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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.
351

Efeito de brassinosteróide no crescimento, metabolismo e fixação de nitrogênio em plantas de Cajanus cajan noduladas e sob estresse salino / Effect of brassinosteroid on growth, metabolism and nitrogen fixation in Cajanus cajan nodulated plants, under salt stress

Longatti, Claudia Aparecida, 1970- 21 August 2018 (has links)
Orientador: Marlene Aparecida Schiavinato / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T08:53:28Z (GMT). No. of bitstreams: 1 Longatti_ClaudiaAparecida_M.pdf: 1449126 bytes, checksum: be3aefaf910ddbe46531e367581164f3 (MD5) Previous issue date: 2012 / Resumo: O metabolismo geral de uma planta pode ser afetado pelo excesso de sais no solo, visto que a salinidade pode causar reduções no crescimento e acelerar a senescência. Os brassinosteróides são hormônios vegetais envolvidos no aumento da tolerância a vários tipos de estresses, inclusive o estresse salino. Com o objetivo de avaliar a influência da aplicação de brassinosteróide no crescimento e metabolismo do nitrogênio em plantas de Cajanus cajan sob diferentes condições de estresse salino, plantas noduladas de C. cajan foram cultivadas em casa de vegetação na ausência ou presença de brassinosteróide (24-epibrassinolídeo), sob diferentes concentrações de NaCl (0 mM, 100 mM e 200 mM). A salinidade afetou o crescimento, reduzindo a área, o comprimento do caule, a longevidade foliar, o teor de umidade de folhas, caules e raízes, bem como a atividade da nitrogenase, os teores de pigmentos fotossintetizantes, de malondialdeído e de nitrogênio total em folhas verde maduras, e a proficiência e eficiência do uso de nitrogênio. A aplicação de brassinosteróide amenizou o efeito do NaCl nas reduções da área foliar e teores de clorofila a e total. Também atenuou o efeito do estresse salino na atividade da nitrogenase. Esse efeito positivo do brassinosteróide sobre a atividade da enzima refletiu-se no aumento da concentração de compostos nitrogenados nas folhas verde-maduras e reduziu, ainda, a perda de N nas folhas senescentes. A maior concentração de N total nas folhas verde-maduras de plantas tratadas com o 24-epibrassinolídeo levou à redução da eficiência de utilização desse elemento / Abstract: The general metabolism of a plant can be affected by salinity excess in soil, due to the fact that salinity can cause growth reduction and accelerate senescence. The brassinosteroids are plant hormones involved in increasing tolerance in several types of stress, including salt stress. In order to verify the influence of the application brassinosteroid on development and nitrogen metabolism in Cajanus cajan plants under different levels of salt stress, nodulated plants of C. cajan were cultivated in the greenhouse in the absence or presence of 24-epibrassinolide, under different concentrations of NaCl (0 mM, 100 mM and 200 mM). Salinity affected growth reducing leaf area, branch length, leaf longevity, moisture content of leaves, stems and roots, as well as activity of nitrogenase, amounts of photosynthetic pigments, malondialdehyde and total nitrogen in mature green leaves; nitrogen use proficiency and efficiency. The application of brassinosteroid attenuated the effect of NaCl on the leaf area and on the concentrations of chlorophyll a and total chlorophyll. The hormone also attenuated the effect of salt stress on the activity of nitrogenase. The positive effect of the hormone on the activity of the enzyme led to an increase in the concentration of nitrogenous compounds in the mature green leaves and reduced the lost of nitrogen in senescent leaves. The higher concentration of total nitrogen in mature green leaves of the plants treated with 24-epibrassinolide led to a reduction in nitrogen use efficiency / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal
352

Ontogenetic variations in leaf traits of the homoblastic species Dipterocarpus alatus under two light conditions at Cat Tien national park, Vietnam / Variations ontogénétiques de traits foliaires de l'espèces homoblastic Dipterocarpus alatus sous deux conditions lumineuses au parc national de Cat Tien, Vietnam

