<div><p>Wheat is among the most important cereal crops in the world today with respect to the area harvested (219 million ha), production (772 million tonnes), and productivity (3.53 tons/ha). However, global wheat production goals for the coming decades are falling short of needed increases. Among the leading factors hindering yields is abiotic stress which is present in nearly 38% of wheat acres globally. Nevertheless, many standard wheat breeding programs focus on yield and yield related traits (i.e. grain yield, plant height, and test weight) in ideal environments rather than evaluating traits that could lead to enhanced abiotic stress tolerance. In this thesis, we explore the use of root and high-throughput phenotyping strategies to aid in further development of abiotic stress tolerant varieties. </p><p>In the first three experiments, root phenotypes were evaluated in two nitrogen (N) treatments. Over a series of seedling, adult, and multiple-growth-stage destructive plant biomass measurements, above-ground and below-ground traits were analyzed in seven geographically diverse wheat accessions. Root and shoot biomass allocation in fourteen-day-old seedlings were analyzed using paper-roll-supported hydroponic culture in two Hoagland solutions containing 0.5 (low) and 4.0 (high) mM of N. Root traits were digitized using a WINRhizo platform. For biomass analysis at maturity, plants were grown in 7.5-liter pots filled with soil mix using the same concentrations of N. Traits were measured as plants reached maturity. In the third N experiment, above- and below-ground traits were measured at four-leaf stage, stem elongation, heading, post-anthesis, and maturity. At maturity, there was a ~15-fold difference between lines with the largest and smallest root dry matter. However, only ~5-fold difference was observed between genotypes for above-ground biomass. In the third experiment, root growth did not significantly change from stem elongation to maturity. </p><p>In the final experiment, two of these lines were selected for further evaluation under well-watered and drought treatments. This experiment was implemented in a completely randomized design in the Controlled Environment Phenotyping Facility (CEPF) at Purdue University. The differential water treatments were imposed at stem elongation and continued until post-anthesis, when all plants were destructively phenotyped. Image-based height and side-projected area were associated with height and shoot dry matter with correlations of r=1 and r=0.98, respectively. Additionally, 81% of the variation in tiller number was explained using convex hull and side-projected area. Image-based phenotypes were used to model crop growth temporally, through which one of the lines was identified as being relatively more drought tolerant. Finally, the use of the Munsell Color System was explored to investigate drought response.</p><p>These experiments illustrate the value of phenotyping and the use of novel phenotyping strategies in wheat breeding to increase adaptation and development of lines with enhanced abiotic tolerance.</p></div><br>

A Neurobiologia Vegetal é um recente ramo das ciências vegetais que objetiva esclarecer os complexos padrões de comportamento vegetal, no que se refere à percepção, processamento, armazenamento e transmissão de sinais na planta e entre plantas. A detecção de vizinhos, é uma capacidade que implica em auto reconhecimento, uma vez que um organismo só terá sucesso em interações competitivas se for capaz de auto/não-auto discriminação. Assim, objetivou-se com este trabalho verificar se raízes de ervilha (Pisum sativum) cv. Mikado apresentam crescimento diferenciado quando na presença de raízes da mesma planta, e de raízes de outras plantas, mas pertencentes ao mesmo genótipo, para que se possa averiguar sua capacidade de auto/não-auto discriminação. Além disso, avaliou-se também o crescimento da parte aérea para observar em que grau a presença de plantas vizinhas pode influenciar o desenvolvimento vegetativo de plantas de ervilha. Quatro dias após a germinação, plântulas de Pisum sativum cv. Mikado tiveram a raiz principal cortada 5 mm abaixo do hipocótilo. Passados sete dias, foram retiradas as raízes secundárias, deixando-se apenas duas raízes, de igual tamanho, por planta (split-root). Plantas com duas raízes iguais foram replantadas, com cada vaso contendo duas raízes da mesma planta (tratamento Auto) ou duas raízes de plantas diferentes (Tratamento Não-auto). Os vasos foram agrupados em tríades. O experimento foi mantido em estufa incubadora sob condições de temperatura e fotoperíodo controladas e após 18 dias foram feitas avaliações do crescimento da parte aérea e das raízes, através das medições de: altura da planta (cm), peso fresco de parte aérea e de raiz (g), peso seco de parte aérea e de raiz (g), área foliar (cm2), área radicular (cm2), comprimento total de raiz (cm) e diâmetro médio de raiz (cm). A análise dos dados