bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ondelettes, analyses multirésolutions et filtres miroirs en quadrature
Authors: Cohen A. 
Published: February 2017

In this paper, we give a complete characterisation of the “quadrature mirror filters” associated with a multiscale analysis. As an application, new types of wavelet belonging to Schwartz class are constructed.

Résumé

Suivant un raisonnement dû à S. Mallat, on peut reconstituer une analyse multirésolution de

L^2(ℝ^n)

par la donnée simple d’une fonction

m_0

possédant la propriété de « quadrature mirror filter ». Nous proposons ici une condition nécessaire et suffisante portant sur cette fonction pour qu’elle engendre effectivement une analyse multirésolution. Des applications sont ensuite présentées pour illustrer le sens de ce critère. Ainsi, dans le cas unidimensionel, nous construisons une base orthonormée d’ondelettes de la classe de Schwartz dont les éléments sont arbitrairement proches d’un signal progressif. Dans le cas multidimensionel, nous presentons une généralisation non triviale de cette construction.
Multiple critical points for variational problems on partially ordered Hilbert spaces
Authors: Wysocki K. 
Published: February 2017

We are studying the existence of multiple critical points for functionals whose potential operators preserve an order structure. By using Morse type arguments we prove that the existence of local minima of a functional

Φ

which are ordered in a special way « forces »

Φ

to have many additional critical points. We also show how these abstract results apply to a concrete situation.

Résumé

Nous étudions l’existence de points critiques multiples pour les problèmes variationnels dont les opérateurs potentiels préservent une structure d’ordre en utilisant des arguments du type Morse. Nous démontrons que, pour une fonctionnelle

Φ

, l’existence de minima locaux qui soient ordonnés d’une manière particulière « force »

Φ

à avoir beaucoup d’autres points critiques. Nous montrons comment ces résultats abstraits s’appliquent à une situation concrète.
Some inverse mapping theorems
Authors: Frankowska Hélène 
Published: February 2017

We prove several first and high order inverse mapping theorems for set-valued maps from a complete metric space to a Banach space and study the stability of the open mapping principle. The obtained results allow to investigate questions of controllability of finite and infinite dimensional control systems, necessary conditions for optimality, implicit function theorem, stability of constraints with respect to a parameter. Applications to problems of optimization, control theory and nonsmooth analysis are provided.

Résumé
On démontre des théorèmes d’inversion locale d’ordre quelconque pour des correspondances définies sur un espace métrique complet. Les résultats sont appliqués à quelques problèmes des contrôles.
Stable approximations of set-valued maps
Authors: Aubin Jean-Pierre , Wets Roger J.B. 
Published: February 2017

The celebrated Lax’ principle “stability and consistency implies convergence” is adapted to the case of nonlinear equation and even inclusions (multivalued equations) through a convenient concept of stability. It requires the definition of “contingent derivative” of single or set-valued maps and states that a family of maps is stable if and only if the inverses of their contingent derivatives are bounded.
An extension of the Banach-Steinhauss theorem to the set-valued analogues of continuous linear operators is also provided, as well as relations between pointwise and graph convergence of sequences of set-valued maps.

Résumé
Le célèbre principe de Lax: « stabilité et consistence impliquent convergence » est adapté au cas des équations non linéaires et même des inclusions (équations multivoques) grâce à une définition adéquate de la stabilité. Celle-ci est basée sur le concept de « dérivée contingente » d’une correspondance. On dit qu’une famille de correspondances est stable si les inverses de leurs dérivées contingentes sont bornés.
On démontre aussi une adaptation du théorème de Banach-Steinhauss au cas des processus convexes fermés, qui sont les analogues multivoques des opérateurs linéaires continus, et on examine les relations entre convergence simple et convergence graphique d’une suite de correspondances.
Convergence of convex-concave saddle functions: applications to convex programming and mechanics
Authors: Wets Roger J.-B. , Azé Dominique , Attouch Hedy 
Published: February 2017

It is shown that operation of partial conjugation (the partial Legendre-Fenchel transform) of bivariate convex-concave functions has bicontinuity properties with respect to the extended epi/hypo-convergence of saddle functions and the epi-convergence of the partial conjugate (convex) functions. The results are applied to study the stability of the optimal solutions and associated multipliers of convex programs, and to a couple of problems in mechanics.

