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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
451

A Signal Processing Approach to Voltage-Sensitive Dye Optical Imaging / Une approche mathématique de l'imagerie optique par colorant potentiométrique

Raguet, Hugo 22 September 2014 (has links)
L’imagerie optique par colorant potentiométrique est une méthode d’enregistrement de l’activité corticale prometteuse, mais dont le potentiel réel est limité par la présence d’artefacts et d’interférences dans les acquisitions. À partir de modèles existant dans la littérature, nous proposons un modèle génératif du signal basé sur un mélange additif de composantes, chacune contrainte dans une union d’espaces linéaires déterminés par son origine biophysique. Motivés par le problème de séparation de composantes qui en découle, qui est un problème inverse linéaire sous-déterminé, nous développons : (1) des régularisations convexes structurées spatialement, favorisant en particulier des solutions parcimonieuses ; (2) un nouvel algorithme proximal de premier ordre pour minimiser efficacement la fonctionnelle qui en résulte ; (3) des méthodes statistiques de sélection de paramètre basées sur l’estimateur non biaisé du risque de Stein. Nous étudions ces outils dans un cadre général, et discutons leur utilité pour de nombreux domaines des mathématiques appliqués, en particulier pour les problèmes inverses ou de régression en grande dimension. Nous développons par la suite un logiciel de séparation de composantes en présence de bruit, dans un environnement intégré adapté à l’imagerie optique par colorant potentiométrique. Finalement, nous évaluons ce logiciel sur différentes données, synthétiques et réelles, montrant des résultats encourageants quant à la possibilité d’observer des dynamiques corticales complexes. / Voltage-sensitive dye optical imaging is a promising recording modality for the cortical activity, but its practical potential is limited by many artefacts and interferences in the acquisitions. Inspired by existing models in the literature, we propose a generative model of the signal, based on an additive mixtures of components, each one being constrained within an union of linear spaces, determined by its biophysical origin. Motivated by the resulting component separation problem, which is an underdetermined linear inverse problem, we develop: (1) convex, spatially structured regularizations, enforcing in particular sparsity on the solutions; (2) a new rst-order proximal algorithm for minimizing e›ciently the resulting functional; (3) statistical methods for automatic parameters selection, based on Stein’s unbiased risk estimate.We study thosemethods in a general framework, and discuss their potential applications in variouselds of applied mathematics, in particular for large scale inverse problems or regressions. We develop subsequently a soŸware for noisy component separation, in an integrated environment adapted to voltage-sensitive dye optical imaging. Finally, we evaluate this soŸware on dišerent data set, including synthetic and real data, showing encouraging perspectives for the observation of complex cortical dynamics.
452

"Vad håller ni på med?! Sluta slåss!" : En vetenskaplig essä om barns fysiska lekar i förskolans fria lek / “What are you doing?! Stop fighting!” : A scientific essay about children’s physical play in the preschool’s free play

Topolog, Daniel January 2019 (has links)
Denna essä avser att uppnå en djupare förståelse om vad barns fria lek och fysiska lek innebär i förskolan och på vilket sätt fysisk lek bidrar till barns lärande och värdegrundsarbete, genom reflektioner med hjälp av mina erfarenheter och vetenskapliga teorier. Fokus riktas mot barnens inomhuslek. Till denna essä används Lev S Vygotskijs teorier om barns lärande och utveckling samt fantasi och kreativitet. William Corsaros teorier om barns kamratkulturer används för att reflektera över barnens finess i hur de anpassar sig efter förskolans regler. Förutom detta används två lekperspektiv för att fördjupa förståelsen av barns fysiska lek.   Förskolan omfattas av den fria leken där den karakteriseras av att den erbjuder barnen fria val att välja lek, lekkamrater och vilket material som ska användas i leken. Enligt min erfarenhet har jag dock upplevt att fri lek inte är så fri som det låter. Därför kommer jag att undersöka pedagogiska aspekter av den fria leken. Fysisk lek utmanar och väcker pedagogiska frågor och farhågor bland pedagoger i förskolan. Mina reflektioner har fått mig inse att friheten i barns lek är komplext och kräver kritisk reflektion av mitt och andra pedagogers förhållningssätt inför frågor som uppstår vid fysisk lek. Detta har lett mig till förståelsen att fysisk lek har en stämpel som frambringar negativa associationer. Dessa negativa associationer inverkar på hur pedagoger bemöter barn i den fysiska leken. Till exempel frambringar ”bråklek” associationer till allvarligt bråk som leder till konsekvensen att pedagogen avbryter leken. Denna insikt har bidragit till att jag undersökt andra benämningar på fysisk lek vilket fått mig att se vad som sker bortom det som är synligt i barns fysiska lek.    Med nyfikenhet och respekt för barns intresse för att leka fysiska lekar har jag insett hur givande fysiska lekar kan vara för barnen. För att fysiska lekar ska bli givande för barnen behöver pedagogerna ge dem rätta förutsättningar i leken. / This essay intends to achieve a deeper understanding of what children's free play and physical play means in the preschool and in what way physical play contributes to children's learning and value-based work, through reflections using my experiences and scientific theories. The focus is on the children's indoor play. Lev S Vygotsky's theories on children's learning and development as well as imagination and creativity are used for this essay. William Corsaro's theories of children's peer cultures are used to reflect on the children's finesse in how they adapt to the preschool's rules. In addition to this, two play perspectives are used to deepen the understanding of children's physical play. The preschool is embraced by the free play in which it is characterized by the fact that it offers children free choices to choose play, playmates and which material to use in the play. In my experience, however, I have experienced that free play is not as free as it sounds. Therefore, I will examine the educational aspects of free play. Physical play challenges and raises pedagogical issues and concerns among educators in preschool. My reflections have made me realize that freedom in children's play is complex and requires critical reflection of my and other pedagogues’ attitudes to issues that arise during physical play. This has led me to the understanding that physical play has a stamp that gives rise to negative associations. These negative associations affect how educators encounter children in the physical play. For example, gives “play fighting”rise to associations with serious fighting leading to the consequence that the educator interrupts the play. This insight has helped me to see into other names of physical play which made me see what happens beyond what is visiblein children's physical play. With curiosity and respect for children's interest in playing physical play, I have realized how rewarding physical play can be for the children. For physical play to be rewarding for the children, the educators need to give them the right conditions in the play.
453

