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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.
131

Influência do exercício sobre a resposta imunológica de ratos desnutridos. / Influence on the physical exercise on the immunological response of undenourished rats.

Cunha, Wilton Darleans dos Santos 13 August 2009 (has links)
A desnutrição é capaz de induzir diversas alterações metabólicas afetando marcadamente a composição corporal e o sistema imunológico. O exercício físico, por sua vez, produz alterações no organismo para uma melhor capacidade de adaptação a situações de estresse. O desvio da situação de homeostase produzida pelo exercício físico induz uma reorganização de seus mecanismos funcionais, principalmente dos mecanismos endócrinos e imunológicos. Ainda é pouco conhecida a influência do exercício sobre a desnutrição e também as conseqüências sobre o sistema imunológico quando as duas variáveis são combinadas. Assim, esse trabalho teve como objetivo avaliar os efeitos do exercício físico de endurance sobre ratos submetidos a um protocolo de desnutrição crônica. Avaliamos ratos Wistar machos, desnutridos por 16 semanas, divididos em 4 grupos: eutrófico sedentário (ES), eutrófico treinado (ET), desnutrido sedentário (DS), desnutrido treinado (DT). O treinamento físico foi realizado em esteira, por 10 semanas, 5 vezes por semana, com intensidade aproximada de 60- 65% do consumo máximo de oxigênio. Avaliou-se a composição corporal, através da aferição do peso corporal, peso dos tecidos muscular esquelético e adiposo, do fígado, do conteúdo de gordura e proteína na carcaça, e a concentração de leptina, ACTH, glicose, insulina, e glutamina no plasma. Avaliamos também, através de citometria de fluxo, os marcadores de superfície celular CD3 e CD4, bem como a celularidade no timo. O consumo máximo de oxigênio e o desempenho através de um teste até a exaustão também foram analisados. A análise estatística utilizada foi o teste de variância ANOVA two-way com pós teste de Bonferroni e, nível de significância adotado de p<0,05. Os resultados encontrados demonstraram que o treinamento de endurance em ratos submetidos à desnutrição crônica promoveu uma acentuada redução do peso e da adiposidade corporal; um aumento da massa muscular relativa ao peso corporal; um restabelecimento da glicemia aos valores normais; uma melhor relação da concentração insulina/glicose, sugerindo uma sensibilidade à insulina aumentada; um aumento dos estoques de glicogênio muscular; um maior consumo máximo de oxigênio; e uma recuperação na morfologia e fisiologia tímica, uma maior resposta proliferativa do baço e linfonodos estimulados com IL2. Concluímos desta forma que o exercício foi capaz de recuperar a morfologia, como também a maturação timócitos CD3 e CD4 e sua celuraridade em ratos desnutridos. A resposta proliferativa à estimulação da IL2 também foi recuperada. / Malnutrition is capable of inducing diverse metabolic alterations, markedly affecting body composition and the immune system. Physical exercise, on the other hand, induces a renders the organism more capable of adaptation to stress. Still, little is known about the influence of exercise training upon malnutrition-related alterations and its consequences on the immune system. Our aim was to evaluate the effect of moderate intensity exercise training in rats submitted to a protocol (16wk) of chronic malnutrition. Male Wistar rats were divided in to 4 groups: sedentary, fed ad libitum (SF); trained fed ad libitum (TF); sedentary energy restricted (RES); and trained energy restricted (TER). Training was carried out on a treadmill for 10 weeks, 5 time wk, under an intensity of 60-65% of the maximal oxygen consumption. We evaluated the Corporal composition, the variation of body weight, and the weight of the skeletal muscle, adipose tissues, and liver; as well as fat and protein content in the carcass; and also plasma leptin, ACTH, glucose, insulin and glutamine concentration. We also examined through flow cytometry CD3 and CD4, as well as the celularity in the thymus. The maximum consumption of oxygen and the performance were also assessed. The results demonstrate that endurance training in rats submitted to the chronic malnutrition protocol promoted reduction of body weight and of corporal adiposity; an increase in the relative contribution of muscle to body weight; the reestablishment of glicemia; improval of insulin/glucose reason, suggesting increased sensitivy to insulin; an increase of muscle glycogen content; enhanced oxygen consumption; are recovery of the morphology and physiology of the thymus, together with a proliferative response of the spleen and lymph nodes stimulated with IL2. We conclude in such a way that moderate intensity training restored thymus morphology and the capacity of maturation of CD3 and CD4 and also timocyte number and the of proliferative response to IL2 stimulation.
132

