894 resultados para Newton-Krylov
Resumo:
The present morphological study of A. glabratus was based on the observation of shell, radula, renal region and genitalia of 50 specimens having a shell diameter of 18 mm. In this summary we record the data pertaining to the chracteristics that can be used in systematics. The numerals refere to the mean and their standard deviation; no special reference being made, they correspond to length measurements. Shell: 18 mm in diameter, 5.59 ± 0.24 mm in greatest width, 5 to 6 whorls. Right side umbilicated, left one weakly depressed. Last whorl about thrice as tall as the penultimate one at the aperture, the measurements being taken on the right side. Aperture perpendicular or a little oblique. Body, extended: 47.06 ± 3.31 mm. Renal tube: Narrow and elongated, 23.84 ± 1.90 mm, showing a pigmented ridge along its ventral surface. Ovotestis: 12.78 ± 1.50 mm. Mainly trifurcate diverticula attaching in fan-like manner to the collecting canal (this arrangement is seen to best advantage in the cephalic middle of the ovotestis). The collecting canal greatly swells at the cephalic end, narrowing suddenly as it leaves the ovotestis. Ovisperm duct: 13.70 ± 1.68 mm, including the non-unwound seminal vesicle. The latter, situated about 1 mm from the beginning af the ovisperm duct, was 1.14 ± 0.29 mm in greatest diameter, and is beset by numerous short diverticula. Sperm duct: 14.16 ± 1.27 mm, pursuing a sinous course along the oviduct. Prostate: Prostate duct 5.53 ± 0.74 mm, collecting a row of long diverticula, the latter 21.6 ± 3.5 in number. Last diverticulum generally simple or bifurcate, penultimate generally arborescent, bifurcate or simple, antepenultimate nearly always arborescent, the remaining ones arborescent. The arborescent diverticula frequently give off secondary branches. Vas deferens: 17.50 ± 2.05 mm. The ratio vas deferens/vergic sac was 4.7 ± 0.6. Verge: 3.70 ± 0.54 mm long, 0.12 ± 0.03 mm wide. Free end tapering to a point where the sperm canal opens. No penial stylet. Vergic sac: 3.77 ± 0.50 mm long, 0.19 ± 0.01 mm wide. The length ratio vergic sac/preputium was 1 ± 0.02. Preputium: Deeply pigmented, 3.79 ± 0.40 mm long, 0.89 ± 0.12 mm wide in the middle. Muscular diaphragm between it and the vergic sac. Two muscular pilasters along its lateral walls. Oviduct: 10.24 ± 1.29 mm, suddenly swollen at the cephalic end so that it forms a folded pouch capping the beginning of the uterus. Uterus: 10.58 ± 1.18 mm. Vagina: 2.06 ± 0.15 mm long, 0.32 ± 0.05 mm wide, showing a swelling at its caudal portion, just above the opening of the spermathecal duct. Spermatheca: 1.57 ± 0.41 mm long, 0.92 ± 0.23 mm wide. Spermathecal duct 1.15 ± 0.23 mm. Radula: 125 to 163 rows of teeth (mean 141.4 ± 9.8). Radula formula 27-1-27 to 34-1-34 (mean 30.9 ± 1.7).
