Science.gov

Sample records for mutually unbiased bases

  1. Mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Chaturvedi, S.

    2002-08-01

    After a brief review of the notion of a full set of mutually unbiased bases in an N-dimensional Hilbert space, we summarize the work of Wootters and Fields (W K Wootters and B C Fields, Ann. Phys. 191, 363 (1989)) which gives an explicit construction for such bases for the case N=pr, where p is a prime. Further, we show how, by exploiting certain freedom in the Wootters-Fields construction, the task of explicitly writing down such bases can be simplified for the case when p is an odd prime. In particular, we express the results entirely in terms of the character vectors of the cyclic group G of order p. We also analyse the connection between mutually unbiased bases and the representations of G.

  2. Covariant mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Carmeli, Claudio; Schultz, Jussi; Toigo, Alessandro

    2016-06-01

    The connection between maximal sets of mutually unbiased bases (MUBs) in a prime-power dimensional Hilbert space and finite phase-space geometries is well known. In this article, we classify MUBs according to their degree of covariance with respect to the natural symmetries of a finite phase-space, which are the group of its affine symplectic transformations. We prove that there exist maximal sets of MUBs that are covariant with respect to the full group only in odd prime-power dimensional spaces, and in this case, their equivalence class is actually unique. Despite this limitation, we show that in dimension 2r covariance can still be achieved by restricting to proper subgroups of the symplectic group, that constitute the finite analogues of the oscillator group. For these subgroups, we explicitly construct the unitary operators yielding the covariance.

  3. Entanglement in Mutually Unbiased Bases

    NASA Astrophysics Data System (ADS)

    Wiesniak, Marcin; Paterek, Tomasz; Zeilinger, Anton

    2011-03-01

    Higher-dimensional Hilbert spaces are still not fully explored. One issue concerns mutually unbiased bases (MUBs). For primes and their powers (e.g.), full sets of MUBs are known. The question of existence of all MUBs in composite dimensions is still open. We show that for all full sets of MUBs of a given dimension a certain entanglement measure of the bases is constant. This fact could be an argument either for or against the existence of full sets of MUBs in some dimensions and tells us that almost all MUBs are maximally entangled for high-dimensional composite systems, whereas this is not the case for prime dimensions. We present a new construction of MUBs in squared prime dimensions. We use only one entangling operation, which simplifies possible experiments. The construction gives only product states and maximally entangled states. Research supported by ERC Advanced Grant QIT4QAD and FWF SFB-grant F4007 of the Austrian Science Fund.

  4. Arithmetic, mutually unbiased bases and complementary observables

    NASA Astrophysics Data System (ADS)

    Sheppeard, M. D.

    2010-02-01

    Complementary observables in quantum mechanics may be viewed as Frobenius structures in a dagger monoidal category, such as the category of finite dimensional Hilbert spaces over the complex numbers. On the other hand, their properties crucially depend on the discrete Fourier transform and its associated quantum torus, requiring only the finite fields that underlie mutually unbiased bases. In axiomatic topos theory, the complex numbers are difficult to describe and should not be invoked unnecessarily. This paper surveys some fundamentals of quantum arithmetic using finite field complementary observables, with a view considering more general axiom systems.

  5. Mutually unbiased bases and bound entanglement

    NASA Astrophysics Data System (ADS)

    Hiesmayr, Beatrix C.; Löffler, Wolfgang

    2014-04-01

    In this contribution we relate two different key concepts: mutually unbiased bases (MUBs) and entanglement. We provide a general toolbox for analyzing and comparing entanglement of quantum states for different dimensions and numbers of particles. In particular we focus on bound entanglement, i.e. highly mixed states which cannot be distilled by local operations and classical communications. For a certain class of states—for which the state-space forms a ‘magic’ simplex—we analyze the set of bound entangled states detected by the MUB criterion for different dimensions d and number of particles n. We find that the geometry is similar for different d and n, consequently the MUB criterion opens possibilities to investigate the typicality of positivity under partial transposition (PPT)-bound and multipartite bound entanglement more deeply and provides a simple experimentally feasible tool to detect bound entanglement.

  6. Quantum process reconstruction based on mutually unbiased basis

    NASA Astrophysics Data System (ADS)

    Fernández-Pérez, A.; Klimov, A. B.; Saavedra, C.

    2011-05-01

    We study a quantum process reconstruction based on the use of mutually unbiased projectors (MUB projectors) as input states for a D-dimensional quantum system, with D being a power of a prime number. This approach connects the results of quantum-state tomography using mutually unbiased bases with the coefficients of a quantum process, expanded in terms of MUB projectors. We also study the performance of the reconstruction scheme against random errors when measuring probabilities at the MUB projectors.

  7. Graph-state formalism for mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Spengler, Christoph; Kraus, Barbara

    2013-11-01

    A pair of orthonormal bases is called mutually unbiased if all mutual overlaps between any element of one basis and an arbitrary element of the other basis coincide. In case the dimension, d, of the considered Hilbert space is a power of a prime number, complete sets of d+1 mutually unbiased bases (MUBs) exist. Here we present a method based on the graph-state formalism to construct such sets of MUBs. We show that for n p-level systems, with p being prime, one particular graph suffices to easily construct a set of pn+1 MUBs. In fact, we show that a single n-dimensional vector, which is associated with this graph, can be used to generate a complete set of MUBs and demonstrate that this vector can be easily determined. Finally, we discuss some advantages of our formalism regarding the analysis of entanglement structures in MUBs, as well as experimental realizations.

  8. Detecting entanglement of continuous variables with three mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Paul, E. C.; Tasca, D. S.; Rudnicki, Łukasz; Walborn, S. P.

    2016-07-01

    An uncertainty relation is introduced for a symmetric arrangement of three mutually unbiased bases in continuous-variable phase space, and then used to derive a bipartite entanglement criterion based on the variance of global operators composed of these three phase-space variables. We test this criterion using spatial variables of photon pairs and show that the entangled photons are correlated in three pairs of bases.

  9. An analytic function approach to weak mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Olupitan, T.; Lei, C.; Vourdas, A.

    2016-08-01

    Quantum systems with variables in Z(d) are considered, and three different structures are studied. The first is weak mutually unbiased bases, for which the absolute value of the overlap of any two vectors in two different bases is 1 /√{ k } (where k | d) or 0. The second is maximal lines through the origin in the Z(d) × Z(d) phase space. The third is an analytic representation in the complex plane based on Theta functions, and their zeros. It is shown that there is a correspondence (triality) that links strongly these three apparently different structures. For simplicity, the case where d =p1 ×p2, where p1 ,p2 are odd prime numbers different from each other, is considered.

  10. Galois-unitary operators that cycle mutually-unbiased bases

    NASA Astrophysics Data System (ADS)

    Dang, Hoan; Appleby, Marcus; Bengtsson, Ingemar

    2015-03-01

    Wigner's theorem states that probability-preserving transformations of quantum states must be either unitary or anti-unitary. However, if we restrict ourselves to a subspace of a Hilbert space, it is possible to generalize the notion of anti-unitaries. Such transformations were recently constructed in search of Symmetric Informationally-Complete (SIC) states. They are called Galois-unitaries (g-unitaries for short), as they are unitaries composed with Galois automorphisms of a chosen number field extension. Despite certain bizarre behaviors of theirs, we show that g-unitaries are indeed useful in the theory of Mutually-Unbiased Bases (MUBs), as they help solve the MUB-cycling problem and provide a construction of MUB-balanced states. HD was supported by the Natural Sciences and Engineering Research Council of Canada and the Vanier Canada Graduate Scholarship

  11. Mutually unbiased bases as minimal Clifford covariant 2-designs

    NASA Astrophysics Data System (ADS)

    Zhu, Huangjun

    2015-06-01

    Mutually unbiased bases (MUBs) are interesting for various reasons. The most attractive example of (a complete set of) MUBs is the one constructed by Ivanović as well as Wootters and Fields, which is referred to as the canonical MUB. Nevertheless, little is known about anything that is unique to this MUB. We show that the canonical MUB in any prime power dimension is uniquely determined by an extremal orbit of the (restricted) Clifford group except in dimension 3, in which case the orbit defines a special symmetric informationally complete measurement (SIC), known as the Hesse SIC. Here the extremal orbit is the orbit with the smallest number of pure states. Quite surprisingly, this characterization does not rely on any concept that is related to bases or unbiasedness. As a corollary, the canonical MUB is the unique minimal 2-design covariant with respect to the Clifford group except in dimension 3. In addition, these MUBs provide an infinite family of highly symmetric frames and positive-operator-valued measures (POVMs), which are of independent interest.

