Beräkningar av subtraktionsuppgifter visar sig vara en utmaning för svenska elever i årskurs 3. Problematiken ligger i valet av beräkningsmetoder, där dessa inte är lika effektiva och framgångsrika som vid beräkningar av addition. Denna studie är inspirerad av en fenomenografisk ansats, som syftar till att redogöra för vilka uppfattningar elever i årskurs 3 har av subtraktion, samt vad som påverkar elevers metodval vid beräkningar av subtraktion. Studiens syfte besvaras med följande frågeställningar; hur uppfattar elever subtraktion? Vilka aspekter påverkar elever att välja en specifik metod vid beräkningar av olika subtraktionsuppgifter? Med utgångspunkt från semistrukturerade individuella intervjuer med 10 elever från två klasser i årskurs 3, visar det sig att samtliga elever inledningsvis uppfattar räknesättet subtraktion som en subtraktiv förändring, där något försvinner eller tas bort. Vid beräkning av sex olika subtraktionsuppgifter; tre textuppgifter och tre uppgifter med okända tal, visar eleverna en variation i att vara flexibel respektive anpassningsbar i metodvalet. Resultatet redovisar kategorier som representerar olika beräkningsmetoder. Inom respektive kategori lyfts elevers egna beräkningar inklusive deras motiveringar till valet av beräkningsmetod.  Standardalgoritmen visar sig vara den dominanta beräkningsmetoden, där ett fåtal elever använder standardalgoritmen vid samtliga uppgifter. Där valet av att använda standardalgoritmen som beräkningsmetod beror på att metoden är enklast att använda och att det går fort att räkna ut svaret med standardalgoritmen. I resultatet hävdar eleverna även att valet av metod beror till stor del på de ingående talens värde i den givna uppgiften. / Calculations of subtraction tasks has shown to be challenging for Swedish pupils in grade 3. The problem lies in the choice of calculation methods, where these methods aren´t as effective and successful as those methods for calculations of addition.  This study is inspired by a phenomenographic approach and aims to explain what perceptions pupils in grade 3 has of subtraction, and what affects pupils’ choice of methods in calculations of subtraction. The aim in the study focuses on the following questions; how do pupils perceive subtraction? Which aspects influence pupils to choose a specific method when calculating different subtraction tasks? Based on semi-structured individual interviews with 10 pupils from two classes in grade 3, it turns out that all pupils initially perceive subtraction as a subtractive change, where something disappears or is taken away. In the calculations of six different subtractions task; three text tasks and three tasks with unknown numbers, the pupils show a variation by being flexible and adaptable in their choice of method. The result reports categories that represents different calculation methods. In each category, pupils own calculations is mentioned including their motivations for the choice of calculation method. The standard written algorithm is shown to be the most dominant calculation method, where a few pupils use the standard algorithm in all tasks. The choice to use the standard algorithm as calculation method is due to the simplicity of the method and that it´s faster to calculate the answer with the standard algorithm. In the result, the pupils also claims that the choice of methods depends on the value of the including numbers in the given task.

The purpose of this study is to observe some factors that may affect the understanding of subtraction with borrowing. The study is done in a foreign environment, in Kenya. Factors that will be looked into are: the classroom environment, the situation of learning in a second language. The study will also observe factors that can cause an erroneous answer and what those may look like. Within this area manipulatives will be mentioned. The study has used a qualitative as well as quantitative approach. The qualitative method has been accomplished through interviews and observations, the quantitative method through tests given to the learners. For the analysis of the observations, Cobb’s and Yackel’s model (1995) of the mathematical classroom has been used. The study is interpreted from a sociocultural perspective focusing interaction. The result in this study shows that the interaction in the classroom is important to the individual learning, perceptions of mathematics and the expectations on the individual. Learning in a second language can be a barrier. The use of manipulatives can work as a scaffold, but it can also hinder the learner to develop a deeper understanding. / Syftet med studien är att studera faktorer som kan påverka förståelsen av subtraktion med växling. Studien är gjord i en annan lärmiljö, i Kenya. Faktorer som kommer att uppmärksammas är lärmiljön i klassrummet och att inlärningen sker på ett för eleven andra språk. Studien kommer också att uppmärksamma faktorer som kan bidra till ett felaktigt svar och hur de kan se ut. Inom detta område kommer laborativt material nämnas. Studien har både ett kvalitativt och kvantitativt tillvägagångssätt. Den kvalitativa metoden har genomförts genom intervjuer och observationer, den kvantitativa metoden med hjälp av elevtester. Cobbs och Yackels (1995) modell över matematik klassrummet har använts som analysmaterial. Studien tolkas utifrån ett sociokulturellt perspektiv. Focus är på interaktionen.   Resultaten i studien visar att interaktionen I klassrummet är viktigt för det individuella lärandet, uppfattningen om matematik och förväntningar på individen. Undervisning på ett andra språk kan bli ett hinder. Användandet av laborativt material kan fungera som ett stöd, men kan också hindra utvecklandet av en djupare förståelse.

