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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.
401

Perfil eletroforético das proteínas do leite e estabilidade no teste do álcool. / Electrophoretic profile of milk proteins and stability in alcohol test

Barbosa, Rosângela Silveira 30 June 2011 (has links)
Made available in DSpace on 2014-08-20T14:38:44Z (GMT). No. of bitstreams: 1 Tese_Rosangela_Barbosa.pdf: 1566771 bytes, checksum: 708102103c93f84a79e40209c65341e8 (MD5) Previous issue date: 2011-06-30 / Unstable non acid milk (LINA) characterizes for lack of stability of caseins, resulting in coagulation in the alcohol test, without high acidity, above 18°D and with changes in the milk s physic and chemical properties. Among chemical attributes, differences of total crude protein and protein fractions percentages are noticeable between stable and unstable milk. This study aimed to evaluate the relation between milk s electrophoretic profile and stability in the alcohol test with cows being fed with different diets. The trials were conducted at the dairy region of Pelotas, at the south of Rio Grande do sul State, Brazil.The first trial was held at the Embrapa Clima Temperado, from April to August, with two diets: control and feeding restriction, 100 and 60% of previous feeding amounts, with six Jersey cows, at the beginning of their lactation. The second trial was held at the Embrapa Clima Temperado, from May to June, with three diets: control (no additive inclusion), addition of sodium bicarbonate and addition of sodium citrate, with 17 Jersey cows at all lactation stages (76 to 293 days in milking). The third trial was held at the Colégio Agrícola Visconde da Graça UFPEL, from march to April, with three diets: control (deficient), 100% of energy nutritional requirements and 100% of protein-energy nutritional requirements, using 12 Holstein and Jersey cows, at the beginning and mid lactation. In all evaluations the following analyses were performed: alcohol test (with ethanol concentration from 68 to 80°GL v/v), titrable acidity, pH, boiling test, chemical composition, Somatic Cells Count (SCC). Besides, milk production, body weight, body condition score were 12 also evaluated. Milk s protein fractions were evaluate with electrophoreses in 12% poliacrilamide gel. In the first trial, diets did not change protein fraction of the milk not its composition and stability, just milk production. However, stable milk and unstable milk presented differences for κ-CN percentages. In the second, the addition of sodium bicarbonate and addition of sodium citrate, influenced protein fraction β e κ-CN. The unstable milk presented higher amounts of αs-CN. In the third, the adjusted diets could alter milk production, protein, total solids and levels of calcium in milk and blood. / O Leite Instável Não Ácido (LINA) caracteriza-se pela perda da estabilidade das caseínas, resultando em precipitação positiva ao teste do álcool, sem apresentar acidez elevada acima de 18ºD e com alterações nas suas propriedades físico-químicas. Dentre as propriedades químicas destaca-se a diferença na porcentagem de proteína total e das frações protéicas entre leite estável e aquele instável no teste do álcool. O objetivo foi avaliar a relação entre o perfil eletroforético das frações protéicas do leite e sua estabilidade no teste do álcool com vacas recebendo diferentes dietas. Os experimentos foram conduzidos na bacia leiteira de Pelotas, zona sul do Rio Grande do Sul Brasil. O primeiro foi realizado na Embrapa Clima Temperado, nas estações de outono e inverno (de abril a agosto), com dois tratamentos: controle (dieta equilibrada) e restrição alimentar (60% de fornecimento de alimento), em seis vacas em lactação da raça Jersey, no estágio inicial de lactação. O segundo experimento foi realizado na Embrapa Clima Temperado, na estação do outono (maio a junho), com três tratamentos: controle (atendendo 100% das exigências nutricionais), adição de bicarbonato de sódio e adição de citrato de sódio, usando 17 vacas da raça Jersey, com média de 30 semanas de lactação). O terceiro experimento foi realizado no Colégio Agrícola Visconde da Graça UFPel, 10 nas estações: final de verão e início do outono (março a abril), com 3 tratamentos: controle (sem atender as necessidades nutricionais dos animais), 100% de atendimento das exigências energéticas e 100% de atendimento das exigências energético-protéicas, usando 12 vacas da raças Jersey e Holandês, no primeiro e segundo estádio de lactação. Em todas as etapas foram realizadas as análises: teste do álcool (68 a 80ºGL v/v, acidez titulável, pH, fervura, composição química (gordura, proteína, lactose, sólidos totais), contagem de células somáticas. Foram avaliados os parâmetros de produção de leite, peso corporal, escore da condição corporal. Além dessas, foi realizado eletroforese em gel de poliacrilamida 15% para determinação das frações protéicas do leite. No primeiro experimento, conclui-se que as dietas não alteraram as frações protéicas, composição e estabilidade do leite e parâmetros produtivos das vacas em estudo, com exceção da produção de leite. Já com relação a comparação de leite estável e leite instável no teste do álcool houve diferenças na fração protéica β-caseína. O grupo de vacas com menor estabilidade do leite apresentou menor proporção de β, mas maior de k-CN, caseína total e proporção de caseína. No segundo experimento, os aditivos bicarbonato de sódio e citrato de sódio influenciaram apenas as frações protéicas β e κ-caseína. O leite instável apresentou maiores quantidades de αs-caseína. No terceiro experimento, as dietas ajustadas foram suficientes para reverter o quadro de LINA, causar influência na produção do leite, proteína, sólidos totais e teor de cálcio no leite e sangue.
402

