Guglielmi, Michel; Johannesen, Hl
, Essex, Hertfordshire, Norfolk and Suffolk. Research found that there was a lack of identity or sense of belonging and nothing anchoring people to the region as a whole. Common affinity is somehow forced to the people of East England and thereby we came to the conclusion that a single landmark or a...... a sense of belonging to people sharing deterritorialized synchronic experiences. But at the same time, the immersion experience is highly low tech and desperately analog, mainly based on fabulation, cartoons, and mushrooms growing in local forests. It ultimately appeals to the experienced sense of...
J. Navarro; Sancho, C.; Sancho, P.
2009-01-01
A functor of sets $\\mathbb X$ over the category of $K$-commutative algebras is said to be an affine functor if its functor of functions, $\\mathbb A_{\\mathbb X}$, is reflexive and $\\mathbb X=\\Spec \\mathbb A_{\\mathbb X}$. We prove that affine functors are equal to a direct limit of affine schemes and that affine schemes, formal schemes, the completion of affine schemes along a closed subscheme, etc., are affine functors. Endowing an affine functor $\\mathbb X$ with a functor of monoids structure...
Meyer, Mathieu; Schuett, Carsten; Werner, Elisabeth M.
2013-01-01
An affine invariant point on the class of convex bodies in R^n, endowed with the Hausdorff metric, is a continuous map p which is invariant under one-to-one affine transformations A on R^n, that is, p(A(K))=A(p(K)). We define here the new notion of dual affine point q of an affine invariant point p by the formula q(K^{p(K)})=p(K) for every convex body K, where K^{p(K)} denotes the polar of K with respect to p(K). We investigate which affine invariant points do have a dual point, whether this ...
Høholdt, Tom; Beelen, Peter; Ghorpade, Sudhir Ramakant
2010-01-01
We consider a new class of linear codes, called affine Grassmann codes. These can be viewed as a variant of generalized Reed-Muller codes and are closely related to Grassmann codes.We determine the length, dimension, and the minimum distance of any affine Grassmann code. Moreover, we show that...... affine Grassmann codes have a large automorphism group and determine the number of minimum weight codewords....
Affine and Projective Geometry
Bennett, M K
1995-01-01
An important new perspective on AFFINE AND PROJECTIVE GEOMETRY. This innovative book treats math majors and math education students to a fresh look at affine and projective geometry from algebraic, synthetic, and lattice theoretic points of view. Affine and Projective Geometry comes complete with ninety illustrations, and numerous examples and exercises, covering material for two semesters of upper-level undergraduate mathematics. The first part of the book deals with the correlation between synthetic geometry and linear algebra. In the second part, geometry is used to introduce lattice theory
Gueltekin, Kemal [Izmir Institute of Technology, Department of Physics, Izmir (Turkey)
2016-03-15
In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on the determinants of the Ricci tensor, the torsion tensor, the Riemann tensor, and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to the construction of the affine connection in terms of the curvature and torsion tensors. Our solutions of the dynamical equations show that the curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor. (orig.)
Affine and degenerate affine BMW algebras: Actions on tensor space
Daugherty, Zajj; Virk, Rahbar
2012-01-01
The affine and degenerate affine Birman-Murakami-Wenzl (BMW) algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic quantum groups and Lie algebras, respectively. Cyclotomic BMW algebras, affine and cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper we explain how the affine and degenerate affine BMW algebras are tantalizers (tensor power centralizer algebras) by defining actions of the affine braid group and the degenerate affine braid algebra on tensor space and showing that, in important cases, these actions induce actions of the affine and degenerate affine BMW algebras. We then exploit the connection to quantum groups and Lie algebras to determine universal parameters for the affine and degenerate affine BMW algebras. Finally, we show that the universal parameters are central elements--the higher Casimir elements for orthogonal and symplectic enveloping algebras and quantum groups.
Skjødt, Mette Louise
Yeast surface display is an effective tool for antibody affinity maturation because yeast can be used as an all-in-one workhorse to assemble, display and screen diversified antibody libraries. By employing the natural ability of yeast Saccharomyces cerevisiae to efficiently recombine multiple DNA...
Affine and degenerate affine BMW algebras: The center
Daugherty, Zajj; Virk, Rahbar
2011-01-01
The degenerate affine and affine BMW algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic Lie algebras and quantum groups, respectively. Cyclotomic BMW algebras, affine Hecke algebras, cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper the theory is unified by treating the orthogonal and symplectic cases simultaneously; we make an exact parallel between the degenerate affine and affine cases via a new algebra which takes the role of the affine braid group for the degenerate setting. A main result of this paper is an identification of the centers of the affine and degenerate affine BMW algebras in terms of rings of symmetric functions which satisfy a "cancellation property" or "wheel condition" (in the degenerate case, a reformulation of a result of Nazarov). Miraculously, these same rings also arise in Schubert calculus, as the cohomology and K-theory of isotropic Grassmanians and symplectic loop Grassmanians. We also establish new inte...
Hierarchical Affinity Propagation
Givoni, Inmar; Frey, Brendan J
2012-01-01
Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...
Affinity driven social networks
Ruyú, B.; Kuperman, M. N.
2007-04-01
In this work we present a model for evolving networks, where the driven force is related to the social affinity between individuals of a population. In the model, a set of individuals initially arranged on a regular ordered network and thus linked with their closest neighbors are allowed to rearrange their connections according to a dynamics closely related to that of the stable marriage problem. We show that the behavior of some topological properties of the resulting networks follows a non trivial pattern.
Affine General Equilibrium Models
Bjørn Eraker
2008-01-01
No-arbitrage models are extremely flexible modelling tools but often lack economic motivation. This paper describes an equilibrium consumption-based CAPM framework based on Epstein-Zin preferences, which produces analytic pricing formulas for stocks and bonds under the assumption that macro growth rates follow affine processes. This allows the construction of equilibrium pricing formulas while maintaining the same flexibility of state dynamics as in no-arbitrage models. In demonstrating the a...
Gaussian Affine Feature Detector
Xu, Xiaopeng; Zhang, Xiaochun
2011-01-01
A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the method is different from conventional iterative approaches. From the model, feature's parameters such as position, orientation, background luminance, contrast, area and aspect ratio can be extracted. Tested with synthesized and benchmark data, the method achieve...
On the Affine Isoperimetric Inequalities
Wuyang Yu; Gangsong Leng
2011-11-01
We obtain an isoperimetric inequality which estimate the affine invariant -surface area measure on convex bodies. We also establish the reverse version of -Petty projection inequality and an affine isoperimetric inequality of $_{-p}K$.
Adjoint affine fusion and tadpoles
Urichuk, Andrew; Walton, Mark A.
2016-01-01
We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-pol...
Gaussian Affine Feature Detector
Xu, Xiaopeng
2011-01-01
A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the method is different from conventional iterative approaches. From the model, feature's parameters such as position, orientation, background luminance, contrast, area and aspect ratio can be extracted. Tested with synthesized and benchmark data, the method achieves or outperforms existing approaches in term of accuracy, speed and stability. The method can detect small, long or thin objects precisely, and works well under general conditions, such as for low contrast, blurred or noisy images.
Affinity Purification of Insulin by Peptide-Ligand Affinity Chromatography
无
2007-01-01
The affinity heptapeptide (HWWWPAS) for insulin, selected from phage display library,was coupled to EAH Sepharose 4B gel and packed to a 1-mL column. The column was used for the affinity purification of insulin from protein mixture and commercial insulin preparation. It was observed that the minor impurity in the commercial insulin was removed by the affinity chromatography. Nearly 40 mg of insulin could be purified with the 1-mL affinity column. The results revealed the high specificity and capacity of the affinity column for insulin purification. Moreover, based on the analysis of the amino acids in the peptide sequence, shorter peptides were designed and synthesized for insulin chromatography. As a result, HWWPS was found to be a good alternative to HWWWPAS, while the other two peptides with three or four amino acids showed weak affinity for insulin. The results indicated that the peptide sequence of HWWWPAS was quite conservative for specific binding of insulin.
An affine framework for analytical mechanics
Urbanski, Pawel
2003-01-01
An affine Cartan calculus is developed. The concepts of special affine bundles and special affine duality are introduced. The canonical isomorphisms, fundamental for Lagrangian and Hamiltonian formulations of the dynamics in the affine setting are proved.
Adjoint affine fusion and tadpoles
Urichuk, Andrew; Walton, Mark A.
2016-06-01
We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.
Adjoint affine fusion and tadpoles
Urichuk, Andrew
2016-01-01
We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows, and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.
Infinite transitivity on affine varieties
Arzhantsev, Ivan; Flenner, Hubert; Kaliman, Shulim; Kutzschebauch, Frank; ZAIDENBERG, MIKHAIL
2012-01-01
In this note we survey recent results on automorphisms of affine algebraic varieties, infinitely transitive group actions and flexibility. We present related constructions and examples, and discuss geometric applications and open problems.
Representations of affine Hecke algebras
Xi, Nanhua
1994-01-01
Kazhdan and Lusztig classified the simple modules of an affine Hecke algebra Hq (q E C*) provided that q is not a root of 1 (Invent. Math. 1987). Ginzburg had some very interesting work on affine Hecke algebras. Combining these results simple Hq-modules can be classified provided that the order of q is not too small. These Lecture Notes of N. Xi show that the classification of simple Hq-modules is essentially different from general cases when q is a root of 1 of certain orders. In addition the based rings of affine Weyl groups are shown to be of interest in understanding irreducible representations of affine Hecke algebras. Basic knowledge of abstract algebra is enough to read one third of the book. Some knowledge of K-theory, algebraic group, and Kazhdan-Lusztig cell of Cexeter group is useful for the rest
In the theory of affine SL(2)-embeddings, which was constructed in 1973 by Popov, a locally transitive action of the group SL(2) on a normal affine three-dimensional variety X is determined by a pair (p/q,r), where 0GV//T-hat. In the substantiation of this result a key role is played by Cox's construction in toric geometry. Bibliography: 12 titles
Affine density in wavelet analysis
Kutyniok, Gitta
2007-01-01
In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.
Protein isolation using affinity chromatography
Besselink, T.
2012-01-01
Many product or even waste streams in the food industry contain components that may have potential for e.g. functional foods. These streams are typically large in volume and the components of interest are only present at low concentrations. A robust and highly selective separation process should be developed for efficient isolation of the components. Affinity chromatography is such a selective method. Ligands immobilized to a stationary phase (e.g., a resin or membrane) are used to bind the c...
Inhomogeneous self-affine carpets
Fraser, Jonathan M.
2013-01-01
We investigate the dimension theory of inhomogeneous self-affine carpets. Through the work of Olsen, Snigireva and Fraser, the dimension theory of inhomogeneous self-similar sets is now relatively well-understood, however, almost no progress has been made concerning more general non-conformal inhomogeneous attractors. If a dimension is countably stable, then the results are immediate and so we focus on the upper and lower box dimensions and compute these explicitly for large classes of inhomo...
Alternative affinity tools: more attractive than antibodies?
Ruigrok, V.J.B.; Levisson, M.; Eppink, M.H.M.; Smidt, H.; Oost, van der J.
2011-01-01
Antibodies are the most successful affinity tools used today, in both fundamental and applied research (diagnostics, purification and therapeutics). Nonetheless, antibodies do have their limitations, including high production costs and low stability. Alternative affinity tools based on nucleic acids
Spectral affinity in protein networks
Teng Shang-Hua
2009-11-01
Full Text Available Abstract Background Protein-protein interaction (PPI networks enable us to better understand the functional organization of the proteome. We can learn a lot about a particular protein by querying its neighborhood in a PPI network to find proteins with similar function. A spectral approach that considers random walks between nodes of interest is particularly useful in evaluating closeness in PPI networks. Spectral measures of closeness are more robust to noise in the data and are more precise than simpler methods based on edge density and shortest path length. Results We develop a novel affinity measure for pairs of proteins in PPI networks, which uses personalized PageRank, a random walk based method used in context-sensitive search on the Web. Our measure of closeness, which we call PageRank Affinity, is proportional to the number of times the smaller-degree protein is visited in a random walk that restarts at the larger-degree protein. PageRank considers paths of all lengths in a network, therefore PageRank Affinity is a precise measure that is robust to noise in the data. PageRank Affinity is also provably related to cluster co-membership, making it a meaningful measure. In our experiments on protein networks we find that our measure is better at predicting co-complex membership and finding functionally related proteins than other commonly used measures of closeness. Moreover, our experiments indicate that PageRank Affinity is very resilient to noise in the network. In addition, based on our method we build a tool that quickly finds nodes closest to a queried protein in any protein network, and easily scales to much larger biological networks. Conclusion We define a meaningful way to assess the closeness of two proteins in a PPI network, and show that our closeness measure is more biologically significant than other commonly used methods. We also develop a tool, accessible at http://xialab.bu.edu/resources/pnns, that allows the user to
Manifolds with integrable affine shape operator
Daniel A. Joaquín
2005-05-01
Full Text Available This work establishes the conditions for the existence of vector fields with the property that theirs covariant derivative, with respect to the affine normal connection, be the affine shape operatorS in hypersurfaces. Some results are obtained from this property and, in particular, for some kind of affine decomposable hypersurfaces we explicitely get the actual vector fields.
Steiner, Wolfgang
2012-01-01
An integral self-affine tile is the solution of a set equation $\\mathbf{A} \\mathcal{T} = \\bigcup_{d \\in \\mathcal{D}} (\\mathcal{T} + d)$, where $\\mathbf{A}$ is an $n \\times n$ integer matrix and $\\mathcal{D}$ is a finite subset of $\\mathbb{Z}^n$. In the recent decades, these objects and the induced tilings have been studied systematically. We extend this theory to matrices $\\mathbf{A} \\in \\mathbb{Q}^{n \\times n}$. We define rational self-affine tiles as compact subsets of the open subring $\\mathbb{R}^n\\times \\prod_\\mathfrak{p} K_\\mathfrak{p}$ of the ad\\'ele ring $\\mathbb{A}_K$, where the factors of the (finite) product are certain $\\mathfrak{p}$-adic completions of a number field $K$ that is defined in terms of the characteristic polynomial of $\\mathbf{A}$. Employing methods from classical algebraic number theory, Fourier analysis in number fields, and results on zero sets of transfer operators, we establish a general tiling theorem for these tiles. We also associate a second kind of tiles with a rational matr...
The affine quantum gravity programme
The central principle of affine quantum gravity is securing and maintaining the strict positivity of the matrix { g-hat ab(x)} composed of the spatial components of the local metric operator. On spectral grounds, canonical commutation relations are incompatible with this principle, and they must be replaced by noncanonical, affine commutation relations. Due to the partial second-class nature of the quantum gravitational constraints, it is advantageous to use the recently developed projection operator method, which treats all quantum constraints on an equal footing. Using this method, enforcement of regularized versions of the gravitational operator constraints is formulated quite naturally by means of a novel and relatively well-defined functional integral involving only the same set of variables that appears in the usual classical formulation. It is anticipated that skills and insight to study this formulation can be developed by studying special, reduced-variable models that still retain some basic characteristics of gravity, specifically a partial second-class constraint operator structure. Although perturbatively nonrenormalizable, gravity may possibly be understood nonperturbatively from a hard-core perspective that has proved valuable for specialized models. Finally, developing a procedure to pass to the genuine physical Hilbert space involves several interconnected steps that require careful coordination
Conformal field theory on affine Lie groups
Working directly on affine Lie groups, we construct several new formulations of the WZW model, the gauged WZW model, and the generic affine-Virasoro action. In one formulation each of these conformal field theories (CFTs) is expressed as a one-dimensional mechanical system whose variables are coordinates on the affine Lie group. When written in terms of the affine group element, this formulation exhibits a two-dimensional WZW term. In another formulation each CFT is written as a two-dimensional field theory, with a three- dimensional WZW term, whose fields are coordinates on the affine group. On the basis of these equivalent formulations, we develop a translation dictionary in which the new formulations on the affine Lie group are understood as mode formulations of the conventional formulations on the Lie group. Using this dictionary, we also express each CFT as a three-dimensional field theory on the Lie group with a four-dimensional WZW term. 36 refs
Conformal field theory on affine Lie groups
Clubok, K.S.
1996-04-01
Working directly on affine Lie groups, we construct several new formulations of the WZW model, the gauged WZW model, and the generic affine-Virasoro action. In one formulation each of these conformal field theories (CFTs) is expressed as a one-dimensional mechanical system whose variables are coordinates on the affine Lie group. When written in terms of the affine group element, this formulation exhibits a two-dimensional WZW term. In another formulation each CFT is written as a two-dimensional field theory, with a three- dimensional WZW term, whose fields are coordinates on the affine group. On the basis of these equivalent formulations, we develop a translation dictionary in which the new formulations on the affine Lie group are understood as mode formulations of the conventional formulations on the Lie group. Using this dictionary, we also express each CFT as a three-dimensional field theory on the Lie group with a four-dimensional WZW term. 36 refs.
Maximin affinity learning of image segmentation
Turaga, Srinivas C; Helmstaedter, Moritz; Denk, Winfried; Seung, H Sebastian
2009-01-01
Images can be segmented by first using a classifier to predict an affinity graph that reflects the degree to which image pixels must be grouped together and then partitioning the graph to yield a segmentation. Machine learning has been applied to the affinity classifier to produce affinity graphs that are good in the sense of minimizing edge misclassification rates. However, this error measure is only indirectly related to the quality of segmentations produced by ultimately partitioning the affinity graph. We present the first machine learning algorithm for training a classifier to produce affinity graphs that are good in the sense of producing segmentations that directly minimize the Rand index, a well known segmentation performance measure. The Rand index measures segmentation performance by quantifying the classification of the connectivity of image pixel pairs after segmentation. By using the simple graph partitioning algorithm of finding the connected components of the thresholded affinity graph, we are ...
Methods for Improving Aptamer Binding Affinity
Hijiri Hasegawa; Nasa Savory; Koichi Abe; Kazunori Ikebukuro
2016-01-01
Aptamers are single stranded oligonucleotides that bind a wide range of biological targets. Although aptamers can be isolated from pools of random sequence oligonucleotides using affinity-based selection, aptamers with high affinities are not always obtained. Therefore, further refinement of aptamers is required to achieve desired binding affinities. The optimization of primary sequences and stabilization of aptamer conformations are the main approaches to refining the binding properties of a...
Covariant Functional Calculi from the Affine Groups
Gong, Yafang
2009-01-01
Invoking the Clifford-Hermite Wavelets from Clifford analysis, we use the covariances of affine groups to construct a kind of functional calculi for several non-commuting bounded operators. Functional calculi are the intertwining transforms between the representations of affine groups in the space $L^2(\\mathbb R^m)$ and in the space of bounded operators. It turns out that the Weyl calculus is the value of this new functional calculus at the identity of affine groups. Our app...