Papel da via receptor AT1/proteina Gi e da proteína motora miosina IIA no aumento da atividade do NHE3 pela angiotensina II em túbulo proximal renal / Role of the AT1 receptor/Gi protein pathway and the myosin IIA motor protein in the upregulation of NHE3 activity by angiotensin II in the renal proximal tubule

Crajoinas, Renato de Oliveira 25 September 2017 (has links)
A isoforma 3 do trocador Na+ /H+ (NHE3), presente em membrana apical, é a proteína de transporte que medeia a maior parte da reabsorção de NaCl e NaHCO3- em túbulo proximal renal. A fosforilação direta do NHE3 por PKA na serina 552 é um dos mecanismos pelos quais a sua atividade pode ser inibida. A ligação da angiotensina II (Ang II) ao receptor AT1 (AT1R) em túbulo proximal estimula a atividade do NHE3 por diferentes vias de sinalização. Entretanto, não foram ainda bem estabelecidos os efeitos da ativação da via AT1R/Gi, com consequente diminuição nos níveis de cAMP, na regulação do NHE3. A Ang II pode ainda estimular a atividade do NHE3 por promover a sua translocação da base para o corpo das microvilosidades, entretanto, o papel da proteína motora miosina IIA nesta translocação em resposta à Ang II ainda não foi estabelecido. Sendo assim esta tese teve como objetivos: (1) testar a hipótese de que a Ang II diminui os níveis de fosforilação do NHE3 mediados pelo cAMP/PKA na serina 552 aumentando a sua atividade por reduzir os níveis de cAMP e (2) testar a hipótese de que a miosina IIA participa da redistribuição do NHE3 da base para o corpo das microvilosidades em túbulo proximal renal em condições de estímulo da reabsorção de sódio, como ocorre em resposta à Ang II. Visando avaliar os efeitos da ativação da via AT1R/Gi na regulação do NHE3, verificamos, por meio da técnica de recuperação do pH dependente de Na+, que, em condições basais, a Ang II estimulou a atividade do NHE3, mas não alterou a atividade da PKA e nem afetou os níveis de fosforilação do NHE3 na serina 552 em uma linhagem de células de túbulo proximal (OKP). Entretanto, na presença da forskolin (FSK), agente que eleva os níveis intracelulares de cAMP, a Ang II foi capaz de contrapor-se ao efeito inibitório da FSK sobre o NHE3 por promover redução na concentração de cAMP, diminuição da atividade da PKA e, consequentemente, diminuição nos níveis de fosforilação da serina 552. Todos os efeitos da Ang II foram bloqueados quando um pré-tratamento com Losartan, antagonista do receptor AT1, foi feito nas células OKP, destacando a contribuição da via AT1R/proteína Gi no aumento da atividade do NHE3 pela Ang II. Observamos que a inibição da proteína Gi com PTX (toxina pertussis) diminuiu a atividade do NHE3 em células OKP e que a PTX diminuiu a atividade do NHE3 assim como preveniu o efeito estimulatório da Ang II sobre a atividade do NHE3 em túbulo proximal de ratos Wistar. Adicionalmente, com a intenção de avaliar os efeitos da miosina IIA na redistribuição do NHE3, constatamos que a blebistatina, inibidor da miosina IIA, preveniu completamente o aumento de atividade do NHE3 mediado pela Ang II em ratos Wistar e que o uso da blebistatina foi capaz de prevenir o aumento do NHE3 na superfície de células OKP tratadas com Ang II. Em conjunto, nossos resultados sugerem que a Ang II contrapõe-se aos efeitos do cAMP/PKA sobre a fosforilação e a atividade do NHE3 pela ativação da via AT1R/Gi e que a miosina IIA desempenha um papel na mediação da regulação da atividade do NHE3 em túbulo proximal renal de ratos em resposta à Ang II. Sugerem ainda que a desfosforilação do NHE3 na serina 552 pode representar um evento chave na regulação do manuseio de sal tubular proximal pela Ang II na presença de hormônios natriuréticos que promovem o aumento dos níveis de cAMP e da fosforilação do transportador e que a miosina IIA está envolvida na regulação do tráfego do NHE3 em túbulo proximal renal / The Na+/H+ exchanger isoform 3 (NHE3), expressed on the apical membrane, is responsible for most NaCl and NaHCO3 - reabsorption in the renal proximal tubule. Direct phosphorylation of NHE3 by PKA at serine 552 is one of the mechanisms by which its activity is inhibited. Binding of angiotensin II (Ang II) to the AT1 receptor (AT1R) in the proximal tubule stimulates NHE3 activity through multiple signaling pathways. However, the effects of AT1R/Gi activation and subsequent decrease in cAMP accumulation on NHE3 regulation are not well established. Ang II can also stimulate NHE3 activity by promoting its translocations from the base to the body of the microvilli, however, the role of the myosin IIA motor protein in this translocation in response to Ang II is not yet established. Therefore, the aims of this thesis are: (1) to test the hypothesis that Ang II decreases the cAMP/PKA-mediated NHE3 phosphorylation levels at serine 552 increasing its activity by reducing cAMP levels and (2) to test the hypothesis that myosin IIA participates in the NHE3 redistribution from the base to the body of the microvilli in the renal proximal tubule under conditions in which sodium reabsorption is stimulated, such as in response to Ang II. In order to evaluate the effects of AT1R/Gi pathway activation on NHE3 regulation, by means the intracellular pH recovery technique, we verified that under basal conditions, Ang II stimulated NHE3 activity but did not affect PKA-mediated NHE3 phosphorylation at serine 552 in opossum kidney (OKP) cells. However, in the presence of the cAMP-elevating agent forskolin (FSK), Ang II counteracted FSK-induced NHE3 inhibition, reduced intracellular cAMP concentrations, lowered PKA activity, and prevented the FSK-mediated increase in NHE3 serine 552 phosphorylation. All effects of Ang II were blocked by pretreating OKP cells with the AT1R antagonist Losartan, highlighting the contribution of the AT1R/Gi pathway in Ang II-mediated NHE3 upregulation under cAMP-elevating conditions. We also verified that Gi protein inhibition by pertussis toxin treatment decreased NHE3 activity both in vitro and in vivo and, more importantly, prevented the stimulatory effect of Ang II on NHE3 activity in Wistar rat proximal tubules. Additionally, we assessed the effects of myosin IIA on NHE3 redistribution, and found that blebbistatin, a myosin IIA inhibitor, completely prevented the increase of Ang II-mediated NHE3 activity in Wistar rats and that blebbistatin was able to prevent the increase of NHE3 on the Ang II-treated OKP cells surface. Collectively, our results suggest that Ang II counteracts the effects of cAMP/PKA on NHE3 phosphorylation and inhibition by activating the AT1R/Gi pathway and that myosin IIA plays a role in mediating the NHE3 activity regulation in the rat renal proximal tubule in response to Ang II. Furthermore, these findings support the notion that NHE3 dephosphorylation at serine 552 may represent a key event in the regulation of renal proximal tubule sodium handling by Ang II in the presence of natriuretic hormones that promote cAMP accumulation and transporter phosphorylation, and that myosin IIA is involved in NHE3 trafficking regulation in the renal proximal tubule
454

