| 1. |
- Alexakis, Alexandros Efraim, et al.
(author)
-
Modification of cellulose through physisorption of cationic bio-based nanolatexes - comparing emulsion polymerization and RAFT-mediated polymerization-induced self-assembly
- 2021
-
In: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 23:5, s. 2113-2122
-
Journal article (peer-reviewed)abstract
- The polymerization of a bio-based terpene-derived monomer, sobrerol methacrylate (SobMA), was evaluated in the design of polymeric nanoparticles (nanolatexes). Their synthesis was accomplished by using emulsion polymerization, either by free-radical polymerization in the presence of a cationic surfactant or a cationic macroRAFT agent by employing RAFT-mediated polymerization-induced self-assembly (PISA). By tuning the length of the hydrophobic polymer, it was possible to control the nanoparticle size between 70 and 110 nm. The average size of the latexes in both wet and dry state were investigated by microscopy imaging and dynamic light scattering (DLS). Additionally, SobMA was successfully copolymerized with butyl methacrylate (BMA) targeting soft-core nanolatexes. The comparison of the kinetic profile of the cationically stabilized nanolatexes highlighted the differences of both processes. The SobMA-based nanolatexes yielded high T-g similar to 120 degrees C, while the copolymer sample exhibited a lower T-g similar to 50 degrees C, as assessed by Differential Scanning Calorimetry (DSC). Thereafter, the nanolatexes were adsorbed onto cellulose (filter paper), where they were annealed at elevated temperatures to result in polymeric coatings. Their morphologies were analysed by Field Emission Scanning Electron Microscopy (FE-SEM) and compared to a commercial sulfate polystyrene latex (PS latex). By microscopic investigation the film formation mechanism could be unravelled. Water contact angle (CA) measurements verified the transition from a hydrophilic to a hydrophobic surface after film formation had occured. The obtained results are promising for the toolbox of bio-based building blocks, focused on sobrerol-based monomers, to be used in emulsion polymerizations either for tailored PISA-latexes or facile conventional latex formation, in order to replace methyl methacrylate or other high T-g-monomers.
|
|
| 2. |
- Ay, Hakan, et al.
(author)
-
Pathogenic Ischemic Stroke Phenotypes in the NINDS-Stroke Genetics Network
- 2014
-
In: Stroke. - 0039-2499. ; 45:12, s. 3589-3596
-
Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: NINDS (National Institute of Neurological Disorders and Stroke)-SiGN (Stroke Genetics Network) is an international consortium of ischemic stroke studies that aims to generate high-quality phenotype data to identify the genetic basis of pathogenic stroke subtypes. This analysis characterizes the etiopathogenetic basis of ischemic stroke and reliability of stroke classification in the consortium. METHODS: Fifty-two trained and certified adjudicators determined both phenotypic (abnormal test findings categorized in major pathogenic groups without weighting toward the most likely cause) and causative ischemic stroke subtypes in 16954 subjects with imaging-confirmed ischemic stroke from 12 US studies and 11 studies from 8 European countries using the web-based Causative Classification of Stroke System. Classification reliability was assessed with blinded readjudication of 1509 randomly selected cases. RESULTS: The distribution of pathogenic categories varied by study, age, sex, and race (P<0.001 for each). Overall, only 40% to 54% of cases with a given major ischemic stroke pathogenesis (phenotypic subtype) were classified into the same final causative category with high confidence. There was good agreement for both causative (κ 0.72; 95% confidence interval, 0.69-0.75) and phenotypic classifications (κ 0.73; 95% confidence interval, 0.70-0.75). CONCLUSIONS: This study demonstrates that pathogenic subtypes can be determined with good reliability in studies that include investigators with different expertise and background, institutions with different stroke evaluation protocols and geographic location, and patient populations with different epidemiological characteristics. The discordance between phenotypic and causative stroke subtypes highlights the fact that the presence of an abnormality in a patient with stroke does not necessarily mean that it is the cause of stroke.
|
|
| 3. |
- Bender, Johanna, 1975, et al.
(author)
-
Lipid cubic phases for improved topical drug delivery in photodynamic therapy.
- 2005
-
In: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 106:3, s. 350-360
-
Journal article (peer-reviewed)abstract
- We have evaluated the efficacy of lipid cubic phases, highly ordered self-assembly systems on the nanometer level, as drug delivery vehicles for in vivo topical administration of delta-aminolevulinic acid (ALA) and its methyl ester (m-ALA) on nude mice skin. ALA, a precursor of heme, induces the production of the photosensitizer protoporphyrin IX (PpIX) in living tissue. Measuring the PpIX fluorescence at the skin surface, after topical administration, makes indirect quantification of the penetration of ALA into the tissue possible. Cubic phases were formed of lipid (monoolein or phytantriol), water and drug. In some cases, propylene glycol was included in the cubic phase as well. The drug concentration was 3% (w/w, based on the total sample weight) in all investigated vehicles. When the formulations were applied for 1 h, the monoolein cubic systems and the three-component phytantriol sample showed higher fluorescence compared to the standard ointment during the 10 h of measurement. Both ALA and m-ALA yielded similar results, although the differences between the investigated vehicles were more pronounced when using m-ALA. For the 24-h applications, the monoolein cubic systems with m-ALA showed faster PpIX formation than the standard ointment, implying higher PpIX levels at short application times (less than 4 h). The systemic PpIX fluorescence of ALA was elevated by using the lipid cubic formulations. Notably, a small systemic effect was also observed for the monoolein cubic sample with m-ALA. These results imply improved PpIX formation when using the lipid cubic systems, most probably due to enhanced drug penetration.
|
|
| 4. |
- Brunström, Mats, 1960-
(author)
-
Matematiska resonemang i en lärandemiljö med dynamiska matematikprogram
- 2015
-
Doctoral thesis (other academic/artistic)abstract
- The overall problem that formed the basis for this thesis is that students get limited opportunity to develop their mathematical reasoning ability while, at the same time, there are dynamic mathematics software available which can be used to foster this ability. The aim of this thesis is to contribute to knowledge in this area by focusing on task design in a dynamic software environment and by studying the reasoning that emerges when students work on tasks in such an environment. To analyze students’ mathematical reasoning, a new analytical tool was developed in the form of an expanded version of Toulmin’s model.Results from one of the studies in this thesis show that exploratory tasks in a dynamic software environment can promote mathematical reasoning in which claims are formulated, examined and refined in a cyclic process. However, this reasoning often displayed a lack of the more conceptual, analytic and explanatory reasoning normally associated with mathematics. This result was partly confirmed by another of the studies. Hence, one key question in the thesis has been how to design tasks that promote conceptual and explanatory reasoning. Two articles in the thesis deal with task design. One of them suggests a model for task design with a focus on exploration, explanation, and generalization. This model aims, first, to promote semantic proof production and then, after the proof has been constructed, to encourage further generalizations. The other article dealing with task design concerns the design of prediction tasks to foster student reasoning about exponential functions. The research process pinpointed key didactical variables that proved crucial in designing these tasks.
|
|
| 5. |
- Ciornei, Cristina, et al.