Multipole solutions in metric-affine gravity
Socorro, J; Macías, A; Mielke, E W; Socorro, José; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.
1998-01-01
Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. Here, by using the harmonic map ansatz, a new class of multipole like solutions in the metric affine gravity theory (MAG) is obtained.
Maximin affinity learning of image segmentation
Srinivas C Turaga; Briggman, Kevin L; Helmstaedter, Moritz; Denk, Winfried; Seung, H. Sebastian
2009-01-01
Images can be segmented by first using a classifier to predict an affinity graph that reflects the degree to which image pixels must be grouped together and then partitioning the graph to yield a segmentation. Machine learning has been applied to the affinity classifier to produce affinity graphs that are good in the sense of minimizing edge misclassification rates. However, this error measure is only indirectly related to the quality of segmentations produced by ultimately partitioning the a...
Discrete Affine Minimal Surfaces with Indefinite Metric
Craizer, Marcos; Anciaux, Henri; Lewiner, Thomas
2008-01-01
Inspired by the Weierstrass representation of smooth affine minimal surfaces with indefinite metric, we propose a constructive process producing a large class of discrete surfaces that we call discrete affine minimal surfaces. We show that they are critical points of an affine area functional defined on the space of quadrangular discrete surfaces. The construction makes use of asymptotic coordinates and allows defining the discrete analogs of some differential geometric objects, such as the n...
A Novel Vertex Affinity for Community Detection
Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-10-05
We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.
Compact noncontraction semigroups of affine operators
Voynov, A. S.; Protasov, V. Yu
2015-07-01
We analyze compact multiplicative semigroups of affine operators acting in a finite-dimensional space. The main result states that every such semigroup is either contracting, that is, contains elements of arbitrarily small operator norm, or all its operators share a common invariant affine subspace on which this semigroup is contracting. The proof uses functional difference equations with contraction of the argument. We look at applications to self-affine partitions of convex sets, the investigation of finite affine semigroups and the proof of a criterion of primitivity for nonnegative matrix families. Bibliography: 32 titles.
Protein Complex Purification by Affinity Capture.
LaCava, John; Fernandez-Martinez, Javier; Hakhverdyan, Zhanna; Rout, Michael P
2016-01-01
Affinity capture has become a powerful technique for consistently purifying endogenous protein complexes, facilitating biochemical and biophysical assays on otherwise inaccessible biological assemblies, and enabling broader interactomic exploration. For this procedure, cells are broken and their contents separated and extracted into a solvent, permitting access to target macromolecular complexes thus released in solution. The complexes are specifically enriched from the extract onto a solid medium coupled with an affinity reagent-usually an antibody-that recognizes the target either directly or through an appended affinity tag, allowing subsequent characterization of the complex. Here, we discuss approaches and considerations for purifying endogenous yeast protein complexes by affinity capture. PMID:27371601
Structural determinants of sigma receptor affinity
The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-[3H]3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent
Structural determinants of sigma receptor affinity
Largent, B.L.; Wikstroem, H.G.; Gundlach, A.L.; Snyder, S.H.
1987-12-01
The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-(/sup 3/H)3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent.
Structure of classical affine and classical affine fractional W-algebras
We introduce a classical BRST complex (See Definition 3.2.) and show that one can construct a classical affine W-algebra via the complex. This definition clarifies that classical affine W-algebras can be considered as quasi-classical limits of quantum affine W-algebras. We also give a definition of a classical affine fractional W-algebra as a Poisson vertex algebra. As in the classical affine case, a classical affine fractional W-algebra has two compatible λ-brackets and is isomorphic to an algebra of differential polynomials as a differential algebra. When a classical affine fractional W-algebra is associated to a minimal nilpotent, we describe explicit forms of free generators and compute λ-brackets between them. Provided some assumptions on a classical affine fractional W-algebra, we find an infinite sequence of integrable systems related to the algebra, using the generalized Drinfel’d and Sokolov reduction
Scaling analysis of affinity propagation.
Furtlehner, Cyril; Sebag, Michèle; Zhang, Xiangliang
2010-06-01
We analyze and exploit some scaling properties of the affinity propagation (AP) clustering algorithm proposed by Frey and Dueck [Science 315, 972 (2007)]. Following a divide and conquer strategy we setup an exact renormalization-based approach to address the question of clustering consistency, in particular, how many cluster are present in a given data set. We first observe that the divide and conquer strategy, used on a large data set hierarchically reduces the complexity O(N2) to O(N((h+2)/(h+1))) , for a data set of size N and a depth h of the hierarchical strategy. For a data set embedded in a d -dimensional space, we show that this is obtained without notably damaging the precision except in dimension d=2 . In fact, for d larger than 2 the relative loss in precision scales such as N((2-d)/(h+1)d). Finally, under some conditions we observe that there is a value s* of the penalty coefficient, a free parameter used to fix the number of clusters, which separates a fragmentation phase (for ss*) of the underlying hidden cluster structure. At this precise point holds a self-similarity property which can be exploited by the hierarchical strategy to actually locate its position, as a result of an exact decimation procedure. From this observation, a strategy based on AP can be defined to find out how many clusters are present in a given data set. PMID:20866473
Free C+ actions on affine threefolds
Kraft, H.
2005-01-01
We study algebraic actions of the additive group C+ on an affine threefold X and prove a smoothness property for the quotient morphism X -< X//C+. Then, following Shulim Kaliman, we give a proof of the conjecture that every free C+ action on affine 3-space C^3 is a translation.
Lectures on extended affine Lie algebras
Neher, Erhard
2010-01-01
We give an introduction to the structure theory of extended affine Lie algebras, which provide a common framework for finite-dimensional semisimple, affine and toroidal Lie algebras. The notes are based on a lecture series given during the Fields Institute summer school at the University of Ottawa in June 2009.
Affine Constellations Without Mutually Unbiased Counterparts
Weigert, Stefan
2010-01-01
It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations, mostly in dimension six. The observed discrepancies make a deeper relation between the two existence problems unlikely.
Affine constellations without mutually unbiased counterparts
Weigert, Stefan [Department of Mathematics, University of York, York YO10 5DD (United Kingdom); Durt, Thomas, E-mail: slow500@york.ac.u, E-mail: thomdurt@vub.ac.b [IR-TONA, VUB, BE-1050 Brussels (Belgium)
2010-10-08
It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations. The observed discrepancies make a deeper relation between the two existence problems unlikely. (fast track communication)
Dyes with high affinity for polylactide
Liang He; Shu Fen Zhang; Bing Tao Tang; Li Li Wang; Jin Zong Yang
2007-01-01
Attempts were made to develop dyes with high affinity for polylactide as an alternative to the existent commercial disperse dyes.The dyes synthesized according to the affinity concept of dye to polylactide exhibited excellent dyeing properties on polylactide compared with the commercial disperse dyes.
Lifeng XI
2008-01-01
In this paper,it is proved that any self-affine set satisfying the strong separation condition is uniformly porous.The author constructs a self-affine set which is not porous,although the open set condition holds.Besides,the author also gives a C1 iterated function system such that its invariant set is not porous.
Affine constellations without mutually unbiased counterparts
It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations. The observed discrepancies make a deeper relation between the two existence problems unlikely. (fast track communication)
Improving image segmentation by learning region affinities
Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.
2010-11-03
We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.
Optimized Affinity Capture of Yeast Protein Complexes.
LaCava, John; Fernandez-Martinez, Javier; Hakhverdyan, Zhanna; Rout, Michael P
2016-01-01
Here, we describe an affinity isolation protocol. It uses cryomilled yeast cell powder for producing cell extracts and antibody-conjugated paramagnetic beads for affinity capture. Guidelines for determining the optimal extraction solvent composition are provided. Captured proteins are eluted in a denaturing solvent (sodium dodecyl sulfate polyacrylamide gel electrophoresis sample buffer) for gel-based proteomic analyses. Although the procedures can be modified to use other sources of cell extract and other forms of affinity media, to date we have consistently obtained the best results with the method presented. PMID:27371596
Affinity Proteomics in the mountains: Alpbach 2015.
Taussig, Michael J
2016-09-25
The 2015 Alpbach Workshop on Affinity Proteomics, organised by the EU AFFINOMICS consortium, was the 7th workshop in this series. As in previous years, the focus of the event was the current state of affinity methods for proteome analysis, including complementarity with mass spectrometry, progress in recombinant binder production methods, alternatives to classical antibodies as affinity reagents, analysis of proteome targets, industry focus on biomarkers, and diagnostic and clinical applications. The combination of excellent science with Austrian mountain scenery and winter sports engender an atmosphere that makes this series of workshops exceptional. The articles in this Special Issue represent a cross-section of the presentations at the 2015 meeting. PMID:27118167
Corner Transfer Matrices and Quantum Affine Algebras
Foda, O E; Foda, Omar; Miwa, Tetsuji
1992-01-01
Let H be the corner-transfer-matrix Hamiltonian for the six-vertex model in the anti-ferroelectric regime. It acts on the infinite tensor product W = V . V . V ....., where is the 2-dimensional irreducible representation of the quantum affine sl(2). We observe that H is the derivation of quantum affine sl(2), and conjecture that the eigenvectors of H form the level-1 vacuum representation of quantum affine sl(2). We report on checks in support of our conjecture.
Automorphisms in Birational and Affine Geometry
Ciliberto, Ciro; Flenner, Hubert; McKernan, James; Prokhorov, Yuri; Zaidenberg, Mikhail
2014-01-01
The main focus of this volume is on the problem of describing the automorphism groups of affine and projective varieties, a classical subject in algebraic geometry where, in both cases, the automorphism group is often infinite dimensional. The collection covers a wide range of topics and is intended for researchers in the fields of classical algebraic geometry and birational geometry (Cremona groups) as well as affine geometry with an emphasis on algebraic group actions and automorphism groups. It presents original research and surveys and provides a valuable overview of the current state of the art in these topics. Bringing together specialists from projective, birational algebraic geometry and affine and complex algebraic geometry, including Mori theory and algebraic group actions, this book is the result of ensuing talks and discussions from the conference “Groups of Automorphisms in Birational and Affine Geometry” held in October 2012, at the CIRM, Levico Terme, Italy. The talks at the conference high...
Synthesis of a New Series of Bone Affinity Compounds
无
2006-01-01
A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.
Affine Moment Invariants Generated by Graph Method
Suk, Tomáš; Flusser, Jan
2011-01-01
Roč. 44, č. 9 (2011), 2047 – 2056. ISSN 0031-3203 R&D Projects: GA ČR(CZ) GA102/08/1593 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image moments * Object recognition * Affine transformation * Affine moment invariants * Pseudoinvariants * Graph representation * Irreducibility * Independence Subject RIV: IN - Informatics, Computer Science Impact factor: 2.292, year: 2011 http://library.utia.cas.cz/separaty/2011/ZOI/suk-0359752.pdf
On Affine Fusion and the Phase Model
Walton, Mark A.
2012-01-01
A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the $su(n)$ Wess-Zumino-Novikov-Witten (WZNW) conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connec...
Purely affine elementary su(N) fusions
Rasmussen, Jorgen; Walton, Mark A.
2001-01-01
We consider three-point couplings in simple Lie algebras -- singlets in triple tensor products of their integrable highest weight representations. A coupling can be expressed as a linear combination of products of finitely many elementary couplings. This carries over to affine fusion, the fusion of Wess-Zumino-Witten conformal field theories, where the expressions are in terms of elementary fusions. In the case of su(4) it has been observed that there is a purely affine elementary fusion, i.e...
Complete algebraic vector fields on affine surfaces
Kaliman, Shulim; Kutzschebauch, Frank; Leuenberger, Matthias
2014-01-01
Let $\\AAutH (X)$ be the subgroup of the group $\\AutH (X)$ of holomorphic automorphisms of a normal affine algebraic surface $X$ generated by elements of flows associated with complete algebraic vector fields. Our main result is a classification of all normal affine algebraic surfaces $X$ quasi-homogeneous under $\\AAutH (X)$ in terms of the dual graphs of the boundaries $\\bX \\setminus X$ of their SNC-completions $\\bX$.
Fan affinity laws from a collision model
The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan. (paper)
A MEMS Dielectric Affinity Glucose Biosensor
Xian HUANG; Li, SiQi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao
2013-01-01
Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concent...
Affine modifications and affine hypersurfaces with a very transitive automorphism group
Kaliman, Shulim; ZAIDENBERG, MIKHAIL
1998-01-01
We study a kind of modification of an affine domain which produces another affine domain. First appeared in passing in the basic paper of O. Zariski (1942), it was further considered by E.D. Davis (1967). The first named author applied its geometric counterpart to construct contractible smooth affine varieties non-isomorphic to Euclidean spaces. Here we provide certain conditions which guarantee preservation of the topology under a modification. As an application, we show that the group of bi...
Affinity purification of aprotinin from bovine lung.
Xin, Yu; Liu, Lanhua; Chen, Beizhan; Zhang, Ling; Tong, Yanjun
2015-05-01
An affinity protocol for the purification of aprotinin from bovine lung was developed. To simulate the structure of sucrose octasulfate, a natural specific probe for aprotinin, the affinity ligand was composed of an acidic head and a hydrophobic stick, and was then linked with Sepharose. The sorbent was then subjected to adsorption analysis with pure aprotinin. The purification process consisted of one step of affinity chromatography and another step of ultrafiltration. Then purified aprotinin was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, trypsin inhibitor activity, gel-filtration, and thin-layer chromatography analysis. As calculated, the theoretical maximum adsorption (Qmax ) of the affinity sorbent was 25,476.0 ± 184.8 kallikrein inactivator unit/g wet gel; the dissociation constant of the complex "immobilized ligand-aprotinin" (Kd ) was 4.6 ± 0.1 kallikrein inactivator unit/mL. After the affinity separation of bovine lung aprotinin, reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and gel-filtration chromatography revealed that the protein was a single polypeptide, and the purities were ∼ 97 and 100%, respectively; the purified peptide was also confirmed with aprotinin standard by gel-filtration chromatography and thin-layer chromatography. After the whole purification process, protein, and bioactivity recoveries were 2.2 and 92.6%, respectively; and the specific activity was up to 15,907.1 ± 10.2 kallikrein inactivator unit/mg. PMID:25677462
Heegaard, N H; Sen, J W; Nissen, Mogens Holst
2000-01-01
The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of...
On Affine Fusion and the Phase Model
Mark A. Walton
2012-11-01
Full Text Available A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n Wess-Zumino-Novikov-Witten (WZNW conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connection to the modular S matrix and fusion of the su(n WZNW model. The noncommutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.
On affine fusion and the phase model
Walton, Mark A
2012-01-01
A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n) Wess-Zumino-Novikov-Witten (WZNW) conformal field theories appears in a simple integrable system known as the phase model. The algebraic Bethe ansatz constructs the commuting operators of the phase model as Schur polynomials, with non-commuting hopping operators as arguments. These non-commutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n) fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.
Affine Projection Algorithm Using Regressive Estimated Error
Zhang, Shu; Zhi, Yongfeng
2011-01-01
An affine projection algorithm using regressive estimated error (APA-REE) is presented in this paper. By redefining the iterated error of the affine projection algorithm (APA), a new algorithm is obtained, and it improves the adaptive filtering convergence rate. We analyze the iterated error signal and the stability for the APA-REE algorithm. The steady-state weights of the APA-REE algorithm are proved to be unbiased and consist. The simulation results show that the proposed algorithm has a f...
Control and estimation of piecewise affine systems
Xu, Jun
2014-01-01
As a powerful tool to study nonlinear systems and hybrid systems, piecewise affine (PWA) systems have been widely applied to mechanical systems. Control and Estimation of Piecewise Affine Systems presents several research findings relating to the control and estimation of PWA systems in one unified view. Chapters in this title discuss stability results of PWA systems, using piecewise quadratic Lyapunov functions and piecewise homogeneous polynomial Lyapunov functions. Explicit necessary and sufficient conditions for the controllability and reachability of a class of PWA systems are
Periodic cyclic homology of affine Hecke algebras
Solleveld, Maarten
2009-01-01
This is the author's PhD-thesis, which was written in 2006. The version posted here is identical to the printed one. Instead of an abstract, the short list of contents: Preface 5 1 Introduction 9 2 K-theory and cyclic type homology theories 13 3 Affine Hecke algebras 61 4 Reductive p-adic groups 103 5 Parameter deformations in affine Hecke algebras 129 6 Examples and calculations 169 A Crossed products 223 Bibliography 227 Index 237 Samenvatting 245 Curriculum vitae 253
Green, R. M.
1997-01-01
We introduce an analogue of the $q$-Schur algebra associated to Coxeter systems of type $\\hat A_{n-1}$. We give two constructions of this algebra. The first construction realizes the algebra as a certain endomorphism algebra arising from an affine Hecke algebra of type $\\hat A_{r-1}$, where $n \\geq r$. This generalizes the original $q$-Schur algebra as defined by Dipper and James, and the new algebra contains the ordinary $q$-Schur algebra and the affine Hecke algebra as subalgebras. Using th...
Crossing Chris: Some Markerian Affinities
Adrian Martin
2010-01-01
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Abstract (E: This essay creatively explores a group of artists, writers, and other special individuals whose work or life story can be described as having an intriguing affinity with the protean career of Chris Marker. Avoiding the ‘usual suspects’ (such as Godard or Sebald, it discusses gossip columnist Milt Machlin, record collector Harry Smith, painter Gianfranco Baruchello, writer-filmmaker Edgardo Cozarinsky, and several others. From this constellation, a particular view of Markerian poetics emerges, touching upon the meanings of anonymity, storytelling, history and archiving.
Abstract (F: Cet essai brosse de manière créative le portrait d’un groupe d'artistes, d'écrivains et d'autres personnes particulières dont le travail ou la biographie peuvent être décrits comme montrant une étrange mais certaine connivence avec la carrière protéiforme de Chris Marker. Evitant les lieux communs (comme Godard ou Sebald, cet article trace des références moins attendues :
Renhua Huang
2015-09-01
Full Text Available Often when generating recombinant affinity reagents to a target, one singles out an individual binder, constructs a secondary library of variants, and affinity selects a tighter or more specific binder. To enhance the throughput of this general approach, we have developed a more integrated strategy where the “affinity maturation” step is part of the phage-display pipeline, rather than a follow-on process. In our new schema, we perform two rounds of affinity selection, followed by error-prone PCR on the pools of recovered clones, generation of secondary libraries, and three additional rounds of affinity selection, under conditions of off-rate competition. We demonstrate the utility of this approach by generating low nanomolar fibronectin type III (FN3 monobodies to five human proteins: ubiquitin-conjugating enzyme E2 R1 (CDC34, COP9 signalosome complex subunit 5 (COPS5, mitogen-activated protein kinase kinase 5 (MAP2K5, Splicing factor 3A subunit 1 (SF3A1 and ubiquitin carboxyl-terminal hydrolase 11 (USP11. The affinities of the resulting monobodies are typically in the single-digit nanomolar range. We demonstrate the utility of two binders by pulling down the targets from a spiked lysate of HeLa cells. This integrated approach should be applicable to directed evolution of any phage-displayed affinity reagent scaffold.