  12. Mutually unbiased bases in six dimensions: The four most distant bases

    SciTech Connect

    Raynal, Philippe; Lue Xin; Englert, Berthold-Georg

    2011-06-15

    We consider the average distance between four bases in six dimensions. The distance between two orthonormal bases vanishes when the bases are the same, and the distance reaches its maximal value of unity when the bases are unbiased. We perform a numerical search for the maximum average distance and find it to be strictly smaller than unity. This is strong evidence that no four mutually unbiased bases exist in six dimensions. We also provide a two-parameter family of three bases which, together with the canonical basis, reach the numerically found maximum of the average distance, and we conduct a detailed study of the structure of the extremal set of bases.

  13. Higher-dimensional orbital-angular-momentum-based quantum key distribution with mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Mafu, Mhlambululi; Dudley, Angela; Goyal, Sandeep; Giovannini, Daniel; McLaren, Melanie; Padgett, Miles J.; Konrad, Thomas; Petruccione, Francesco; Lütkenhaus, Norbert; Forbes, Andrew

    2013-09-01

    We present an experimental study of higher-dimensional quantum key distribution protocols based on mutually unbiased bases, implemented by means of photons carrying orbital angular momentum. We perform (d+1) mutually unbiased measurements in a classically simulated prepare-and-measure scheme and on a pair of entangled photons for dimensions ranging from d=2 to 5. In our analysis, we pay attention to the detection efficiency and photon pair creation probability. As security measures, we determine from experimental data the average error rate, the mutual information shared between the sender and receiver, and the secret key generation rate per photon. We demonstrate that increasing the dimension leads to an increased information capacity as well as higher key generation rates per photon. However, we find that the benefit of increasing the dimension is limited by practical implementation considerations, which in our case results in deleterious effects observed beyond a dimension of d=4.

  14. There is no generalization of known formulas for mutually unbiased bases

    NASA Astrophysics Data System (ADS)

    Archer, Claude

    2005-02-01

    In a quantum system having a finite number N of orthogonal states, two orthonormal bases {ai} and {bj} are called mutually unbiased if all inner products ⟨ai∣bj⟩ have the same modulus 1/√N . This concept appears in several quantum information problems. The number of pairwise mutually unbiased bases is at most N +1 and various constructions of such N +1 bases have been found when N is a power of a prime number. We study families of formulas that generalize these constructions to arbitrary dimensions using finite rings. We then prove that there exists a set of N +1 mutually unbiased bases described by such formulas, if and only if N is a power of a prime number.

  15. Test of mutually unbiased bases for six-dimensional photonic quantum systems

    PubMed Central

    D'Ambrosio, Vincenzo; Cardano, Filippo; Karimi, Ebrahim; Nagali, Eleonora; Santamato, Enrico; Marrucci, Lorenzo; Sciarrino, Fabio

    2013-01-01

    In quantum information, complementarity of quantum mechanical observables plays a key role. The eigenstates of two complementary observables form a pair of mutually unbiased bases (MUBs). More generally, a set of MUBs consists of bases that are all pairwise unbiased. Except for specific dimensions of the Hilbert space, the maximal sets of MUBs are unknown in general. Even for a dimension as low as six, the identification of a maximal set of MUBs remains an open problem, although there is strong numerical evidence that no more than three simultaneous MUBs do exist. Here, by exploiting a newly developed holographic technique, we implement and test different sets of three MUBs for a single photon six-dimensional quantum state (a “qusix”), encoded exploiting polarization and orbital angular momentum of photons. A close agreement is observed between theory and experiments. Our results can find applications in state tomography, quantitative wave-particle duality, quantum key distribution. PMID:24067548

  16. Discrete phase-space structure of n-qubit mutually unbiased bases

    SciTech Connect

    Klimov, A.B.; Romero, J.L.; Bjoerk, G.; Sanchez-Soto, L.L.

    2009-01-15

    We work out the phase-space structure for a system of n qubits. We replace the field of real numbers that label the axes of the continuous phase space by the finite field GF(2{sup n}) and investigate the geometrical structures compatible with the notion of unbiasedness. These consist of bundles of discrete curves intersecting only at the origin and satisfying certain additional properties. We provide a simple classification of such curves and study in detail the four- and eight-dimensional cases, analyzing also the effect of local transformations. In this way, we provide a comprehensive phase-space approach to the construction of mutually unbiased bases for n qubits.

  17. Temporal steering and security of quantum key distribution with mutually unbiased bases against individual attacks

    NASA Astrophysics Data System (ADS)

    Bartkiewicz, Karol; Černoch, Antonín; Lemr, Karel; Miranowicz, Adam; Nori, Franco

    2016-06-01

    Temporal steering, which is a temporal analog of Einstein-Podolsky-Rosen steering, refers to temporal quantum correlations between the initial and final state of a quantum system. Our analysis of temporal steering inequalities in relation to the average quantum bit error rates reveals the interplay between temporal steering and quantum cloning, which guarantees the security of quantum key distribution based on mutually unbiased bases against individual attacks. The key distributions analyzed here include the Bennett-Brassard 1984 protocol and the six-state 1998 protocol by Bruss. Moreover, we define a temporal steerable weight, which enables us to identify a kind of monogamy of temporal correlation that is essential to quantum cryptography and useful for analyzing various scenarios of quantum causality.

  18. Nonexistence of sharply covariant mutually unbiased bases in odd prime dimensions

    NASA Astrophysics Data System (ADS)

    Zhu, Huangjun

    2015-09-01

    Mutually unbiased bases (MUB) are useful in a number of research areas. The symmetry of MUB is an elusive and interesting subject. A (complete set of) MUB in dimension d is sharply covariant if it can be generated by a group of order d (d +1 ) from a basis state. Such MUB, if they exist, would be most appealing to theoretical studies and practical applications. Unfortunately, they seem to be quite rare. Here we prove that no MUB in odd prime dimensions is sharply covariant, by virtue of clever applications of Mersenne primes, Galois fields, and Frobenius groups. This conclusion provides valuable insight about the symmetry of MUB and the geometry of quantum state space. It complements and strengthens the earlier result of the author that only two stabilizer MUB are sharply covariant. Our study leads to the conjecture that no MUB other than those in dimensions 2 and 4 is sharply covariant.

  19. Bipartite entangled stabilizer mutually unbiased bases as maximum cliques of Cayley graphs

    SciTech Connect

    Dam, Wim van; Howard, Mark

    2011-07-15

    We examine the existence and structure of particular sets of mutually unbiased bases (MUBs) in bipartite qudit systems. In contrast to well-known power-of-prime MUB constructions, we restrict ourselves to using maximally entangled stabilizer states as MUB vectors. Consequently, these bipartite entangled stabilizer MUBs (BES MUBs) provide no local information, but are sufficient and minimal for decomposing a wide variety of interesting operators including (mixtures of) Jamiolkowski states, entanglement witnesses, and more. The problem of finding such BES MUBs can be mapped, in a natural way, to that of finding maximum cliques in a family of Cayley graphs. Some relationships with known power-of-prime MUB constructions are discussed, and observables for BES MUBs are given explicitly in terms of Pauli operators.

  20. Reply to ''Comment on 'Mutually unbiased bases, orthogonal Latin squares, and hidden-variable models'''

    SciTech Connect

    Paterek, Tomasz; Dakic, Borivoje; Brukner, Caslav

    2011-03-15

    In this Reply to the preceding Comment by Hall and Rao [Phys. Rev. A 83, 036101 (2011)], we motivate terminology of our original paper and point out that further research is needed in order to (dis)prove the claimed link between every orthogonal Latin square of order being a power of a prime and a mutually unbiased basis.

  1. Block-circulant matrices with circulant blocks, Weil sums, and mutually unbiased bases. II. The prime power case

    NASA Astrophysics Data System (ADS)

    Combescure, Monique

    2009-03-01

    In our previous paper [Combescure, M., "Circulant matrices, Gauss sums and the mutually unbiased bases. I. The prime number case," Cubo A Mathematical Journal (unpublished)] we have shown that the theory of circulant matrices allows to recover the result that there exists p +1 mutually unbiased bases in dimension p, p being an arbitrary prime number. Two orthonormal bases B, B' of Cd are said mutually unbiased if ∀bɛB, ∀b'ɛB' one has that |b ṡb'|=1/√d (b ṡb' Hermitian scalar product in Cd). In this paper we show that the theory of block-circulant matrices with circulant blocks allows to show very simply the known result that if d =pn (p a prime number and n any integer) there exists d +1 mutually unbiased bases in Cd. Our result relies heavily on an idea of Klimov et al. ["Geometrical approach to the discrete Wigner function," J. Phys. A 39, 14471 (2006)]. As a subproduct we recover properties of quadratic Weil sums for p ≥3, which generalizes the fact that in the prime case the quadratic Gauss sum properties follow from our results.

