pinecone/core-2020-05-10-deduplication huggingface dataset:
The function of endocytosis in Wnt signaling

This is the final version of the article. Available from Springer Verlag via the DOI in this record.Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.Funding was provided by Deutsche Forschungsgemeinschaft (Grant no. SCHO847-5) and the University of Exeter (GB) (LSI Start-up Grant)
Structural variations in wheat HKT1;5 underpin differences in Na+ transport capacity

An important trait associated with the salt tolerance of wheat is the exclusion of sodium ions ( Na⁺) from the shoot. We have previously shown that the sodium transporters TmHKT1;5-A and TaHKT1;5-D, from Triticum monoccocum (Tm) and Triticum aestivum (Ta), are encoded by genes underlying the major shoot Na⁺- exclusion loci Nax1 and Kna1, respectively. Here, using heterologous expression, we show that the affinity (Km) for the Na⁺ transport of TmHKT1;5-A, at 2.66 mM, is higher than that of TaHKT1;5-D at 7.50 mM. Through 3D structural modelling, we identify residues D⁴⁷¹/a gap and D⁴⁷⁴/ G⁴⁷³ that contribute to this property. We identify four additional mutations in amino acid residues that inhibit the transport activity of TmHKT1;5-A, which are predicted to be the result of an occlusion of the pore. We propose that the underlying transport properties of TmHKT1;5-A and TaHKT1;5-D contribute to their unique ability to improve Na⁺ exclusion in wheat that leads to an improved salinity tolerance in the field.Bo Xu, Shane Waters, Caitlin S. Byrt, Darren Plett, Stephen D. Tyerman, Mark Tester, Rana Munns, Maria Hrmova, Matthew Gilliha
Inhibitors of protein translocation across membranes of the secretory pathway: novel antimicrobial and anticancer agents

Proteins routed to the secretory pathway start their journey by being transported across biological membranes, such as the endoplasmic reticulum. The essential nature of this protein translocation process has led to the evolution of several factors that specifically target the translocon and block translocation. In this review, various translocation pathways are discussed together with known inhibitors of translocation. Properties of signal peptide-specific systems are highlighted for the development of new therapeutic and antimicrobial applications, as compounds can target signal peptides from either host cells or pathogens and thereby selectively prevent translocation of those specific proteins. Broad inhibition of translocation is also an interesting target for the development of new anticancer drugs because cancer cells heavily depend on efficient protein translocation into the endoplasmic reticulum to support their fast growth.status: publishe
Biochemistry of proinflammatory macrophage activation.

In the last decade, metabolism has been recognized as a major determinant of immunological processes. During an inflammatory response, macrophages undergo striking changes in their metabolism. This metabolic reprogramming is governed by a complex interplay between metabolic enzymes and metabolites of different pathways and represents the basis for proper macrophage function. It is now evident that these changes go far beyond the well-known Warburg effect and the perturbation of metabolic targets is being investigated as a means to treat infections and auto-immune diseases. In the present review, we will aim to provide an overview of the metabolic responses during proinflammatory macrophage activation and show how these changes modulate the immune response
Regulating the human HECT E3 ligases

Ubiquitination, the covalent attachment of ubiquitin to proteins, by E3 ligases of the HECT (homologous to E6AP C terminus) family is critical in controlling diverse physiological pathways. Stringent control of HECT E3 ligase activity and substrate specificity is essential for cellular health, whereas deregulation of HECT E3s plays a prominent role in disease. The cell employs a wide variety of regulatory mechanisms to control HECT E3 activity and substrate specificity. Here, we summarize the current understanding of these regulatory mechanisms that control HECT E3 function. Substrate specificity is generally determined by interactions of adaptor proteins with domains in the N-terminal extensions of HECT E3 ligases. These N-terminal domains have also been found to interact with the HECT domain, resulting in the formation of inhibitory conformations. In addition, catalytic activity of the HECT domain is commonly regulated at the level of E2 recruitment and through HECT E3 oligomerization. The previously mentioned regulatory mechanisms can be controlled through protein–protein interactions, post-translational modifications, the binding of calcium ions, and more. Functional activity is determined not only by substrate recruitment and catalytic activity, but also by the type of ubiquitin polymers catalyzed to the substrate. While this is often determined by the specific HECT member, recent studies demonstrate that HECT E3s can be modulated to alter the type of ubiquitin polymers they catalyze. Insight into these diverse regulatory mechanisms that control HECT E3 activity may open up new avenues for therapeutic strategies aimed at inhibition or enhancement of HECT E3 function in disease-related pathways
Memory corticalization triggered by?REM sleep: mechanisms of?cellular and?systems consolidation