Dang Le, Anh Tuan 21 December 2012 (has links)
Contexte et objectifs : Les tentatives pour expliquer les variations des paramètres foliaires fondées uniquement sur les facteurs environnementaux, ce qui conduira à des erreurs importantes si la plante montre des variations ontogénétiques substantielles des propriétés foliaires. Nous avons évalué les variations des 27 traits morpho-anatomiques des feuilles de Dipterocarpus alatus durant six stades de développement architectural et entre les axes à un stade de développement donné sous deux conditions lumineuses différentes.Méthodologies:Une analyse architecturale a été réalisée pour distinguer précisément et objectivement des catégories d'axes et stades de développement de Dipterocarpus alatus. Les feuilles ont été collectées sur l'unité de croissance plus récente et complète sur la partie supérieure du tronc et sur la partie plus externe de la branche du milieu couronne des arbres qui poussent sous deux différentes conditions lumineuses. Vingt-deux traits foliaires ont été mesurées et calculées sur des images de tracés feuilles et de sections transversaux à l'aide de logiciel ImageJ. Densité stomatal a été calculée sur l'impression de vernis à ongles de la surface inférieure des feuilles. Quatre traits de chlorophylle ont été déterminées. Les tests d'ANOVA et Tukey ont été utilisés pour déterminer les différences entre les stades de développement et des axes. La contribution relative lmg a été calculée avec package R relaimpo et comparées avec l'analyse bootstrap pour déterminer le stade ontogénétique, catégorie axe ou l'intensité lumineuse, ce qui est expliqué plus les variations de l'anatomie des feuilles.Résultats:La morphologie et l'anatomie des feuilles diffère fortement durant l'ontogenèse pour les quatre axes en terme d'ordre et de catégorie deux sous des conditions lumineuses. L'effet de l'axe a été présentée au stade B, C, D et F, mais ont tendance à être insignifiante au stade E. Ontogenèse de l'arbre expliqué plus de variations dans la morphologie des feuilles et de l'anatomie que l'intensité lumineuse. Catégorie d'axe expliqué plus de variations dans la morphologie des feuilles, mais pas dans l'anatomie des feuilles que l'ontogenèse de l'arbre. Conclusions:Fortes et significatives variations intra-spécifiques (pendant l'ontogenèse et entre axes) peuvent influencer les variations inter-spécifiques, et donc contestent la validité de la valeur moyenne des traits foliaires entre les espèces. Ontogenèse de l'arbre contribué plus que l'intensité de la lumière dans l'explication de la variabilité dans la morphologie et l'anatomie des feuilles à la fois sur le tronc et deuxième l'ordre l'axe recommande fortement que les études sur les réponses de la morphologie et l'anatomie des feuilles à l'environnement doivent corriger l'effet de l'ontogenèse. / Background and Aims:Attempts to explain variations in leaf parameters based solely on environmental factors, this will lead to significant errors if the plant shows substantial ontogenetic variations in leaf properties. We evaluated variations in 27 morpho-anatomical leaf traits of Dipterocarpus alatus over six architectural development stages and between axes at a given development stage under two different light conditions. Methods:An architectural analysis was conducted to distinguish precisely and objectively axis categories and developmental stages of Dipterocarpus alatus. Leaves were collected on the most recent complete growth unit on the top of the trunk and the outermost part of the middle-crown branch with branchlet and twig from trees growing under two different light conditions. Twenty two leaf traits were measured and calculated using ImageJ on images of leaf tracings and cross-sections. Stomatal density was calculated on nail varnish impression of the leaf lower surface. Four chlorophyll traits were determined. One-way ANOVA and Tukey post-hoc tests were used to determine differences between development stages and axes. The lmg relative contribution was calculated with R package relaimpo and compared with bootstrap analysis to determine ontogenetic stage, axis category or light intensity, which explained more the variations in leaf anatomy.Key results:Leaf morphology and anatomy differed strongly during ontogeny for all four axes in term of order and category under both light conditions. The axis effect was displayed at stages B, C, D and F but tend to be insignificant at stage E. Tree ontogeny explained more variations in leaf morphology and anatomy than light intensity. Axis category explained more variations in leaf morphology but not in leaf anatomy than tree ontogeny. Conclusions: Strong and significant intraspecific variations (during ontogeny and between axes) may influence the interspecific variations, and thus challenge the validity of the mean value of leaf traits between species. Tree ontogeny contributed more than light intensity in explanation of the variability in leaf morphology and anatomy both on the trunk and second axis order strongly recommends that studies on the responses of leaf anatomy to the environment need to correct for the ontogeny effect.
353

Ecofisiologia e morfoanatomia de herbáceas em florestas secas em regeneração.

