1,152 research outputs found
Deformed Harry Dym and Hunter-Zheng Equations
We study the deformed Harry Dym and Hunter-Zheng equations with two arbitrary
deformation parameters. These reduce to various other known models in
appropriate limits. We show that both these systems are bi-Hamiltonian with the
same Hamiltonian structures. They are integrable and belong to the same
hierarchy corresponding to positive and negative flows. We present the Lax pair
description for both the systems and construct the conserved charges of
negative order from the Lax operator. For the deformed Harry Dym equation, we
construct the non-standard Lax representation for two special classes of values
of the deformation parameters. In general, we argue that a non-standard
description will involve a pseudo-differential operator of infinite order.Comment: Latex file, 15 page
A Nonliearly Dispersive Fifth Order Integrable Equation and its Hierarchy
In this paper, we study the properties of a nonlinearly dispersive integrable
system of fifth order and its associated hierarchy. We describe a Lax
representation for such a system which leads to two infinite series of
conserved charges and two hierarchies of equations that share the same
conserved charges. We construct two compatible Hamiltonian structures as well
as their Casimir functionals. One of the structures has a single Casimir
functional while the other has two. This allows us to extend the flows into
negative order and clarifies the meaning of two different hierarchies of
positive flows. We study the behavior of these systems under a hodograph
transformation and show that they are related to the Kaup-Kupershmidt and the
Sawada-Kotera equations under appropriate Miura transformations. We also
discuss briefly some properties associated with the generalization of second,
third and fourth order Lax operators.Comment: 11 pages, LaTex, version to be published in Journal of Nonlinear
Mathematical Physics, has expanded discussio
Morphological Aspects And Cox-2 Expression After Exposure To 780-nm Laser Therapy In Injured Skeletal Muscle: An In Vivo Study
Background: The effectiveness of low-level laser therapy in muscle regeneration is still not well known. Objective: To investigate the effects of laser irradiation during muscle healing. Method: For this purpose, 63 rats were distributed to 3 groups: non-irradiated control group (CG); group irradiated at 10 J/cm² (G10); and group irradiated at 50 J/cm² (G50). Each group was divided into 3 different subgroups (n=7), and on days 7, 14 and 21 post-injury the rats were sacrificed. Results: Seven days post-surgery, the CG showed destroyed zones and extensive myofibrillar degeneration. For both treated groups, the necrosis area was smaller compared to the CG. On day 14 post-injury, treated groups demonstrated better tissue organization, with newly formed muscle fibers compared to the CG. On the 21st day, the irradiated groups showed similar patterns of tissue repair, with improved muscle structure at the site of the injury, resembling uninjured muscle tissue organization. Regarding collagen deposition, the G10 showed an increase in collagen synthesis. In the last period evaluated, both treated groups showed statistically higher values in comparison with the CG. Furthermore, laser irradiation at 10 J/cm2 produced a down-regulation of cyclooxygenase 2 (Cox-2) immunoexpression on day 7 post-injury. Moreover, Cox-2 immunoexpression was decreased in both treated groups on day 14. Conclusions: Laser therapy at both fluencies stimulated muscle repair through the formation of new muscle fiber, increase in collagen synthesis, and down-regulation of Cox-2 