O número de ações de restauração ecológica no bioma Mata Atlântica tem crescido, e a semeadura direta tem sido apontada como uma técnica complementar ao plantio de mudas de árvores, especialmente devido à possibilidade de diminuição dos custos. O presente experimento buscou testar o uso dessa técnica em larga escala, ao propor a rápida ocupação e cobertura (preenchimento) de duas áreas agrícolas degradadas com baixa resiliência através da semeadura direta de espécies de rápido crescimento e boa cobertura de copa. Em um segundo momento buscou-se utilizar a semeadura direta para enriquecimento dessas áreas. A implantação ocorreu na Usina São João, Araras, estado de São Paulo, em duas Áreas de Preservação Permanente abandonadas após uso agrícola (Área 1 e Área 2). Para a semeadura direta de preenchimento foram utilizadas 16 espécies arbóreas nativas, em cujos lotes de sementes foram realizados testes de germinação em laboratório. O delineamento experimental foi o inteiramente aleatorizado na Área 1 (48 parcelas de 200m2 0,96ha) e o de blocos casualizados na Área 2 (30 parcelas de 300m² 0,90ha). Foram aplicados três tratamentos em campo, baseados em três diferentes densidades de sementes, calculadas com base em uma projeção de indivíduos esperada no campo (Área 1 16 repetições / Área 2 10 repetições). Ao longo de 15 meses após a semeadura (A.S.) na Área 1 e 6 meses A.S. na Área 2 foi monitorado o número de indivíduos sobreviventes. Na Área 1 também ocorreu o monitoramento de altura e cobertura de copa nas linhas de semeadura (CL) por 34 meses A.S. As taxas de emergência foram cerca de 70-90% menores que as obtidas em laboratório. Mesmo assim, as densidades de indivíduos foram elevadas e diretamente relacionadas às diferentes densidades de sementes utilizadas, alcançando-se projeções de 1.215 ind.ha-1 a 13.002 ind.ha-1. Em um a três meses A.S. a densidade de indivíduos já tinha alcançado valores próximos aos obtidos no final dos monitoramentos. Aos 34 meses A.S. houve registro de indivíduos com <0,50m a 7,01-8,0m de altura, com o maior percentual (29,05%) na faixa dos 3,01m 4,0m de altura. Também aos 34 meses A.S., mais de 70% das linhas de semeadura apresentaram valores de CL acima de 101%. O custo para aquisição de sementes para obter uma muda no campo a partir de semeadura direta da maioria das espécies utilizadas pode ser duas a três vezes menor que o preço de uma muda em viveiro. Após o preenchimento das duas áreas experimentais, foram implantadas as semeaduras diretas de enriquecimento, com 30 espécies na Área 1 e 35 espécies na Área 2. Problemas relacionados à infestação por plantas daninhas, revolvimento do solo por animais e predação por formigas dificultaram a emergência das plântulas. A semeadura direta de espécies arbóreas nativas de preenchimento mostrou-se efetiva tanto técnica como economicamente para a ocupação inicial de áreas agrícolas em restauração. Porém, a efetividade é dependente das espécies utilizadas e das condições específicas do local, como o solo, sendo necessário realizar diagnósticos prévios à implantação e mesmo considerar o plantio de mudas como técnica complementar. / The number of restoration projects in the Atlantic Forest biome is increasing, and direct seeding has been identified as a complement technique to the planting of tree seedlings, especially considering the possibility of reducing the costs of the activity. This experiment sought to test the large scale use of this technique, by proposing the fast occupation and coverage (filling) of two degraded agricultural lands with low resilience through direct seeding of fast growing and wide canopy tree species. In a second moment, it was tested the use of direct seeding to increase plant richness of these areas. The experiment was set at the Usina São João, Araras, São Paulo state, in two Permanent Preservation Areas (riparian areas) abandoned after agricultural use (Area 1 and Area 2). For the filling direct seeding, 16 native tree species were used, in which seed germination tests were carried out in laboratory. The experimental design was the completely randomized in Area 1 (48 plots of 200m² 0,96ha) and the randomized blocks in Area 2 (30 plots of 300m² 0,90ha). Three treatments were tested in the field, based on three different densities of seed sowing, calculated according to an expected projection of individuals number (Area 1 16 repetitions / Area 2 10 repetitions). The number of surviving individuals was monitored over 15 months after seeding (A.S.) in Area 1 and 6 months A.S. in Area 2. Tree height and canopy cover were also monitored in Area 1 in the seeded lines (CL) during 34 months A.S. Emergence rates were about 70-90% lower than those obtained in laboratory. Even so, the