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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.
141

Conversão do Cerrado em pastagem e sistemas agrícolas: efeitos na dinâmica da matéria orgânica do solo / Brazilian savanna conversion to pastures and agricultural systems: effects in the soil organic matter dynamics

Leidivan Almeida Frazão 31 August 2007 (has links)
A mudança de uso da terra no Cerrado acarreta em alterações na dinâmica da matéria orgânica do solo (MOS). Práticas de manejo com revolvimento das camadas de solo aceleram a decomposição da MOS, favorecendo as emissões de gases do efeito estufa do solo para atmosfera. Dessa forma, o objetivo desse trabalho foi avaliar as mudanças na dinâmica da MOS de um Neossolo Quartzarênico submetido a diferentes usos e sistemas de manejo, utilizando como referência o sistema nativo (Cerrado). O presente estudo foi realizado no município de Comodoro - MT (13º50\'00\" a 13º50\'03\" S e 59º37\'18\" O). Foi empregado o delineamento experimental inteiramente casualizado com sete áreas de estudo. As coletas foram realizadas em julho de 2005 e fevereiro de 2006 e as áreas amostradas foram: Cerrado nativo (CER); pastagem (CAP22); plantio convencional com a cultura da soja (CS1), sucessão de culturas arroz-soja (CAS3) e sucessão arroz-soja-sorgo ou milheto (CAS/Sor3 e CAS/M3); e plantio direto (CAP13S/M5). Foram estudadas as seguintes variáveis: atributos físicos e químicos do solo, estoques de carbono (C) e nitrogênio (N) do solo, teores de C e N nas frações granulométricas da MOS, quantidades de N inorgânico, C e N microbiano do solo, quociente metabólico (qCO2) e fluxos de gases do solo (CO2, N2O e CH4). Os resultados deste estudo indicaram que os sistemas com plantio convencional e plantio direto avaliados apresentaram melhoria nos atributos físicos e químicos do solo em relação a pastagem (CAP22), com menor compactação do solo e aumento na disponibilidade de fósforo, cálcio e magnésio. Foram obtidos maiores estoques de C e N em CAS/Sor3 e CAS/M3, áreas com maiores teores de argila. A área CAP13S/M5 também mostrou maiores teores de argila, porém baixos estoques de C e N, resultado atribuído ao uso da terra por treze anos com pastagem sem reforma e ao pouco tempo de implantação do sistema plantio direto. Analisando as frações granulométricas da MOS verificou-se maiores teores de C e N na fração menor que 50 \'mü\'m. As maiores quantidades de N inorgânico em relação ao CER foram observados na área CAS/M3, e com exceção desta área, a forma predominante de N inorgânico foi o amônio. Foram obtidas maiores quantidades de C e N microbiano na época úmida, quando todas as áreas estavam com cobertura vegetal. Entre as áreas de estudo, as maiores quantidades de C e N microbiano foram obtidos em CAP22. Os fluxos de C-CO2, com exceção da área CAS/Sor3, foram maiores na época úmida, enquanto que os fluxos de N-N2O e C-CH4 foram semelhantes entre as épocas de estudo. Os fluxos de gases em C equivalente não apresentaram diferenças significativas entre as áreas de estudo devido ao alto desvio padrão verificado para cada gás. A mudança de uso da terra promove alterações na dinâmica da MOS, porém neste estudo não foi possível distinguir qual o melhor sistema de uso para o Neossolo Quartzarênico devido ao pouco tempo de implantação dos sistemas plantio convencional e plantio direto, e a degradação da pastagem (apesar do maior tempo de implantação) / Land-use changes of Brazilian savanna (Cerrado) result in alterations of the soil organic matter (SOM). Managements practices with tillage accelerate the SOM decomposition, enhancing greenhouse gases emissions from the soil to the atmosphere. Therefore, the objective of this work was to evaluate the changes in the SOM dynamics of a Typic Quartzipisamment submitted to different uses and managements systems, using as reference the native system (Cerrado). The present study was conducted in areas located at Comodoro (Mato Grosso state, Brazil) (from 13º50\'00\" till 13º50\'03\" S and 59º37\'18\" W). At each site, samples were taken randomly within seven areas. Sampling activities were performed in July 2005 and February 2006 and the sample sites consist of an area of \"Cerrado\" (CER); pasture (CAP22); conventional tillage with soybean (CS1), rice-soybean succession (CAS3) and rice-soybean-sorghum or millet (CAS/Sor3 and CAS/M3) successions; and a field with no-tillage system (CAP13S/M5). Studied variables were: physical and chemical attributes, C and N stocks, isotopic composition of 13C/12C and 15N/14N, C and N content in the SOM fractions, quantity of inorganic N, microbial C and N biomass, metabolic quotient (qCO2), and the soil gases fluxes (CO2, N2O and CH4). The results of this study showed that all evaluated fields under conventional or no-tillage systems result in physical and chemical attribute improvement in relation to the pasture (CAP22), with soil compaction decrease, pH increase and improvement of the availability in phosphorus, calcium and magnesium. The C and N stocks were higher in areas CAS/Sor3 and CAS/M3, corresponding to the highest clay content. The area CAP13S/M5 showed similar clay content, but smaller C and N stocks, this result was attributed to the land-use: thirteen years as pastures without reform and also the short time of no-tillage implantation. Analyzing the SOM fractions, it was verified higher C and N contents in the 50 \'mü\'m fraction. The higher quantities of inorganic N in relation to the CER were found in area CAS/M3, and with exception of this area, ammonium was the predominant form of inorganic N. Higher quantities of the microbial C and N were obtained during the wet season, when all areas presented a cover crop. Among areas, the higher quantities of microbial C and N were obtained in CAP22. The fluxes of C-CO2, excepting area CAS/Sor3, were higher during the wet season, while the fluxes of N-N2O and C-CH4 were similar between seasons studied, because high standard deviations were calculated for each gas. The land use promoted alterations in SOM dynamic, however it was not possible to differentiate the best land use for this Typic Quartzipisamment, mainly due to the short time of no-tillage implantation, and the degradation of the pasture (although of the implantation time was higher)
142