Huang, Renhua; Gorman, Kevin T; Vinci, Chris R; Dobrovetsky, Elena; Gräslund, Susanne; Kay, Brian K
2015-01-01
Often when generating recombinant affinity reagents to a target, one singles out an individual binder, constructs a secondary library of variants, and affinity selects a tighter or more specific binder. To enhance the throughput of this general approach, we have developed a more integrated strategy where the "affinity maturation" step is part of the phage-display pipeline, rather than a follow-on process. In our new schema, we perform two rounds of affinity selection, followed by error-prone PCR on the pools of recovered clones, generation of secondary libraries, and three additional rounds of affinity selection, under conditions of off-rate competition. We demonstrate the utility of this approach by generating low nanomolar fibronectin type III (FN3) monobodies to five human proteins: ubiquitin-conjugating enzyme E2 R1 (CDC34), COP9 signalosome complex subunit 5 (COPS5), mitogen-activated protein kinase kinase 5 (MAP2K5), Splicing factor 3A subunit 1 (SF3A1) and ubiquitin carboxyl-terminal hydrolase 11 (USP11). The affinities of the resulting monobodies are typically in the single-digit nanomolar range. We demonstrate the utility of two binders by pulling down the targets from a spiked lysate of HeLa cells. This integrated approach should be applicable to directed evolution of any phage-displayed affinity reagent scaffold. PMID:26437402
General super Virasoro construction on affine G
We consider a bosonic current algebra and a theory of free fermions and construct a general N = 1 super Virasoro current algebra. We obtain a master-set of equations which comprises the bosonic master equation for general Virasoro construction on affine G. As an illustration we study the case of the group SU(2). (author). 13 refs
Classification of neocortical interneurons using affinity propagation
Roberto eSantana
2013-12-01
Full Text Available In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. Neuronal classification has been a difficult problem because it is unclear what a neuronal cell class actually is and what are the best characteristics are to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological or molecular characteristics, when applied to selected datasets, have provided quantitative and unbiased identification of distinct neuronal subtypes. However, better and more robust classification methods are needed for increasingly complex and larger datasets. We explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. In fact, using a combined anatomical/physiological dataset, our algorithm differentiated parvalbumin from somatostatin interneurons in 49 out of 50 cases. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.
Affinely Recursive Functions and Neural Networks
Kůrková, Věra; Kainen, P.C.
Atlanta : Georgia Institute of Technology, 1994 - ( Ames , W.), s. 776-779 [IMACS World Congress /14./. Atlanta (US), 11.07.1994-15.07.1994] R&D Projects: GA AV ČR IA23057; GA ČR GA201/93/0427 Keywords : neural networks * affinely recursive functions
Colliding waves in metric-affine gravity
García, A; Macías, A; Mielke, E W; Socorro, J; García, Alberto; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.; Socorro, José
1998-01-01
We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the collision possesses two spacelike Killing vectors.
Artificial Affinity Proteins as Ligands of Immunoglobulins
Barbara Mouratou
2015-01-01
Full Text Available A number of natural proteins are known to have affinity and specificity for immunoglobulins. Some of them are widely used as reagents for detection or capture applications, such as Protein G and Protein A. However, these natural proteins have a defined spectrum of recognition that may not fit specific needs. With the development of combinatorial protein engineering and selection techniques, it has become possible to design artificial affinity proteins with the desired properties. These proteins, termed alternative scaffold proteins, are most often chosen for their stability, ease of engineering and cost-efficient recombinant production in bacteria. In this review, we focus on alternative scaffold proteins for which immunoglobulin binders have been identified and characterized.
Improved native affinity purification of RNA.
Batey, Robert T; Kieft, Jeffrey S
2007-08-01
RNA biochemical or structural studies often require an RNA sample that is chemically pure, and most protocols for its in vitro production use denaturing polyacrylamide gel electrophoresis to achieve this. Unfortunately, many RNAs do not quantitatively refold into an active conformation after denaturation, creating significant problems for downstream characterization or use. In addition, this traditional purification method is not amenable to studies demanding high-throughput RNA production. Recently, we presented the first general method for producing almost any RNA sequence that employs an affinity tag that is removed during the purification process. Because technical difficulties prevented application of this method to many RNAs, we have developed an improved version that utilizes a different activatable ribozyme and affinity tag that are considerably more robust, rapid, and broadly applicable. PMID:17548432
AFFINITY OF LIGNIN PREPARATIONS TOWARDS GENOTOXIC COMPOUNDS
Božena Košíková
2009-02-01
Full Text Available The carcinogenicity and mutagenicity of chemicals may be modulated by other chemicals, including those prepared by organic synthesis. Consid-ering the several drawbacks of synthetic compounds vis-a-vis the human organism, the lignin biomass component was examined for this purpose. The binding affinity of lignin samples prepared by chemical and biological modification of lignin products derived from chemical wood treatment towards for N-nitrosodiethylamine (NDA was examined. The protective role of the lignin samples against carcinogenesis was tested on a well-known model carcinogen, N-methyl-N´-nitro-N-nitrosoguanidine (MNNG. The observed ability of a series of lignin preparations to reduce alkylation damage of deoxyribonucleic acid (DNA on hamster cells in vitro could be explained by their affinity to bind N-nitrosoamines. The results indicate that lignin has potential to protect living organisms against damaging effects of different genotoxicants.
Phosphopeptide enrichment by immobilized metal affinity chromatography
Thingholm, Tine E.; Larsen, Martin R.
2016-01-01
binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10–11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe 3+ for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide......Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...
High-affinity neuropeptide Y receptor antagonists.
Daniels, A J; Matthews, J. E.; Slepetis, R J; Jansen, M; Viveros, O. H.; Tadepalli, A.; Harrington, W; Heyer, D; Landavazo, A; Leban, J J
1995-01-01
Neuropeptide Y (NPY) is one of the most abundant peptide transmitters in the mammalian brain. In the periphery it is costored and coreleased with norepinephrine from sympathetic nerve terminals. However, the physiological functions of this peptide remain unclear because of the absence of specific high-affinity receptor antagonists. Three potent NPY receptor antagonists were synthesized and tested for their biological activity in in vitro, ex vivo, and in vivo functional assays. We describe he...
Staircase models from affine Toda field theory
The authors propose a class of purely elastic scattering theories generalizing the staircase model of Al. B. Zamolodchikov, based on the affine Toda field theories for simply-laced Lie algebras g = A,D,E at suitable complex values of their coupling constants. Considering their Thermodynamic Bethe Ansatz equations, they give analytic arguments in support of a conjectured renormalization group flow visiting the neighborhood of each Wg minimal model in turn
AFFINE TRANSFORMATION IN RANDOM ITERATED FUNCTION SYSTEMS
熊勇; 史定华
2001-01-01
Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, that the figure reconstructed by the new random IFS is the image of the origin figure reconstructed by old IFS under a given affine transformation. Two particular examples are used to show this approach.
Homogeneous grading affine Toda quantum solitons
Zuevsky, Alexander
Vol. 563. Bristol : IOP Science, 2014 - (Burdik, C.; Navratil, O.; Posta, S.), 012036 ISSN 1742-6588. [International Conference on Integrable Systems and Quantum Symmetries (ISQS-22) /22./. Prague (CZ), 26.06.2014-29.06.-2014] Institutional support: RVO:67985840 Keywords : exactly solvable models * conformal and affine Toda systems * quantum groups Subject RIV: BA - General Mathematics http://iopscience.iop.org/1742-6596/563/1/012036
Denominators in cluster algebras of affine type
Buan, Aslak Bakke; Marsh, Robert J.
2008-01-01
The Fomin-Zelevinsky Laurent phenomenon states that every cluster variable in a cluster algebra can be expressed as a Laurent polynomial in the variables lying in an arbitrary initial cluster. We give representation-theoretic formulas for the denominators of cluster variables in cluster algebras of affine type. The formulas are in terms of the dimensions of spaces of homomorphisms in the corresponding cluster category, and hold for any choice of initial cluster.
Thermodynamics. Using Affinities to define reversible processes
Ritacco, Hernán A
2016-01-01
In this article a definition of reversible processes in terms of differences in intensive Thermodynamics properties (Affinities) is proposed. This definition makes it possible to both define reversible processes before introducing the concept of entropy and avoid the circularity problem that follows from the Clausius definition of entropy changes. The convenience of this new definition compared to those commonly found in textbooks is demonstrated with examples.
On constructing purely affine theories with matter
Cervantes-Cota, Jorge L.; Liebscher, D.-E.
2016-08-01
We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.
On constructing purely affine theories with matter
Cervantes-Cota, Jorge L
2016-01-01
We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schroedinger's purely affine theory [21], where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.
Overview of affinity biosensors in food analysis.
Patel, Pradip D
2006-01-01
The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field. PMID:16792079
A MEMS Dielectric Affinity Glucose Biosensor.
Huang, Xian; Li, Siqi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao
2013-06-20
Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concentrations. This sensor features simplicity in sensor design, and possesses high specificity and accuracy in glucose detection. However, lack of glucose diffusion passage, this device is unable to fulfill real-time in-vivo monitoring. As a major improvement to this device, we present in this paper a fully implantable MEMS dielectric affinity glucose biosensor that contains a perforated electrode embedded in a suspended diaphragm. This capacitive-based sensor contains no moving parts, and enables glucose diffusion and real-time monitoring. The experimental results indicate that this sensor can detect glucose solutions at physiological concentrations and possesses good reversibility and reliability. This sensor has a time constant to glucose concentration change at approximately 3 min, which is comparable to commercial systems. The sensor has potential applications in fully implantable CGM that require excellent long-term stability and reliability. PMID:24511215
Phosphopeptide Enrichment by Immobilized Metal Affinity Chromatography.
Thingholm, Tine E; Larsen, Martin R
2016-01-01
Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively charged metal ions such as Fe(3+), Ga(3+), Al(3+), Zr(4+), and Ti(4+) has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from nonspecific binding of non-phosphorylated peptides. This problem is mainly caused by highly acidic peptides that also share high binding affinity towards these metal ions. By lowering the pH of the loading buffer nonspecific binding can be reduced significantly, however with the risk of reducing specific binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10-11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe(3+) for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide mixture. PMID:26584922
Quelques remarques sur la notion de modification affine
Dubouloz, Adrien
2005-01-01
in french We construct a global counterpart to the notion of affine modification due to Kaliman and Zaidenberg. This leads to a simple explicit description of the structure of birational affine morphisms between arbitrary quasi-projective varieties.
A multiscale framework for affine invariant pattern recognition and registration
Rahtu, E. (Esa)
2007-01-01
Abstract This thesis presents a multiscale framework for the construction of affine invariant pattern recognition and registration methods. The idea in the introduced approach is to extend the given pattern to a set of affine covariant versions, each carrying slightly different information, and then to apply known affine invariants to each of them separately. The key part of the framework is the construction of the affine covariant set, and this is done by combining several scaled represen...
The purification of affinity-labelled active-site peptides
The isolation of the labelled peptide from the protein digest, following the affinity labelling of the active sites of enzymes or antibodies, is described. Single-step affinity chromatography utilises the affinity of the native enzymes or antibody for the ligand used to label the same protein. The labelled peptide is the only one in the digest that displays affinity for the immobilised protein and can be released with eluants that dissociate the protein-ligand complex. (Auth.)
Duals of Affine Grassmann Codes and Their Relatives
Beelen, P.; Ghorpade, S. R.; Hoholdt, T.
2012-01-01
Affine Grassmann codes are a variant of generalized Reed-Muller codes and are closely related to Grassmann codes. These codes were introduced in a recent work by Beelen Here, we consider, more generally, affine Grassmann codes of a given level. We explicitly determine the dual of an affine Grassm...
Avoiding degenerate coframes in an affine gauge approach to quantum gravity
This report discusses the following concepts on quantum gravity: The affine gauge approach; affine gauge transformations versus active differomorphisms; affine gauge approach to quantum gravity with topology change
On Metrizability of Invariant Affine Connections
Tanaka, Erico
2011-01-01
The metrizability problem for a symmetric affine connection on a manifold, invariant with respect to a group of diffeomorphisms G, is considered. We say that the connection is G-metrizable, if it is expressible as the Levi-Civita connection of a G-invariant metric field. In this paper we analyze the G-metrizability equations for the rotation group G = SO(3), acting canonically on three- and four-dimensional Euclidean spaces. We show that the property of the connection to be SO(3)-invariant allows us to find complete explicit description of all solutions of the SO(3)-metrizability equations.
Quantum affine symmetry in vertex models
Idzumi, M; Jimbo, M; Miwa, T; Nakashima, T; Tokihiro, T; Idzumi, Makoto; Iohara, Kenji; Jimbo, Michio; Miwa, Tetsuji; Nakashima, Toshiki; Tokihiro, Tetsuji
1993-01-01
We study the higher spin anologs of the six vertex model on the basis of its symmetry under the quantum affine algebra $U_q(\\slth)$. Using the method developed recently for the XXZ spin chain, we formulate the space of states, transfer matrix, vacuum, creation/annihilation operators of particles, and local operators, purely in the language of representation theory. We find that, regardless of the level of the representation involved, the particles have spin $1/2$, and that the $n$-particle space has an RSOS-type structure rather than a simple tensor product of the $1$-particle space. This agrees with the picture proposed earlier by Reshetikhin.
Connection between the Affine and conformal Affine Toda models and their Hirota's solution
It is shown that the Affine Toda models (AT) constitute a gauge fixed version of the Conformal Affine Toda model (CAT). This result enables one to map every solution of the AT models into an infinite number of solutions of the corresponding CAT models, each one associated to a point of the orbit of the conformal group. The Hirota's τ-function are introduced and soliton solutions for the AT and CAT models associated to SL (r+1) and SP (r) are constructed. (author)
Aptamer Affinity Maturation by Resampling and Microarray Selection.
Kinghorn, Andrew B; Dirkzwager, Roderick M; Liang, Shaolin; Cheung, Yee-Wai; Fraser, Lewis A; Shiu, Simon Chi-Chin; Tang, Marco S L; Tanner, Julian A
2016-07-19
Aptamers have significant potential as affinity reagents, but better approaches are critically needed to discover higher affinity nucleic acids to widen the scope for their diagnostic, therapeutic, and proteomic application. Here, we report aptamer affinity maturation, a novel aptamer enhancement technique, which combines bioinformatic resampling of aptamer sequence data and microarray selection to navigate the combinatorial chemistry binding landscape. Aptamer affinity maturation is shown to improve aptamer affinity by an order of magnitude in a single round. The novel aptamers exhibited significant adaptation, the complexity of which precludes discovery by other microarray based methods. Honing aptamer sequences using aptamer affinity maturation could help optimize a next generation of nucleic acid affinity reagents. PMID:27346322
Induced Modules for Affine Lie Algebras
Vyacheslav Futorny
2009-03-01
Full Text Available We study induced modules of nonzero central charge with arbitrary multiplicities over affine Lie algebras. For a given pseudo parabolic subalgebra P of an affine Lie algebra G, our main result establishes the equivalence between a certain category of P-induced G-modules and the category of weight P-modules with injective action of the central element of G. In particular, the induction functor preserves irreducible modules. If P is a parabolic subalgebra with a finite-dimensional Levi factor then it defines a unique pseudo parabolic subalgebra P^{ps}, P subset P^{ps}. The structure of P-induced modules in this case is fully determined by the structure of P^{ps}-induced modules. These results generalize similar reductions in particular cases previously considered by V. Futorny, S. König, V. Mazorchuk [Forum Math. 13 (2001, 641-661], B. Cox [Pacific J. Math. 165 (1994, 269-294] and I. Dimitrov, V. Futorny, I. Penkov [Comm. Math. Phys. 250 (2004, 47-63].
Exploring Fluorous Affinity by Liquid Chromatography.
Catani, Martina; Guzzinati, Roberta; Marchetti, Nicola; Pasti, Luisa; Cavazzini, Alberto
2015-07-01
Terms such as "fluorous affinity" and "fluorophilicity" have been used to describe the unique partition and sorption properties often exhibited by highly fluorinated organic compounds, that is molecules rich in sp(3) carbon-fluorine bonds. In this work, we made use of a highly fluorinated stationary phase and a series of benzene derivatives to study the effect of one single perfluorinated carbon on the chromatographic behavior and adsorption properties of molecules. For this purpose, the adsorption equilibria of α,α,α-trifluorotoluene, toluene, and other alkylbenzenes have been studied by means of nonlinear chromatography in a variety of acetonitrile/water eluents. Our results reveal that one single perfluorinated carbon is already enough to induce a drastic change in the adsorption properties of molecules on the perfluorinated stationary phase. In particular, it has been found that adsorption is monolayer if the perfluoroalkyl carbon is present but that, when this unit is missing, molecules arrange as multilayer stack structures. These findings can contribute to the understanding of molecular mechanisms of fluorous affinity. PMID:26047527
Aspects of affine Toda field theory
The report is devoted to properties of the affine Toda field theory, the intention being to highlight a selection of curious properties that should be explicable in terms of the underlying group theory but for which in most cases there are no explanation. The motivation for exploring the ideas contained in this report came principally from the recent work of Zamolodchikov concerning the two dimensional Ising model at critical temperature perturbed by a magnetic field. Hollowood and Mansfield pointed out that since Toda field theory is conformal the perturbation considered by Zamolodchikov might well be best regarded as a perturbation of a Toda field theory. This work made it seem plausible that the theory sought by Zamolodchikov was actually affine E8 Toda field theory. However, this connection required an imaginary value of the coupling constant. Investigations here concerning exact S-matrices use a perturbative approach based on real coupling and the results differ in various ways from those thought to correspond to perturbed conformal field theory. A further motivation is to explore the connection between conformal and perturbed conformal field theories in other contexts using similar ideas. (N.K.)
Data Stream Clustering With Affinity Propagation
Zhang, Xiangliang
2014-07-09
Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.
