985 resultados para Synonymous co-variation


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Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

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Studies have shown the cariostatic effect of Er,Cr:YSGG (2.78 mm) laser irradiation on human enamel and have suggested its use on caries prevention. However there are still no reports on the intrapulpal temperature increase during enamel irradiation using parameters for caries prevention. The aim of this in vitro study was to evaluate the temperature variation in the pulp chamber during human enamel irradiation with Er,Cr:YSGG laser at different energy densities. Fifteen enamel blocks obtained from third molars (3 x 3 x 3 mm) were randomly assigned to 3 groups (n=5): G1 - Er,Cr:YSGG laser 0.25 W, 20 Hz, 2.84 J/cm², G2 - Er,Cr:YSGG laser 0.50 W, 20 Hz, 5.68 J/cm², G3 - Er,Cr:YSGG laser 0.75 W, 20 Hz, 8.52 J/cm². During enamel irradiation, two thermocouples were fixed in the inner surface of the specimens and a thermal conducting paste was used. One-way ANOVA did not show statistically significant difference among the experimental groups (a=0.05). There was intrapulpal temperature variation <0.1ºC for all irradiation parameters. In conclusion, under the tested conditions, the use of Er,Cr:YSGG laser with parameters set for caries prevention lead to an acceptable temperature increase in the pulp chamber.

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Echinolaena inflexa (Poir.) Chase is an abundant C3 grass species with high biomass production in the Brazilian savanna (cerrado); Melinis minutiflora Beauv. is an African C4 forage grass widespread in cerrado and probably displacing some native herbaceous species. In the present work, we analysed seasonally the content and composition of soluble carbohydrates, the starch amounts and the above-ground biomass (phytomass) of E. inflexa and M. minutiflora plants harvested in two transects at 5 and 130 m from the border in a restrict area of cerrado at the Biological Reserve and Experimental Station of Mogi-Guaçu (SP, Brazil). Results showed that water soluble carbohydrates and starch amounts from the shoots of both species varied according to the time of the year, whilst in the underground organs, variations were observed mainly in relation to the transects. Marked differences in the pattern of the above-ground biomass production between these two grasses relative to their location in the Reserve were also observed, with two peaks of the invasive species (July and January) at the Reserve border. The differences in carbohydrate accumulation, partitioning and composition of individual sugars concerning time of the year and location in the Reserve were more related to the annual growth cycle of both grasses and possibly to specific physiological responses of M. minutiflora to disturbed environments in the Reserve border.

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Phytoplankton may function as a "sensor" of changes in aquatic environment and responds rapidly to such changes. In freshwaters, coexistence of species that have similar ecological requirements and show the same environmental requirements frequently occurs; such species groups are named functional groups. The use of phytoplankton functional groups to evaluate these changes has proven to be very useful and effective. Thus, the aim of this study was to evaluate the occurrence of functional groups of phytoplankton in two reservoirs (Billings and Guarapiranga) that supply water to millions of people in São Paulo city Metropolitan Area, southeastern Brazil. Surface water samples were collected monthly and physical, chemical and biological (quantitative and qualitative analyses of the phytoplankton) were performed. The highest biovolume (mm³.L-1) of the descriptor species and functional groups were represented respectively by Anabaena circinalis Rabenh. (H1), Microcystis aeruginosa (Kützing) Kützing (L M/M) and Mougeotia sp. (T) in the Guarapiranga reservoir and Cylindrospermopsis raciborskii (Wolosz.) Seen. and Subba Raju (S N), Microcystis aeruginosa and M. panniformis Komárek et al. (L M/M), Planktothrix agardhii (Gom.) Anagn. and Komárek and P. cf. clathrata (Skuja) Anagn. and Komárek (S1) in the Billings reservoir. The environmental factors that most influenced the phytoplankton dynamics were water temperature, euphotic zone, turbidity, conductivity, pH, dissolved oxygen, nitrate and total phosphorous.