  2. FAST TRACK COMMUNICATION: Affine constellations without mutually unbiased counterparts

    NASA Astrophysics Data System (ADS)

    Weigert, Stefan; Durt, Thomas

    2010-10-01

    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. The observed discrepancies make a deeper relation between the two existence problems unlikely.

  3. Separability criteria via sets of mutually unbiased measurements

    PubMed Central

    Liu, Lu; Gao, Ting; Yan, Fengli

    2015-01-01

    Mutually unbiased measurements (MUMs) are generalized from the concept of mutually unbiased bases (MUBs) and include the complete set of MUBs as a special case, but they are superior to MUBs as they do not need to be rank one projectors. We investigate entanglement detection using sets of MUMs and derive separability criteria for multipartite qudit systems, arbitrary high-dimensional bipartite systems of a d1-dimensional subsystem and a d2-dimensional subsystem, and multipartite systems of multi-level subsystems. These criteria are of the advantages of more effective and wider application range than previous criteria. They provide experimental implementation in detecting entanglement of unknown quantum states. PMID:26278628

  4. Entanglement patterns in mutually unbiased basis sets

    SciTech Connect

    Lawrence, Jay

    2011-08-15

    A few simply stated rules govern the entanglement patterns that can occur in mutually unbiased basis sets (MUBs) and constrain the combinations of such patterns that can coexist in full complements of MUBs. We consider Hilbert spaces of prime power dimensions (D=p{sup N}), as realized by systems of N prime-state particles, where full complements of D+1 MUBs are known to exist, and we assume only that MUBs are eigenbases of generalized Pauli operators, without using any particular construction. The general rules include the following: (1) In any MUB, a given particle appears either in a pure state or totally entangled and (2) in any full MUB complement, each particle is pure in (p+1) bases (not necessarily the same ones) and totally entangled in the remaining (p{sup N}-p). It follows that the maximum number of product bases is p+1 and, when this number is realized, all remaining (p{sup N}-p) bases in the complement are characterized by the total entanglement of every particle. This ''standard distribution'' is inescapable for two-particle systems (of any p), where only product and generalized Bell bases are admissible MUB types. This and the following results generalize previous results for qubits [Phys. Rev. A 65. 032320 (2002); Phys. Rev. A 72, 062310 (2005)] and qutrits [Phys. Rev. A 70, 012302 (2004)], drawing particularly upon [Phys. Rev. A 72, 062310 (2005)]. With three particles there are three MUB types, and these may be combined in (p+2) different ways to form full complements. With N=4, there are 6 MUB types for p=2, but new MUB types become possible with larger p, and these are essential to realizing full complements. With this example, we argue that new MUB types that show new entanglement patterns should enter with every step in N and, also, when N is a prime plus 1, at a critical p value, p=N-1. Such MUBs should play critical roles in filling complements.

  5. Partially unbiased entangled bases

    NASA Astrophysics Data System (ADS)

    Kalev, A.; Khanna, F. C.; Revzen, M.

    2009-08-01

    In this contribution we group the operator basis for d2 -dimensional Hilbert space in a way that enables us to relate bases of entangled states with single-particle mutually unbiased state bases (MUB), each in dimensionality d . We utilize these sets of operators to show that an arbitrary density matrix for this d2 -dimensional Hilbert-space system is analyzed via d2+d+1 measurements, d2-d of which involve those entangled states that we associate with MUB of the d -dimensional single-particle constituents. The number d2+d+1 lies in the middle of the number of measurements needed for bipartite state reconstruction with two-particle MUB (d2+1) and those needed by single-particle MUB [(d2+1)2] .

  6. Quantum state tomography via mutually unbiased measurements in driven cavity QED systems

    NASA Astrophysics Data System (ADS)

    Yuan, Hao; Zhou, Zheng-Wei; Guo, Guang-Can

    2016-04-01

    We present a feasible proposal for quantum tomography of qubit and qutrit states via mutually unbiased measurements in dispersively coupled driven cavity QED systems. We first show that measurements in the mutually unbiased bases (MUBs) are practically implemented by projecting the detected states onto the computational basis after performing appropriate unitary transformations. The measurement outcomes can then be determined by detecting the steady-state transmission spectra (SSTS) of the driven cavity. It is found that all the measurement outcomes for each MUB (i.e., all the diagonal elements of the density matrix of each detected state) can be read out directly from only one kind of SSTS. In this way, we numerically demonstrate that the exemplified qubit and qutrit states can be reconstructed with the fidelities 0.952 and 0.961, respectively. Our proposal could be straightforwardly extended to other high-dimensional quantum systems provided that their MUBs exist.

  7. TOPICAL REVIEW: An angular momentum approach to quadratic Fourier transform, Hadamard matrices, Gauss sums, mutually unbiased bases, the unitary group and the Pauli group

    NASA Astrophysics Data System (ADS)

    Kibler, Maurice R.

    2009-09-01

    The construction of unitary operator bases in a finite-dimensional Hilbert space is reviewed through a nonstandard approach combining angular momentum theory and representation theory of SU(2). A single formula for the bases is obtained from a polar decomposition of SU(2) and is analyzed in terms of cyclic groups, quadratic Fourier transforms, Hadamard matrices and generalized Gauss sums. Weyl pairs, generalized Pauli operators and their application to the unitary group and the Pauli group naturally arise in this approach. Dedicated to the memory of Yurii Fedorovich Smirnov.

  8. Personalized recommendation based on unbiased consistence

    NASA Astrophysics Data System (ADS)

    Zhu, Xuzhen; Tian, Hui; Zhang, Ping; Hu, Zheng; Zhou, Tao

    2015-08-01

    Recently, in physical dynamics, mass-diffusion-based recommendation algorithms on bipartite network provide an efficient solution by automatically pushing possible relevant items to users according to their past preferences. However, traditional mass-diffusion-based algorithms just focus on unidirectional mass diffusion from objects having been collected to those which should be recommended, resulting in a biased causal similarity estimation and not-so-good performance. In this letter, we argue that in many cases, a user's interests are stable, and thus bidirectional mass diffusion abilities, no matter originated from objects having been collected or from those which should be recommended, should be consistently powerful, showing unbiased consistence. We further propose a consistence-based mass diffusion algorithm via bidirectional diffusion against biased causality, outperforming the state-of-the-art recommendation algorithms in disparate real data sets, including Netflix, MovieLens, Amazon and Rate Your Music.

  9. Mutual information-based facial expression recognition

    NASA Astrophysics Data System (ADS)

    Hazar, Mliki; Hammami, Mohamed; Hanêne, Ben-Abdallah

    2013-12-01

    This paper introduces a novel low-computation discriminative regions representation for expression analysis task. The proposed approach relies on interesting studies in psychology which show that most of the descriptive and responsible regions for facial expression are located around some face parts. The contributions of this work lie in the proposition of new approach which supports automatic facial expression recognition based on automatic regions selection. The regions selection step aims to select the descriptive regions responsible or facial expression and was performed using Mutual Information (MI) technique. For facial feature extraction, we have applied Local Binary Patterns Pattern (LBP) on Gradient image to encode salient micro-patterns of facial expressions. Experimental studies have shown that using discriminative regions provide better results than using the whole face regions whilst reducing features vector dimension.

  10. Mutually Unbiasedness between Maximally Entangled Bases and Unextendible Maximally Entangled Systems in C2⊗ C^{2k}

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Nan, Hua; Tao, Yuan-Hong; Fei, Shao-Ming

    2016-02-01

    The mutually unbiasedness between a maximally entangled basis (MEB) and an unextendible maximally entangled system (UMES) in the bipartite system C2⊗ C^{2k} (k>1) are introduced and discussed first in this paper. Then two mutually unbiased pairs of a maximally entangled basis and an unextendible maximally entangled system are constructed; lastly, explicit constructions are obtained for mutually unbiased MEB and UMES in C2⊗ C4 and C2⊗ C8, respectively.