Identification des paramètres de bioprocédés environnementaux à partir des mesures accessibles issues de la respiration / Parameters indentification of environmental bioprocesses unsing accessibles measurements from respiration

Lemaire, Cyril 29 June 2015 (has links)
Les bioprocédés environnementaux prennent une place de plus en plus importante dans le paysage industriel mondial. La complexité et la diversité des processus impliqués dans les réactions biologiques de dégradation des polluants limitent considérablement la compréhension et l’utilisation de ces procédés. De plus, les mesures disponibles pour le suivi de cette activité sont souvent hors-ligne et/ou indirectes. Dans ce cadre, les outils de modélisation phénoménologique permettent, via le choix d’hypothèses judicieuses, de lier les observations du système aux processus biologiques sous-jacents. Ces méthodes nécessitent néanmoins l’application d’une étude rigoureuse d’identifiabilité afin de pouvoir exploiter correctement les résultats obtenus. Les modèles ainsi développés permettent de capitaliser des connaissances sur la description des processus biologiques grâce aux mesures effectuées sur le système. Cette approche a été développé au travers de deux cas d’étude, correspondant à deux domaines d’application industrielle. La bioremédiation des sols contaminés aux hydrocarbures constitue la méthode la plus écologique de traitement des sols. Néanmoins, le processus de biodégradation peut être long, voire inexistant en fonction des conditions environnementales. Afin de mesurer l’efficacité de la dégradation, la mesure de la respiration en phase gaz apparaît comme étant l’observation la plus facile à mettre en œuvre. Le problème est que la simple mesure de la consommation d’oxygène est généralement insuffisante. Pour répondre à cette limite, un modèle capable d’expliquer les évolutions du quotient respiratoire apparent grâce aux différentes étapes de la biodégradation a été développé. Cette mesure pourrait alors donner une indication sur l’efficacité de la biodégradation. La seconde partie de ce travail, plus conséquente, s’intéresse à l’épuration des eaux usées par boues activées, elle reprend et amplifie l’approche méthodologique développée pour la biomédiation des sols. L’efficacité de ce traitement des eaux est grandement liée à la production de boues en excès, exprimée par le rendement hétérotrophe. Ce paramètre difficile à maitriser constitue une information primordiale pour la modélisation et la conduite des stations d’épurations. Il apparaît néanmoins que sa définition usuelle ne suffit pas à expliquer ses variations observées. Dans ce cadre, différents modèles phénoménologiques issus des travaux du groupe de travail ASM (Activated Sludge Modeling) ont été étudiés afin de décrire les variations de ce rendement apparent en introduisant les hypothèses réactionnelles liées au stockage du substrat. Une étude expérimentale en laboratoire a permis de confronter ces hypothèses à des mesures de dégradation de substrats purs par des boues activées en respiromètre. L’équilibre entre le stockage du substrat et la croissance bactérienne a ainsi été proposé comme source d’influence majeure sur la valeur du rendement. Ce travail a abouti à une clarification nécessaire de la définition du rendement hétérotrophe. / Environmental bioprocesses are gaining importance in the industrial landscape. Nevertheless, the complexity of mechanisms involved in biological reactions stays an issue for their implementation. Moreover, available measurements of biological activity are often off-tine and/or indirect. ln this context, phenomenological modeling tools are a solution to link observations of the system to underlying biological reactions, considering the right hypotheses. These methods require a rigorous sensitivity analysis in order to properly process the results. Thus, the models permit to obtain precise knowledge about biological systems thanks to indirect measurement. This approach was developed throughout two cases of study corresponding to two industrial fields of application. Bioremediation is the most ecological method for hydrocarbons contaminated soils remediation. Nevertheless, biodegradation can be long or absent depending on environmental conditions. In order to measure its efficiency, respiration measurement in the gas phase seems to be the easiest observation to implement. Oxygen measurement can be insufficient on its own, that is why a model able to describe the evolution of the apparent respiratory quotient has been developed considering the different steps of biodegradation. This observation alone could give insights on the efficiency of biodegradation. The second part of this work deals with activated sludge wastewater treatment using the theoretical approach developed for soil bioremediation. The eftïciency ofthe process depends on the excess production of sludge, which is linked to the heterotrophic yield of the reaction. This parameter is a key component for modeling and optimization of wastewater treatment plant. Most of the time, its common definition is not sufficient to explain its observed variations. In this context, several phenomenological models derived from the activated sludge models were studied to explain these variations, taking into account the substrate storage process. An experimental study was conducted in order to confront the reactional hypothesis of the models to actual measurements of single substrate degradations in respirometer. The balance between substrate storage and direct growth was proposed as a main component of the yield value. This study resulted in a necessary clarification of the heterotrophic yield definition.
143

To Develop and to Evaluate a Mathematics Curriculum for the Mentally Retarded on the Junior High School Level

Miller, Zola Catheryn 08 1900 (has links)
This thesis presents the results of a study conducted to determine the math capabilities of mentally challenged students attending Reagan Junior High School in Wichita Falls, Texas. Survey results are used to determine needed curriculum changes.
144

Die Wertigkeit des sFlt-1/PlGF-Quotienten als Prädiktionsmarker bei Schwangeren mit erhöhtem Präeklampsierisiko