Analýza medicínských obrazů je předmětem základního výzkumu již řadu let. Za tu dobu bylo v této oblasti publikováno mnoho výzkumných prací zabývajících se dílčími částmi jako je rekonstrukce obrazů, restaurace, segmentace, klasifikace, registrace (lícování) a fúze. Kromě obecného úvodu, pojednává tato disertační práce o dvou medicínsky orientovaných tématech, jež byla formulována ve spolupráci s Philips Netherland BV, divizí Philips Healthcare. První téma je zaměřeno na oblast zpracování obrazů subtrakční angiografie dolních končetin člověka získaných pomocí výpočetní X-Ray tomografie (CT). Subtrakční angiografie je obvykle využívaná při podezření na periferní cévní onemocnění (PAOD) nebo při akutním poškození dolních končetin jako jsou fraktury apod. Současné komerční metody nejsou dostatečně spolehlivé už v předzpracování, jako je například odstranění pacientského stolu, pokrývky, dlahy, apod. Spolehlivost a přesnost identifikace cév v subtrahovaných datech vedoucích v blízkosti kostí je v důsledku Partial Volume artefaktu rovněž nízká. Automatické odstranění kalcifikací nebo detekce malých cév doplňujících nezbytnou informaci o náhradním zásobení dolních končetin krví v případě přerušení hlavních zásobujících cév v současné době rovněž nesplňují kritéria pro plně automatické zpracování. Proto hlavním cílem týkající se tohoto tématu bylo vyvinout automatický systém, který by mohl současné nedostatky v CTSA vyšetření odstranit. Druhé téma je orientováno na identifikaci patologických změn na páteři člověka v CT obrazech se zaměřením na osteolytické a osteoblastické léze u jednotlivých obratlů. Tyto změny obvykle nastávají v důsledků postižení metastazujícím procesem rakovinového onemocnění. Pro detekci patologických změn je pak potřeba identifikace a segmentace jednotlivých obratlů. Přesnost analýzy jednotlivých lézí však závisí rovněž na správné identifikaci těla a zadních segmentů u jednotlivých obratlů a na segmentaci trabekulárního centra obratlů, tj. odstranění kortikální kosti. Během léčby mohou být pacienti skenováni vícekrát, obvykle s několika-mesíčním odstupem. Hodnocení případného vývoje již detekovaných patologických změn pak logicky vychází ze správné detekce patologií v jednotlivých obratlech korespondujících si v jednotlivých akvizicích. Jelikož jsou příslušné obratle v jednotlivých akvizicích obvykle na různé pozici, jejich fúze, vedoucí k analýze časového vývoje detekovaných patologií, je komplikovaná. Požadovaným výsledkem v tomto tématu je vytvoření komplexního systému pro detekci patologických změn v páteři, především osteoblastických a osteolytických lézí. Takový systém tedy musí umožnovat jak segmentaci jednotlivých obratlů, jejich automatické rozdělení na hlavní části a odstranění kortikální kosti, tak také detekci patologických změn a jejich hodnocení. Ačkoliv je tato disertační práce v obou výše zmíněných tématech primárně zaměřena na experimentální část zpracování medicínských obrazů, zabývá se všemi nezbytnými kroky, jako je předzpracování, registrace, dodatečné zpracování a hodnocení výsledků, vedoucími k možné aplikovatelnosti obou systému v klinické praxi. Jelikož oba systémy byly řešeny v rámci týmové spolupráce jako celek, u obou témat jsou pro některé konkrétní kroky uvedeny odkazy na doktorskou práci Miloše Malínského.

L’objet de cette thèse est de mesurer l’impact cognitif d’un dispositif didactique sur des élèves de CE2 en difficulté d’apprentissage, pris en charge dans le cadre d’un RASED, au sujet de la résolution de problèmes additifs. Nous étudions comment, et avec quelle variabilité, les différents leviers du dispositif, volontairement conjugués et sous-tendus par nos choix théoriques, provoquent une évolution cognitive chez ces élèves. Cette thèse s’appuie de manière centrale sur les travaux de plusieurs auteurs psychologues et didacticiens, notamment : Vergnaud, Julo, Brousseau, Piaget et Vygotski. L’expérimentation porte sur 25 élèves, qui, par groupes de 4 ou 5, ont bénéficié de ce dispositif constitué de 13 séances de 45 min. Un pré-test et un post-test permettent une mesure de l’évolution de ces élèves. Les résultats montrent que ce dispositif permet, en général, de faire progresser ces élèves en difficulté, que ces progrès dépendent de leurs connaissances initiales, mais que ces connaissances n’expliquent pas totalement la variabilité des progrès constatés. Enfin, nous tentons de comprendre pour quels élèves nos hypothèses concernant la pertinence des différents leviers se vérifient. Pour cela, nous analysons dans le détail, au cours de chacune des 13 séances, les activités mathématiques et langagières de certains élèves représentatifs des groupes que nous mettons en évidence. Ainsi, l’apport de cette thèse consiste également à discuter l’intérêt et les limites de notre dispositif en fonction des élèves qui constituent le public pris en charge dans le cadre des RASED. / The aim of this thesis is to measure the cognitive impact of a didactic framework on the pupils of CE2 with learning difficulties, under the care of the Special Needs network (RASED), in relation to the resolution of problems in addition and subtraction. We are studying how, and with what variability, the different tools within the framework, deliberately selected in accordance with our theoretical models, engender cognitive development in these pupils. This thesis is centred around the work of several psychologists and educationalists, notably : Vergnaud, Julo, Brousseau, Piaget and Vygotski. The research is based on 25 pupils, in groups of 4 or 5, who benefitted from a programme of 13 lessons of 45 minutes each. Testing before and after allows the measurement of the progress of these pupils. The results show that the programme helps, in general, pupils with difficulty to make progress, that this progress depends on their initial skills, but that those skills do not completely explain the variability of the progress observed. Finally, we try to understand for which pupils our hypotheses regarding the relevance of different tools are verified. For that, we analyse in detail, during the course of each of the 13 lessons, mathematical and linguistic activities of certain pupils representative of the groups we are presenting as evidence. In addition, the focus of this thesis comprises also a consideration of the benefits and limitations of our programme in relation to the pupils who are the subjects under the aegis of the RASED.

