1,063 research outputs found

    Ultrassonografia duplex Doppler transcraniana em cães com hidrocefalia

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    Transcranial duplex Doppler ultrasound was performed in 32 conscious dogs presenting ventriculomegaly detected in B-mode, obtaining measures of lateral ventricles and resistance parameters of main cerebral arteries before and after 30 days of clinical treatment. The animals were distributed divided in two groups: group 1, dogs that presented remission or decrease of the neurological signs of the disease after clinical therapy; and group 2, dogs that displayed worsening of the neurological signs or clinical stability. The data were all presented in tables and were submitted to paired t test and to logistic regression models to evaluate the influence of the RI reduction on both groups. There was no significant influence of the variables in the B-mode. After the treatment, the mean resistive index (RI) was significantly lower for the group that presented clinical improvement. There was no significant difference of the mean RI reduction for the same artery when the right and left sides were compared. It could be concluded that transcranial duplex Doppler ultrasound is a method of cerebral hemodynamic assessment able to monitor more precisely the treatment of hydrocephalus in dogs and verify the responses.Foi realizada a ultrassonografia duplex Doppler transcraniana em 32 cães, conscientes, que apresentavam ventriculomegalia previamente detectada ao exame modo-B, para obter as medidas dos ventrículos laterais e os parâmetros de resistência das artérias cerebrais antes e depois de 30 dias de tratamento clínico. Os animais foram distribuídos em dois grupos: 1 - formado por cães que apresentaram remissão ou diminuição dos sinais clínicos após tratamento; 2 - por cães que apresentaram piora dos sinais neurológicos ou estabilidade do quadro clínico. Todos os dados foram dispostos em tabelas e submetidos ao teste t pareado e a modelos de regressão logística para avaliar a influência da redução do índice de resistividade (IR). Não foi observada influência das variáveis em modo-B. Após o tratamento, a média do IR foi significantemente menor para o grupo que apresentou melhora clínica; não houve diferença significativa da média de redução do IR para a mesma artéria quando comparados os lados direito e esquerdo. Concluiu-se que o duplex Doppler transcraniano é um métodos de avaliação hemodinâmica capaz de monitorar mais precisamente o tratamento da hidrocefalia em cães e verificar a resposta dos pacientes

    Elasto-Plastic Behavior of Aluminum Foams Subjected to Compression Loading

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    The non-linear behavior of uniform-size cellular foams made of aluminum is investigated when subjected to compressive loads while comparing numerical results obtained in the Finite Element Method software (FEM) ANSYS workbench and ANSYS Mechanical APDL (ANSYS Parametric Design Language). The numerical model is built on AUTODESK INVENTOR, being imported into ANSYS and solved by the Newton – Raphson iterative method. The most similar conditions were used in ANSYS mechanical and ANSYS workbench, as possible. The obtained numerical results and the differences between the two programs are presented and discussed.Досліджено нелінійну поведінку однорідних кліткоподібних пін, зроблених з алюмінію і підданих стиску. Порівнено числові результати, одержані двома програмними пакетами: Finite Element Method software (FEM) ANSYS workbench і ANSYS Mechanical APDL (ANSYS Parametric Design Language). Числову модель побудовано в AUTODESK INVENTOR і надалі її імпортовано в ANSYS і розв'язано за допомогою методу Ньютона - Рафсона. Використано якомога ближчі умови у вказаних пакетах. Представлено і прокоментовано одержані числові результати і спостережені відмінності між двома пакетами

    Amazonia is the primary source of Neotropical biodiversity.

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    The American tropics (the Neotropics) are the most species-rich realm on Earth, and for centuries, scientists have attempted to understand the origins and evolution of their biodiversity. It is now clear that different regions and taxonomic groups have responded differently to geological and climatic changes. However, we still lack a basic understanding of how Neotropical biodiversity was assembled over evolutionary timescales. Here we infer the timing and origin of the living biota in all major Neotropical regions by performing a cross-taxonomic biogeographic analysis based on 4,450 species from six major clades across the tree of life (angiosperms, birds, ferns, frogs, mammals, and squamates), and integrate >1.3 million species occurrences with large-scale phylogenies. We report an unprecedented level of biotic interchange among all Neotropical regions, totaling 4,525 dispersal events. About half of these events involved transitions between major environmental types, with a predominant directionality from forested to open biomes. For all taxonomic groups surveyed here, Amazonia is the primary source of Neotropical diversity, providing >2,800 lineages to other regions. Most of these dispersal events were to Mesoamerica (∼1,500 lineages), followed by dispersals into open regions of northern South America and the Cerrado and Chaco biomes. Biotic interchange has taken place for >60 million years and generally increased toward the present. The total amount of time lineages spend in a region appears to be the strongest predictor of migration events. These results demonstrate the complex origin of tropical ecosystems and the key role of biotic interchange for the assembly of regional biotas