(author)
-
Bactericidal/permeability-increasing protein inhibits endotoxin-induced vascular nitric oxide synthesis.
- 2002
-
In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 46:9, s. 1111-1118
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Endotoxin (lipopolysaccharide, LPS) up-regulates inducible nitric oxide synthase (iNOS) in blood vessels during septic shock. This promotes the production of nitric oxide (NO), leading to dilation of the vessels. The aim of the study was to investigate the effects of the LPS-binding endogenous antibiotic bactericidal/permeability-increasing protein (BPI) on the action of LPS on the blood vessels wall and to identify possible influence on underlying NO-related mechanisms. METHODS: Isolated segments of rat thoracic aorta and cultured primary smooth muscle cells were incubated for 5-48 h in the presence of the following combinations of compounds: (a) LPS; (b) interleukin-1beta (IL-1beta); (c) BPI; (d) BPI + LPS; (e) BPI + IL-1beta or (f) neither BPI, LPS nor IL-1beta (control). After incubation of intact segments, we measured smooth muscle contraction in response to phenylephrine and accumulation of the NO end products nitrate and nitrite in surrounding medium. Western blot was used to assess the levels of inducible nitric oxide synthase (iNOS) in cultured cells. RESULTS: Both LPS and IL-1beta decreased contractility and increased NO production, as well as iNOS. Co-incubation with BPI attenuated all the effects of LPS but only the effects of prolonged exposure to IL-1beta in cultured cells. CONCLUSION: We conclude that BPI attenuates the LPS-induced changes in vascular reactivity by inhibiting the expression of iNOS resulting in decreased NO formation and restored responsiveness to vasoconstrictors. The data suggest that BPI can prevent circulatory disturbances during Gram-negative sepsis.
|
|
| 6. |
- Dahlberg, Jonas, et al.
(author)
-
Genetic variants in serum and glucocortocoid regulated kinase 1, a regulator of the epithelial sodium channel, are associated with ischaemic stroke.
- 2011
-
In: Journal of Hypertension. - 1473-5598. ; 29, s. 884-889
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Serum and glucocorticoid regulated kinase 1 (SGK1) expression is increased by aldosterone and is a key regulator of the amiloride-sensitive sodium channel (ENaC) in the distal nephron. We have previously shown that two SNPs in SGK1 (rs1057293 and rs1743966) are associated with blood pressure variation and blood pressure progression in the general population. Therefore, we tested the association of these variants with ischaemic stroke. METHODS: Using logistic regression, we analysed rs1057293 and rs1743966 for association with ischaemic stroke in two independent age-matched and sex-matched case-control groups from the twin cities of Lund (cases n = 1837 and controls n = 947) and Malmö (cases n = 888 and controls n = 893) in the Scania region of southern Sweden. RESULTS: In additive models adjusted for hypertension, smoking and diabetes, the major allele (G) of rs1057293 was associated (odds ratio, 95% confidence interval; P value) with ischaemic stroke with similar effect size in both studies; in Lund (1.35, 1.11-1.64; P = 0.002) and Malmö (1.30, 1.03-1.65; P = 0.027). When the two studies were pooled, the overall association was 1.32, 1.14-1.52; P < 0.001. The major allele of rs1743966 (A), which was in linkage disequilibrium with rs1057293, showed a similar trend as rs1057293 G-allele but with slightly weaker effect size and P value. CONCLUSION: In two independent but ethnically similar populations, we observed an association between genetic variants in SGK1 and ischaemic stroke. Interestingly, the association seems to be at least partially independent of blood pressure. This could imply that cerebrovascular ENaC or other SGK1-regulated proteins may be of importance for development of ischaemic stroke.
|
|
| 7. |
-
Democracy and Participation – A Challenge for Special Needs Education in Mathematics : Proceedings of the 2nd Nordic Research Conference on Special Needs Education in Mathematics
- 2005
-
Editorial proceedings (other academic/artistic)abstract
- This volume contains the proceedings of the 2nd Nordic Research Conference on Special Needs Education in Mathematics, which took place at Örebro University in October 7–9, 2003. The theme of the conference was Democracy and Participation – A Challenge for Special Needs education in Mathematics. The programme included plenary lectures, paper presentations, network meetings, a round table discussion and social events. There were more than 70 participants from all Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), Germany, and the United Kingdom. One of the more important results of the conference was the establishment of a Nordic Research Network on Special Needs Education in Mathematics.
|
|
| 8. |
|
|
| 9. |
- Engström, Arne
(author)
-
Att erövra världen
- 2008
-
Conference paper (pop. science, debate, etc.)