Desde a introdução dos implantes na Odontologia, controvérsias tem havido acerca da propriedade de conectar os implantes a dentes em próteses fixas. Os implantes osseointegrados não apresentam nenhum ligamento periodontal e são mais firmemente ancorados ao osso. A diferença apresentada nesta ancoragem tem levantado preocupações acerca de o implante osseointegrado, por sua firme fixação ao osso, apresentar pouca flexibilidade para dividir as cargas funcionais com os dentes conectados. O presente estudo teve como propósito acompanhar prospectivamente os parâmetros periodontais ? índice gengival, índice de sangramento, profundidade de sondagem e perda de inserção entre o dente pilar de uma prótese dento-implanto-suportada com o dente colateral do mesmo paciente, e também os parâmetros peri-implantares dos implantes que suportam estas próteses - índice gengival; índice de sangramento; profundidade de sondagem e perda de inserção. Para verificar a perda de inserção foi utilizado o recurso da subtração radiográfica da região em que a prótese foi instalada, com tomadas radiográficas efetuadas no momento da instalação da prótese, decorridos seis meses e após 12 meses de uso, com o objetivo de verificar a ocorrência, ou não, de alteração do suporte ósseo peri-implantar. Foram selecionados 12 pacientes com estado de saúde normal, apresentando área posterior de mandíbula edêntula onde estava indicada a reabilitação protética por meio de prótese fixa unindo dente a implante. Estes foram tratados com implante de um estágio de 10 mm padrão da Straumann (ITI), que apresenta um pescoço polido de 2.8mm, onde a porção do implante que permanece intra-óssea apresenta uma superfície tratada, com diâmetro de 4.1mm. O implante foi instalado no espaço onde se localizaria o retentor mais distal da futura prótese parcial fixa, seguindo o protocolo. As radiografias digitais obtidas foram avaliadas num software de subtração radiográfica, Matrox Inspector versão oito, para verificar a alteração da variação de densidade óptica e contraste das radiografias quando superpostas, sendo os valores observados no implante comparados com os critérios de sucessos , amplamente abordados nos estudos verificados. Todos os implantes instalados nos pacientes osseointegraram, não houve registro de alteração óssea ao redor dos mesmos e nos dentes pilares das próteses em avaliações feitas após seis meses e 12 meses. As próteses continuaram clinicamente em excelente estado após 12 meses de avaliação nas análises clínicas e radiográficas. Ainda, de acordo com o teste de Sinais de Postos de ilcoxon, concluiu-se estatisticamente que não houve diferença nos parâmetros peri-implantares de cada paciente durante os períodos analisados (zero, seis meses e 12 meses), bem como quando comparados com os respectivos dentes colaterais. / Since the introduction of implants in Dentistry, controversies have arisen about the possibility of connecting implants to teeth in fixed prostheses. Osseointegrated implants do no present any periodontal ligature and are more firmly anchored to the bone. The difference presented by this type of anchorage has led to some concern about the limited flexibility of the osseointegrated implant to share the functional loads with the connected teeth. This study intended to follow-up prospectively the periodontal parameters bleeding index, probing depth between the pillar tooth of an implant supported prosthesis with one control tooth of the same patient and also the implants that support theses prostheses. That is why subtraction radiography of the region in which the prosthesis was placed was used, with radiographs taken at prosthesis placement, after six months and one year of use to verify if the periimplant osseous support had or had not undergone changes. Twelve patients with normal health conditions were selected who presented a posterior area edentulous jaw where a prosthetic rehabilitation by a fixed prosthesis joining tooth to implant was indicated. Patients were treated with an implant of one stage of 10mm standard Straumann (ITI) with a 2.8 mm polished neck, in which the remaining intraosseous portion of the implant has a treated surface of 4.1 mm diameter. The implant was placed in the space where according to the protocol, the more distal retainer of the future fixed partial prosthesis would be located. Digital radiographs were assessed with a subtraction radiography software Matrox Inspector version eight, to corroborate the change of contrast in the radiographs when superimposed, with values observed in the implant compared with the success criteria , widely mentioned in surveyed studies. All implants placed in patients became osseointegrated. There was no record of bone change around them and in the dental pillars of the prostheses at the one year follow-up. Prostheses continue to be in excellent conditions after the one year follow-up based upon clinical and radiographic analyses. Furthermore, in accordance with the Wilcoxon test of matched pairs and signed rank, it was concluded that there was no statistical difference between each group of each patient during the time period analyzed (baseline and one year) as well as when the pillars were compared to their respective controls.