Résumé
On montre que la conjuguée partielle (la transformation de Legendre-Fenchel partielle) de fonctions de selles convexes-concaves a des propriétés de bicontinuité par rapport à l’épi/hypo-convergence des fonctions de selles et l’épi-convergence des conjuguées partielles. On applique les résultats à l’étude de la stabilité des solutions et des multiplicateurs (de Lagrange associés à ces solutions) de problèmes d’optimisation convexe, ainsi qu’à des problèmes en mécanique qui proviennent de l’homogénéisation et du renforoement de matériaux.
Differential inclusions with free time
Authors: Loewen Philip D. , Clarke Frank H. , Vinter Richard B. 
Published: February 2017

We prove Hamiltonian necessary conditions for stateconstrained differential inclusion problems in which the basic time interval is one of the unknowns. Previous approaches typically reduce this problem to one based on a fixed time interval by transforming the time variable into an auxiliary state – a device which unfortunately requires that the data exhibit rather smooth

t

-dependence. Here we use proximal analysis to avoid this transformation, and offer the first complete treatment of free-time problems whose dynamics are assumed to be merely measurable in

t

.

Résumé

Nous démontrons des conditions nécessaires d’optimalité sous forme hamiltonienne pour des problèmes de contrôle avec contraintes sur l’état lorsque l’horizon fait partie des inconnues. Notre étude utilise l’analyse proximale et s’applique des situations où la dépendance en

t

est simplement mesurable.
Long Term Effects of Early School Entry
Authors: de Lemos Marion M. 
Published: February 2017

The debate regarding age of entry to school goes back a number of years. It seemed to come to a head in the late 1970s, coinciding with the visit to Australia of Dr Raymond Moore, who put forward the somewhat extreme view that children should not start school before the age of about 8 to 10 years. Hisargument was based on a maturational view of development. Experiences must wait until the child is ‘ready’ and the brain has ‘matured’. In particular, he argued that exposure to early reading and the close work involved in the pre-school and early primary school could harm the developing visual system and lead to long-term visual defects, particularly short-sightedness.Moore's position was of course contrary to the mainstream of thought in this area, and particularly the recognition, stemming from the work of Hebb and Piaget, of the importance of the early environment in laying the foundations for later development. It nevertheless had some popular appeal, and was taken up by various parent and teacher pressure groups who called for changes to school entry policies and specifically raising the age of entry to school to five years.
The emerging role of RNAs in DNA damage repair
Authors: Hawley Ben R , Lu Wei-Ting , Wilczynska Ania , Bushell Martin 
Published: February 2017

Abstract
Many surveillance and repair mechanisms exist to maintain the integrity of our genome. All of the pathways described to date are controlled exclusively by proteins, which through their enzymatic activities identify breaks, propagate the damage signal, recruit further protein factors and ultimately resolve the break with little to no loss of genetic information. RNA is known to have an integral role in many cellular pathways, but, until very recently, was not considered to take part in the DNA repair process. Several reports demonstrated a conserved critical role for RNA-processing enzymes and RNA molecules in DNA repair, but the biogenesis of these damage-related RNAs and their mechanisms of action remain unknown. We will explore how these new findings challenge the idea of proteins being the sole participants in the response to DNA damage and reveal a new and exciting aspect of both DNA repair and RNA biology.
Genomic changes associated with the evolutionary transition of an insect gut symbiont into a blood-borne pathogen
Authors: Segers Francisca H I D , Kešnerová Lucie , Kosoy Michael , Engel Philipp 
Published: February 2017