expression.185395401Minamoto, V.B., Bunho, S.R., Salvini, T.F., Regenerated rat skeletal muscle after periodic contusions (2001) Braz J Med Biol Res, 34 (11), pp. 1447-1452. , http://dx.doi.org/10.1590/S0100-879X2001001100012, PMid:11668355Baptista, J., Martins, M.D., Pavesi, V.C., Bussadori, S.K., Fernandes, K.P., Pinto, D.S., Jr., Influence of laser photobiomodulation on collagen IV during skeletal muscle tissue remodeling after injury in rats (2011) Photomed Laser Surg, 29 (1), pp. 11-17. , http://dx.doi.org/10.1089/pho.2009.2737, PMid:20701543Renno, A.C., Toma, R.L., Feitosa, S.M., Fernandes, K., Bossini, P.S., De Oliveira, P., Comparative effects of low-intensity pulsed ultrasound and low-level laser therapy on injured skeletal muscle (2011) Photomed Laser Surg, 29 (1), pp. 5-10. , http://dx.doi.org/10.1089/pho.2009.2715, PMid:21166589Pinheiro, A.L., Soares, L.G., Aciole, G.T., Correia, N.A., Barbosa, A.F., Ramalho, L.M., Light microscopic description of the effects of laser phototherapy on bone defects grafted with mineral trioxide aggregate, bone morphogenetic proteins, and guided bone regeneration in a rodent model (2011) J Biomed Mater Res A, 98 (2), pp. 212-221. , http://dx.doi.org/10.1002/jbm.a.33107, PMid:21548072Amaral, A.C., Parizotto, N.A., Salvini, T.F., Dose-dependency of low-energy HeNe laser effect in regeneration of skeletal muscle in mice (2001) Lasers Med Sci, 16 (1), pp. 44-51. , PMid:11486338Cressoni, M.D., Dib Giusti, H.H., Casarotto, R.A., Anaruma, C.A., The effects of a 785-nm AlGaInP laser on the regeneration of rat anterior tibialis muscle after surgicallyinduced injury (2008) Photomed Laser Surg, 26 (5), pp. 461-466. , http://dx.doi.org/10.1089/pho.2007.2150, PMid:18800950Pires, D., Xavier, M., Araújo, T., Silva, J.A., Jr., Aimbire, F., Albertini, R., Low-level laser therapy (LLLT780 nm) acts differently on mRNA expression of antiand pro-inflammatory mediators in an experimental model of collagenaseinducel tendinitis in rat (2011) Lasers Med Sci, 26, pp. 85-94. , http://dx.doi.org/10.1007/s10103-010-0811-zAlves, A.N., Fernandes, K.P.S., Melo, C.A.V., Yamaguchi, R.Y., França, C.M., Teixeira, D.F., Modulating effect of Low-level laser therapy on fibrosis in the repair process of the tibialis anterior muscle in rats (2014) Lasers Med Sci, 29 (2), pp. 813-821. , http://dx.doi.org/10.1007/s10103-013-1428-9, PMid:23982721Almeida, P., Lopes-Martins, R.A.B., De Marchi, T., Tomazoni, S.S., Albertini, R., Correa, J.C.F., Red (660nm) and infrared (830nm) low-level laser therapy in skeletal muscle fatigue in humans: What is better? (2012) Lasers Med Sci, 27, pp. 453-458. , http://dx.doi.org/10.1007/s10103-011-0957-3Brunelli, R.M., Rodrigues, N.C., Ribeiro, D.A., Fernandes, K., Magri, A., Assis, L., The effects of 780-nm low-level laser therapy on muscle healing process after cryolesion (2014) Lasers Med Sci, 29 (1), pp. 91-96. , http://dx.doi.org/10.1007/s10103-013-1277-6, PMid:23407900Rodrigues, N.C., Brunelli, R., De Araújo, H.S., Parizotto, N.A., Renno, A.C., Low-level laser therapy (LLLT) (660nm) alters gene expression during muscle healing in rats (2013) J Photochem Photobiol B, 120, pp. 29-35. , http://dx.doi.org/10.1016/j.jphotobiol.2013.01.002, PMid:23416710Shefer, G., Partridge, T.A., Heslop, L., Gross, J.G., Oron, U., Halevy, O., Low-energy laser irradiation promotes the survival and cell cycle entry of skeletal muscle satellite cells (2002) J Cell Sci, 115, pp. 1461-1469. , PMid:11896194Bossini, P.S., Renno, A.C., Ribeiro, D.A., Fangel, R., Peitl, O., Zanotto, E.D., Biosilicate(R) and low-level laser therapy improve bone repair in osteoporotic rats (2011) J Tissue Eng Regen Med, 5 (3), pp. 