434 research outputs found
SPATIAL OUTLIERS DETECTION ALGORITHM (SODA) APPLIED TO MULTIBEAM BATHYMETRIC DATA PROCESSING
The amount of data produced in an echo sounder has grown exponentially with scanning systems such as multibeam echo sounders and interferometric sonars, providing a considerable improvement in the submerged relief representation, especially to detect hazard objects to the navigator. However, the available processing algorithms did not follow this evolution; manual processing is usually necessary or at least constant intervention by an analyst, making this task arduous with a high subjectivity degree. In addition, statistical inconsistencies are common in most of the algorithms and filters available. Thus, SODA (Spatial Outliers Detection Algorithm) was recently presented, which is a methodology directed at first for echo sounder data treatment. The authors evaluated the algorithm efficiency using simulated data. Therefore, this article aimed to evaluate the SODA efficiency for real data treatment, with a multibeam echo sounder. A number of interesting results was obtained, reaffirming the methodology strength, regarding the search for spikes in echo sounder data
POINT TO POINT: AN ALTERNATIVE METHOD FOR EXTRACTING “HOMOLOGOUS POINTS” IN BATHYMETRIC DATA COLLECTED WITH A MULTIBEAM SYSTEM
Due to waterway transport efficiency, mainly for commercial trades, the use of sea/river routes has grown recently. So, the importance of producing high quality nautical charts stands out. A nautical chart is the hydrographic survey final product and its accuracy depends on data quality collected, primarily of the vertical quality (depth). In this sense, despite the theoretical and practical difficulty in obtaining homologous points in hydrographic surveys, even when performing check lines, bathymetric data must always be delivered with a statistically proven confidence level. Thus, this study has two main objectives: i) to propose a method, called Point to Point (P2P), for obtaining “homologous points” for hydrographic surveys carried out with multibeam systems, without resorting to mathematical and/or statistical interpolations, called Point to Point (P2P); ii) to quantify the magnitude of the difference between the statistical evaluation using check lines (CL) and by overlapping successive sounding lines (SL), applying the P2P method. The results showed that P2P is easy to application, provide low computation effort, is robust and consistent. Besides that, was possible to applied successive regular lines to get a validation of the hydrographic survey
Estratégia e desempenho de plataformas audiovisuais de streaming
Purpose: This work aims to analyze and classify the competitive strategies of 37 streaming platforms and identify which strategic groups perform better globally.
Design/methodology/approach: This study is based on the structure-conduct-performance paradigm and uses Porter's typology to reach its goal. It classified the 37 platforms into their respective strategic groups based on eight strategic variables using k-means cluster analysis. Then, group performances were compared using ANOVA to test the mean differences of two performance variables.
Originality/relevance: The audiovisual industry is experiencing a radical change in content consumption, distribution, and production. Streaming technology, which delivers content over the internet without downloads, increased flexibility and sparked a wave of adoption of audiovisual streaming platforms that destabilized other sectors, such as home video. Consequently, this phenomenon left a gap in studies about the strategy and performance of the industry, which this paper intends to fill.
Main findings: As a result, 14% of the platforms studied were allocated to the Differentiation strategic group, 30% to Cost Leadership, 19% to Differentiation Focus, 8% to Cost Focus, and 30% were considered Stuck-In-The-Middle. We identified that the strategic groups present significant differences in performance, validating the applicability of Porter's typology.
Theoretical contributions: The study found that broad-spectrum strategies such as Cost Leadership and Differentiation promote better performance than focus strategies at this industry stage. Surprisingly, Stuck-In-The-Middle companies also perform well, similar to companies with broad-spectrum strategies.Propósito: Este trabajo tiene como objetivo analizar y clasificar las estrategias competitivas de 37 plataformas de streaming e identificar qué grupos estratégicos se desempeñan mejor a nivel global.
Diseño/metodología/enfoque: Este estudio se basa en el paradigma estructura-conducta-desempeño y utiliza la tipología de Porter para lograr su objetivo. Clasificó las 37 plataformas en sus respectivos grupos estratégicos en función de ocho variables estratégicas utilizando un análisis de conglomerados de k-medias. Luego, se compararon los desempeños grupales utilizando ANOVA para probar las diferencias medias de dos variables de desempeño.