  11. Spatial Mutual Information Based Hyperspectral Band Selection for Classification

    PubMed Central

    2015-01-01

    The amount of information involved in hyperspectral imaging is large. Hyperspectral band selection is a popular method for reducing dimensionality. Several information based measures such as mutual information have been proposed to reduce information redundancy among spectral bands. Unfortunately, mutual information does not take into account the spatial dependency between adjacent pixels in images thus reducing its robustness as a similarity measure. In this paper, we propose a new band selection method based on spatial mutual information. As validation criteria, a supervised classification method using support vector machine (SVM) is used. Experimental results of the classification of hyperspectral datasets show that the proposed method can achieve more accurate results. PMID:25918742

  12. Problem decomposition by mutual information and force-based clustering

    NASA Astrophysics Data System (ADS)

    Otero, Richard Edward

    The scale of engineering problems has sharply increased over the last twenty years. Larger coupled systems, increasing complexity, and limited resources create a need for methods that automatically decompose problems into manageable sub-problems by discovering and leveraging problem structure. The ability to learn the coupling (inter-dependence) structure and reorganize the original problem could lead to large reductions in the time to analyze complex problems. Such decomposition methods could also provide engineering insight on the fundamental physics driving problem solution. This work forwards the current state of the art in engineering decomposition through the application of techniques originally developed within computer science and information theory. The work describes the current state of automatic problem decomposition in engineering and utilizes several promising ideas to advance the state of the practice. Mutual information is a novel metric for data dependence and works on both continuous and discrete data. Mutual information can measure both the linear and non-linear dependence between variables without the limitations of linear dependence measured through covariance. Mutual information is also able to handle data that does not have derivative information, unlike other metrics that require it. The value of mutual information to engineering design work is demonstrated on a planetary entry problem. This study utilizes a novel tool developed in this work for planetary entry system synthesis. A graphical method, force-based clustering, is used to discover related sub-graph structure as a function of problem structure and links ranked by their mutual information. This method does not require the stochastic use of neural networks and could be used with any link ranking method currently utilized in the field. Application of this method is demonstrated on a large, coupled low-thrust trajectory problem. Mutual information also serves as the basis for an

  13. MR images denoising using DCT-based unbiased nonlocal means filter

    NASA Astrophysics Data System (ADS)

    Zheng, Xiuqing; Hu, Jinrong; Zhou, Jiuliu

    2013-03-01

    The non-local means (NLM) filter has been proven to be an efficient feature-preserved denoising method and can be applied to remove noise in the magnetic resonance (MR) images. To suppress noise more efficiently, we present a novel NLM filter by using a low-pass filtered and low dimensional version of neighborhood for calculating the similarity weights. The discrete cosine transform (DCT) is used as a smoothing kernel, allowing both improvements in similarity estimation and computational speed-up. Experimental results show that the proposed filter achieves better denoising performance in MR Images compared to others filters, such as recently proposed NLM filter and unbiased NLM (UNLM) filter.

  14. Networks in financial markets based on the mutual information rate

    NASA Astrophysics Data System (ADS)

    Fiedor, Paweł

    2014-05-01

    In the last few years there have been many efforts in econophysics studying how network theory can facilitate understanding of complex financial markets. These efforts consist mainly of the study of correlation-based hierarchical networks. This is somewhat surprising as the underlying assumptions of research looking at financial markets are that they are complex systems and thus behave in a nonlinear manner, which is confirmed by numerous studies, making the use of correlations which are inherently dealing with linear dependencies only baffling. In this paper we introduce a way to incorporate nonlinear dynamics and dependencies into hierarchical networks to study financial markets using mutual information and its dynamical extension: the mutual information rate. We show that this approach leads to different results than the correlation-based approach used in most studies, on the basis of 91 companies listed on the New York Stock Exchange 100 between 2003 and 2013, using minimal spanning trees and planar maximally filtered graphs.

  15. Autonomous navigation method based on unbiased minimum-variance estimation during Mars entry

    NASA Astrophysics Data System (ADS)

    Fu, Huimin; Yang, Yusong; Xiao, Qiang; Wu, Yunzhang; Zhang, Yongbo

    2015-03-01

    Accurate navigation systems are required for future pinpoint Mars landing missions. A radio ranging augmented inertial measurement unit (IMU) navigation system concept is considered for the guided atmospheric entry phase. The systematic errors associated to the radio ranging and inertial measurements, and the atmospheric mission uncertainties are considered to be unknown. This paper presents the extension of an unbiased minimum-variance (EUMV) filter of a radio beacon/IMU navigation system. In the presence of unknown dynamics inputs, the filter joins the system state and the unknown systematic error estimation of a stochastic nonlinear time-varying discrete system. 3-DOF simulation results show that the performances of the proposed navigation filter algorithm, 100 m estimated altitude error and 8 m/s estimated velocity error, fulfills the need of future pinpoint Mars landing missions.

  16. Least-bias state estimation with incomplete unbiased measurements

    NASA Astrophysics Data System (ADS)

    Řeháček, Jaroslav; Hradil, Zdeněk; Teo, Yong Siah; Sánchez-Soto, Luis L.; Ng, Hui Khoon; Chai, Jing Hao; Englert, Berthold-Georg

    2015-11-01

    Measuring incomplete sets of mutually unbiased bases constitutes a sensible approach to the tomography of high-dimensional quantum systems. The unbiased nature of these bases optimizes the uncertainty hypervolume. However, imposing unbiasedness on the probabilities for the unmeasured bases does not generally yield the estimator with the largest von Neumann entropy, a popular figure of merit in this context. Furthermore, this imposition typically leads to mock density matrices that are not even positive definite. This provides a strong argument against perfunctory applications of linear estimation strategies. We propose to use instead the physical state estimators that maximize the Shannon entropy of the unmeasured outcomes, which quantifies our lack of knowledge fittingly and gives physically meaningful statistical predictions.

  17. Predicting Genetic Values: A Kernel-Based Best Linear Unbiased Prediction With Genomic Data

    PubMed Central

    Ober, Ulrike; Erbe, Malena; Long, Nanye; Porcu, Emilio; Schlather, Martin; Simianer, Henner

    2011-01-01

    Genomic data provide a valuable source of information for modeling covariance structures, allowing a more accurate prediction of total genetic values (GVs). We apply the kriging concept, originally developed in the geostatistical context for predictions in the low-dimensional space, to the high-dimensional space spanned by genomic single nucleotide polymorphism (SNP) vectors and study its properties in different gene-action scenarios. Two different kriging methods [“universal kriging” (UK) and “simple kriging” (SK)] are presented. As a novelty, we suggest use of the family of Matérn covariance functions to model the covariance structure of SNP vectors. A genomic best linear unbiased prediction (GBLUP) is applied as a reference method. The three approaches are compared in a whole-genome simulation study considering additive, additive-dominance, and epistatic gene-action models. Predictive performance is measured in terms of correlation between true and predicted GVs and average true GVs of the individuals ranked best by prediction. We show that UK outperforms GBLUP in the presence of dominance and epistatic effects. In a limiting case, it is shown that the genomic covariance structure proposed by VanRaden (2008) can be considered as a covariance function with corresponding quadratic variogram. We also prove theoretically that if a specific linear relationship exists between covariance matrices for two linear mixed models, the GVs resulting from BLUP are linked by a scaling factor. Finally, the relation of kriging to other models is discussed and further options for modeling the covariance structure, which might be more appropriate in the genomic context, are suggested. PMID:21515573

  18. MIRA: mutual information-based reporter algorithm for metabolic networks

    PubMed Central

    Cicek, A. Ercument; Roeder, Kathryn; Ozsoyoglu, Gultekin

    2014-01-01

    Motivation: Discovering the transcriptional regulatory architecture of the metabolism has been an important topic to understand the implications of transcriptional fluctuations on metabolism. The reporter algorithm (RA) was proposed to determine the hot spots in metabolic networks, around which transcriptional regulation is focused owing to a disease or a genetic perturbation. Using a z-score-based scoring scheme, RA calculates the average statistical change in the expression levels of genes that are neighbors to a target metabolite in the metabolic network. The RA approach has been used in numerous studies to analyze cellular responses to the downstream genetic changes. In this article, we propose a mutual information-based multivariate reporter algorithm (MIRA) with the goal of eliminating the following problems in detecting reporter metabolites: (i) conventional statistical methods suffer from small sample sizes, (ii) as z-score ranges from minus to plus infinity, calculating average scores can lead to canceling out opposite effects and (iii) analyzing genes one by one, then aggregating results can lead to information loss. MIRA is a multivariate and combinatorial algorithm that calculates the aggregate transcriptional response around a metabolite using mutual information. We show that MIRA’s results are biologically sound, empirically significant and more reliable than RA. Results: We apply MIRA to gene expression analysis of six knockout strains of Escherichia coli and show that MIRA captures the underlying metabolic dynamics of the switch from aerobic to anaerobic respiration. We also apply MIRA to an Autism Spectrum Disorder gene expression dataset. Results indicate that MIRA reports metabolites that highly overlap with recently found metabolic biomarkers in the autism literature. Overall, MIRA is a promising algorithm for detecting metabolic drug targets and understanding the relation between gene expression and metabolic activity. Availability and