A colonização bacteriana no sulco periimplantar ocorre muito precocemente, logo após a cirurgia de instalação dos implantes. Com este intuito, o projeto foi proposto a fim de avaliar o efeito da terapia fotodinâmica (PDT) na manutenção da crista óssea alveolar. Em um estudo de boca dividida, 20 pacientes foram reabilitados com implantes Standard Plus (Straumann®), divididos em dois grupos: um grupo controle (GC) e um grupo submetido à terapia fotodinâmica (GPDT), cujo protocolo foi: densidade de energia 120J/cm2, potência de 40mW, associada ao corante azul de metileno a 0,005%. As aplicações foram realizadas no dia da instalação do implante, após 15, 30 e 45 dias. As coletas microbiológicas foram efetuadas no período inicial e 6ª semana, nos dois grupos, utilizando cones de papel estéril. No GPDT, outras duas coletas foram realizadas após aplicação da terapia: no dia da cirurgia e após 45 dias. As unidades formadoras de colônias totais (UFCt) e pigmentadas de preto (UFCpig) foram contadas. Dados clínicos (Índice de Placa- IP e Sangramento a Sondagem- SS modificados por Mombelli) foram obtidos na 6a semana, 6 meses e 1 ano. Análise radiográfica, com radiografias periapicais, foram efetuadas utilizando a técnica da subtração radiográfica. As películas foram digitalizadas com o escaner SprintScan 35 Plus - Polaroid. Com softwares de manipulação de imagens (Adobe Photoshop CS2®- Califórnia, EUA e ImageJ- National Institutes of Health) foram medidas as distâncias do ombro do implante ao primeiro contato implante-osso, nas seguintes fases: inicial; 6a semana; instalação da prótese, 6 meses e 1 ano após instalação protética. Os testes estatísticos aplicados foram Friedman, Wilcoxon e MannWhitney. Quanto à eficiência da PDT, os resultados mostraram que houve uma redução, estatisticamente significante, tanto para UFCt como UFCpig nos dois momentos aplicados. O número de UFCt e UFCpig do pós-cirúrgico até a 6ª semana apresentou aumento, estatisticamente significante, nos dois grupos. No comparativo entre grupos não houve diferença, estatisticamente significante, entre a diferença do número de UFCt e UFCpig do período inicial ate a 6ª semana. O IP e SS foram similares entre os dois grupos. A avaliação radiográfica mostrou que houve uma perda da crista óssea crescente do período inicial até a instalação da prótese, que se manteve mantém estável após um ano de função para os dois grupos. A média da perda óssea, do período inicial até a instalação da prótese, foi de 0,73mm para o GC e de 0,84mm para o GPDT. Durante o período de função protética as médias de perda óssea foram, respectivamente, 0,27mm e 0,19mm para os GC e GPDT, sem diferença estatisticamente significante entre os grupos. Concluiu-se que: a PDT é eficiente para a redução das UFCt e UFCpig, presentes no sulco periimplantar, durante a osteointegração; a PDT não impede a recolonização, nem o crescimento bacteriano ao longo do tempo, exceto as UFCpig do GPDT, onde a quantidade de bactérias durante a osteointegração manteve-se estatisticamente estável; e com relação à manutenção da crista óssea periimplantar, os GC e GPDT tiveram resultados similares, sem diferença estatisticamente significante. / Bacterial colonization of the peri-implant sulcus occurs very early, right after the implant placement surgery. To this purpose, the project was proposed to evaluate the effect of photodynamic therapy (PDT) in the maintenance of {the} alveolar bone crest. In a split-mouth study, 20 patients were rehabilitated with Standard Plus implants (Straumann®) and they were divided into two groups: a control group (CG) and a group submitted to photodynamic therapy (GPDT), whose protocol was: energy density of 120J/cm2 at power of 40 mW, combined with 0,005% methylene blue. The applications were performed on the day of implant placement, after 15, 30 and 45 days. Microbiological samples were collected in the initial period and after 6 weeks on both groups, using sterile paper cones. In GPDT, two other collections were made after the application of the therapy: on the day of surgery and after 45 days. The total colony forming units (UFCt) and pigmented black units (UFCpig) were counted. Clinical data (Plaque Index-IP and Sulcus bleeding index- SS modified by Mombelli) were obtained at the 6th week, 6 months and 1 year. Radiographic analysis with periapical radiographs were made using the radiographic subtraction technique. The films were digitalized with the scanner SprintScan 35 Plus- Polaroid. Using image manipulation softwares (Adobe Photoshop® CS2- California and ImageJ-National Institutes of Health) distances from the implant shoulder to the first bone-implant contact were measured in phases: initial; 6th week; installation of the prosthesis, 6 months and 1 year after prosthetic installation placement. Friedman, Wilcoxon and Mann-Whitney were the statistical tests applied. Concerning the PDT efficacy, the results presented a statistically significant reduction for both UFCt and UFCpig in the two performed moments. The number of UFCt and UFCpig of the immediate postoperative to 6 weeks indicated a statistically significant increase in both groups. Comparing both the two groups, there was no statistically significant difference between the number of UFCt and UFCpig of the initial period to the 6th week. The IP and SS were similar in both groups. Radiographic evaluation indicated that there was an increasing loss of bone crest during the initial period and the installation of the prosthesis, which remained stable after a year of function for both groups. The bone loss average from the initial period until the installation of the prosthesis was 0,73mm for the GC and 0,84mm for the GPDT. During the prosthetic function the bone loss averages were, respectively, 0,27mm and 0,19mm for the GC and for the GPDT, with no statistically significant difference for both groups. The data led to the conclusion that: PDT is effective in reducing UFCt and UFCpig present in the peri-implant groove during the osseointegration; the PDT does not avoid the re-colonization or bacterial growth over time, except for the UFCpig of GPDT, wherein the amount of bacteria during the osseointegration remained statistically stable; and regarding to the maintenance of the peri-implant bone crest, the GC and GPDT obtained had similar results, with no statistically significant difference.

