Kirja-arvostelu

Kirjallisuusarvostelu

Spontaneous Focusing on Numerosity in the Development of Early Mathematical Skills

The aim of the present set of longitudinal studies was to explore 3-7-year-old children.s Spontaneous FOcusing on Numerosity (SFON) and its relation to early mathematical development. The specific goals were to capture in method and theory the distinct process by which children focus on numerosity as a part of their activities involving exact number recognition, and individual differences in this process that may be informative in the development of more complex number skills. Over the course of conducting the five studies, fifteen novel tasks were progressively developed for the SFON assessments. In the tasks, confounding effects of insufficient number recognition, verbal comprehension, other procedural skills as well as working memory capacity were aimed to be controlled. Furthermore, how children.s individual differences in SFON are related to their development of number sequence, subitizing-based enumeration, object counting and basic arithmetic skills was explored. The effect of social interaction on SFON was tested. Study I captured the first phase of the 3-year longitudinal study with 39 children. It was investigated whether there were differences in 3-year-old children.s tendency to focus on numerosity, and whether these differences were related to the children.s development of cardinality recognition skills from the age of 3 to 4 years. It was found that the two groups of children formed on the basis of their amount of SFON tendency at the age of 3 years differed in their development of recognising and producing small numbers. The children whose SFON tendency was very predominant developed faster in cardinality related skills from the age of 3 to 4 years than the children whose SFON tendency was not as predominant. Thus, children.s development in cardinality recognition skills is related to their SFON tendency. Studies II and III were conducted to investigate, firstly, children.s individual differences in SFON, and, secondly, whether children.s SFON is related to their counting development. Altogether nine tasks were designed for the assessments of spontaneous and guided focusing on numerosity. The longitudinal data of 39 children in Study II from the age of 3.5 to 6 years showed individual differences in SFON at the ages of 4, 5 and 6 years, as well as stability in children.s SFON across tasks used at different ages. The counting skills were assessed at the ages of 3.5, 5 and 6 years. Path analyses indicated a reciprocal tendency in the relationship between SFON and counting development. In Study III, these results on the individual differences in SFON tendency, the stability of SFON across different tasks and the relationship of SFON and mathematical skills were confirmed by a larger-scale cross-sectional study of 183 on average 6.5-year-old children (range 6;0-7;0 years). The significant amount of unique variance that SFON accounted for number sequence elaboration, object counting and basic arithmetic skills stayed statistically significant (partial correlations varying from .27 to .37) when the effects of non-verbal IQ and verbal comprehension were controlled. In addition, to confirm that the SFON tasks assess SFON tendency independently from enumeration skills, guided focusing tasks were used for children who had failed in SFON tasks. It was explored whether these children were able to proceed in similar tasks to SFON tasks once they were guided to focus on number. The results showed that these children.s poor performance in the SFON tasks was not caused by their deficiency in executing the tasks but on lacking focusing on numerosity. The longitudinal Study IV of 39 children aimed at increasing the knowledge of associations between children.s long-term SFON tendency, subitizing-based enumeration and verbal counting skills. Children were tested twice at the age of 4-5 years on their SFON, and once at the age of 5 on their subitizing-based enumeration, number sequence production, as well as on their skills for counting of objects. Results showed considerable stability in SFON tendency measured at different ages, and that there is a positive direct association between SFON and number sequence production. The association between SFON and object counting skills was significantly mediated by subitizing-based enumeration. These results indicate that the associations between the child.s SFON and sub-skills of verbal counting may differ on the basis of how significant a role understanding the cardinal meanings of number words plays in learning these skills. The specific goal of Study V was to investigate whether it is possible to enhance 3-year old children.s SFON tendency, and thus start children.s deliberate practice in early mathematical skills. Participants were 3-year-old children in Finnish day care. The SFON scores and cardinality-related skills of the experimental group of 17 children were compared to the corresponding results of the 17 children in the control group. The results show an experimental effect on SFON tendency and subsequent development in cardinality-related skills during the 6-month period from pretest to delayed posttest in the children with some initial SFON tendency in the experimental group. Social interaction has an effect on children.s SFON tendency. The results of the five studies assert that within a child.s existing mathematical competence, it is possible to distinguish a separate process, which refers to the child.s tendency to spontaneously focus on numerosity. Moreover, there are significant individual differences in children.s SFON at the age of 3-7 years. Moderate stability was found in this tendency across different tasks assessed both at the same and at different ages. Furthermore, SFON tendency is related to the development of early mathematical skills. Educational implications of the findings emphasise, first, the importance of regarding focusing on numerosity as a separate, essential process in the assessments of young children.s mathematical skills. Second, the substantial individual differences in SFON tendency during the childhood years suggest that uncovering and modeling this kind of mathematically meaningful perceiving of the surroundings and tasks could be an efficient tool for promoting young children.s mathematical development, and thus prevent later failures in learning mathematical skills. It is proposed to consider focusing on numerosity as one potential sub-process of activities involving exact number recognition in future studies.