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
- Engström, Arne, 1953-
(author)
-
De mest begåvade barnen är sämst på att lära nytt
- 2007
-
In: Dagens nyheter. - 1101-2447. ; :21 augusti, s. A6-A6
-
Journal article (pop. science, debate, etc.)abstract
- Ny studie avslöjar ökända brister: Begåvningarna behöver särskilt stöd för att inte stanna i utvecklingen. Det är en myt att begåvade barn klarar sig själva i skolan. En ny schweizisk studie visar att de begåvade barnen riskerar att misslyckas i skolan om de inte erbjuds utmaningar och får bekräftelse som andra barn.
|
|
| 13. |
- Engström, Arne, Docent, 1953-
(author)
-
Elever med mycket låga prestationer i matematik : En pilotstudie av ämnesprovet i årskurs 3
- 2017
-
Reports (peer-reviewed)abstract
- Låga prestationer i matematik är en av de europeiska utbildningssystemens stora utmaningar. Det råder stor samstämmighet om vikten av tidig upptäckt och insats för elever som är i riskzonen för att utveckla skolsvårigheter. Ett medel för detta är de nationella proven i matematik. I föreliggande rapport redogörs för en pilotstudie av elever med mycket låga prestationer på ämnesprovet i matematik för årskurs 3 i en utvald kommun. Elevernas resultat på ämnesprovet, könsskillnader samt förekomst av särskilt stöd inventeras i studien. Resultatet pekar på att situationen för elever som tidigt uppvisar mycket låga prestationer behöver uppmärksammas. De riskerar att misslyckas med att utveckla grundläggande färdigheter i skolan till en tillfredsställande nivå. Samtidigt reser studien också frågan om alla elever har förutsättningar att nå grundskolans kravnivå.
|
|
| 14. |
|
|
| 15. |
- Engström, Arne, 1953-
(author)
-
Evidence-Based Education - A challenge to special needs education in mathematics
- 2007
-
In: 3rd Nordic Research Conference on Special Needs Education in Mathematics,2005. - Aalborg : Department of Admission Courses. ; , s. 23-
-
Conference paper (peer-reviewed)abstract
- The aim of this paper is to put forward some arguments for special needs education in mathematics to be more evidence-based. Research in education is often questioned and criticised for its lack of relevance and applicability. Evidence-based education is seen as a set of principles and practices for enhancing research and practice in special needs education.
|
|
| 16. |
- Engström, Arne, et al.
(author)
-
From Henschen to Middletown Mathematics : Swedish Research on Low Achievement in mathematics
- 2010
-
In: The First Sourcebook on Nordic Research in Mathematics Education: Norway, Sweden, Iceland, Denmark and Contributions from Finland (HC). - Charlotte, NC : Information Age Publishing. - 9781617350993 ; , s. 333-346
-
Book chapter (peer-reviewed)abstract
- This chapter presents a summary of Swedish research on low achievement in mathematics from the first systematic studies of arithmetic disorder done by Salomon Eberhard Henschen to the Middletown studies carried out almost 90 years later. Henschen's case studies challenged the prevalent localization of math ability to a single brain region. He coins the term acalculia and demonstrated the complexity of mathematics as a cognitive construct. During the 1950s, Olof Magne introduced Swedish research on low achievement in mathematics with his extensive Gothenburg Studies, with 6,000 students involved. The Mathematics Clinics project tested special education methods in mathematics. The Middletown study is an investigation of students' mathematical achievements in the compulsory school system of a Swedish municipality during a period of 25 years
|
|
| 17. |
- Engström, Arne, Docent, 1953-
(author)
-
Från dyskalkyli till låga prestationer i matematik : Arvet efter Olof Magne
- 2016
-
Reports (peer-reviewed)abstract
- Matematiksvårigheter eller låga prestationer i matematik är en av de stora utmaningar som de europeiska utbildningssystemen står inför idag. Att misslyckas med skolmatematiken får stora konsekvenser för både elever och samhället.Den som kanske mer än någon annan kommit att personifiera den svenska forskningen om matematiksvårigheter är Olof Magne. Under 1950-talet arbetade han med de så kallade Göteborgsundersökningarna som omfattade 6000 folkskoleelever. Dessa följdes sedan upp av en serie interventionsstudier under 1960-talet riktade mot räknesvaga elever. Därefter påbörjade han arbetet med en kognitiv taxonomi för den elementära matematikundervisningen.De hypoteser som Magne ställde i Göteborgsundersökningarna följdes upp i det stora Medelsta-projektet. Här kan man följa utvecklingen av grundskolelevers matematikkunskaper under en period av 25 år. Den första studien i projektet gjordes 1977 och replikerades sedan vid två tillfällen 1986 och 2002.Syftet med föreliggande rapport är att beskriva och analysera Olof Magnes forskning inom området låga prestationer i matematik – vilka var frågorna, metoderna och resultatet samt var står vi idag? De frågor som restes i Magnes inledande studier för mer än 60 år sedan fortsätter att sysselsätta oss än idag.
|
|
| 18. |
- Engström, Arne, 1953-
(author)
-
Matematikvanskeligheder : nogle grundlæggende problemstillinger
- 2013. - 1
-
In: Håndbog om matematik i grundskolen. - Köpenhamn : Dansk psykologisk Forlag. - 9788777067617 ; , s. 293-307
-
Book chapter (peer-reviewed)abstract
- Kapitlet giver en introduktion ti nogle grundlæggende problemstillinger for det specialpædagogiske arbejde i skolen. Svage præstationer i matematik beskrives som et socialt problemområde. Her anlægges et systemteoretisk perspektiv, som betragter symptomer inden for problemområdet som et resultat af et samspil mellan tre faktorer: elev, matematik og omgivelser. Den store spredning mellan elever på en og samme årgang opfattes som et grundlæggende pædagogisk dilemma. Alle moderne uddannelsesystemer, der bestræber sig på at højne uddannelseniveauet, er nødt till at håndtere dette dilemma.
|
|
| 19. |
- Engström, Arne, 1953-, et al.
(author)
-
Medelsta-matematik : Hur väl behärskar grundskolans elever lärostoffet enligt Lgr 69, Lgr 80 och Lpo 94?
- 2003
-
Reports (other academic/artistic)abstract
- - Sammanfattning -Föreliggande rapport presenterar resultatet av en studie som sträcker sig över 25 år. Matematikkunskaperna hos alla grundskoleelever i en kommun har studerats vid tre olika tillfällen: 1977, 1986 och 2002. Medelsta, är en genomsnittlig kommun och grundskolan omfattar runt 2000 elever.Under tiden för studiens genomförande har tre olika läroplaner varit i kraft: Lgr 69, Lgr 80 samt Lpo 94. Läroplanerna skiljer sig åt i flera avseenden. Trots kritik som riktats mot läroplanerna under åren har tidigare ingen utvärdering gjorts av det faktiska utfallet av de olika läroplanerna.Medelsta-diagnoserna som har använts har tagits fram i samarbete med lärare i kommunen och avsikten var att täcka de elementära delarna av lärokursen i grundskolan. Varje uppgift analyserades från två utgångspunkter: dels specificerades uppgiftens årskurstillhörighet, dels klassificerades innehållet enligt de huvudområden som tillhör Magne-Thörns taxonomi.En huvudhypotes anses bekräftad: eleverna tenderar att lösa årskurstypiska uppgifter med allt lägre lösningsfrekvenser successivt under grundskoleåren. Det är framför allt de lägst presterande eleverna som drabbas av detta. Man kan här tala om en gradvis utslagning av dessa elever.Ett oväntat resultat var att lösningsfrekvenserna uppgift för uppgift och årskurs för årskurs i allt väsentligt var lika de tre åren. Det tycks som om läroplanerna spelar en försumbar roll för undervisningens resultat.
|
|
| 20. |
- Engström, Arne, et al.