densities of individuals were elevated and directly related to the different densities of seeds used, reaching a projected density on the experimental plots of 1,215 ind.ha-1 to 13,002 ind.ha-1. In one to three months A.S., the density of individuals had already reached levels close to those obtained at the end of monitoring. Thirty four months A.S., individuals of <0.50m to 7.0m-8.0m high were recorded, with the largest percentage (29.05%) in the range of 3.01m-4.0m. In this evaluation, over 70% of seeded lines showed CL above 101%. The expenses with seed acquisition to obtain a single seedling in the field from direct seeding of most species used was two to three times lower than the price of an individual seedling in nurseries. After covering the two experimental areas, direct seeding was implanted to increase plant richness, with 30 species in Area 1 and 35 species in Area 2. Problems related to weed infestation, soil disturbance by animals and predation by ants hindered seedling emergence. Direct seeding of native tree species was both technically and economically effective to the initial occupation of agricultural lands through restoration. However, effectiveness is dependent on the species used and the local site conditions, such as soils, being necessary a pre-implantation diagnosis and even the need of seedling plantation as a complementary technique.

A população de plantas é um dos fatores que impacta fortemente na produtividade da cultura do milho (Zea mays); justá-la localmente é uma das estratégias para gerenciar a variabilidade das lavouras e otimizar o uso de recursos do ambiente que não estão sob o controle do produtor rural, como o tipo de solo e a capacidade de retenção de água. O objetivo desse estudo foi investigar a produtividade de híbridos de milho submetidos à semeadura em taxas variáveis (STV) em unidades de gestão diferenciada (UGD). Foi utilizado o total de dez híbridos de milho testados em cinco níveis de populações de plantas a partir da população regularmente recomendada (60%, 80%, 100%, 120% e 140%). Foram conduzidos cinco experimentos em talhões comerciais entre os anos de 2012 e 2015, no Brasil, na região Centro-Oeste (Maracajú -MS), durante a segunda safra de verão (safrinha) e na região Sul (Piraí do Sul - PR), durante a safra de verão. A pesquisa foi dividida em duas etapas principais: (1) delimitação das UGD e (2) implantação dos experimentos em faixas variando híbridos e população de plantas ao longo das UGD. Foram utilizados mapas históricos de produtividade (MP), mapa de condutividade elétrica do solo (CE) e mapa de altitude como atributos que deram origem às UGD. Dois métodos distintos de agrupamentos foram analisados: o método de \"cluster\" por \"K-means\" e o método pela média normalizada. As análises das UGD foram realizadas com base na estatística descritiva. Os experimentos em faixas tiveram os dados de produtividade referentes aos híbridos, população e UGD submetidos às análises de variância pelo F-teste e ANOVA e análise de regressão em função dos níveis de população de plantas por área. Foi possível discriminar, através das UGD, diferentes níveis de produtividade, CE do solo e concentração de nutrientes (CE, pH, CTC Efetiva, Argila, Areia, V%, M.O, e K), indicando que os procedimentos utilizados nesse estudo para a definição de UGD foram eficientes. O método de formação de UGD pela média normalizada proporcionou maior homogeneidade interna das UGD comparativamente ao método de \"Cluster K-means\". A qualidade da distribuição longitudinal medida pelo espaçamento entre plantas (indicador da efetividade dos níveis de população) variou de 81% a 90% de espaçamentos aceitáveis entre os locais avaliados. A análise de variância foi significativa (P<0,05) para interação tripla entre híbridos, população de plantas e UGD assim com as regressões foram significativas e os melhores modelos tiveram ajuste quadrático para população e produtividade na área da região Centro-Oeste - MS. Nas áreas da região Sul os experimentos não foram significativos. A população de plantas ótima pode diferir em até 5743 pl ha-1 entre as diferentes UGD dentro de um mesmo talhão. Quanto menor a média de produtividade do talhão, mais restritiva é a faixa de população ótima. No entanto, não há uma recomendação simples a respeito da população de plantas ótima para cada UGD. / Plant population per unit area is one of the most important aspects under the farmer\'s control that can influence maize grain yield. As the availability of resources for the growth of plants (like water availability and soil attributes) are not uniform along the fields, and considering the unfeasibility to change the environment setting, plant population per area is a key aspect