Číselná osa a její chápání u žáků základní školy / Number Line and its Understanding by Primary School Pupils

Špačková, Klára January 2017 (has links)
This diploma thesis deals with the number line as a tool to improve pupil's understanding of various mathematical concepts, structures, properties and algorithms. The aim of the thesis is to determine how are lower secondary pupils able to use the number line and to connect findings with the content of their textbooks. The thesis consists of a theoretical and a practical part. The theoretical part introduces the topic of number line, deals with the problems used for testing in the Czech Republic and presents several researches on this topic. The theoretical part, together with the analysis of current state of the number line usage in teaching, serves as a basis for an experimental investigation that is covered in the practical part. After a pilot testing with 19 pupils, the main testing was conducted in 7 classes of two Prague primary schools. The total of 156 pupils participated in the main testing and 8 of the pupils were later interviewed about their tests. The results are presented in the practical part. It turned out that there is a correspondence between textbook content and pupils' errors while working with number line and that pupils struggle with representing of fractions on the number line. In the conclusion some recommendation for teachers were put forward concerning the usage of the...
403

Etude phytochimique et activités biologiques de Diplotaxis sp. : application à l'étude des cellules souches coliques pathologiques / Phytochemical studies and biological activities of diplotxis species : application to the study of pathological colonic stem cells

Nasri, Imen 29 September 2016 (has links)
Les plantes médicinales Diplotaxis harra et Diplotaxis simplex occupent une place importante dans la pharmacopée traditionnelle grâce à leurs compositions variées en métabolites secondaires tels que les flavonoïdes. Ces derniers jouent un rôle important dans plusieurs activités biologiques, notamment anti-inflammatoires et anti-cancéreuses. Dans ce contexte, et à la recherche de molécules bioactives dans D. harra et D. simplex, nous avons mis au point un nouveau modèle d'étude in vitro des cellules souches à l'origine des pathologies inflammatoires et cancéreuses coliques où leur survie dépend de l'activation de la Glycogène Synthase Kinase 3beta (GSK3beta) en aval du récepteur de protéases inflammatoires PAR2. Ce modèle a permis la purification bioguidée de glucoflavonoïdes à partir d'un extrait méthanolique des fleurs de D. harra capables d'inhiber GSK3beta via la voie PKC. Ainsi, l'Isorhamnétine-3,7-di-O-glucoside s'est révélé cytotoxique vis à vis des cellules inflammatoires ou cancéreuses coliques tout en épargnant les cellules normales. D'autre part, en raison de l'intérêt grandissant porté aux fractions volatiles en thérapeutique, nous avons étudié les compositions chimiques et les activités antioxydantes des fractions volatiles des feuilles et des fleurs de D. simplex. En se basant sur la technique chromatographique en phase gazeuse couplée à la spectrométrie de masse (GC-MS), nous avons montré que les deux fractions volatiles contiennent des quantités importantes de composés soufrés/azotés, parmi lesquels le 5-methylthiopentanenitrile et le 1-isothiocyanatobutane pourraient être impliqués dans l'effet antioxydant des fleurs de D. simplex. En conclusion, nos travaux ont permis de révéler l'axe PAR2/GSK3beta comme une nouvelle voie de survie des cellules souches coliques et l'intérêt thérapeutique des glucoflavonoïdes et des fractions volatiles de l'espèce Diplotaxis. / The medicinal plants Diplotaxis harra and Diplotaxis simplex occupy an important place in traditional medicine due to their varied compositions in secondary metabolites such as flavonoids. Flavonoids play an important role in many biological activities, including inflammation and cancer. In this context and in search of bioactive molecules in D. harra and D. simplex, we have developed a new study model, in vitro, where colonic stem cells causing inflammatory diseases and colorectal cancer survive through the activation of Glycogen Synthase Kinase 3beta (GSK3beta) downstream of inflammatory proteases PAR2 receptor. This model allowed the bio-guided purification of glucoflavonoids from a methanol extract of D. harra flowers able to inhibit GSK3beta via a PKC-dependent pathway. Thus, isorhamnetin-3,7-di-O-glucoside was found to be cytotoxic against inflammatory or colon cancer cells while sparing normal cells. On the other hand, due to the growing interest in therapeutic volatile fractions, we studied the chemical composition and antioxidant activity of volatile fractions of leaves and flowers of D. simplex. Based on the gas chromatography mass spectrometry technique (GC-MS), we have shown that both volatile fractions contain significant amounts of sulfur/nitrogen compounds, including 5-methylthiopentanenitrile and 1-isothiocyanatobutane, which might be involved in the antioxidant effect of flowers from D. simplex. In conclusion, our work revealed the axis PAR2/GSK3beta as a new survival pathway for colon stem cells and the therapeutic value of glucoflavonoids and volatile fractions of Diplotaxis species.
404