Estudo randomizado da osteossíntese das fraturas da extremidade proximal do úmero com placa ou haste intramedular / Randomized trial on the proximal humerus fracture osteosynthesis with plate or intramedullary nailing

Gracitelli, Mauro Emilio Conforto 10 December 2015 (has links)
INTRODUÇÃO: As fraturas da extremidade proximal do úmero são frequentes, com incidência crescente no idoso e com impacto na qualidade de vida e na função do ombro. Para os casos com desvio, a placa bloqueada é o método mais utilizado de osteossíntese. Bons resultados clínicos são obtidos tanto com a placa bloqueada como com a haste intramedular bloqueada. O objetivo do estudo foi a comparação desses métodos no tratamento das fraturas da extremidade proximal do úmero quanto aos resultados clínicos, radiográficos e à taxa de complicações. MÉTODOS: Nesse estudo clínico prospectivo e randomizado, 72 pacientes com fraturas desviadas da extremidade proximal do úmero, classificadas como em 2 ou 3 partes de Neer, foram alocados para receberem osteossíntese com placa bloqueada (36 pacientes - Grupo Placa) ou haste intramedular bloqueada (36 pacientes - Grupo Haste). Os desfechos clínicos foram avaliados aos 3, 6 e 12 meses e incluíram as escalas de Constant e Murley, Universidade da Califórnia em Los Angeles modificada (UCLA), escala visual analógica de dor (EVA) e o questionário \"Disability of Arm, Shoulder and Hand\"(DASH) e a amplitude de movimento passiva. Os desfechos radiográficos consistiram na avaliação da consolidação e do ângulo cabeça-diáfise. As complicações foram avaliadas até os 12 meses e incluíram a avaliação do manguito rotador pela ultrassonografia. O desfecho primário do estudo foi a avaliação pela escala de Constant e Murley, aos 12 meses de pós-operatório. RESULTADOS: Sessenta e cinco pacientes completaram 12 meses de seguimento, sendo 32 no Grupo Haste e 33 no Grupo Placa. A escala de Constant aos 12 meses foi de 70,3 pontos para o Grupo Haste e de 71,5 pontos para o Grupo Placa (p = 0,750). A escala de Constant Relativa Individual foi de 81% para o Grupo Haste e de 85% para o Grupo Placa (p = 0,400). Também não houve diferença entre os grupos aos 3 e 6 meses para a escala de Constant. A escala EVA e o questionário DASH também não apresentaram diferença aos 3, 6 e 12 meses, assim como os resultados radiográficos. A escala UCLA apresentou diferença de 4,0 pontos aos 3 meses, com melhores resultados para o Grupo Haste (p = 0,005), mas sem diferença significante aos 6 e 12 meses. A amplitude de movimento apresentou diferença de 2,1 pontos favorável ao Grupo Haste para a rotação medial aos 6 meses (p = 0,042), sem diferença para os demais planos de movimento nos diferentes momentos de avaliação. Foram registradas 38 complicações, sendo 28 no Grupo Haste e 10 no Grupo Placa, com diferença estatística (p = 0,001). As complicações ocorreram em 18 pacientes, sendo 11 (34%) do Grupo Haste e sete (21%) do Grupo Placa, sem diferença estatística (p = 0,137). CONCLUSÕES: A osteossíntese das fraturas da extremidade proximal do úmero com placa bloqueada ou haste intramedular bloqueada produziram resultados clínicos e radiográficos semelhantes. A fixação com haste intramedular bloqueada apresentou maior taxa de complicações e reoperações / INTRODUCTION: Fractures of the proximal humerus are common, with an increasing incidence in the elderly and with a high impact on quality of life and shoulder function. For displaced fractures, the locking plate is the most used method of osteosynthesis. Studies have shown good clinical results with the use of locking plates, but also with the fixation with locking intramedullary nail. The aim of this study was to compare the clinical outcomes, radiographic results and the complications between these two methods in patients with displaced proximal humerus fractures. METHODS: In this prospective, randomized clinical trial, 72 patients with displaced fractures of the proximal humerus, classified as Neer 2- or 3-part, were randomly assigned to receive osteosynthesis with either locking plate (36 patients - Plate Group) or locking intramedullary nail (36 patients - Nail Group). The clinical outcomes were evaluated at 3, 6 and 12 months and included the Constant and Murley, University of California at Los Angeles (UCLA) and Disability of Arm, Shoulder and Hand (DASH) scores, visual analog scale (VAS) and the passive range of motion. Radiographic findings (consolidation and head shaft angle) and complications, which included the evaluation of rotator cuff by ultrasound, were also evaluated. The primary outcome was the Constant and Murley score at 12 months. RESULTS: Sixty-five patients completed 12 months of follow-up, 32 in the Nail Group and 33 in the Plate Group. The mean Constant score at 12 months was 70.3 points for the Nail Group and 71.5 points for the Plate Group (p = 0.750) and the mean Relative Constant score was 81% for the Nail Group and 85% points for the Plate Group (p = 0.400). There was also no difference at 3 and 6 months for the Constant score. VAS, DASH and radiographic findings also did not differ at 3, 6 and 12 months. Range of motion showed a 2.1 points difference in favor of the Nail Group for medial rotation at 6 months (p = 0.042), with no difference for the other motions at 3, 6 and 12 months. The UCLA score presented a difference of 4.0 points at 3 months, with better results for the Nail Group (p = 0.005), but no significant difference at 6 and 12 months. Thirty-eight complications were recorded, 28 in the Nail Group and 10 in the Plate Group, with significant difference (p = 0.001). Complications occurred in 18 patients, 11 (34%) of the Nail Group and seven (21%) of the Plate Group, with no significant difference (p = 0.137). CONCLUSIONS: Locking plates and locking intramedullary nail yielded similar clinical and radiographic results. Locking intramedullary nail fixation has a higher risk for complications and reoperations
455

Regulação diferencial do trocador Na+/H+ NHE3 em túbulo proximal renal antes e após o desenvolvimento da hipertensão arterial / Differential regulation of Na+/H+ exchanger NHE3 in renal proximal tubule before and after development of hypertension

