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Enhanced antigen presentation and immunostimulation of dendritic cells using acid-degradable cationic nanoparticles.
Acid-degradable cationic nanoparticles encapsulating a model antigen (i.e., ovalbumin) were prepared by inverse microemulsion polymerization with acid-cleavable acetal cross-linkers. Incubation of these degradable nanoparticles with dendritic cells derived from bone marrow (BMDCs) resulted in the enhanced presentation of ovalbumin-derived peptides, as quantified by B3Z cells, a CD8+ T cell hybridoma. The cationic nature of the particles contributed to the increased surface endocytosis (or phagocytosis) observed with BMDCs, which is the first barrier to overcome for successful antigen delivery. The acid sensitivity of the particles served to direct more ovalbumin antigens to be processed into the appropriately trimmed peptide fragments and presented via the major histocompatibility complex (MHC) class I pathway following hydrolysis within the acidic lysosomes. It was also shown that adjuvant molecules such as unmethylated CpG oligonucleotides (CpG ODN) and anti-interleukin-10 oligonucleotides (AS10 ODN) could be co-delivered with the protein antigen for maximized cellular immune response
On Foundation of the Generalized Nambu Mechanics
We outline the basic principles of canonical formalism for the Nambu
mechanics---a generalization of Hamiltonian mechanics proposed by Yoichiro
Nambu in 1973. It is based on the notion of Nambu bracket which generalizes the
Poisson bracket to the multiple operation of higher order on
classical observables and is described by Hambu-Hamilton equations of motion
given by Hamiltonians. We introduce the fundamental identity for the
Nambu bracket which replaces Jacobi identity as a consistency condition for the
dynamics. We show that Nambu structure of given order defines a family of
subordinated structures of lower order, including the Poisson structure,
satisfying certain matching conditions. We introduce analogs of action from and
principle of the least action for the Nambu mechanics and show how dynamics of
loops (-dimensional objects) naturally appears in this formalism. We
discuss several approaches to the quantization problem and present explicit
representation of Nambu-Heisenberg commutation relation for case. We
emphasize the role higher order algebraic operations and mathematical
structures related with them play in passing from Hamilton's to Nambu's
dynamical picture.Comment: 27 page
On Mean Pose and Variability of 3D Deformable Models
International audienceWe present a novel methodology for the analysis of complex object shapes in motion observed by multiple video cameras. In particular, we propose to learn local surface rigidity probabilities (i.e., deformations), and to estimate a mean pose over a temporal sequence. Local deformations can be used for rigidity-based dynamic surface segmentation, while a mean pose can be used as a sequence keyframe or a cluster prototype and has therefore numerous applications, such as motion synthesis or sequential alignment for compression or morphing. We take advantage of recent advances in surface tracking techniques to formulate a generative model of 3D temporal sequences using a probabilistic framework, which conditions shape fitting over all frames to a simple set of intrinsic surface rigidity properties. Surface tracking and rigidity variable estimation can then be formulated as an Expectation-Maximization inference problem and solved by alternatively minimizing two nested fixed point iterations. We show that this framework provides a new fundamental building block for various applications of shape analysis, and achieves comparable tracking performance to state of the art surface tracking techniques on real datasets, even compared to approaches using strong kinematic priors such as rigid skeletons
Polymeric Separation Media: Binding of a§ unsaturated Carbonyl Compounds to Insoluble Resins through Michael Additions or Chelation of Derivatives
This is the publisher's version, also available electronically from "http://www.degruyter.com"
Inertie des stratĂ©gies de protection de lâinnovation
Cet article vise Ă intĂ©grer une dimension temporelle dans lâanalyse des choix de protection de lâinnovation. La littĂ©rature existante porte principalement sur le choix de la mĂ©thode par lâentreprise : mĂ©thodes formelles (principalement le brevet) et mĂ©thodes informelles (secret, rapiditĂ© de mise sur le marchĂ© et complexitĂ© du design). Plusieurs travaux ont mis en Ă©vidence les facteurs de choix des stratĂ©gies de protection et plus prĂ©cisĂ©ment lâimportance de la taille de lâentreprise, du recours Ă des coopĂ©rations, des dĂ©penses liĂ©es Ă la R&D, de la taille du marchĂ© et du secteur dâappartenance. Nous avons donc prolongĂ© cet apport en mobilisant des notions existantes telles que le chemin de dĂ©pendance et les phĂ©nomĂšnes dâescalade qui soulignent que les organisations font frĂ©quemment preuve d\u27une faible rĂ©activitĂ© aux transformations de leur environnement. Elles paraissent notamment avoir du mal Ă rĂ©duire des investissements dont les performances sont dĂ©cevantes. Et plus gĂ©nĂ©ralement, l\u27engagement dans un choix semble se renforcer jusqu\u27Ă parfois devenir irrĂ©versible. Il en dĂ©coule nos deux questions de recherche : dans quelle mesure le choix dâune stratĂ©gie de protection de lâinnovation favorise-t-il ultĂ©rieurement le choix dâune stratĂ©gie identique et quels sont les facteurs influençant le changement de stratĂ©gie de protection de lâinnovation ?Â