Generalized affine transformation monoids on Galois rings
Yonglin Cao
2006-01-01
Let A be a ring with identity. The generalized affine transformation monoid Gaff(A) is defined as the set of all transformations on A of the form xÃ¢Â†Â¦xu+a (for all xÃ¢ÂˆÂˆA), where u,aÃ¢ÂˆÂˆA. We study the algebraic structure of the monoid Gaff(A) on a finite Galois ring A. The following results are obtained: an explicit description of Green's relations on Gaff(A); and an explicit description of the SchÃƒÂ¼tzenberger group of every Ã°ÂÂ’ÂŸ-class, which is shown to be isomorphic to the aff...
Gravitational Goldstone fields from affine gauge theory
Tresguerres, R
2000-01-01
In order to facilitate the application of standard renormalization techniques, gravitation should be decribed, if possible, in pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincare or the affine group. This embodies the translational as well as the linear connection. However, the coframe is not the standard Yang-Mills type gauge field of the translations, since it lacks the inhomogeneous gradient term in the gauge transformations. By explicitly restoring the "hidden" piece responsible for this behavior within the framework of nonlinear realizations, the usual geometrical interpretation of the dynamical theory becomes possible, and in addition one can avoid the metric or coframe degeneracy which would otherwise interfere with the integrations within the path integral. We claim that nonlinear realizations provide a general mathematical scheme clarifying the foundations of gauge theories of spacetime symmetries. When applied to construct the Yang-Mills theory of the aff...
Effectively nonlocal metric-affine gravity
Golovnev, Alexey; Sandstad, Marit
2015-01-01
In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with non-singular and cosmologically interesting properties may be recovered. Relations between different formulations are analysed at both perturbative and nonperturbative levels taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.
Effectively nonlocal metric-affine gravity
Golovnev, Alexey; Koivisto, Tomi; Sandstad, Marit
2016-03-01
In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.
Affine connection form of Regge calculus
Khatsymovsky, V M
2015-01-01
Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the 3-simplices which play a role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4,R) of the connection matrices. As a result, we have some action invariant w. r. t. arbitrary change of coordinates of the vertices (and related GL(4,R) transformations in...
Li, Bing; Fouts, Ashley E; Stengel, Katharina; Luan, Peng; Dillon, Michael; Liang, Wei-Ching; Feierbach, Becket; Kelley, Robert F; Hötzel, Isidro
2014-01-01
Antibodies isolated from human donors are increasingly being developed for anti-infective therapeutics. These antibodies undergo affinity maturation in vivo, minimizing the need for engineering of therapeutic leads for affinity. However, the affinities required for some therapeutic applications may be higher than the affinities of the leads obtained, requiring further affinity maturation in vitro. To improve the neutralization potency of natural human antibody MSL-109 targeting human cytomegalovirus (CMV), we affinity matured the antibody against the gH/gL glycoprotein complex. A phage display library where most of the six complementary-determining regions (CDRs) were allowed to vary in only one amino acid residue at a time was used to scan for mutations that improve binding affinity. A T55R mutation and multiple mutations in position 53 of the heavy chain were identified that, when present individually or in combination, resulted in higher apparent affinities to gH/gL and improved CMV neutralization potency of Fab fragments expressed in bacterial cells. Three of these mutations in position 53 introduced glycosylation sites in heavy chain CDR 2 (CDR H2) that impaired binding of antibodies expressed in mammalian cells. One high affinity (KD < 10 pM) variant was identified that combined the D53N and T55R mutations while avoiding glycosylation of CDR H2. However, all the amino acid substitutions identified by phage display that improved binding affinity without introducing glycosylation sites required between two and four simultaneous nucleotide mutations to avoid glycosylation. These results indicate that the natural human antibody MSL-109 is close to a local affinity optimum. We show that affinity maturation by phage display can be used to identify and bypass barriers to in vivo affinity maturation of antibodies imposed by glycosylation and codon usage. These constraints may be relatively prevalent in human antibodies due to the codon usage and the amino acid
Classical affine W-algebras associated to Lie superalgebras
In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent
Classical affine W-algebras associated to Lie superalgebras
Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)
2016-02-15
In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent.
Non-affine displacements in flexible polymer networks
Basu, Anindita; Wen, Qi; Mao, Xiaoming; Lubensky, T. C.; Janmey, Paul A.; Yodh, A. G.
2010-01-01
The validity of the affine assumption in model flexible polymer networks is explored. To this end, the displacements of fluorescent tracer beads embedded in polyacrylamide gels are quantified by confocal microscopy under shear deformation, and the deviations of these displacements from affine responses are recorded. Non-affinity within the gels is quantified as a function of polymer chain density and cross-link concentration. Observations are in qualitative agreement with current theories of ...
Affine Vertex Operator Algebras and Modular Linear Differential Equations
Arike, Yusuke; Kaneko, Masanobu; Nagatomo, Kiyokazu; Sakai, Yuichi
2016-05-01
In this paper, we list all affine vertex operator algebras of positive integral levels whose dimensions of spaces of characters are at most 5 and show that a basis of the space of characters of each affine vertex operator algebra in the list gives a fundamental system of solutions of a modular linear differential equation. Further, we determine the dimensions of the spaces of characters of affine vertex operator algebras whose numbers of inequivalent simple modules are not exceeding 20.
Affine Vertex Operator Algebras and Modular Linear Differential Equations
Arike, Yusuke; Kaneko, Masanobu; Nagatomo, Kiyokazu; Sakai, Yuichi
2016-04-01
In this paper, we list all affine vertex operator algebras of positive integral levels whose dimensions of spaces of characters are at most 5 and show that a basis of the space of characters of each affine vertex operator algebra in the list gives a fundamental system of solutions of a modular linear differential equation. Further, we determine the dimensions of the spaces of characters of affine vertex operator algebras whose numbers of inequivalent simple modules are not exceeding 20.
Extended affine Weyl groups: Presentation by conjugation via integral collection
Azam, Saeid; Shahsanaei, Valiollah
2009-01-01
We give several necessary and sufficient conditions for the existence of {\\it the presentation by conjugation} for a non-simply laced extended affine Weyl group. We invent a computational tool by which one can determine simply the existence of the presentation by conjugation for an extended affine Weyl group. As an application, we determine the existence of the presentation by conjugation for a large class of extended affine Weyl groups.
Dirac cohomology for the degenerate affine Hecke Clifford algebra
Chan, Kei Yuen
2013-01-01
We define an analogue of the Dirac operator for the degenerate affine Hecke-Clifford algebra. A main result is to relate the central characters of the degenerate affine Hecke-Clifford algebra with the central characters of the Sergeev algebra via Dirac cohomology. The action of the Dirac operator on certain modules is also computed. Results in this paper could be viewed as a projective version of the Dirac cohomology of the degenerate affine Hecke algebra.
DECISION TREE ANALYSIS OF THE PREDICTORS OF INTERNET AFFINITY
BUBAŠ, Goran; Kliček, Božidar; Hutinski, Željko
2001-01-01
A recently developed model of Internet affinity was used for survey design and data collection on variables that have potential influence on affinity for Internet use. A total of 600 Croatian students with access to the Internet at their college participated in this survey. The collected data were used for investigation of the relation between decision tree analysis and regression analysis of predictor variables of Internet affinity. Different predictors were found to influence two distinct c...
Self-affine sets and the continuity of subadditive pressure
Shmerkin, Pablo
2013-01-01
The affinity dimension is a number associated to an iterated function system of affine maps, which is fundamental in the study of the fractal dimensions of self-affine sets. De-Jun Feng and the author recently solved a folklore open problem, by proving that the affinity dimension is a continuous function of the defining maps. The proof also yields the continuity of a topological pressure arising in the study of random matrix products. I survey the definition, motivation and main properties of...
On invariant measures of finite affine type tilings
Petite, S.
2004-01-01
In this paper, we consider tilings of the hyperbolic 2-space, built with a finite number of polygonal tiles, up to affine transformation. To such a tiling T, we associate a space of tilings: the continuous hull Omega(T) on which the affine group acts. This space Omega(T) inherits a solenoid structure whose leaves correspond to the orbits of the affine group. First we prove the finite harmonic measures of this laminated space correspond to finite invariant measures for the affine group action....
Smooth affine shear tight frames: digitization and applications
Zhuang, Xiaosheng
2015-08-01
In this paper, we mainly discuss one of the recent developed directional multiscale representation systems: smooth affine shear tight frames. A directional wavelet tight frame is generated by isotropic dilations and translations of directional wavelet generators, while an affine shear tight frame is generated by anisotropic dilations, shears, and translations of shearlet generators. These two tight frames are actually connected in the sense that the affine shear tight frame can be obtained from a directional wavelet tight frame through subsampling. Consequently, an affine shear tight frame indeed has an underlying filter bank from the MRA structure of its associated directional wavelet tight frame. We call such filter banks affine shear filter banks, which can be designed completely in the frequency domain. We discuss the digitization of affine shear filter banks and their implementations: the forward and backward digital affine shear transforms. Redundancy rate and computational complexity of digital affine shear transforms are also investigated in this paper. Numerical experiments and comparisons in image/video processing show the advantages of digital affine shear transforms over many other state-of-art directional multiscale representation systems.
We further find the defining structure of a two-parameter quantum affine algebra Ur,s(sln-circumflex) (n > 2) in the sense of Benkart-Witherspoon [BW1] after the work of [BGH1], [HS] and [BH], which turns out to be a Drinfeld double. Of more importance for the 'affine' cases is that we work out the compatible two-parameter version of the Drinfeld realization as a quantum affinization of Ur,s(sln) and establish the Drinfeld isomorphism Theorem in the two-parameter setting via developing a new remarkable combinatorial approach - quantum 'affine' Lyndon basis with an explicit valid algorithm, based on the Drinfeld realization. (author)
Affinity of guanosine derivatives for polycytidylate revisited
Kanavarioti, A.; Hurley, T. B.; Baird, E. E.
1995-01-01
Evidence is presented for complexation of guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) with polycytidylate (poly(C)) at pH 8.0 and 23 degrees C in the presence of 1.0 M NaCl2 and 0.2 M MgCl2 in water. The association of 2-MeImpG with poly(C) was investigated using UV-vis spectroscopy as well as by monitoring the kinetics of the nucleophilic substitution reaction of the imidazole moiety by amines. The results of both methods are consistent with moderately strong poly(C) 2-MeImpG complexation and the spectrophotometric measurements allowed the construction of a binding isotherm with a concentration of 2-MeImpG equal to 5.55 +/- 0.15 mM at half occupancy. UV spectroscopy was employed to establish the binding of other guanosine derivatives on poly(C). These derivatives are guanosine 5'-monophosphate (5'GMP), guanosine 5'-monophosphate imidazolide (ImpG), and guanosine 5'-monophosphate morpholidate (morpG). Within experimental error these guanosine derivatives exhibit the same affinity for poly(C) as 2-MeImpG.
Affine group formulation of the Standard Model coupled to gravity
In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauder’s affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant Λ, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and Yang–Mills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the Yang–Mills and Higgs energy densities, are composed with York’s integrated time functional. The result, when combined with the imaginary part of the Chern–Simons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: •Wheeler–DeWitt equation (WDW) quantized as affine algebra, realizing Klauder’s program. •WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. •WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. •Constructed a family of physical states for the full, coupled theory via affine coherent states. •Fundamental uncertainty relation, predicated on non-vanishing cosmological constant
Synthesis of tetracycline analogs and their bone affinities
Wen Cai Huang; Hu Zheng; Ling Ling Weng
2008-01-01
Tetracycline analogs were designed and synthesized and their bone affinities were tested on hydroxyapatite. The results showedthat the carbonyl-amide-enol structure in A ring and phenol-ketone structure in BCD ring may be responsible for tetracycline's highbone affinity and either A ring or BCD ring has a planar conformation is essential.
Self-affine roughness influence on redox reaction charge admittance
Palasantzas, G
2005-01-01
In this work we investigate the influence of self-affine electrode roughness on the admittance of redox reactions during facile charge transfer kinetics. The self-affine roughness is characterized by the rms roughness amplitude w, the correlation length xi and the roughness exponent H (0
Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators
Fields, Jessica; Copp, Martha
2015-01-01
Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…
Tending to Change: Toward a Situated Model of Affinity Spaces
Bommarito, Dan
2014-01-01
The concept of affinity spaces, a theoretical construct used to analyze literate activity from a spatial perspective, has gained popularity among scholars of literacy studies and, particularly, video-game studies. This article seeks to expand current notions of affinity spaces by identifying key assumptions that have limited researchers'…
IMPLEMENTASI ENKRIPSI DEKRIPSI ALGORITMA AFFINE CIPHER BERBASIS ANDROID
Sasono Wibowo
2014-11-01
Full Text Available Perkembangan Teknologi Informasi yang cukup pesat khususnya dalam bidang komunikasi menjadikan komunikasi sangat mudah namun dalam implementasinya perlu adanya keamanan tentang informasi yang disampaikan. Dalam komunikasi antar orang pasti memiliki pembicaraan informasi yang bersifat privat atau orang lain tidak boleh tahu tentang pembicaraan yang terjadi. Diperlukannya keamanan untuk menjaga kerahasiaan informasi pada saat komunikasi. Masyarakat lebih sering menggunakan komunikasi dengan telepon seluler karena dinilai mudah dibawa dan tidak repot menggunakannya. Kriptografi yang biasa dikenal sebagai ilmu yang mempelajari bagaimana cara menyembunyikan pesan bisa diterapkan dalam aplikasi pada telepon seluler sebagai contoh smartphone android. Dengan mengimplementasikan algoritma affine cipher maka aplikasi yang akan dibuat bisa mengubah isi pesan yang ada dan dapat mengamankan informasi yang ada. Algoritma affine cipher merupakan perkembangan dari algoritma caesar dimana algoritma affine cipher menggunakan dua kunci. Dengan mengimplementasikan algoritma affine cipher ke dalam android maka diharapkan kita bisa menyimpan informasi dari siapapun tanpa terbaca. Kata Kunci : Kriptografi, Affine Cipher, android, Implementasi, Informasi
Chasing polys: Interdisciplinary affinity and its connection to physics identity
Scott, Tyler D.
This research is based on two motivations that merge by means of the frameworks of interdisciplinary affinity and physics identity. First, a goal of education is to develop interdisciplinary abilities in students' thinking and work. But an often ignored factor is students interests and beliefs about being interdisciplinary. Thus, this work develops and uses a framework called interdisciplinary affinity. It encompasses students interests in making connections across disciplines and their beliefs about their abilities to make those connections. The second motivation of this research is to better understand how to engage more students with physics. Physics identity describes how a student sees themselves in relation to physics. By understanding how physics identity is developed, researchers and educators can identify factors that increase interest and engagement in physics classrooms. Therefore, physics identity was used in conjunction with interdisciplinary affinity. Using a mixed methods approach, this research used quantitative data to identify the relationships interdisciplinary affinity has with physics identity and the physics classroom. These connections were explored in more detail using a case study of three students in a high school physics class. Results showed significant and positive relationships between interdisciplinary affinity and physics identity, including the individual interest and recognition components of identity. It also identified characteristics of physics classrooms that had a significant, positive relationship with interdisciplinary affinity. The qualitative case study highlighted the importance of student interest to the relationship between interdisciplinary affinity and physics identity. It also identified interest and mastery orientation as key to understanding the link between interdisciplinary affinity and the physics classroom. These results are a positive sign that by understanding interdisciplinary affinity and physics identity
Convulsant bicuculline modifies CNS muscarinic receptor affinity
Rodríguez de Lores Arnaiz Georgina
2006-04-01
Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process
Electron affinities of atoms, molecules, and radicals
We review briefly but comprehensively the theoretical, semiempirical and experimental methods employed to determine electron affinities (EAs) of atoms, molecules and radicals, and summarize the EA data obtained by these methods. The detailed processes underlying the principles of the experimental methods are discussed very briefly. It is, nonetheless, instructive to recapitulate the definition of EA and those of the related quantities, namely, the vertical detachment energy, VDE, and the vertical attachment energy, VAE. The EA of an atom is defined as the difference in total energy between the ground state of the neutral atom (plus the electron at rest at infinity) and its negative ion. The EA of a molecule is defined as the difference in energy between the neutral molecule plus an electron at rest at infinity and the molecular negative ion when both, the neutral molecules and the negative ion, are in their ground electronic, vibrational and rotational states. The VDE is defined as the minimum energy required to eject the electron from the negative ion (in its ground electronic and nuclear state) without changing the internuclear separation; since the vertical transition may leave the neutral molecule in an excited vibrational/rotational state, the VDE, although the same as the EA for atoms is, in general, different (larger than), from the EA for molecules. Similarly, the VAE is defined as the difference in energy between the neutral molecule in its ground electronic, vibrational and rotational states plus an electron at rest at infinity and the molecular negative ion formed by addition of an electron to the neutral molecule without allowing a change in the intermolecular separation of the constituent nuclei; it is a quantity appropriate to those cases where the lowest negative ion state lies above the ground states of the neutral species and is less or equal to EA
Tetrahydroprotoberberine alkaloids with dopamine and σ receptor affinity.
Gadhiya, Satishkumar; Madapa, Sudharshan; Kurtzman, Thomas; Alberts, Ian L; Ramsey, Steven; Pillarsetty, Nagavara-Kishore; Kalidindi, Teja; Harding, Wayne W
2016-05-01
Two series of analogues of the tetrahydroprotoberberine (THPB) alkaloid (±)-stepholidine that (a) contain various alkoxy substituents at the C10 position and, (b) were de-rigidified with respect to (±)-stepholidine, were synthesized and evaluated for affinity at dopamine and σ receptors in order to evaluate effects on D3 and σ2 receptor affinity and selectivity. Small n-alkoxy groups are best tolerated by D3 and σ2 receptors. Among all compounds tested, C10 methoxy and ethoxy analogues (10 and 11 respectively) displayed the highest affinity for σ2 receptors as well as σ2 versus σ1 selectivity and also showed the highest D3 receptor affinity. De-rigidification of stepholidine resulted in decreased affinity at all receptors evaluated; thus the tetracyclic THPB framework is advantageous for affinity at dopamine and σ receptors. Docking of the C10 analogues at the D3 receptor, suggest that an ionic interaction between the protonated nitrogen atom and Asp110, a H-bond interaction between the C2 phenol and Ser192, a H-bond interaction between the C10 phenol and Cys181 as well as hydrophobic interactions of the aryl rings to Phe106 and Phe345, are critical for high affinity of the compounds. PMID:27032890
Genetic Algorithm-based Affine Parameter Estimation for Shape Recognition
Yuxing Mao
2014-06-01
Full Text Available Shape recognition is a classically difficult problem because of the affine transformation between two shapes. The current study proposes an affine parameter estimation method for shape recognition based on a genetic algorithm (GA. The contributions of this study are focused on the extraction of affine- invariant features, the individual encoding scheme, and the fitness function construction policy for a GA. First, the affine-invariant characteristics of the centroid distance ratios (CDRs of any two opposite contour points to the barycentre are analysed. Using different intervals along the azimuth angle, the different numbers of CDRs of two candidate shapes are computed as representations of the shapes, respectively. Then, the CDRs are selected based on predesigned affine parameters to construct the fitness function. After that, a GA is used to search for the affine parameters with optimal matching between candidate shapes, which serve as actual descriptions of the affine transformation between the shapes. Finally, the CDRs are resampled based on the estimated parameters to evaluate the similarity of the shapes for classification. The experimental results demonstrate the robust performance of the proposed method in shape recognition with translation, scaling, rotation and distortion.
