Positive leader characteristics from high-speed video observations

Based on analyses of high-speed video recordings of cloud-to-ground lightning in Brazil and the USA, the characteristics of positive cloud-to-ground (+CG) leaders are presented. The high frame rates permitted the average, 2-dimensional speeds of development along the paths of the channels to be resolved with good accuracy. The values range from 0.3 to 6.0 x 10(5) ms(-1) with a mean of 2.7 x 10(5) ms(-1). Contrary to what is usually assumed, downward +CG leader speeds are similar to downward -CG leader speeds. Our observations also show that the speeds tend to increase by a factor of 1.1 to 6.5 as they approach the ground. The presence of short duration, recoil leaders (RLs) during the development of positive leaders reveal a highly branched structure that is not usually recorded when using conventional photographic and video cameras. The existence of the RLs may help to explain observations of UHF-VHF radiation during the development of +CG flashes.

High-speed video observations of positive ground flashes produced by intracloud lightning

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ovariectomy by laparotomy, a video-assisted approach or a complete laparoscopic technique in Santa Ines sheep

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

Hybrid visual-driven decision support system in video monitor manufacturing

An intelligent system that emulates human decision behaviour based on visual data acquisition is proposed. The approach is useful in applications where images are used to supply information to specialists who will choose suitable actions. An artificial neural classifier aids a fuzzy decision support system to deal with uncertainty and imprecision present in available information. Advantages of both techniques are exploited complementarily. As an example, this method was applied in automatic focus checking and adjustment in video monitor manufacturing. Copyright © 2005 IFAC.

Hysteroscopic myomectomy in a submucous fibroid 3 mm from the serosa: A case report - Case report from the endoscopy service of Ginendo-RJ

This is a case report of a 39-year-old black woman, nulliparous, married who presented a heavy menstrual flow with clots and dysmenorrhea. Gynaecological examination of the uterus revealed RVF, mobility, no pain, slight enlargement, and right displacement. Magnetic resonance imaging (MRI) of the pelvis showed a 40 mm submucous fibroid with intramural component less than 50%, type 1, with a 3 mm distance from serosa. In an office hysteroscopy, it was noted a 40 mm submucous fibroid with an intramural component with less than 50%, type 1, classified in STEP-W submucous fibroids classification as a Score 6, Group II. The patient was submitted to partial hysteroscopic myomectomy, removing 60% of the fibroid volume in a 48.75-minute surgery. GnRH analogue was indicated for 3 months before another intervention. In the second evaluation MRI revealed a 22 mm-fibroid with intramural component more than 50%, type 2, with a 7 mm distance from serosa. Hysteroscopy found a 20 mm submucous fibroid, with intramural component more than 50%, type 2, Score 4, Group I on STEP-W classification. The patient was submitted to a second hysteroscopic myomectomy with complete removal and 10.5 minutes operating time, without complications. © 2006 Springer-Verlag.

Video target tracking by using competitive neural networks

A target tracking algorithm able to identify the position and to pursuit moving targets in video digital sequences is proposed in this paper. The proposed approach aims to track moving targets inside the vision field of a digital camera. The position and trajectory of the target are identified by using a neural network presenting competitive learning technique. The winning neuron is trained to approximate to the target and, then, pursuit it. A digital camera provides a sequence of images and the algorithm process those frames in real time tracking the moving target. The algorithm is performed both with black and white and multi-colored images to simulate real world situations. Results show the effectiveness of the proposed algorithm, since the neurons tracked the moving targets even if there is no pre-processing image analysis. Single and multiple moving targets are followed in real time.

A video-based biometric authentication for e-learning web applications

In the last years there was an exponential growth in the offering of Web-enabled distance courses and in the number of enrolments in corporate and higher education using this modality. However, the lack of efficient mechanisms that assures user authentication in this sort of environment, in the system login as well as throughout his session, has been pointed out as a serious deficiency. Some studies have been led about possible biometric applications for web authentication. However, password based authentication still prevails. With the popularization of biometric enabled devices and resultant fall of prices for the collection of biometric traits, biometrics is reconsidered as a secure remote authentication form for web applications. In this work, the face recognition accuracy, captured on-line by a webcam in Internet environment, is investigated, simulating the natural interaction of a person in the context of a distance course environment. Partial results show that this technique can be successfully applied to confirm the presence of users throughout the course attendance in an educational distance course. An efficient client/server architecture is also proposed. © 2009 Springer Berlin Heidelberg.