Virus Infections in Early Childhood, Cow’s Milk Formula Exposure and Genetic Predisposition in the Development of Diabetes-Associated Autoimmunity

Varhaislapsuuden virusinfektioiden, lehmänmaitopohjaisen äidinmaitovastikeen ja geneettisen alttiuden merkitys diabetekseen liittyvän autoimmuniteetin kehittymisessä Tyypin 1 diabetes on autoimmuunisairaus, joka syntyy haiman insuliinia tuottavien beta-solujen tuhouduttua elimistön oman immuunipuolustusjärjestelmän hyökkäyksen seurauksena. Sekä perimän että ympäristötekijöiden arvellaan vaikuttavan tautiprosessiin, mutta taudin tarkkaa syntymekanismia ei tunneta. Tutkimuksen tarkoituksena oli selvittää varhaislapsuuden ympäristötekijöiden vaikutusta beta-soluautoimmuniteetin syntyyn, erityispaino tutkimuksessa oli ympäristötekijöiden yhteisvaikutuksessa sekä geneettisten riskitekijöiden ja ympäristötekijöiden vuorovaikutuksessa. Varhaislapsuudessa sairastettu sytomegalovirus- tai enterovirusinfektio ei lisännyt beta-soluautoimmuniteetin riskiä lapsilla, joilla on geneettisesti kohonnut riski sairastua tyypin 1 diabetekseen. Ennen puolen vuoden ikää sairastettu rotavirusinfektio lisäsi hieman tyypin 1 diabetekseen liittyvän autoimmuniteetin riskiä. Tarkemmassa analyysissa varhaislapsuuden enterovirusinfektio osoittautui kuitenkin autovasta-aineiden muodostumisen riskitekijäksi niiden lasten joukossa, jotka olivat saaneet lehmänmaitopohjaista äidinmaidon vastiketta ensimmäisten elinkuukausien aikana. Tämä löydös viittaa enterovirusinfektion ja lehmänmaitopohjaisen vastikkeen yhteisvaikutukseen tyypin 1 diabetekseen liittyvän autoimmuniteetin synnyssä. Löydösten mukaan PTPN22 geenin C1858T polymorfismi vaikuttaa CD4+ T solujen aktivaatioon ja proliferaatiovasteeseen, 1858T alleeliin liittyy alentunut T-soluresepto-rivälitteinen aktivaatio. 1858T alleelin kantajuuteen liittyy lisäksi lisääntynyt autovasta-aineiden ja kliinisen diabeteksen ilmaantuvuus. Tämä yhteys rajoittui yksilöihin, jotka olivat altistuneet lehmänmaitopohjaiselle vastikkeelle ennen kuuden kuukauden ikää. Tulosten mukaan sekä ympäristötekijöiden väliset yhteisvaikutukset että perimä vaikuttavat yksittäisen ympäristötekijän merkitykseen tyypin 1 diabetekseen liittyvän autoimmuniteetin synnyssä. Nämä yhteisvaikutukset ympäristötekijöiden kesken ja perimän ja ympäristötekijöiden välillä selittävät aiemmin julkaistujen tulosten ristiriittaisuutta tutkimuksissa, joissa on analysoitu vain yhden ympäristötekijän vaikutusta diabeteksen ilmaantuvuuteen.