Once viewed as a passive physiological state, sleep is a heterogeneous and complex sequence of brain states with essential efects on synaptic plasticity and neuronal functioning. Rapid-eye-movement (REM) sleep has been shown to promote calcium-dependent plasticity in principal neurons of the cerebral cortex, both during memory consolidation in adults and during post-natal development. This article reviews the plasticity mechanisms triggered by REM sleep, with a focus on the emerging role of kinases and immediate-early genes for the progressive corticalization of hippocampus-dependent memories. The body of evidence suggests that memory corticalization triggered by REM sleep is a systemic phenomenon with cellular and molecular causes
Pluripotent stem cell-derived cochlear cells: a challenge in constant progress

Hearing loss is a common affection mainly resulting from irreversible loss of the sensory hair cells of the cochlea; therefore, developing therapies to replace missing hair cells is essential. Understanding the mechanisms that drive their formation will not only help to unravel the molecular basis of deafness, but also give a roadmap for recapitulating hair cells development from cultured pluripotent stem cells. In this review, we provide an overview of the molecular mechanisms involved in hair cell production from both human and mouse embryonic stem cells. We then provide insights how this knowledge has been applied to differentiate induced pluripotent stem cells into otic progenitors and hair cells. Finally, we discuss the current limitations for properly obtaining functional hair cell in a Petri dish, as well as the difficulties that have to be overcome prior to consider stem cell therapy as a potential treatment for hearing loss.Peer reviewe
(Modified) Fredholm Determinants for Operators with Matrix-Valued
  Semi-Separable Integral Kernels Revisited

We revisit the computation of (2-modified) Fredholm determinants for
operators with matrix-valued semi-separable integral kernels. The latter occur,
for instance, in the form of Green's functions associated with closed ordinary
differential operators on arbitrary intervals on the real line. Our approach
determines the (2-modified) Fredholm determinants in terms of solutions of
closely associated Volterra integral equations, and as a result offers a
natural way to compute such determinants.
  We illustrate our approach by identifying classical objects such as the Jost
function for half-line Schr\"odinger operators and the inverse transmission
coefficient for Schr\"odinger operators on the real line as Fredholm
determinants, and rederiving the well-known expressions for them in due course.
We also apply our formalism to Floquet theory of Schr\"odinger operators, and
upon identifying the connection between the Floquet discriminant and underlying
Fredholm determinants, we derive new representations of the Floquet
discriminant.
  Finally, we rederive the explicit formula for the 2-modified Fredholm
determinant corresponding to a convolution integral operator, whose kernel is
associated with a symbol given by a rational function, in a straghtforward
manner. This determinant formula represents a Wiener-Hopf analog of Day's
formula for the determinant associated with finite Toeplitz matrices generated
by the Laurent expansion of a rational function.Comment: LaTeX, 37 page
Characteristic Functions for Ergodic Tuples

Gohm, Rolf; Dey, S., 'Characteristic function for ergodic tuples', Integral Equations and Operator Theory 58(1) pp.43-63 RAE2008Motivated by a result on weak Markov dilations, we define a notion of characteristic function for ergodic and coisometric row contractions with a one-dimensional invariant subspace for the adjoints. This extends a definition given by G. Popescu. We prove that our characteristic function is a complete unitary invariant for such tuples and show how it can be computed.preprintpreprintPeer reviewe
Some new observations on interpolation in the spectral unit ball

