be mandatory in first-trimester prenatal screening. In the second article, we identify NT threshold values above which biochemical screening provides no additional benefit. In pregnancies in which NT is above the proposed upper cut-offs, invasive prenatal screening should be offered without undue delay. In the third and last article, maternal plasma levels of follistatin- related gene protein (FLRG) are determined for the first time in first trimester of pregnancy. Its potential role as a new marker for Down syndrome is assessed. Although FLRG can be successfully detected in maternal plasma, its levels are not significantly altered by the presence of Down syndrome fetuses. In the general discussion, articles are mainly addressed under a Quebec standpoint. Additional and complementary original data are presented and different clinical research avenues are proposed.

Abstract The purpose of this study was to evaluate extended first trimester screening for severe chromosomal disorders and adverse pregnancy outcomes in singleton pregnancies among the general population in Finland. Maternal serum biochemical markers, pregnancy associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotropin (fβ-hCG), and fetal nuchal translucency (NT) thickness were measured during the gestational weeks 8+0–13+6. A computerized risk figure program was used to calculate an individual risk figure for chromosomal disorders. It was investigated whether the screening parameter, PAPP-A, is associated with adverse pregnancy outcomes. The prevalence of Down syndrome (DS) cases in Finland during the years 2002–2006 was 1:364 (N=795). The proportion of women aged 35 years or older increased from 5–10% in the years 1980–1990 to 19.1% during the study period. Most DS cases (61.1%) presented in that age group. The first trimester combined screening for Down syndrome yielded a detection rate (DR) of 81.9% for a 4.3% false positive rate (FPR). The performance was evaluated among 76949 voluntary women during the study period of 01.05.2002–31.12.2008. There were 188 cases of DS. The screening worked better among the older women. The number of invasive procedures needed to detect one case of DS was higher among the younger women. Adding specific algorithms for screening of other chromosomal abnormalities yielded DR of 74.0% for trisomy 18 (T18) and 54.5% for trisomy 13 (T13) with an additional increase of 0.3% FPR. For chromosomal abnormalities other than T18 and T13, the specific algorithms did not improve the screening performance. Low first trimester maternal serum levels of PAPP-A (≤0.30 MoM) were significantly associated with small for gestational age (SGA) newborns and stillbirths (SBs). The combined screening method for DS works well in practice and has been standardized in Finland. In screening for trisomies 18 and 13 a specific algorithm is reasonable. Low first trimester levels of PAPP-A could be used as an independent marker for pregnancies at high risk for SGA babies and SBs. / Tiivistelmä Tutkimuksen tarkoituksena oli arvioida laajennetun ensimmäisen raskauskolmanneksen kromosomipoikkeavuuksien seulonnan toimivuutta yksisikiöisissä raskauksissa suomalaisessa normaaliväestössä. Äidin seerumin biokemialliset merkkiaineet, raskauteen liittyvä valkuaisaine A (PAPP-A) ja raskaushormoni (fβ-hCG) sekä sikiön niskaturvotus mitattiin raskausviikoilla 8+0–13+6. Yksilöllinen riskiluku kromosomipoikkeavuuksille laskettiin käyttäen tietokoneen riskinlaskentaohjelmaa. Seulonnan merkkiaineen, PAPP-A:n, matalien pitoisuuksien yhteyttä epäsuotuisiin raskauden lopputuloksiin tutkittiin. Downin oireyhtymän esiintyvyys Suomessa oli 1:364 (N=795) vuosina 2002–2006. 35-vuotiaiden tai sitä vanhempien naisten osuus oli tutkimusaikana 19.1 %, mikä on huomattavasti suurempi kuin vuosien 1980–1990: 5–10 %. Näiden naisten sikiöiden joukosta löytyi suurin osa Down oireyhtymistä (61.1 %). Ensimmäisen raskauskolmanneksen yhdistelmäseulonnan toimivuutta tutkittiin aikana 01.05.2002–31.12.2008. Tutkimukseen osallistui 76 949 vapaaehtoista naista. Joukossa oli 188 Downin oireyhtymätapausta. Seulonnan herkkyys Downin oireyhtymälle oli 81.9 % ja tarkkuus 4.3 %. Seulonta toimi parhaiten vanhempien naisten joukossa. Niiden kajoavien toimenpiteiden määrä, jotka tarvittiin yhden Down-sikiön löytämiseksi, oli suurempi nuorten naisten joukossa. Tutkimuksessa Downin oireyhtymän algoritmiin lisättiin spesifiset algoritmit trisomioille 18 ja 13, jolloin saavutettiin 74.0 %:n herkkyys trisomialle 18 ja 54.5 %:n herkkyys trisomialle 13. Väärien positiivisten seulontatulosten määrä kasvoi 0.3  %:n verran. Seulonnan toimivuus muiden kromosomipoikkeavuuksien joukossa ei parantunut spesifisten algoritmien avulla. Lisäksi matalan PAPP-A-pitoisuuden yhteys pienipainoisuuten ja kuolleena syntyneisyyteen oli tilastollisesti merkittävä. Tutkimus osoitti, että esimmäisen raskauskolmanneksen yhdistelmäseulonta toimii hyvin käytännössä. Trisomioiden 18 ja 13 seulonnassa spesifisten algoritmien käyttö on järkevää. Matalaa ensimmäisen raskauskolmanneksen PAPP-A-arvoa voitaisiin käyttää itsenäisenä riskimerkkiaineena raskauksille, joissa pienipainoisuuden ja kuolleena syntymisen riski on kohonnut.