considerando os valores médios de cada tríade revelou não haver diferença significativa entre os tratamentos Auto e Não-auto com relação ao crescimento de parte aérea. No que se refere ao crescimento da raiz, com exceção do diâmetro médio, as demais variáveis diferiram significativamente, sendo que as plantas pertencentes ao tratamento Auto apresentaram valores de peso seco, área superficial e comprimento total 36,71%, 27,84% e 23,18%, respectivamente, maiores do que as plantas do tratamento Não-auto. Ou seja, as plantas que não estavam sob competição apresentaram maior crescimento de raiz. No entanto, quando se observou o comportamento das plantas entre si, em cada tríade, verificou-se, no tratamento não-auto, diferenças visíveis de crescimento tanto em parte aérea como na raiz entre as três plantas que constituía cada tríade. Verificou-se também que a raiz de uma mesma planta cresceu diferentemente de acordo com a identidade da raiz vizinha. Enquanto que no tratamento auto as três plantas que constituíam uma tríade tinham aproximadamente o mesmo tamanho de parte aérea e raiz. Assim, podemos afirmar que o crescimento das plantas no tratamento não-auto foi influenciado pelas interações entre as raízes e mais que isto, foi dependente da identidade da raiz vizinha implicando em auto/não-auto discriminação e reconhecimento parental. / The Plant Neurobiology is a recent branch of plant science that aims to clarify the complex patterns of behavior vegetable, with respect to perception, processing, storage and transmission of signals in plant and between plants. The detection of neighbors, is a capacity that involves self-recognition and an individual will only be successful in competitive interactions if it is capable of self/non-self discrimination. Thus, the objective was to determine whether roots of pea (Pisum sativum) cv. Mikado grow differently in the presence of the same plant roots, and roots of other plants, but within the same genotype, so that we can determine its capacity for self/non-self discrimination. In addition, we assessed also the growth of the shoot to see to what degree the presence of neighboring plants can influence the vegetative growth of pea plants. Five days from germination, seedlings of Pisum sativum cv. Mikado had the seminal root severed 5 mm below the hypocotyl. After seven days, all but two of these roots were removed, leaving only two roots of equal size per plant (split-root). Plants with two equal roots were replanted, with each pot containing two roots of the same plant (treatment self) or two roots of different plants (Treatment non-self). Pots were grouped in triplets. The experiment was kept in an incubator camera under controlled conditions of temperature and photoperiod and after 18 days were evaluated for growth of shoots and roots. It was measure plant height (cm), fresh weight of shoot and root (g), dry weight of shoot and root (g), leaf area (cm2), root area (cm2), total length of root (cm) and average root diameter (cm). The analysis of data considering the average values of each triplets showed no significant difference between treatments self and non-self in relation to the growth of shoots. With respect to root growth, except for the diameter, the other variables differed significantly, and plants belonging to treatment self had values of dry weight, surface area and total length of 36.71%, 27.84 % and 23.18%, respectively, higher than the treatment plants non-self. That is, plants that were not under competition had higher root growth. However, when we observe the behavior of plants in each triplet, it was found that the treatment non-self, the plants had sizes of shoot and root differ. It was also found that the root of the same plant grew differently depending on the identity of neighboring roots. While in treatment self, the three plants that constituted a triplet had, approximately, the same size of shoot and root. Thus, we can say that the growth of plants to treatment non-self was influenced by the interactions between roots and more that this was dependent on the identity of neighboring roots implying self/non-self discrimination and kin recognition.

Este trabalho consiste de duas partes. Na primeira, desenvolvemos uma teoria de Nielsen equivariante para raizes de G-aplicações $f:X\\to Y$ equivariantes entre G-espaços topológicos Hausdorff, conexos, normais, localmente conexos por caminhos e semilocalmente simplesmente conexos, onde G é um grupo topológico, Na segunda parte, estudamos a questão da realização do G-número de Nielsen de raizes quando este é zero. / This work consists of two parts. In the firs one, we develop an equivariant Nielsen root theory for G-maps. We consider equivariant maps $f:X\\to Y$ between Hausdorff, connected, normal, locally path connected and semilocally simply connected G-spaces, where G is a topological group. In the second part, we study the question of the realization of G-Nielsen root number when it is zero.