Husse, Sorina Ines 20 January 2015 (has links)
Einleitung: Die Dysbalance proangiogener (Placental Growth Factor = PlGF) und antiangiogener Faktoren (soluble fms-like tyrosine kinase 1 = sFlt-1) gilt heute als pathophysiologische Grundlage bei der Entstehung einer Präeklampsie (PE), eines HELLP-Syndroms (Haemolysis, Elevated Liver enzymes, Low Platelets) oder einer intrauterinen Wachstumsretardierung (IUGR). Der sFlt1/PlGF-Quotient, ein sensitiver und robuster diagnostischer Marker, ist bereits Wochen vor der Krankheitsmanifestation erhöht. Ziel dieser Studie war es, die Wertigkeit des sFlt1/PlGFQuotienten als prädiktiven Faktor bei Risikopatientinnen zu untersuchen. Patienten und Methode: In diese prospektive Studie wurden 68 Patientinnen mit einer Einlingsschwangerschaft und mindestens einem Risikofaktor für das Auftreten einer PE, eines HELLP-Syndrom oder einer IUGR im Schwangerschaftsverlauf eingeschlossen. Die Patientinnen wurden je nach Verlauf der Schwangerschaft in eine Gruppe mit Symptomen (Fallgruppe) und eine Gruppe ohne Symptome (Kontrollgruppe) für eine der oben genannten Erkrankungen unterteilt. Der sFlt1/PlGF-Quotient wurde bei der Aufnahme in die Studie und im weiteren Schwangerschaftsverlauf bestimmt. Ergebnisse: Eine PE, ein HELLP-Syndrom oder eine IUGR trat bei 41 % der Risikopatientinnen auf… Der absolute Wert des sFlt-1/PlGF-Quotienten war nur bei der Gruppe mit Symptomen auf ≥ 85 erhöht und zeigte sich in der 25 + 0-31 + 0 SSW (p = 0,005) und ab der 35 + 0 SSW (p = 0,044) als prädiktiver Faktor für eine PE, ein HELLP-Syndrom oder eine IUGR. Ab 7–10 Wochen vor der Entbindung war, in der Fallgruppe stärker als in der Kontrollgruppe, ein Anstieg des sFlt1/PlGFQuotienten zu beobachten. Dieser war 0–2 Wochen vor der Entbindung bei beiden Gruppen (Kontrollgruppe (MW ± SA 66,9 ± 134) vs. Fallgruppe (MW ± SA 393,3 ± 147,4, p = 0,021) am ,stärksten und zeigte sich ebenfalls als prädiktiver Faktor für eine der genannten Schwangerschaftserkrankungen (p = 0,025). Schlussfolgerung: Bei Risikoschwangeren kann der sFlt1/ PlGF-Quotient für die Einschätzung des individuellen Risikos für eine PE, ein HELLP-Syndrom oder eine IUGR im Schwangerschaftsverlauf genutzt werden. Wiederholte Messungen des Quotienten versprechen eine risikoangepasste Betreuung dieser Patientinnen.:1. BIBLIOGRAFISCHE BESCHREIBUNG 2 2. EINFÜHRUNG 3 2.1. Allgemeines 3 2.2. Klassifikationen 3 2.3. Risikofaktoren 5 2.4. Neue molekulare Erkenntnisse: angiogene Faktoren 6 2.5. Klinische Studien 7 2.6. Differentialdiagnostik anhand angiogener Faktoren 11 2.7. Die Methode für die automatisierte Messung 12 2.8. Die Bedeutung der Dopplersonografie 12 2.9. Weitere Marker und First-Trimester-Screening 13 2.10. Prävention 14 3. PUBLIKATIONSMANUSKRIPT Die Wertigkeit des sFlt-1/PlGF-Quotienten als Prädiktionsparameter bei Schwangeren mit erhöhtem Präeklamsierisiko......................................................15 4. ZUSAMMENFASSUNG DER ARBEIT 22 5. ANLAGEN 27 5.1. Literaturverzeichnis 27 5.2. Erklärung