under the farmer\'s control to optimize the use of these resources. This study aims to carry a comprehensive study of the strategy of variable rate seeding (VRS) within zones of distinct resource availability (management zones - MZ). A seasonal experimental design was set consisting in selecting ten different hybrids and five ranks of plant populations starting with a local recommended seeding rate and offsetting it in 40% and 20% below and above this reference. Five field experiments were conducted in commercial fields from 2012 to 2015 in two regions with distinct growing seasons in Brazil. In the Midwest region (Maracaju - MS) where corn is grown as a secondary crop following soybean within one season, and in the Southern region (Piraí do Sul - PR) where corn is grown as primary crop during the summer season; both under rain fed and no-tillage system. This research was split into two main stages: (1) definition of management zones (MZ) within agricultural fields and (2) implementation of strip tests varying hybrids and plant populations across MZ. The attributes used to delineate MZ were soil electrical conductivity (EC), yield maps (YM) and elevation. Two methods were analyzed to delineate MZ: cluster K-means and standardized average. MZ were analyzed by descriptive statistics. On the experimental data gathered from each seasonexperiment, yield of the hybrids, plant density and MZ were submitted to analysis of variance by F-test, ANOVA and regression analysis. MZ were able to differentiate levels of yield, and soil properties (EC, pH, Effective CTC, clay, sand, V%, MO, and K), suggesting that the procedures to define MZ used in this study were efficient. The standardized average provides greater internal homogeneity of MZ compared with the Cluster K-means. The quality of regular spacing between plants (indicator of seed rate quality) was 90% to 81% at all locations. The analyses of variance were significant (P < 0.05) for triple interaction between hybrids, plant population, and for the MZ at the Midwest region. For fields studied in the South the tests were not significant. The optimal plant population at the Midwest region can vary by up to 5743 pl ha-1 across MZ within the same field. Lower yield averages have a narrow optimal plant population interval. However, there is no simple recommendation regarding the optimal plant population across MZ.

Master of Science / Department of Agronomy / Scott A. Staggenborg / Spatial variability in plant available water can be caused by uncontrollable factors such as topography and soil texture as well as controllable factors such as residue management. Research located on the High Plains evaluated the impact of wheat (Triticum aestivum L.) stubble height on snow catch, plant available water at seeding, and optimal corn seeding rates. Treatments consisted of stripper harvest height of 71 cm (28 in.), cut heights of 25 cm (10 in.), and 10 cm (4 in.) Measured snow depths were significantly different among treatments (p<0.0001) with equivalent precipitation of 5.77 (2.27), 3.25 (1.28), and 1.73 cm (0.68 in.) for the stripped, 25 cm, and 10 cm heights respectively. Available soil water at planting increased 24% as stubble height increased from 10 to 71 cm (4 to 28 in) in one year of the study. Two corn hybrids of varying maturity (97 and 108 days) were planted into the stubble treatments at seeding rates ranging from 2.47 to 5.43 plants m[superscript]-2 (10 to 22 000 plants ac[superscript]-1). In the dry year, the long season hybrid responded positively to increasing population in tall stubble and negatively in short stubble. Yield of the short season hybrid increased with increasing stubble height and was mostly unresponsive to population. Grain yields of both hybrids responded positively to increasing plant population in a wet year. Treatments also affected the yield components of yield plant[superscript]-1, kernel weight, and kernels plant[superscript]-1. Managing seeding rates for uncontrollable factors was attempted with small-plot and field scale research across 3 fields in northeast Kansas. A relationship between soil electro-conductivity (EC) and measured water holding capacity values was developed for one study field. This quadratic relationship was significant (p<0.0001) and explained variability in water holding capacity with respect to EC quite well (R[superscript]2=0.6239). Responses from small plots showed that sites differing in population response characteristics could be identified. Field scale data was used to derive a function describing optimal seeding rate with respect to soil EC. In the field under study, optimal seeding rates varied from 3.08 to 8.74 plants m[superscript]-2 (12 500 to 35 375 plants ac-1).