O presente trabalho avaliou o efeito do tratamento da superfície radicular por meio da instrumentação com curetas, US e US seguido de curetas, utilizando dentes mineralizados e desmineralizados conjugando a utilização de cítrico e tetraciclina. As superfícies dentais foram analisadas em MEV por um único examinador, sendo utilizados 66 dentes unirradiculares com presença de cálculo indicando doença periodontal. Os dentes foram divididos em 6 grupos experimentais com 10 dentes cada e um grupo controle com 6 dentes sem tratamento. O protocolo de tratamento dos grupos seguiu a seguinte orientação: grupo 1- dentes mineralizados instrumentados com curetas; grupo 2- dentes mineralizados instrumentados com US; grupo 3- dentes mineralizados instrumentados com US, seguindo-se instrumentação com curetas; grupo 4- dentes instrumentados com curetas, desmineralizados e novamente instrumentados com curetas; grupo 5 - dentes instrumentados com US, desmineralizados e novamente instrumentados com US; e, grupo 6- dentes instrumentados com US, desmineralizados e novamente instrumentados com curetas. Foram analisadas a quantidade de cálculo residual (ICR), a rugosidade da superfície radicular (IRS) e perda da substância dentária (IPSD). Os resultados demonstraram diferenças estatísticas significativas quanto ao ICR do grupo 2 em relação aos grupos 3, 4 e 6 e do grupo 5 com os grupos 4 e 6; quanto ao IRS houveram diferenças estatísticas significativas entre o grupo 2 e os grupos 1, 4 e 6 e entre o grupo 5 e os grupos 1 e 6; quanto ao IPSD, observou-se que não houve diferenças estatísticas significativas entre os grupos. O uso de curetas isoladamente ou após US parece melhor se ajustar aos critérios de preparo adequado da raiz, em função dos parâmetros avaliados. / The present work aimed at evaluating the effect of root treatment by instrumentation of not only mineralized teeth with curettes, ultra-sonics (US) and US followed by curettes, but also of teeth intermediately demineralized in combined instrumentations, by using citric acid and tetracycline. The dental surfaces were analysed on SEM by a unique examiner, being utilized 66 uniradicular teeth presenting calculus and thus indicating periodontal disease. The teeth were divided into 6 experimental groups with 10 teeth each and a control group consisting of 6 teeth with no treatment. The treatment protocol for the groups was as follows: group 1- mineralized teeth instrumented with curettes; group 2- mineralized teeth instrumented with US; group 3- mineralized teeth instrumented with US, followed by curette; group 4 - teeth instrumented with curettes, demineralized and again instrumented with curettes; group 5 - teeth instrumented with US, demineralized and again instrumented with US; and, group 6- teeth instrumented with US, demineralized and instrumented with curettes. The amount of residual calculus (RCI), roughness of the radicular surface (SRI) and loss of dental substance (LTSI) were assessed. The results demonstrated statistically significant differences regarding the RCI of group 2 in relation to groups 3, 4 and 6, and that of group 5 with groups 4 and 6; as for the SRI, there were statistically significant differences between group 2 and groups 1, 4 and 6, and between group 5 and groups 1 and 6; no statistically significant differences were observed for the LTSI among groups. The use of curettes, alone or following US, seems more suitable for the criteria of adequate root preparation, as a function of the parameters evaluated.

Este estudo avaliou, por meio de cultivo celular e MEV, a capacidade de adesão de fibroblastos e as alterações estruturais ocorridas na superfície dentinária de reabsorções radiculares externas simuladas, após tratamento com hidróxido de cálcio, MTA e/ou radiação com laser de diodo de alta potência e laser Er:YAG. Após a hemisecção das raízes de 31 dentes unirradiculares, foram realizadas cavidades padronizadas no terço cervical de cada secção, obtendo-se 62 amostras que foram divididas em 9 grupos: grupo1 - irradiação com laser Er:YAG (42 mJ/pulso, 10 s, 10 Hz e 38 J/cm2 ); grupo 2 - irradiação com laser de diodo de alta potência (1 W, 10 s, 796 W/cm2); grupo 3 - preenchimento da cavidade com hidróxido de cálcio e irradiação com laser Er:YAG; grupo 4 - preenchimento da cavidade com hidróxido de cálcio e irradiação com laser de diodo; grupo 5 - preenchimento da cavidade com MTA e irradiação com laser de Er:YAG; grupo 6 - preenchimento da cavidade com MTA e irradiação com laser de diodo; grupo 7 - preenchimento da cavidade com hidróxido de cálcio; grupo 