Pour y rĂ©pondre, nous avons recours Ă l\u27analyse des donnĂ©es issues des enquĂȘtes CIS 4 et CIS2006. GrĂące Ă l\u27utilisation de modĂšles logistique et probit, nous suivons l\u27Ă©volution des choix d\u27entreprises sur deux pĂ©riodes. Que les entreprises utilisent les mĂ©thodes informelles, une combinaison de mĂ©thodes (brevet et mĂ©thodes informelles) ou mĂȘme n\u27utilisent aucune mĂ©thode, nous trouvons que le choix considĂ©rĂ© est trĂšs nettement dĂ©pendant du fait qu\u27un choix identique ait Ă©tĂ© effectuĂ© dans la pĂ©riode prĂ©cĂ©dente. L\u27utilisation du brevet seul ne semble en revanche pas sujet au mĂȘme Ă©tat de dĂ©pendance, ce qui fait apparaĂźtre cette stratĂ©gie de protection comme davantage transitoire ou instable. En plus de l\u27inertie constatĂ©e dans les choix, les rĂ©sultats montrent clairement une nette diffĂ©rence entre brevet et mĂ©thodes informelles. Alors que le choix d\u27utiliser le brevet est peu sensible aux modifications d\u27autres variables, l\u27utilisation des mĂ©thodes informelles se montre quant Ă elle beaucoup plus changeante, rejoignant l\u27idĂ©e d\u27une certaine souplesse dans son utilisation
Extreme value distributions and Renormalization Group
In the classical theorems of extreme value theory the limits of suitably
rescaled maxima of sequences of independent, identically distributed random
variables are studied. So far, only affine rescalings have been considered. We
show, however, that more general rescalings are natural and lead to new limit
distributions, apart from the Gumbel, Weibull, and Fr\'echet families. The
problem is approached using the language of Renormalization Group
transformations in the space of probability densities. The limit distributions
are fixed points of the transformation and the study of the differential around
them allows a local analysis of the domains of attraction and the computation
of finite-size corrections.Comment: 16 pages, 5 figures. Final versio
Using Extreme Value Theory for Determining the Probability of Carrington-Like Solar Flares
Space weather events can negatively affect satellites, the electricity grid,
satellite navigation systems and human health. As a consequence, extreme space
weather has been added to the UK and other national risk registers. By their
very nature, extreme space weather events occur rarely and, therefore,
statistical methods are required to determine the probability of their
occurrence. Space weather events can be characterised by a number of natural
phenomena such as X-ray (solar) flares, solar energetic particle (SEP) fluxes,
coronal mass ejections and various geophysical indices (Dst, Kp, F10.7). In
this paper extreme value theory (EVT) is used to investigate the probability of
extreme solar flares. Previous work has assumed that the distribution of solar
flares follows a power law. However such an approach can lead to a poor
estimation of the return times of such events due to uncertainties in the tails
of the probability distribution function. Using EVT and GOES X-ray flux data it
is shown that the expected 150-year return level is approximately an X60 flare
whilst a Carrington-like flare is a one in a 100-year event. It is also shown
that the EVT results are consistent with flare data from the Kepler space
telescope mission.Comment: 13 pages, 4 figures; updated content following reviewer feedbac
A direct route to cyclic organic nanostructures via ring-expansion metathesis polymerization of a dendronized macromonomer
Cyclic organic nanostructures were prepared via ring-expansion metathesis polymerization of a dendronized norbornene macromonomer. The strategy provides a direct, efficient route to nanoscale rings in a single operation. AFM imaging confirmed toroidal features having diameters of ca. 35â40 nm
Ordered spectral statistics in 1D disordered supersymmetric quantum mechanics and Sinai diffusion with dilute absorbers
Some results on the ordered statistics of eigenvalues for one-dimensional
random Schr\"odinger Hamiltonians are reviewed. In the case of supersymmetric
quantum mechanics with disorder, the existence of low energy delocalized states
induces eigenvalue correlations and makes the ordered statistics problem
nontrivial. The resulting distributions are used to analyze the problem of
classical diffusion in a random force field (Sinai problem) in the presence of
weakly concentrated absorbers. It is shown that the slowly decaying averaged
return probability of the Sinai problem, \mean{P(x,t|x,0)}\sim \ln^{-2}t, is
converted into a power law decay, \mean{P(x,t|x,0)}\sim t^{-\sqrt{2\rho/g}},
where is the strength of the random force field and the density of
absorbers.Comment: 10 pages ; LaTeX ; 4 pdf figures ; Proceedings of the meeting
"Fundations and Applications of non-equilibrium statistical mechanics",
Nordita, Stockholm, october 2011 ; v2: appendix added ; v3: figure 2.left
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Assessment of multireference approaches to explicitly correlated full configuration interaction quantum Monte Carlo.
The Full Configuration Interaction Quantum Monte Carlo (FCIQMC) method has proved able to provide near-exact solutions to the electronic Schrödinger equation within a finite orbital basis set, without relying on an expansion about a reference state. However, a drawback to the approach is that being based on an expansion of Slater determinants, the FCIQMC method suffers from a basis set incompleteness error that decays very slowly with the size of the employed single particle basis. The FCIQMC results obtained in a small basis set can be improved significantly with explicitly correlated techniques. Here, we present a study that assesses and compares two contrasting "universal" explicitly correlated approaches that fit into the FCIQMC framework: the [2]R12 method of Kong and Valeev [J. Chem. Phys. 135, 214105 (2011)] and the explicitly correlated canonical transcorrelation approach of Yanai and Shiozaki [J. Chem. Phys. 136, 084107 (2012)]. The former is an a posteriori internally contracted perturbative approach, while the latter transforms the Hamiltonian prior to the FCIQMC simulation. These comparisons are made across the 55 molecules of the G1 standard set. We found that both methods consistently reduce the basis set incompleteness, for accurate atomization energies in small basis sets, reducing the error from 28 mEh to 3-4 mEh. While many of the conclusions hold in general for any combination of multireference approaches with these methodologies, we also consider FCIQMC-specific advantages of each approach.Royal Societ
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