229-237. , http://dx.doi.org/10.1002/term.309, PMid:20925130Silveira, P.C., Silva, L.A., Fraga, D.B., Freitas, T.P., Streck, E.L., Pinho, R., Evaluation of mitochondrial respiratory chain activity in muscle healing by low-level laser therapy (2009) J Photochem Photobiol B, 95 (2), pp. 89-92. , http://dx.doi.org/10.1016/j.jphotobiol.2009.01.004, PMid:19232497Tim, C.R., Pinto, K.N., Rossi, B.R., Fernandes, K., Matsumoto, M.A., Parizotto, N.A., Low-level laser therapy enhances the expression of osteogenic factors during bone repair in rats (2014) Lasers Med Sci, 29 (1), pp. 147-156. , http://dx.doi.org/10.1007/s10103-013-1302-9, PMid:23515631Rizzi, C.F., Mauriz, J.L., Freitas Correa, D.S., Moreira, A.J., Zettler, C.G., Filippin, L.I., Effects of low-level laser therapy (LLLT) on the nuclear factor (NF)-kappaB signaling pathway in traumatized muscle (2006) Lasers Surg Med, 38 (7), pp. 704-713. , http://dx.doi.org/10.1002/lsm.20371, PMid:16799998Carmeli, E., Moas, M., Reznick, A.Z., Coleman, R., Matrix metalloproteinases and skeletal muscle: A brief review (2004) Muscle Nerve, 29 (2), pp. 191-197. , http://dx.doi.org/10.1002/mus.10529, PMid:14755482Matsumoto, M.A., Ferino, R.V., Monteleone, G.F., Ribeiro, D.A., Low-level laser therapy modulates cyclo-oxygenase-2 expression during bone repair in rats (2009) Lasers Med Sci, 24 (2), pp. 195-201. , http://dx.doi.org/10.1007/s10103-008-0544-4, PMid:18309458Albertini, R., Aimbire, F., Villaverde, A.B., Silva, J.A., Jr., Costa, M.S., COX-2 mRNA expression decreases in the subplantar muscle of rat paw subjected to carrageenan-induced inflammation after low level laser therapy (2007) Inflamm Res, 56 (6), pp. 228-229. , http://dx.doi.org/10.1007/s00011-007-6211-6, PMid:17607546Byrnes, K.R., Wu, X., Waynant, R.W., Ilev, I.K., Anders, J.J., Low power laser irradiation alters gene expression of olfactory ensheathing cells in vitro (2005) Lasers Surg Med, 37 (2), pp. 161-171. , http://dx.doi.org/10.1002/lsm.20202, PMid:16037971Moore, P., Ridgway, T.D., Higbee, R.G., Howard, E.W., Lucroy, M.D., Effect of wavelength on low-intensity laser irradiation-stimulated cell proliferation in vitro (2005) Lasers Surg Med, 36 (1), pp. 8-12. , http://dx.doi.org/10.1002/lsm.20117, PMid:15662631Demidova-Rice, T.N., Salomatina, E.V., Yaroslavsky, A.N., Herman, I.M., Hamblin, M.R., Low-level light stimulates excisional wound healing in mice (2007) Lasers Surg Med, 39 (9), pp. 706-715. , http://dx.doi.org/10.1002/lsm.20549, PMid:17960752 PMCid:PMC293579
Dinâmica de fenilalanina amonia-liase e peroxidase em feijão-caupi tratado com Acibenzolar-S-Metil.
O aumento na atividade das enzimas fenilalanina amônia-liase (FAL) e peroxidase tem sido associado a respostas inespecíficas de defesa vegetal. Objetivou-se com este trabalho verificar aumento na atividade dessas enzimas em plantas de feijão-caupi [Vigna unguiculata (L.) Walp.], cv. Rouxinol, oriundas de sementes tratadas com acibenzolar-S-metil (ASM) e desafiadas por Macrophomina phaseolina, agente causal da podridão cinzenta do caule. O experimento foi organizado em delineamento inteiramente casualizado, em arranjo fatorial 4 x 9 (tratamentos versus tempo de coleta) e três repetições. Os tratamentos foram representados pelo indutor (ASM), indutor + patógeno (ASM+MP), água + patógeno (H2O+MP) e testemunha absoluta (H2O). Os tempos de coleta foram: 0, 12, 24, 36, 48, 60, 72, 84 e 96 horas, após a semeadura e inoculação. Cada repetição foi representada por três sementes/plântulas. A atividade da FAL foi aumentada pela aplicação de ASM, especialmente nas 60 horas após a inoculação, sendo o mesmo verificado para peroxidase às 72 horas
Detecção de Macrophomina phaseolina em sementes de feijão-caupi.