  19. Mutual information-based feature selection for radiomics

    NASA Astrophysics Data System (ADS)

    Oubel, Estanislao; Beaumont, Hubert; Iannessi, Antoine

    2016-03-01

    Background The extraction and analysis of image features (radiomics) is a promising field in the precision medicine era, with applications to prognosis, prediction, and response to treatment quantification. In this work, we present a mutual information - based method for quantifying reproducibility of features, a necessary step for qualification before their inclusion in big data systems. Materials and Methods Ten patients with Non-Small Cell Lung Cancer (NSCLC) lesions were followed over time (7 time points in average) with Computed Tomography (CT). Five observers segmented lesions by using a semi-automatic method and 27 features describing shape and intensity distribution were extracted. Inter-observer reproducibility was assessed by computing the multi-information (MI) of feature changes over time, and the variability of global extrema. Results The highest MI values were obtained for volume-based features (VBF). The lesion mass (M), surface to volume ratio (SVR) and volume (V) presented statistically significant higher values of MI than the rest of features. Within the same VBF group, SVR showed also the lowest variability of extrema. The correlation coefficient (CC) of feature values was unable to make a difference between features. Conclusions MI allowed to discriminate three features (M, SVR, and V) from the rest in a statistically significant manner. This result is consistent with the order obtained when sorting features by increasing values of extrema variability. MI is a promising alternative for selecting features to be considered as surrogate biomarkers in a precision medicine context.

  20. Mutual information-based LPI optimisation for radar network

    NASA Astrophysics Data System (ADS)

    Shi, Chenguang; Zhou, Jianjiang; Wang, Fei; Chen, Jun

    2015-07-01

    Radar network can offer significant performance improvement for target detection and information extraction employing spatial diversity. For a fixed number of radars, the achievable mutual information (MI) for estimating the target parameters may extend beyond a predefined threshold with full power transmission. In this paper, an effective low probability of intercept (LPI) optimisation algorithm is presented to improve LPI performance for radar network. Based on radar network system model, we first provide Schleher intercept factor for radar network as an optimisation metric for LPI performance. Then, a novel LPI optimisation algorithm is presented, where for a predefined MI threshold, Schleher intercept factor for radar network is minimised by optimising the transmission power allocation among radars in the network such that the enhanced LPI performance for radar network can be achieved. The genetic algorithm based on nonlinear programming (GA-NP) is employed to solve the resulting nonconvex and nonlinear optimisation problem. Some simulations demonstrate that the proposed algorithm is valuable and effective to improve the LPI performance for radar network.

  1. Estimation and classification by sigmoids based on mutual information

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1994-01-01

    An estimate of the probability density function of a random vector is obtained by maximizing the mutual information between the input and the output of a feedforward network of sigmoidal units with respect to the input weights. Classification problems can be solved by selecting the class associated with the maximal estimated density. Newton's s method, applied to an estimated density, yields a recursive maximum likelihood estimator, consisting of a single internal layer of sigmoids, for a random variable or a random sequence. Applications to the diamond classification and to the prediction of a sun-spot process are demonstrated.

  2. Certainty relations, mutual entanglement, and nondisplaceable manifolds

    NASA Astrophysics Data System (ADS)

    Puchała, Zbigniew; Rudnicki, Łukasz; Chabuda, Krzysztof; Paraniak, Mikołaj; Życzkowski, Karol

    2015-09-01

    We derive explicit bounds for the average entropy characterizing measurements of a pure quantum state of size N in L orthogonal bases. Lower bounds lead to novel entropic uncertainty relations, while upper bounds allow us to formulate universal certainty relations. For L =2 the maximal average entropy saturates at logN because there exists a mutually coherent state, but certainty relations are shown to be nontrivial for L ≥3 measurements. In the case of a prime power dimension, N =pk , and the number of measurements L =N +1 , the upper bound for the average entropy becomes minimal for a collection of mutually unbiased bases. An analogous approach is used to study entanglement with respect to L different splittings of a composite system linked by bipartite quantum gates. We show that, for any two-qubit unitary gate U ∈U(4 ) there exist states being mutually separable or mutually entangled with respect to both splittings (related by U ) of the composite system. The latter statement follows from the fact that the real projective space R P3⊂C P3 is nondisplaceable by a unitary transformation. For L =3 splittings the maximal sum of L entanglement entropies is conjectured to achieve its minimum for a collection of three mutually entangled bases, formed by two mutually entangling gates.

  3. Building an unbiased sample of quiescent galaxies up to z=2.5 based on the Mg(UV) absorption index

    NASA Astrophysics Data System (ADS)

    Domínguez Sánchez, H.; Eliche-Moral, M. Carmen; Pérez-González, P. G.; Esquej, P.; Alcalde-Pampliega, B.; SHARDS Team

    2015-05-01

    Samples of ``red & dead" galaxies selected through traditional color-based techniques usually suffer from contamination by strongly dust obscured sources. We are using GTC/OSIRIS data from the SHARDS project on the GOODSN field to define unbiased samples of really quiescent massive galaxies at different redshifts up to z=2.5. By measuring the Mg(UV) absorption index in the pseudo-spectra of these galaxies, we intend to determine the redshift evolution of the characteristic age of their stellar populations to shed some light into their assembly epoch.

  4. School-Based Mutual Support Groups for Low-Income Parents.

    ERIC Educational Resources Information Center

    Simoni, Jane M.; Adelman, Howard S.

    1993-01-01

    School-based mutual support groups (MSGs) are proposed to enhance school involvement of parents from lower socioeconomic and ethnic minority backgrounds. A school-based MSG format is presented with results of a survey of interests from 62 parents (36 respondents and 26 nonrespondents) and a discussion of a pilot demonstration in 3 urban elementary…

  5. Managing Mutual Orientation in the Absence of Physical Copresence: Multiparty Voice-Based Chat Room Interaction

    ERIC Educational Resources Information Center

    Jenks, Christopher Joseph; Brandt, Adam

    2013-01-01

    This study investigates the interactional work involved in ratifying mutual participation in online, multiparty, voice-based chat rooms. The purpose of this article is to provide a preliminary sketch of how talk and participation is managed in a spoken communication environment that comprises interactants who are not physically copresent but are…

  6. Study on the technology of mutual alignment based on the four-quadrant photo electric detector

    NASA Astrophysics Data System (ADS)

    Hu, Ya-bin; Wang, Miao

    2015-11-01

    Panoramic stereo cameras and laser radars have their own coordinate system in the dynamic spatial sensing area and they have to determine the position relationship between each other through joint calibration. As using the traditional technology of mutual alignment based on the telescope cross wire is tedious and requires high operating skills, a new method of mutual alignment using lasers and four-quadrant photo electric detectors is provided after analyzing the working principle of four-quadrant photo electric detectors. Firstly make the laser beam irradiate the active area of the four-quadrant photo electric detector through coarse aiming. Then the center of a light spot offset relative to the center of the active area can be obtained according to the output voltage of four quadrants. The pose of two instruments can be adjusted properly to realize mutual alignment. The experimental results indicate that the alignment accuracy of four-quadrant detectors can meet the requirements of mutual alignment, which provides a new idea for joint calibration.

  7. A Secure ECC-based RFID Mutual Authentication Protocol to Enhance Patient Medication Safety.

    PubMed

    Jin, Chunhua; Xu, Chunxiang; Zhang, Xiaojun; Li, Fagen

    2016-01-01

    Patient medication safety is an important issue in patient medication systems. In order to prevent medication errors, integrating Radio Frequency Identification (RFID) technology into automated patient medication systems is required in hospitals. Based on RFID technology, such systems can provide medical evidence for patients' prescriptions and medicine doses, etc. Due to the mutual authentication between the medication server and the tag, RFID authentication scheme is the best choice for automated patient medication systems. In this paper, we present a RFID mutual authentication scheme based on elliptic curve cryptography (ECC) to enhance patient medication safety. Our scheme can achieve security requirements and overcome various attacks existing in other schemes. In addition, our scheme has better performance in terms of computational cost and communication overhead. Therefore, the proposed scheme is well suitable for patient medication systems. PMID:26573649