The process of environmental degradation that has been occurred in the lower region of Sao Francisco s river is reducing the permanent preservation areas. The artificial regeneration is a method of riparian restoration widely used to reconstitute the native vegetation in degraded areas. For the reasons set was a work of restoration in an area of riparian forest in Santana do São Francisco s county Sergipe, with the objective of proposing models to restore the natural balance of the environment. The studied area after tested was monitored for 60 months, using the experimental design in randomized blocks in three models restoration the riparian forest (seedlings growth of forest species in spacing 3x1,5m and 3x3m and direct seeding in spacing 3x1,5m) and twelve native forest species. There were evaluated seedling emergence, surviving and development of species tested (height, base diameter e the relative growth rate). Was also performed to evaluated phenological aspects of species tested and identified the presence of colonizing species in the studied area. The results after 60 months old of the implanted species indicated a higher percentage of surviving of species in the model with growth in spacing 3x1,5m (62,2%). It was observed that the spacement used not able to influence the development of species. To TCR (relative growth rate) was identified as the pioneer species Schinus terebinthifolius (Raddi.) had the highest rates of growth in height in three models implanted. With respect to the diameter base was observed that the species that showed the highest growth rates were Vitex polygama (Cham.), Schinus terebinthifolius (Raddi.) e Cassia grandis (L.f). Considering the phenological aspects were observed that five species (40%) showed flowering and fruiting during the 60 months of evaluation. The species studied showed up in the potential restoration of riparian forests and may be the recommended direct seeding method to reduce the costs of deployment in the lower region of Sao Francisco s river. / O processo de degradação ambiental que vem ocorrendo na região do Baixo Rio São Francisco vem reduzindo as áreas de preservação permanente. A regeneração artificial é um método de restauração ciliar muito utilizado para recompor a vegetação nativa em áreas degradadas. Pelos motivos apresentados foi realizado um trabalho de restauração em uma área de mata ciliar no município de Santana do São Francisco SE, com o objetivo de propor modelos de restabelecimento do equilíbrio natural do ambiente. A área de estudo, após implantada foi monitorada por 60 meses, sendo utilizado o delineamento experimental em blocos casualizados em três modelos de restauração da mata ciliar (plantio de mudas de espécies florestais em espaçamentos 3x1,5m e 3x3m e semeadura direta em espaçamento 3x1,5m) e doze espécies florestais nativas. Foram feitas avaliações de emergência de plântulas, sobrevivência e desenvolvimento das espécies implantadas (altura, diâmetro do colo e taxa de crescimento relativo). Também foi realizada a avaliação dos aspectos fenológicos das espécies implantadas e identificada a presença de espécies colonizadoras na área de estudo. Os resultados obtidos após 60 meses de idade das espécies implantadas indicaram um maior percentual de sobrevivência no modelo com plantio de mudas no espaçamento 3x1,5m (62,2%). Observou-se que os espaçamentos utilizados não exerceram influência no desenvolvimento das espécies. Para a TCR (taxa de crescimento relativo) foi identificado que a espécie pioneira Schinus terebinthifolius (Raddi.) apresentou as maiores taxas de crescimento em altura nos três modelos implantados. Com relação ao diâmetro do colo observou-se que as espécies que apresentaram as maiores taxas de crescimento foram Vitex polygama (Cham.), Schinus terebinthifolius (Raddi.) e Cassia grandis (L.f). Considerando-se os aspectos fenológicos foram observados que cinco espécies (40%) apresentaram floração e frutificação durante os 60 meses de avaliação. As espécies estudadas apresentaram-se potenciais no processo de restauração de matas ciliares, podendo ser recomendado o método de semeadura direta para reduzir os custos da implantação na Região do Baixo Rio São Francisco.