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Troglobitic (exclusively subterranean) organisms usually present, among their apomorphies related to the subterranean life (troglomorphisms), the regression of eyes and melanic pigmentation. The degree of regression varies among species, from a slight reduction to the complete loss of eyes and dark pigmentation, without a taxonomic correlation. While mechanisms of eye reduction have been intensively investigated in some troglobites such as the Mexican blind tetra characins, genus Astyanax, and the European salamander, Proteus anguinus, few studies have focused on pigmentation. The Brazilian subterranean ichthyofauna distinguishes not only by the species richness (23 troglobitic fishes so far known) but also by the variation in the degree of reduction of eyes and pigmentation. This study focused on Brazilian fishes completely devoid of melanic pigmentation: the characiform Stygichthys typhlops (Characidae) and the siluriforms Ancistrus formoso (Loricariidae), Rhamdiopsis sp.1 (Heptapteridae; from caves in the Chapada Diamantina, Bahia) and Rhamdiopsis sp. 2 (cave in Campo Formoso, Bahia). In order to investigate if such depigmentation is the result of blockage in some step in the melanogenesis, in vitro tests of administration of L-DOPA were done, using caudal-fin fragments extracted from living fish. Except for Rhamdiopsis sp. 2, all the studied species were DOPA(+), i.e., melanin was synthesized after L-DOPA administration. This indicates these fish do have melanophores but they are unable to convert L-tyrosine to L-DOPA. On the other hand, Rhamdiopsis sp. 2, like the albino specimens of Trichomycterus itacarambiensis previously studied (which correspond to one third of the population), are DOPA(-), either because the block of melanin synthesis occurs downstream in melanogenesis, which is probably the case with T. itacarambiensis (monogenic system in view of the phenotypic discontinuity), or because the so-called albinos do no possess melanophores. The physiological loss in the ability to synthesize melanin, apparently caused by different genetic processes in DOPA(+) and in DOPA(-) fishes, may co-exist in subterranean populations with a decrease in the density of melanophores, as observed in the pigmented two thirds of T. itacarambiensis population, a morphological reduction apparently controlled by polygenic systems producing a continuous phenotypic variation.

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Hydroids are broadly reported in epiphytic associations from different localities showing marked seasonal cycles. Studies have shown that the factors behind these seasonal differences in hydroid richness and abundance may vary significantly according to the area of study. Seasonal differences in epiphytic hydroid cover and richness were evaluated in a Sargassum cymosum C. Agardh bed from Lázaro beach, at Ubatuba, Brazil. Significant seasonal differences were found in total hydroid cover, but not in species richness. Hydroid cover increased from March (early fall) to February (summer). Most of this pattern was caused by two of the most abundant species: Aglaophenia latecarinata Allman, 1877 and Orthopyxis sargassicola (Nutting, 1915). Hydroid richness seems to be related to S. cymosum size but not directly to its biomass. The seasonal differences in hydroid richness and algal cover are shown to be similar to other works in the study region and in the Mediterranean. Seasonal recruitment of hydroid species larvae may be responsible for their seasonal differences in algal cover, although other factors such as grazing activity of gammarid amphipods on S. cymosum must be taken into account.

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Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 ºC, these revealed insulator at the lowest sintering temperature, changing to semiconducting and PTCR-type materials only when the sintering temperature was further increased. Observations from X-ray diffraction help correlating this effect with phase development in this formulated (Ba,Ca,Er)TiO3 system, considering the formation of initially two separated major (Ba,Ca)TiO3- and minor (Ca,Er)TiO3-based compounds, as a consequence of cation size-induced stress energy effects. Thus, appearance and enhancement here of the semiconducting and PTCR responses towards higher sintering temperatures particularly involve the incorporation of Er3+ into the major phase, rendering finally possible the generation and "percolative-like" migration of electrons throughout the whole material.

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The aim of this study was to determine how abiotic factors drive the phytoplankton community in a water supply reservoir within short sampling intervals. Samples were collected at the subsurface (0.1 m) and bottom of limnetic (8 m) and littoral (2 m) zones in both the dry and rainy seasons. The following abiotic variables were analyzed: water temperature, dissolved oxygen, electrical conductivity, total dissolved solids, turbidity, pH, total nitrogen, nitrite, nitrate, total phosphorus, total dissolved phosphorus and orthophosphate. Phytoplankton biomass was determined from biovolume values. The role abiotic variables play in the dynamics of phytoplankton species was determined by means of Canonical Correspondence Analysis. Algae biomass ranged from 1.17×10(4) to 9.21×10(4) µg.L-1; cyanobacteria had biomass values ranging from 1.07×10(4) to 8.21×10(4) µg.L-1. High availability of phosphorous, nitrogen limitation, alkaline pH and thermal stability all favored cyanobacteria blooms, particularly during the dry season. Temperature, pH, total phosphorous and turbidity were key factors in characterizing the phytoplankton community between sampling times and stations. Of the species studied, Cylindrospermopsis raciborskii populations were dominant in the phytoplankton in both the dry and rainy seasons. We conclude that the phytoplankton was strongly influenced by abiotic variables, particularly in relation to seasonal distribution patterns.