Resumo:
A morphological study was done on A. nigricans, based on the observation of shell, radula, renal region and genitalia of 50 specimens measuring 18 mm in diameter. The data obtained are to be compared with those recorded in our previous paper (PARAENSE & DESLANDES, 1955) on A. glabratus. The characteristics common to both species will not be mentioned here. The numerals refere to the means and their standard deviations: no special reference being done, they correspond to length measurementes. Shell - 18 mm in diameter, 6.37 ± 0.29 mm in greatest width, 6 whorls. Prevailing colur ferruginous sepia, a minority of olivaceous, ochreous, nigrescent and deeply black specimens being found. Right side variously depressed, umbilicated, 1.5 to 3.5 mm deep from the bottom of the umblicus to the highest level of the last whorl. Left side more depressed than the right one, broadly concave, 1.5 to 3.5 mm deep. Both sides show a varously distinct keel, that looks sharper at the left. Aperture deltoid, varying in outline and width. Body, extended - 60.26 ± 3.62 mm, less pigmented than in glabratus. Renal tube - 30.68 ± 1.69 mm, showing neither ridge nor pigmented line along its ventral surface, this negative character affording a sure means of separation from glabratus. Ovotestis - 14.48 ± 1.93 mm. Ovisperm duct - 13.04 ± 1.60 mm, including the non-unwound seminal vesicle. The latter was 0.97 ± 0,21 mm in greatest width. Carrefour - Resembling that of glabratus. Sperm duct - 21.36 ± 1.53 mm. Prostate - Prostate duct 7.14 ± 0.74 mm, collecting a row of long diverticula numbering 19.6 ± 3.1 and more separate than in glabratus. Last diverticulum generally bifurcate or arborescent, the remaining ones arborescent. Vas deferens - 28.68 ± 1.38. Ratio vas deferens/vergic sac = 6.8±0.8. Verge - 3.08 ± 0.28 mm long, 0.11 ± 0.02 mm wide. Vergic sac - 3.07 ± 0.28 mm long, about 0.20 mm wide. Ratio vergic sac/preputium = 0.84 ± 0.12. Preputium - 3.69 ± 0.47 mm long, 0.85 ± 0.10 mm wide. Albumen gland - Resembling taht of glabratus. Oviduct - 16.26 ± 1.41 mm, swollen at the cephalic end. Uterus - 13.24 ± 1.19 mm. Vagina - 1.70 ± 0.22 mm, swolen at the caudal portion. Spermatheca - 2.78 ± 0.40 mm long, 0.86 ± 0.16 mm wide. Spermathecal duct 1.11 ± 0.20 mm. Radula - 125 to 168 horizontal rows of teeth (mean 153.9 ± 8.4). Radula formula 28-1-28 to 36-1-36 (mean 31.8 ± 1.9). Mode formula 31-1-31. The morphological characteristics of the renal region and shell, and the great body length in the same condition of shell diameter, distinguish A. nigricans from the most related species A. glabratus, giving support to considering it a good species from a txonomic or phenotypic standpoint (morphospecies).
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Foram feitas provas de cruzamento entre espécimes de uma população de A. glabratus e de outra de A. nigricans, utilizando o fator de albinismo como mercador genético. O resultado dessas provas revelou completo isolamento reprodutivo entre ambas, permitindo separá-las como boas espécies de acôrdo com o critério biológico.
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Os autores analisam pormenorizadamente o sistema soro-hematia formolizada no qual se processa a aglutino-sedimentação (Fenômeno de Rubino). Cada fase do referido sistema é investigada do ponto de vista físico-químico. Os dados obtidos são aproveitados pelos autores na elaboração de um sistema análogo, porém, com parâmetros próprios diferentes dos fixados por Rubino. Escolheu-se como evidência do fenômeno não a alutino-sedimentação função do tempo, porém, o aspecto da massa globular sedimentada após 24 horas a ± 10ºC (Hemodispersão sedimentar). A nova técnica proposta, aplicada sistematicamente, permitiu aos autores concluírem a) não há 'especificidade" correlacionada com enfermidades; b) o fenômeno resulta da atividade combinada de gamaglobulinas como dipolos, íons positivos do meio e polaridade propícia das hematias formolizadas; c)o aumento das gamaglobulinas séricas, sobretudo daquelas de ponto iso-elétrico do pH sanguíneo, determina o fenômeno, independentemente da causa mórbida que originou a hipergamaglobulinemia; d) sobretudo na lepra lepromatosa, o aumento das referidas gamaglobulinas é muito freqüente, e mantém-se muito tempo mesmo após regressão clínica da doença. É sugerida uma explicação para este último fato; e)os autores também referem uma atividade especial do formol sobre os soros reatores, propondo uma hipótese para a mesma.