Crajoinas, Renato de Oliveira 16 January 2013 (has links)
A hipertensão arterial essencial é caracterizada pela elevação crônica da pressão arterial e representa o principal fator de risco para doenças cardiovasculares e renais. O rim participa do controle da pressão arterial e alterações intrínsecas no manuseio renal de sódio desempenham papel importante na patogênese da hipertensão essencial. Os túbulos proximais renais são responsáveis pela reabsorção da maior parte do sódio filtrado nos glomérulos e a maior parte da reabsorção de sódio neste segmento faz-se através da troca de Na+ por H+ em membrana apical, mediada pela isoforma 3 do trocador Na+/H+ (NHE3). Entretanto, os dados existentes referentes à modulação renal do NHE3 em modelos de hipertensão são ainda conflitantes. Este estudo teve como objetivo avaliar as possíveis alterações funcionais do trocador Na+/H+ NHE3 em túbulo proximal renal na linhagem SHR no estágio de préhipertensão (5 semanas) e de hipertensão (14 semanas) e investigar se estas alterações são acompanhadas de alterações na atividade e na expressão da proteína cinase A (PKA) e de proteínas fosfatase-1 (PP1). Por meio de microperfusão estacionária in vivo mediu-se a atividade do NHE3 em túbulo proximal e verificou-se que a reabsorção de bicarbonato foi reduzida em 62 ± 6 % (P < 0,001) na transição do J-SHR para o A-SHR enquanto foi aumentada em 113 ± 10 % (P < 0,001) na transição entre o J-WKY e o A-WKY. A atividade estimulada do NHE3 em J-SHR é decorrente da redistribuição do NHE3 do domínio intermicrovilar (IMV) para o domínio das microvilosidades (MMV) e do baixo nível de fosforilação da serina 552, sítio consenso para a PKA. Por outro lado, durante a fase de hipertensão, a atividade diminuída do NHE3 deve-se à sua redistribuição para o IMV e ao aumento da fosforilação na serina 552. Para testar a hipótese de que os níveis de fosforilação do NHE3 estariam aumentados em túbulo proximal de SHR adulto devido ao aumento da atividade da PKA e/ou à diminuição na atividade da PP1, foram avaliados tanto os níveis de fosforilação quanto a atividade do NHE3 em SHR jovens e adultos em resposta ao 6MB-cAMP (análogo ao cAMP que ativa especificamente a PKA). O JSHR apresentou um aumento tanto nos níveis de fosforilação da serina 552 (179 ± 14 %, P < 0,001) quanto nos de inibição da atividade (65 ± 10 %, P < 0,001) do NHE3 em relação ao J-SHR em resposta ao 6MB-cAMP. Já no A-SHR, a fosforilação da serina 552 aumentou moderadamente (36 ± 4 %, P < 0,01), assim como inibiu moderadamente (23 ± 9 %, P < 0,05) a atividade do NHE3 em resposta ao 6MBcAMP. Adicionalmente, verificou-se que não houve alteração da atividade da PKA entre os animais nem ao longo da idade e nem entre as linhagens. Por sua vez, o JSHR apresentou maior atividade da PP1 que o A-SHR (1640 ± 107 vs. 940 ± 119 pM/?g, P < 0,01). Além disso, houve uma diminuição na expressão da PP1? no ASHR (32 ± 8 %, P < 0,01) quando comparado ao J-SHR. Os dados sugerem que o NHE3 é diferencialmente regulado antes e após o desenvolvimento da hipertensão em SHR por mecanismos que envolvem modificações pós-transcricionais e distribuição subcelular. Além do mais, a regulação diferencial dos níveis de fosforilação do NHE3 tubular proximal antes e após o desenvolvimento da hipertensão em SHR é devida, provavelmente, a alterações na atividade e na expressão da PP1 / Essential hypertension is characterized by chronic elevation of blood pressure and represents the major risk factor for cardiovascular and renal diseases. The kidney participates in the blood pressure control and intrinsic changes in renal sodium handling play an important role in the pathogenesis of essential hypertension. The renal proximal tubule is responsible for reabsorption of the great majority of sodium that is filtered by the glomerulus and the principal apical membrane mechanism for sodium reabsorption in this nephron is Na+/H+ exchanger isoform 3 (NHE3)- mediated Na+/H+ exchange. However, conflicting data have been reported with regard to NHE3 modulation in experimental models of hypertension. This study aimed to evaluate the possible functional changes of the Na+/H+ exchanger NHE3 in the renal proximal tubule of SHR both at the pre-hypertensive (5 weeks) and at hypertensive (14 weeks) stages and to investigate whether these changes were accompanied by changes in the activity and/or expression of protein kinase A (PKA) and protein phosphatase 1 (PP1). Proximal tubule NHE3 activity was measured by means of stationary microperfusion. Bicarbonate reabsorption was found to be decreased by 62 ± 6 % (P < 0.001) in the transition from youth to adulthood in SHR (Y-SHR to A-SHR), whereas in the transition from Y-WKY to A-WKY it increased by 113 ± 10 % (P < 0.001). Stimulated NHE3 activity in Y-SHR was due to redistribution of NHE3 from intermicrovilar domain (IMV) to microvilar domain (MMV) and to a lower level of serine 552 phosphorylation, a consensus site for PKA. Conversely, during the hypertensive stage, decreased NHE3 activity was due to increased redistribution of NHE3 to the IMV domain and increased phosphorylation at serine 552. To test the hypothesis that the increased levels of NHE3 phosphorylation in the proximal tubule of adult SHR were due to increased PKA activity and/or decreased PP1 activity, it was evaluated both phosphorylation levels and activity of NHE3 in young and adult SHR in response to 6MB-cAMP (an cAMP analog that specifically activates PKA). Y-SHR showed an increase both in the phosphorylation levels at serine 552 (179 ± 14 %, P < 0.001) and in the inhibition of NHE3 transport activity (65 ± 10 %, P < 0.001) compared to Y-SHR in response to 6MB-cAMP. With respect to A-SHR, the phosphorylation of serine 552 was slightly increased (36 ± 4 %, P < 0.01) and NHE3 activity was mildly inhibited (23 ± 9 %, P < 0.05) in response to 6MB-cAMP. Additionally, PKA activity remained unchanged with both age and strain. Nevertheless, Y-SHR exhibited higher PP1 activity than A-SHR (1640 ± 107 vs. 940 ± 119 pM/?g, P < 0.01). Furthermore, PP1? expression was decreased in the renal cortex of A-SHR (32 ± 8 %, P < 0.01) compared to Y-SHR. Taken together, these data suggest that NHE3 is differentially regulated before and after development of hypertension in SHR by mechanisms involving post-translational modifications and subcellular distribution. Moreover, the differential regulation of proximal tubule NHE3 phosphorylation levels before and after development of hypertension in SHR is most likely due to changes on the activity and expression of PP1
456

Développement de méthodes pour l'évaluation de la rigidité aortique en IRM : mesure de la distensibilité et de la vitesse d'onde de pouls / Evaluation of the oartic stiffness in MRI : assesment of the distensibility and the pulse wave velocity