Abstract
The genus Bartonella comprises facultative intracellular bacteria with a unique lifestyle. After transmission by blood-sucking arthropods they colonize the erythrocytes of mammalian hosts causing acute and chronic infectious diseases. Although the pathogen–host interaction is well understood, little is known about the evolutionary origin of the infection strategy manifested by Bartonella species. Here we analyzed six genomes of Bartonella apis, a honey bee gut symbiont that to date represents the closest relative of pathogenic Bartonella species. Comparative genomics revealed that B. apis encodes a large set of vertically inherited genes for amino acid and cofactor biosynthesis and nitrogen metabolism. Most pathogenic bartonellae have lost these ancestral functions, but acquired specific virulence factors and expanded a vertically inherited gene family for harvesting cofactors from the blood. However, the deeply rooted pathogen Bartonella tamiae has retained many of the ancestral genome characteristics reflecting an evolutionary intermediate state toward a host-restricted intraerythrocytic lifestyle. Our findings suggest that the ancestor of the pathogen Bartonella was a gut symbiont of insects and that the adaptation to blood-feeding insects facilitated colonization of the mammalian bloodstream. This study highlights the importance of comparative genomics among pathogens and non-pathogenic relatives to understand disease emergence within an evolutionary-ecological framework.
Spectroelectrochemical analysis of the mechanism of (photo)electrochemical hydrogen evolution at a catalytic interface
Authors: Pastor Ernest , Le Formal Florian , Mayer Matthew T. , Tilley S. David , Francàs Laia , Mesa Camilo A. , Grätzel Michael , Durrant James R. 
Published: February 2017

AbstractMulti-electron heterogeneous catalysis is a pivotal element in the (photo)electrochemical generation of solar fuels. However, mechanistic studies of these systems are difficult to elucidate by means of electrochemical methods alone. Here we report a spectroelectrochemical analysis of hydrogen evolution on ruthenium oxide employed as an electrocatalyst and as part of a cuprous oxide-based photocathode. We use optical absorbance spectroscopy to quantify the densities of reduced ruthenium oxide species, and correlate these with current densities resulting from proton reduction. This enables us to compare directly the catalytic function of dark and light electrodes. We find that hydrogen evolution is second order in the density of active, doubly reduced species independent of whether these are generated by applied potential or light irradiation. Our observation of a second order rate law allows us to distinguish between the most common reaction paths and propose a mechanism involving the homolytic reductive elimination of hydrogen.
Mutualism supports biodiversity when the direct competition is weak
Authors: Pascual-García Alberto , Bastolla Ugo 
Published: February 2017

AbstractA key question of theoretical ecology is which properties of ecosystems favour their stability and help maintaining biodiversity. This question recently reconsidered mutualistic systems, generating intense controversy about the role of mutualistic interactions and their network architecture. Here we show analytically and verify with simulations that reducing the effective interspecific competition and the propagation of perturbations positively influences structural stability against environmental perturbations, enhancing persistence. Noteworthy, mutualism reduces the effective interspecific competition only when the direct interspecific competition is weaker than a critical value. This critical competition is in almost all cases larger in pollinator networks than in random networks with the same connectance. Highly connected mutualistic networks reduce the propagation of environmental perturbations, a mechanism reminiscent of MacArthur’s proposal that ecosystem complexity enhances stability. Our analytic framework rationalizes previous contradictory results, and it gives valuable insight on the complex relationship between mutualism and biodiversity.
PEGylated graphene oxide elicits strong immunological responses despite surface passivation
Authors: Luo Nana , Weber Jeffrey K. , Wang Shuang , Luan Binquan , Yue Hua , Xi Xiaobo , Du Jing , Yang Zaixing , Wei Wei , Zhou Ruhong , Ma Guanghui 
Published: February 2017