Einstein-Maxwell dynamics as a P(4) affine theory
In Newtonian mechanics the energy of a particle is defined only up to an arbitrary additive constant. By using affine functions to model the Newtonian energy we show that it is possible to reformulate arbitrary time- and velocity-independent forces as R1 affine gauge potentials. Solutions of Newton's second law then define R1 affine energy geodesics, and the R1 flat gauge potentials are shown to correspond to conservative Newtonian forces. We generalize these ideas to relativistic mechanics by modeling the energy-momentum of classical particles as R4 affine four-vectors. If this R4 affine structure is to be compatible with the O(1,3) Riemannian structure of spacetime, then the R4 gauge potential must correspond to an antisymmetric tensor field on spacetime, and this field is identified with the electromagnetic field tensor. We are eventually led to a reformulation of the Einstein-Maxwell theory as a P(4) = O(1,3) x R4 affine gauge theory in which the timelike affine geodesics correspond to Lorentz-force-law trajectories, and the Einstein-Maxwell field equations are reformulated as gauge field equations in terms of the P(4) curvature
Affine deformation tensor - a necessary object in GRT
Einstein notions about the nature of gravitation are refined. The geometric gravitation theory (GGT) grounds are discussed. It is noted that there is no one of the important geometrical object in the Einstein gravitation theory (EGT) i.e. background affinity, which along with the metric tensor determines the gravitational gield energy density. Considering that it is not necessary to introduce background metrics, the author has introduced the background affinity and affine deformation tensor. The theory of black holes is considered as an alternative of EGT. 53 refs
Synthesis and Image Matching On Structural Patterns Using Affine Transformation
S.Vandana
2012-06-01
Full Text Available This paper focuses in explaining a Fourier based affine estimator which is applied to the task of Image Synthesis. An affine transformation is an important class of linear 2-D geometric transformations which maps variables into new by applying a linear combination of translation, rotation, scaling and/or shearing operations. Conventional retrieval systems are very effective when knowledge information and query information are in a uniform orientation but fails in recognition when effects such as scaling, orientation exist. But as this technique is based on texture analysis, which is termed the affine estimator, it will even match the images with non-uniform orientation.
Affinity- and topology-dependent bound on current fluctuations
Pietzonka, Patrick; Seifert, Udo
2016-01-01
We provide a proof of a recently conjectured universal bound on current fluctuations in Markovian processes. This bound establishes a link between the fluctuations of an individual observable current, the cycle affinities driving the system into a non-equilibrium steady state, and the topology of the network. The proof is based on a decomposition of the network into independent cycles with both positive affinity and positive stationary cycle current. This formalism allows for a refinement of the bound for systems in equilibrium or with locally vanishing affinities.
Pepsin-modified chiral monolithic column for affinity capillary electrochromatography.
Hong, Tingting; Chi, Cuijie; Ji, Yibing
2014-11-01
Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation. PMID:25146884
ODE/IM correspondence and modified affine Toda field equations
Ito, Katsushi
2014-01-01
We study the two-dimensional affine Toda field equations for affine Lie algebra $\\hat{\\mathfrak{g}}$ modified by a conformal transformation and the associated linear equations. In the conformal limit, the associated linear problem reduces to a (pseudo-)differential equation. For classical affine Lie algebra $\\hat{\\mathfrak{g}}$, we obtain a (pseudo-)differential equation corresponding to the Bethe equations for the Langlands dual of the Lie algebra $\\mathfrak{g}$, which were found by Dorey et al. in study of the ODE/IM correspondence.
Centro-affine hypersurface immersions with parallel cubic form
HILDEBRAND, Roland
2012-01-01
We consider non-degenerate centro-affine hypersurface immersions in R^n whose cubic form is parallel with respect to the Levi-Civita connection of the affine metric. There exists a bijective correspondence between homothetic families of proper affine hyperspheres with center in the origin and with parallel cubic form, and K\\"ochers conic omega-domains, which are the maximal connected sets consisting of invertible elements in a real semi-simple Jordan algebra. Every level surface of the omega ...
Roy, Ipsita; Mondal, Kalyani; Gupta, Munishwar N
2014-01-01
This chapter describes two simple interrelated non-chromatographic methods of protein purification. In the first method, called affinity precipitation, inherent affinity of reversibly soluble-insoluble polymers (also called stimuli-sensitive or smart polymers) is exploited to form an affinity complex in free solution with target protein. The affinity complex is precipitated by a suitable change in the medium. The desired protein is dissociated from the smart polymer. In the second method called macro (affinity ligand)-facilitated three phase partitioning (MLFTPP), the affinity complex is precipitated at an interface between upper t-butanol-rich phase and lower aqueous phase. These three phases are achieved by adding appropriate amounts of ammonium sulfate and t-butanol to the initial crude extract. In the first protocol, sequential MLFTPP is used with two different smart polymers to purify pectinase and cellulase from a single crude preparation. The second protocol illustrates the application of the affinity precipitation in simultaneous purification and refolding of a urea-denatured xylanase. PMID:24648072
Volatility Components, Affine Restrictions and Non-Normal Innovations
Christoffersen, Peter; Jacobs, Kris; Dorian, Christian;
Recent work by Engle and Lee (1999) shows that allowing for long-run and short-run components greatly enhances a GARCH model's ability fit daily equity return dynamics. Using the risk-neutralization in Duan (1995), we assess the option valuation performance of the Engle-Lee model and compare it to...... GARCH models to four conditionally non-normal versions. As in Hsieh and Ritchken (2005), we find that non-affine models dominate affine models both in terms of fitting return and in terms of option valuation. For the affine models we find strong evidence in favor of the component structure for both...... returns and options, but for the non-affine models the evidence is much less strong in option valuation. The evidence in favor of the non-normal models is strong when fitting daily returns, but the non-normal models do not provide much improvement when valuing options....
Antibody Affinity Maturation in Fishes—Our Current Understanding
Magor, Brad G.
2015-01-01
It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine deaminase (AID). We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes. PMID:26264036
Antibody Affinity Maturation in Fishes-Our Current Understanding.
Magor, Brad G
2015-01-01
It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine deaminase (AID). We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes. PMID:26264036
Rigid affine surfaces with isomorphic A2-cylinders
Dubouloz, Adrien
2015-01-01
We construct families of smooth affine surfaces with pairwise non isomorphic A 1-cylinders but whose A 2-cylinders are all isomorphic. These arise as complements of cuspidal hyperplane sections of smooth projective cubic surfaces.
Note on Dilogarithm Identities from Nilpotent Double Affine Hecke Algebras
Tomoki Nakanishi
2012-12-01
Full Text Available Recently Cherednik and Feigin [arXiv:1209.1978] obtained several Rogers-Ramanujan type identities via the nilpotent double affine Hecke algebras (Nil-DAHA. These identities further led to a series of dilogarithm identities, some of which are known, while some are left conjectural. We confirm and explain all of them by showing the connection with Y-systems associated with (untwisted and twisted quantum affine Kac-Moody algebras.
An affine sphere equation associated to Einstein toric surfaces
Mabuchi, Toshiki
2007-01-01
As seen in the works of Calabi, Cheng-Yau and Loftin, affine sphere equations have a close relationship with Kaehler-Einstein metrics. The main purpose of this note is to show that an equation analogous to those of hyperbolic affine spheres arises naturally from Kaehler-Einstein metrics on Einstein toric surfaces. The case for the remaining toric surfaces with Kaehler-Ricci solitons will also be discussed.
The ABC's of affine Grassmannians and Hall-Littlewood polynomials
Dalal, Avinash J.; Morse, Jennifer
2016-01-01
We give a new description of the Pieri rule for k-Schur functions using the Bruhat order on the affine type-A Weyl group. In doing so, we prove a new combinatorial formula for representatives of the Schubert classes for the cohomology of affine Grassmannians. We show how new combinatorics involved in our formulas gives the Kostka-Foulkes polynomials and discuss how this can be applied to study the transition matrices between Hall-Littlewood and k-Schur functions.
Peculiarities of Matter Motion in Metric-Affine Gravitational Theory
Babourova, O. V.; Frolov, B. N.; Koroliov, M. Yu.
1995-01-01
On the basis of the Lie derivative method in a metric-affine space-time it is shown that in the metric-affine gravitational theory the energy-momentum conservation law and therefore the equations of the matter motion are the consequence (as in the GR) of the gravitational field equations. The possi- bility of the detection of the space-time non-metric properties is discussed.
Euclidean Reconstruction and Affine Camera Calibration Using Controlled Robot Motions
Horaud, Radu; Christy, Stéphane; Mohr, Roger
1997-01-01
We are addressing the problem of Euclidean reconstruction with an uncalibrated affine camera and the calibration of this camera. We investigate constraints under which the Euclidean shape and motion problem becomes linear. The theoretical study described in this paper leads us to impose some practical constraints that the camera is mounted onto a robot arm and that the robot is executing controlled motions whose parameters are known. The affine camera model considered here is just an approxim...
Algebraic volume density property of affine algebraic manifolds
Kaliman, Shulim; Kutzschebauch, Frank
2009-01-01
We introduce the notion of algebraic volume density property for affine algebraic manifolds and prove some important basic facts about it, in particular that it implies the volume density property. The main results of the paper are producing two big classes of examples of Stein manifolds with volume density property. One class consists of certain affine modifications of $\\C^n$ equipped with a canonical volume form, the other is the class of all Linear Algebraic Groups equipped with the left i...
Quantized gauge-affine gravity in the superfiber bundle approach
Meziane, A.; Tahiri, M
2004-01-01
The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfibre bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensional general affine group double-covering to the Poincare group double-covering we also find the BRST and anti-BRST transformations of the f...
Affine invariant texture analysis based on structural properties
Zhang, Jianguo; Tan, Tieniu
2002-01-01
This paper presents a new texture analysis method based on structural properties. The texture features extracted using this algorithm are invariant to affine transform (including rotation, translation, scaling, and skewing). Affine invariant structural properties are derived based on texel areas. An area-ratio map utilizing these properties is introduced to characterize texture images. Histogram based on this map is constructed for texture classification. Efficiency of this algorithm for affi...
Several Affinity Tags Commonly Used in Chromatographic Purification
Xinyu Zhao; Guoshun Li; Shufang Liang
2013-01-01
Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP) tag, calmodulin-binding peptide (CBP), glutathione S...
Skein Modules from Skew Howe Duality and Affine Extensions
Queffelec, Hoel
2013-01-01
We show that we can release the rigidity of the skew Howe duality process for ${\\mathfrak sl}_n$ knot invariants by rescaling the quantum Weyl group action, and recover skein modules for web-tangles. This skew Howe duality phenomenon can be extended to the affine ${\\mathfrak sl}_m$ case, corresponding to looking at tangles embedded in a solid torus. We investigate the relations between the invariants constructed by evaluation representations (and affinization of them) and usual skein modules,...
Minimum information about a protein affinity reagent (MIAPAR).
Bourbeillon, Julie; Orchard, Sandra; Benhar, Itai; Borrebaeck, Carl; de Daruvar, Antoine; Dübel, Stefan; Frank, Ronald; Gibson, Frank; Gloriam, David; Haslam, Niall; Hiltker, Tara; Humphrey-Smith, Ian; Hust, Michael; Juncker, David; Koegl, Manfred
2010-01-01
We wish to alert your readers to MIAPAR, the minimum information about a protein affinity reagent. This is a proposal developed within the community as an important first step in formalizing standards in reporting the production and properties of protein binding reagents, such as antibodies, developed and sold for the identification and detection of specific proteins present in biological samples. It defines a checklist of required information, intended for use by producers of affinity reagen...
Affinity Solvents for Intensified Organics Extraction: Development Challenges and Prospects
无
2006-01-01
In most organics extraction processes, the commonly used solvents employ solely physical interactions. Therefore, for the recovery and purification of products from complex mixtures, the selectivity and/or capacity of classical solvents towards the desired solutes is usually insufficient, enforcing the need for complex and thus expensive separation schemes. Significant simplification and cost-reduction can be achieved when affinity solvents would be available that are able to recognize the solutes of interest by their molecular structure. The main development challenges to establish such affinity solvents are: Selection and incorporation of molecular recognition and complexation capabilities; Evaluation of extraction capabilities; Efficient recovery and recycling of the affinity solvents; Implementation in industrial extraction equipment. This paper presents how these development challenges are addressed at the University of Twente, going all the way from affinity solvent design and synthesis, via high throughput screening and characterization up to pilot plant evaluation. Essential in the successful development of affinity solvents are structural cooperations with molecular chemists and custom synthesis companies for their design and synthesis. The various aspects are illustrated by several examples where newly developed environmentally benign affinity solvents appeared able to create major breakthroughs. The applications addressed involve oxygenates, sugars, and pharmaceutical ingredients, such as optical isomers and biomolecules.
Kool, J.; N. Jonker; Irth, H.; Niessen, W.M.A.
2011-01-01
This review discusses the most important current methods employing mass spectrometry (MS) analysis for the study of protein affinity interactions. The methods are discussed in depth with particular reference to MS-based approaches for analyzing protein–protein and protein–immobilized ligand interactions, analyzed either directly or indirectly. First, we introduce MS methods for the study of intact protein complexes in the gas phase. Next, pull-down methods for affinity-based analysis of prote...
Increased hemoglobin O2 affinity protects during acute hypoxia.
Yalcin, Ozlem; Cabrales, Pedro
2012-08-01
Acclimatization to hypoxia requires time to complete the adaptation mechanisms that influence oxygen (O(2)) transport and O(2) utilization. Although decreasing hemoglobin (Hb) O(2) affinity would favor the release of O(2) to the tissues, increasing Hb O(2) affinity would augment arterial O(2) saturation during hypoxia. This study was designed to test the hypothesis that pharmacologically increasing the Hb O(2) affinity will augment O(2) transport during severe hypoxia (10 and 5% inspired O(2)) compared with normal Hb O(2) affinity. RBC Hb O(2) affinity was increased by infusion of 20 mg/kg of 5-hydroxymethyl-2-furfural (5HMF). Control animals received only the vehicle. The effects of increasing Hb O(2) affinity were studied in the hamster window chamber model, in terms of systemic and microvascular hemodynamics and partial pressures of O(2) (Po(2)). Pimonidazole binding to hypoxic areas of mice heart and brain was also studied. 5HMF decreased the Po(2) at which the Hb is 50% saturated with O(2) by 12.6 mmHg. During 10 and 5% O(2) hypoxia, 5HMF increased arterial blood O(2) saturation by 35 and 48% from the vehicle group, respectively. During 5% O(2) hypoxia, blood pressure and heart rate were 58 and 30% higher for 5HMF compared with the vehicle. In addition, 5HMF preserved microvascular blood flow, whereas blood flow decreased to 40% of baseline in the vehicle group. Consequently, perivascular Po(2) was three times higher in the 5HMF group compared with the control group at 5% O(2) hypoxia. 5HMF also reduced heart and brain hypoxic areas in mice. Therefore, increased Hb O(2) affinity resulted in hemodynamics and oxygenation benefits during severe hypoxia. This acute acclimatization process may have implications in survival during severe environmental hypoxia when logistic constraints prevent chronic acclimatization. PMID:22636677
Isotope shift in the electron affinity of beryllium
The study of the isotope shift in the electron affinity is interesting for probing correlation effects. Experiments that allow this property to be measured are rare, being difficult to realize, while accurate calculations remain a challenge for atomic theory. The present work focuses on the theoretical estimation of the isotope shift in the electron affinity of Be (2s2p 3Po), using correlated electronic wavefunctions obtained from multiconfiguration Hartree-Fock and configuration interaction variational calculations. The reliability of the correlation models is assessed from a comparison between the observed and theoretical electron affinities, and between theoretical isotope shift values for the 2s2p 3Po 2s21S transition of neutral beryllium. The sign and the magnitude of the difference between the mass polarization term expectation values obtained for the neutral atom and the negative ion are such that the resulting isotope shift in the electron affinity is 'anomalous', corresponding to a smaller electron affinity for the heavier isotope
Coenzyme-like ligands for affinity isolation of cholesterol oxidase.
Xin, Yu; Lu, Liushen; Wang, Qing; Zhang, Ling; Tong, Yanjun; Wang, Wu
2016-05-15
Two coenzyme-like chemical ligands were designed and synthesized for affinity isolation of cholesterol oxidase (COD). To simulate the structure of natural coenzyme of COD (flavin adenine dinucleotide (FAD)), on Sepharose beads, 5-aminouracil, cyanuric chloride and 1, 4-butanediamine were composed and then modified. The COD gene from Brevibacterium sp. (DQ345780) was expressed in Escherichia coli BL21 (DE3), and then the sorbents were applied to adsorption analysis with the pure enzyme. Subsequently, the captured enzyme was applied to SDS-PAGE and activity analysis. As calculated, the theoretical maximum adsorption (Qmax) of the two affinity sorbents (RL-1 and RL-2) were ∼83.5 and 46.3mg/g wet gel; and the desorption constant Kd of the two sorbents were ∼6.02×10(-4) and 1.19×10(-4)μM. The proteins after cell lysis were applied to affinity isolation, and then after one step of affinity binding on the two sorbents, the protein recoveries of RL-1 and RL-2 were 9.2% and 9.7%; the bioactivity recoveries were 92.7% and 91.3%, respectively. SDS-PAGE analysis revealed that the purities of COD isolated with the two affinity sorbents were approximately 95%. PMID:26856529
Bulbeck, David
2013-01-01
Genetic research into Southeast Asia's "negritos" has revealed their deep-rooted ancestry, with time depth comparable to that of Southwest Pacific populations. This finding is often interpreted as evidence that negritos, in contrast to other Southeast Asians, can trace much of their ancestry directly back to the early dispersal of Homo sapiens in the order of 70 kya from Africa to Pleistocene New Guinea and Australia. One view on negritos is to lump them and Southwest Pacific peoples into an "Australoid" race whose geographic distribution had included Southeast Asia prior to the Neolithic incursion of "Mongoloid" farmers. Studies into Semang osteology have revealed some hints of Southwest Pacific affinities in cranial shape, dental morphology, and dental metrical "shape." On the other hand, the Andamanese have been shown to resemble Africans in their craniometrics and South Asians in their dental morphology, while Philippine negritos resemble Mongoloid Southeast Asians in these respects and also in their dental metrics. This study expands the scope of negrito cranial comparisons by including Melayu Malays and additional coverage of South Asians. It highlights the distinction between the Mongoloid-like Philippine negritos and the Andamanese and Semang (and Senoi of Malaya) with their non-Mongoloid associations. It proposes that the early/mid-Holocene dispersal of the B4a1a mitochondrial DNA clade across Borneo, the Philippines, and Taiwan may be important for understanding the distinction between Philippine and other negritos. PMID:24297222
k-Schur functions and affine Schubert calculus
Lam, Thomas; Morse, Jennifer; Schilling, Anne; Shimozono, Mark; Zabrocki, Mike
2014-01-01
This book gives an introduction to the very active field of combinatorics of affine Schubert calculus, explains the current state of the art, and states the current open problems. Affine Schubert calculus lies at the crossroads of combinatorics, geometry, and representation theory. Its modern development is motivated by two seemingly unrelated directions. One is the introduction of k-Schur functions in the study of Macdonald polynomial positivity, a mostly combinatorial branch of symmetric function theory. The other direction is the study of the Schubert bases of the (co)homology of the affine Grassmannian, an algebro-topological formulation of a problem in enumerative geometry. This is the first introductory text on this subject. It contains many examples in Sage, a free open source general purpose mathematical software system, to entice the reader to investigate the open problems. This book is written for advanced undergraduate and graduate students, as well as researchers, who want to become familiar with ...