(author)
-
Medelsta-matematik III : Eleverna räknar
- 2006
-
Reports (other academic/artistic)abstract
- Föreliggande studie utgör del III av undersökningarna om Medelsta-matematik. Den första delen publicerades 1990 och omfattade undersökningsåren 1977 och 1986. En andra del omfattande åren 1977, 1986 samt 2002 publicerades 2003. I del III presenteras en fördjupad undersökning av de 15 procent lägst presterande eleverna i Medelsta. I rapporten betecknas dessa elever som elever med särskilda utbildningsbehov i matematik, SUM. I 2003 års studie redovisades att den genomsnittliga prestationen för den 15 procent lägst presterande vid slutet av årskurs 9, motsvarade en genomsnittselev i årskurs fyra. Dessa skillnader i elevernas färdigheter kan observeras tidigt. I årskurs 3 motsvarar SUM-elevernas genomsnittliga prestationer vad en normal elev i årskurs 1 presterar. Skillnaderna ökar under skolåren och när SUM-eleverna nått slutet av grundskolan är de för länge sedan utslagna från skolans matematikundervisning. I rapporten redovisas också en jämförelse mellan elever med relativt sett höga prestationer och SUM-elever samt en kvalitativ studie av SUM-elevernas matematikkunskaper. En genomgripande förändring synes nödvändig omfattande skolans styrdokument, existerande undervisningspraxis i riktning mot vardagskunskaper samt en satsning på utvecklingsarbete och forskning om undervisning av SUM-elever.
|
|
| 21. |
- Engström, Arne, et al.
(author)
-
Medelsta-matematik IV : En empirisk analys av Skolverkets förslag till mål att uppnå i matematik för årskurs 3
- 2008
-
Reports (other academic/artistic)abstract
- Olika utredningar har pekat på brister i mål- och uppföljningssystemet för grundskolan. En rad förändringar av skolans styrsystem är därför aviserade eller redan beslutade av statsmakterna. En av dessa är införandet av nationella mål och prov för årskurs 3.Skolverket fick i november 2006 i uppdrag att föreslå mål och nationella prov i matematik och svenska för årskurs 3. I december 2007 överlämnade Skolverkets sitt slutliga förslag till regeringen. I föreliggande rapport analyseras Skolverkets förslag till mål att uppnå i matematik för årskurs 3. Analysen görs utifrån det empiriska forskningsmaterialet som tagits fram inom ramen för Medelsta-projektet.Vid en jämförelse med vad elever i årskurs 3 faktiskt presterar kan slutsatsen dras att Skolverkets förslag saknar realism. Endast eleverna över medianen kan förutses klara alla mål i Skolverkets förslag. Orsaken kan sökas i förslagets bristande förankring i empirisk forskning. Rapporten understryker vikten av att politiska beslut baseras på ett faktaunderlag. Den utbildningsvetenskapliga forskningen kan här ge ett viktigt bidrag. Inom en årskurs är spridningen stor mellan de lägst och de högst presterande eleverna. Redan i årskurs 3 är skillnaden flera årskurser. Denna stora variation bör formuleras som ett grundläggande pedagogiskt dilemma, något som inte kan lösas, men som likväl måste hanteras.
|
|
| 22. |
|
|
| 23. |
- Engström, Arne, 1953-, et al.
(author)
-
Problems and Improvement of the Formulations of Mathematics Teaching Objectives : An Example from the Three Dimensional Mathematics Teaching Objectives in Junior High School
- 2014
-
In: Journal of Mathematics Education. - Tianjin : Tianjin Normal University. - 1004-9894. ; 23:5, s. 23-26
-
Journal article (peer-reviewed)abstract
- On the basis of the theory of teaching objectives and the practice of mathematics teaching objectives formulating, we established a framework for analyzing mathematical teaching objectives. Based on this analytical framework, we analyzed the teaching mathematics objectives that formulated by junior school mathematics teachers from the whole structure and the specific formulations, and found some problems about formulations of mathematics teaching objectives. Finally we introduced the basic process and gave some examples about improving the quality of mathematics teqaching objectives.
|
|
| 24. |
- Engström, Arne, 1953-
(author)
-
RC is a theory of learning, not teaching
- 2014
-
In: Constructivist Foundations. - : ALEXANDER RIEGLER, CENTER LEO APOSTEL INTERDISCIPLINARY STUDIES, VRIJE UNIVERSITEIT BRUSSEL, KRIJGSKUNDESTRAAT 33, BRUSSELS, BELGIUM. - 1782-348X. ; 9:3, s. 314-316
-
Journal article (peer-reviewed)abstract
- The concept of "constructivist teaching" seems unattainable for two reasons: a philosophical and an empirical one. Also, Hugh Gash's survey is not so much about radical constructivism in education, but a review of different connected ideas labeled "constructivism" that have dominated the educational field.
