27 research outputs found

    Uniqueness and Nondegeneracy of Ground States for (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

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    We prove uniqueness of ground state solutions Q=Q(∣x∣)≥0Q = Q(|x|) \geq 0 for the nonlinear equation (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1}= 0 in R\mathbb{R}, where 0<s<10 < s < 1 and 0<α<4s1−2s0 < \alpha < \frac{4s}{1-2s} for s<1/2s < 1/2 and 0<α<∞0 < \alpha < \infty for s≥1/2s \geq 1/2. Here (−Δ)s(-\Delta)^s denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for s=1/2s=1/2 and α=1\alpha=1 in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator L+=(−Δ)s+1−(α+1)QαL_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha is nondegenerate; i.\,e., its kernel satisfies ker L+=span {Q′}\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}. This result about L+L_+ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page

    Group B Streptococcus GAPDH Is Released upon Cell Lysis, Associates with Bacterial Surface, and Induces Apoptosis in Murine Macrophages

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    Glyceraldehyde 3-phosphate dehydrogenases (GAPDH) are cytoplasmic glycolytic enzymes that, despite lacking identifiable secretion signals, have been detected at the surface of several prokaryotic and eukaryotic organisms where they exhibit non-glycolytic functions including adhesion to host components. Group B Streptococcus (GBS) is a human commensal bacterium that has the capacity to cause life-threatening meningitis and septicemia in newborns. Electron microscopy and fluorescence-activated cell sorter (FACS) analysis demonstrated the surface localization of GAPDH in GBS. By addressing the question of GAPDH export to the cell surface of GBS strain NEM316 and isogenic mutant derivatives of our collection, we found that impaired GAPDH presence in the surface and supernatant of GBS was associated with a lower level of bacterial lysis. We also found that following GBS lysis, GAPDH can associate to the surface of many living bacteria. Finally, we provide evidence for a novel function of the secreted GAPDH as an inducer of apoptosis of murine macrophages

    A Framework combining Agile, UCD and SOA approaches for Collaborative Disaster Management system Design

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    International audienceDisaster management is a special type of human complex organisation in which heterogeneous human actors belonging to different authorities collaborate and work together with the shared aim to solve, or at least reduce, the disaster situation. Thus, the collaboration in this case within team members and with other teams operating at the disaster site(s) is very critical and complex; the achievement of the desired goal heavily depends on this collaboration. Interactive and easy to use services in these scenarios are very valuable and necessary as they can improve collaboration, coordination, and communication amongst team(s) to achieve the desired goals. For this purpose, in this paper, we propose a novel design framework for complex disaster management systems. We combine agile characteristics and principles, user-centred techniques and service-oriented architecture paradigm. Our aim is to take into account the needs of the disaster managers in an iterative development process, to improve the human actors' involvement in the design projects, to offer the possibility to accept any changes in order to produce highly usable and interactive service-based collaborative services
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