Efeitos individuais e interativos da diversidade de detritos, contexto e variabilidade ambiental sobre a magnitude e estabilidade do processo de decomposição

Studies on the effects of changes in biodiversity and ecosystem functioning have been a central theme in ecology over the past two decades. Several studies have showed that the diversity of plant debris differently affects the decomposition process in aquatic and terrestrial environments, but we know very about the effects of detritus diversity on decomposition under fluctuating environmental conditions. We tested whether and how the environmental contexts, as well as the dynamic of their alternation, influence the effects of detritus diversity on the decomposition process. We performed a field experiment where we manipulate the litter diversity of 8 species of terrestrial plants decomposing (litterbags) in single and in mixture containing the eight species together in three different environmental contexts: the terrestrial environment (T), aquatic (A) and interface (I) - experimental treatment that simulates variation in flooding regime. We measured the rate of decomposition through the loss of mass of the community and each individual detritus in monocultures and mixtures. Species richness and environmental variability had no effects on the magnitude and stability of the decomposition process. However, there were significant diversity effects on the decomposition of an individual alien species, F. benjamina. Environmental context had significant effects on the magnitude and variability of decomposition. Detritus decomposition was faster and more variable on aquatic, interface and terrestrial conditions, respectively. Our results demonstrate that the diversity of plant detritus has minor effects to the decomposition across disparate environmental conditions and suggest that it is necessary to consider the potential of other abiotic factors in affect the magnitude and variability of the decomposition processes

Efeitos de detritos e nutrientes alóctones sobre estrutura e dinâmica trófica de ecossistemas lacustres tropicais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Presença de detritos na região apical de dentes de cães apos o preparo biomecánico com ou sem o emprego de substância auxiliar cremosa.

The subject of this work is to observe if the employment of a cream (ENDO-PTC) during the root canal preparation contributes or not to the condensation of debris in the apical region. Twenty root canals of dogs teeth were divided into two experimental groups: in the first one, the biomechanical preparation was carried out up to the n. 50 Kerr file by using irrigation and aspiration with sodium hypochlorite. In the second experimental group the canal negotiation was done in the same way but using a cream (ENDO-PTC) with sodium hypochlorite as a lubrication substance. A final irrigation and aspiration with sodium hypochlorite was also done in this group. The animal was killed and the pieces prepared for histological analysis. The histological results show us that the employment of a cream during the negotiation of the root canal contributes to a higher condensation of debris in the apical area.

Estudo experimental da remoção, por jato de ar comprimido, de detritos na superfície de corte de rebolo diamantado durante a retificação da alumina refrigerada pela técnica MQL

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso do modelo de simulação 'ABC 6' para avaliação de áreas sujeitas à ocorrência de ondas de cheia e corridas de massa/detritos: estudo de caso na bacia do Ribeirão da Prata (SP)

Pipelines are linear engineering works, designed mostly for transporting oil and its derivatives for long distances, furnishing even the farthermost zones of the country. Due to oil sector needs to ensure for the safety and conservation of its properties, several geotechnical studies are being held at the pipelines field, in order to preserve this important transportation, and also to prevent accidents, which might seriously compromise the environment and the population who lives around it. The OSBRA pipeline, who connects the city of Paulínia to the capital Brasília, is one of these engineering works that deserves to be pointed out. This research, performed at the Ribeirão da Prata Basin, was a pilot study conducted with the main objective of testing the current methodology efficiency, for future applications in the closest watersheds to the OSBRA pipeline. The objective of this research is to analyze flood wave and debris flow processes in a non-fictional watershed, by comparing two different kinds of methods: the first one based on simulation models (software ‘ABC 6’), and the other one by flood wave and debris flow susceptibility mapping. The results from the hydrological modeling were both hydrographs and ietographs that estimated values of outputs and infiltration. To construct the susceptibility maps were necessary three other maps: ground use and occupation maps, divided according to the different protection degrees that were offered to the ground; maps of dam locations in the area and physiographic compartimentation maps, divided according to the local geology. To complete the methodology, the results were collected from both methods for comparison. The obtained product for this methodology was series of data whose different susceptibility degrees to flood wave and debris flow could define the safest route for a pipeline crossing in this watershed...