Efeitos agudos de diferentes intensidades do exercício aeróbio na resposta hipotensora pós-exercício em pessoas com Síndrome de Down

Bezerra, Maria Edilma da Silva 02 March 2018 (has links)
Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-08-08T14:40:53Z No. of bitstreams: 1 MariaEdilmadaSilvaBezerraDissertacao2018.pdf: 1352574 bytes, checksum: 329c4e9b5bb3df4f0c7059f59c9e1648 (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-08-08T14:41:04Z (GMT) No. of bitstreams: 1 MariaEdilmadaSilvaBezerraDissertacao2018.pdf: 1352574 bytes, checksum: 329c4e9b5bb3df4f0c7059f59c9e1648 (MD5) / Made available in DSpace on 2018-08-08T14:41:04Z (GMT). No. of bitstreams: 1 MariaEdilmadaSilvaBezerraDissertacao2018.pdf: 1352574 bytes, checksum: 329c4e9b5bb3df4f0c7059f59c9e1648 (MD5) Previous issue date: 2018-03-02 / Studies have shown that even a single session of physical exercise lowers blood pressure after its completion. This phenomenon is called post-exercise hypotension (PEH), and has been considered as a non-pharmacological way to control blood pressure. However, there are no studies regarding the occurrence of PEH after acute exercise in individuals with Down Syndrome (DS). This study aimed to analyze the occurrence of PEH in these individuals and the possible role of exercise intensity. Ten individuals with DS, of both genders, participated in the study (age, 29 ± 7 years, body mass, 60.7 ± 9 kg, height, 1.48 ± 0.11 cm and BMI, 27.6 ± 2.4 kg/m²). Volunteers randomly underwent two sessions of exercise on a stationary bike for 20 minutes and a sham control session. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured after 15 minutes of resting, at the 20th minute of each exercise session or control, and at 15th, 30th and 45th minutes of post-exercise recovery. Both moderate and intense exercise performed acutely increased SBP (p<0.001; p<0.01, respectively) with no effect on DPB levels in individuals with DS. However, neither the moderate nor the intense exercise were enough to elicit PEH. The results indicated that individuals with DS may not present PEH for the intensities, duration and exercise mode as applied in the present investigation. While additional studies with different exercise strategies are needed, our findings contribute to the body of literature regarding the PEH responses in adults with DS. / Estudos demonstraram que mesmo em uma única sessão de exercício físico há a redução da pressão arterial após sua realização. Este fenômeno é chamado de hipotensão pós-exercício (HPE) e foi considerado como uma forma não farmacológica de controlar a pressão arterial. No entanto, não há estudos sobre a ocorrência de HPE após o exercício agudo em indivíduos com síndrome de Down (SD). Este estudo teve como objetivo analisar a ocorrência de HPE nesses indivíduos e o possível papel da intensidade do exercício. Participaram do estudo: dez indivíduos com SD, 7 do sexo masculino e 3 do feminino, (idade, 29 ± 7 anos, massa corporal, 60,7 ± 9 kg, altura, 1,48 ± 0,11 cm e IMC, 27,6 ± 2,4 kg / m²). Os voluntários passaram, aleatoriamente, por duas sessões de exercício em uma bicicleta estacionária, por 20 minutos, e uma sessão de controle simulada. A frequência cardíaca (FC), pressão arterial sistólica (PAS) e a pressão arterial diastólica (PAD) foram medidas após 15 minutos de repouso, no vigésimo minuto de cada sessão de exercício ou controle, e aos 15, 30 e 45 minutos do pós-exercício recuperação. Os exercícios moderados e intensos provocaram um aumento agudo da PAS (p <0,001; p <0,01, respectivamente) sem efeito nos níveis de PAD em indivíduos com SD. No entanto, nem o exercício moderado nem o exercício intenso foram suficientes para provocar HPE. Os resultados indicaram que indivíduos com SD não apresentaram HPE para as intensidades, duração e modo de exercícios aplicados na presente investigação. Embora sejam necessários estudos adicionais com diferentes estratégias de exercícios, nossos resultados contribuem para o corpo da literatura em relação às respostas de HPE em adultos com SD.
133

Analysis of Scottish health survey data to inform Scottish physical activity and sedentary behaviour policy and surveillance