AbstractEngineered nanomaterials promise to transform medicine at the bio–nano interface. However, it is important to elucidate how synthetic nanomaterials interact with critical biological systems before such products can be safely utilized in humans. Past evidence suggests that polyethylene glycol-functionalized (PEGylated) nanomaterials are largely biocompatible and elicit less dramatic immune responses than their pristine counterparts. We here report results that contradict these findings. We find that PEGylated graphene oxide nanosheets (nGO-PEGs) stimulate potent cytokine responses in peritoneal macrophages, despite not being internalized. Atomistic molecular dynamics simulations support a mechanism by which nGO-PEGs preferentially adsorb onto and/or partially insert into cell membranes, thereby amplifying interactions with stimulatory surface receptors. Further experiments demonstrate that nGO-PEG indeed provokes cytokine secretion by enhancing integrin β8-related signalling pathways. The present results inform that surface passivation does not always prevent immunological reactions to 2D nanomaterials but also suggest applications for PEGylated nanomaterials wherein immune stimulation is desired.
RD26 mediates crosstalk between drought and brassinosteroid signalling pathways
Authors: Ye Huaxun , Liu Sanzhen , Tang Buyun , Chen Jiani , Xie Zhouli , Nolan Trevor M. , Jiang Hao , Guo Hongqing , Lin Hung-Ying , Li Lei , Wang Yanqun , Tong Hongning , Zhang Mingcai , Chu Chengcai , Li Zhaohu , Aluru Maneesha , Aluru Srinivas , Schnable Patrick S. , Yin Yanhai 
Published: February 2017

AbstractBrassinosteroids (BRs) regulate plant growth and stress responses via the BES1/BZR1 family of transcription factors, which regulate the expression of thousands of downstream genes. BRs are involved in the response to drought, however the mechanistic understanding of interactions between BR signalling and drought response remains to be established. Here we show that transcription factor RD26 mediates crosstalk between drought and BR signalling. When overexpressed, BES1 target geneRD26can inhibit BR-regulated growth. Global gene expression studies suggest that RD26 can act antagonistically to BR to regulate the expression of a subset of BES1-regulated genes, thereby inhibiting BR function. We show that RD26 can interact with BES1 protein and antagonize BES1 transcriptional activity on BR-regulated genes and that BR signalling can also repress expression ofRD26and its homologues and inhibit drought responses. Our results thus reveal a mechanism coordinating plant growth and drought tolerance.
The role of alternative polyadenylation in the antiviral innate immune response
Authors: Jia Xin , Yuan Shaochun , Wang Yao , Fu Yonggui , Ge Yong , Ge Yutong , Lan Xihong , Feng Yuchao , Qiu Feifei , Li Peiyi , Chen Shangwu , Xu Anlong 
Published: February 2017

AbstractAlternative polyadenylation (APA) is an important regulatory mechanism of gene functions in many biological processes. However, the extent of 3′ UTR variation and the function of APA during the innate antiviral immune response are unclear. Here, we show genome-wide poly(A) sites switch and average 3′ UTR length shortens gradually in response to vesicular stomatitis virus (VSV) infection in macrophages. Genes with APA and mRNA abundance change are enriched in immune-related categories such as the Toll-like receptor, RIG-I-like receptor, JAK-STAT and apoptosis-related signalling pathways. The expression of 3′ processing factors is down-regulated upon VSV infection. When the core 3′ processing factors are knocked down, viral replication is affected. Thus, our study reports the annotation of genes with APA in antiviral immunity and highlights the roles of 3′ processing factors on 3′ UTR variation upon viral infection.
Direct experimental determination of the topological winding number of skyrmions in Cu2OSeO3
Authors: Zhang S. L. , van der Laan G. , Hesjedal T. 
Published: February 2017