Dogui, Anas 11 February 2011 (has links)
Elle peut être estimée par deux indices : la distensibilité de la paroi aortique et la vitessede propagation de l'onde de pouls (VOP) le long de l'artère. Ces marqueurs peuvent êtreobtenus dans l'aorte proximale grâce à l'imagerie de résonance magnétique (IRM) et sontreliés entre eux par le modèle de Bramwell-Hill. L'objectif de cette thèse est, d'une part, deproposer et de valider cliniquement des méthodes d'estimation de la distensibilité et de laVOP aortique, et, d'autre part, d'étudier le modèle théorique de Bramwell-Hill, au regarddes données cliniques. Nous avons dans un premier temps comparé différentes méthodesd'estimation de la distensibilité de l'aorte. Cette étude a permis d'identifier l'approche quifournit la meilleure description physiologique de l'aorte ascendante et descendante. Ensuite,nous avons proposé une nouvelle méthode de mesure de la VOP proximale. Celle-cia été validée par comparaison avec les méthodes proposées dans la littérature en termesde reproductibilité et de corrélations des mesures avec : 1) l'âge : facteur de risque "naturel " de la rigidité aortique chez des sujets sains, et 2) la VOP carotido-fémoralemesurée par tonométrie, méthode de référence utilisée en routine clinique pour estimer larigidité globale de l'aorte. Enfin, nous avons validé le modèle théorique de Bramwell-Hillau niveau des sections de l'aorte ascendante et descendante. En conclusion, nous avonsproposé des approches locale et régionale d'évaluation de la rigidité de l'aorte proximaleet nous en avons validé la robustesse, notamment dans le cadre du vieillissement artériel. / The aortic stiffness is recognized as a major factor of cardiovascular risk, and is characterizedby distensibility and pulse wave velocity (PWV) measurements. These aorticindices are related according to the Bramwell-Hill model and can be assessed in the proximalaorta with magnetic resonance imaging (MRI). The aims of this thesis were : 1) topropose and validate clinical methods for estimating the distensibility and aortic PWVfrom MRI data, and 2) to study the theoretical model of Bramwell-Hill in the light ofclinical data. First, we compared different methods for estimating the distensibility ofthe aorta. This study permitted to identify the approach which provides the best physiologicaldescription of the ascending and descending aorta. Then we proposed a newmethod for estimating the PWV in the proximal aorta, which was validated by comparisonwith previously described methods in terms of reproducibility and correlation ofaortic PWV with : 1) age : major risk factor of aortic stiffness in healthy subjects, and 2)carotid-femoral PWV measured by tonometry, gold standard method in clinical routinefor estimating the overall stiffness of the aorta. Finally, we validated the theoretical modelof Bramwell-Hill at the sections of the ascending and descending aorta. In conclusion, weproposed local and regional approaches to assess the stiffness of the proximal aorta, andwe validated its robustness, particularly in the context of aging.
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Estudo randomizado da osteossíntese das fraturas da extremidade proximal do úmero com placa ou haste intramedular / Randomized trial on the proximal humerus fracture osteosynthesis with plate or intramedullary nailing

Mauro Emilio Conforto Gracitelli 10 December 2015 (has links)
INTRODUÇÃO: As fraturas da extremidade proximal do úmero são frequentes, com incidência crescente no idoso e com impacto na qualidade de vida e na função do ombro. Para os casos com desvio, a placa bloqueada é o método mais utilizado de osteossíntese. Bons resultados clínicos são obtidos tanto com a placa bloqueada como com a haste intramedular bloqueada. O objetivo do estudo foi a comparação desses métodos no tratamento das fraturas da extremidade proximal do úmero quanto aos resultados clínicos, radiográficos e à taxa de complicações. MÉTODOS: Nesse estudo clínico prospectivo e randomizado, 72 pacientes com fraturas desviadas da extremidade proximal do úmero, classificadas como em 2 ou 3 partes de Neer, foram alocados para receberem osteossíntese com placa bloqueada (36 pacientes - Grupo Placa) ou haste intramedular bloqueada (36 pacientes - Grupo Haste). Os desfechos clínicos foram avaliados aos 3, 6 e 12 meses e incluíram as escalas de Constant e Murley, Universidade da Califórnia em Los Angeles modificada (UCLA), escala visual analógica de dor (EVA) e o questionário \"Disability of Arm, Shoulder and Hand\"(DASH) e