Strain, Tessa Rosalind January 2018 (has links)
In 2011, the United Kingdom (U.K.) physical activity (PA) guidelines were updated. The adult moderate-to-vigorous intensity PA (MVPA) recommendation changed to reflect that different frequency and intensity permutations lead to equivalent health benefits. New recommendations were added for muscle strengthening activities (MSA) and the reduction of sedentary time (ST). Those over 65 years were also recommended to undertake balance and co-ordination activities (BCA). Despite these new additions, Scottish PA policy still concentrated on MVPA, with considerable resources allocated to sport and some exercise activities. Since 2012, the Scottish Health Survey (SHeS) has collected data relating to these new recommendations annually, but few analyses have been undertaken. This thesis contains the most comprehensive analyses of the 2012-15 SHeS PA and ST data to date, and a review into whether the method produces valid and reliable estimates. The aim of this thesis was to inform Scottish PA and sedentary behaviour policy by producing research to support the incorporation of these new recommendations and the promotion of non-sport-related MVPA policies. It also aimed to inform any future developments to PA and ST surveillance in Scotland. The first three studies of this thesis are cross-sectional analyses of the updated recommendations for adults in Scotland. They present prevalence and participation data in specific domains, activities, and behaviours by age and sex. The main findings were that (1) sport was a minority contributor to the total MVPA of adults in Scotland, regardless of sex, age, or activity status (never more than 20%), (2) compliance with the MSA recommendation was approximately half that of the MVPA recommendation (31% of men and 24% of women), and compliance with the BCA recommendation amongst those over 65 years was very low (19% of older men and 12% of older women), and (3) middle-aged adults in work reported a comparable amount of weekday ST to adults over 75 years (7-8 hours per day). The fourth study was a review of the available evidence into whether the PA and ST estimates produced by the 2012-15 SHeS were valid and reliable. The SHeS was found to be fit for purpose, but recommendations were made regarding the analysis and interpretation of the data to minimise areas of concern. These were (1) analyse MVPA data with and without the domain of occupational MVPA, (2) make it clear that only sport and exercise activities can contribute to achieving the MSA and BCA recommendations under the SHeS method, and (3) focus on the comparisons between groups in relation to ST, rather than on the absolute values. The fifth study used the findings from the previous four to inform the design of a prospective cohort study that will investigate the joint effects of MVPA and total ST on all-cause mortality, cardiovascular disease, cancer, and diabetes. This thesis contains the results of the preliminary analyses. This study is designed to inform policy by providing novel information on how the combination of these behaviours affects health outcomes in a representative sample of Scottish adults. There is clear evidence that this work has already informed policy and surveillance. The work on the relative contribution of the domains of MVPA is regularly cited in evidence briefings for the Scottish Government and the Scottish Parliament. This has increased the awareness amongst key policy-makers that sport is not a major contributor to the total MVPA of adults in Scotland. The work on MSA, BCA, and ST was a catalyst for a proposal to include indicators relating to these recommendations on the national PA monitoring framework. The work on MSA and BCA has also been a key reference text in preparation for the next update to the U.K. PA guidelines, stressing the need to consider surveillance at an early stage. In summary, the novel analyses of SHeS data undertaken for this thesis have demonstrably informed PA and sedentary behaviour policy and surveillance in Scotland.
134

Sobrecarga moderada de ferro em ratos: interação com frutanos e/ou fitato no metabolismo hepático e ósseo / Moderate iron overload in rats: interaction with fructans and/or phytate in hepatic and bone metabolism