AbstractThe mathematical concept of topology has brought about significant advantages that allow for a fundamental understanding of the underlying physics of a system. In magnetism, the topology of spin order manifests itself in the topological winding number which plays a pivotal role for the determination of the emergent properties of a system. However, the direct experimental determination of the topological winding number of a magnetically ordered system remains elusive. Here, we present a direct relationship between the topological winding number of the spin texture and the polarized resonant X-ray scattering process. This relationship provides a one-to-one correspondence between the measured scattering signal and the winding number. We demonstrate that the exact topological quantities of the skyrmion material Cu2OSeO3 can be directly experimentally determined this way. This technique has the potential to be applicable to a wide range of materials, allowing for a direct determination of their topological properties.
Human brain metastatic stroma attracts breast cancer cells via chemokines CXCL16 and CXCL12
Authors: Chung Brile , Esmaeili Ali A. , Gopalakrishna-Pillai Sailesh , Murad John P. , Andersen Emily S. , Kumar Reddy Naveen , Srinivasan Gayathri , Armstrong Brian , Chu Caleb , Kim Young , Tong Tommy , Waisman James , Yim John H. , Badie Behnam , Lee Peter P. 
Published: February 2017

AbstractThe tumor microenvironment is composed of heterogeneous populations of cells, including cancer, immune, and stromal cells. Progression of tumor growth and initiation of metastasis is critically dependent on the reciprocal interactions between cancer cells and stroma. Through RNA-Seq and protein analyses, we found that cancer-associated fibroblasts derived from human breast cancer brain metastasis express significantly higher levels of chemokines CXCL12 and CXCL16 than fibroblasts from primary breast tumors or normal breast. To further understand the interplay between cancer cells and cancer-associated fibroblasts from each site, we developed three-dimensional organoids composed of patient-derived primary or brain metastasis cancer cells with matching cancer-associated fibroblasts. Three-dimensional CAF aggregates generated from brain metastasis promote migration of cancer cells more effectively than cancer-associated fibroblast aggregates derived from primary tumor or normal breast stromal cells. Treatment with a CXCR4 antagonist and/or CXCL16 neutralizing antibody, alone or in combination, significantly inhibited migration of cancer cells to brain metastatic cancer-associated fibroblast aggregates. These results demonstrate that human brain metastasis cancer-associated fibroblasts potently attract breast cancer cells via chemokines CXCL12 and CXCL16, and blocking CXCR6-CXCL16/CXCR4-CXCL12 receptor–ligand interactions may be an effective therapy for preventing breast cancer brain metastasis.
Experimental quantum forgery of quantum optical money
Authors: Bartkiewicz Karol , Černoch Antonín , Chimczak Grzegorz , Lemr Karel , Miranowicz Adam , Nori Franco 
Published: February 2017

AbstractUnknown quantum information cannot be perfectly copied (cloned). This statement is the bedrock of quantum technologies and quantum cryptography, including the seminal scheme of Wiesner’s quantum money, which was the first quantum-cryptographic proposal. Surprisingly, to our knowledge, quantum money has not been tested experimentally yet. Here, we experimentally revisit the Wiesner idea, assuming a banknote to be an image encoded in the polarization states of single photons. We demonstrate that it is possible to use quantum states to prepare a banknote that cannot be ideally copied without making the owner aware of only unauthorized actions. We provide the security conditions for quantum money by investigating the physically-achievable limits on the fidelity of 1-to-2 copying of arbitrary sequences of qubits. These results can be applied as a security measure in quantum digital right management.
Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain
Authors: Liu Yuan-Chun , Zhang Fu-Chun , Rice Thomas Maurice , Wang Qiang-Hua 
Published: February 2017

AbstractSr2RuO4 is a leading candidate for chiral p-wave superconductivity. The detailed mechanism of superconductivity in this material is still the subject of intense investigations. Since superconductivity is sensitive to the topology of the Fermi surface (the contour of zero-energy quasi-particle excitations in the momentum space in the normal state), changing this topology can provide a strong test of theory. Recent experiments tuned the Fermi surface topology efficiently by applying planar anisotropic strain. Using functional renormalization group theory, we study the superconductivity and competing orders in Sr2RuO4 under strain. We find a rapid initial increase in the superconducting transition temperature T
c
, which can be associated with the evolution of the Fermi surface toward a Lifshitz reconstruction under increasing strain. Before the Lifshitz reconstruction is reached, however, the system switches from the superconducting state to a spin density wave state. The theory agrees well with recent strain experiments showing an enhancement of T
c
followed by an intriguing sudden drop.