8 - preenchimento da cavidade com MTA e grupo 9 (controle) - nenhum tratamento. Após a esterilização dos espécimes foi realizado o subcultivo celular com fibroblastos gengivais da linhagem FMM1, o plaqueamento dos fragmentos (5 x 104 células por fragmento) e o preparo para análise em MEV. A contagem das células aderidas evidenciou que a adesão celular foi em ordem decrescente: G1 (Er:YAG) > G2 (diodo) > G9 (controle) > G8 (MTA) > G5 (MTA+Er:YAG) > G6 (MTA+diodo) > G4 (CaOH2+diodo) > G3 (CaOH2+Er:YAG) > G7(CaOH2). Observou-se diferença estatisticamente significante entre a maioria dos grupos experimentais, exceto entre os grupos: G9 x G8; G8 x G5; G8 x G4; G5 x G6; G4 x G3; G3x G7. Na análise em MEV, observou-se nas amostras irradiadas com laser Er:YAG microrugosidades na superfície dentinária, ausência de smear layer e túbulos dentinários abertos. As irradiadas com laser de diodo apresentaram superfície dentinária mais lisa, maior quantidade de smear layer e os túbulos dentinários fechados. Não foram observadas zonas de carbonização nos grupos irradiados com laser. Nos grupos nos quais se associou a radiação laser com os materiais de uso endodôntico, foram observadas zonas de derretimento e fusão nas superfícies do hidróxido de cálcio e do MTA. Diante dos resultados obtidos foi possível concluir que: a irradiação com os lasers Er:YAG e de diodo, nos arâmetros utilizados neste experimento, provocaram alterações morfológicas nas superfícies dentinárias das reabsorções simuladas que favoreceram a adesão celular; o uso do MTA nas reabsorções radiculares simuladas permitiu a adesão celular, enquanto que o hidróxido de cálcio a inibiu e a associação dos materiais de uso endodôntico com os lasers Er:YAG e de diodo resultou em alterações morfológicas na superfície do MTA, assim como, na do hidróxido de cálcio, que interferiram, de forma discreta, na adesão celular. / The present study, utilizing cell culture and SEM, evaluated the adhesion of fibroblasts, and the structural changes on the dentinal surface of simulated external root resorptions, after treatment with calcium hydroxide, MTA and/or high power diode laser radiation and Er:YAG laser radiation. After splitting the roots of 31 single rooted teeth, standardized cavities were done on the coronal third of each section, resulting in 62 samples which were divided into 9 experimental groups: group 1 ? Er:YAG laser irradiation (42 mJ/pulse, 10 Hz, 10 s, 38 J/cm2); group 2 ? high power diode laser irradiation (1 W, 10 s, 796 W/cm2); group 3 ? cavity filling with calcium hydroxide and Er:YAG laser irradiation; group 4 ? cavity filling with calcium hydroxide and irradiation with diode laser; group 5 ? cavity filling with MTA and Er:YAG laser irradiation; group 6 - cavity filling with MTA and irradiation with diode laser; group 7 - cavity filling with calcium hydroxide; group 8 - cavity filling with MTA and group 9 (control) ? not treated. After the specimens were sterilized, a subculture was done with gingival fibroblasts from cell line FMM1. The fragments were plated (5 x 104 per fragment) and then prepared for SEM analyzis. The counting of adhered cells showed that the cells? adhesion was in decreasing order: G1 (Er:YAG) > G2 (diode) > G9 (control) > G8 (MTA) > G5 (MTA+Er:YAG) > G6 (MTA+diode) > G4 (CaOH2+diode) > G3 (CaOH2+Er:YAG) > G7(CaOH2). Significant statistical differences were observed among most of the experimental groups, except among the following groups: G9 x G8; G8 x G5; G8 x G4; G5 x G6; G4 x G3; G3 x G7. At the SEM analyzis of the samples irradiated with Er:YAG laser, roughness on the dentinal surface, no smear layer and open dentinal tubules were observed. The samples irradiated with diode laser exhibited a smooth surface, more smear layer and closed dentinal tubules. No carbonization zones were observed at the groups irradiated with both lasers. In the groups where laser irradiation was associated with endodontic materials, melting zones and fusion on the calcium hydroxide and MTA surfaces were observed. Based on the results it may be concluded that: irradiation with Er:YAG and diode lasers, in the parameters utilized in this experiment, caused morphologic changes on the dentinal surfaces of the simulated resorptions that favored cell adhesion; the MTA used on the simulated root resorptions allowed cell adhesion while calcium hydroxide inhibited it; and, the association of the endodontic materials to Er:YAG and diode lasers resulted in morphologic changes on the MTA and on the calcium hydroxide surface, which interfered subtly with the cell adhesion.

