Auditory - Visual Matching in Learning Disabilities : Intervention Studies from Finland and Sweden

The present thesis discusses relevant issues in education: 1) learning disabilities including the role of comorbidity in LDs, and 2) the use of research-based interventions. This thesis consists of a series of four studies (three articles), which deepens the knowledge of the field of special education. Intervention studies (N=242) aimed to examine whether training using a nonverbal auditory-visual matching computer program had a remedial effect in different learning disabilities, such as developmental dyslexia, Attention Deficit Disorder (ADD) and Specific Language Impairment (SLI). These studies were conducted in both Finland and Sweden. The intervention’s non-verbal character made an international perspective possible. The results of the intervention studies confirmed, that the auditory-visual matching computer program, called Audilex had positive intervention effects. In Study I of children with developmental dyslexia there were also improvements in reading skills, specifically in reading nonsense words and reading speed. These improvements in tasks, which are thought to rely on phonological processing, suggest that such reading difficulties in dyslexia may stem in part from more basic perceptual difficulties, including those required to manage the visual and auditory components of the decoding task. In Study II the intervention had a positive effect on children with dyslexia; older students with dyslexia and surprisingly, students with ADD also benefited from this intervention. In conclusion, the role of comorbidity was apparent. An intervention effect was evident also in students’ school behavior. Study III showed that children with SLI experience difficulties very similar to those of children with dyslexia in auditory-visual matching. Children with language-based learning disabilities, such as dyslexia and SLI benefited from the auditory-visual matching intervention. Also comorbidity was evident among these children; in addition to formal diagnoses, comorbidity was explored with an assessment inventory, which was developed for this thesis. Interestingly, an overview of the data of this thesis shows positive intervention effects in all studies despite learning disability, language, gender or age. These findings have been described by a concept inter-modal transpose. Self-evidently these issues need further studies. In learning disabilities the aim in the future will also be to identify individuals at risk rather than by deficit; this aim can be achieved by using research-based interventions, intensified support in general education and inclusive special education. Keywords: learning disabilities, developmental dyslexia, attention deficit disorder, specific language impairment, language-based learning disabilities, comorbidity, auditory-visual matching, research-based interventions, inter-modal transpose

The DISC1 Pathway in the Genetic Etiology of Schizophrenia

Schizophrenia is a severe psychotic disorder affecting 0.5-1 % of the population. The disorder is characterized by hallucinations; delusions; disorganized behavior and speech; avolition; anhedonia; flattened affect and cognitive deficits. The etiology of the disorder is complex with evidence for multiple genes contributing to the onset of the disorder along with environmental factors. DISC1 is one of the most promising candidate genes for schizophrenia. It codes for a protein which takes part in numerous molecular interactions along several pathways. This network, termed as the DISC1 pathway, is evidently important for the development and maturation of the central nervous system from the embryo until young adulthood. Disruption at these pathways is thought to predispose schizophrenia. In the present study, we have studied the DISC1 pathway in the etiology of schizophrenia in the Finnish population. We have utilized large Finnish samples; the schizophrenia family sample where DISC1 was originally shown to associate with schizophrenia and the Northern Finland birth cohort 1966 (NFBC66). Several DISC1 binding partners displayed evidence for association in the family sample along with DISC1. Through a genome-wide linkage study, we found a significant linkage signal to a locus where a DISC1 binding partner NDE1 is located at the carriers of a certain DISC1 risk variant. In a follow-up study, genetic markers in NDE1 displayed significant evidence for association with schizophrenia. Further exploration of association between 11 genes of the DISC1 pathway and schizophrenia led to recognition of novel variants in NDEL1, PDE4B and PDE4D that significantly either increased or decreased the risk for schizophrenia. Further, we found evidence that DISC1 itself has a significant role in the human mental functioning even in the healthy population. Variants in DISC1 had a significant effect on anhedonia which is a trait present at everybody but is in its severe form one of the main symptoms of schizophrenia and correlates with the risk of developing the disorder. Further, utilizing genome-wide marker data, we recognized three genes; MIR620; CCDC141 and LCT; that are closely related to the DISC1 pathway but which effects on anhedonia were observable only at the individuals who carried these specific DISC1 variants. Our findings significantly add up to the previous evidence for the involvement of DISC1 and the DISC1 pathway in the etiology of schizophrenia and psychosis. Our results support the concept of a number of DISC1 pathway related genes contributing in the etiology of schizophrenia along with DISC1 and provide new candidates for the studies of schizophrenia. Our findings also significantly increase the importance of DISC1 itself as having a role in psychological functioning in the general population.