SILVA, Bárbara Laine Ribeiro da 01 April 2016 (has links)
Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-06-09T18:33:27Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Bárbara Laine Ribeiro da Silva.pdf: 2635614 bytes, checksum: 8384212e8db84a27bc2b1fd6a579e7ad (MD5) / Made available in DSpace on 2017-06-09T18:33:27Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Bárbara Laine Ribeiro da Silva.pdf: 2635614 bytes, checksum: 8384212e8db84a27bc2b1fd6a579e7ad (MD5) Previous issue date: 2016-04-01 / CAPES / Em ambientes com clima semiárido, a sobrevivência das plantas depende da adaptação de características morfológicas, anatômicas e fisiológicas. O hábito das espécies e a estrutura do ambiente no qual a planta está inserida também determina sua sobrevivência em ambientes com condições ambientais limitantes, como a caatinga. No caso das espécies herbáceas, é necessário descobrir qual a principal limitação ambiental para o seu desenvolvimento, já que a maioria delas possui ciclo de vida restrito ao período de chuvas na região, bem como quais são as características desenvolvidas que permitem sua sobrevivência no ambiente. O trabalho avaliou características fisiológicas, anatômicas e morfológicas de três espécies herbáceas (Hyptis suaveolens L., Stachytarpheta sanguinea Mart. ex Schauer e Jacquemontia evolvuloides (Moric.) Meisn., em áreas de caatinga com 22, 44 e mais de 60 anos de regeneração, na Paraíba. Foram analisadas: área foliar; área foliar específica; espessura das epidermes, das cutículas, dos parênquimas e do mesofilo; densidade estomática e de tricomas; concentrações de clorofila a, clorofila b e carotenoides; potencial hídrico foliar, trocas gasosas, concentrações de compostos fenólicos totais, nitrogênio, potássio e fósforo. As três espécies apresentaram características anatômicas de folhas de sol, com estômatos e tricomas em ambas as faces foliares e maior concentração na face abaxial. J. evolvuloides apresentou mais características de locais ensolarados, com a menor área foliar específica na área em regeneração mais recente, maior espessura de epiderme e parênquima isobilateral. Algumas variações morfoanatômicas entre as áreas foram comuns entre as três espécies, como as maiores espessuras dos mesofilos e dos parênquimas na caatinga mais antiga que nas áreas com 22 e 44 anos em regeneração. No geral, H. suavoelens e S. sanguinea foram espécies mais plásticas que J. evolvuloides, com as maiores diferenças morfofisiológicas entre as áreas. J. evolvuloides demonstrou ser mais adaptada à baixa disponibilidade hídrica e à alta incidência luminosa. / In environments with semi-arid climate, the survival of plants depends on the adaptation of morphological, anatomical and physiological characteristics. The habit of the species and environmental structure in which the plant is inserted, also determines their survival in environments with limiting environmental conditions, such as the caatinga. In the case of herbaceous species, it is necessary to find out what is the main environmental limitations for its development, since most they have a life cycle restricted to the rainy season in the region, and what are the features developed to survival in the environment. This work determined the physiological, anatomical and morphological characteristics of three herbaceous species (Hyptis suaveolens L. Stachytarpheta sanguinea Mart. Ex Schauer and Jacquemontia evolvuloides (Moric.) Meisn., in areas of caatinga with 22, 44 and over 60 years of regeneration, in Paraiba state. Were analyzed the leaf area, specific leaf area, thickness of the epidermis, cuticle, parenchyma and mesophyll, the stomata and trichomes densities; concentrations of chlorophyll a, chlorophyll b and carotenoids, the leaf water potential, gas exchange, concentrations of total phenolic compounds, nitrogen, potassium and phosphorus. The three species have anatomical features of sun leaves with stomata and trichomes in both leaf surfaces and a greater concentration on the abaxial surface. J. evolvuloides showed more characteristics of sunny locations, with lowest specific leaf area in the most recent regeneration area, thickest epidermis and isobilateral parenchyma. Some morphoanatomical variations between the areas were common among the three species, such as the greater thicknesses of mesophyll and parenchyma in the oldest caatinga than in the areas with 22 and 44 years in regeneration. Overall, H. suavoelens and S. sanguinea were more plastic species than J. evolvuloides, with the largest morphophysiological differences between areas. J. evolvuloides proved to be more acclimatized to low water availability and high light incidence.
354

Vliv anatomické struktury na optické vlastnosti listu vybraných dřevin - vztah k vodnímu režimu. / The effect of leaf structure on the leaf optical properties - Implication for water regime.