  8. Comparison of co-expression measures: mutual information, correlation, and model based indices

    PubMed Central

    2012-01-01

    Background Co-expression measures are often used to define networks among genes. Mutual information (MI) is often used as a generalized correlation measure. It is not clear how much MI adds beyond standard (robust) correlation measures or regression model based association measures. Further, it is important to assess what transformations of these and other co-expression measures lead to biologically meaningful modules (clusters of genes). Results We provide a comprehensive comparison between mutual information and several correlation measures in 8 empirical data sets and in simulations. We also study different approaches for transforming an adjacency matrix, e.g. using the topological overlap measure. Overall, we confirm close relationships between MI and correlation in all data sets which reflects the fact that most gene pairs satisfy linear or monotonic relationships. We discuss rare situations when the two measures disagree. We also compare correlation and MI based approaches when it comes to defining co-expression network modules. We show that a robust measure of correlation (the biweight midcorrelation transformed via the topological overlap transformation) leads to modules that are superior to MI based modules and maximal information coefficient (MIC) based modules in terms of gene ontology enrichment. We present a function that relates correlation to mutual information which can be used to approximate the mutual information from the corresponding correlation coefficient. We propose the use of polynomial or spline regression models as an alternative to MI for capturing non-linear relationships between quantitative variables. Conclusion The biweight midcorrelation outperforms MI in terms of elucidating gene pairwise relationships. Coupled with the topological overlap matrix transformation, it often leads to more significantly enriched co-expression modules. Spline and polynomial networks form attractive alternatives to MI in case of non-linear relationships

  9. Feature selection of fMRI data based on normalized mutual information and fisher discriminant ratio.

    PubMed

    Wang, Yanbin; Ji, Junzhong; Liang, Peipeng

    2016-03-17

    Pattern classification has been increasingly used in functional magnetic resonance imaging (fMRI) data analysis. However, the classification performance is restricted by the high dimensional property and noises of the fMRI data. In this paper, a new feature selection method (named as "NMI-F") was proposed by sequentially combining the normalized mutual information (NMI) and fisher discriminant ratio. In NMI-F, the normalized mutual information was firstly used to evaluate the relationships between features, and fisher discriminant ratio was then applied to calculate the importance of each feature involved. Two fMRI datasets (task-related and resting state) were used to test the proposed method. It was found that classification base on the NMI-F method could differentiate the brain cognitive and disease states effectively, and the proposed NMI-F method was prior to the other related methods. The current results also have implications to the future studies. PMID:27257882

  10. Artifact reduction in mutual-information-based CT-MR image registration

    NASA Astrophysics Data System (ADS)

    Wei, Mingxiu; Liu, Jundong; Liu, Junhong

    2004-05-01

    Abstract Mutual information (MI) is currently the most popular match metric in handling the registration problem for multi modality images. However, interpolation artifacts impose deteriorating effects to the accuracy and robustness of MI-based methods. This paper analyzes the generation mechanism of the artifacts inherent in linear partial volume interpolation (PVI) and shows that the mutual information resulted from PVI is a convex function within each voxel grid. We conclude that the generation of the artifacts is due to two facts: 1) linear interpolation causes the histogram bin values to change at a synchronized pace; 2) entropy computation function Σxlgx is convex. As a remedy we propose to use non-uniform interpolation functions as the interpolation kernels in estimating the joint histogram. Cubic B-splin and Gaussian interpolators are compared and we demonstrate the improvements via experiments on misalignments between CT/MR brain scans.

  11. Robust Feature Selection from Microarray Data Based on Cooperative Game Theory and Qualitative Mutual Information

    PubMed Central

    Mortazavi, Atiyeh; Moattar, Mohammad Hossein

    2016-01-01

    High dimensionality of microarray data sets may lead to low efficiency and overfitting. In this paper, a multiphase cooperative game theoretic feature selection approach is proposed for microarray data classification. In the first phase, due to high dimension of microarray data sets, the features are reduced using one of the two filter-based feature selection methods, namely, mutual information and Fisher ratio. In the second phase, Shapley index is used to evaluate the power of each feature. The main innovation of the proposed approach is to employ Qualitative Mutual Information (QMI) for this purpose. The idea of Qualitative Mutual Information causes the selected features to have more stability and this stability helps to deal with the problem of data imbalance and scarcity. In the third phase, a forward selection scheme is applied which uses a scoring function to weight each feature. The performance of the proposed method is compared with other popular feature selection algorithms such as Fisher ratio, minimum redundancy maximum relevance, and previous works on cooperative game based feature selection. The average classification accuracy on eleven microarray data sets shows that the proposed method improves both average accuracy and average stability compared to other approaches. PMID:27127506

  12. An Efficient and Adaptive Mutual Authentication Framework for Heterogeneous Wireless Sensor Network-Based Applications

    PubMed Central

    Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

    2014-01-01

    Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications. PMID:24521942

  13. An efficient and adaptive mutual authentication framework for heterogeneous wireless sensor network-based applications.

    PubMed

    Kumar, Pardeep; Ylianttila, Mika; Gurtov, Andrei; Lee, Sang-Gon; Lee, Hoon-Jae

    2014-01-01

    Robust security is highly coveted in real wireless sensor network (WSN) applications since wireless sensors' sense critical data from the application environment. This article presents an efficient and adaptive mutual authentication framework that suits real heterogeneous WSN-based applications (such as smart homes, industrial environments, smart grids, and healthcare monitoring). The proposed framework offers: (i) key initialization; (ii) secure network (cluster) formation (i.e., mutual authentication and dynamic key establishment); (iii) key revocation; and (iv) new node addition into the network. The correctness of the proposed scheme is formally verified. An extensive analysis shows the proposed scheme coupled with message confidentiality, mutual authentication and dynamic session key establishment, node privacy, and message freshness. Moreover, the preliminary study also reveals the proposed framework is secure against popular types of attacks, such as impersonation attacks, man-in-the-middle attacks, replay attacks, and information-leakage attacks. As a result, we believe the proposed framework achieves efficiency at reasonable computation and communication costs and it can be a safeguard to real heterogeneous WSN applications. PMID:24521942

  14. Weighted mutual information analysis substantially improves domain-based functional network models

    PubMed Central

    Shim, Jung Eun; Lee, Insuk

    2016-01-01

    Motivation: Functional protein–protein interaction (PPI) networks elucidate molecular pathways underlying complex phenotypes, including those of human diseases. Extrapolation of domain–domain interactions (DDIs) from known PPIs is a major domain-based method for inferring functional PPI networks. However, the protein domain is a functional unit of the protein. Therefore, we should be able to effectively infer functional interactions between proteins based on the co-occurrence of domains. Results: Here, we present a method for inferring accurate functional PPIs based on the similarity of domain composition between proteins by weighted mutual information (MI) that assigned different weights to the domains based on their genome-wide frequencies. Weighted MI outperforms other domain-based network inference methods and is highly predictive for pathways as well as phenotypes. A genome-scale human functional network determined by our method reveals numerous communities that are significantly associated with known pathways and diseases. Domain-based functional networks may, therefore, have potential applications in mapping domain-to-pathway or domain-to-phenotype associations. Availability and Implementation: Source code for calculating weighted mutual information based on the domain profile matrix is available from www.netbiolab.org/w/WMI. Contact: Insuklee@yonsei.ac.kr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27207946

  15. The (w)hole survey: An unbiased sample study of transition disk candidates based on Spitzer catalogs

    NASA Astrophysics Data System (ADS)

    van der Marel, N.; Verhaar, B. W.; van Terwisga, S.; Merín, B.; Herczeg, G.; Ligterink, N. F. W.; van Dishoeck, E. F.

    2016-08-01

    Understanding disk evolution and dissipation is essential for studies of planet formation. Transition disks, i.e., disks with large dust cavities and gaps, are promising candidates of active evolution. About two dozen candidates, selected by their spectral energy distribution (SED), have been confirmed to have dust cavities through millimeter interferometric imaging, but this sample is biased toward the brightest disks. The Spitzer surveys of nearby low-mass star-forming regions have resulted in more than 4000 young stellar objects. Using color criteria, we selected a sample of ~150 candidates and an additional 40 candidates and known transition disks from the literature. The Spitzer data were complemented by new observations at longer wavelengths, including new JCMT and APEX submillimeter photometry, and WISE and Herschel-PACS mid- and far-infrared photometry. Furthermore, optical spectroscopy was obtained and stellar types were derived for 85% of the sample, including information from the literature. The SEDs were fit to a grid of RADMC-3D disk models with a limited number of parameters: disk mass, inner disk mass, scale height and flaring, and disk cavity radius, where the latter is the main parameter of interest. About 72% of our targets possibly have dust cavities based on the SED. The derived cavity sizes are consistent with imaging/modeling results in the literature, where available. Trends are found with Ldisk over L∗ ratio and stellar mass and a possible connection with exoplanet orbital radii. A comparison with a previous study where color observables are used reveals large overlap between their category of planet-forming disks and our transition disks with cavities. A large number of the new transition disk candidates are suitable for follow-up observations with ALMA. Full Tables 4, 5, A.1-A.3, C.1, and D.1 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  16. Unbiased Detection of Respiratory Viruses by Use of RNA Sequencing-Based Metagenomics: a Systematic Comparison to a Commercial PCR Panel.