Elimination of axial venous reflux

Chronic venous disease (CVD), including uncomplicated varicose veins and chronic venous insufficiency, is one of the most common medical conditions in the Western world. The central feature of CVD is venous reflux, which may be primary, congenital, or result from an antecedent event, usually an acute deep venous thrombosis (DVT). When the history of DVT is clear, the clinical manifestations of secondary CVD are commonly referred to as the post-thrombotic syndrome. Regardless of the underlying etiology, the final pathway leading to symptoms is ambulatory venous hypertension. The spectrum of symptoms and signs of CVD ranges from minor cosmetic problems to venous ulceration, which results in considerable morbidity and increased medical costs. Aims of this study were to evaluate the outcome of superficial venous surgery performed with or without preoperative duplex evaluation and venous marking with hand-held doppler, to assess short-term outcome of ultrasound-guided foam sclerotherapy in patients with axial superficial venous incompetence, as well as to compare reflux patterns after catheter-directed and systemic thrombolysis of deep ileofemoral venous thrombosis, and to evaluate the long-term outcome of deep venous reconstructions for severe chronic venous insufficiency. The study consists of five separate retrospective projects and includes 315 patients. Of this, 133 patients had undergone superficial venous surgery 2 to 5 years earlier according to preoperative duplex examination and venous marking, or according to clinical evaluation alone, or to a written plan without venous marking. A total of 112 patients had undergone ultrasound-guided foam sclerotherapy 5.5 to 16.5 months before. In addition, 32 patients had received either catheter-directed or systemic thrombolysis for DVT 2 to 3 years earlier, and 38 patients had undergone deep venous reconstructions 2 to 7 years earlier. In the present studies, some venous reflux was present postoperatively irrespective of the method of evaluation or ablation of the reflux. It seemed, however, that preoperative examination with duplex ultrasound and marking of reflux sites before the operation by the operating surgeon improves the outcome of superficial venous surgery. Ultrasound-guided foam sclerotherapy is effective in elimination of venous reflux in selected cases in short-term follow-up. Catheter-directed thrombolysis for deep iliofemoral venous thrombosis reduces later reflux and most probably the development of post-thrombotic syndrome as well. The outcome of deep venous reconstructions, especially for post-thrombotic deep venous incompetence, is poor. Thus, prevention of valvular damage by active treatment of deep venous thrombosis is important.

Common and rare variants of the renin-angiotensin system and their relation to antihypertensive drug responses