Das Ziel: der Arbeit war die Überprüfung der Aussagekraft der MRA in time-of-flight-technique der Arteria caroits bei 1,0 Tesla im Vergleich zur intaarteriellen DSA und der Wertigkeit in der Einsatzfähigkeit in der klinischen Routine bei der Diagnostik von Carotisstenosen. 101 Patienten wurden zur Abklärung einer Stenose der Arteria carotis vergleichend mittels TOF-MRA und i.a. DSA der Arteriae carotis untersucht. Morphologische Veränderungen wurden für sämliche Gefässe erfasst, wobei die Stenosen der Arteriae carotis entsprechend den NASCET-Kriterien graduiert wurden (geringgrade, mittelgradige,hochgradige Stenose oder Verschluss).Die Ergebnisse wurden mit folgenden drei verschiedenen statistischen Tests ausgewertet: Kappa Test, gewichteter Kappa Test und Intraklassenkorrelationskoeffizient. Von den 84 in die Auswertung eingebezogenen Gefässen wurden 66 Stenosen in der DSA als geringgradig klassifiziert. In dieser Kategorie wurden 60 dieser Stenosen von der MRA korrekt als geringgradig klassifiziert. In der DSA wurden 60 Stenosen der Arteria carotis als mittelgradig klassifiziert. 29 dieser Stenosen wurden von der MRA korrekt als mittelgradig eingeschätzt. 21 Stenosen wurden von der DSA als hochgradig klassifiziert. 20 dieser Stenosen wurden von der MRA korrekt als hochgradige Stenosen eingeschätzt. Die 16 kompletten Gefäsverschlüsse wurden alle von der MRA detektiert. Der Kappa Test ergab eine starke Korrelation der Ergebnisse. Insgesamt zeigte sich eine gute Überstimmung zwischen MRA und DSA. Aber gerade im Bereich der mittelgradigen Stenosen neigte die MRA dazu den Stenosegrad zu überschätzen. Das Ziel der Gefässdiagnostik ist eine präzise und reproduzierbare Bestimmung des Stenosegrades. Die Magnetresonanzangiographie kann als eine akkurate und zuverlässige Methode zur Bestimmung von Carotisstenosen angesehen werden / The purpose was to evaluate the efficiacy of the time-of-flight MRA of the carotid artery with a 1.0 Tesla system in comparison to intraarterial digital subtraction angiography for the assessment of carotid artery disease. 101 patients with suspected stenosis of the carotid artery were examined with a 1.0 Tesla scanner in time-of-flight-technique and with the selective i.a. DSA in parallel. Morphological pathologies were registered for all arteries, stenosis of the internal carotid artery of both examinations were blindly graded by applying the NASCET criteria (mild, moderately, severely or occluded). Three different assessment methods were conducted for the MRA data. Kappa, weighted kappa, intraclass correlation were calculated for MRA results compared to DSA. Of the 84 common carotid bifurcation, 66 were classified as mild stenosis by DSA. In this category, MRA correctly identified 60 of these as mild stenosis. Among 60 common carotid artery bifurcation graded as moderate by DSA, 29 were correctly graded as moderate by MRA. Among 21 common carotid artery bifurcation graded as severe by DSA, 20 of these were correctly graded by the MRA. There were 16 complete occlusions which were all correctly graded by MRA. A good kappa value was calculated for the data. In general the MRA were considered to find a good agreement with the DSA, but tended to overestimate stenosis, especially in the range of moderate stenosis. The aim of diagnosis is exact grading of carotid stenosis. MRA with its high agreement with DSA can be regarded as an accurate screening method of the common carotid bifurcation.