Markers of Bone Turnover In Preclinical Development of Drugs for Skeletal Diseases

Skeletal tissue is constantly remodeled in a process where osteoclasts resorb old bone and osteoblasts form new bone. Balance in bone remodeling is related to age, gender and genetic factors, but also many skeletal diseases, such as osteoporosis and cancer-induced bone metastasis, cause imbalance in bone turnover and lead to decreased bone mass and increased fracture risk. Biochemical markers of bone turnover are surrogates for bone metabolism and may be used as indicators of the balance between bone resorption and formation. They are released during the remodeling process and can be conveniently and reliably measured from blood or urine by immunoassays. Most commonly used bone formation markers include N-terminal propeptides of type I collagen (PINP) and osteocalcin, whereas tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) and C-terminal cross-linked telopeptide of type I collagen (CTX) are common resorption markers. Of these, PINP has been, until recently, the only marker not commercially available for preclinical use. To date, widespread use of bone markers is still limited due to their unclear biological significance, variability, and insufficient evidence of their prognostic value to reflect long term changes. In this study, the feasibility of bone markers as predictors of drug efficacy in preclinical osteoporosis models was elucidated. A non-radioactive PINP immunoassay for preclinical use was characterized and validated. The levels of PINP, N-terminal mid-fragment of osteocalcin, TRACP 5b and CTX were studied in preclinical osteoporosis models and the results were compared with the results obtained by traditional analysis methods such as histology, densitometry and microscopy. Changes in all bone markers at early timepoints correlated strongly with the changes observed in bone mass and bone quality parameters at the end of the study. TRACP 5b correlated strongly with the osteoclast number and CTX correlated with the osteoclast activity in both in vitro and in vivo studies. The concept “resorption index” was applied to the relation of CTX/TRACP 5b to describe the mean osteoclast activity. The index showed more substantial changes than either of the markers alone in the preclinical osteoporosis models used in this study. PINP was strongly associated with bone formation whereas osteocalcin was associated with both bone formation and resorption. These results provide novel insight into the feasibility of PINP, osteocalcin, TRACP 5b and CTX as predictors of drug efficacy in preclinical osteoporosis models. The results support clinical findings which indicate that short-term changes of these markers reflect long-term responses in bone mass and quality. Furthermore, this information may be useful when considering cost-efficient and clinically predictive drug screening and development assays for mining new drug candidates for skeletal diseases.

Importance of considering food waste in the development of sustainable food packaging systems

Meeting the needs of both present and future generations forms the foundation of sustainable development. Concern about food demand is increasing alongside the continuously growing population. In the pursuit of food security preventing food waste is one solution avoiding the negative environmental impacts that result from producing food unnecessarily. Packages offer one answer to preventing food waste, as they 1) preserve and protect food, 2) introduce the user to the correct way to handle and use the food and package and 3) allow the user to consume the food in its entirety. This thesis aims to enhance the sustainability of food packages by giving special emphasis to preventing food waste. The focus of this thesis is to assist the packaging designer in being able to take into account the requirements for the sustainability of food packages and to be able to integrate these requirements into the product development process. In addition, life cycle methods that can be used as a tool in the packaging design process or in assessing the sustainability of finished food-packaging combinations are evaluated. The methods of life cycle costing (LCC) and life cycle working environment (LCWE) are briefly discussed. The method of life cycle assessment (LCA) is examined more thoroughly through the lens of the literature review of food-package LCA case studies published in the 21st century in three relevant journals. Based on this review and on experiences learned from conducting LCAs, recommendations are given as to how the LCA practitioner should conduct a food packaging study to make most of the results. Two case studies are presented in this thesis. The first case study relates the results of a life cycle assessment conducted for three food items (cold cut (ham), sliced dark bread (rye) and Soygurt drink) and the alternative packaging options of each. Results of this study show that the packaging constitutes only 1–12 % of the total environmental impacts of the food-packaging combination. The greatest effect is derived from the food itself and the wasted food. Even just a small percentage of wasted food causes more environmental impacts than does the packaging. The second case study presents the results of LCC and LCWE analysis done for fruit and vegetable transport packages. In this thesis, the specific results of the study itself are not the focus, but rather the study methods and scope are analysed based on how these complement the sustainability assessment of food packages. This thesis presents reasons why prevention of food waste should be more thoroughly taken into account in food packaging design. In addition, the task of the packaging designer is facilitated by the requirements of sustainable food packaging, by the methods and step-by-step guidance on how to integrate sustainability issues into the design process, and by the recommendations on how to assess the sustainability of food packages. The intention of this thesis is to express the issues that are important in the field of the food packaging industry. Having recognised and implemented these issues, businesses can better manage the risks that could follow from neglecting these sustainability aspects.