Cocato, Maria Lucia 06 October 2008 (has links)
O excesso de Fe no organismo gera espécies reativas de oxigênio (ERO) que são potencialmente tóxicas. Entretanto, a magnitude dos efeitos da exposição à moderada sobrecarga de Fe e da sua interação com facilitadores e/ou inibidores da absorção mineral não é conhecida. O objetivo deste trabalho foi avaliar esses efeitos e a sua interação com fruta nos e/ou fitato (facilitadores e inibidores da absorção de Fe, respectivamente) nos índices séricos do estado nutricional em Fe, no perfil dos lipídeos séricos e em parâmetros do metabolismo hepático e ósseo. Para o experimento foram utilizados 34 ratos machos Wistar, pesando inicialmente 49,3 ± 3,9g, alojados individualmente em gaiolas de aço semimetabólicas por 92 dias. Uma dieta AIN-93G (Dieta 1: Grupo Controle) e quatro dietas AIN93G modificadas foram usadas para o estudo, com as seguintes características: Dieta 2: sobrecarga moderada de ferro com 550mgFe/kg de ração (Grupo SBC); Dieta 3: sobrecarga moderada de ferro + 18% de farinha de yacon (Grupo SBC+FY); Dieta 4: sobrecarga moderada de ferro + 0,6% de fitato (Grupo SBC+FIT); Dieta 5: sobrecarga moderada de ferro + 18% de farinha de yacon + 0,6 % de fitato (Grupo SBC+FY+FIT). Os resultados demonstraram que a moderada sobrecarga de Fe ou a sua interação com farinha de yacon e/ou fitato não alterou os índices séricos do estado nutricional em Fe. Ocorreu aumento na atividade sérica da AST apenas no grupo SBC (p=0,055). Nos grupos SBC e SBC+FY houve diminuição na concentração do colesterol sérico (p=0,002) e, apenas no grupo SBC+FY+FIT, diminuição da concentração sérica do VLDL. No fígado, houve aumento significativo (p=0,002) da concentração de Fe não-heme nos grupos IO (+83%) e SBC+FIT (+117%) e, em todos os grupos SBC, na atividade da enzima GPx (p=0,000). A atividade da CAT foi menor (p=0,036) apenas para o grupo SBC+FY+FIT. Em todos os grupos SBC ocorreu significativo aumento nos depósitos de hemossiderina em torno das células de Kupffer (p=0,000). Houve aumento na apoptose em todos os grupos SBC, com os grupos SBC+FY e SBC+FY +FIT apresentando o maior número de corpúsculos apoptóticos/área (+405% e +342%, respectivamente) (p=0,000). Não houve alteração nos parâmetros relacionados ao metabolismo ósseo. No grupo SBC+FY houve significativo aumento na absorção aparente de Ca (p<0,05). Conclusões: A moderada sobrecarga de Fe não alterou os índices séricos do estado nutricional em Fe, mas resultou em alterações no tecido hepático e no perfil dos lipídeos séricos. Com exceção do perfil de lipídeos séricos, no qual apenas o fitato pareceu exercer efeito protetor, nos demais parâmetros avaliados a interação com farinha de yacon rica em fruta nos e/ou fitato reverteu parcial ou totalmente as alterações induzidas pela moderada sobrecarga de Fe. / Excess Fe in the organism generates potentially toxic reactive oxygen species (ROS). However, the magnitude of the effects of a moderate Fe overload and its interaction with factors which inhibit or facilitate mineral absorption is not known. The aim of the present work was to evaluate such effects and their interaction with fructans and/or phytate (compounds which facilitate and inhibit Fe absorption, respectively) on serum iron status indices, on the profile of serum lipids and on hepatic and bone metabolism parameters. In the experiment, thirty-four male Wistar rats initially weighing 49,3 ± 3,9g were used. The rats were housed in individual stainless-steel wire-mesh cages for 92 days. An AIN-93G diet (Diet 1: Control Group) and four modified AIN-93G diets were used in the study. The modified diets presented the following formulations: Diet 2: moderate Fe overload with 550mgFe/kg diet (IO Group); Diet 3: moderate Fe overload + 18% yacon flour (IO-YF Group); Diet 4: moderate Fe verload + 0.6% phytate (IO-Phy Group); Diet 5: moderate Fe overload + 18% yacon flour + 0.6% phytate (IO-YF-Phy Group). The results demonstrated that a moderate Fe overload or its interaction with yacon flour and/or phytate did not alter the serum iron status indices. An increase in the serum AST activity was observed only in the IO group (p=0,055). In the IO and IO-YF groups, there was a reduction in the serum cholesterol concentration (p=0,002) and a reduction in the serum VLDL concentration was observed only in the IO-YF-Phy group. In the liver, there was a significant increase (p=0,002) in non-heme Fe concentration in the IO (+83%) and IO-Phy (+117%) groups. Also, GPx activity was significantly increased (p=0,000) in all IO groups. CAT activity was lower (p=0,036) only in the IO-YF-Phy group. A significant increase in hemosiderin deposition around Kupffer cells was observed in all IO groups (p=0,000). Apoptosis was increased in all IO groups, whereas the IO-YF and IO-YF-Phy groups showed the largest number of apoptotic bodies/area (+405% and +342%, respectively) (p=0,000). There was no alteration in the parameters related to bone metabolism. In the IO-YF group, there was a significant increase in Ca apparent absorption (p<0,05).Conclusions: The moderate Fe overload did not alter the serum iron status índices, but led to alterations in the hepatic tissue and in the profile of serum lipids. Except for the profile of serum lipids where only phytate seemed to have a protective effect, in the other evaluated parameters the interaction with yacon flour rich in fructans and/or phytate partially or totally reversed the alterations induced by the moderate Fe overload.
135