Originalidad/relevancia: La industria audiovisual está experimentando un cambio radical en el consumo, distribución y producción de contenidos. La tecnología de streaming, que ofrece contenidos a través de Internet sin descargas, aumentó la flexibilidad y provocó una ola de adopción de plataformas de streaming audiovisual que desestabilizó otros sectores, como el del vídeo doméstico. En consecuencia, este fenómeno dejó un vacío en los estudios sobre la estrategia y el desempeño de la industria, que este artículo pretende llenar.
Principales hallazgos: Como resultado, el 14% de las plataformas estudiadas se asignaron al grupo estratégico de Diferenciación, el 30% al Liderazgo en Costos, el 19% al Enfoque en Diferenciación, el 8% al Enfoque en Costos y el 30% se consideraron ‘Stuck-in-the-middle’. Identificamos que los grupos estratégicos presentan diferencias significativas en su desempeño, validando la aplicabilidad de la tipología de Porter.
Contribuciones teóricas: El estudio encontró que las estrategias de amplio espectro como el liderazgo en costos y la diferenciación promueven un mejor desempeño que las estrategias de enfoque en esta etapa de la industria. Sorprendentemente, las empresas ‘Stuck-in-the-middle’ también obtienen buenos resultados, al igual que las empresas con estrategias de amplio espectro.Objetivo: Este artigo analisa e classifica as estratégias de 37 plataformas de streaming, identificando quais grupos estratégicos mostram melhor desempenho global.
Concepção/metodologia/abordagem: Este estudo se baseia no paradigma estrutura-conduta-desempenho, e utiliza a tipologia de Porter para alcançar seu objetivo. Classificamos as 37 plataformas em seus respectivos grupos estratégicos, com base em oito variáveis estratégicas, utilizando a análise de cluster K-means. Em seguida, os desempenhos dos grupos foram comparados utilizando ANOVA, para testar as diferenças de médias de duas variáveis de desempenho.
Originalidade/relevância: A indústria audiovisual está passando por uma mudança radical no consumo, distribuição e produção de conteúdo. A tecnologia de streaming, que fornece conteúdo pela Internet sem a necessidade de download, aumentou a flexibilidade e provocou uma onda de adoção de várias plataformas de streaming audiovisual, desestabilizando outros setores, como o de home video. Consequentemente, esse fenômeno abriu uma lacuna nos estudos sobre estratégia e desempenho do setor, que este artigo visa preencher.
Principais resultados: 14% das plataformas estudadas enquadram-se no grupo estratégico de Diferenciação, 30% em Liderança em Custo, 19% em Foco em Diferenciação, 8% em Foco em Custo, e 30% foram consideradas Stuck-in-the-Middle. Os grupos estratégicos apresentaram diferenças significativas de desempenho, validando, assim, a aplicação da tipologia de Porter.
Contribuição Teórica: O estudo mostra que estratégias de amplo espectro, como Liderança em Custo e Diferenciação, obtiveram melhor desempenho do que estratégias de foco neste setor. Surpreendentemente, as empresas Stuck-in-the-Middle também tiveram bom desempenho, semelhante ao das empresas com estratégias de amplo escopo
Estresse oxidativo sistêmico e folicular em mulheres inférteis com endometriose submetidas à injeção intracitoplasmática de espermatozoide
ResumoObjetivoComparar oito marcadores de estresse oxidativo (EO) no soro e no fluido folicular (FF) de mulheres inférteis com e sem endometriose (E) submetidas à estimulação ovariana controlada (EOC) para injeção intracitoplasmática de espermatozoide (ICSI).Material e métodosForam coletadas 87 amostras de soro (43 com E e 44 sem E – com fator tubário e/ou masculino) e 61 amostras de FF (29 com E e 32 sem E) no dia da captação oocitária. Hidroperóxidos totais (FOX1), malondialdeído (MDA), produtos avançados de oxidação proteica (AOPP), glutationa (GSH), superóxido dismutase (SOD) e capacidade antioxidante total (CAT) foram determinados por espectrofotometria; vitamina E (Vit E) por cromatografia líquida de alta eficiência; e 8‐hidroxi‐2’‐deoxiguanosina (8OHdG) por ELISA.ResultadosForam observadas maiores concentrações séricas de GSH (220,32±43,2 nmol/g pt) e SOD (677,9±282,21 U/mL), menores concentrações séricas da CAT (0,34±0,17 mEq