Cost-benefit analysis of using test automation in the development of embedded software

The goal of this thesis is to make a case study of test automation’s profitability in the development of embedded software in a real industrial setting. The cost-benefit analysis is done by considering the costs and benefits test automation causes to software development, before the software is released to customers. The potential benefits of test automation regarding software quality after customer release were not estimated. Test automation is a significant investment which often requires dedicated resources. When done accordingly, the investment in test automation can produce major cost savings by reducing the need for manual testing effort, especially if the software is developed with an agile development framework. It can reduce the cost of avoidable rework of software development, as test automation enables the detection of construction time defects in the earliest possible moment. Test automation also has many pitfalls such as test maintainability and testability of the software, and if those areas are neglected, the investment in test automation may become worthless or it may even produce negative results. The results of this thesis suggest that test automation is very profitable at the company under study.

Development of beam and plate finite elements based on the absolute nodal coordinate formulation

The focus of this dissertation is to develop finite elements based on the absolute nodal coordinate formulation. The absolute nodal coordinate formulation is a nonlinear finite element formulation, which is introduced for special requirements in the field of flexible multibody dynamics. In this formulation, a special definition for the rotation of elements is employed to ensure the formulation will not suffer from singularities due to large rotations. The absolute nodal coordinate formulation can be used for analyzing the dynamics of beam, plate and shell type structures. The improvements of the formulation are mainly concentrated towards the description of transverse shear deformation. Additionally, the formulation is verified by using conventional iso-parametric solid finite element and geometrically exact beam theory. Previous claims about especially high eigenfrequencies are studied by introducing beam elements based on the absolute nodal coordinate formulation in the framework of the large rotation vector approach. Additionally, the same high eigenfrequency problem is studied by using constraints for transverse deformation. It was determined that the improvements for shear deformation in the transverse direction lead to clear improvements in computational efficiency. This was especially true when comparative stress must be defined, for example when using elasto-plastic material. Furthermore, the developed plate element can be used to avoid certain numerical problems, such as shear and curvature lockings. In addition, it was shown that when compared to conventional solid elements, or elements based on nonlinear beam theory, elements based on the absolute nodal coordinate formulation do not lead to an especially stiff system for the equations of motion.

Identification of extractives and polysaccharides as foulants in membrane filtration of pulp and paper mill effluents

The search for new renewable materials has intensified in recent years. Pulp and paper mill process streams contain a number of potential compounds which could be used in biofuel production and as raw materials in the chemical, food and pharmaceutical industries. Prior to utilization, these compounds require separation from other compounds present in the process stream. One feasible separation technique is membrane filtration but to some extent, fouling still limits its implementation in pulp and paper mill applications. To mitigate fouling and its effects, foulants and their fouling mechanisms need to be well understood. This thesis evaluates fouling in filtration of pulp and paper mill process streams by means of polysaccharide model substance filtrations and by development of a procedure to analyze and identify potential foulants, i.e. wood extractives and carbohydrates, from fouled membranes. The model solution filtration results demonstrate that each polysaccharide has its own fouling mechanism, which also depends on the membrane characteristics. Polysaccharides may foul the membranes by adsorption and/or by gel/cake layer formation on the membrane surface. Moreover, the polysaccharides interact, which makes fouling evaluation of certain compound groups very challenging. Novel methods to identify wood extractive and polysaccharide foulants are developed in this thesis. The results show that it is possible to extract and identify wood extractives from membranes fouled in filtration of pulp and paper millstreams. The most effective solvent was found to be acetone:water (9:1 v/v) because it extracted both lipophilic extractives and lignans at high amounts from the fouled membranes and it was also non-destructive for the membrane materials. One hour of extraction was enough to extract wood extractives at high amounts for membrane samples with an area of 0.008 m2. If only qualitative knowledge of wood extractives is needed a simplified extraction procedure can be used. Adsorption was the main fouling mechanism in extractives-induced fouling and dissolved fatty and resin acids were mostly the reason for the fouling; colloidal fouling was negligible. Both process water and membrane characteristics affected extractives-induced fouling. In general, the more hydrophilic regenerated cellulose (RC) membrane fouled less that the more hydrophobic polyethersulfone (PES) and polyamide (PA) membranes independent of the process water used. Monosaccharide and uronic acid units could also be identified from the fouled synthetic polymeric membranes. It was impossible to analyze all monosaccharide units from the RC membrane because the analysis result obtained contained degraded membrane material. One of the fouling mechanisms of carbohydrates was adsorption. Carbohydrates were not potential adsorptive foulants to the sameextent as wood extractives because their amount in the fouled membranes was found to be significantly lower than the amount of wood extractives.