|
|
| 25. |
- Engström, Arne
(author)
-
Reflective thinking in mathematics. About students' constructions of fractions
- 1997
-
Doctoral thesis (other academic/artistic)abstract
- This thesis deals with students' constructions of mathematical knowledge in the case of fractions from a radical constructivist perspective. Fractions are the first more abstracted mathematics met by students. Even if they have a rich experience of sharing and partitioning things in their everyday life dealing with fractions often give rise to difficulties in school. The thesis consists of two parts. The first part constitutes a discourse on radical constructivism in the research field of mathematics education. The second part is an empirical study wherein we discuss earlier empirical investigations of students' achievements on fractions and our own empirical inquiry. Constructivism has become one of the major influences on contemporary research in mathematics education. In our discourse we give an account of its development in the light of three main changes in the philosophy of science and mathematics during the 20th century. Radical constructivism is a theory of active knowing. Knowledge does not depict or represent an experiencer-independent reality. It serves to organize the subject's experiential world. Our world is not an unchanging independent structure, but the result of distinctions that generate a physical and a social environment to which we adapt as best we can. Reality is a reality created by the subject. Jean Piaget, in his research programme the genetic epistemology, offers two accounts for the development of human understanding. His structuralist account is concerned with the organisation of human knowledge in a system of an overarching structure. His constructivist account focus on how these structures develop through a process of equilibration. Equilibration is a process of self-regulation leading to better structures from existing ones. Learning rational numbers remains a serious obstacle in students' mathematical development. When looking at the application of rational numbers to real-world problems from an educational point of view rational numbers appears in numerous forms. A full understanding of fractions seem to require exposure to numerous rational notions. Some Swedish and foreign empirical studies are reviewed. Former attempts to elaborate hiearchical models and learning levels seem to have failed. The aim of the empirical study was to investigate the schemes that the students develop when working with fractions. We strive to build models of students' mathematical knowledge in terms of coordinated schemes of actions and operations in a Piagetian sense. The method used is the constructivist teaching experiment. It has been a long term interaction between the researcher and two groups of students, A (n=24) and B (n=19), in the intermediate grades during four years. We have made classroom observations, written tests, teaching episodes and clinical interviews with six students from each group. The schemes have been analysed and interpreted in terms of part-whole and part-part relations, N-distraction and differentiation between spatial and logico-arithmetical structures. Students' development of mathematical knowledge is achieved in an interplay between mathematical and contextual senses of a problem. The task of the teacher is to organize activities in the classroom as part of a conscious mathematization of students' experiential reality.
|
|
| 26. |
- Engström, Arne, Docent, 1953-
(author)
-
Semiotiska perspektiv i matematikdidaktik : En introduktion
- 2018
-
Reports (peer-reviewed)abstract
- Semiotiska perspektiv i matematikdidaktik har fått en ökad uppmärksamhet under senare år. I flera länder finns en livaktig forskning på området. I Sverige är semiotiska perspektiv inom matematikdidaktiken ännu svagt utvecklad. Föreliggande rapport syftar till att introducera semiotiska perspektiv inom den matematikdidaktiska forskningen. Teoretiskt inspireras dessa perspektiv av Ferdinand de Saussures och Charles S. Peirce arbeten.Människor uttrycker matematiska tankar med hjälp av tecken av olika slag. Ett tecken står för någonting. Detta någonting är i matematik ett matematiskt objekt. Matematik kan uppfattas som en generalisering av tecken eller representationssystem. En väsentlig del av den moderna matematiken handlar om symbolisering. Det är inte främst en abstraktion av den direkta verkligheten, utan om en kedja av abstraktioner. Ett matematiskt objekt eller sakförhållande kan bara förstås och kommuniceras när det representeras och tolkas i någon form. Spänningsfältet mellan sakförhållandet, representationen och tolkningen gör därför semiotiska perspektiv mycket intressanta för matematikdidaktisk forskning.
|
|
| 27. |
|
|
| 28. |
- Engström, Arne, 1953-
(author)
-
Specialpedagogiska frågeställningar i matematik
- 2015
-
Reports (other academic/artistic)abstract
- Låga prestationer i matematik är en av de stora utmaningar som de europeiska utbildningssystemen står inför. Det är en fråga som inte bara handlar om undervisningens effektivitet utan också om att skapa ett rättvist utbildningssystem. Alla moderna utbildningssystem står inför ett antal grundläggande motsättningar, eller dilemman, som i egentlig mening inte kan lösas, men likväl måste hanteras. I en skola för alla är elevernas olikheter ett grundläggande dilemma. Den gamla skolans sätt att hantera olikheterna, genom särskiljning och segregerande lösningar, har vi lämnat bakom oss. De nya utmaningar som utbildningssystemet står inför måste hanteras på andra sätt.I rapporten introduceras några specialpedagogiska frågeställningar i matematik. Matematiken fungerar som ett kritiskt filter och systemindikator för ett skolsystem. Att misslyckas i matematik får ofta större och vidare konsekvenser än att misslyckas i andra ämnen. Låga prestationer betraktas i rapporten som ett socialt problemfält. Rapporten vänder sig såväl till lärarstuderande som till verksamma lärare, som önskar en lättillgänglig introduktion till frågeställningar som lärare i matematik, speciallärare eller specialpedagoger behöver orientera sig om och ta ställning till i sin yrkesutövning.
|
|
| 29. |
|
|
| 30. |
- Engström, Maria, 1968-
(author)
-
Cheruvimskie pesnopenija v russkoj liturgičeskoj tradicii
- 2004
-
Doctoral thesis (other academic/artistic)abstract
- This thesis is a contribution to a growing field of studies on the reception of Byzantine culture in Russia. The object of investigation is the history of the Church Slavonic translation of the Cherubika, which constitute one of the most ancient and dogmatically important functional genres of Byzantine liturgical hymns. The chronological frame of this study is the 13th–17th century. Particular attention is focused on the last change in the liturgical texts in Muscovite Russia, in the mid-17th century. This liturgical reform, which led to the famous Schism in the Russian Church, is studied as part of the cultural reforms started by Tsar Alexis Romanov (1645-1676).The most characteristic feature of Orthodoxy is the principal unity of Scripture and Tradition, which in a hermeneutical perspective means the inseparability of text and context. The semiotic and interdisciplinary approach used in this study reflects this principle. The Slavic Cherubika are interpreted in a broad cultural perspective, and Church Slavonic translations are studied in the proper theological, rhetorical and linguistic contexts.Although the 17th-century translations made in Moscow were based on late Greek and South Slavic sources, they reconstruct the original dogmatic message of the Byzantine Cherubika and are hence closer to the Tradition than earlier Slavonic translations.This study offers a new interpretation of the nature of the Schism. It is shown that the main cause of the controversy between Reformists and Old Believers lies in their different understandings of the connection between Text and Ritual. The traditional medieval interpretation of the Cherubika is influenced by certain iconographical themes, other liturgical texts and the priest’s actions during the liturgy. The transition from a liturgocentric interpretation of sacral texts to a descriptive theological interpretation was a break from the characteristic Russian form of liturgocentrism and the beginning of a new cultural era.