A podridão cinzenta do caule do feijão-caupi (Vigna unguiculata (L.) Walp.), causada por Macrophomina phaseolina (Tassi) Goid., é uma das mais importantes doenças fúngicas da cultura. O patógeno é eficientemente transmitido pelas sementes, o que representa um risco elevado de disseminação do mesmo para áreas indenes. A esta realidade, pode-se acrescer aquela que resulta do aumento da distribuição de isolados entre áreas produtoras, constituindo-se em uma maior ameaça ao cultivo, pelo aumento da variabilidade patogênica. Este trabalho objetivou avaliar a qualidade sanitária das sementes em 119 amostras, originárias das Regiões Norte e Nordeste do Brasil, com foco à detecção de M. phaseolina. Empregou-se o método do papel de filtro com restrição hídrica (NaCl a 0,8Mpa), sendo utilizadas 400 sementes/amostra. O fungo M. phaseolina foi detectado em 62% das amostras analisadas, sendo as maiores incidências verificadas naquelas originadas dos Estados da Paraíba, Piauí, Pará e Bahia, com valores médios de 25%, 12%, 19% e 10%, respectivamente. Observou-se, ainda, diferença na incidência do patógeno considerando a cor do tegumento. As sementes com tegumento branco apresentaram as maiores médias (24%), quando comparadas com as de tegumento marrom (1%) e creme (0,5%)
The genetic structure and connectivity in two sympatric rodent species with different life histories are similarly affected by land use disturbances
The negative impact of habitat fragmentation due to human activities may be different in different species that co-exist in the same area, with consequences on the development of environmental protection plans. Here we aim at understanding the effects produced by different natural and anthropic landscape features on gene flow patterns in two sympatric species with different specializations, one generalist and one specialist, sampled in the same locations. We collected and genotyped 194 wood mice (generalist species) and 199 bank voles (specialist species) from 15 woodlands in a fragmented landscape characterized by different potential barriers to dispersal. Genetic variation and structure were analyzed in the two species, respectively. Effective migration surfaces, isolation-by-resistance (IBR) analysis, and regression with randomization were used to investigate isolation-by-distance (IBD) and the relative importance of land cover elements on gene flow. We observed similar patterns of heterozygosity and IBD for both species, but the bank vole showed higher genetic differences among geographic areas. The IBR analysis suggests that (i) connectivity is reduced in both species by urban areas but more strongly in the specialist bank vole; (ii) cultivated areas act as dispersal corridors in both species; (iii) woodlands appear to be an important factor in increasing connectivity in the bank vole, and less so in the wood mouse. The difference in dispersal abilities between a generalist and specialist species was reflected in the difference in genetic structure, despite extensive habitat changes due to human activities. The negative effects of fragmentation due to the process of urbanization were, at least partially, mitigated by another human product, i.e., cultivated terrains subdivided by hedgerows, and this was true for both species
On the Nonlocal Equations and Nonlocal Charges Associated with the Harry Dym Hierarchy
A large class of nonlocal equations and nonlocal charges for the Harry Dym
hierarchy is exhibited. They are obtained from nonlocal Casimirs associated
with its bi-Hamiltonian structure. The Lax representation for some of these
equations is also given.Comment: to appear in Journal of Mathematical Physics, 17 pages, Late
Surface hardening of Al 7075 alloy by diffusion treatments of electrolytic Ni coatings
Asurface hardening process based on Ni coating and subsequent diffusion heat treatments was studiedfor Al7075 alloy. Nickel coatings with different thickness on 7075 Al alloy were obtained by electrolyticand electroless processes . Heat treatments in inert atmosphere at 500 °C and 530 °C for different timeswere performed in order to obtain surface hardening of the aluminum alloy by diffusion of Ni into thesubstrate. The effect of temperature and time on the depth of hardening was studied by SEM, EDS, Glowdischarge optical spectrometry, microhardness tests and tribological tests.Surface hardness higher than 1000 HV and depth of hardening higher than 100 mm were achieved bydiffusion of Ni layers and formation of Al3Ni2 and Al3Ni intermetallic phases .The tribological test on Al7075 alloy against a hard Cr coated steel cylinder in air showed an averagecoefficient of friction ? of about 0.5 with a wide variation range, while all the coated and treated samplesexhibited a coefficient friction of about 0.7. However, the wear scar depth of the hardened alloy is about30 times lower than that of the Al 7075 alloy
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