Local Binary Patterns in Focal-Plane Processing. Analysis and Applications

Feature extraction is the part of pattern recognition, where the sensor data is transformed into a more suitable form for the machine to interpret. The purpose of this step is also to reduce the amount of information passed to the next stages of the system, and to preserve the essential information in the view of discriminating the data into different classes. For instance, in the case of image analysis the actual image intensities are vulnerable to various environmental effects, such as lighting changes and the feature extraction can be used as means for detecting features, which are invariant to certain types of illumination changes. Finally, classification tries to make decisions based on the previously transformed data. The main focus of this thesis is on developing new methods for the embedded feature extraction based on local non-parametric image descriptors. Also, feature analysis is carried out for the selected image features. Low-level Local Binary Pattern (LBP) based features are in a main role in the analysis. In the embedded domain, the pattern recognition system must usually meet strict performance constraints, such as high speed, compact size and low power consumption. The characteristics of the final system can be seen as a trade-off between these metrics, which is largely affected by the decisions made during the implementation phase. The implementation alternatives of the LBP based feature extraction are explored in the embedded domain in the context of focal-plane vision processors. In particular, the thesis demonstrates the LBP extraction with MIPA4k massively parallel focal-plane processor IC. Also higher level processing is incorporated to this framework, by means of a framework for implementing a single chip face recognition system. Furthermore, a new method for determining optical flow based on LBPs, designed in particular to the embedded domain is presented. Inspired by some of the principles observed through the feature analysis of the Local Binary Patterns, an extension to the well known non-parametric rank transform is proposed, and its performance is evaluated in face recognition experiments with a standard dataset. Finally, an a priori model where the LBPs are seen as combinations of n-tuples is also presented

Development of support and drive systems for defiberization drum

Diplomityön tarkoituksena oli kuidutusrumpulaitteiston käytön- ja kannatuksen kehittä-minen. Työ rajattiin laajuutensa vuoksi koskemaan tuotesarjan viittä pienintä kokoa. Työn alkuosassa käsitellään kuidutuksen teoriaa ja siihen soveltuvia laitteistoja. Käytön suunnittelun kannalta olennaista käynnistystehon tarvetta on tarkasteltu lähtökohdaisesti fysiikan avulla. Perustietoja teorialle on haettu aiemmista tutkimuksista sekä kirjallisuu-desta. Tarkastelun tuloksena teoriaa on kehitty ja se on saatu vastaamaan todellisuutta aiempaa paremmin. Kannatuksen ja käytön toteuttamisvaihtoja etsittäessä on käytetty systemaattisen koneen-suunnittelun keinoja. Saatuja ideoita on arvioitu teknillis-taloudellisin perustein ja näistä on valittu parhaat vaihtoehdot jatkokehitykseen. Jatkokehitysvaiheessa ratkaisuvaihto-ehtoja on tarkasteltu komponenttitasolla ja näistä on tehty yksityiskohtaiset kustannus-laskelmat. Työn tuloksena on esitetty kannatuksen ja käytön toteutusvaihtoehto, jonka avulla voidaan saavuttaa merkittäviä kustannussäästöjä. Korkea, 30 prosentin kustannussäästö-tavoite saavutettiin.