Trolox/L) e maiores concentrações foliculares de 8OHdG (23,19±6,8ng/mL) e Vit E (13,0±5,33μmol/L) em mulheres inférteis com E comparadas às sem E (193,92±43,25 nmol/g pt, 563,04±169,82 U/mL, 0,46±0,15 mEq Trolox/L, 17,22±5,6ng/mL e 8,71±2,51μmol/L, respectivamente).ConclusõesFoi evidenciado EO sistêmico e folicular em pacientes inférteis com E submetidas à EOC para ICSI. Sugerimos que o EO possa estar envolvido na etiopatogênese da infertilidade relacionada à doençaAbstractObjectivesThe aim of the study was to compare eight oxidative stress (OS) markers in serum and follicular fluid (FF) of infertile women with and without endometriosis (E) undergoing controlled ovarian stimulation (COS) for intracytoplasmic sperm injection (ICSI).Material and methodsEight‐seven serum samples (43 with E and 44 without E ‐ with male or tubal factor) and 61 FF samples (29 with E and 32 without E) were collected in the day of oocyte retrieval. Total hydroperoxides (FOX1), malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH), superoxide dismutase (SOD) and the total antioxidant capacity (TAC) were determined by spectrophotometry, vitamin E (Vit E) by high performance liquid chromatography, and 8‐hydroxy‐2’–deoxyguanosine (8OHdG) by ELISA.ResultsWe observed higher serum concentrations of GSH (220.32±43.2 nmol/g pt) and SOD (677.9±282.21 U/mL), lower serum concentrations of TAC (0.34±0.17 mEq Trolox/L), and higher follicular concentrations of 8OHdG (23.19±6.8ng/mL) and Vit E (13.0±5.33μmol/L) in infertile women with E compared to those without E (193.92±43.25 nmol/g pt, 563.04±169.82 U/mL, 0.46±0.15 mEq Trolox/L, 17.22±5.6ng/mL and 8.71±2.51μmol/L, respectively).ConclusionsWe evidenced the occurrence of systemic and follicular OS in infertile patients with E undergoing COS for ICSI. We suggest that the OS may be involved in the etiopathogenesis of infertility‐related diseas
Characteristics of pollen collected by five species of Meliponid Bees of Central Amazonia
The pollen grains collected by Melipona seminigra merrillae, Melipona compressipes manaosensis, Melipona seminigra seminigra, Frieseomelitta sp. and Scaptotrigona sp. were obtained directly from the corbiculae of the worker bees during one year. Identification of the pollen grains showed that Scaptotrigona sp. was the most generalist bee, followed by Frieseomelitta sp., which together collected more pollen taxa than the three species of Melipona. Pollen from three plant species: - Miconia myrianthera, Myrcia amazonica e Tapirira guianensis -were collected by this five bee species. Regarding pollen morphology, no significant correlations were found that could indicate a preference for certain pollen grain forms, external structures or sizes of grains. All five meliponids collected pollen of several forms and sizes. It is indicative that the bees collected pollen in accordance to protoplasmic nutrients. Biochemical analyses of some pollen types carried on the corbiculae of the bees showed a high concentration of total soluble sugars, reductive sugars and starch.Durante um ano, o pólen transportado por Melipona compressipes manaosensis, Melipona seminigra merrillae, Melipona seminigra seminigra, Frieseomelitta sp. e Scaptotrigona sp. foi coletado diretamente das corbículas das operárias. Feita a identificação dos grãos de pólen constatou-se que a abelha mais generalista foi Scaptotrigona sp., seguida de Frieseomelitta sp., as quais juntas coletaram mais tipos polínicos que as três espécies de meliponas. Duas espécies de plantasMiconia myrianthera e Myrcia amazonica, tiveram seu pólen coletado pelas cinco espécies de meliponíneos durante o ano todo. Quanto à morfologia do pólen, não houve correlação significativa que comprovasse que as abelhas coletassem o pólen de acordo com a forma, ornamentação e o tamanho dos grãos. As cinco espécies de meliponíneos coletaram pólen de diversas formas e tamanhos. Tudo indica que as abelhas coletam o pólen de acordo com os nutrientes contidos no seu protoplasma. Análises bioquímicas de alguns tipos polínicos encontrados nas corbículas das abelhas apresentaram alto teor de açúcares solúveis totais, açúcares redutores e amido
Reactivity of paraquat with sodium salicylate: formation of stable complexes