Enhancing Community Detection By Affinity-based Edge Weighting Scheme
Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-10-05
Community detection refers to an important graph analytics problem of finding a set of densely-connected subgraphs in a graph and has gained a great deal of interest recently. The performance of current community detection algorithms is limited by an inherent constraint of unweighted graphs that offer very little information on their internal community structures. In this paper, we propose a new scheme to address this issue that weights the edges in a given graph based on recently proposed vertex affinity. The vertex affinity quantifies the proximity between two vertices in terms of their clustering strength, and therefore, it is ideal for graph analytics applications such as community detection. We also demonstrate that the affinity-based edge weighting scheme can improve the performance of community detection algorithms significantly.
Semisupervised Clustering for Networks Based on Fast Affinity Propagation
Mu Zhu
2013-01-01
Full Text Available Most of the existing clustering algorithms for networks are unsupervised, which cannot help improve the clustering quality by utilizing a small number of prior knowledge. We propose a semisupervised clustering algorithm for networks based on fast affinity propagation (SCAN-FAP, which is essentially a kind of similarity metric learning method. Firstly, we define a new constraint similarity measure integrating the structural information and the pairwise constraints, which reflects the effective similarities between nodes in networks. Then, taking the constraint similarities as input, we propose a fast affinity propagation algorithm which keeps the advantages of the original affinity propagation algorithm while increasing the time efficiency by passing only the messages between certain nodes. Finally, by extensive experimental studies, we demonstrate that the proposed algorithm can take fully advantage of the prior knowledge and improve the clustering quality significantly. Furthermore, our algorithm has a superior performance to some of the state-of-art approaches.
Single-cell measurement of red blood cell oxygen affinity
Caprio, Di; Higgins, John M; Schonbrun, Ethan
2015-01-01
Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...
Properties of the Affine Invariant Ensemble Sampler in high dimensions
Huijser, David; Brewer, Brendon J
2015-01-01
We present theoretical and practical properties of the affine-invariant ensemble sampler Markov chain Monte Carlo method. In high dimensions the affine-invariant ensemble sampler shows unusual and undesirable properties. We demonstrate this with an $n$-dimensional correlated Gaussian toy problem with a known mean and covariance structure, and analyse the burn-in period. The burn-in period seems to be short, however upon closer inspection we discover the mean and the variance of the target distribution do not match the expected, known values. This problem becomes greater as $n$ increases. We therefore conclude that the affine-invariant ensemble sampler should be used with caution in high dimensional problems. We also present some theoretical results explaining this behaviour.
Evaluation Codes from an Affine Veriety Code Perspective
Geil, Hans Olav
2008-01-01
Evaluation codes (also called order domain codes) are traditionally introduced as generalized one-point geometric Goppa codes. In the present paper we will give a new point of view on evaluation codes by introducing them instead as particular nice examples of affine variety codes. Our study...... includes a reformulation of the usual methods to estimate the minimum distances of evaluation codes into the setting of affine variety codes. Finally we describe the connection to the theory of one-pointgeometric Goppa codes. Contents 4.1 Introduction...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 4.2 Affine variety codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 4.3 Some Gr¨obner basis theoretical tools . . . . . . . . . . . . . . . . . . . . . . . 155 4.4 A bound on the minimum distance of C(I,L) . . . . . . . . . . . . . . . . . . 157 4.5 The Feng-Rao bound for...
Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin
Renata Angeli
2009-01-01
Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.
Ferromagnetic levan composite: an affinity matrix to purify lectin.
Angeli, Renata; da Paz, Nathalia V N; Maciel, Jackeline C; Araújo, Flávia F B; Paiva, Patrícia M G; Calazans, Glícia M T; Valente, Ana Paula; Almeida, Fábio C L; Coelho, Luana C B B; Carvalho, Luiz B; Silva, Maria da Paz C; dos Santos Correia, Maria Tereza
2009-01-01
A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column. PMID:19547713
Extremely high negative electron affinity of diamond via magnesium adsorption
O'Donnell, Kane M.; Edmonds, Mark T.; Tadich, Anton; Thomsen, Lars; Stacey, Alastair; Schenk, Alex; Pakes, Chris I.; Ley, Lothar
2015-01-01
We report large negative electron affinity (NEA) on diamond (100) using magnesium adsorption on a previously oxygen-terminated surface. The measured NEA is up to $(-2.01\\pm0.05)$ eV, the largest reported negative electron affinity to date. Despite the expected close relationship between the surface chemistry of Mg and Li species on oxygen-terminated diamond, we observe differences in the adsorption properties between the two. Most importantly, a high-temperature annealing step is not required...
Combinatorial topology of three-dimensional self-affine tiles
Bandt, Christoph
2010-01-01
We develop tools to study the topology and geometry of self-affine fractals in dimension three and higher. We use the self-affine structure and obtain rather detailed information about the connectedness of interior and boundary sets, and on the dimensions and intersections of boundary sets. As an application, we describe in algebraic terms the polyhedral structure of the six fractal three-dimensional twindragons. Only two of them can be homeomorphic to a ball but even these have faces which are not homeomorphic to a disk.
and as Vertex Operator Extensionsof Dual Affine Algebras
Bowcock, P.; Feigin, B. L.; Semikhatov, A. M.; Taormina, A.
We discover a realisation of the affine Lie superalgebra and of the exceptional affine superalgebra as vertex operator extensions of two algebras with ``dual'' levels (and an auxiliary level-1 algebra). The duality relation between the levels is . We construct the representation of on a sum of tensor products of , , and modules and decompose it into a direct sum over the spectral flow orbit. This decomposition gives rise to character identities, which we also derive. The extension of the construction to is traced to the properties of embeddings into and their relation with the dual pairs. Conversely, we show how the representations are constructed from representations.
SMOOTH AFFINE SURFACES WITH NON-UNIQUE C*-ACTIONS
Flenner, Hubert; Kaliman, Shulim; ZAIDENBERG, MIKHAIL
2008-01-01
In this paper we complete the classification of effective C*-actions on smooth affine surfaces up to conjugation in the full automorphism group and up to inversion of C*. If a smooth affine surface V admits more than one C*-action then it is known to be Gizatullin i.e., it can be completed by a linear chain of smooth rational curves. In our previous paper we gave a sufficient condition, in terms of the Dolgachev- Pinkham-Demazure (or DPD) presentation, for the uniqueness of a C*-action on a G...
Algebraic volume density property of affine algebraic manifolds
Kaliman, Shulim
2009-01-01
We introduce the notion of algebraic volume density property for affine algebraic manifolds and prove some important basic facts about it, in particular that it implies the volume density property. The main results of the paper are producing two big classes of examples of Stein manifolds with volume density property. One class consists of certain affine modifications of $\\C^n$ equipped with a canonical volume form, the other is the class of all Linear Algebraic Groups equipped with the left invariant volume form.
Affine Moment Invariants Generated by Automated Solution of the Equations
Suk, Tomáš; Flusser, Jan
Los Alamitos : IEEE Press, 2008, s. 3270-3273. ISBN 978-1-4244-2174-9. [19th International Conference on Pattern Recognition. Tampa (US), 07.12.2008-11.12.2008] R&D Projects: GA ČR GA102/08/1593 Institutional research plan: CEZ:AV0Z10750506 Keywords : affine moment invariants * object recognition * Cayley-Aronhold differential equation Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2008/ZOI/suk-affine moment invariants generated by automated solution of the equations. pdf
Affine diffusions and related processes simulation, theory and applications
Alfonsi, Aurélien
2015-01-01
This book gives an overview of affine diffusions, from Ornstein-Uhlenbeck processes to Wishart processes and it considers some related diffusions such as Wright-Fisher processes. It focuses on different simulation schemes for these processes, especially second-order schemes for the weak error. It also presents some models, mostly in the field of finance, where these methods are relevant and provides some numerical experiments. The book explains the mathematical background to understand affine diffusions and analyze the accuracy of the schemes.
Double affine Hecke algebras and 2-dimensional local fields
Kapranov, M.
1998-01-01
We give an interpretation of the double affine Hecke algebra of Cherednik as the (suitably regularized) algebra of double cosets of a group G by a subgroup J, extending the well known interpretations of finite and affine Hecke algebras. In this interpretation, G consists of K-points of a split reductive group where K is a 2-dimensional local field such as Q_p((t)) or F_q((t_1))((t_2)), and J is a certain analog of the Iwahori subgroup.
Affinity based and molecularly imprinted cryogels: Applications in biomacromolecule purification.
Andaç, Müge; Galaev, Igor Yu; Denizli, Adil
2016-05-15
The publications in macro-molecularly imprinted polymers have increased drastically in recent years with the development of water-based polymer systems. The macroporous structure of cryogels has allowed the use of these materials within different applications, particularly in affinity purification and molecular imprinting based methods. Due to their high selectivity, specificity, efficient mass transfer and good reproducibility, molecularly imprinted cryogels (MICs) have become attractive for researchers in the separation and purification of proteins. In this review, the recent developments in affinity based cryogels and molecularly imprinted cryogels in protein purification are reviewed comprehensively. PMID:26454622
Kinetic controlled affinity labeling of target enzyme with thioester chemistry.
Tomohiro, Takenori; Nakabayashi, Masahiro; Sugita, Yuka; Morimoto, Shota
2016-08-01
High specificity has been an important feature in affinity labeling for target profiling. Especially, to label targets via rapidly progressing reactions with consumption of ligand (probe), high specificity of reaction with common functional groups of target protein should be achieved without reactions with similar groups of non-target proteins. Herein, we demonstrate the kinetic controlled affinity labeling of acyl CoA synthetase using a fatty acid analogue containing a phenylthioester linkage. High specificity was attained by accelerating the labeling rate in the binding pocket. This approach could be useful for profiling a series of target enzymes and transporters in signal transduction pathways. PMID:27298000
Affine Hecke algebras associated to Kac-Moody groups
Garland, H
1995-01-01
In this paper we give a geometric construction of Cherednik's double affine Hecke algebra. We construct the algebra as the equivariant K-theory of the Lagrangian subvariety of the cotangent variety of the square of the flag variety of G, the variety being given by the union of the conormal bundles to the G-orbits on \\flag\\times\\flag. This is a generalisation of work of Kazhdan and Lusztig to the Kac-Moody case, and is suitable for describing a certain class of modules for this algebra. In a paper in preparation we will do this, in the case G is affine (Cherednik's case).
Multiple poes and other features of affine Toda field theory
Some perturbative features of affine Toda field theory are explored, in particular the mechanisms responsible for the first-, second- and third-order poles in the conjectured exact factorisable S-matrices in the ADE series of models. It is found that generic collections of Feynman diagrams are responsible for the leading order poles in any of the theories. However, the complexity is such that it has not yet proved possible to analyse all the singularities that occur up to order twelve. Some comments are made on an associated tiling problem and on an interesting connection between the affine Toda couplings and the Clebsch-Gordan decomposition of tensor products. (orig.)
A Comment on a Novel Approach for the Registration of Weak Affine Images
Flusser, Jan; Zitová, Barbara
2013-01-01
Roč. 34, č. 12 (2013), s. 1381-1385. ISSN 0167-8655 R&D Projects: GA ČR GAP103/11/1552 Keywords : Image registration * Affine transform * Affine subgroups * Weak affine transform * Area-preserving affine transform Subject RIV: JD - Computer Applications, Robotics Impact factor: 1.062, year: 2013 http://library.utia.cas.cz/separaty/2013/ZOI/flusser-a comment on a novel approach for the registration of weak affine images.pdf
A molecular determinant of phosphoinositide affinity in mammalian TRPV channels.
Velisetty, Phanindra; Borbiro, Istvan; Kasimova, Marina A; Liu, Luyu; Badheka, Doreen; Carnevale, Vincenzo; Rohacs, Tibor
2016-01-01
Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is an important cofactor for ion channels. Affinity for this lipid is a major determinant of channel inhibition by depletion of PI(4,5)P2 upon phospholipase C (PLC) activation. Little is known about what determines PI(4,5)P2 affinity in mammalian ion channels. Here we report that two members of the Transient Receptor Potential Vanilloid (TRPV) ion channel family, TRPV5 and TRPV6 lack a positively charged residue in the TM4-TM5 loop that was shown to interact with PI(4,5)P2 in TRPV1, which shows high affinity for this lipid. When this positively charged residue was introduced to either TRPV6 or TRPV5, they displayed markedly higher affinities for PI(4,5)P2, and were largely resistant to inhibition by PI(4,5)P2 depletion. Furthermore, Ca(2+)-induced inactivation of TRPV6 was essentially eliminated in the G488R mutant, showing the importance of PLC-mediated PI(4,5)P2 depletion in this process. Computational modeling shows that the introduced positive charge interacts with PI(4,5)P2 in TRPV6. PMID:27291418
Affine Toda Solitons and Systems of Calogero-Moser Type
Braden, H. W.; Hone, Andrew N. W.
1996-01-01
The solitons of affine Toda field theory are related to the spin-generalised Ruijsenaars-Schneider (or relativistic Calogero-Moser) models. This provides the sought after extension of the correspondence between the sine-Gordon solitons and the Ruijsenaars-Schneider model.
On representation theory of affine Hecke algebras of type B
Miemietz, Vanessa
2007-01-01
Ariki's and Grojnowski's approach to the representation theory of affine Hecke algebras of type $A$ is applied to type $B$ with unequal parameters to obtain -- under certain restrictions on the eigenvalues of the lattice operators -- analogous multiplicity-one results and a classification of irreducibles with partial branching rules as in type $A$.
Soliton solutions for higher grading affine Toda from quantum algebras
Zuevsky, Alexander
Bristol: IOP, 2015, 012001. ISSN 1755-1307. [2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014). Bali (ID), 11.10.2014-12.10.2014] Institutional support: RVO:67985840 Keywords : Lie algebra s * integrable models * affine Toda model Subject RIV: BA - General Mathematics http://iopscience.iop.org/1755-1315/23/1/012001
PP-waves with torsion and metric-affine gravity
Pasic, Vedad; Vassiliev, Dmitri
2005-01-01
A classical pp-wave is a 4-dimensional Lorentzian spacetime which admits a nonvanishing parallel spinor field; here the connection is assumed to be Levi-Civita. We generalise this definition to metric compatible spacetimes with torsion and describe basic properties of such spacetimes. We use our generalised pp-waves for constructing new explicit vacuum solutions of quadratic metric-affine gravity.
Electrochemical affinity biosensors for detection of mycotoxins: A review.
Vidal, Juan C; Bonel, Laura; Ezquerra, Alba; Hernández, Susana; Bertolín, Juan R; Cubel, Carlota; Castillo, Juan R
2013-11-15
This review discusses the current state of electrochemical biosensors in the determination of mycotoxins in foods. Mycotoxins are highly toxic secondary metabolites produced by molds. The acute toxicity of these results in serious human and animal health problems, although it has been only since early 1960s when the first studied aflatoxins were found to be carcinogenic. Mycotoxins affect a broad range of agricultural products, most important cereals and cereal-based foods. A majority of countries, mentioning especially the European Union, have established preventive programs to control contamination and strict laws of the permitted levels in foods. Official methods of analysis of mycotoxins normally requires sophisticated instrumentation, e.g. liquid chromatography with fluorescence or mass detectors, combined with extraction procedures for sample preparation. For about sixteen years, the use of simpler and faster analytical procedures based on affinity biosensors has emerged in scientific literature as a very promising alternative, particularly electrochemical (i.e., amperometric, impedance, potentiometric or conductimetric) affinity biosensors due to their simplicity and sensitivity. Typically, electrochemical biosensors for mycotoxins use specific antibodies or aptamers as affinity ligands, although recombinant antibodies, artificial receptors and molecular imprinted polymers show potential utility. This article deals with recent advances in electrochemical affinity biosensors for mycotoxins and covers complete literature from the first reports about sixteen years ago. PMID:23743326
Canonical bases and affine Hecke algebras of type B
Varagnolo, Michela
2009-01-01
We prove a series of conjectures of Enomoto and Kashiwara on canonical bases and branching rules of affine Hecke algebras of type B. The main ingredient of the proof is a new graded Ext-algebra associated with quiver with involutions that we compute explicitly.
Immobilized metal affinity chromatography of phosphorylated proteins using highperformance sorbents
Novotná, L.; Hrubý, Martin; Beneš, Milan J.; Kučerová, Z.
2008-01-01
Roč. 68, 5-6 (2008), s. 381-386. ISSN 0009-5893 Grant ostatní: GA MŠk(CZ) LC06044 Institutional research plan: CEZ:AV0Z40500505 Keywords : immobilized metal affinity chromatography * phosphorylation * metal ions Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.312, year: 2008
Study of pepsin phosphorylation using immobilized metal affinity chromatography
Novotná, L.; Hrubý, Martin; Beneš, Milan J.; Kučerová, Z.