Elaboração de mapa de susceptibilidade de corridas de massa/detritos e ondas de cheia, aplicado a empreendimentos dutoviários, na bacia hidrográfica do Ribeirão da Prata (SP)

Given the intense expansion of the industries in Brazil and the discovery of hydrocarbons in the pre-salt layer of the Santos and Campos Basin, there is a need to expand the distribution of oil and gas network in the country. The present work aims to present the development of susceptibility map by two distinct methods of two events (debris flows and full wave), applied to the establishment of pipelines on Ribeirão da Prata Basin. The research area covers two municipalities: São João da Boa Vista and Águas da Prata, in total 145 km2. In the paper was used the methodology proposed by Zaine (2011) for the physiographic subdivision method, which uses geological maps, geomorphological maps, digital terrain models and aerial photographs, used to extract the main elements of the physical environment, as rivers, lines, ridges, tops forms and valley forms and historical processes. Thus, the basin was divided into 11 physiographic zones, considering the following elements: thickness of soil, rock type, geomorphology, amplitude, ridges orientation, erosion occurences and mass movements. Were subsequently performed location maps of dams, that had as main purpose to localize major dams in the study area along with their area and perimeter of the reservoir, and land use map that subdivided the area in woody vegetation, permanent culture, temporary culture and urban area. Along with the preparation of the auxiliar maps was conducted a field campaign with three days and approximately 2 points per km2, which aimed to better understand the physical environment and check the main peculiarities of the study area. Criteria have been established for susceptibility maps physiographic subdivision and land use, and a survey of criteria weights used in each map for both processes under study. For the preparation of susceptibility maps were adopted two different methods, which treat the weighted average and the multiplicand. The weighted average method it is...

Efeitos da diversidade funcional de detritos sobre a estrutura de comunidades e o funcionamento de ecossistemas de fitotelmatas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise comparativa "in vitro" da extrusão apical de detritos originados por diferentes técnicas de instrumentação do sistema de canais radiculares

Introdução: A extrusão apical detritos (EAD) consequência indesejável da instrumentação canalar pode ser associada a dor/edema, podendo atrasar a cicatrização periapical. O nosso trabalho teve como objectivo avaliar e quantificar a EAD em canais instrumentados por sistemas de instrumentação rotatória contínua e reciprocante. Materiais e Métodos: 80 dentes monocanalares sem tratamento endodôntico prévio foram aleatoriamente divididos em 4 grupos (n=20): One Shape® Protaper® NEXT, Hyflex® EDM e WaveOne® Gold. Um tubo de Eppendorf (TdE) foi pesado antecipadamente numa balança analítica de precisão e com um dente inserido foi montado num dispositivo modificado, similar ao método descrito por Myers & Montgomery. Os canais foram instrumentados e irrigados com água destilada. Os dentes instrumentados foram removidos dos TdE e estes preenchidos com água destilada até perfazer 1,5ml, incubados a 70ºC durante cinco dias sendo pesados novamente, calculando a diferença entre o peso inicial e final determinando o peso dos detritos. Os dados foram analisados estatisticamente utilizando o IBM SPSS Statistics 22, considerando α=0,05. Efetuaram-se testes Kruskal-Wallis e post-hoc com ajustamento do ρ-value pelo método Dunn-Bonferroni. Resultados: Houve EAD em todas as técnicas de instrumentação. A análise estatística mostrou haver diferenças significativas na EAD entre as técnicas utilizadas (α=0,002). Entre as técnicas WaveOne® Gold e One Shape® (α=0,003), WaveOne® Gold e Protaper® NEXT (α=0,023) e WaveOne® Gold e Hyflex® EDM (α=0,028). Conclusões: A técnica One Shape® apresentou menor EAD e a técnica WaveOne® Gold com movimento reciprocante constitui maior fator de risco tendo apresentado maior EAD. Os resultados deste estudo indicam que os profissionais devem estar cientes para a EAD que pode ocorrer com cada instrumento, o que poderá servir de base para a selecção de um instrumento particular. Implicações clínicas: A escolha do sistema de instrumentação canalar influencia a extrusão de detritos. Fontes de financiamento: Agradecimentos as empresas; Micro-Mega, França, COLTÉNE e Dentsply Maillefer, Suíça.