    Long-term perturbations due to a disturbing body in elliptic inclined orbit

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    In the current study, a double-averaged analytical model including the action of the perturbing body's inclination is developed to study third-body perturbations. The disturbing function is expanded in the form of Legendre polynomials truncated up to the second-order term, and then is averaged over the periods of the spacecraft and the perturbing body. The efficiency of the double-averaged algorithm is verified with the full elliptic restricted three-body model. Comparisons with the previous study for a lunar satellite perturbed by Earth are presented to measure the effect of the perturbing body's inclination, and illustrate that the lunar obliquity with the value 6.68\degree is important for the mean motion of a lunar satellite. The application to the Mars-Sun system is shown to prove the validity of the double-averaged model. It can be seen that the algorithm is effective to predict the long-term behavior of a high-altitude Martian spacecraft perturbed by Sun. The double-averaged model presented in this paper is also applicable to other celestial systems.Comment: 28 pages, 6 figure

    Two Different Methods For Kinematic Analysis Of Head Movements Relating To Eye-head Coordination In Infants

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    Background: Kinematic analysis is a method for quantitative assessment applied in different fields of study. In the field of motor development, this analysis may promote better understanding of the acquisition and development of motor skills. Objective: To develop and compare two experimental set-ups for kinematic analysis of head movements relating to eye-head coordination (EHC) in infants. Methods: Two experimental set-ups (A and B) were tested. They differed from each other regarding the numbers and locations of the cameras, and regarding the volume of the calibration system. Results: The accuracy of the two experimental set-ups was 2.47mm, thus indicating that both can provide realistic reconstructions of the movement. The three cameras used in set-up B made it possible to view the full range of motion with at least one of the cameras. This led to improvement of the qualitative analysis and reduction of the time taken to process quantitative data, which was 33% shorter than seen with set-up A. In addition, set-up B presented a better cost-benefit relationship. Conclusions: Although both set-ups were adequate for kinematic analysis of head movements relating to EHC in infants, set-up B is more advantageous. The methodology for set-up B can be used in studies investigating head movements in either typical or atypical infants. 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(2005) Rev Bras Fisioter, 9 (1), pp. 109-112Lindquist, A.R.R., Prado, C.L., Barros, R.M.L., Mattioli, R., Costa, P.H.L., Salvini, T.F., Gait training combining partial body weight support, a treadmill, and functional electrical stimulation: Effects on poststroke gait (2007) Phys Ther, 87 (9), pp. 1144-1154Pieruccini-Faria, F., Menuchi, M.R.T.P., Vitorio, R., Gobbi, L.T.B., Stella, F., Gobbi, S., Parâmetros cinemáticos da marcha com obstáculos em idosos com doença de Parkinson, com e sem efeito da levodopa: Um estudo piloto. (2006) Rev Bras Fisioter, 10 (2), pp. 233-239Silva, J.B.F., Barros, R.M.L., Análise quantitativa e qualitativa dos sintomas de antecipação nas ações motoras de crianças. 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    A More Flavored Higgs boson in Supersymmetric models

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    A More flavored Higgs boson arises when the flavor structure encoded in SUSY extensions of the SM is transmited to the Higgs sector. The flavor-Higgs transmition mechanism can have a radiative or mixing origin, as it is illustrated with several examples, and can produce interesting Higgs signatures that can be probed at future high-energy colliders. Within the MSSM, the flavor mediation mechanism can be of radiative type, as it is realized trhough gaugino-slepton loops, which transmit the flavor structture of the soft-breaking sector to the Higgs bosons. In particular we focus on evaluating the contributions from the general trilinear terms to the lepton flavor violating Higgs (LFV) vertices. On the other hand, as an example of flavor mediation through mixing, we discuss an E_6 inspired multi-Higgs model, with an abelian flavor symmetry, where LFV as well as lepton flavor conserving Higgs effects are found to arise, though in this case at tree-level. We find that Tevatron and LHC can provide information on the flavor structure of these models through the detection of the LFV higgs mode h-> tau+mu, while NLC can perform high-precision measurements of the LFC mode h-> tau tau.Comment: 17 pages, 5 tables, 3 figures; corrected mistake in last section, results changed but conclusions remmai
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