O presente trabalho investigou microscopicamente o efeito da equistatina sobre o processo reabsortivo de dentes incisivos superiores de ratos, extraídos e reimplantados. Foram utilizados 42 animais, divididos em grupos com e sem equistatina. Os tempos extra-alveolares dos dentes foram de 30 e 60 minutos e os períodos experimentais pós-cirúrgicos foram 15, 60 e 90 dias. Os espécimes obtidos foram processados e corados em H.E. para observar os processos biológicos presentes. Os eventos microscópicos foram avaliados por dois examinadores, de modo quantitativo histomorfométrico e descritivo, de acordo com o tipo de infiltrado e intensidade da reação inflamatória; com o tipo, extensão e localização de reabsorção dentária; e presença de anquilose alveolodentária. O nível de concordância entre examinadores, determinado pelo índice Kappa, revelou-se quase perfeito para todas as variáveis avaliadas. A comparação entre os grupos testes e controle para as variáveis apresentadas foi feita por meio do teste Mann-Whitney e mostrou não haver diferença estatística entre a administração de equistatina e tempo extra-alveolar em relação à intensidade inflamatória nas diferentes porções radiculares. Quanto ao tipo de reabsorção estabelecida, notou-se que a presença de reabsorção inflamatória foi significativamente maior (p<0,05) no grupo controle nos tempos de 30 e 60 minutos no período pós-cirúrgico de 15 dias. A anquilose alveolodentária também esteve significativamente mais presente no grupo tratado com equistatina com 30 minutos extra-alveolar e 15 dias de período experimental. Houve, ainda, mais anquilose alveolodentária no grupo controle de 60 minutos extra-alveolar, com o período experimental de 60 dias. No período experimental de 90 dias todos os espécimes avaliados apresentaram processos reabsortivos inflamatórios e ausência de anquilose alveolodentária. O teste Kruskall-Wallis avaliou as diferenças significantes entre grupos, em relação à intensidade inflamatória por terço radicular, tipo de reabsorção e anquilose alveolodentária. As comparações individuais foram realizadas com teste Dunn e mostrou diferenças significantes entre grupos teste em relação ao período experimental. As variáveis testadas também foram avaliadas pelo teste de correlação de Spearman, que demonstrou haver correlações positivas substanciais ou muito fortes entre as variáveis: intensidade inflamatória no 1/3 cervical e no 1/3 médio, intensidade inflamatória no 1/3 cervical e no 1/3 apical e intensidade inflamatória no 1/3 médio e no 1/3 apical. Destacou-se ainda a correlação negativa substancial entre tipo de reabsorção e a intensidade inflamatória do 1/3 médio radicular. O uso de implantes de ELVAX com equistatina demonstrou possuir um potencial terapêutico na prevenção de processos reabsortivos inflamatórios no modelo experimental de reimplante de incisivos superiores murinos. / This study aimed to microscopically investigate the effect on the dental resorptive process of subgingival implants of ELVAX polymer with peptide echistatin in reimplantation of upper incisors in rats. For this purpose, 42 animals were used and divided into groups with and without echistatin. Extra alveolar socket period was 30 and 60 minutes and post-surgical experimental periods were 15, 60 and 90 days. Specimens were processed and stained with H.E. to observe the biological processes in the area. The microscopic events were evaluated by two examiners. Quantitative histomorphometric and descriptive evaluation of the events were performed according to the presence, type and location of the inflammatory response, incidence of resorptions or dental ankylosis. The level of agreement between examiners determined by the Kappa index, proved to be almost perfect for all variables. The comparison between the experimental and control groups for the variables presented was performed using the Mann-Whitney test and showed no statistical difference between the administration of echistatin and extra alveolar socket period relative to the inflammatory intensity in different portions of the root. Regarding the type of resorption established, it was noted that the presence of inflammatory resorption was significantly higher (p<0.05) in the control group on days 30 and 60 minutes in the postoperative period of 15 days. Dental ankylosis was also significantly more prevalent in the group treated with echistatin in extra alveolar socket period of 30 minutes and 15-day trial period. There was even more dental ankylosis in control group with 60 minutes of extra alveolar socket, with the trial period of 60 days. In the trial period of 90 days all specimens studied featured inflammatory resorptives processes and absence of dental ankylosis. The Kruskal-Wallis test assessed significant differences between groups in relation to the intensity of inflammation by root third, resorption type of and dental. Individual comparisons were performed with Dunn test and showed significant differences between groups in relation to the test observation period. The variables tested were also evaluated by Spearman correlation test, which showed that there are substantial or very strong positive correlations among the variables: intensity of inflammation in the cervical third and the medium third, intensity of inflammation in the cervical 1/3 and apical 1/3 inflammatory intensity in the middle 1/3 and apical 1/3. It also highlighted the significant negative correlation between type and intensity of inflammatory resorption of middle 1/3 root. The use of subgingival ELVAX implants with echistatin shown to have therapeutic potential in preventing the inflammatory resorptive process in the experimental model of reimplantation of upper incisors in rats.