|
|
| 31. |
- Fahlgren, Maria, 1966-
(author)
-
Designing for the integration of dynamic software environments in the teaching of mathematics
- 2015
-
Doctoral thesis (other academic/artistic)abstract
- This thesis concerns the challenge of integrating dynamic software environments into the teaching of mathematics. It investigates particular aspects of the design of tasks which employ this type of computer-based system, with a focus on improvement, both of the tasks themselves and of the design process through which they are developed and refined.The thesis reports two research projects: a small initial one preceding a larger main project. The initial case study, involving two graduate students in mathematics, develops a task design model for geometrical locus problems. The main study constitutes the first iteration of a design-based study, conducted in collaboration with four upper-secondary school teachers and their classes. It seeks to identify task design characteristics that foster students’ mathematical reasoning and proficient use of software tools, and examines teachers’ organisation of ‘follow-up’ lessons.The findings concern three particular aspects: features of tasks and task environment relevant to developing a specific plan of action for a lesson; orchestration of a particular task environment to support the instrumental genesis of specific dynamic software tools; how to follow up students’ work on computer-based tasks in a whole-class discussion.
|
|
| 32. |
- Fava, Cristiano, et al.
(author)
-
A genetic risk score for hypertension associates with the risk of ischemic stroke in a Swedish case-control study
- 2015
-
In: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 23, s. 969-974
-
Journal article (peer-reviewed)abstract
- Genetic risk scores (GRS), summing up the total effect of several single-nucleotide polymorphisms (SNPs) in genes associated with either coronary risk or cardiovascular risk factors, have been tested for association with ischemic stroke with conflicting results. Recently an association was found between a GRS based on 29 SNPs discovered by genome-wide association studies and hypertension. The aim of our study was to investigate the possible association of the same GRS with ischemic stroke on top of other ‘traditional risk factors’, also testing its potential improvement in indices of discrimination and reclassification, in a Swedish case–control study. Twenty-nine SNPs were genotyped in 3677 stroke cases and 2415 controls included in the Lund Stroke Register (LSR), the Malmö Diet and Cancer (MDC) study and the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). The analysis was conducted in the combined sample, and separately for the three studies. After adjustment for hypertension, diabetes mellitus and smoking habits, the GRS was associated with ischemic stroke in the combined sample (OR (95% CI) 1.086 (1.029–1.147) per SD increase in the GRS P=0.003) with similar trends in all three samples: LSR (1.050 (0.967–1.140); P=0.25), MDC (1.168 (1.060–1.288); P=0.002) and SAHLSIS (1.124 (0.997–1.267); P=0.055). Measures of risk discrimination and reclassification improved marginally using the GRS. A blood pressure GRS is independently associated with ischemic stroke risk in three Swedish case–control studies, however, the effect size is low and adds marginally to prediction of stroke on top of traditional risk factors including hypertension.
|
|
| 33. |
- Gidlöf, Olof, et al.
(author)
-
A Common Missense Variant in the ATP Receptor P2X7 Is Associated with Reduced Risk of Cardiovascular Events
- 2012
-
In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:5
-
Journal article (peer-reviewed)abstract
- Background and Purpose: Extracellular adenosine triphosphate (ATP) regulates inflammatory cells by activation of the P2X(7) receptor. We hypothesized that polymorphisms in P2RX7 influence the risk of ischemic heart disease (IHD), ischemic stroke (IS) and cardiovascular risk factors and tested this hypothesis using genetic association studies. Methods: Two loss-of-function SNPs in P2RX7 were genotyped in 1244 IHD cases and 2488 controls as well as 5969 individuals with cardiovascular risk factors. Eleven SNPs in a 250 kb region on chromosome 12 spanning P2RX7 as well as neighboring genes OASL, P2RX4 and CAMKK2 were genotyped in 4138 individuals with IS and 2528 controls. Association was examined using linear and logistic regression models with an additive genetic model. Results: The common loss-of-function variant rs3751143 was significantly associated with a decreased risk of IHD in smokers (P = 0.03) as well as decreased risk of IS (OR 0.89; 95% CI = 0.81-0.97; P = 0.012). In addition, an intronic SNP in CAMKK2, rs2686342, were associated with a decreased risk of IS (OR 0.89; 95% CI = 0.82-0.97; P = 0.011). In subgroup analyses, both SNPs were associated with decreased risk of IS in individuals with hypertension (P = 0.045 and 0.015, respectively). Conclusions: A common loss-of-function missense variant in the gene encoding the P2X7 receptor is associated with reduced risk of IS and with IHD in smokers. These findings might implicate a role of purinergic signaling in atherogenesis or atherothrombosis.
|
|
| 34. |
- Gregersen, Nils. P., et al.
(author)
-
Sixteen years age limit for learner drivers in Sweden : an evaluation of safety effects
- 2000
-
In: Accident Analysis and Prevention. - 0001-4575. ; 32:1, s. 25-35
-
Journal article (peer-reviewed)abstract
- Through a reform implemented in Sweden, September 1993, the age limit for practising car driving was lowered from 17½ to 16 years while the licensing age remained 18. The purpose of lowering the age limit was to give the learner drivers an opportunity to acquire more experience as drivers before being allowed to drive on their own. The primary aim of this study was to evaluate the effect of the reform in terms of accident involvement and data were therefore obtained from the national register of police reported accidents. The results show that after the reform there was a general reduction in the accident risk (accidents per 10 million km) of novice drivers with approximately 15%. Additional analyses show that the reduction of accident risk in the group who utilised the new age limit was approximately 40%, whereas those who did not utilise the prolonged training period did not benefit at all. Between 45 and 50% of the age population were found to utilise the reform. The accident reduction does not seem to be just an initial first year effect since the results were similar over 3 years of novice drivers during their first 2 years with a licence. These results suggest that the reform has been beneficial for the safety of novice drivers in Sweden. The results also suggest a potential for additional safety improvements if more young learner drivers can be brought to utilise the low age limit.
|
|
| 35. |
|
|
| 36. |
- Gregersen, Nils Petter, et al.