English/Language Arts Instruction for Middle/High School Learners with Moderate-to-Severe Disabilities

Mims, Pamela J. 07 October 2015 (has links)
This course is part of the Nancy McKinley Lecture Series, Aligning Literacy Instruction to Standards for Students with Moderate-to-Severe Disabilities (Including Autism), and is presented in partnership with University of Wisconsin-Eau Claire. This course will provide attendees with best practices to teach grade aligned middle and high school English/Language Arts (ELA) content. The best practices highlighted have been derived from rigorous studies conducted with a wide range of students with moderate to severe intellectual disabilities and autism.
136

Etude des effets de programmes d'endurance de haute intensité et de haut volume sur les performances physiques, cognitives ainsi que sur la plasticité musculaire et cérébrale chez le rat sain et ayant subi une ischémie cérébrale / Comparison of high intensity and high volume aerobic training on physical performance, cognition and cerebral and muscular plasticity in healthy rats and after cerebral ischemia

Constans, Annabelle 27 March 2019 (has links)
L’exercice fractionné de haute intensité (HIIT) et continu d’intensité modéré (MOD) représentent les 2 grandes modalités d'endurance. Cependant, leur impact spécifique sur la performance physique et la plasticité cérébrale et musculaire reste controversé du fait de la diversité des protocoles d’exercice proposés chez les sédentaires. Notre 1er axe dégage chez des rats sains l’effet de ces 2 modalités sur la performance physique, la plasticité musculaire et cérébrale sur 8 semaines d’entrainement standardisée dont l'intensité est basées sur le seuil lactique. Nos résultats montrent des gains de performance d’endurance plus rapides et importants suite aux HIIT. La neuroplasticité serait stimulée par les HIIT uniquement et la plasticité musculaire semble spécifique à chacune. L’engouement pour les HIIT se répercute chez les patients subissant un accident vasculaire cérébral où l’efficacité des méthodes d’endurance n’est pas clairement justifiées. Une étude antérieure a montré l’intérêt majeur des HIIT dans la phase aiguë de la pathologie malgré une récupération sensorimotrice incomplète. D’où l’intérêt d’approfondir dans notre second axe l’effet des différentes formes de HIIT (longs et courts) dans la récupération. Nos résultats montrent principalement que ces deux formes de HIIT améliorent la capacité d’endurance et la force de la patte antérieure lésée avec une précocité pour les HIIT longs. Les deux formes de HIIT semblent induire une angiogenèse cérébrale. Néanmoins, ils n’améliorent pas les fonctions sensorimotrices et cognitives. Ainsi, il est nécessaire d’approfondir les répercussions de ces deux entrainements HIIT dans la plasticité musculaire et cérébrale. / Endurance exercise is essential for different reasons in athlete and also in aging and pathological people. Two training modalities were found: high intensity interval training (HIIT) and moderate intensity aerobic training (MOD). However, the specific outcomes of these modalities on physical performance and cerebral and muscular plasticity are controversial because many exercise protocols exist. The 1st study explore the impact of these 2 training on endurance and functional capacity and also on muscular and cerebral molecular modifications throughout 8 weeks in healthy rats. HIIT and MOD programs are work-matched and training intensity are determined thanks to the lactate threshold. Our results show a superior and fast effect on endurance capacity after HIIT compared to MOD. Hippocampal plasticity is stimulated only after HIIT and muscular modifications appear to be specific to each modality. A great interest of HIIT is found in stroke patients for whom evidence of endurance modalities efficiency is still missing. A previous study has shown a beneficial effect of HIIT in the acute phase of stroke despite incomplete sensorimotor recuperation. Hence, the interest to deepen in second part of this manuscript the impact of two HIIT modalities (short and long) in recovery optimisation. Our results show that 2 HIIT strongly improve endurance performance and strength of injured paw with a fast effect for long HIIT. The 2 modalities seem to induce cerebral angiogenesis. However, these 2 training do not increase sensorimotor and cognitive functions. In perspective, it appears necessary to develop muscular and cerebral outcomes induced by these 2 HIIT modalities.
137