Objetivou-se avaliar a influência do EDTA, laser de Nd:YAG e da combinação de ambos nas superfícies das paredes dentinárias e na obturação de canais laterais artificiais. Foram utilizados 54 pré-molares inferiores com 1 raiz e 1 canal radicular. Suas coroas foram removidas e três canais laterais artificiais foram confeccionados nos três terços de uma das faces proximais de cada uma dessas raízes com um alargador com diâmetro referente a uma lima do tipo K número 15. Preparado os canais laterais, os canais principais foram instrumentados com limas do tipo K no terço apical, até a de nº 40, e com brocas de Gattes Glidden nos terços cervical e médio. A irrigação foi feita com hipoclorito de sódio a 1% a cada troca de instrumento e uma irrigação final com soro fisiológico. As raízes foram divididas em 3 grupos com 18 raízes em cada um, em função dos tratamentos a que foram submetidas as paredes dos canais: Grupo1 - aplicação de EDTA por 5 minutos, agitação com instrumento de memória, irrigação final com soro fisiológico; Grupo 2 - 4 aplicações de laser de Nd:YAG com 15 Hz, 100 mJ e 1,5 Watts com movimentos helicoidais, em cada dente e Grupo 3 - aplicação de EDTA nos moldes do Grupo1 e, após essa etapa, aplicação do laser de Nd:YAG conforme o Grupo 2. Das 18 raízes, 3 foram preparadas para análise ao M.E.V. e as 15 restantes tiveram os canais obturados. A obturação foi feita com guta-percha e cimento AH Plus utilizando a técnica Híbrida de Tagger. Após a obturação foram feitas tomadas radiográficas das raízes para análise da obturação dos canais laterais artificiais. As raízes que foram reservadas para observação ao M.E.V., foram seccionadas longitudinalmente e, então, preparadas para as fotomicrografias onde se procurou evidenciar as embocaduras dos canais laterais e os túbulos dentinários, em cada terço. A análise dos resultados demonstrou não haver diferenças estatisticamente significantes (p > 0,05) entre os procedimentos realizados e nem em relação à obturação dos canais laterais artificiais. As fotomicrografias revelaram que as embocaduras dos canais laterais artificiais, independentemente dos terços analisados, em alguns casos, foram obliteradas com "smear layer" e não por dentina derretida, e que em alguns casos, o laser foi capaz de derreter dentina e selar os túbulos dentinários. / This study aimed at evaluating the influence of EDTA, Nd:YAG laser and the combination of both on the surface of the dentinal walls and for filling of artificial lateral root canals. Fifty-four single-rooted mandibular premolars with one canal were employed. Their crowns were removed and three artificial lateral root canals were prepared, one at each third of one proximal aspect of each root, by means of a reamer with a similar diameter to a K file #15. After preparation of the lateral canals, the main canals were instrumented with K files up to #40 at the apical portion and Gates Glidden burs at the middle and cervical thirds. Irrigation was performed with 1% sodium hypochloride every change of instrument, followed by final irrigation with saline solution. The teeth were divided in three groups with 18 roots each, according to the type of treatment applied to the canal walls: Group 1 - application of EDTA for 5 minutes, agitation with the working length file, and final irrigation with saline solution; Group 2 - four applications of Nd:YAG laser at 15 Hz, 100 mJ and 1.5 Watts with helicoidal movement in each tooth; and Group 3 - application of EDTA as described for group 1, finalizing with application of Nd:YAG laser as described for Group 2. Three roots were prepared for SEM analysis and the remaining 15 roots were obturated. Obturation was carried out with AH plus cement through Tagger's hybrid technique. Radiographs of the roots were then obtained in order to analyze the obturation of the artificial lateral canals. The roots employed for SEM analysis were longitudinally sectioned and prepared for the photomicrographs, in which an attempt was made to demonstrate the openings of the lateral canals and dentinal tubules. No statistically significant differences (p < 0.05) were observed between the performed procedures, neither for the independent analysis of each third regarding obturation of the artificial lateral canals. The photomicrographs revealed that the openings of the artificial lateral canals were obliterated by "smear layer" in some instances, and not by the dissolved dentin. Besides, in some cases the application of laser was unable to dissolve the dentin and seal the dentinal tubules.