Uso de elementos da cultura infanto-juvenil na introdução do conceito de fração

Assumpcao, Sergio Dias January 2013 (has links)
As dificuldades apresentadas pelos alunos, ao chegarem ao 6º ano do ensino fundamental, sempre me intrigaram. A busca de maneiras para minimizá-las foi o ponto de partida desta proposta de dissertação. Ao longo de minha experiência profissional identifiquei que muitas colegas dos anos iniciais não se sentiam confortáveis ao trabalharem com a matemática, muitas pediam auxilio, enquanto outras apenas reproduziam, mecanicamente, o que lhes fora ensinado. Trabalhar com estas colegas pareceu-me a solução natural para meus anseios. Desenvolver um material que pudesse auxiliá-las em sala de aula e, ao mesmo tempo, que fosse familiar ao aluno, levou-me à opção do uso da linguagem das histórias em quadrinhos e dos desenhos animados. Conversas e questionários com as professoras de anos iniciais indicaram o ensino de frações como o conteúdo em que os alunos apresentavam maiores dificuldades. Isto levou-me a optar por desenvolver o projeto para este conteúdo especifico. A análise de dissertações, livros e artigos relativos ao tema trouxeram os diferentes conceitos envolvidos: operador multiplicativo, razão, quociente, medida e, o escolhido para ser o foco do trabalho, parte-todo. A elaboração de roteiros, desenhar, digitalizar e por último animar o material através de softwares específicos geraram as histórias em quadrinhos e os desenhos animados que são o produto final desta dissertação. Com o material pronto, foram ofertadas oficinas de preparação aos professores. Nestas oficinas surgiram dificuldades maiores do que as previstas, conduzindo a uma reconstrução do material para adequá-lo à realidade apresentada. Esta caminhada está registrada neste trabalho. / The difficulties presented by the students upon arrival at the 6th grade level, have always intrigued me. The search for ways to overcome them was the starting point for this dissertation proposal. Throughout my professional experience, I identified that many of my colleagues of the early years were not comfortable when working with mathematics, so many of them asked for assistance, while others merely reproduced mechanically what they had been taught. Working with these colleagues seemed to me the natural solution to my desires. Develop a material that could help them in the classroom and, at the same time this was familiar to the student, took me the option of using the language of comics and cartoons . Questionaires and conversations with teachers of the early years have indicated the teaching of fractions as the topic that the students had more difficulties. This led me to choose to develop the design for this specific content. A review of dissertations, books and articles on the subject brought the different concepts involved: multiplicative operator, reason, ratio, measure, and chosen to be the focus of the work, part-whole. The roadmapping, draw, scan and finally animate the material through specific software generated the comics and animes final product of this work and, with the material ready, worshop of preparation were offered to teachers. In these workshops have appeared more difficulties than we have previewd, it lead this to a reconstrution of the material to fit the reality presented. This hike is recorded in this work.
405