Most of the diseases affecting public health, like hypertension, are multifactorial by etiology. Hypertension is influenced by genetic, life style and environmental factors. Estimation of the influence of genes to the risk of essential hypertension varies from 30 to 50%. It is plausible that in most of the cases susceptibility to hypertension is determined by the action of more than one gene. Although the exact molecular mechanism underlying essential hypertension remains obscure, several monogenic forms of hypertension have been identified. Since common genetic variations may predict, not only to susceptibility to hypertension, but also response to antihypertensive drug therapy, pharmacogenetic approaches may provide useful markers in finding relations between candidate genes and phenotypes of hypertension. The aim of this study was to identify genetic mutations and polymorphisms contributing to human hypertension, and examine their relationships to intermediate phenotypes of hypertension, such as blood pressure (BP) responses to antihypertensive drugs or biochemical laboratory values. Two groups of patients were investigated in the present study. The first group was collected from the database of patients investigated in the Hypertension Outpatient Ward, Helsinki University Central Hospital, and consisted of 399 subjects considered to have essential hypertension. Frequncies of the mutant or variant alleles were compared with those in two reference groups, healthy blood donors (n = 301) and normotensive males (n = 175). The second group of subjects with hypertension was collected prospectively. The study subjects (n=313) underwent a protocol lasting eight months, including four one-month drug treatment periods with antihypertensive medications (thiazide diuretic, β-blocker, calcium channel antagonist, and an angiotensin II receptor antagonist). BP responses and laboratory values were related to polymorphims of several candidate genes of the renin-angiotensin system (RAS). In addition, two patients with typical features of Liddle’s syndrome were screened for mutations in kidney epithelial sodium channel (ENaC) subunits. Two novel mutations causing Liddle’s syndrome were identified. The first mutation identified located in the beta-subunit of ENaC and the second mutation found located in the gamma-subunit, constituting the first identified Liddle mutation locating in the extracellular domain. This mutation showed 2-fold increase in channel activity in vitro. Three gene variants, of which two are novel, were identified in ENaC subunits. The prevalence of the variants was three times higher in hypertensive patients (9%) than in reference groups (3%). The variant carriers had increased daily urinary potassium excretion rate in relation to their renin levels compared with controls suggesting increased ENaC activity, although in vitro they did not show increased channel activity. Of the common polymorphisms of the RAS studied, angiotensin II receptor type I (AGTR1) 1166 A/C polymorphism was associated with modest changes in RAS activity. Thus, patients homozygous for the C allele tended to have increased aldosterone and decreased renin levels. In vitro functional studies using transfected HEK293 cells provided additional evidence that the AGTR1 1166 C allele may be associated with increased expression of the AGTR1. Common polymorphisms of the alpha-adducin and the RAS genes did not significantly predict BP responses to one-month monotherapies with hydroclorothiazide, bisoprolol, amlodipin, or losartan. In conclusion, two novel mutations of ENaC subunits causing Liddle’s syndrome were identified. In addition, three common ENaC polymorphisms were shown to be associated with occurrence of essential hypertension, but their exact functional and clinical consequences remain to be explored. The AGTR1 1166 C allele may modify the endocrine phenotype of hypertensive patients, when present in homozygous form. Certain widely studied polymorphisms of the ACE, angiotensinogen, AGTR1 and alpha-adducin genes did not significantly affect responses to a thiazide, β-blocker, calcium channel antagonist, and angiotensin II receptor antagonist.

Paradigms in Statistical Inference for Finite Populations; Up to the 1950s

Modern sample surveys started to spread after statistician at the U.S. Bureau of the Census in the 1940s had developed a sampling design for the Current Population Survey (CPS). A significant factor was also that digital computers became available for statisticians. In the beginning of 1950s, the theory was documented in textbooks on survey sampling. This thesis is about the development of the statistical inference for sample surveys. For the first time the idea of statistical inference was enunciated by a French scientist, P. S. Laplace. In 1781, he published a plan for a partial investigation in which he determined the sample size needed to reach the desired accuracy in estimation. The plan was based on Laplace s Principle of Inverse Probability and on his derivation of the Central Limit Theorem. They were published in a memoir in 1774 which is one of the origins of statistical inference. Laplace s inference model was based on Bernoulli trials and binominal probabilities. He assumed that populations were changing constantly. It was depicted by assuming a priori distributions for parameters. Laplace s inference model dominated statistical thinking for a century. Sample selection in Laplace s investigations was purposive. In 1894 in the International Statistical Institute meeting, Norwegian Anders Kiaer presented the idea of the Representative Method to draw samples. Its idea was that the sample would be a miniature of the population. It is still prevailing. The virtues of random sampling were known but practical problems of sample selection and data collection hindered its use. Arhtur Bowley realized the potentials of Kiaer s method and in the beginning of the 20th century carried out several surveys in the UK. He also developed the theory of statistical inference for finite populations. It was based on Laplace s inference model. R. A. Fisher contributions in the 1920 s constitute a watershed in the statistical science He revolutionized the theory of statistics. In addition, he introduced a new statistical inference model which is still the prevailing paradigm. The essential idea is to draw repeatedly samples from the same population and the assumption that population parameters are constants. Fisher s theory did not include a priori probabilities. Jerzy Neyman adopted Fisher s inference model and applied it to finite populations with the difference that Neyman s inference model does not include any assumptions of the distributions of the study variables. Applying Fisher s fiducial argument he developed the theory for confidence intervals. Neyman s last contribution to survey sampling presented a theory for double sampling. This gave the central idea for statisticians at the U.S. Census Bureau to develop the complex survey design for the CPS. Important criterion was to have a method in which the costs of data collection were acceptable, and which provided approximately equal interviewer workloads, besides sufficient accuracy in estimation.