2008-01-01
Roč. 31, č. 10 (2008), s. 1662-1668. ISSN 1615-9306 Institutional research plan: CEZ:AV0Z40500505 Keywords : Fe(III) * Ga(III) * immobilized metal affinity chromatography * modification of carboxyl groups Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.746, year: 2008
Several Affinity Tags Commonly Used in Chromatographic Purification
Xinyu Zhao
2013-01-01
Full Text Available Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP tag, calmodulin-binding peptide (CBP, glutathione S-transferase (GST, maltose-binding protein (MBP, S-tag, HA tag, and c-Myc tag. In some cases, a large-size affinity tag, such as GST or MBP, can significantly impact on the structure and biological activity of the fusion partner protein. So it is usually necessary to excise the tag by protease. The most commonly used endopeptidases are enterokinase, factor Xa, thrombin, tobacco etch virus, and human rhinovirus 3C protease. The proteolysis features of these proteases are described in order to provide a general guidance on the proteolytic removal of the affinity tags.
Toward an Affinity Space Methodology: Considerations for Literacy Research
Lammers, Jayne C.; Curwood, Jen Scott; Magnifico, Alecia Marie
2012-01-01
As researchers seek to make sense of young people's online literacy practices and participation, questions of methodology are important to consider. In our work to understand the culture of physical, virtual and blended spheres that adolescents inhabit, we find it necessary to expand Gee's (2004) notion of affinity spaces. In this article, we draw…
Self-Affine Sets with Positive Lebesgue Measure
Dajani, Karma; Jiang, Kan; Kempton, Tom
2014-01-01
Using techniques introduced by C. G ̈unt ̈urk, we prove that the attractors of a family of overlapping self-affine iterated function systems contain a neighbourhood of zero for all parameters in a certain range. This corresponds to giving conditions under which a single sequence may serve as a ‘simu
Native Elution of Yeast Protein Complexes Obtained by Affinity Capture.
LaCava, John; Fernandez-Martinez, Javier; Rout, Michael P
2016-01-01
This protocol describes two options for the native (nondenaturing) elution of protein complexes obtained by affinity capture. The first approach involves the elution of complexes purified through a tag that includes a human rhinovirus 3C protease (PreScission protease) cleavage site sequence between the protein of interest and the tag. Incubation with the protease cleaves immobilized complexes from the affinity medium. The second approach involves the release of protein A-tagged protein complexes using a competitive elution reagent called PEGylOx. The degree of purity of the native assemblies eluted is sample dependent and strongly influenced by the affinity capture. It should be noted that the efficiency of native elution is commonly lower than that of elution by a denaturing agent (e.g., SDS) and the release of the complex will be limited by the activity of the protease or the inhibition constant (Ki) of the competitive release agent. However, an advantage of native release is that some nonspecifically bound materials tend to stay adsorbed to the affinity medium, providing an eluted fraction of higher purity. Finally, keep in mind that the presence of the protease or elution peptide could potentially affect downstream applications; thus, their removal should be considered. PMID:27371597
Harmonic fusion and pitch affinity: Is there a direct link?
Bonnard, Damien; Dauman, René; Semal, Catherine; Demany, Laurent
2016-03-01
Simultaneous pure tones approximately one octave apart tend to be fused perceptually and to evoke a single pitch sensation. Besides, sequentially presented pure tones show a subjective "affinity" or similarity in pitch when their frequency ratio is close to one octave. The aim of the study reported here was to determine if these two perceptual phenomena are directly related. Each stimulus was a triplet of simultaneous or successive pure tones forming frequency ratios varying across stimuli between 0.96 and 1.04 octaves. The tones were presented at a low sensation level (15 dB) within broadband threshold-equalizing noise, in order to prevent them from interacting in the cochlea when they were simultaneous. A large set of stimulus comparisons made by 18 listeners indicated that: (1) when the tones were simultaneous, maximal fusion was obtained for a mean frequency ratio deviating by less than 0.2% from one octave, and fusion decreased less rapidly above this frequency ratio than below it; (2) when the tones were presented successively, maximal pitch affinity was obtained for a mean frequency ratio significantly larger than one octave, and pitch affinity decreased more rapidly above this frequency ratio than below it. The differences between the results obtained for simultaneous and successive tones suggest that harmonic fusion and pitch affinity are unrelated phenomena. PMID:26341475
Soliton-preserving boundary condition in affine Toda field theories
Delius, Gustav W
1998-01-01
We give a new integrable boundary condition in affine Toda theory which is soliton-preserving in the sense that a soliton hitting the boundary is reflected as a soliton. All previously known integrable boundary conditions forced a soliton to be converted into an antisoliton upon reflection. We prove integrability of our boundary condition using a generalization of Sklyanin's formalism.
Demazure modules and vertex models the affine sl(2) case
Foda, O E; Okado, M; Foda, Omar; Misra, Kailash C; Okado, Masato
1996-01-01
We characterize, in the case of affine sl(2), the crystal base of the Demazure module E_w(\\La) in terms of extended Young diagrams or paths for any dominant integral weight \\La and Weyl group element w. Its character is evaluated via two expressions, 'bosonic' and 'fermionic'.
Demazure modules and vertex models: the affine sl(2) case
Foda, Omar; Misra, Kailash C.; Okado, Masato
1996-01-01
We characterize, in the case of affine sl(2), the crystal base of the Demazure module E_w(\\La) in terms of extended Young diagrams or paths for any dominant integral weight \\La and Weyl group element w. Its character is evaluated via two expressions, 'bosonic' and 'fermionic'.
Soliton solutions for higher grading affine Toda from quantum algebras
Zuevsky, Alexander
Bristol : IOP, 2015, 012001. ISSN 1755-1307. [2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014). Bali (ID), 11.10.2014-12.10.2014] Institutional support: RVO:67985840 Keywords : Lie algebra s * integrable models * affine Toda model Subject RIV: BA - General Mathematics http://iopscience.iop.org/1755-1315/23/1/012001
Combinatorial Vector Fields for Piecewise Affine Control Systems
Wisniewski, Rafal; Larsen, Jesper Abildgaard
2008-01-01
This paper is intended to be a continuation of Habets and van Schuppen (2004) and Habets, Collins and van Schuppen (2006), which address the control problem for piecewise-affine systems on an arbitrary polytope or a family of these. Our work deals with the underlying combinatorics of the underlyi...
Linear independence measure of logarithms over affine groups
Huicochea, Mario
2015-01-01
Linear forms in logarithms over connected commutative algebraic groups over the algebraic numbers field have been studied widely. However, the theory of linear forms in logarithms over noncommutative algebraic groups have not been developed as the one of the commutative algebraic groups and in this paper we start studying linear forms in logarithms over affine groups.
An Affine Invariant $k$-Nearest Neighbor Regression Estimate
Biau, Gérard; Dujmovic, Vida; Krzyzak, Adam
2012-01-01
We design a data-dependent metric in $\\mathbb R^d$ and use it to define the $k$-nearest neighbors of a given point. Our metric is invariant under all affine transformations. We show that, with this metric, the standard $k$-nearest neighbor regression estimate is asymptotically consistent under the usual conditions on $k$, and minimal requirements on the input data.
Smooth surfaces from bilinear patches: Discrete affine minimal surfaces
Käferböck, Florian
2013-06-01
Motivated by applications in freeform architecture, we study surfaces which are composed of smoothly joined bilinear patches. These surfaces turn out to be discrete versions of negatively curved affine minimal surfaces and share many properties with their classical smooth counterparts. We present computational design approaches and study special cases which should be interesting for the architectural application. 2013 Elsevier B.V.
Myoglobin oxygen affinity in aquatic and terrestrial birds and mammals.
Wright, Traver J; Davis, Randall W
2015-07-01
Myoglobin (Mb) is an oxygen binding protein found in vertebrate skeletal muscle, where it facilitates intracellular transport and storage of oxygen. This protein has evolved to suit unique physiological needs in the muscle of diving vertebrates that express Mb at much greater concentrations than their terrestrial counterparts. In this study, we characterized Mb oxygen affinity (P50) from 25 species of aquatic and terrestrial birds and mammals. Among diving species, we tested for correlations between Mb P50 and routine dive duration. Across all species examined, Mb P50 ranged from 2.40 to 4.85 mmHg. The mean P50 of Mb from terrestrial ungulates was 3.72±0.15 mmHg (range 3.70-3.74 mmHg). The P50 of cetaceans was similar to terrestrial ungulates ranging from 3.54 to 3.82 mmHg, with the exception of the melon-headed whale, which had a significantly higher P50 of 4.85 mmHg. Among pinnipeds, the P50 ranged from 3.23 to 3.81 mmHg and showed a trend for higher oxygen affinity in species with longer dive durations. Among diving birds, the P50 ranged from 2.40 to 3.36 mmHg and also showed a trend of higher affinities in species with longer dive durations. In pinnipeds and birds, low Mb P50 was associated with species whose muscles are metabolically active under hypoxic conditions associated with aerobic dives. Given the broad range of potential globin oxygen affinities, Mb P50 from diverse vertebrate species appears constrained within a relatively narrow range. High Mb oxygen affinity within this range may be adaptive for some vertebrates that make prolonged dives. PMID:25987728
Novel trends in affinity biosensors: current challenges and perspectives
Molecular biorecognition processes facilitate physical and biochemical interactions between molecules in all crucial metabolic pathways. Perhaps the target analyte and the biorecognition element interactions have the most impactful use in biosensing applications. Traditional analytical sensing systems offer excellent biorecognition elements with the ability to detect and determine the presence of analytes. High affinity antibodies and DNA play an important role in the development of affinity biosensors based on electrochemical, optical and mass sensitive approaches. Advancements in this area routinely employ labels, label free, nanoparticles, multifunctional matrices, carbon nanotubes and other methods to meet the requirements of its own application. However, despite increasing affinity ceilings for conventional biosensors, the field draws back in meeting specifically important demands, such as long-term stability, ultrasensitivity, rapid detection, extreme selectivity, strong biological base, calibration, in vivo measurements, regeneration, satisfactory performance and ease of production. Nevertheless, recent efforts through this line have produced novel high-tech nanosensing systems such as ‘aptamers’ and ‘phages’ which exhibit high-throughput sensing. Aptamers and phages are powerful tools that excel over antibodies in sensibility, stability, multi-detection, in vivo measurements and regeneration. Phages are superior in stability, screening for affinity-based target molecules ranging from small to proteins and even cells, and easy production. In this review, we focus mainly on recent developments in affinity-based biosensors such as immunosensors, DNA sensors, emphasizing aptasensors and phage-based biosensors basing on novel electrochemical, optical and mass sensitive detection techniques. We also address enzyme inhibition-based biosensors and the current problems associated with the above sensors and their future perspectives. (topical review)
Chou, Beverly; Mirau, Peter; Jiang, Tian; Wang, Szu-Wen; Shea, Kenneth J
2016-05-01
Hydrophobic interactions often dominate the associative forces between biomacromolecules. A synthetic affinity reagent must be able to exploit and optimize these interactions. We describe synthesis of abiotic affinity reagents that sequester biomacromolecules with lipid-like domains. NIPAm-based copolymer nanoparticles (NPs) containing C4-C8 hydrophobic groups were evaluated for their affinity for lipopolysaccharides (LPS), the lipophilic component of the outer membrane of Gram-negative bacteria. Optimal affinity was found for NPs incorporating a linear C4 hydrocarbon group. 1D and 2D (1)H NMR studies revealed that in water, the longer chain (C6 and C8) alkyl groups in the hydrogel NPs were engaged in intrachain association, rendering them less available to interact with LPS. Optimal LPS-NP interaction requires maximizing hydrophobicity, while avoiding side chain aggregation. Polymer compositions with high LPS binding were grafted onto agarose beads and evaluated for LPS clearance from solution; samples containing linear C4 groups also showed the highest LPS clearance capacity. PMID:27064286
The Weyl-Cartan Space Problem in Purely Affine Theory
von Borzeszkowski, Horst-Heino; Treder, Hans-Jürgen
1997-04-01
According to Poincaré, only the ``epistemological sum of geometry and physics is measurable". Of course, there are requirements of measurement to be imposed on geometry because otherwise the theory resting on this geometry cannot be physically interpreted. In particular, the Weyl--Cartan space problem must be solved, i.e., it must be guaranteed that the comparison of distances is compatible with the Levi-Civita transport. In the present paper, we discuss these requirements of measurement and show that in the (purely affine) Einstein-Schrödinger unified field theory the solution of the Weyl-Cartan space problem simultaneously determines the matter via Einstein's equations. Here the affine field $\\Gamma^ikl$ represents Poincaré's sum, and the solution of the space problem means its splitting in a metrical space and in matter fields, where the latter are given by the torsion tensor $\\Gamma^i_{[kl]}$.
Improved Energy-Momentum Currents in Metric-Affine Spacetime
Hecht, R D; McCrea, J D; Mielke, E W; Ne'eman, Yuval; Hecht, Ralf; Hehl, Friedrich W.; Mielke, Eckehard W.; Ne'eman, Yuval
1992-01-01
In Minkowski spacetime it is well-known that the canonical energy-momentum current is involved in the construction of the globally conserved currents of energy-momentum and total angular momentum. For the construction of conserved currents corresponding to (approximate) scale and proper conformal symmetries, however, an improved energy-momentum current is needed. By extending the Minkowskian framework to a genuine metric-affine spacetime, we find that the affine Noether identities and the conformal Killing equations enforce this improvement in a rather natural way. So far, no gravitational dynamics is involved in our construction. The resulting dilation and proper conformal currents are conserved provided the trace of the energy-momentum current satisfies a (mild) scaling relation or even vanishes.
The affine theory of gravitation and electromagnetism I
Poplawski, N J
2006-01-01
The affine variational principle of Eddington generates the Einstein field equations of general relativity in vacuum with a non-zero cosmological constant. We generalize this principle to include electromagnetism, obtaining the Einstein--Maxwell field equations and the Lorentz equation of motion. We vary the action with respect to the quantities that appear in the definition of the electromagnetic covariant derivative: the affine (nonsymmetric) connection and the electromagnetic potential, while the Lagrangian density is taken to be the square root of the determinant of a linear combination of the symmetrized Ricci tensor and the electromagnetic field tensor. This construction generates a symmetric metric tensor and a connection with torsion that depends only on the torsion vector. The whole formulation is valid only for very weak electromagnetic fields on the order of the magnetic field in interstellar space.
An angular momentum conserving Affine-Particle-In-Cell method
Jiang, Chenfanfu; Teran, Joseph
2016-01-01
We present a new technique for transferring momentum and velocity between particles and grid with Particle-In-Cell (PIC) calculations which we call Affine-Particle-In-Cell (APIC). APIC represents particle velocities as locally affine, rather than locally constant as in traditional PIC. We show that this representation allows APIC to conserve linear and angular momentum across transfers while also dramatically reducing numerical diffusion usually associated with PIC. Notably, conservation is achieved with lumped mass, as opposed to the more commonly used Fluid Implicit Particle (FLIP) transfers which require a 'full' mass matrix for exact conservation. Furthermore, unlike FLIP, APIC retains a filtering property of the original PIC and thus does not accumulate velocity modes on particles as FLIP does. In particular, we demonstrate that APIC does not experience velocity instabilities that are characteristic of FLIP in a number of Material Point Method (MPM) hyperelasticity calculations. Lastly, we demonstrate th...
Affinity of four polar neurotransmitters for lipid bilayer membranes
Wang, Chunhua; Ye, Fengbin; Valardez, Gustavo F.;
2011-01-01
Weak interactions of neurotransmitters and the lipid matrix in the synaptic membrane have been hypothesized to play a role in synaptic transmission of nerve signals, particularly with respect to receptor desensitization (Cantor, R. S. Biochemistry 2003, 42, 11891). The strength of such interactions......, however, was not measured, and this is an obvious impediment for further evaluation and understanding of a possible role for desensitization. We have used dialysis equilibrium to directly measure the net affinity of selected neurotransmitters for lipid membranes and analyzed this affinity data with...... respect to calorimetric measurements and molecular dynamics simulations. We studied an anionic (glutamate), a cationic (acetylcholine), and two zwitterionic (-aminobutyric acid and glycine) neurotransmitters, and membranes of pure dimyristoyl phosphatidylcholine (DMPC), DMPC doped with 10% anionic lipid...
On purely transmitting defects in affine Toda field theory
Corrigan, E
2007-01-01
Affine Toda field theories with a purely transmitting integrable defect are considered and the model based on a_2 is analysed in detail. After providing a complete characterization of the problem in a classical framework, a suitable quantum transmission matrix, able to describe the interaction between an integrable defect and solitons, is found. Two independent paths are taken to reach the result. One is an investigation of the triangle equations using the S-matrix for the imaginary coupling bulk affine Toda field theories proposed by Hollowood, and the other uses a functional integral approach together with a bootstrap procedure. Evidence to support the results is collected in various ways: for instance, through the calculation of the transmission factors for the lightest breathers. While previous discoveries within the sine-Gordon model motivated this study, there are several new phenomena displayed in the a_2 model including intriguing disparities between the classical and the quantum pictures. For example...
Del Pezzo surfaces and affine 7-brane backgrounds
Hauer, T; Hauer, Tamas; Iqbal, Amer
2000-01-01
A map between string junctions in the affine 7-brane backgrounds and vector bundles on del Pezzo surfaces is constructed using mirror symmetry. It is shown that the lattice of string junctions with support on an affine 7-brane configuration is isomorphic to the K-theory group of the corresponding del Pezzo surface. This isomorphism allows us to construct a map between the states of the N=2, D=4 theories with E_N global symmetry realized in two different ways in Type IIB and Type IIA string theory. A subgroup of the SL(2,Z) symmetry of the \\hat{E}_9 7-brane background appears as the Fourier-Mukai transform acting on the D-brane configurations realizing vector bundles on elliptically fibered B_9.
Evolution based on chromosome affinity from a network perspective
Monteiro, R. L. S.; Fontoura, J. R. A.; Carneiro, T. K. G.; Moret, M. A.; Pereira, H. B. B.
2014-06-01
Recent studies have focused on models to simulate the complex phenomenon of evolution of species. Several studies have been performed with theoretical models based on Darwin's theories to associate them with the actual evolution of species. However, none of the existing models include the affinity between individuals using network properties. In this paper, we present a new model based on the concept of affinity. The model is used to simulate the evolution of species in an ecosystem composed of individuals and their relationships. We propose an evolutive algorithm that incorporates the degree centrality and efficiency network properties to perform the crossover process and to obtain the network topology objective, respectively. Using a real network as a starting point, we simulate its evolution and compare its results with the results of 5788 computer-generated networks.
Affinity purification of proteins binding to GST fusion proteins.