über die eigenständige Abfassung der Arbeit 332 5.3. Lebenslauf 33 5.4. Danksagung 35 / Background: A dysbalance of proangiogenic [placental growth factor (PlGF)] and antiangiogenic [soluble fms-like tyrosine kinase 1 (sFlt-1)] proteins is known to cause the symptoms of preeclampsia (PE), HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) or intrauterine growth restriction (IUGR). An increased sFlt-1/ PlGF ratio ≥ 85 is considered a reliable diagnostic marker. Altered sFlt1 and PlGF concentrations can be detected several weeks prior to the onset of clinical symptoms. In this study we analysed the role of the sFlt1/PlGF ratio as a predictive marker for preeclampsia in a high-risk patient group. Patients and materials: We prospectively included 68 singleton pregnancies with at least one risk factor for PE, HELLP syndrome or IUGR. During the study the patients were divided into one group with symptoms (patient group) and one group without symptoms (control group) for the above-mentioned diseases. The sFlt1/PlGF ratios were measured on admission and during the course of pregnancy. Results: During pregnancy 41 % of patients developed PE, HELLP syndrome or IUGR. An increase of the absolute value of the sFlt1/PlGF ratio ≥ 85 was only observed in the patient group and was found to be a predictive factor for PE, HELLP syndrome or IUGR at 25 + 0 to 31 + 0 weeks of gestation (p = 0.005) and after 35 + 0 weeks of gestation (p = 0.044). Alterations of the sFlt1/PlGF ratio were observed in all patients but were higher in the patient group from 7–10 weeks prior to delivery and with the highest peak 0–2 weeks prior to delivery. Compared to the control group (mean ± SD 66.9 ± 134) absolute values of sFlt1/PlGF ratio were signifi cantly (p = 0.021) increased 0–2 weeks prior to delivery in the patient group (mean ± SD 393.3 ± 147.4). An increase of the sFlt1/PlGF ratio ≥ 85 0–2 weeks before delivery has shown to be predictive for one of the mentioned diseases (p = 0.025).Conclusions: In high-risk patients the sFlt1/PlGF ratio can be used for an individual risk assessment with regard to PE, HELLP syndrome or IUGR. Serial measurements permit a risk-adapted prenatal care of these patients.:1. BIBLIOGRAFISCHE BESCHREIBUNG 2 2. EINFÜHRUNG 3 2.1. Allgemeines 3 2.2. Klassifikationen 3 2.3. Risikofaktoren 5 2.4. Neue molekulare Erkenntnisse: angiogene Faktoren 6 2.5. Klinische Studien 7 2.6. Differentialdiagnostik anhand angiogener Faktoren 11 2.7. Die Methode für die automatisierte Messung 12 2.8. Die Bedeutung der Dopplersonografie 12 2.9. Weitere Marker und First-Trimester-Screening 13 2.10. Prävention 14 3. PUBLIKATIONSMANUSKRIPT Die Wertigkeit des sFlt-1/PlGF-Quotienten als Prädiktionsparameter bei Schwangeren mit erhöhtem Präeklamsierisiko......................................................15 4. ZUSAMMENFASSUNG DER ARBEIT 22 5. ANLAGEN 27 5.1. Literaturverzeichnis 27 5.2. Erklärung über die eigenständige Abfassung der Arbeit 332 5.3. Lebenslauf 33 5.4. Danksagung 35
145