Die Thrombozytenaktivierung ist von zentraler Bedeutung für die Pathogenese der Arteriosklerose und wird bei Patienten mit instabiler Angina pectoris, Myokardinfarkt und TIA sowie nach koronarangioplastischen und operativen Eingriffen als Verursacher okklusiver vaskulärer Ereignisse in Betracht gezogen. Wir gingen der Frage nach, ob ein Zusammenhang zwischen peripherer arterieller Verschlußkrankheit (PAVK) und der Aktivierung zirkulierender Thrombozyten besteht und ob die intraarterielle digitale Subtraktionsangiographie (DSA) sowie die perkutane transluminale Angioplastie (PTA) im Bereich der unteren Extremitäten die Aktivierung zirkulierender Plättchen beeinflussen. Unsere Studie schloß 16 Kontrollprobanden mit PAVK, 25 gesunde Kontrollprobanden und 36 Patienten ein, von denen 14 einer DSA, 12 einer PTA und 10 beiden Eingriffen unterzogen wurden. Wir entnahmen Blutproben aus einer peripheren Vene oder aus Einführungsbestecken in der Arteria und Vena femoralis vor, direkt nach und 4 h nach den Interventionen. Die Plättchenaktivierung wurde anhand durchflußzytometrischer Messungen der Expression aktivierungsspezifischer Antigene (CD62 und CD63) bestimmt, die Sensibilität der Thrombozyten analysierten wir mittels einer zusätzlichen in-vitro-Aktivierung. Wir beobachteten 4 h nach der DSA einen Abfall der Aktivierung und eine erhöhte Sensibilität von Plättchen im arteriellen und venösen Strombereich (p < 0,02). Wir sehen diese Wirkungen als Kontrastmittel(KM)-induziert an und führen die Abnahme der Relativzahl aktivierter Thrombozyten hauptsächlich auf ihre verkürzte Lebensdauer zurück. 4 h nach der PTA kam es arteriell und venös zu einem Abfall der Relativzahl aktivierter Thrombozyten (p < 0,02). Weiterhin beobachteten wir unmittelbar nach der PTA eine Verringerung des prozentualen Anteils aktivierter Plättchen in der arteriellen Zirkulation (p = 0,021) in Korrelation mit zunehmenden Dilatationszeiten und Ballonlängen (p < 0,03). Diese Beobachtungen führen wir auf eine geringe Anlagerung bzw. reduzierte Lebensdauer aktivierter Thrombozyten zurück. Von geringer quantitativer Bedeutung waren Einflüsse des Heparins und KM. Die Wirkung der DSA und PTA auf die Thrombozytenfunktionen schien sich in den 4 postinterventionellen Stunden abzuschwächen. Unsere Ergebnisse zeigen, daß die Angioplastie in peripheren Gefäßen eine Aktivierung und vermutlich geringe Anlagerung bzw. verkürzte Lebensdauer zirkulierender Plättchen unmittelbar nach der PTA und 4 Stunden später verursacht. Diese Prozesse führen wir in erster Linie auf Endothelläsionen als Folge der Dilatation zurück. Die DSA führt 4 h nach dem Eingriff zu einer Aktivierung, Sensibilisierung und in wahrscheinlich sehr geringem Umfang zu einer Anlagerung bzw. verringerten Lebensdauer der Plättchen. PAVK-Patienten im Stadium II nach Fontaine mit kardiovaskulären Risikofaktoren wiesen im Vergleich zu gesunden Probanden eine höhere Relativzahl aktivierter und sensibilisierter Plättchen auf (p = 0,0001). Deshalb vermuten wir, daß präinterventionell aktivierte Plättchen besonders in die Prozesse Aktivierung, Sensibilisierung und Anlagerung involviert bzw. von einer verkürzten Lebensdauer betroffen sind. / Platelet activation plays a crucial role in the pathogenesis of artherosclerosis. Circulating activated platelets are thought to trigger thrombotic events in patients with instable angina pectoris, myocardial infarction and transient ischaemic attacks as well as after coronary angioplasty and surgery. We studied the effect of peripheral arterial disease (PAD) on activation of circulating thrombocytes and evaluated the influence on platelet activation of intraarterial digital subtraction angiography (DSA) and percutaneous transluminal angioplasty (PTA) in the area of the lower extremities. Our study included sixteen control subjects with PAD, twenty-five healthy control subjects and thirty-six patients, fourteen of whom were undergoing DSA, twelve were undergoing PTA and ten we examined during both interventions. Blood samples were obtained from a peripheral vein or from the arterial and venous catheter introducer before and directly and four ours after the procedures. To characterize platelet activation, the expression of activation-dependent platelet antigens (CD62 and CD63) was measured using flow cytometry. Platelet sensibility was analysed by an additional in-vitro-activation. Four hours after DSA, we observed a decrease in activation and an increase in sensibility of thrombocytes in both arterial and venous circulation (p < 0.02), most likely due the contrast medium (CM). We assume, that the relative decrease of platelet activation is caused by a reduced life-time. The relative number of activated thrombocytes decreased in both arterial and venous circulation (p < 0.02) four hours after PTA. Furthermore, we observed reduced amounts of activated platelets in the arterial circulation (p = 0.021) immediately after PTA, in correlation with increased times of dilatation and larger ballon-catheters (p < 0.03). This could be explained by slight migration or shortened life-time of activated thrombocytes. The amount of CM and heparin did not have a pronounced effect. The influence of both interventions on the platelet features and functions seemed to attenuate in the four postinterventional hours. Our results show that angioplasty in peripheral vessels causes activation and presumably slight migration or reduced life-time of circulating thrombocytes immediately and four hours after PTA. We postulate that this is mainly induced by dilatation. DSA was also found to be associated with platelet activation, sensibilisation and presumptive minor migration or shortened life-time of circulating platelets. More activated and sensitized thrombocytes circulated in patients with PAD (clinical stage II according to Fontaine) with cardiovascular risk-factors compared to healthy control subjects (p = 0.001). This supports our assumption that preactivated platelets are particularly involved in activation, sensitizing and migration processes or affected by a reduced life-time.