Swaffield, J C; Johnston, S A
2001-05-01
This unit describes the use of proteins fused to glutathione-S-transferase (GST fusion proteins) to affinity purify other proteins, a technique also known as GST pulldown purification. The describes a strategy in which a GST fusion protein is bound to agarose affinity beads and the complex is then used to assay the binding of a specific test protein that has been labeled with [35S]methionine by in vitro translation. However, this method can be adapted for use with other types of fusion proteins; for example, His6, biotin tags, or maltose-binding protein fusions (MBP), and these may offer particular advantages. A describes preparation of an E. coli extract that is added to the reaction mixture with purified test protein to reduce nonspecific binding. PMID:18265191
Craniomandibular morphology and phylogenetic affinities of panthera atrox
Christiansen, Per; Harris, J.M.
2009-01-01
The great North American Pleistocene pantherine felid Panthera atrox has had a turbulent phylogenetic history, and has been claimed to show affinities to both the jaguar and the tiger; currently, it is most often regarded as a subspecies of the extant lion. The cranial, mandibular, and dental...... morphology of Panthera atrox was compared with those of extant lions, jaguars, and tigers using bivariate, multivariate, and shape analyses. Results indicate that the skull of Panthera atrox shows lion affinities, but also deviates from lions in numerous aspects. Mandibular morphology is more similar to...... jaguars and tigers and, as with cranial morphology, the mandible shows a number of traits not present among extant pantherines. Multivariate analyses grouped Panthera atrox separately from other pantherines. Panthera atrox was no lion, and cannot be assigned to any of the extant pantherines; it...
Theoretical Estimate of Hydride Affinities of Aromatic Carbonyl Compounds
AI Teng; ZHU Xiao-Qing; CHENG Jin-Pei
2003-01-01
@@ Aromatic carbonyl compounds are one type of the most important organic compounds, and the reductions ofthem by hydride agents such as LiAlH4 or NaBH4 are widely used in organic synthesis. The reactivity of carbonyl compounds generally increases in the following order: ketone ＜ aldehyde, and amide ＜ acid ＜ ester ＜ acid halide, which could be related to their hydride affinities (HA). In the previous paper, Robert[1] calculated the absolute HAof a series of small non-aromatic carbonyl compounds. In this paper, we use DFT method at B3LYP/6-311 + + G (2d, 2p)∥B3LYP/6-31 + G* level to estimate hydride affinities of five groups of aromatic carbonyl compounds. The detailed results are listed in Table 1.
Nonspectrality of Certain Self-Affine Measures on ℝ3
Gui-Bao Gao
2014-01-01
Full Text Available We will determine the nonspectrality of self-affine measure μB,D corresponding to B=diag[p1,p2,p3] (p1∈(2ℤ+1∖{±1}, p2∈2ℤ∖{0}, and D={0,e1,e2,e3} in the space ℝ3 is supported on T(B,D, where e1, e2, and e3 are the standard basis of unit column vectors in ℝ3, and there exist at most 4 mutually orthogonal exponential functions in L2(μB,D, where the number 4 is the best. This generalizes the known results on the spectrality of self-affine measures.
Black Hole Singularity and Generalized Quantum Affine Parameter
Hosoya, Akio; Oda, Ichiro
1996-01-01
We study a behavior of quantum generalized affine parameter (QGAP), which has been recently proposed by one of the present authors, near the singularity and the event horizon in three and four spacetime dimensions in terms of a minisuperspace model of quantum gravity. It is shown that the QGAP is infinite to the singularity while it remains finite to the event horizon. This fact indicates a possible interpretation that the singularity is wiped out in quantum gravity in this particular model o...
Affinity chromatography based on a combinatorial strategy for rerythropoietin purification.
Martínez-Ceron, María C; Marani, Mariela M; Taulés, Marta; Etcheverrigaray, Marina; Albericio, Fernando; Cascone, Osvaldo; Camperi, Silvia A
2011-05-01
Small peptides containing fewer than 10 amino acids are promising ligand candidates with which to build affinity chromatographic systems for industrial protein purification. The application of combinatorial peptide synthesis strategies greatly facilitates the discovery of suitable ligands for any given protein of interest. Here we sought to identify peptide ligands with affinity for recombinant human erythropoietin (rhEPO), which is used for the treatment of anemia. A combinatorial library containing the octapeptides X-X-X-Phe-X-X-Ala-Gly, where X = Ala, Asp, Glu, Phe, His, Leu, Asn, Pro, Ser, or Thr, was synthesized on HMBA-ChemMatrix resin by the divide-couple-recombine method. For the library screening, rhEPO was coupled to either Texas Red or biotin. Fluorescent beads or beads showing a positive reaction with streptavidin-peroxidase were isolated. After cleavage, peptides were sequenced by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Fifty-seven beads showed a positive reaction. Peptides showing more consensuses were synthesized, and their affinity to rhEPO was assessed using a plasma resonance biosensor. Dissociation constant values in the range of 1-18 μM were obtained. The best two peptides were immobilized on Sepharose, and the resultant chromatographic matrixes showed affinity for rhEPO with dissociation constant values between 1.8 and 2.7 μM. Chinese hamster ovary (CHO) cell culture supernatant was spiked with rhEPO, and the artificial mixture was loaded on Peptide-Sepharose columns. The rhEPO was recovered in the elution fraction with a yield of 90% and a purity of 95% and 97% for P1-Sepharose and P2-Sepharose, respectively. PMID:21495625
Symbolic Dynamics for a Piecewise-Affine System with Hysteresis
Sella, Lorenzo; Collins, Pieter
2008-01-01
In this paper we present the computation of symbolic dynamics of a one dimensional return map of a piecewise-affine hybrid system. The system arises as a simple electrical circuit with hysteresis switching, and exhibits chaotic dynamics. Our method allows us to rigorously obtain a qualitative description of the discrete behaviour of the system. We show how the discrete dynamics changes as a parameter is varied, and we compute bounds for the topological entropy to provide a measure of the comp...
PREPARATION OF CHITOSAN COATED METAL AFFINITY CHROMATOGRAPHY ADSORBENT
AanTianwei; XuWeijiang; 等
1998-01-01
A new and an inexpensive adsorbent of chitosan coated silica for immobilized metal affinity chromatography(IMAC) was studied.After a double coating,the chitosan coated on silica beads could be up to 53.4mg/g silica beads.When pH>3.8,the metal ligand Cu2+ was chelated on the coated chitosan with a bound capacity of 14.6mg/g chitosan without introducing iminodiacetic acid(IDA).
Chitinolytic activity of the rumen ciliates Diploplastron affine
Belzecki, G.; Miltko, R.; Michalowski, T.; Šimůnek, Jiří; Kopečný, Jan
2008-01-01
Roč. 53, č. 3 (2008), s. 201-203. ISSN 0015-5632 R&D Projects: GA ČR GA525/05/2584 Grant ostatní: Ministry of Scientific Research and Information Technology Poland(PL) 2 P06Z 052 30 Institutional research plan: CEZ:AV0Z50450515 Keywords : Diploplastron affine Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008
Affine Correlation Method for Direct Vorticity, Skew and Displacement Estimation
Gronát, Petr
Praha : Ústav termomechaniky, AV ČR, v. v. i., 2010 - (Příhoda, J.; Kozel, K.), s. 59-62 ISBN 978-80-87012-25-3. [Topical Problems of Fluid Mechanics 2010. Praha (CZ), 10.02.2010-11.02.2010] R&D Projects: GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : normalized cross correlation * affine correlation Subject RIV: BK - Fluid Dynamics
Proton Affinities of Organocatalysts Derived from Pyridine N-oxide
Váňa, J.; Roithová, J.; Kotora, Martin; Beran, Pavel; Rulíšek, Lubomír; Kočovský, Pavel
2014-01-01
Roč. 87, č. 4 (2014), s. 349-356. ISSN 0011-1643 R&D Projects: GA ČR(CZ) GA14-31419S Grant ostatní: GA ČR(CZ) GAP207/11/0587 Institutional support: RVO:61388963 Keywords : density functional theory * isodesmic reactions * kinetic method * mass spectrometry * organocatalysis * proton affinity * superbases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.728, year: 2014
Communication: Revised electron affinity of SF6 from kinetic data.
Troe, J.; Miller, T; Viggiano, A.
2012-01-01
Previously determined experimental data for thermal attachment of electrons to SF 6 and thermal detachment from SF 6 − over the range 590–670 K are reevaluated by a third-law analysis. Recent high precision calculations of SF 6 − harmonic frequences and anharmonicities (for several of the modes) lead to considerable changes in modeled vibrational partition functions which then have to be accommodated for by a smaller value of the derived adiabatic electron affinity EA of SF 6 . The previously...
An Early Cambrian problematic fossil: Vetustovermis and its possible affinities
Chen, Jun-Yuan; Huang, Di-Ying; Bottjer, David J.
2005-01-01
The Early Cambrian problematic fossil Vetustovermis (Glaessner 1979 Alcheringa 3, 21–31) was described as an annelid or arthropod. Anatomical analysis of 17 new specimens from the Lower Cambrian Maotianshan Shale at Anning, Kunming (South China) does not support its affinities with annelids or arthropods. Anatomical features instead resemble other animal groups including modern flatworms, nemertines and molluscs. The presence of a pelagic slug-like form and ventral foot, as well as a head wit...
Agonist binding to high-affinity dopamine sites
Tedesco, J.L.
1985-01-01
The authors have characterized the dopamine D/sub 3/ site and its binding requirements. The dopamine D/sub 3/ site in calf caudate crude homogenate has a site density of 214-230 fmoles/mg. protein by both /sup 3/H-apomorphine (/sup 3/H-AOP) and /sup 3/H-dopamine (/sup 3/H-DA) Scatchard analysis of specific binding (SB). Stereospecific subsets of /sup 3/H-APO and /sup 3/H-DA sites were defined by the use of agonist and antagonist enantiomer-pairs as a rigorous test for D/sub 3/ site heterogeneity. IC/sub 50/ values for both /sup 3/H-APO and /sup 3/H-DA SB sites were assessed for 55 agonist ligands and an excellent correlation was obtained. The authors conclude that both /sup 3/H-ligands label the same D/sub 3/ site. The D/sub 3/ site affinities of 105 dopamine-agonist ligands, in particular 2-aminotetralins,, aporphines and flexible dopamine analogues were measured. Low D/sub 3/-site affinities of N-quaternary analogues confirm the need for a lone pair. Subadditivity of substituents' effects in semi-flexible DA analogues confirms their postulate that sidechain conformation is the critical determinant of affinity. They conclude that there are at least two high-affinity ligand conformations of the DA sidechain pharmacophore. These binding requirements are presented as two interface-Geometry tetrahedral models of the double H-bond interface between the D/sub 3/ site and the ideal ligand.
Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin
Renata Angeli; da Paz, Nathalia V. N.; Maciel, Jackeline C.; Flávia F. B. Araújo; Paiva, Patrícia M. G.; Glícia M. T. Calazans; Ana Paula Valente; Almeida, Fábio C. L.; Coelho, Luana C. B. B.; Carvalho, Luiz B; Silva, Maria da Paz C.; Maria Tereza dos Santos Correia
2009-01-01
A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammon...
Families of Dirac operators and quantum affine groups
Mickelsson, Jouko
2010-01-01
Twisted K-theory classes over compact Lie groups can be realized as families of Fredholm operators using the representation theory of loop groups. In this talk I want to show how to deform the Fredholm family, in the sense of quantum groups. The family of Dirac type operators is parametrized by vectors in the adjoint module for a quantum affine algebra and transform covariantly under a (central extension of) the algebra.
Macro factors and the affine term structure of interest rates
Tao Wu
2001-01-01
I formulate an affine term structure model of bond yields from a general equilibrium business-cycle model, with observable macro state variables of the structural economy as the factors. The factor representing monetary policy is strongly mean-reverting, and its influence on the term structure is primarily through changing the slope of the yield curve. The factor representing technology is more persistent, and it affects the term structure by shifting the level of the yield curve. The dynamic...
The relation of morphology and affinity maturation in germinal centers
Meyer-Hermann, M
2002-01-01
The specific morphology of germinal centers is analyzed in the context of the optimization of the humoral immune response. The relevance of dark and light zones for the affinity maturation process is investigated in the framework of a theoretical model for the germinal center reaction. Especially, it is shown that an intermediate appearance of dark zones in germinal center reactions is advantageous for the process of antibody optimization.
Affinity purification of polysaccharide degrading enzymes with crosslinked substrates.
Rozie, H.J.
1992-01-01
The aim of this work was to find economically favourable, affinity based, purification methods for several polysaccharide splitting bulk enzymes. The framework in which this study is done is described in Chapter 1.Chapter 2 describes the adsorption of endo-polygalacturonase (endoPG) from a commercial enzyme preparation (Rapidase) to calcium alginate beads. Approximately 75% of the various polygalacturonase activities from Rapidase can be adsorbed at pH 4.4 by calcium alginate beads as well as...
Term premia and interest rate forecasts in affine models
Duffee, Gregory R.
2000-01-01
I find that the standard class of affine models produces poor forecasts of future changes in Treasury yields. Better forecasts are generated by assuming that yields follow random walks. The failure of these models is driven by one of their key features: the compensation that investors receive for facing risk is a multiple of the variance of the risk. This means that risk compensation cannot vary independently of interest rate volatility. I also describe and empirically estimate a class of mod...
Responding Bodies and Partial Affinities in Human–Animal Worlds
Despret, Vinciane
2013-01-01
The aim of this paper is to explore the different manners in which scientists’ bodies are actively engaged when interacting with the animals they observe in the field. Bodies are multiple, as are the practices that involve them: sharing the same diet, feeling similar affects, acting the same, inhabiting the same world of perceptions, constructing empathic affinities, etc. Some scientists aim to embody the animals’ experiences. Some are willing to empathetically experience situations “from ins...
TALMRS: Time-Affinity Linked Medical Record System
Langer, Robert D.
1987-01-01
Use of relational data base techniques allows the development of a three dimensional medical record system in which data relevant to multiple problems need only be entered once, but may be presented in an essentially unlimited number of contexts. This Time-Affinity Linked Medical Record System (TALMRS) builds upon and extends the concepts of the Problem Oriented Medical Record (POMR). Links which enable the user to view the data in many different ways make it possible for the same record to b...
Affine extensions of functions with a closed graph
Marek Wójtowicz; Waldemar Sieg
2015-01-01
Let \\(A\\) be a closed \\(G_{\\delta}\\)-subset of a normal space \\(X\\). We prove that every function \\(f_0: A\\to\\mathbb{R}\\) with a closed graph can be extended to a function \\(f: X\\to\\mathbb{R}\\) with a closed graph, too. This is a consequence of a more general result which gives an affine and constructive method of obtaining such extensions.
Affine-Detection Loophole in Quantum Data Processing
Vlasov, Alexander Yu.
2002-01-01
Here is considered a specific detection loophole, that is relevant not only to testing of quantum nonlocality, but also to some other applications of quantum computations and communications. It is described by a simple affine relation between different quantum "data structures" like pure and mixed state, separable and inseparable one. It is shown also, that due to such relations imperfect device for a classical model may mimic measurements of quantum correlations on ideal equipment.
Identification and Estimation of Gaussian Affine Term Structure Models
Hamilton, James D.; Jing Cynthia Wu
2012-01-01
This paper develops new results for identification and estimation of Gaussian affine term structure models. We establish that three popular canonical representations are unidentified, and demonstrate how unidentified regions can complicate numerical optimization. A separate contribution of the paper is the proposal of minimum-chi-square estimation as an alternative to MLE. We show that, although it is asymptotically equivalent to MLE, it can be much easier to compute. In some cases, MCSE allo...
A pulse radiolysis study on electron affinity of piperonal
MA; Jianhua; LIN; Weizhen; WANG; Wenfeng; YAO; Side
2005-01-01
The piperonal electron affinity was studied using pulse radiolysis technique. The electron transfer reaction process between piperonal and anthraquinone-2-sulfate was observed in the pH 7 phosphoric acid salt buffer. The transient absorption spectra of electron transfer reaction between piperonal and anthraquinone-2-sulfate were obtained, and the initial proof of the electron transfer between electron donor and acceptor was provided directly. The one-electron reduction potential of piperonal was determined to be -0.457 V.
Affitins for protein purification by affinity magnetic fishing.
Fernandes, Cláudia S M; Dos Santos, Raquel; Ottengy, Stella; Viecinski, Aline Canani; Béhar, Ghislaine; Mouratou, Barbara; Pecorari, Frédéric; Roque, A Cecília A
2016-07-29
Currently most economical and technological bottlenecks in protein production are placed in the downstream processes. With the aim of increasing the efficiency and reducing the associated costs, various affinity ligands have been developed. Affitins are small, yet robust and easy to produce, proteins derived from the archaeal extremophilic "7kDa DNA-binding" protein family. By means of combinatorial protein engineering and ribosome display selection techniques, Affitins have shown to bind a diversity of targets. In this work, two previously developed Affitins (anti-lysozyme and anti-IgG) were immobilized onto magnetic particles to assess their potential for protein purification by magnetic fishing. The optimal lysozyme and human IgG binding conditions yielded 58mg lysozyme/g support and 165mgIgG/g support, respectively. The recovery of proteins was possible in high yield (≥95%) and with high purity, namely ≥95% and 81%, when recovering lysozyme from Escherichia coli supernatant and IgG from human plasma, respectively. Static binding studies indicated affinity constants of 5.0×10(4)M(-1) and 9.3×10(5)M(-1) for the anti-lysozyme and anti-IgG magnetic supports. This work demonstrated that Affitins, which can be virtually evolved for any protein of interest, can be coupled onto magnetic particles creating novel affinity adsorbents for purification by magnetic fishing. PMID:27342136
Supramolecular Affinity Chromatography for Methylation-Targeted Proteomics.
Garnett, Graham A E; Starke, Melissa J; Shaurya, Alok; Li, Janessa; Hof, Fraser
2016-04-01
Proteome-wide studies of post-translationally methylated species using mass spectrometry are complicated by high sample diversity, competition for ionization among peptides, and mass redundancies. Antibody-based enrichment has powered methylation proteomics until now, but the reliability, pan-specificity, polyclonal nature, and stability of the available pan-specific antibodies are problematic and do not provide a standard, reliable platform for investigators. We have invented an anionic supramolecular host that can form host-guest complexes selectively with methyllysine-containing peptides and used it to create a methylysine-affinity column. The column resolves peptides on the basis of methylation-a feat impossible with a comparable commercial cation-exchange column. A proteolyzed nuclear extract was separated on the methyl-affinity column prior to standard proteomics analysis. This experiment demonstrates that such chemical methyl-affinity columns are capable of enriching and improving the analysis of methyllysine residues from complex protein mixtures. We discuss the importance of this advance in the context of biomolecule-driven enrichment methods. PMID:26973166