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In this work, the perovskite-type oxides LaNiO3, LaMnO3, La0,7Sr0,3NiO3 and La0,7Sr0,3MnO3 were prepared by co-precipitation and tested in the NO reduction with CO at 400 and 500 ºC for 10 h. The catalysts were characterized by X-ray diffraction, temperature programmed reduction with hydrogen, nitrogen adsorption and chemical analysis. The nonstoichiometric oxygen was quantified by temperature programmed reduction, and the catalytic tests showed that the La0,7Sr0,3MnO3 catalyst presented the higher performance for the reduction reaction of NO with CO. The partial substitution of lanthanum by strontium increased the NO conversion and the N2 yield.

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It is investigated in the present contribution the oscillatory co-electrodeposition of CuSn on a polycrystalline gold surface in the presence of Triton X-100 surfactant and citric acid as additive, in acidic media. The experiments were conducted under potentiostatic control and the system dynamics characterized in terms of the morphology and stability of the current oscillations. Besides modulations in the frequency and amplitude of the current oscillations, several patterned states were observed, including relaxation-like and mixed mode oscillations. The oscillations were found to be very robust and some time series presented regular motions up to about two hours.

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The results obtained in the August and December 2003, August 2004 and January 2005 oceanographic campaigns in the northern region of the Todos os Santos Bay (lat. 12º44.5'S; long. 038º35.00'W) between the Madre de Deus and Maré islands are analyzed. Instruments of continuous and discrete samplings were used to measure hydrographic properties currents and tides. The water mass of the northern region of the bay is forced by semidiurnal and mesotides of form number 0.08 and the lunar component M2 height was estimated at 91cm. The time series of the surface currents indicated movements in the N/S direction, forced by the tide with maximum magnitudes of 0.73 m.s-1 on the December 2003 campaign. However, in August 2004 the currents were dominated by the wind stress forcing, with a maximum speed of 1.85 m.s-1 and SE direction. Near the bottom, the influence of the tide is not as evident, with a decrease in intensity due to internal and bottom friction, with a maximum velocity of 0.17 m.s-1. The thermal and haline structures were weakly horizontally, as well as vertically stratified, with extreme values varying in the intervals 23ºC (August, 2004) to 28ºC (December, 2003) and 31.0 psu (August, 2003) to 36.0 psu (December, 2003), respectively. Some conclusions may be drawn from these results: i) The signs of the dilution of the fresh water discharges of the Caípe, Mataripe and São Paulo rivers in the region under the influence of the RLAM were observed only during the winter periods, but in the summer the region was flooded by waters of oceanic origin and the salinities above 36.0 indicated TW mass intrusion; ii) The N-S circulation near the RLAM is strongly dominated by the tide, and the importance of the M2 component was unequivocal, however, the E-W component presented some tidal modulation away from abrupt bottom topographical changes, and iii) The residual series, calculated as the difference between the original and modeled, is about ¼ of the original and confirmed its semidiurnal character.

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OBJETIVO: Identificar áreas de vulnerabilidade para os casos novos de co-infecção HIV/tuberculose (TB). MÉTODOS: Estudo descritivo ecológico realizado por meio do georreferenciamento dos casos novos de HIV/TB notificados em Ribeirão Preto, SP, em 2006. Os dados foram obtidos do sistema de informação estadual paulista de notificação de TB. Os casos novos de co-infecção HIV/TB foram analisados conforme características sociodemográficas e clínicas e, posteriormente, georreferenciados na base cartográfica do município segundo endereço residencial. Os setores do município foram categorizados em três níveis socioeconômicos: inferior, intermediário e superior, com base na análise de componentes principais das variáveis do censo demográfico de 2000 (renda, instrução e percentagem de domicílios com cinco ou mais moradores). Foi calculada a incidência da co-infecção HIV/TB para cada nível socioeconômico. RESULTADOS: A co-infecção HIV/TB acometeu mais adultos do sexo masculino em idade economicamente ativa e a forma pulmonar da TB foi a mais comum. A distribuição espacial mostrou que as incidências nas áreas com níveis socioeconômicos intermediários e inferiores (8,3 e 11,5 casos por 100 mil habitantes, respectivamente) foram superiores àquela (4,8 casos por 100 mil habitantes) de nível socioeconômico superior. CONCLUSÕES: A taxa de incidência de co-infecção HIV/TB analisada por níveis socioeconômicos mostrou padraÞo espacial de distribuiçaÞo não homogêneo e apresentou valores mais altos em áreas de maior vulnerabilidade social. O estudo diagnosticou aìreas geograìficas prioritaìrias para o controle da co-infecção e a tecnologia do sistema de informação geográfica pode ser empregada no planejamento das ações em saúde pelos gestores municipais.