We present several results associated to a holomorphic-interpolation problem
for the spectral unit ball \Omega_n, n\geq 2. We begin by showing that a known
necessary condition for the existence of a
$\mathcal{O}(D;\Omega_n)$-interpolant (D here being the unit disc in the
complex plane), given that the matricial data are non-derogatory, is not
sufficient. We provide next a new necessary condition for the solvability of
the two-point interpolation problem -- one which is not restricted only to
non-derogatory data, and which incorporates the Jordan structure of the
prescribed data. We then use some of the ideas used in deducing the latter
result to prove a Schwarz-type lemma for holomorphic self-maps of \Omega_n,
n\geq 2.Comment: Added a definition (Def.1.1); 2 of the 4 results herein are minor
  refinements of those in the author's preprint math.CV/0608177; to appear in
  Integral Eqns. Operator Theor
The local form of doubly stochastic maps and joint majorization in II1 factors

We find a description of the restriction of doubly stochastic maps to separable abelian C ∗ -subalgebras of a II1 factor M. We use this local form of doubly stochastic maps to develop a notion of joint majorization between ntuples of mutually commuting self-adjoint operators that extends those of Kamei (for single self-adjoint operators) and Hiai (for single normal operators) in the II1 factor case. Several characterizations of this joint majorization are obtained. As a byproduct we prove that any separable abelian C ∗ -subalgebra of M can be embedded into a separable abelian C ∗ -subalgebra of M with diffuse spectral measure.Fil: Argerami, Martin. University of Regina; CanadáFil: Massey, Pedro Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Matematicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderon; Argentin
Resolvent estimates for operators belonging to exponential classes

For $a,\alpha>0$ let $E(a,\alpha)$ be the set of all compact operators $A$ on
a separable Hilbert space such that $s_n(A)=O(\exp(-an^\alpha))$, where
$s_n(A)$ denotes the $n$-th singular number of $A$. We provide upper bounds for
the norm of the resolvent $(zI-A)^{-1}$ of $A$ in terms of a quantity
describing the departure from normality of $A$ and the distance of $z$ to the
spectrum of $A$. As a consequence we obtain upper bounds for the Hausdorff
distance of the spectra of two operators in $E(a,\alpha)$.Comment: AMS-LaTeX, 20 page
PT-symmetric waveguides

We introduce a planar waveguide of constant width with non-Hermitian
PT-symmetric Robin boundary conditions. We study the spectrum of this system in
the regime when the boundary coupling function is a compactly supported
perturbation of a homogeneous coupling. We prove that the essential spectrum is
positive and independent of such perturbation, and that the residual spectrum
is empty. Assuming that the perturbation is small in the supremum norm, we show
that it gives rise to real weakly-coupled eigenvalues converging to the
threshold of the essential spectrum. We derive sufficient conditions for these
eigenvalues to exist or to be absent. Moreover, we construct the leading terms
of the asymptotic expansions of these eigenvalues and the associated
eigenfunctions.Comment: LaTeX, 25 pages; more detailed description of various types of
  spectra; version accepted for publication in Integral Equations Operator
  Theor
Duality, Tangential Interpolation, and Toeplitz Corona Problems

In this paper we extend a method of Arveson and McCullough to prove a
tangential interpolation theorem for subalgebras of $H^\infty$. This tangential
interpolation result implies a Toelitz corona theorem. In particular, it is
shown that the set of matrix positivity conditions is indexed by cyclic
subspaces, which is analogous to the results obtained for the ball and the
polydisk algebra by Trent-Wick and Douglas-Sarkar.Comment: 17 pages, no figures, to appear in Integral Equations and Operator
  Theor
Multipliers for p-Bessel sequences in Banach spaces