Neuwirthová, Eva January 2015 (has links)
Due to coal mining activities, heap substrates rich in clays with poor water permeability and lack of nutrients are relocated outside of mines representing hostile environment to the majority of vegetation. A material from the surface coal mines in Sokolov forming the Velká Podkrušnohorská Heap (VPS) form large locality showing characteristics of anthropogenically devasted landscape. The aim of the present study was to compare leaf structural and biochemical parameters with relation to a leaf reflectance of two pioneer tree species Salix caprea and Populus tremula with regard to leaf water regime and leaf adaptation to a water loss. From the methodological point of view, the study aimed on contribution to determine relation of selected leaf structural parameters to leaf reflectance what has not been intensively studied yet. The foliage of trees P. tremula and S. caprea grown on succession localities S2 a S3 for 30 years was used as a material for my study. The material was studied for its structure using the leaf cross sections nd abaxial epidermal strips (thickness of the leaf tissue layers and of a leaf, stomatal size density and area). Other studied parameters were contents of photosynthetic pigments, specific leaf area (SLA), water potential and leaf reflectance in regions of photosyntetically...
355

Automated In-Field Leaf-Level Hyperspectral Imaging of Corn Plants Using a Cartesian Robotic Platform

Ziling Chen (8810570) 21 June 2022 (has links)
Agriculture-related industry and academia have widely adopted Hyperspectral Imaging (HSI) based in-field phenotyping activities. Current HSI solutions such as airborne remote sensing platforms and handheld spectrometers have been proven effective and have become popular in various phenotyping applications. However, the quality of remote sensing systems suffers from a low signal-over-noise ratio due to the imaging distance and low resolution. Handheld leaf spectrometers are slow, labor-intensive, and only measure a small spot on the leaf, which fails to represent the canopy variation. In 2018, the Purdue ABE sensor lab developed a new handheld hyperspectral leaf imager, LeafSpec. For the first time, field phenotyping researchers were able to collect high-resolution leaf hyperspectral images without the negative impacts of ambient lighting and leaf-slope angle changes. LeafSpec has been successfully tested in field assays and showed its advantageous phenotyping quality. The goal of this study was to test the hypothesis that a robotic system could replace the human operator required to perform in-field and leaf-level HSI using LeafSpec. The system consisted of a modified version of the LeafSpec device, a machine vision system for target leaf detection, a National Instrument MyRIO as a controller and a customized cartesian robotic arm with five Degrees of Freedom (DOF). For each scan, the on-board machine vision system recognized the top leaf collar and obtained the target coordinates. The coordinates were then passed to the controller, which calculated the appropriate path and acceleration profile and drove the arm to approach the target leaf and scan the leaf with the LeafSpec device. The scanned image was then processed in real-time to calculate plant physiological features such as chlorophyll content, nitrogen content and so on. In the 2019 field test, the designed system collected data from 41 corn plants with two genotypes and three levels of nitrogen treatments with an average cycle time of 86 seconds. The nitrogen content predicted by the designed system had an R squared of 0.72 with the ground truth. The developers, therefore, concluded that the robotic gantry system was capable of replacing human operators for LeafSpec hyperspectral corn leaf imaging in the field with high quality.
356

Effect of the moisture heterogeneity of leaf litter layer on temporal and spatial variation in the litter heterotrophic respiration in a warm-temperate forest / 暖温帯林の落葉層における水分の不均質性が落葉分解呼吸の時空間変動に与える影響

Ataka, Mioko 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19032号 / 農博第2110号 / 新制||農||1031(附属図書館) / 学位論文||H27||N4914(農学部図書室) / 31983 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 谷 誠, 教授 北山 兼弘, 教授 本田 与一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
357

Bioinspired Smart Surfaces with Switchable Wetting Properties for Droplet Manipulation and Controlled Drug Release

Qi, Lin 17 June 2019 (has links)
No description available.
358

Understanding the multiple resource needs of leaf-cutter bees to inform pollinator conservation and the restoration of reclaimed mines

Ballas, John Peter, II 24 September 2020 (has links)
No description available.
359

The Effect of Mid-season Foliar Fungicide and Insecticide, Applied Alone or in Combination, on Soybean Yield in Ohio