Hysteroscopic myomectomy in a submucous fibroid near from tubal ostia and 5 mm from the serosa: A case report from the Endoscopy Service of Ginendo-RJ

This is a case report of a 27-year-old white woman, nuliparous, single, who presented a heavy menstrual flow with clots, dysmenorrhoea and anaemia. Gynaecological examination of the uterus revealed anteverted position, mobility, no pain, slight enlargement and right displacement. Magnetic resonance imaging of the pelvis showed a 29-mm submucous fibroid with intramural component more than 50%, type 2, in the posterior wall, with a 5-mm distance from serosa. In office hysteroscopy, a 30-mm submucous fibroid with an intramural component with more than 50%, type 2, near around 5 mm from left tubal ostia, classified in STEP-W submucous fibroids classification as score 6, group II, was noted. GnRH analogue was indicated for 3 months before intervention to treat anaemia. The patient was submitted to hysteroscopic myomectomy with direct mobilisation technique, with the fibroid completely removed without complications in a surgery which lasted for 52 min and 20 s. © 2008 Springer-Verlag.

Bothropstoxin-I reduces evoked acetylcholine release from rat motor nerve terminals: Radiochemical and real-time video-microscopy studies

Understanding the biological activity profile of the snake venom components is fundamental for improving the treatment of snakebite envenomings and may also contribute for the development of new potential therapeutic agents. In this work, we tested the effects of BthTX-I, a Lys49 PLA2 homologue from the Bothrops jararacussu snake venom. While this toxin induces conspicuous myonecrosis by a catalytically independent mechanism, a series of in vitro studies support the hypothesis that BthTX-I might also exert a neuromuscular blocking activity due to its ability to alter the integrity of muscle cell membranes. To gain insight into the mechanisms of this inhibitory neuromuscular effect, for the first time, the influence of BthTX-I on nerve-evoked ACh release was directly quantified by radiochemical and real-time video-microscopy methods. Our results show that the neuromuscular blockade produced by in vitro exposure to BthTX-I (1 μM) results from the summation of both pre- and postsynaptic effects. Modifications affecting the presynaptic apparatus were revealed by the significant reduction of nerve-evoked [3H]-ACh release; real-time measurements of transmitter exocytosis using the FM4-64 fluorescent dye fully supported radiochemical data. The postsynaptic effect of BthTX-I was characterized by typical histological alterations in the architecture of skeletal muscle fibers, increase in the outflow of the intracellular lactate dehydrogenase enzyme and progressive depolarization of the muscle resting membrane potential. In conclusion, these findings suggest that the neuromuscular blockade produced by BthTX-I results from transient depolarization of skeletal muscle fibers, consequent to its general membrane-destabilizing effect, and subsequent decrease of evoked ACh release from motor nerve terminals. © 2012 Elsevier Ltd.

A rank aggregation framework for video multimodal geocoding

This paper proposes a rank aggregation framework for video multimodal geocoding. Textual and visual descriptions associated with videos are used to define ranked lists. These ranked lists are later combined, and the resulting ranked list is used to define appropriate locations for videos. An architecture that implements the proposed framework is designed. In this architecture, there are specific modules for each modality (e.g, textual and visual) that can be developed and evolved independently. Another component is a data fusion module responsible for combining seamlessly the ranked lists defined for each modality. We have validated the proposed framework in the context of the MediaEval 2012 Placing Task, whose objective is to automatically assign geographical coordinates to videos. Obtained results show how our multimodal approach improves the geocoding results when compared to methods that rely on a single modality (either textual or visual descriptors). We also show that the proposed multimodal approach yields comparable results to the best submissions to the Placing Task in 2012 using no extra information besides the available development/training data. Another contribution of this work is related to the proposal of a new effectiveness evaluation measure. The proposed measure is based on distance scores that summarize how effective a designed/tested approach is, considering its overall result for a test dataset. © 2013 Springer Science+Business Media New York.

Ipsis video litteris: processos e procedimentos artísticos da escrita na televisão - videografia

Pós-graduação em Artes - IA

Curva de aprendizado da ovariohisterectomia video-assistida e da miniceliotomia associada à técnica do gancho de snook em gatas (Felis catus, Linnaeus, 1758)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Instrumento nuevo en el análisis social: ENTRE-RIELES": etapas y desarrollo de una experiencia en video interdisciplinaria"

Incluye Bibliografía

Entre Rieles: una experiencia interdisciplinaria en video sobre juventud popular urbana

Incluye Bibliografía

Estudo comparativo entre as técnicas de video-toracoscopia e toracotomia para fenestração de disco intervertebral em cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)