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The aim of the current study was to describe the sources of variation of energy and nutrient intake and to calculate the number of repetitions of diet measurements to estimate usual intake in adolescents from São Paulo, Brazil. Data was collected using 24-hour dietary recalls (24hR) in 273 adolescents between 2007 and 2008. Individuals completed a repeat 24hR around two months later. The sources of variation were estimated using the random effect model. Variance ratios (within-person to between-person variance ratio) and the number of repetitions of 24hR to estimate usual intake were calculated. The principal source of variation was due to within-person variance. The contribution of day of week and month of year was less than 8%. Variations ranged from 1.15 for calcium to 7.31 for vitamin E. The number of 24hR repeats required to estimate usual intake varied according to nutrient and gender, numbering 15 for males and 8 for females.

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O objetivo do trabalho foi reportar o planejamento cirúrgico, a técnica operatória, a instrumentação e os resultados da substituição completa do terço médio distal do fêmur, do platô tibial e da articulação do joelho por prótese em um cão acometido por osteossarcoma no fêmur esquerdo. A prótese foi confeccionada em aço, apresentando três componentes articulados, mantendo o movimento semelhante à articulação do joelho. As porções femorais e tibiais da prótese foram cimentadas aos respectivos ossos, após ostectomia do fêmur e do platô tibial. O animal foi submetido a seis sessões de quimioterapia, com doxorrubicina e carboplatina, intercaladas mensalmente, objetivando inibir o crescimento de possíveis metástases pulmonares. Durante os seis primeiros dias, o animal apresentou neuropraxia e impotência funcional do membro. Aos 10 dias, o cão iniciou leve apoio e aos 30 dias já utilizava o membro pélvico de forma mais efetiva, porém, o ângulo de extensão da articulação foi reduzido de 150° a 100° devido à contratura muscular e à fibrose na região da fossa poplítea. Após um ano de observação, não houve melhora do ângulo de extensão do joelho, porém, o animal fazia uso do membro com claudicação. Aos 425 dias de pós-operatório, o animal veio a óbito por insuficiência renal. Nesse tempo não ocorreram metástases pulmonares ou locais visíveis radiograficamente, mas o proprietário não permitiu a realização da necropsia do paciente, sendo impossível confirmar outros dados que pudessem esclarecer melhor a causa morte. Conclui-se que a substituição total do joelho de cão é uma cirurgia factível, que permite a preservação e a utilização do membro após ressecção da neoplasia, embora outras pesquisas devam ser conduzidas para obtenção de melhores resultados pós-cirúrgicos.

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A Meningoencefalite Necrotizante (MEN) é uma encefalopatia causada por uma disfunção inflamatória de característica necrotizante. O objetivo deste relato é descrever os aspectos clínicos e anatomopatológicos da Meningoencefalite Necrotizante (MEN) em um cão Maltês. A doença tem um caráter necrótico único e está relacionada intimamente à Encefalite do Cão Pug (ECP) devido a suas semelhanças, bem como à Leucoencefalite Necrotizante (LEN). Embora o primeiro relato de caso de ECP tenha mais de 15 anos e o primeiro relato de caso de MEN em Maltês tenha 11 anos, há muito a ser revelado sobre a etiologia e os mecanismos imunopatológicos da doença. Neste trabalho, relata-se o caso de um cão Maltês com sinais que foram compatíveis com a MEN. Foram detectadas nas imagens macroscópicas, cavitação cerebral, e na microscopia, perda de células do parênquima em certas regiões do córtex cerebral. A partir dessas descobertas descreve-se o primeiro caso de MEN em cão Maltês no Brasil.