Relationships Among Middle School Teachers' Perceptions Regarding Inclusion of Students with Disabilities in General Education Classrooms

Forrester, Stacey O. 01 January 2016 (has links)
Accommodating students with disabilities in a general education class often requires instructional modification and extra student support. Research has shown that making required changes can evoke different responses from teachers and can influence their willingness to accommodate the needs of students with disabilities. However, research has not examined the relationships between middle school teachers' preparation for and experiences with inclusion instruction and their attitudes toward inclusion. The purpose of this correlational study was to explore possible relationships between middle school teachers' attitudes about including students with mild to moderate disabilities in the general education setting and the teachers' education level, length of time teaching, and role as general or special education teachers. Social learning theory informed the study. Teachers from 3 middle schools in a large, primarily suburban school district in the southern United States were identified and sent the link for an online survey that included both demographic questions and the Attitude Toward Teaching All Students validated research instrument (N = 220). Despite several efforts to acquire enough responses to determine statistical significance, the sample obtained (n = 55) was too small for those calculations. However, Spearman correlations calculated with the smaller sample acquired indicated possible relationships between variables and indicated conducting the study in another location with a larger sample would provide valuable insights into teachers' behaviors and beliefs. This study contributes to positive social change by demonstrating a need to examine teachers' background and experiences and their attitudes toward and, as a result, behaviors in inclusion settings.
138

Assessing mathematical creativity : comparing national and teacher-made tests, explaining differences and examining impact

Boesen, Jesper January 2006 (has links)
<p>Students’ use of superficial reasoning seems to be a main reason for learning difficulties in mathematics. It is therefore important to investigate the reasons for this use and the components that may affect students’ mathematical reasoning development. Assessments have been claimed to be a component that significantly may influence students’ learning.</p><p>The purpose of the study in Paper 1 was to investigate the kind of mathematical reasoning that is required to successfully solve tasks in the written tests students encounter in their learning environment. This study showed that a majority of the tasks in teacher-made assessment could be solved successfully by using only imitative reasoning. The national tests however required creative mathematically founded reasoning to a much higher extent.</p><p>The question about what kind of reasoning the students really use, regardless of what theoretically has been claimed to be required on these tests, still remains. This question is investigated in Paper 2.</p><p>Here is also the relation between the theoretically established reasoning requirements, i.e. the kind of reasoning the students have to use in order to successfully solve included tasks, and the reasoning actually used by students studied. The results showed that the students to large extent did apply the same reasoning as were required, which means that the framework and analysis procedure can be valuable tools when developing tests. It also strengthens many of the results throughout this thesis. A consequence of this concordance is that as in the case with national tests with high demands regarding reasoning also resulted in a higher use of such reasoning, i.e. creative mathematically founded reasoning. Paper 2 can thus be seen to have validated the used framework and the analysis procedure for establishing these requirements.</p><p>Paper 3 investigates the reasons for why the teacher-made tests emphasises low-quality reasoning found in paper I. In short the study showed that the high degree of tasks solvable by imitative reasoning in teacher-made tests seems explainable by amalgamating the following</p><p>factors: (i) Limited awareness of differences in reasoning requirements, (ii) low expectations of students abilities and (iii) the desire to get students passing the tests, which was believed easier when excluding creative reasoning from the tests.</p><p>Information about these reasons is decisive for the possibilities of changing this emphasis. Results from this study can also be used heuristically to explain some of the results found in paper 4, concerning those teachers that did not seem to be influenced by the national tests.</p><p>There are many suggestions in the literature that high-stake tests affect practice in the classroom. Therefore, the national tests may influence teachers in their development of classroom tests. Findings from paper I suggests that this proposed impact seem to have had a limited effect, at least regarding the kind of reasoning required to solve included tasks. What about other competencies described in the policy documents?</p><p>Paper 4 investigates if the Swedish national tests have had such an impact on teacher-made classroom assessment. Results showed that impact in terms of similar distribution of tested competences is very limited. The study however showed the existence of impact from the national tests on teachers test development and how this impact may operate.</p>
139

Assessing mathematical creativity : comparing national and teacher-made tests, explaining differences and examining impact