Made available in DSpace on 2016-04-29T13:17:55Z (GMT). No. of bitstreams: 1 Patricia Nogueira Azevedo.pdf: 3065901 bytes, checksum: 01828ef21534ce60a06f95f4854b6812 (MD5) Previous issue date: 2015-03-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Plan contingencies of reinforcement in the school context involves a number of variables that must be analyzed and taken into account. Therefore, invest in the analysis of contingencies that produce effective teaching that can assist teachers in the exercise of its function becomes essential. This work aimed to investigate the effects of contingencies of positive reinforcement and punishment / negative reinforcement on the answer of children in arithmetic activities. The participants were eight students of 1st and 2nd years of elementary school. To perform the experiment was developed a computer application, with which participants perform arithmetic accounts (addition or subtraction) of two digits, no loan. The participants were divided randomly into four groups of two participants each, which underwent four experimental conditions, two baselines - addition or subtraction operations without reinforcement - and two experimental conditions - Positive Reinforcement with addition operation or Positive Reinforcement with subtraction operation and Negative Reinforcement with addition operation or Negative Reinforcement with subtraction operation. The number of accounts held and the amount of hits and misses of each participant in each session were assessed. The results showed that both contingency positive reinforcement and negative reinforcement can produce changes in the answer of the participants, that is, children learn when subjected to two types of contingencies tested in this study, it is not possible to claim that one produces better results than the other in terms of student learning. There was also an increase in the number of hits as much as the addition of the subtraction operations independently of the contingency effect. Identifies the need for more work to research the relationship between teaching conditions and their products, which can help in the development of new teaching procedures that favor learning / Planejar contingências de reforçamento no contexto escolar envolve uma série de variáveis que devem ser analisadas e levadas em consideração. Para tanto, investir na análise de contingências que produzam ensino efetivo que possa auxiliar professores no exercício de sua função torna-se imprescindível. Este trabalho teve o objetivo de investigar os efeitos de contingências de reforçamento positivo e de punição/reforçamento negativo sobre o responder de crianças em atividades de aritmética. Participaram da pesquisa oito alunos de 1º e 2º anos do ensino fundamental. Para realização do experimento foi desenvolvido um aplicativo de computador, com o qual os participantes realizam contas aritméticas (operações de soma ou subtração) de dois dígitos, sem empréstimo. Os participantes foram divididos, de forma aleatória, em quatro grupos de dois participantes cada, que passaram por quatro condições experimentais, sendo duas linhas de base - Operações de Soma ou Subtração sem reforçamento - e duas condições experimentais - Reforçamento Positivo com Operação de Soma ou Reforçamento Positivo com Operação de Subtração e Reforçamento Negativo com Operação de Soma ou Reforçamento Negativo com Operação de Subtração. Foram avaliadas a quantidade de contas realizadas e a quantidade de acertos e erros de cada participante a cada sessão. Os resultados demonstraram que tanto contingências de reforçamento positivo quanto negativo podem produzir alterações no responder dos participantes, ou seja, as crianças aprendem quando submetidas aos dois tipos de contingências testadas neste estudo, não sendo possível a afirmação de que uma delas produza melhores resultados do que a outra em termos da aprendizagem dos alunos. Verificou-se, também, um aumento no número de acertos tanto nas operações de soma quanto de subtração, independentemente da contingência em efeito. Identifica-se a necessidade de mais trabalhos que pesquisem a relação entre as contingências de ensino e seus produtos, o que pode ajudar no desenvolvimento de novos procedimentos de ensino que favoreçam o aprendizado

A radiografia é uma das ferramentas primárias de auxílio ao diagnóstico e monitoração do tratamento das doenças periodontais. Porém, a análise subjetiva dessas radiografias feita pelo dentista só consegue identificar lesões quando o quadro clínico apresenta perda acima de 30% do conteúdo mineral do osso, levando um sério desafio ao exercício da odontologia. Em muitas situações clínicas, o dentista também precisa ser capaz de quantificar o tamanho de uma lesão para determinar a taxa de progressão ou cura da doença. A técnica de subtração digital de radiografias provê a detecção de mudanças ósseas sutis, de cerca de 5%, levando ao diagnóstico precoce da doença e aumentando assim o sucesso de seu tratamento. Desta forma, o esquema de auxílio ao diagnóstico de reabsorção óssea periodontal através de subtração digital de radiografias odontológicas proposto no presente trabalho emprega a técnica de subtração digital de radiografias, onde duas radiografias odontológicas, tiradas em intervalos de tempos planejados, são subtraídas para obter uma nova