    PubMed

    Graf, Erin H; Simmon, Keith E; Tardif, Keith D; Hymas, Weston; Flygare, Steven; Eilbeck, Karen; Yandell, Mark; Schlaberg, Robert

    2016-04-01

    Current infectious disease molecular tests are largely pathogen specific, requiring test selection based on the patient's symptoms. For many syndromes caused by a large number of viral, bacterial, or fungal pathogens, such as respiratory tract infections, this necessitates large panels of tests and has limited yield. In contrast, next-generation sequencing-based metagenomics can be used for unbiased detection of any expected or unexpected pathogen. However, barriers for its diagnostic implementation include incomplete understanding of analytical performance and complexity of sequence data analysis. We compared detection of known respiratory virus-positive (n= 42) and unselected (n= 67) pediatric nasopharyngeal swabs using an RNA sequencing (RNA-seq)-based metagenomics approach and Taxonomer, an ultrarapid, interactive, web-based metagenomics data analysis tool, with an FDA-cleared respiratory virus panel (RVP; GenMark eSensor). Untargeted metagenomics detected 86% of known respiratory virus infections, and additional PCR testing confirmed RVP results for only 2 (33%) of the discordant samples. In unselected samples, untargeted metagenomics had excellent agreement with the RVP (93%). In addition, untargeted metagenomics detected an additional 12 viruses that were either not targeted by the RVP or missed due to highly divergent genome sequences. Normalized viral read counts for untargeted metagenomics correlated with viral burden determined by quantitative PCR and showed high intrarun and interrun reproducibility. Partial or full-length viral genome sequences were generated in 86% of RNA-seq-positive samples, allowing assessment of antiviral resistance, strain-level typing, and phylogenetic relatedness. Overall, untargeted metagenomics had high agreement with a sensitive RVP, detected viruses not targeted by the RVP, and yielded epidemiologically and clinically valuable sequence information. PMID:26818672

  17. Interpretation of personal genome sequencing data in terms of disease ranks based on mutual information

    PubMed Central

    2015-01-01

    Background The rapid advances in genome sequencing technologies have resulted in an unprecedented number of genome variations being discovered in humans. However, there has been very limited coverage of interpretation of the personal genome sequencing data in terms of diseases. Methods In this paper we present the first computational analysis scheme for interpreting personal genome data by simultaneously considering the functional impact of damaging variants and curated disease-gene association data. This method is based on mutual information as a measure of the relative closeness between the personal genome and diseases. We hypothesize that a higher mutual information score implies that the personal genome is more susceptible to a particular disease than other diseases. Results The method was applied to the sequencing data of 50 acute myeloid leukemia (AML) patients in The Cancer Genome Atlas. The utility of associations between a disease and the personal genome was explored using data of healthy (control) people obtained from the 1000 Genomes Project. The ranks of the disease terms in the AML patient group were compared with those in the healthy control group using "Leukemia, Myeloid, Acute" (C04.557.337.539.550) as the corresponding MeSH disease term. The mutual information rank of the disease term was substantially higher in the AML patient group than in the healthy control group, which demonstrates that the proposed methodology can be successfully applied to infer associations between the personal genome and diseases. Conclusions Overall, the area under the receiver operating characteristics curve was significantly larger for the AML patient data than for the healthy controls. This methodology could contribute to consequential discoveries and explanations for mining personal genome sequencing data in terms of diseases, and have versatility with respect to genomic-based knowledge such as drug-gene and environmental-factor-gene interactions. PMID:26045178

  18. A Semidefinite Programming Based Search Strategy for Feature Selection with Mutual Information Measure.

    PubMed

    Naghibi, Tofigh; Hoffmann, Sarah; Pfister, Beat

    2015-08-01

    Feature subset selection, as a special case of the general subset selection problem, has been the topic of a considerable number of studies due to the growing importance of data-mining applications. In the feature subset selection problem there are two main issues that need to be addressed: (i) Finding an appropriate measure function than can be fairly fast and robustly computed for high-dimensional data. (ii) A search strategy to optimize the measure over the subset space in a reasonable amount of time. In this article mutual information between features and class labels is considered to be the measure function. Two series expansions for mutual information are proposed, and it is shown that most heuristic criteria suggested in the literature are truncated approximations of these expansions. It is well-known that searching the whole subset space is an NP-hard problem. Here, instead of the conventional sequential search algorithms, we suggest a parallel search strategy based on semidefinite programming (SDP) that can search through the subset space in polynomial time. By exploiting the similarities between the proposed algorithm and an instance of the maximum-cut problem in graph theory, the approximation ratio of this algorithm is derived and is compared with the approximation ratio of the backward elimination method. The experiments show that it can be misleading to judge the quality of a measure solely based on the classification accuracy, without taking the effect of the non-optimum search strategy into account. PMID:26352993

  19. Mutual Lewis acid-base interactions of cations and anions in ionic liquids.

    PubMed

    Holzweber, Markus; Lungwitz, Ralf; Doerfler, Denise; Spange, Stefan; Koel, Mihkel; Hutter, Herbert; Linert, Wolfgang

    2013-01-01

    Solute properties are known to be strongly influenced by solvent molecules due to solvation. This is due to mutual interaction as both the properties of the solute and of the solvent strongly depend on each other. The present paper is based on the idea that ionic liquids are cations solvated by anions and anions solvated by cations. To show this (in this system strongly pronounced) interaction the long time established donor-acceptor concept for solvents and ions in solution by Viktor Gutmann is extended to ionic liquids. A number of solvent parameters, such as the Kamlet-Abboud-Taft and the Dimroth-Reichardt E(T) scale for ionic liquids neglect this mutual influence, which, however, seems to be in fact necessary to get a proper description of ionic liquid properties. It is shown how strong such parameters vary when the influence of the counter ion is taken into account. Furthermore, acceptor and donor numbers for ionic liquids are presented. PMID:23180598

  20. A mutual-information-based mining method for marine abnormal association rules

    NASA Astrophysics Data System (ADS)

    Cunjin, Xue; Wanjiao, Song; Lijuan, Qin; Qing, Dong; Xiaoyang, Wen

    2015-03-01

    Long time series of remote sensing images are a key source of data for exploring large-scale marine abnormal association patterns, but pose significant challenges for traditional approaches to spatiotemporal analysis. This paper proposes a mutual-information-based quantitative association rule-mining algorithm (MIQarma) to address these challenges. MIQarma comprises three key steps. First, MIQarma calculates the asymmetrical mutual information between items with one scan of the database, and extracts pair-wise related items according to the user-specified information threshold. Second, a linking-pruning-generating recursive loop generates (k+1)-dimensional candidate association rules from k-dimensional rules on basis of the user-specified minimum support threshold, and this step is repeated until no more candidate association rules are generated. Finally, strong association rules are generated according to the user-specified minimum evaluation indicators. To demonstrate the feasibility and efficiency of MIQarma, we present two case studies: one considers performance analysis and the other identifies marine abnormal association relationships.

  1. An Assessment of Hermite Function Based Approximations of Mutual Information Applied to Independent Component Analysis

    NASA Astrophysics Data System (ADS)

    Sorensen, Julian

    2008-12-01

    At the heart of many ICA techniques is a nonparametric estimate of an information measure, usually via nonparametric density estimation, for example, kernel density estimation. While not as popular as kernel density estimators, orthogonal functions can be used for nonparametric density estimation (via a truncated series expansion whose coefficients are calculated from the observed data). While such estimators do not necessarily yield a valid density, which kernel density estimators do, they are faster to calculate than kernel density estimators, in particular for a modified version of Renyi's entropy of order 2. In this paper, we compare the performance of ICA using Hermite series based estimates of Shannon's and Renyi's mutual information, to that of Gaussian kernel based estimates. The comparisons also include ICA using the RADICAL estimate of Shannon's entropy and a FastICA estimate of neg-entropy.