O presente trabalho avaliou o efeito do tratamento da superfície radicular por meio da instrumentação com curetas, US e US seguido de curetas, utilizando dentes mineralizados e desmineralizados conjugando a utilização de cítrico e tetraciclina. As superfícies dentais foram analisadas em MEV por um único examinador, sendo utilizados 66 dentes unirradiculares com presença de cálculo indicando doença periodontal. Os dentes foram divididos em 6 grupos experimentais com 10 dentes cada e um grupo controle com 6 dentes sem tratamento. O protocolo de tratamento dos grupos seguiu a seguinte orientação: grupo 1- dentes mineralizados instrumentados com curetas; grupo 2- dentes mineralizados instrumentados com US; grupo 3- dentes mineralizados instrumentados com US, seguindo-se instrumentação com curetas; grupo 4- dentes instrumentados com curetas, desmineralizados e novamente instrumentados com curetas; grupo 5 - dentes instrumentados com US, desmineralizados e novamente instrumentados com US; e, grupo 6- dentes instrumentados com US, desmineralizados e novamente instrumentados com curetas. Foram analisadas a quantidade de cálculo residual (ICR), a rugosidade da superfície radicular (IRS) e perda da substância dentária (IPSD). Os resultados demonstraram diferenças estatísticas significativas quanto ao ICR do grupo 2 em relação aos grupos 3, 4 e 6 e do grupo 5 com os grupos 4 e 6; quanto ao IRS houveram diferenças estatísticas significativas entre o grupo 2 e os grupos 1, 4 e 6 e entre o grupo 5 e os grupos 1 e 6; quanto ao IPSD, observou-se que não houve diferenças estatísticas significativas entre os grupos. O uso de curetas isoladamente ou após US parece melhor se ajustar aos critérios de preparo adequado da raiz, em função dos parâmetros avaliados. / The present work aimed at evaluating the effect of root treatment by instrumentation of not only mineralized teeth with curettes, ultra-sonics (US) and US followed by curettes, but also of teeth intermediately demineralized in combined instrumentations, by using citric acid and tetracycline. The dental surfaces were analysed on SEM by a unique examiner, being utilized 66 uniradicular teeth presenting calculus and thus indicating periodontal disease. The teeth were divided into 6 experimental groups with 10 teeth each and a control group consisting of 6 teeth with no treatment. The treatment protocol for the groups was as follows: group 1- mineralized teeth instrumented with curettes; group 2- mineralized teeth instrumented with US; group 3- mineralized teeth instrumented with US, followed by curette; group 4 - teeth instrumented with curettes, demineralized and again instrumented with curettes; group 5 - teeth instrumented with US, demineralized and again instrumented with US; and, group 6- teeth instrumented with US, demineralized and instrumented with curettes. The amount of residual calculus (RCI), roughness of the radicular surface (SRI) and loss of dental substance (LTSI) were assessed. The results demonstrated statistically significant differences regarding the RCI of group 2 in relation to groups 3, 4 and 6, and that of group 5 with groups 4 and 6; as for the SRI, there were statistically significant differences between group 2 and groups 1, 4 and 6, and between group 5 and groups 1 and 6; no statistically significant differences were observed for the LTSI among groups. The use of curettes, alone or following US, seems more suitable for the criteria of adequate root preparation, as a function of the parameters evaluated.