Multipliers have been recently introduced as operators for Bessel sequences
and frames in Hilbert spaces. These operators are defined by a fixed
multiplication pattern (the symbol) which is inserted between the analysis and
synthesis operators. In this paper, we will generalize the concept of Bessel
multipliers for p-Bessel and p-Riesz sequences in Banach spaces. It will be
shown that bounded symbols lead to bounded operators. Symbols converging to
zero induce compact operators. Furthermore, we will give sufficient conditions
for multipliers to be nuclear operators. Finally, we will show the continuous
dependency of the multipliers on their parameters.Comment: 17 page
$L^p$-approximation of the integrated density of states for
  Schr\"odinger operators with finite local complexity

We study spectral properties of Schr\"odinger operators on $\RR^d$. The
electromagnetic potential is assumed to be determined locally by a colouring of
the lattice points in $\ZZ^d$, with the property that frequencies of finite
patterns are well defined. We prove that the integrated density of states
(spectral distribution function) is approximated by its finite volume
analogues, i.e.the normalised eigenvalue counting functions. The convergence
holds in the space $L^p(I)$ where $I$ is any finite energy interval and $1\leq
p< \infty$ is arbitrary.Comment: 15 pages; v2 has minor fixe
Remarks on the Trotter-Kato Product Formula for Unitary Groups

International audienceLet A and B be non-negative self-adjoint operators in a separable Hilbert space such that their form sum C is densely defined. It is shown that the Trotter product formula holds for imaginary parameter values in the L 2-norm, that is, one has limn→+∞∫−TT∥∥(e−itA/ne−itB/n)nh−e−itCh∥∥2dt=0 for each element h of the Hilbert space and any T > 0. This result is extended to the class of holomorphic Kato functions, to which the exponential function belongs. Moreover, for a class of admissible functions: ϕ(⋅),ψ(⋅):R+⟶C , where R+:=[0,∞) , satisfying in addition Re(ϕ(y))≥0,Jm(ϕ(y)≤0 and Jm(ψ(y))≤0 for y∈R+ , we prove that \rm s-limn→∞(ϕ(tA/n)ψ(tB/n))n=e−itC holds true uniformly on [0,T]∋t for any T > 0
Essential self-adjointness of magnetic Schr\"odinger operators on
  locally finite graphs

We give sufficient conditions for essential self-adjointness of magnetic
Schr\"odinger operators on locally finite graphs. Two of the main theorems of
the present paper generalize recent results of Torki-Hamza.Comment: 14 pages; The present version differs from the original version as
  follows: the ordering of presentation has been modified in several places,
  more details have been provided in several places, some notations have been
  changed, two examples have been added, and several new references have been
  inserted. The final version of this preprint will appear in Integral
  Equations and Operator Theor
Resolvent expansions on hybrid manifolds

We study Laplace-type operators on hybrid manifolds, i.e. on configurations
consisting of closed two-dimensional manifolds and one-dimensional segments.
Such an operator can be constructed by using the Laplace-Beltrami operators on
each component with some boundary conditions at the points of gluing. The large
spectral parameter expansion of the trace of the second power of the resolvent
is obtained. Some questions of the inverse spectral theory are adressed.Comment: To appear in Integral Equations and Operator Theory (2011
Denjoy-Carleman differentiable perturbation of polynomials and unbounded
  operators

Let $t\mapsto A(t)$ for $t\in T$ be a $C^M$-mapping with values unbounded
operators with compact resolvents and common domain of definition which are
self-adjoint or normal. Here $C^M$ stands for $C^\om$ (real analytic), a
quasianalytic or non-quasianalytic Denjoy-Carleman class, $C^\infty$, or a
H\"older continuity class $C^{0,\al}$. The parameter domain $T$ is either
$\mathbb R$ or $\mathbb R^n$ or an infinite dimensional convenient vector
space. We prove and review results on $C^M$-dependence on $t$ of the
eigenvalues and eigenvectors of $A(t)$.Comment: 8 page
Shape derivatives of boundary integral operators in electromagnetic scattering. Part I: Shape differentiability of pseudo-homogeneous boundary integral operators.

