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21.
We consider the edit distance with moves on the class of words and the class of ordered trees. We first exhibit a simple tester
for the class of regular languages on words and generalize it to the class of ranked and unranked regular trees. We also show
that this distance problem is
-complete on ordered trees.
A preliminary version of this paper appeared in Proceedings of 31st International Colloquium on Automata, Languages and Programming, volume 3142 of Lecture Notes in Computer Science, pages 932–944, Springer, 2005. Work supported by ACI Sécurité Informatique: VERA of the French Ministry of research. 相似文献
22.
23.
Michel Aubourg 《电信纪事》1979,34(1-2):45-51
tem approximation technique is widely used in the study of waveguides characterized by the fundamental mode without cutoff frequency. It seems that exact justification of this approximation has never been delt with before to his knowledge. Here the author is trying to show the justification for a closed waveguide noting the difference between a quasi-TEM wave and an ordinary tem wave. 相似文献
24.
Michel Barbier 《Journal of chemical ecology》1990,16(3):743-748
The doubly cyclized bile pigment sarpedobilin (3) represents a unique case in nature. In spite of being present in trace amounts in many butterfly and moth species containing pterobilin (1) or phorcabilin (2) as the main bilin, this substance occurs as the main pigment in a restricted number of species geographically limited to Southeast Asia. We have isolated and identified sarpedobilin3 (as the dimethyl ester) as the main bile pigment fromPapilio graphium stresemani stresemani (from Ceram island, Indonesia) in the amount of ca. 0.1 mg per individual, double that found inPapilio sar-pedon orP. weiskei. We conclude thatP. sarpedon (and subspecies)P. weis-kei, andP. stresemani represent, in terms of evolution (see article), a group of closely related species. By comparison of colored wing patterns and resistance of the chromoproteins to hydrolysis by MeOH-H2SO4,P. stresemani is nearP. weiskei. The bioecological relationships of the three sarpedobilin-containing species is discussed. 相似文献
25.
Optical field concentration in low-index waveguides 总被引:1,自引:0,他引:1
We present a highly efficient optical field concentrator that is capable of confining optical field in nanometer-thin low-index media with very high optical confinement factor. The structure is made of multiple-layered low-index nanolayers embedded in high-index silicon waveguides. By creating multiple high-index-contrast interfaces, the normal field in the low-index nanolayer regions is significantly enhanced. It subsequently results in a very high optical confinement and power density in these regions. With the help of numerical simulation tools, the guiding and propagating characteristics of the new structure are studied and presented. The optimal structures have demonstrated confinement factors and normalized power densities in the range of 30%-60% and 20-160 /spl mu/m/sup -2/ for the 5-20-nm thin low-index multiple nanolayers. 相似文献
26.
This paper addresses the issue of improving the performance of memory management for real-time Java applications, building upon the real-time specification for Java (RTSJ) from the Real-Time Java Expert Group. In a first step, a collecting dynamic memory solution including both a real-time garbage collector and region-based memory management, is proposed. A thorough analysis of the parameters influencing the performance of write barriers in memory management, together with ways of improvement are then presented. Finally, the implementation of a memory management solution compliant with the RTSJ and integrating the proposed improvements is sketched. 相似文献
27.
Verena Moosbrugger-Martinz Corinne Leprince Marie-Claire Mchin Michel Simon Stefan Blunder Robert Gruber Sandrine Dubrac 《International journal of molecular sciences》2022,23(10)
The discovery in 2006 that loss-of-function mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris and can predispose to atopic dermatitis (AD) galvanized the dermatology research community and shed new light on a skin protein that was first identified in 1981. However, although outstanding work has uncovered several key functions of filaggrin in epidermal homeostasis, a comprehensive understanding of how filaggrin deficiency contributes to AD is still incomplete, including details of the upstream factors that lead to the reduced amounts of filaggrin, regardless of genotype. In this review, we re-evaluate data focusing on the roles of filaggrin in the epidermis, as well as in AD. Filaggrin is important for alignment of keratin intermediate filaments, control of keratinocyte shape, and maintenance of epidermal texture via production of water-retaining molecules. Moreover, filaggrin deficiency leads to cellular abnormalities in keratinocytes and induces subtle epidermal barrier impairment that is sufficient enough to facilitate the ingress of certain exogenous molecules into the epidermis. However, although FLG null mutations regulate skin moisture in non-lesional AD skin, filaggrin deficiency per se does not lead to the neutralization of skin surface pH or to excessive transepidermal water loss in atopic skin. Separating facts from chaff regarding the functions of filaggrin in the epidermis is necessary for the design efficacious therapies to treat dry and atopic skin. 相似文献
28.