(author)
-
Sixteen years age limit for learner drivers in Sweden - an evaluation of safety effects
- 2000
-
In: ACCIDENT ANALYSIS AND PREVENTION. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0001-4575. ; 32:1, s. 25-35
-
Journal article (other academic/artistic)abstract
- Through a reform implemented in Sweden, September 1993, the age limit for practising car driving was lowered from 17 1/2 to 16 years while the licensing age remained 18. The purpose of lowering the age limit was to give the learner drivers an opportunity
|
|
| 37. |
|
|
| 38. |
- Hanson, Ellen, et al.
(author)
-
Genetic Variants of Coagulation Factor XI Show Association with Ischemic Stroke Up to 70 Years of Age
- 2013
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:9
-
Journal article (peer-reviewed)abstract
- Coagulation factor XI (FXI) has an important role in the propagation and stabilization of a thrombus upon vessel injury. High FXI levels have been implicated in thrombotic diseases including ischemic stroke. The aim of our study was to investigate whether FXI gene (F11) variants are associated with ischemic stroke. The discovery sample, the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), included 844 patients with ischemic stroke and 668 controls, all aged 18-70 years. Replication was performed in the Lund Stroke Register (LSR) and Malmö Diet and Cancer study (MDC), together including 1213 patients and 788 controls up to 70 years of age, and in total 3145 patients and 1793 controls (18-102 years). Seven F11 single-nucleotide polymorphisms (SNPs) were selected using a tagging approach. The SNPs rs3733403, rs925451, and rs1593 showed independent associations with overall ischemic stroke in SAHLSIS, ORs of 0.74 (95% CI 0.59-0.94), 1.24 (95% CI 1.06-1.46), and 0.70 (95% CI 0.55-0.90), respectively. The association for rs925451 was replicated in the LSR and MDC sample in a pre-specified analysis of subjects aged 70 years or younger, OR of 1.16 (95% CI 1.00-1.34), whereas no SNP was replicated when all ages were included. In line with this, one F11 haplotype was associated with overall ischemic stroke in the discovery sample and in the replication sample ≤70 years. We found significant associations between F11 variation and overall ischemic stroke up to 70 years of age. These findings motivate further studies on the role of F11 in ischemic stroke, especially in younger individuals.
|
|
| 39. |
|
|
| 40. |
- Inghammar, Malin, et al.
(author)
-
COPD and the risk of tuberculosis--a population-based cohort study.
- 2010
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:4
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Both chronic obstructive pulmonary disease (COPD) and tuberculosis (TB) primarily affect the lungs and are major causes of morbidity and mortality worldwide. COPD and TB have common risk factors such as smoking, low socioeconomic status and dysregulation of host defence functions. COPD is a prevalent co-morbid condition, especially in elderly with TB but in contrast to other diseases known to increase the risk of TB, relatively little is known about the specific relationship and impact from COPD on TB-incidence and mortality. METHODS AND FINDINGS: All individuals > or = 40 years of age, discharged with a diagnosis of COPD from Swedish hospitals 1987-2003 were identified in the Swedish Inpatient Register (n = 115,867). Records were linked to the Swedish Tuberculosis Register 1989-2007 and the relative risk of active TB in patients with COPD compared to control subjects randomly selected from the general population (matched for sex, year of birth and county of residence) was estimated using Cox regression. The analyses were stratified by year of birth, sex and county of residence and adjusted for immigration status, socioeconomic status (SES) and inpatient co-morbidities previously known to increase the risk of TB. COPD patients had a three-fold increased hazard ratio (HR) of developing active TB (HR 3.0 (95% confidence interval 2.4 to 4.0)) that was mainly dependent on an increased risk of pulmonary TB. In addition, logistic regression estimates showed that COPD patients who developed active TB had a two-fold increased risk of death from all causes within first year after the TB diagnosis compared to the general population control subjects with TB (OR 2.2, 95% confidence interval 1.2 to 4.1). CONCLUSIONS: This population-based study comprised of a large number of COPD patients shows that these patients have an increased risk of developing active TB compared to the general population. The results raise concerns that the increasing global burden of COPD will increase the incidence of active TB. The underlying contributory factors need to be disentangled in further studies.
|
|
| 41. |
|
|
| 42. |
- Inghammar, Malin, et al.
(author)
-
Increased incidence of invasive bacterial disease in chronic obstructive pulmonary disease compared to the general population-a population based cohort study
- 2014
-
In: BMC Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 14
-
Journal article (peer-reviewed)abstract
- Background: Innate defence mechanisms of the airways are impaired in chronic obstructive pulmonary disease (COPD), predisposing patients to lower respiratory tract infections, but less is known about the association with other infections. In this population-based cohort study, we investigated the associations between COPD and invasive bacterial disease by comparing incidence rates of bacteraemia in COPD patients and randomly selected reference individuals from the general population. Methods: In this population based cohort study all patients with COPD, >= 40 years of age, who were discharged from hospitals in southern Sweden between 1990 and 2003 were identified in the Swedish Inpatient Register (n = 15,403). Age and gender matched reference individuals were randomly selected from the general population. Records were cross-referenced to the microbiological databases covering the region, 1990-2010. The hazard ratios (HR) of bloodstream infections and hospitalisations for infections were estimated by Cox proportional hazards regression. Results: We found that individuals with COPD had a 2.5-fold increased incidence of bacteraemia compared to the reference individuals from the general population adjusted for other co-morbidity and socio-economic status (hazard ratio: 2.5, 95% confidence interval: 2.2-2.7). The increased incidence of bacteraemia was paralleled by an increased incidence of hospitalisation for non-respiratory infections, i.e., skin infections, pyelonephritis, or septic arthritis. Despite higher absolute rates of bloodstream infections among COPD patients than among the general population, the distribution of different pathogens was similar. Conclusions: In summary this population-based study shows COPD is associated with an increased incidence of invasive bacterial infections compared to the general population, indicating a general frailty of acquiring severe infections in addition to the specific susceptibility to infections of respiratory origin. The underlying contributory factors (e. g. smoking, corticosteroid use, co-morbid diseases or a frailty inherent to COPD itself) need to be disentangled in further studies.
|
|
| 43. |
- Inghammar, Malin, et al.