Refleksiivistä oppihistorian tarkastelua Tartossa : Reflecting on Knowledge Production : The Development of Folkloristics and Ethnology, 17.-19.5.2007 Tartto

Ajankohtaista

Regenerated cellulose ultrafiltration membranes in the treatment of pulp and paper mill process waters

Ultrafiltration (UF) is widely applied in different separation processes in the pulp and paper industry. The growing need to protect the environment, a lack of pure water and an interest in producing high-value chemicals from compounds present in process waters will probably lead to an increase in the use of UF in the pulp and paper industry. The efficiency and cost-effectiveness of a UF process depends on the applied membrane. The membrane should have a high and stable filtration capacity, a particular selectivity and a long operational lifetime. To meet these requirements a membrane should have a low fouling tendency. In addition, it should withstand the prevailing operational and chemical conditions. This thesis evaluates the performance and applicability of the regenerated cellulose (RC) membranes 00030T and C2 in the treatment of pulp and paper mill process waters based on the requirements above. The results demonstrated that both the tested RC membranes fulfilled well the requirement of high filtration capacity. In addition, in the filtration of a paper mill clear filtrate (CF) the RC membranes were not as greatly affected by variations in the CF quality as a polysulphone membrane. Furthermore, due to their extreme hydrophilicity and weak charge the fouling tendency of the membranes can be expected to be low in pulp and paper mill filtration applications. It is, however, known that fouling cannot be totally avoided even when the membrane is chosen very carefully. This study indicated that carbohydrates influenced negatively on permeability and caused fouling in the filtration of groundwood mill circulation water. Thus, a pre-treatment effectively reducing the amount of carbohydrates might help to maintain a stable capacity. However, the results of the thesis also showed that the removal of some of the possible foulants might just increase the harmful effect of others. Multivariate examination was useful in the understanding of the complicated factors causing the unstable capacity. The thesis also revealed that the 00030T and C2 membranes can be used at high pressure (max. tested pressure 12 bar). The C2 membrane, having a sponge-like substructure, was more pressure resistant, and its performance was more stable at high pressure compared to the UCO30T membrane containing macrovoids in its substructure. Both tested membranes can, according to the results, also be used at temperatures as high as 70°C in acidic, neutral and alkaline conditions. However, the use at extreme conditions might cause faster ageing of the membranes compared to ageing in neutral conditions. The thesis proved that both the tested RC membranes are very suitable for pulp and paper mill applications and that the membranes can be utilised in processes operating in challenging conditions. Thus, they could be used in more demanding applications than supposed earlier.

Genetic Factors in the Regulation of Striatal and Extrastriatal Dopamine D2 Receptor Expression

Positron emission tomography (PET) studies on healthy individuals have revealed a marked interindividual variability in striatal dopamine D2 receptor density that can be partly accounted for by genetic factors. The examination of the extrastriatal lowdensity D2 receptor populations has been impeded by the lack of suitable tracers. However, the quantification of these D2 receptor populations is now feasible with recently developed PET radioligands. The objective of this thesis was to study brain neurobiological correlates of common functional genetic variants residing in candidate genes relevant for D2 receptor functioning. For this purpose, healthy subjects were studied with PET imaging using [₁₁C]raclopride and [₁₁C]FLB457 as radioligands. The candidate genes examined in this work were the human D2 receptor gene (DRD2) and the catechol-Omethyltransferase gene (COMT). The region-specific genotypic influences were explored by comparing D2 receptor binding properties in the striatum, the cortex and the thalamus. As an additional study objective, the relationship between cortical D2 receptor density and a cognitive phenotype i.e. verbal memory and learning was assessed. The main finding of this study was that DRD2 C957T genotype altered markedly D2 receptor density in the cortex and the thalamus whereas in the striatum the C957T genotype affected D2 receptor affinity, but not density. Furthermore, the A1 allele of the DRD2-related TaqIA polymorphism showed increased cortical and thalamic D2 receptor density, but had the opposite effect on striatal D2 receptor density. The DRD2 –141C Ins/Del or the COMT Val158Met genotypes did not change D2 receptor binding properties. Finally, unlike previously reported, cortical D2 receptor density did not show any significant correlation with verbal memory function. The results of this study suggest that the C957T and the TaqIA genotypes have region-specific neurobiological correlates in brain dopamine D2 receptor availability in vivo. The biological mechanisms underlying these findings are unclear, but they may be related to the region-specific regulation of dopamine neurotranssion, gene/receptor expression and epigenesis. These findings contribute to the understanding of the genetic regulation of dopamine and D2 receptor-related brain functions in vivo in man. In addition, the results provide potentially useful endophenotypes for genetic research on psychiatric and neurological disorders.