Optimisation of the ILC vertex detector and study of the Higgs couplings / Développement d'un détecteur de vertex de nouvelle génération pour le collisionneur ILC : impact sur la détermination des rapports d'embranchement du boson de Higgs standard

Voutsinas, Georgios 28 June 2012 (has links)
Cette thèse est une contribution au document intitulé "Detector Baseline Document (DBD)" décrivant le conceptde détecteur ILD envisagé auprès du collisionneur linéaire international électron-positon ILC (acronyme del'anglais International Linear Collider).Les objectifs de physique de l'ILD nécessitent un détecteur de vertex (VXD) particulièrement léger, rapide et trèsgranulaire permettant d'atteindre une résolution sans précédent sur le paramètre d'impact des trajectoiresreconstruites des particules produites dans les interactions étudiées. Le principal objectif de cette thèse est demontrer comment optimiser les paramètres du VXD dans le cas ou il est composé de Capteurs à Pixels Actifsfabriqués en technologie industrielle CMOS (CAPS). Ce travail a été réalisé en étudiant la sensibilité desperformances d'étiquetage des saveurs lourdes et de la précision sur les rapports d'embranchement hadroniquedu boson de Higgs aux différents paramètres du VXD.Le cahier des charges du VXD, particulièrement ambitieux, a nécessité le développement d'une nouvelletechnologie de capteurs de pixels de silicium, les CAPS, dont le groupe PICSEL de l'IPHC est à l'origine. Lavitesse de lecture et l'influence des paramètres qui régissent la fabrication des capteurs en fonderie ont étéétudiées dans cette thèse, et des prototypesde CAPS ont été caractérisés sur faisceau de particules. Enfin, les performances de trajectométrie d'un VXDcomposé de CAPS a été évalué avec des études de simulation. / This thesis is a contribution to the " Detector Baseline Document ", describing the ILD detector which is intendedfor the International Linear Collider (ILC).The physics goals of the ILD call for a vertex detector (VXD) particularly light, rapid and very granular allowing toreach an unprecedented resolution on the impact parameter of the tracks that reconstruct the particles producedin the studied interactions. The principle goal of this thesis is to show how to optimise the parameters of the VXDin the case that is composed of Active Pixel Sensors manufactured in industrial CMOS technology (CAPS). Thiswork has been realised by studying the sensitivity of the performance of the heavy flavour tagging and theprecision on the hadronic branching fractions of the Higgs boson as a function of different sets of VXDparameters.The specifications of the VXD, particularly ambitious, call for the development of a novel silicon pixel sensorstechnology, the CAPS, which was pioneered by the PICSEL group of IPHC. The readout speed and the influenceof the fabrication parameters have been studied in this thesis, and CAPS prototypes have been characterised intest beams. Finally, the tracking performance of a CAPS based VXD has been evaluated with simulation studies.
406

Integrating internet technology to support fraction instruction in the elementary classroon

Jacksin, Melonie Ann 01 January 2000 (has links)
No description available.
407

Phosphorus in Preferential Flow Pathways of Forest Soils in Germany.

Julich, Dorit, Feger, Karl-Heinz 27 March 2017 (has links)
The transport of nutrients in forest soils predominantly occurs along preferential flow pathways (PFP). This study investigated the composition of phosphorus (P) forms in PFPs and soil matrix in several temperate beech forests with contrasting soil P contents in Germany. The PFPs were visualized using dye tracer experiments. Stained and unstained soil was sampled from three profile cuts per plot and analyzed for P fractions. The results show that labile P concentrations were highest in the O-layer and had the same range of values at all sites (240–320 mg·kg−1), although total P (TP) differed considerably (530–2330 mg·kg−1). The ratio of labile P to TP was significantly lower in the P-rich soil compared to the medium and P-poor soils. By contrast, the ratio of moderately labile P to TP was highest at the P-rich site. The shifts in P fractions with soil depth were generally gradual in the P-rich soil, but more abrupt at the others. The contents of labile and moderately labile P clearly differed in PFPs compared to soil matrix, but not statistically significant. The studied soils are characterized by high stone contents with low potential for P sorption. However, indications were found that labile organically bound P accumulates in PFPs such as biopores.
408