Two Problems in Applied Topology

Nathanael D Cox (11008509) 23 July 2021 (has links)
<div>In this thesis, we present two main results in applied topology.</div><div> In our first result, we describe an algorithm for computing a semi-algebraic description of the quotient map of a proper semi-algebraic equivalence relation given as input. The complexity of the algorithm is doubly exponential in terms of the size of the polynomials describing the semi-algebraic set and equivalence relation.</div><div> In our second result, we use the fact that homology groups of a simplicial complex are isomorphic to the space of harmonic chains of that complex to obtain a representative cycle for each homology class. We then establish stability results on the harmonic chain groups.</div>
146

Cultural Competency of Short-Term Education Abroad Student Participants

Newlon, Kelly Ann 24 June 2019 (has links)
No description available.
147

Interactive Depth-Aware Effects for Stereo Image Editing

Abbott, Joshua E. 24 June 2013 (has links) (PDF)
This thesis introduces methods for adding user-guided depth-aware effects to images captured with a consumer-grade stereo camera with minimal user interaction. In particular, we present methods for highlighted depth-of-field, haze, depth-of-field, and image relighting. Unlike many prior methods for adding such effects, we do not assume prior scene models or require extensive user guidance to create such models, nor do we assume multiple input images. We also do not require specialized camera rigs or other equipment such as light-field camera arrays, active lighting, etc. Instead, we use only an easily portable and affordable consumer-grade stereo camera. The depth is calculated from a stereo image pair using an extended version of PatchMatch Stereo designed to compute not only image disparities but also normals for visible surfaces. We also introduce a pipeline for rendering multiple effects in the order they would occur physically. Each can be added, removed, or adjusted in the pipeline without having to reapply subsequent effects. Individually or in combination, these effects can be used to enhance the sense of depth or structure in images and provide increased artistic control. Our interface also allows editing the stereo pair together in a fashion that preserves stereo consistency, or the effects can be applied to a single image only, thus leveraging the advantages of stereo acquisition even to produce a single photograph.
148

The Relationship between Emotional-Social Intelligence and Leadership Practices among College Student Leaders

Cavins, Bryan Jeremy 07 November 2005 (has links)
No description available.
149

On the Diameter of the Brauer Graph of a Rouquier Block of the Symmetric Group

Trinh, Megan 08 June 2018 (has links)
No description available.
150

Biomaterials Modeling Of Localized Hyperthermia And Drug Delivery For Breast Cancer

Mulamba, Peter January 2008 (has links)
No description available.

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