(author)
-
Invasive pneumococcal disease in patients with an underlying pulmonary disorder.
- 2013
-
In: Clinical Microbiology and Infection. - : Elsevier BV. - 1469-0691 .- 1198-743X. ; 19:12, s. 1148-1154
-
Journal article (peer-reviewed)abstract
- Chronic pulmonary disease is a recognized risk factor for invasive pneumococcal disease (IPD). However, previous studies have often not been large enough to allow detailed analyses of less prevalent pulmonary diseases, and findings regarding case fatality have been inconsistent. We examined the associations between an underlying pulmonary disease and IPD, and the impact of these diseases on the case fatality rate. Patients with IPD ≥18 years of age, between 1990 and 2008, were identified in microbiological databases. The associations between IPD and the pulmonary diseases were assessed using conditional logistic regression, comparing IPD cases to ten control subjects per case, randomly selected from the general population (matched for gender, year of birth and county of residence). Adjustments were made for other co-morbidities, level of education and socio-economic status, 4085 cases of IPD and 40 353 controls were identified. A more than four-fold increased risk of IPD was seen in chronic obstructive pulmonary disease, a doubled risk in asthma and a five-fold increased risk in subjects with pulmonary fibrosis. In univariate analysis, sarcoidosis and bronchiectasis were associated with a two-fold to seven-fold increase in the risk of IPD, but there was no statistical support for the associations when adjustments for confounders were made. No increased risk was seen in subjects with a history of pneumoconiosis or allergic alveolitis. The mortality following IPD was not increased in patients with chronic obstructive pulmonary disease, asthma, pulmonary fibrosis or bronchiectasis. Several chronic pulmonary diseases increase the risk of IPD but mortality following IPD seems not to be affected.
|
|
| 44. |
- Inghammar, Malin, et al.
(author)
-
Validation of a COPD diagnosis from the Swedish Inpatient Registry.
- 2012
-
In: Scandinavian Journal of Public Health. - : SAGE Publications. - 1651-1905 .- 1403-4948.
-
Journal article (peer-reviewed)abstract
- Aims: The Swedish National Inpatient Registry is an important source of data for numerous epidemiological studies, amongst them studies on chronic obstructive pulmonary disease (COPD). General validation studies indicate that in general 85-95% of diagnoses reported are correct, but this is not true for all groups of diseases, why specific validation studies are of great importance. Methods: Charts from 374 individuals discharged with a COPD diagnosis between 2000-07 from two central hospitals and two university hospitals in the county of Skåne were validated against the original medical files. Criteria for the degree of certainty of the COPD diagnosis were predefined and the association between predictors of diagnostic probability and the level of certainty was assessed using an ordinal logistic regression model. Results: According to the Global Initiative for Chronic Obstructive Lung Disease criteria, 21.7% of the diagnosis were classified as proven COPD, 35.5% were classified as probable, another 34.0% as possible COPD, 2.1% were classified as having an uncertain diagnosis, and 7.0% as an unlikely COPD diagnosis. Age category (adjusted ORs: 60-79 years, 2.6, 95% CI 1.2-5.4; ≥80 years, 1.6, 95% CI 0.7-3.3) and discharge from a non-surgical department (adjusted OR: 1.7, 95% CI 1.1-2.8) were significantly associated with higher level of diagnostic certainty. Conclusions: A COPD diagnoses from the Swedish Inpatient Registry is of acceptable validity for epidemiological research. The degree of certainty of the diagnosis varies but less than 10% were considered as misclassified or having an uncertain COPD diagnosis.
|
|
| 45. |
|
|
| 46. |
|
|
| 47. |
|
|
| 48. |
|
|
| 49. |
- Liu, Yang, 1960-
(author)
-
Syllogistic Analysis and Cunning of Reason in Mathematics Education
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- This essay explores the issue of organizing mathematics education by means of syllogism. Two aspects turn out to be particularly significant. One is the syllogistic analysis while the other is the cunning of reason. Thus the exploration is directed towards gathering evidence of their existence and showing by examples their usefulness within mathematics education.The syllogistic analysis and the cunning of reason shed also new light on Chevallard's theory of didactic transposition. According to the latter, each piece of mathematical knowledge used inside school is a didactic transposition of some other knowledge produced outside school, but the theory itself does not indicate any way of transposing, and this empty space can be filled with the former.A weak prototype of syllogism considered here is Freudenthal's change of perspective. Some of the major difficulties in mathematics learning are connected with the inability of performing change of perspective. Consequently, to ease the difficulties becomes a significant issue in mathematics teaching. The syllogistic analysis and the cunning of reason developed in this essay are the contributions to the said issue.
|
|
| 50. |
- Ljung Aust, Mikael, et al.
(author)
-
Effects of forward collision warning, initial time headway and repeated scenario exposure on driver response in emergency lead vehicle braking scenarios
- 2011
-
Reports (other academic/artistic)abstract
- To address the research questions, acritical lead vehicle braking scenario and anFCW system was developed and pilot tested in Saab’s fixed based driving simulator in Trollhättan. After piloting, the scenario was implemented in VTI’s moving base simulatorin Linköping, and the effects,of FCW presence, two different initial time headways at visual distraction task onset and repeated scenario exposure, on driver response timeswere examined.The study showed significant effects of FCW and repeated scenario exposure on response times. Moreover, these effects were not additivei.e. a significant interaction between the two was found. There was also a significant effect on responsetimes ofinitial time headway at onset of the visual distraction task. In addition, an interaction between initial time headway and repeated scenario exposure was found for drivers with FCW, but not for drivers without FCW. A second objective of the project was to compare the extent to which the VTI moving base simulator with motion cues generates similar driver responses(quantitatively and qualitatively)as the static simulator set-up at Saab. In general, theresults from this project have important implications for the interpretation of driver performance in experimental settings, particularlywhen aiming toevaluate safety-related in-vehicle information and warning technologies. For onething,they pose a general question markaround the generalizabilityof results to real world events. Second, a future prerequisite for FCW studies should probably be that test drivers have a previous level of system exposure level which matchesthat of real world drivers encountering typical critical events. Also, tuning the initialtime headwayat distraction task onsetin the experimentalsetting to real world conditions is of critical importance.
|
|