In-vitro bioactivity of fractions from a local medicinal plant on HIV-1 replication, and selected fungal and bacterial pathogens

Mutshembele, Awelani Mirinda 03 1900 (has links)
MSc (Microbiology) / Department of Microbiology / See the attached abstract below.
409

Frequency of occurrence of rain from liquid-, mixed-, and ice-phase clouds derived from A-Train satellite retrievals

Mülmenstädt, Johannes, Sourdeval, Odran, Delanoë, Julien, Quaas, Johannes January 2015 (has links)
A climatology of thermodynamic phase of precipitating cloud is presented derived from global—land and ocean—, retrievals from Cloudsat, CALIPSO, and Moderate Resolution Imaging Spectroradiometer. Like precipitation rate, precipitation frequency is dominated by warm rain, defined as rain produced via the liquid phase only, over the tropical oceans outside the Intertropical Convergence Zone and by cold rain, produced via the ice phase, over the midlatitude oceans and continents. Warm rain is very infrequent over the continents, with significant warm rain found only in onshore flow in the tropics, and over India, China, and Indochina. Comparison of the properties of precipitating and nonprecipitating warm clouds shows that the scarcity of warm rain over land can be explained by smaller effective radii in continental clouds that delay the onset of precipitation. The results highlight the importance of ice-phase processes for the global hydrological cycle and may lead to an improved parameterization of precipitation in general circulation models.
410

Det laborativa materialets och arbetssättens plats i läromedel och undervisning : En kvalitativ studie som undersöker hur laborativt material och arbetssätt framhålls och behandlas inom området bråk i olika läromedel, samt hur lärare beskriver att de undervisar utifrån detta / The place of the laboratory material and working methods in teaching materials and teaching : A qualitative study that examines how laboratory material and working methods are highlighted and treated in the field of fraction in different teaching materials, and how teachers describe that they teach based on this

Elin, Tarakkamäki, Sanna, Jaska January 2020 (has links)
Studien syftar till att få kunskap om hur laborativt material och arbetssätt framhålls och behandlas inom området bråk i olika läromedel. Vidare undersöker vi även hur lärare undervisar laborativt utifrån dessa läromedel. För att samla in data har vi använt oss av metodtriangulering i form av granskning av läromedel och intervjuer. De läromedel som har granskats är Favorit matematik, Eldorado och Prima matematik. För att bredda kunskapen inom området intervjuades lärare som var aktiva användare av dessa läromedlen i sin undervisning. Med hjälp av variationsteorin har vi även analyserat de laborativa inslagen i läromedlen för att se på dess relevans i relation till variationsmönstrena kontrastering och generalisering och därmed hur elevers lärande främjas genom läromedlens föreslagna arbetssätt. Resultatet visar att de tre granskade läromedlen skiljer sig åt samtidigt som de har många likheter. Samtliga läromedel har tagit i beaktning att det laborativa materialet behöver ta plats i undervisningen på ett eller annat sätt. Dessa läromedel ger eleverna möjlighet att utforska med något slags laborativt material. Studiens slutsats blir således att vi kan se att läromedlen, på ett eller annat sätt, bidrar med laborativt material och arbetssätt. Utifrån variationsteorins sätt att se på lärande passar Eldorados laborativa arbetssätt bäst in på de variationsmönster vi granskat. / The study aims to gain knowledge about how laboratory material and working methods are highlighted and treated in the field of fraction in different teaching materials, and how teachers describe that they teach based on this. In order to collect data, we have used method triangulation in the form of examination of teaching material and interviews. The teaching materials that have been examined are Favorite Mathematics, Eldorado and Prima Mathematics. To broaden the knowledge in the field, teacher 's who were active users of these teaching materials were interviewed in their teaching. Using the theory of variation, we have also analyzed the laboratory elements in the teaching materials to look at its relevance in relation to the variation patterns of contrast and generalization and thus how pupils' learning is promoted through the proposed teaching methods. The result shows that the three study materials examined differ at the same time as they have many similarities. All teaching materials have taken into account that the laboratory material needs to take place in the teaching in one way or another. These teaching materials allow students to explore with some kind of laboratory material. The study's conclusion thus becomes that we can see that the teaching aids, in one way or another, contribute with laboratory material and working methods. Based on variation theory's approach to learning, Eldorado's laboratory approach fits best with the variation patterns we examined.

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