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La "Phoronomia", primer libro de mecánica escrito tras los "Principia", es representativo del proceso de transición que transformó la dinámica a principios del XVIII y que concluye con la "Mecánica" de Euler (1736). Está escrita en estilo geométrico y algebraico, y mezcla los conceptos y métodos de Leibniz y Newton de forma idiosincrásica. En esta obra se encuentra por primera vez la segunda ley de Newton escrita en la forma en que hoy la conocemos, así como un intento de construcción de la estática y la dinámica de sólidos y fluidos basado en reglas generales diferenciales.
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El treball consisteix en l'estudi d'alguns aspectes de l'obra del metge, físic, filòsof i teòleg anglès Walter Charleton (1620-1707), en el marc de la història intel•lectual a Anglaterra durant la segona meitat del segle XVII. Aquest període, que culmina en el sistema de Newton, es configura a través d'un conjunt de factors socials, polítics, intel•lectuals i religiosos, que van donar lloc a la consolidació del mecanicisme com a filosofia natural. En aquest context, Charleton és considerat com el principal introductor de l'atomisme de Gassendi a Anglaterra. Més concretament, el treball analitza l'anomenat voluntarisme teològic en la figura de Charleton, i la seva teologia natural com a fonament de l'atomisme, remarcant que el discurs teològic està implícit en el discurs físic.
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Les xarxes híbrides satèl·lit-terrestre ofereixen connectivitat a zones remotes i aïllades i permeten resoldre nombrosos problemes de comunicacions. No obstant, presenten diversos reptes, ja que realitzen la comunicació per un canal mòbil terrestre i un canal satèl·lit contigu. Un d'aquests reptes és trobar mecanismes per realitzar eficientment l'enrutament i el control de flux, de manera conjunta. L'objectiu d'aquest projecte és simular i estudiar algorismes existents que resolguin aquests problemes, així com proposar-ne de nous, mitjançant diverses tècniques d'optimització convexa. A partir de les simulacions realitzades en aquest estudi, s'han analitzat àmpliament els diversos problemes d'enrutament i control de flux, i s'han avaluat els resultats obtinguts i les prestacions dels algorismes emprats. En concret, s'han implementat de manera satisfactòria algorismes basats en el mètode de descomposició dual, el mètode de subgradient, el mètode de Newton i el mètode de la barrera logarítmica, entre d'altres, per tal de resoldre els problemes d'enrutament i control de flux plantejats.
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De larvas e pupas de Musca domestica, Chrysomya albiceps, Cochliomyia homivorax, Stomoxys calcitrans e Syntesiomyia nudiseta coletadas em diversos ambiente, em São Paulo, Paraná, Mato Grosso, Mato Grosso do Sul e Minas Gerais, foram obtidas dez espécies de microhimenópteros parasitóides da supermamília Chalcidoidea, algumas assinaladas pela primeira vez no Brasil.
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In this paper, we develop numerical algorithms that use small requirements of storage and operations for the computation of invariant tori in Hamiltonian systems (exact symplectic maps and Hamiltonian vector fields). The algorithms are based on the parameterization method and follow closely the proof of the KAM theorem given in [LGJV05] and [FLS07]. They essentially consist in solving a functional equation satisfied by the invariant tori by using a Newton method. Using some geometric identities, it is possible to perform a Newton step using little storage and few operations. In this paper we focus on the numerical issues of the algorithms (speed, storage and stability) and we refer to the mentioned papers for the rigorous results. We show how to compute efficiently both maximal invariant tori and whiskered tori, together with the associated invariant stable and unstable manifolds of whiskered tori. Moreover, we present fast algorithms for the iteration of the quasi-periodic cocycles and the computation of the invariant bundles, which is a preliminary step for the computation of invariant whiskered tori. Since quasi-periodic cocycles appear in other contexts, this section may be of independent interest. The numerical methods presented here allow to compute in a unified way primary and secondary invariant KAM tori. Secondary tori are invariant tori which can be contracted to a periodic orbit. We present some preliminary results that ensure that the methods are indeed implementable and fast. We postpone to a future paper optimized implementations and results on the breakdown of invariant tori.