Sodium salicylate (NaSAL) has been shown to be a promising antidote for the treatment of paraquat (PQ) poisonings. The modulation of the pro-oxidant and pro-inflammatory pathways, as well as the antithrombogenic
properties of NaSAL are probably essential features for the healing effects provided by this drug. Nevertheless, a possible direct chemical reactivity between PQ and NaSAL is also a putative pathway to be considered, this hypothesis being the ground of the present study. In accordance, it is shown, for the first time that PQ and NaSAL react immediately in aqueous medium and within 2–3 min in the solid state. Photographs and scanning electron photomicrographs indicated that a new chemical entity is formed when both compounds are mixed. This assumption was corroborated by the evaluation of the melting point, and through several analytical techniques, namely ultraviolet/visible spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography/mass spectrometry/mass spectrometry (GC/MS/MS), liquid chromatography/electrospray ionization/mass spectrometry/mass spectrometry (LC/ESI/MS/MS)
and infrared spectroscopy, which revealed that stable charge-transfer complexes are formed when PQ is mixed with NaSAL. LC/ESI/MS/MS allowed obtaining the stoichiometry of the charge-transfer complexes. In order to increase resolution, single value decomposition, acting as a filter, showed that the chargetransfer complexes withm/z 483, 643 and 803 correspond to the pseudo-molecular ions, respectively 1:2, 1:3 and 1:4 (PQ:NaSAL). In conclusion, these results provided a new and important mechanism of action of NaSAL against the toxicity mediated by PQ
Concepts in Management of Advanced Craniomaxillofacial Injuries
The authors present a sequencing assessment of patients who were victims of traumatic deformities of the craniomaxillofacial complex. To that end, the authors highlight the eight steps worthy of particular attention, namely (1) clinical history and photographic documentation; (2) clinical assessment; (3) assessment through image and diagnostic exams; (4) planning of the treatment; (5) bases for the three-dimensional reconstruction of the face; (6) reconstruction sequence of multiple facial fractures; (7) support measures; and (8) complications. The proposed assessment sequence allows the oral and maxillofacial surgeon or craniomaxillofacial surgeon to assess the degree of impairment of traumatic deformity, which contributes in a significant way to the decision-making process of the treatment
The cytotoxic effect of TiF4 and NaF on fibroblasts is influenced by the experimental model, fluoride concentration and exposure time.
OBJECTIVE: Titanium tetrafluoride (TiF4) has shown promising effect in preventing tooth lesions. Therefore, we compared the cytotoxicity of TiF4 with sodium fluoride (NaF) (already applied in Dentistry) considering different fluoride concentrations, pH values and experimental models. MATERIALS AND METHODS: Step 1) NIH/3T3 fibroblasts were exposed to mediums containing NaF or TiF4 (from 0.15 to 2.45% F), both at native and adjusted pH, for 6 h. Step 2) NIH/3T3 were exposed to NaF or TiF4 varnishes with 0.95, 1.95 or 2.45% F (native pH), for 6, 12 or 24 h. We applied MTT (1st and 2nd steps) and Hoescht/PI stain (2nd step) assays. Step 3) NIH/3T3 were exposed to NaF or TiF4 varnish (2.45% F), at native pH, for 6 or 12 h. The cell stiffness was measured by atomic force microscopy (AFM). RESULTS: Step 1) All cells exposed to NaF or TiF4 mediums died, regardless of the F concentration and pH. Step 2) Both varnishes, at 1.90 and 2.45% F, reduced cell viability by similar extents (33-86% at 6 h, 35-93% at 12 h, and 87-98% at 24 h) compared with control, regardless of the type of fluoride. Varnishes with 0.95% F did not differ from control. Step 3) TiF4 and NaF reduced cell stiffness to a similar extent, but only TiF4 differed from control at 6 h. CONCLUSIONS: Based on the results of the 3 experimental steps, we conclude that TiF4 and NaF have similar cytotoxicity. The cytotoxicity was dependent on F concentration and exposure time. This result gives support for testing the effect of TiF4 varnish in vivo
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