29.
Isabelle Six Nicolas Guillaume Valentine Jacob Romuald Mentaverri Said Kamel Agns Boullier Michel Slama 《International journal of molecular sciences》2022,23(11)
The endothelium has a fundamental role in the cardiovascular complications of coronavirus disease 2019 (COVID-19). Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) particularly affects endothelial cells. The virus binds to the angiotensin-converting enzyme 2 (ACE-2) receptor (present on type 2 alveolar cells, bronchial epithelial cells, and endothelial cells), and induces a cytokine storm. The cytokines tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 have particular effects on endothelial cells—leading to endothelial dysfunction, endothelial cell death, changes in tight junctions, and vascular hyperpermeability. Under normal conditions, apoptotic endothelial cells are removed into the bloodstream. During COVID-19, however, endothelial cells are detached more rapidly, and do not regenerate as effectively as usual. The loss of the endothelium on the luminal surface abolishes all of the vascular responses mediated by the endothelium and nitric oxide production in particular, which results in greater contractility. Moreover, circulating endothelial cells infected with SARS-CoV-2 act as vectors for viral dissemination by forming clusters that migrate into the circulation and reach distant organs. The cell clusters and the endothelial dysfunction might contribute to the various thromboembolic pathologies observed in COVID-19 by inducing the formation of intravascular microthrombi, as well as by triggering disseminated intravascular coagulation. Here, we review the contributions of endotheliopathy and endothelial-cell-derived extracellular vesicles to the pathogenesis of COVID-19, and discuss therapeutic strategies that target the endothelium in patients with COVID-19. 相似文献
30.
Eveline Santos da Silva Michel Kohnen Georges Gilson Therese Staub Victor Arendt Christiane Hilger Jean-Yves Servais Emilie Charpentier Olivia Domingues Chantal J. Snoeck Markus Ollert Carole Seguin-Devaux Danielle Perez-Bercoff 《International journal of molecular sciences》2022,23(14)
SARS-CoV-2 variants raise concern because of their high transmissibility and their ability to evade neutralizing antibodies elicited by prior infection or by vaccination. Here, we compared the neutralizing abilities of sera from 70 unvaccinated COVID-19 patients infected before the emergence of variants of concern (VOCs) and of 16 vaccine breakthrough infection (BTI) cases infected with Gamma or Delta against the ancestral B.1 strain, the Gamma, Delta and Omicron BA.1 VOCs using live virus. We further determined antibody levels against the Nucleocapsid (N) and full Spike proteins, the receptor-binding domain (RBD) and the N-terminal domain (NTD) of the Spike protein. Convalescent sera featured considerable variability in the neutralization of B.1 and in the cross-neutralization of different strains. Their neutralizing capacity moderately correlated with antibody levels against the Spike protein and the RBD. All but one convalescent serum failed to neutralize Omicron BA.1. Overall, convalescent sera from patients with moderate disease had higher antibody levels and displayed a higher neutralizing ability against all strains than patients with mild or severe forms of the disease. The sera from BTI cases fell into one of two categories: half the sera had a high neutralizing activity against the ancestral B.1 strain as well as against the infecting strain, while the other half had no or a very low neutralizing activity against all strains. Although antibody levels against the spike protein and the RBD were lower in BTI sera than in unvaccinated convalescent sera, most neutralizing sera also retained partial neutralizing activity against Omicron BA.1, suggestive of a better cross-neutralization and higher affinity of vaccine-elicited antibodies over virus-induced antibodies. Accordingly, the IC50: antibody level ratios were comparable for BTI and convalescent sera, but remained lower in the neutralizing convalescent sera from patients with moderate disease than in BTI sera. The neutralizing activity of BTI sera was strongly correlated with antibodies against the Spike protein and the RBD. Together, these findings highlight qualitative differences in antibody responses elicited by infection in vaccinated and unvaccinated individuals. They further indicate that breakthrough infection with a pre-Omicron variant boosts immunity and induces cross-neutralizing antibodies against different strains, including Omicron BA.1. 相似文献