imagem onde serão visíveis somente estruturas que mudaram de uma imagem em relação à outra. Será gerada uma imagem que auxiliará o dentista a efetuar um diagnóstico precoce e instituir o melhor plano de tratamento, e assim acompanhar a resposta do tratamento a partir de novas imagens subtraídas. Na fase anterior à subtração, é necessário o alinhamento, para garantir que estruturas idênticas em ambas imagens estejam no mesmo local, e evitando que o resultado da subtração seja errôneo. O alinhamento consiste na marcação de 4 pontos em regiões de alto contraste em ambas as imagens para que a imagem subseqüente seja alinhada em translação e em rotação em relação à primeira. Posteriormente, uma técnica de correção de contraste é utilizada para corrigir eventuais diferenças de contraste. A subtração fornecerá três formas de visualização, na imagem subtraída, da área onde ocorreu uma reabsorção ou ganho ósseo. Uma delas é a subtração qualitativa, cujas áreas onde as imagens se mantiveram idênticas são mostradas em preto, e áreas onde ocorreram mudanças, em branco. A segunda é a subtração quantitativa, que gera a imagem subtraída em níveis de cinza, mostrando em tons de cinza uniformes áreas onde as imagens se mantiveram idênticas; em tons de cinza escuros, onde ocorreu reabsorção óssea; e em tons de cinza claros, onde ocorreu ganho ósseo. Além destas duas subtrações, há uma terceira subtração, a subtração quantitativa porcentagem-colorida, que mostrará a porcentagem de reabsorção ou ganho ósseo através de áreas coloridas na imagem. O intervalo de porcentagens poderá ser escolhido pelo dentista e a este intervalo poderá ser atribuída uma cor para visualização. Intervalos de porcentagens negativas indicam reabsorção óssea e intervalos de porcentagens positivas, ganho ósseo. Os testes realizados encontraram um erro médio de 7,5% no resultado da subtração, sendo que deste total, 3,5% é o erro introduzido pelo digitalizador. É importante ressaltar que esta taxa representa o erro não somente do algoritmo desenvolvido, mas também a propagação do erro em todas as etapas do processo, ou seja, aquisição, digitalização, alinhamento e subtração. Portanto, o erro da subtração deduzido do erro do digitalizador é de somente 4,0%. / Radiography is one of the primary features to help diagnose and monitor the treatment of periodontal diseases. However, the subjective analysis of these radiographs by the dentist only can identify lesions above 30% of mineral bone loss, leading to a serious challenge for the practice of odontology. In many clinical situations, the dentist needs to quantify the size of a lesion to determine the rate of progression or healing the disease. The digital subtraction radiography technique provides the detection of subtle bone changes, i.e., changes of around 5%, leading to an early diagnosis and enlarging the success of its treatment. The aided diagnosis scheme for periodontal bone resorption through odontological digital subtraction radiography proposed in this work employees the digital subtraction radiography technique, where two odontologic radiographs taken at intervals of planned times are subtracted to obtain a new image where only structures that have been changed from one image to the other will be visible. It will generate an image to help the dentist make an early diagnosis and establish the best treatment plan, besides accompanying the treatment’s response starting from new subtracted images. In the stage previous to the subtraction, the lining up is necessary to assure that identical structures on both images are in the same place, avoiding an erroneous result of the subtraction. It consists in marking 4 points in places with high contrast on both images for the subsequent image to be first lined up in translation and then in rotation in relation to the first one. Then, a contrast correction technique is used to correct possible contrast differences. The subtraction will provide three ways of visualization in the subtracted image of the area where a bone resorption or gain occurred. One of them is the qualitative subtraction, where areas kept identical are showed in black and areas where changes occurred are showed white. The second is the quantitative subtraction, which generates a subtracted image in gray levels, showing in uniform gray levels the areas where the images remained identical, in dark gray levels the areas where there was bone resorption and in light gray levels the area with bone gain. The third subtraction is called colored-percentage quantitative subtraction, which shows the percentage of bone resorption or gain through colored areas on the radiograph. The intervals of percentage can be chosen by the dentist and he/she can attribute a color for visualization to this interval. Negative percentage intervals indicate bone resorption and positive percentage intervals correspond to bone gain. The tests performed found a mean error of 7.5% in the result of the subtraction, of which 3.5% correspond to the error introduced by the digitalizer. It is important to stress that this rate represents the error not only for the algorithm developed, but the spreading of the error to all process stages, such as acquisition, digitalization, lining up and subtraction. Therefore, the subtraction error deduced from the digitalizer error is only 4,0%.