Simulation and graph mining tools for improving gene mapping efficiency

Gene mapping is a systematic search for genes that affect observable characteristics of an organism. In this thesis we offer computational tools to improve the efficiency of (disease) gene-mapping efforts. In the first part of the thesis we propose an efficient simulation procedure for generating realistic genetical data from isolated populations. Simulated data is useful for evaluating hypothesised gene-mapping study designs and computational analysis tools. As an example of such evaluation, we demonstrate how a population-based study design can be a powerful alternative to traditional family-based designs in association-based gene-mapping projects. In the second part of the thesis we consider a prioritisation of a (typically large) set of putative disease-associated genes acquired from an initial gene-mapping analysis. Prioritisation is necessary to be able to focus on the most promising candidates. We show how to harness the current biomedical knowledge for the prioritisation task by integrating various publicly available biological databases into a weighted biological graph. We then demonstrate how to find and evaluate connections between entities, such as genes and diseases, from this unified schema by graph mining techniques. Finally, in the last part of the thesis, we define the concept of reliable subgraph and the corresponding subgraph extraction problem. Reliable subgraphs concisely describe strong and independent connections between two given vertices in a random graph, and hence they are especially useful for visualising such connections. We propose novel algorithms for extracting reliable subgraphs from large random graphs. The efficiency and scalability of the proposed graph mining methods are backed by extensive experiments on real data. While our application focus is in genetics, the concepts and algorithms can be applied to other domains as well. We demonstrate this generality by considering coauthor graphs in addition to biological graphs in the experiments.

Teachers' attitudes to and beliefs about web-based Collaborative Learning Environments in the context of an international implementation

"Fifty-six teachers, from four European countries, were interviewed to ascertain their attitudes to and beliefs about the Collaborative Learning Environments (CLEs) which were designed under the Innovative Technologies for Collaborative Learning Project. Their responses were analysed using categories based on a model from cultural-historical activity theory [Engestrom, Y. (1987). Learning by expanding.- An activity-theoretical approach to developmental research. Helsinki: Orienta-Konsultit; Engestrom, Y., Engestrom, R., & Suntio, A. (2002). Can a school community learn to master its own future? An activity-theoretical study of expansive learning among middle school teachers. In G. Wells & G. Claxton (Eds.), Learning for life in the 21st century. Oxford: Blackwell Publishers]. The teachers were positive about CLEs and their possible role in initiating pedagogical innovation and enhancing personal professional development. This positive perception held across cultures and national boundaries. Teachers were aware of the fact that demanding planning was needed for successful implementations of CLEs. However, the specific strategies through which the teachers can guide students' inquiries in CLEs and the assessment of new competencies that may characterize student performance in the CLEs were poorly represented in the teachers' reflections on CLEs. The attitudes and beliefs of the teachers from separate countries had many similarities, but there were also some clear differences, which are discussed in the article. (c) 2005 Elsevier Ltd. All rights reserved."

Misalignment as a Therapeutic Resource

The article reports conversation analysis of a single cognitive psychotherapy session in which an interactional misalignment between the therapist and the patient emerges, culminates, and is mitigated. Through this case study, the interactional practices lead- ing to a rupture in therapeutic alliance and the practices leading to its mending are explored. In the session the therapist pursues investigative orientation in relation to the patient’s experience under discussion, whereas the patient maintains orientation to “troubles-telling.” The diverging projects of the participants amount to overt misalign- ment. Eventually, the therapist brings the relationship of the patient and herself as a topic of conversation in ways which turn the misalignment into a resource of therapeu- tic work. The microanalysis of actual interactional patterns in this single case is linked to discussions of therapeutic alliance in psychotherapeutic literature.