a amplitude de movimento passiva. Os desfechos radiográficos consistiram na avaliação da consolidação e do ângulo cabeça-diáfise. As complicações foram avaliadas até os 12 meses e incluíram a avaliação do manguito rotador pela ultrassonografia. O desfecho primário do estudo foi a avaliação pela escala de Constant e Murley, aos 12 meses de pós-operatório. RESULTADOS: Sessenta e cinco pacientes completaram 12 meses de seguimento, sendo 32 no Grupo Haste e 33 no Grupo Placa. A escala de Constant aos 12 meses foi de 70,3 pontos para o Grupo Haste e de 71,5 pontos para o Grupo Placa (p = 0,750). A escala de Constant Relativa Individual foi de 81% para o Grupo Haste e de 85% para o Grupo Placa (p = 0,400). Também não houve diferença entre os grupos aos 3 e 6 meses para a escala de Constant. A escala EVA e o questionário DASH também não apresentaram diferença aos 3, 6 e 12 meses, assim como os resultados radiográficos. A escala UCLA apresentou diferença de 4,0 pontos aos 3 meses, com melhores resultados para o Grupo Haste (p = 0,005), mas sem diferença significante aos 6 e 12 meses. A amplitude de movimento apresentou diferença de 2,1 pontos favorável ao Grupo Haste para a rotação medial aos 6 meses (p = 0,042), sem diferença para os demais planos de movimento nos diferentes momentos de avaliação. Foram registradas 38 complicações, sendo 28 no Grupo Haste e 10 no Grupo Placa, com diferença estatística (p = 0,001). As complicações ocorreram em 18 pacientes, sendo 11 (34%) do Grupo Haste e sete (21%) do Grupo Placa, sem diferença estatística (p = 0,137). CONCLUSÕES: A osteossíntese das fraturas da extremidade proximal do úmero com placa bloqueada ou haste intramedular bloqueada produziram resultados clínicos e radiográficos semelhantes. A fixação com haste intramedular bloqueada apresentou maior taxa de complicações e reoperações / INTRODUCTION: Fractures of the proximal humerus are common, with an increasing incidence in the elderly and with a high impact on quality of life and shoulder function. For displaced fractures, the locking plate is the most used method of osteosynthesis. Studies have shown good clinical results with the use of locking plates, but also with the fixation with locking intramedullary nail. The aim of this study was to compare the clinical outcomes, radiographic results and the complications between these two methods in patients with displaced proximal humerus fractures. METHODS: In this prospective, randomized clinical trial, 72 patients with displaced fractures of the proximal humerus, classified as Neer 2- or 3-part, were randomly assigned to receive osteosynthesis with either locking plate (36 patients - Plate Group) or locking intramedullary nail (36 patients - Nail Group). The clinical outcomes were evaluated at 3, 6 and 12 months and included the Constant and Murley, University of California at Los Angeles (UCLA) and Disability of Arm, Shoulder and Hand (DASH) scores, visual analog scale (VAS) and the passive range of motion. Radiographic findings (consolidation and head shaft angle) and complications, which included the evaluation of rotator cuff by ultrasound, were also evaluated. The primary outcome was the Constant and Murley score at 12 months. RESULTS: Sixty-five patients completed 12 months of follow-up, 32 in the Nail Group and 33 in the Plate Group. The mean Constant score at 12 months was 70.3 points for the Nail Group and 71.5 points for the Plate Group (p = 0.750) and the mean Relative Constant score was 81% for the Nail Group and 85% points for the Plate Group (p = 0.400). There was also no difference at 3 and 6 months for the Constant score. VAS, DASH and radiographic findings also did not differ at 3, 6 and 12 months. Range of motion showed a 2.1 points difference in favor of the Nail Group for medial rotation at 6 months (p = 0.042), with no difference for the other motions at 3, 6 and 12 months. The UCLA score presented a difference of 4.0 points at 3 months, with better results for the Nail Group (p = 0.005), but no significant difference at 6 and 12 months. Thirty-eight complications were recorded, 28 in the Nail Group and 10 in the Plate Group, with significant difference (p = 0.001). Complications occurred in 18 patients, 11 (34%) of the Nail Group and seven (21%) of the Plate Group, with no significant difference (p = 0.137). CONCLUSIONS: Locking plates and locking intramedullary nail yielded similar clinical and radiographic results. Locking intramedullary nail fixation has a higher risk for complications and reoperations
458