Parmi les nouveaux matériaux massifs pour le silicium photovoltaïque (PV), le silicium multicristallin haute performance (HPmc-Si) a émergé en raison de son rendement de conversion supérieur à celui du silicium multi-cristallin (mc-Si) utilisé largement pour le solaire PV. Ce travail de recherche vise à comprendre l'influence des germes et des conditions de croissance sur les lingots HPmc-Si (structure de grains, dislocations, impuretés et propriétés PV). Cinq lingots ont été élaborés par solidification dirigée. Pour l’un d’entre eux, deux types de germes ont été utilisés. Les caractéristiques de la région de croissance initiale (jusqu’à 50 mm) sont directement liées aux propriétés de la couche de germes. Or, celle-ci dépend à la fois des types de germes utilisés et des paramètres de l’étape de fusion. Les paramètres de croissance prennent le contrôle de la structure de grains après la région affectée par la couche initiale de germes. Cependant, les paramètres de croissance étudiés modifient peu les caractéristiques entre lingots HPmc-Si et le rendement de conversion des cellules solaires. Les zones de faible durée de vie des porteurs minoritaires déterminent le rendement de conversion et peuvent être principalement associées aux défauts structuraux et à la taille du grain, en plus des impuretés métalliques. La compétition des grains est un phénomène dynamique qui permet la disparition de certains grains défectueux pendant la croissance et surtout le maintien d’une taille de grains et homogène. Cette homogénéité obtenue pour la gamme de paramètres étudiée est une des caractéristiques principales des lingots HPmc-Si / Among new bulk silicon PV materials, HPmc-Si is one to be considered due its higher conversion efficiency compared to mc-Si solar PV. This research work aims at understanding the influence of the seeding materials and growth conditions on HPmc-Si ingots (dislocations and impurities). Five ingots were grown, and two types of seeding materials are compared to study the grain structure, the electrical properties and the conversion efficiency of solar cells. The initial growth region up to 50 mm is directly linked to the seed layer properties which are dependent on the melting segment parameters. The growth parameters take control on the grain structure after the seed affected region. The growth parameters studied modify little the characteristics of HPmc-Si ingots and the solar cell conversion efficiency. Low carrier lifetimeareas determine the conversion efficiency and they can mainly be associated to the grain size, besides metallic impurities. The grain competition is very dynamic to suppress defective grains and to maintain smaller grain size variation, homogeneous grain size and properties being the most important characteristic of HPmc-Si ingots

Visualization of glyphs has a long history in medical imaging but gains much more power when the glyphs are properly placed to fill the screen. Glyph packing is often performed via an iterative approach to improve the location of glyphs. We present an alternative implementation of glyph packing based on a Delaunay triangulation to speed up the clustering process and reduce costs for neighborhood searches. Our approach does not require a re–computation of acceleration structures when a plane is moved through a volume, which can be done interactively. We provide two methods for initial placement of glyphs to improve the convergence of our algorithm for glyphs larger and glyphs smaller than the data set’s voxel size. The main contribution of this paper is a novel approach to glyph packing that supports simpler parameterization and can be used easily for highly efficient interactive data exploration, in contrast to previous methods.

There is growing interest in the development of biomimetic matrices that are simultaneously cell-friendly, allow rapid vascularization, exhibit enough mechanical integrity to be comfortably handled and resist mechanical stresses when implanted in the site of interest. Meeting all these requirements with a single component material has proved to be very challenging. The hypothesis underlying this work was that hybrid materials obtained by combining scaffolds with bioactive hydrogels would result in a synergy of their best properties: a construct with good mechanical properties, easily handled and stable thanks to the scaffold; but also, because of the gel, cell-friendly and with enhanced oxygen and nutrients diffusion, and promoter of cell colonization. Moreover, such a composite material would also be useful as a controlled release system because of the gel’s incorporation. Poly (ethyl acrylate) (PEA) scaffolds prepared with two different morphologies were envisaged to provide the mechanical integrity to the system. Both types of scaffolds were physicochemically characterized and the effect of the scaffolds production process on the PEA properties was examined. The scaffolds preparation methods affected the PEA properties; nevertheless, the modifications induced were not detrimental for the PEA biological performance. Two different bioactive gels were studied as fillers of the scaffolds’ pores: hyaluronan (HA), which is a natural polysaccharide, and a synthetic self-assembling peptide, RAD16-I. HA is ubiquitously present in the body and its degradation products have been reported to be angiogenic. RAD16-I is a synthetic polypeptide that mimics the extracellular matrix providing a favourable substrate