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We obtain a new series of integral formulae for symmetric functions of curvature of a distribution of arbitrary codimension (an its orthogonal complement) given on a compact Riemannian manifold, which start from known formula by P.Walczak (1990) and generalize ones for foliations by several authors: Asimov (1978), Brito, Langevin and Rosenberg (1981), Brito and Naveira (2000), Andrzejewski and Walczak (2010), etc. Our integral formulae involve the co-nullity tensor, certain component of the curvature tensor and their products. The formulae also deal with a number of arbitrary functions depending on the scalar invariants of the co-nullity tensor. For foliated manifolds of constant curvature the obtained formulae give us the classical type formulae. For a special choice of functions our formulae reduce to ones with Newton transformations of the co-nullity tensor.
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Tumor-associated macrophages (TAMs) invade the tumor stroma in many cancers, yet their role is incompletely understood. To visualize and better understand these critical cells in tumor progression, we screened a portfolio of rationally selected, injectable agents to image endogenous TAMs ubiquitously in three different cancer models (colon carcinoma, lung adenocarcinoma, and soft tissue sarcoma). AMTA680, a functionally derivatized magneto-fluorescent nanoparticle, labeled a subset of myeloid cells with an "M2" macrophage phenotype, whereas other neighboring cells, including tumor cells and a variety of other leukocytes, remained unlabeled. We further show that AMTA680-labeled endogenous TAMs are not altered and can be tracked noninvasively at different resolutions and using various imaging modalities, e.g., fluorescence molecular tomography, magnetic resonance imaging, and multiphoton and confocal intravital microscopy. Quantitative assessment of TAM distribution and activity in vivo identified that these cells cluster in delimited foci within tumors, show relatively low motility, and extend cytoplasmic protrusions for prolonged physical interactions with neighboring tumor cells. Noninvasive imaging can also be used to monitor TAM-depleting regimen quantitatively. Thus, AMTA680 or related cell-targeting agents represent appropriate injectable vehicles for in vivo analysis of the tumor microenvironment.
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Monocytes serve as a central defense system against infection and injury but can also promote pathological inflammatory responses. Considering the evidence that monocytes exist in at least two subsets committed to divergent functions, we investigated whether distinct factors regulate the balance between monocyte subset responses in vivo. We identified a microRNA (miRNA), miR-146a, which is differentially regulated both in mouse (Ly-6C(hi)/Ly-6C(lo)) and human (CD14(hi)/CD14(lo)CD16(+)) monocyte subsets. The single miRNA controlled the amplitude of the Ly-6C(hi) monocyte response during inflammatory challenge whereas it did not affect Ly-6C(lo) cells. miR-146a-mediated regulation was cell-intrinsic and depended on Relb, a member of the noncanonical NF-κB/Rel family, which we identified as a direct miR-146a target. These observations not only provide mechanistic insights into the molecular events that regulate responses mediated by committed monocyte precursor populations but also identify targets for manipulating Ly-6C(hi) monocyte responses while sparing Ly-6Clo monocyte activity.
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We evaluate the performance of different optimization techniques developed in the context of optical flowcomputation with different variational models. In particular, based on truncated Newton methods (TN) that have been an effective approach for large-scale unconstrained optimization, we develop the use of efficient multilevel schemes for computing the optical flow. More precisely, we evaluate the performance of a standard unidirectional multilevel algorithm - called multiresolution optimization (MR/OPT), to a bidrectional multilevel algorithm - called full multigrid optimization (FMG/OPT). The FMG/OPT algorithm treats the coarse grid correction as an optimization search direction and eventually scales it using a line search. Experimental results on different image sequences using four models of optical flow computation show that the FMG/OPT algorithm outperforms both the TN and MR/OPT algorithms in terms of the computational work and the quality of the optical flow estimation.