International audienceIn this paper we study the shape differentiability properties of a class of boundary integral operators and of potentials with weakly singular pseudo-homogeneous kernels acting between classical Sobolev spaces, with respect to smooth deformations of the boundary. We prove that the boundary integral operators are infinitely differentiable without loss of regularity. The potential operators are infinitely shape differentiable away from the boundary, whereas their derivatives lose regularity near the boundary. We study the shape differentiability of surface differential operators. The shape differentiability properties of the usual strongly singular or hypersingular boundary integral operators of interest in acoustic, elastodynamic or electromagnetic potential theory can then be established by expressing them in terms of integral operators with weakly singular kernels and of surface differential operators
Shape derivatives of boundary integral operators in electromagnetic scattering. Part II : Application to scattering by a homogeneous dielectric obstacle

International audienceWe develop the shape derivative analysis of solutions to the problem of scattering of time-harmonic electromagnetic waves by a bounded penetrable obstacle. Since boundary integral equations are a classical tool to solve electromagnetic scattering problems, we study the shape differentiability properties of the standard electromagnetic boundary integral operators. The latter are typically bounded on the space of tangential vector fields of mixed regularity $TH\sp{-\frac{1}{2}}(\Div_{\Gamma},\Gamma)$. Using Helmholtz decomposition, we can base their analysis on the study of pseudo-differential integral operators in standard Sobolev spaces, but we then have to study the Gâteaux differentiability of surface differential operators. We prove that the electromagnetic boundary integral operators are infinitely differentiable without loss of regularity. We also give a characterization of the first shape derivative of the solution of the dielectric scattering problem as a solution of a new electromagnetic scattering problem
Fredholm integral equations of the first kind and topological
  information theory

The Fredholm integral equations of the first kind are a classical example of
ill-posed problem in the sense of Hadamard. If the integral operator is
self-adjoint and admits a set of eigenfunctions, then a formal solution can be
written in terms of eigenfunction expansions. One of the possible methods of
regularization consists in truncating this formal expansion after restricting
the class of admissible solutions through a-priori global bounds. In this paper
we reconsider various possible methods of truncation from the viewpoint of the
$\varepsilon$-coverings of compact sets.Comment: 17 page
Dilations of some VH-spaces operator valued invariant kernels

Cataloged from PDF version of article.We investigate VH-spaces (Vector Hilbert spaces, or Loynes spaces) operator valued Hermitian kernels that are invariant under actions of *-semigroups from the point of view of generation of *-representations, linearizations (Kolmogorov decompositions), and reproducing kernel spaces. We obtain a general dilation theorem in both Kolmogorov and reproducing kernel space representations, that unifies many dilation results, in particular B. Sz.-Nagy's and Stinesprings' dilation type theorems. © 2012 Springer Basel
Optimization of quasi-normal eigenvalues for Krein-Nudelman strings

The paper is devoted to optimization of resonances for Krein strings with
total mass and statical moment constraints. The problem is to design for a
given $\alpha \in \R$ a string that has a resonance on the line $\alpha + \i
\R$ with a minimal possible modulus of the imaginary part. We find optimal
resonances and strings explicitly.Comment: 9 pages, these results were extracted in a slightly modified form
  from the earlier e-print arXiv:1103.4117 [math.SP] following an advise of a
  journal's refere
1D Schr\"{o}dinger operators with short range interactions: two-scale
  regularization of distributional potentials

For real bounded functions \Phi and \Psi of compact support, we prove the
norm resolvent convergence, as \epsilon and \nu tend to 0, of a family of
one-dimensional Schroedinger operators on the line of the form S_{\epsilon,
\nu}=
-D^2+\alpha\epsilon^{-2}\Phi(\epsilon^{-1}x)+\beta\nu^{-1}\Psi(\nu^{-1}x),
provided the ratio \nu/\epsilon has a finite or infinity limit. The limit
operator S_0 depends on the shape of \Phi and \Psi as well as on the limit of
ratio \nu/\epsilon. If the potential \alpha\Phi possesses a zero-energy
resonance, then S_0 describes a non trivial point interaction at the origin.
Otherwise S_0 is the direct sum of the Dirichlet half-line Schroedinger
operators.Comment: 20 pages, minor correction