Boesen, Jesper January 2006 (has links)
Students’ use of superficial reasoning seems to be a main reason for learning difficulties in mathematics. It is therefore important to investigate the reasons for this use and the components that may affect students’ mathematical reasoning development. Assessments have been claimed to be a component that significantly may influence students’ learning. The purpose of the study in Paper 1 was to investigate the kind of mathematical reasoning that is required to successfully solve tasks in the written tests students encounter in their learning environment. This study showed that a majority of the tasks in teacher-made assessment could be solved successfully by using only imitative reasoning. The national tests however required creative mathematically founded reasoning to a much higher extent. The question about what kind of reasoning the students really use, regardless of what theoretically has been claimed to be required on these tests, still remains. This question is investigated in Paper 2. Here is also the relation between the theoretically established reasoning requirements, i.e. the kind of reasoning the students have to use in order to successfully solve included tasks, and the reasoning actually used by students studied. The results showed that the students to large extent did apply the same reasoning as were required, which means that the framework and analysis procedure can be valuable tools when developing tests. It also strengthens many of the results throughout this thesis. A consequence of this concordance is that as in the case with national tests with high demands regarding reasoning also resulted in a higher use of such reasoning, i.e. creative mathematically founded reasoning. Paper 2 can thus be seen to have validated the used framework and the analysis procedure for establishing these requirements. Paper 3 investigates the reasons for why the teacher-made tests emphasises low-quality reasoning found in paper I. In short the study showed that the high degree of tasks solvable by imitative reasoning in teacher-made tests seems explainable by amalgamating the following factors: (i) Limited awareness of differences in reasoning requirements, (ii) low expectations of students abilities and (iii) the desire to get students passing the tests, which was believed easier when excluding creative reasoning from the tests. Information about these reasons is decisive for the possibilities of changing this emphasis. Results from this study can also be used heuristically to explain some of the results found in paper 4, concerning those teachers that did not seem to be influenced by the national tests. There are many suggestions in the literature that high-stake tests affect practice in the classroom. Therefore, the national tests may influence teachers in their development of classroom tests. Findings from paper I suggests that this proposed impact seem to have had a limited effect, at least regarding the kind of reasoning required to solve included tasks. What about other competencies described in the policy documents? Paper 4 investigates if the Swedish national tests have had such an impact on teacher-made classroom assessment. Results showed that impact in terms of similar distribution of tested competences is very limited. The study however showed the existence of impact from the national tests on teachers test development and how this impact may operate.
140

Investigation of techniques for improvement of seasonal streamflow forecasts in the Upper Rio Grande

Lee, Song-Weon 01 November 2005 (has links)
The purpose of this dissertation is to develop and evaluate techniques for improvement of seasonal streamflow forecasts in the Upper Rio Grande (URG) basin in the U.S. Southwest. Three techniques are investigated. The first technique is an investigation of the effects of the El Ni??o/Southern Oscillation (ENSO) on temperature, precipitation, snow water equivalent (SWE), and the resulting streamflow at a monthly time scale, using data from 1952 to 1999 (WY). It was seen that the effects of ENSO on temperature and precipitation were confined to certain months, predominantly at the beginning and end of the winter season, and that the effect of these modulations of temperature and precipitation by ENSO can be seen in the magnitude and time variation of SWE and streamflow. The second part is a comparison of the use for snowmelt-runoff modeling of the newly available snowcover product based on imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) with the long-time standard snowcover product from the National Hydrological Remote Sensing Center (NOHRSC). This comparison is made using the Snowmelt Runoff Model (SRM) in two watersheds located inside the URG basin. This comparison is important because the MODIS snowcover product could greatly improve the availability of snowcover information because of its high spatial (500m) and temporal (daily) resolutions and extensive (global) coverage. Based on the results of this comparison, the MODIS snowcover product gives comparable snowcover information compared to that from NOHRSC. The final part is an investigation of streamflow forecasting using mass-balance models. Two watersheds used in the comparison of MODIS and NOHRSC snowcover products were again used. The parameters of the mass-balance models are obtained in two different ways and streamflow forecasts are made on January 1st, February 1st, March 1st and April 1st. The first means of parameter estimation is to use the parameter values from 1990 to 2001 SRM streamflow simulations and the second means is by optimization. The results of this investigation show that mass-balance models show potential to improve the long-term streamflow forecasts in snowmelt-dominated watersheds if dependable precipitation forecasts can be provided.

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