Avaliação de microplásticos em praias da Baía de Guanabara, Rio de Janeiro, RJ, Brasil

Neste trabalho foram analisados sedimentos marinhos de três praias da Baía de Guanabara (praia de São Bento e praia da Bica, na Ilha do Governador, e praia de São Francisco, em Niterói), Rio de Janeiro, para avaliar a presença de microplásticos (fragmentos plásticos com tamanho ≤ 5 mm) nestes ambientes. Os detritos plásticos visíveis (macroplástico) foram separados dos sedimentos manualmente e pesados. Os detritos plásticos não visíveis foram separados por densidade com solução saturada de cloreto de sódio. Os fragmentos plásticos obtidos com a separação por densidade foram caracterizados por microscopia óptica para avaliar forma e superfície, e foram classificados e quantificados em função de seu tamanho. Os fragmentos microplásticos foram separados e caracterizados por espectrometria de absorção na região do infravermelho por reflexão atenuada (ATR FT IR). Os espectros obtidos foram comparados com espectros padrão de polímeros. As três praias se apresentam contaminadas com lixo macroplástico e com lixo microplástico. Na praia da Bica, foram coletados 173 fragmentos, dos quais 73% são microplásticos. Na praia de São Bento foram 81 fragmentos e na praia de São Francisco foram 73 fragmentos, dos quais 70% e 86%, respectivamente, são microplásticos. Nas três praias foram encontrados fragmentos microplásticos de poliestireno expandido. Nas praias da Bica e de São Bento foram encontrados fragmentos de polietileno; nas praias de São Bento e São Francisco foram encontrados fragmentos microplásticos de polipropileno. O descarte irregular de lixo e atividades industriais e comerciais no entorno da baía podem ser apontados como possíveis fontes contaminantes

Sistema de instrumentação mecanizada reciprocante

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Técnicas e soluções para remoção da Smear Layer

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Impactos de las plantaciones de pino sobre el ciclo de carbono a lo largo de un gradiente de precipitaciones en la Patagonia, Argentina