Tier 2 Interventions for Students in Grades 1-3 Identified as At-Risk in Reading

Ray, Jennifer S. 01 January 2017 (has links)
The majority of Grade 4 students in the United States do not read at the proficient level. In response to this problem, which has persisted for decades, the United States Congress in 2004 mandated response to intervention as a multitiered classroom support system designed to improve reading skills for students in K-12 public schools. However, little research has been conducted about how classroom teachers use diagnostic assessments, provide small group instruction, and monitor progress in reading interventions. The purpose of this qualitative study was to examine how teachers used assessments and instruction in reading interventions for students in Grades 1-3 who were at-risk in reading. The conceptual framework was based on Vygotsky's theory of cognitive development related to the zone of proximal development. A single case study design was used to collect data from multiple sources, including teacher interviews, observations of interventions in reading, and related documents. Participants included 3 teachers in Grades 1-3 from an elementary school located in a western state. Data analysis involved coding and constructing categories for each data source and examining categorized data for themes and discrepancies. Results showed that teachers in Grades 1-3 used various diagnostic assessments and classroom observations to place students at-risk in reading in interventions, and they also used various diagnostic, formative, and summative assessments to inform their instruction. In addition, participants used a scaffolding process that involved contingency, fading, and transfer of responsibility to provide instruction for these students. This research contributes to positive social change by advancing knowledge about how to improve reading intervention instruction so that students at-risk in reading may better contribute to society as literate citizens.
459

Conception et évaluation d'un dispositif d'imagerie multispectrale de proxidétection embarqué pour caractériser le feuillage de la vigne / "On-the-go" multispectral imaging system embedded on a track laying tractor to characterize the vine foliage