Ng, Sin Joe 30 August 2017 (has links)
No description available.
360

Prevalensen och kännedomen om relativ energibrist bland kvinnliga idrottare oavsett idrottslig nivå : Tvärsnittsstudie

Karlsson, Ann-Louis January 2022 (has links)
Bakgrund: Relative energy deficiency in sports (RED-S) är ett syndrom som förekommer inom många idrotter och olika idrottsliga nivåer. Konsekvenserna av detta syndrom är mångfacetterad, det kan påverka prestationen långsiktigt och kan orsaka skador och avslut på idrottskarriären. I forskningen är idrotter såsom löpning, estetiska idrotter och friidrottare de som är överrepresenterade i förhållande till RED-S. Kvinnor är generellt en underrepresenterad grupp inom idrottsmedicinsk forskning och detta motiverar till att studera just denna grupp.  Syfte: Syftet med denna undersökning var att undersöka i vilken utsträckning respondenterna hört talats om RED-S, samt att identifiera riskgrupper utifrån träningsmängd och idrottsutförande hos idrottande kvinnor inom fotboll, innebandy, friidrott och ridning, oavsett idrottslig nivå. Metod: Data insamlades med hjälp av en digitalbaserad enkät som besvarades av 44 deltagare. Enkäten bestod av 35 frågor och distribuerades i en sluten grupp som bestod av 16 000 + medlemmar samt en öppen grupp med 3 000 medlemmar och även via egna sociala medier. Resultat: Av totalt 44 deltagare fick 24 deltagare en poäng ≥8 utifrån frågeformuläret Low Energy availability in females questionnaire (LEAF-Q), enligt enkätens poängssystem indikerar detta en förhöjd risk att utveckla RED-S. Den överrepresenterade idrotten var ridsporten med 22 deltagare. Den ojämna fördelningen gjorde det svårt att generalisera några resultat för träningsmängd och idrottskategori. Av totalt 44 deltagare var det endast sex deltagare som tidigare hade hört talats om RED-S i utbildningssyfte.  Diskussion: Mer än 50% av deltagarna hade en LEAF-Q poäng högre ≥8 och majoriteten var användare av någon form av preventivmedel vilket påverkade det slutgiltiga resultatet.  Konklusion: Av cirka 19 000 potentiella deltagare var det 44 svaranden, bortfallet var högt vilket innebär att resultatet blev missvisande. Det tenderar att finnas ett kunskapsglapp bland kvinnliga idrottare vad gäller kännedom om syndromet RED-S. Trots att resultatet av denna undersökning inte går att generalisera på en större population så finns det andra studier som indikerar liknande resultat. / Background: Relative energy deficiency in sports (RED-S) is a syndrome that occurs in many sports and different sports levels. The consequences of this syndrome are multifaceted, it can affect performance in the long term and can cause injuries and the end of the sports career. In the research, sports such as running, aesthetic sports and track and field athletes are those that are overrepresented in relation to RED-S. Women are generally an underrepresented group in sports medicine research and this motivates to study this particular group. Purpose: The purpose of this survey was to investigate the extent to which the respondents had heard about RED-S, and to identify risk groups based on the amount of training and sports performance of female athletes in football, floorball, athletics and horse riding, regardless of the level of sport. Method: Data were collected using a digital-based questionnaire that was answered by 44 participants. The survey consisted of 35 questions and was distributed in a closed group consisting of 16,000+ members as well as an open group with 3,000 members and via own social media. Results: Out of a total of 44 participants, 24 participants received a score ≥8 based on the Low Energy availability in females questionnaire (LEAF-Q), according to the questionnaire's scoring system, this indicates an increased risk of developing RED-S. The over-represented sport was equestrian with 22 participants. The uneven distribution made it difficult to generalize any results for training amount and sport category. Out of a total of 44 participants, only six participants had previously heard of RED-S for educational purposes. Discussion: More than 50% of the participants had a LEAF-Q score higher than ≥8 and the majority were users of some form of contraception, which affected the result. Conclusion: Out of approximately 19,000 potential participants, there were 44 respondents, the dropout rate was high, which means that the results were misleading. There tends to be a knowledge gap among female athletes in terms of awareness of RED-S syndrome. Although the results of this study cannot be generalized to a larger population, there are other studies that indicate similar results.

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