for cell growth and proliferation. Given the hydrophobic nature of poly(ethyl acrylate), the combination of PEA scaffolds with aqueous gels raised a number of problems regarding the methods to combine such different elements, the ways to gel them inside the pores, and the procedures to seed cells in the new composite materials. Different alternatives to solve these questions were thoroughly studied and yielded protocols to reliably obtain these complex structures and their biohybrids. An extensive physico-chemical characterization of the components’ interaction and the combined systems was undertaken. As these materials were intended for cardiac tissue engineering applications, the mechanical properties and the effect of the fatigue on them were studied. The different composite systems here developed were homogeneously filled or coated with the hydrogels, were easy to manipulate, and displayed appropriate mechanical properties. Interestingly, these materials exhibited a very good performance under fatigue. The use of the composite systems as a controlled release device was based on the possibility of incorporating active soluble molecules in the hydrogel within the pores. A release study of bovine serum albumin (BSA), intended as a model protein, was performed, which served as a proof of concept. The biological performance of the hybrid scaffolds was first evaluated with fibroblasts to discard the materials cytotoxicity and to optimize the cell seeding procedure. Subsequently, human umbilical vein endothelial cells (HUVECs) cultures were performed for their interest in angiogenic and vascularization processes. Finally, co-cultures of HUVECs with adipose-tissue derived mesenchymal cells (MSCs) were carried out. These last cells are believed to play an important role for clinical regenerative medicine, and their cross-talk with the endothelial cells enhances the viability and phenotypic development of HUVECs. Through the different experiments undertaken, hybrid scaffolds exceeded the outcome achieved by bare PEA scaffolds. / Arnal Pastor, MP. (2014). New scaffolding materials for the regeneration of infarcted myocardium [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/46129 / TESIS / Premios Extraordinarios de tesis doctorales

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This work has examines the creation and use of chemical templates for nanocircuit and other nanodevice fabrication. Chemical templating can be useful in attachment, orientation and wiring of molecularly templated circuits. DNA origami provides a suitable method for creating molecularly templated circuits as DNA can be folded into complex shapes and functionalized with active circuit elements, such as semiconducting nanomaterials. Surface attachment of DNA origami structures can be accomplished by hybridization of dangling single-stranded DNA (ssDNA) on the origami structures with complementary surface-bound strands. Chemical templating provides a pathway for placing the patterned surface-bound attachment points needed for surface alignment of the molecular templates. Chemical templates can also be used to connect circuit elements on the surface by selectively metallizing the templates to form local wiring. AFM tip-directed nano-oxidation was selected as the method for patterning to create chemical templates. This project demonstrates new techniques for creating, continuous metallization of, and DNA attachment to nanochemical templates. Selective-continuous metallization of nanochemical templates is needed for wiring of circuit templates. To improve the metallization density and enable the continuous nano-scale metallization of amine-coated surfaces, the treatment of amine-coated surfaces with a plating additive prior to metallization was studied. The additive treatment resulted in a 73% increase in seed material, enabling continuous nano-scale metallization. A new method was developed to create amine nanotemplates by selective attachment of a polymer to surface oxide patterns created by nano-oxidation. The treatment of the templates with the additive enabled a five-fold reduction in feasible width for continuous metallization. Nano-oxidation was also used in the nanometer-scale patterning of a thiol-coated surface. Metallization of the background thiols but not the oxidized patterns resulted in a metal film that was a negative of the patterns. The resulting metal film may be useful for nanometer-scale pattern transfer. DNA-coated gold nanoparticles (AuNPs) were selectively attached to amine templates by an ionic interaction between the template and ssDNA attached to the particles. Only the ssDNA on the bottom of the AuNPs interacted with the template, leaving the top strands free to bind with complementary ssDNA. Attempts to attach origami structures to these particles were only marginally successful, and may have been hindered by the presence of complementary ssDNA in solution but not attached to the origami, or the by the low density of DNA-AuNPs attached to the templates. The formation of patterned binding sites by direct, covalent attachment of ssDNA to chemical templates was also explored. Initial results indicated that ssDNA was chemically bound to the templates and able to selectively bind to complementary strands; however, the observed attachment density was low and further optimization is required. Methods such as these are needed to enable nano-scale, site-specific alignment of nanomaterials.