Bourgeon, Marie-Aure 30 October 2015 (has links)
En Viticulture de Précision, l’imagerie multi-spectrale est principalement utilisée pour des dispositifs de télédétection. Ce manuscrit s’intéresse à son utilisation en proxidétection, pour la caractérisation du feuillage. Il présente un dispositif expérimental terrestre mobile composé d’un GPS, d’une caméra multi-spectrale acquérant des images visible et proche infrarouge, et d’un Greenseeker RT-100 mesurant l’indice Normalized Difference Vegetation Index (NDVI). Ce système observe le feuillage de la vigne dans le plan de palissage, en lumière naturelle. La parcelle étudiée comporte trois cépages (Pinot Noir, Chardonnay et Meunier) plantés en carré latin. En 2013, six jeux de données ont été acquis à différents stades phénologiques.Pour accéder aux propriétés spectrales de la végétation, il est nécessaire de calibrer les images en réflectance. Cela requiert l’utilisation d’une mire de MacBeth comme référence radiométrique. Lorsque la mire est cachée par les feuilles, les paramètres de calibration sont estimés par une interpolation linéaire en fonction des images les plus proches sur lesquelles la mire est visible. La cohérence de la méthode d’estimation employée est vérifiée par une validation croisée (LOOCV).La comparaison du NDVI fournie par le Greenseeker avec celui déterminé via les images corrigées permet de valider les données générées par le dispositif. La polyvalence du système est évaluée via les images où plusieurs indices de végétation sont déterminés. Ils permettant des suivis de croissance de la végétation originaux offrant des potentialités de phénotypage ou une caractérisation de l’état sanitaire de la végétation illustrant la polyvalence et le gain en précision de cette technique. / Mutispectral imaging systems are widely used in remote sensing for Precision Viticulture. In this work, this technique was applied in the proximal sensing context to characterize vine foliage. A mobile terrestrial experimental system is presented, composed of a GPS receiver, a multi-spectral camera acquiring visible and near infrared images, and a Greenseeker RT-100 which measures the Normalized Difference Vegetative Index (NDVI). This optical system observes vine foliage in the trellis plan, in natural sunlight. The experimental field is planted with Chardonnay, Pinot Noir and Meunier cultivars in a latin squared pattern. In 2013, six datasets were acquired at various phenological stages.Spectral properties of the vegetation are accessible on images when they are calibrated in reflectance. This step requires the use of a MacBeth colorchart as a radiometric reference. When the chart is hidden by leaves, the calibration parameters are estimated by simple linear interpolation using the results from resembling images, which have a visible chart. The performance of this method is verified with a cross-validation technique (LOOCV).To validate the data provided by the experimental system, the NDVI given by the Greenseeker was compared to those computed from the calibrated images. The assessment of the versatility of the system is done with the images where several indices were determined. It allows an innovative follow-up of the vegetative growth, and offering phenotyping applications. Moreover, the characterization of the sanitary state of the foliage prove that this technique is versatile and accurate.
460

Etude des composés phénoliques impliqués dans la réponse des feuilles de vigne au mildiou

Bellow, Sébastien 08 June 2012 (has links) (PDF)
Maîtriser l'impact des maladies sur les cultures est un défi majeur de l'agriculture moderne. Cette préoccupation est un aspect important de l'optimisation de la productivité, notamment en viticulture. En France, le mildiou de la vigne causé par Plasmopara viticola est une des maladies cryptogamiques responsable des épidémies les plus dévastatrices et les plus redoutées. Les traitements reposent sur l'utilisation préventive, systématique et onéreuse de composés chimiques antifongiques dont l'utilisation massive constitue un risque à la fois pour l'homme et l'environnement. La réduction de l'utilisation de fongicide implique le développement d'outils de diagnostic au champ, qui requiert la compréhension des interactions entre la plante et les agents pathogènes. Les travaux de cette thèse pluridisciplinaire ont porté sur le pathosystème Plasmopara viticola - Vitis vinifera, notamment pour répondre à l'intérêt croissant pour un outil de diagnostic en temps réel de la maladie utilisable au vignoble. Les stilbènes sont des phytoalexines impliqués dans la défense de certaines plantes supérieures vis-à-vis de stress biotiques et abiotiques. L'autofluorescence de ces composés phénoliques, dont la biosynthèse est induite dans les feuilles de vigne par P. viticola, en fait un potentiel marqueur naturel de l'infection. En effet, la faible autofluorescence bleu-verte des feuilles de vigne saines est considérablement renforcée par l'autofluorescence violet-bleue des stilbènes à la surface de feuilles de vigne infectée par P. viticola. Cette étude a montré que quelque soit le niveau de résistance du génotype, l'autofluorescence violet-bleue des stilbènes induit par l'infection est présente au niveau des parois des cellules de l'épiderme. En dehors de la concentration, la viscosité s'est révélé être la principale variable physico-chimique influençant l'intensité de l'autofluorescence des stilbènes dans les différents compartiments cellulaires des feuilles de vigne. Ceci explique la fluorescence intense des parois, particulièrement rigides, des cellules de garde (stomates) des feuilles infectées. Le suivi cinétique journalier a révélé la nature transitoire de l'autofluorescence des stilbènes lors de l'infection. La robustesse et l'intérêt de ce signal a également été validée par la mesure à différentes échelles (de la cellule à la feuille entière) et avec différentes méthodes fluorimétriques. Les résultats de ce travail ont permis des avancées sur la connaissance du rôle de composés phénoliques induits et constitutifs dans la défense contre P. viticola. En plus de la localisation de l'autofluorescence des stilbènes en surface des feuilles, la microscopie confocale couplée à la microspectrofluorimetrie a révélé différentes localisations de ces phytoalexines dans la profondeur des tissus en corrélation avec le niveau de résistance des génotypes. L'utilisation de l'autofluorescence des stilbènes comme marqueur de l'infection a permis de mettre en évidence : 1) le fait que les flavonols constitutifs des feuilles de V. vinifera retardent le développement de l'infection par P. viticola; et 2) le fait que les acides hydroxycinnamiques constitutifs ne semble pas participer à la défense contre P. viticola. Enfin, une nouvelle méthode de diagnostic non-destructive du mildiou sur feuille basée sur l'autofluorescence des stilbènes a été développée. Elle a montré une détection pré-symptomatique du mildiou sur les feuilles de vigne entières dès le premier jour après l'infection sur la face abaxiale et le troisième jour sur la face adaxiale. Cette méthode de diagnostic du mildiou a été validée au laboratoire notamment grâce à un prototype de capteur proximal développé en collaboration avec la société Force-A. La validation de la méthode au vignoble dans le cadre d'infection naturelle est la prochaine étape pour une utilisation de ce capteur optique dans le cadre de l'agriculture durable et de la sélection variétale.

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