Los cambios en el uso de la tierra modifican la circulación de carbono (C) entre la atmósfera y los ecosistemas, lo que altera el funcionamiento de estos últimos. Los ecosistemas terrestres juegan un papel central sobre el ciclo de C, pero todavía existen muchas incertidumbres asociadas a los impactos del reemplazo de la vegetación natural sobre los reservorios y flujos de C en condiciones climáticas contrastantes. En esta tesis evaluamos el impacto del reemplazo de la vegetación natural por plantaciones de pino sobre el ciclo de C a lo largo de un gradiente de precipitaciones (250-2200 mm) en la Patagonia. Un gradiente donde la composición de especies y formas de vida de la vegetación varía (de estepas arbustivas graminosas a bosques templados) y ecosistemas pareados donde la vegetación es constante (Pinus ponderosa) permitió explorar los efectos combinados y desacoplados de las precipitaciones y la vegetación sobre la productividad primaria neta aérea (PPNA), la descomposición de broza y el balance de C. A la vez, evaluamos el potencial de secuestro de C de dichas plantaciones. Las plantaciones modificaron el balance de C de los ecosistemas a través de cambios simultáneos en la PPNA y la descomposición, y atenuaron la respuesta de algunas variables biogeoquímicas del suelo a los cambios en las precipitaciones. La PPNA de los ecosistemas naturales y plantaciones aumentó de manera lineal a lo largo del gradiente y la pendiente de la relación PPNA-precipitaciones fue similar entre ecosistemas. La descomposición de broza difirió de manera notable entre ecosistemas y sólo presentó una relación positiva con las precipitaciones en las plantaciones. En los ecosistemas naturales, la combinación de las distintas calidades de broza y los efectos abióticos, como la fotodegradación que disminuye al aumentar la cobertura de la vegetación, generaron tasas de descomposición variables a lo largo del gradiente, y siempre superiores a la de las plantaciones. Las plantaciones incrementaron el contenido de C de la biomasa y detritos entre los 250 a 1350 mm, y lo redujeron con respecto al bosque nativo. El incremento de los detritos estuvo asociado a retrasos en la descomposición, pero estos cambios no se reflejaron en el contenido de carbono orgánico del suelo superficial. En esta tesis identificamos interacciones múltiples entre el clima, la vegetación que se reemplaza y la identidad de la especie introducida, que en conjunto definieron el impacto absoluto y relativo de las plantaciones sobre el balance de C a lo largo del gradiente de precipitaciones. La utilización de plantaciones forestales de la Patagonia como estrategia segura de secuestro de C a largo plazo, presentaría bastante incertidumbre y tendría un papel menor en términos de compensar las emisiones de CO2 a la atmósfera que diversas actividades humanas generan.

Organic contaminants in urban soils: major inputs and potential risks

Urban soil quality may be severely affected by hydrophobic organic contaminants (HOCs), impairing environmental quality and human health. A comprehensive study was conducted in two contrasting Portuguese urban areas (Lisbon and Viseu) in order to assess the levels and potential risks of these contaminants, to identify sources and study their behaviour in soils. The concentrations of HOCs were related to the size of the city, with much higher contamination levels observed in Lisbon urban area. Source apportionment was performed by studying the HOCs profiles, their relationship with potentially toxic elements and general characteristics of soil using multivariate statistical methods. Lisbon seems to be affected by nearby sources (traffic, industry and incineration processes) whereas in Viseu the atmospheric transport may be playing an important role. In a first tier of risk assessment (RA) it was possible to identify polycyclic aromatic hydrocarbons (PAHs) in Lisbon soils as a potential hazard. The levels of PAHs in street dusts were further studied and allowed to clarify that traffic, tire and pavement debris can be an important source of PAHs to urban soils. Street dusts were also identified as being a potential concern regarding human and environmental health, especially if reaching the nearby aquatic bodies. Geostatistical tools were also used and their usefulness in a RA analysis and urban planning was discussed. In order to obtain a more realistic assessment of risks of HOCs to environment and human health it is important to evaluate their available fraction, which is also the most accessible for organisms. Therefore, a review of the processes involved on the availability of PAHs was performed and the outputs produced by the different chemical methods were evaluated. The suitability of chemical methods to predict bioavailability of PAHs in dissimilar naturally contaminated soils has not been demonstrated, being especially difficult for high molecular weight compounds. No clear relationship between chemical and biological availability was found in this work. Yet, in spite of the very high total concentrations found in some Lisbon soils, both the water soluble fraction and the body residues resulting from bioaccumulation assays were generally very low, which may be due to aging phenomena. It was observed that the percentage of soluble fraction of PAHs in soils was found to be different among compounds and mostly regulated by soil properties. Regarding bioaccumulation assays, although no significant relationship was found between soil properties and bioavailability, it was verified that biota-to-soil bioaccumulation factors were sample dependent rather than compound dependent. In conclusion, once the compounds of potential concern are targeted, then performing a chemical screening as a first tier can be a simple and effective approach to start a RA. However, reliable data is still required to improve the existing models for risk characterization.

O conteúdo orgânico do sedimento influencia na distribuição intraespecífica de caranguejos-chama-maré

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)