<div>Wherever we go, we need resources. Finding those resources in unmapped areas is an ever-present challenge. Nature provides many examples of systems that manage to nd the resources they need for growth, despite having little to no information about their environment. Emulating the resource-finding strategies of animals and insects has been, and continues to be, attempted in robotic systems, to varying degrees of success. However, borrowing strategies from plants is much less explored. This dissertation explores an attempt at distilling the resource-hunting methods of plant roots into a collective robotic system.</div><div><br></div><div><div>Utilizing low-power computing and wireless communication, the robots attempt to locate "resources" (radio beacons, in this case) in an unmapped area. They work collectively via extending and branching from each other. The results of this experiment show limited success, with the limitations primarily stemming from the wireless communication. Nonetheless, it is shown that a collective robotic system, emulating plant roots, can feasibly locate resources that display a gradient, with no map of the environment.</div></div>

Vegetation stabilises slopes via both mechanical reinforcement (through root anchorage) and hydrologic reinforcement (through transpiration-induced soil matric suction). However, relatively little is known about the effectiveness of different plant species in stabilising soil slopes via the two reinforcing mechanisms, and so decisions on species selection are seldom made with optimisation of slope reinforcement in mind. In this thesis, a comprehensive testing programme including laboratory, glasshouse and field experiments is designed and implemented, with the aim to quantify and investigate the transpiration-induced hydrologic reinforcement and root biomechanical properties during the early plant establishment of selected woody species, widespread under European temperate climate. Ten species native to Europe (Buxus sempervirens L.; Corylus avellana L.; Crataegus monogyna Jacq.; Cytisus scoparius (L.) Link; Euonymus europaeus L.; Ilex aquifolium L.; Ligustrum vulgare L.; Prunus spinosa L.; Salix viminalis L. and Ulex europaeus L.) were investigated in a glasshouse experiment to understand any relation of transpiration induced hydrologic reinforcement with above- and below-ground plant traits (e.g. specific leaf area; root length density). The ten species showed large differences in terms of water uptake, which translated to significant differences in matric suction and soil strength. Species with the largest water uptake increased soil strength more than ten times that in fallow soil. Specific leaf area, root length density and root:shoot ratio were best correlated with the induced hydrologic reinforcement provided by the ten tested species. These results supplied essential species information for designing the subsequent experiments. Based on the previous findings, three representative yet contrasting species (Corylus avellana, Ilex aquifolim and Ulex europaeus) were selected and planted in 1-m soil columns to investigate the effects of season (i.e. summer vs winter), plant functional type (i.e. deciduous vs evergreen) and soil depth on the magnitude and distribution of transpiration-induced matric suction and the associated soil strength gain. Evergreens could slowly induce matric suction and hence potentially stabilise soil during winter. However, there were very large differences between the tested evergreens (I. aquifolium and U. europaeus). Indeed, only U. europaeus provided matric suction and soil strength gain along the entire depth-profile because of its fast growth (above- and below-ground). A full-scale field experiment was also performed to provide ground-truth data on the extent of variation in hydrologic reinforcement among species, hence validating the glasshouse results obtained in the first two studies. The two-year field experiment yielded a similar ranking to the glasshouse experiments in terms of the species ability to rapidly develop matric suction and soil strength. In particular, the evergreen U. europaeus induced large matric suction (e.g. ≥ 70 kPa at 0.5 m depth) even during the early establishment period. Furthermore, this field research highlighted the greater (compared to other tested species) temporal effectiveness of U. europaeus, which was able to provide matric suction on the slope from early spring to late autumn. The greater ability of U. europaeus in inducing and preserving matric suction can be attributed to its large water uptake, which supports its fast growth, as well as to the notable interception loss provided by its canopy. Therefore, U. europaeus can represent a very suitable species for slope stabilisation under the temperate climate context. Root biomechanical properties, including tensile strength and Young's modulus, were investigated in the laboratory for the same ten species. The results highlighted a large variability in the tensile strength-diameter relations during the early stage establishment of plants, especially in thin roots with diameter ranging from 0.4 to 2.0 mm. The root tensile strength-diameter relationships highlighted three different trends. The common negative power relation between root tensile strength and diameter existed only for two out of the ten tested species (i.e. E. europaeus and U. europaeus). B. sempervirens, I. aquifolium and P. spinosa showed a slight increase in tensile strength with increasing root diameter. C. avellana, C. monogyna and L. vulgare consistently showed an initial increase in root tensile strength with increasing root diameter, reaching peak strength between 1.0 and 2.5 mm diameter. Beyond the peak strength, a reduction in strength was observed with increasing root dimeter. These bimodal trends might be partially explained by the differences in the development stage of root primary and secondary structures. Root moisture content can be one of the factors inducing the observed large variability in root tensile strength. Therefore, the last part of this thesis assessed the effects of root drying on the root biomechanical properties of U. europaeus. Root strength and stiffness showed an abrupt increase when root water content dropped below 0.5 g g-1. The strength increase can be explained by the reduction in root diameter and by changes in root properties induced by the root water potential drop. Moreover, root water loss and root strength gain were diameter-dependent because of the relatively larger evaporative surface per volume of thin roots.