  2. Power Spectrum and Mutual Information Analyses of DNA Base (Nucleotide) Sequences

    NASA Astrophysics Data System (ADS)

    Isohata, Yasuhiko; Hayashi, Masaki

    2003-03-01

    On the basis of the power spectrum analyses for the base (nucleotide) sequences of various genes, we have studied long-range correlations in total base sequences which are expressed as 1/fα, behaviour of the exponent α for the accumulated base sequences as well as periodicities at short range. In particular from the analysis of content rate distributions of α we have obtained the average value \\barα=0.40± 0.01 and \\barα=0.20± 0.01 for the human genes and S. cerevisiae genes, respectively. We have also performed the analyses using the mutual information function. We show that there exists a clear difference between the content rate distributions of correlation lengths for the sample human genes and the S. cerevisiae genes. We are led to a conjecture that the elongation of the correlation length in the base sequences of genes from the early eukaryote (S. cerevisiae) to the late eukaryote (human) should be the definite reflection of the evolutionary process.

  3. Registration of 2D to 3D joint images using phase-based mutual information

    NASA Astrophysics Data System (ADS)

    Dalvi, Rupin; Abugharbieh, Rafeef; Pickering, Mark; Scarvell, Jennie; Smith, Paul

    2007-03-01

    Registration of two dimensional to three dimensional orthopaedic medical image data has important applications particularly in the area of image guided surgery and sports medicine. Fluoroscopy to computer tomography (CT) registration is an important case, wherein digitally reconstructed radiographs derived from the CT data are registered to the fluoroscopy data. Traditional registration metrics such as intensity-based mutual information (MI) typically work well but often suffer from gross misregistration errors when the image to be registered contains a partial view of the anatomy visible in the target image. Phase-based MI provides a robust alternative similarity measure which, in addition to possessing the general robustness and noise immunity that MI provides, also employs local phase information in the registration process which makes it less susceptible to the aforementioned errors. In this paper, we propose using the complex wavelet transform for computing image phase information and incorporating that into a phase-based MI measure for image registration. Tests on a CT volume and 6 fluoroscopy images of the knee are presented. The femur and the tibia in the CT volume were individually registered to the fluoroscopy images using intensity-based MI, gradient-based MI and phase-based MI. Errors in the coordinates of fiducials present in the bone structures were used to assess the accuracy of the different registration schemes. Quantitative results demonstrate that the performance of intensity-based MI was the worst. Gradient-based MI performed slightly better, while phase-based MI results were the best consistently producing the lowest errors.

  4. Mutual information-based context template modeling for bitplane coding in remote sensing image compression

    NASA Astrophysics Data System (ADS)

    Zhang, Yongfei; Cao, Haiheng; Jiang, Hongxu; Li, Bo

    2016-04-01

    As remote sensing image applications are often characterized with limited bandwidth and high-quality demands, higher coding performance of remote sensing images are desirable. The embedded block coding with optimal truncation (EBCOT) is the fundamental part of JPEG2000 image compression standard. However, EBCOT only considers correlation within a sub-band and utilizes a context template of eight spatially neighboring coefficients in prediction. The existing optimization methods in literature using the current context template prove little performance improvements. To address this problem, this paper presents a new mutual information (MI)-based context template selection and modeling method. By further considering the correlation across the sub-bands, the potential prediction coefficients, including neighbors, far neighbors, parent and parent neighbors, are comprehensively examined and selected in such a manner that achieves a nice trade-off between the MI-based correlation criterion and the prediction complexity. Based on the selected context template, a high-order prediction model, which jointly considers the weight and the significance state of each coefficient, is proposed. Experimental results show that the proposed algorithm consistently outperforms the benchmark JPEG2000 standard and state-of-the-art algorithms in term of coding efficiency at a competitive computational cost, which makes it desirable in real-time compression applications, especially for remote sensing images.

  5. Mutual solubility of water and structural/positional isomers of N-alkylpyridinium-based ionic liquids.

    PubMed

    Freire, Mara G; Neves, Catarina M S S; Shimizu, Karina; Bernardes, Carlos E S; Marrucho, Isabel M; Coutinho, João A P; Canongia Lopes, José N; Rebelo, Luís Paulo N

    2010-12-01

    Despite many previous important contributions to the characterization of the liquid-liquid phase behavior of ionic liquids (ILs) plus water systems, a gap still exists as far as the effect of isomers (of ILs) is concerned. Therefore, in this work, a comprehensive study of the liquid-liquid equilibria between water and isomeric pyridinium-based ionic liquids has been performed. Atmospheric pressure mutual solubilities between water and pyridinium-based ionic liquids combined with the common anion bis[(trifluoromethyl)sulfonyl]imide were experimentally determined between (288.15 and 318.15) K. The main goal of this work is to study the isomeric effects on the pyridinium-based cation, namely, the structural and positional isomerism, as well as the alkyl side chain length. To the best of our knowledge, the influence of both structural and positional isomerism on the liquid-liquid behavior in ionic-liquid-water-containing systems is an unexplored field and is here assessed for the first time. Moreover, from the experimental solubility data, several infinite dilution molar thermodynamic functions of solution, namely, the Gibbs energy, the enthalpy, and the entropy, were estimated and discussed. In addition, aiming at gathering a broader picture of the underlying thermodynamic solvation phenomenon, molecular dynamics simulations were also carried out for the same experimental systems. PMID:21077599

  6. Comparison and evaluation of joint histogram estimation methods for mutual information based image registration

    NASA Astrophysics Data System (ADS)

    Liang, Yongfang; Chen, Hua-mei

    2005-04-01

    Joint histogram is the only quantity required to calculate the mutual information (MI) between two images. For MI based image registration, joint histograms are often estimated through linear interpolation or partial volume interpolation (PVI). It has been pointed out that both methods may result in a phenomenon known as interpolation induced artifacts. In this paper, we implemented a wide range of interpolation/approximation kernels for joint histogram estimation. Some kernels are nonnegative. In this case, these kernels are applied in two ways as the linear kernel is applied in linear interpolation and PVI. In addition, we implemented two other joint histogram estimation methods devised to overcome the interpolation artifact problem. They are nearest neighbor interpolation with jittered sampling with/without histogram blurring and data resampling. We used the clinical data obtained from Vanderbilt University for all of the experiments. The objective of this study is to perform a comprehensive comparison and evaluation of different joint histogram estimation methods for MI based image registration in terms of artifacts reduction and registration accuracy.

  7. Fully Integrated Passive UHF RFID Tag for Hash-Based Mutual Authentication Protocol.

    PubMed

    Mikami, Shugo; Watanabe, Dai; Li, Yang; Sakiyama, Kazuo

    2015-01-01

    Passive radio-frequency identification (RFID) tag has been used in many applications. While the RFID market is expected to grow, concerns about security and privacy of the RFID tag should be overcome for the future use. To overcome these issues, privacy-preserving authentication protocols based on cryptographic algorithms have been designed. However, to the best of our knowledge, evaluation of the whole tag, which includes an antenna, an analog front end, and a digital processing block, that runs authentication protocols has not been studied. In this paper, we present an implementation and evaluation of a fully integrated passive UHF RFID tag that runs a privacy-preserving mutual authentication protocol based on a hash function. We design a single chip including the analog front end and the digital processing block. We select a lightweight hash function supporting 80-bit security strength and a standard hash function supporting 128-bit security strength. We show that when the lightweight hash function is used, the tag completes the protocol with a reader-tag distance of 10 cm. Similarly, when the standard hash function is used, the tag completes the protocol with the distance of 8.5 cm. We discuss the impact of the peak power consumption of the tag on the distance of the tag due to the hash function. PMID:26491714

  8. Fully Integrated Passive UHF RFID Tag for Hash-Based Mutual Authentication Protocol

    PubMed Central

    Mikami, Shugo; Watanabe, Dai; Li, Yang; Sakiyama, Kazuo

    2015-01-01

    Passive radio-frequency identification (RFID) tag has been used in many applications. While the RFID market is expected to grow, concerns about security and privacy of the RFID tag should be overcome for the future use. To overcome these issues, privacy-preserving authentication protocols based on cryptographic algorithms have been designed. However, to the best of our knowledge, evaluation of the whole tag, which includes an antenna, an analog front end, and a digital processing block, that runs authentication protocols has not been studied. In this paper, we present an implementation and evaluation of a fully integrated passive UHF RFID tag that runs a privacy-preserving mutual authentication protocol based on a hash function. We design a single chip including the analog front end and the digital processing block. We select a lightweight hash function supporting 80-bit security strength and a standard hash function supporting 128-bit security strength. We show that when the lightweight hash function is used, the tag completes the protocol with a reader-tag distance of 10 cm. Similarly, when the standard hash function is used, the tag completes the protocol with the distance of 8.5 cm. We discuss the impact of the peak power consumption of the tag on the distance of the tag due to the hash function. PMID:26491714

  9. An ensemble method based on uninformative variable elimination and mutual information for spectral multivariate calibration

    NASA Astrophysics Data System (ADS)

    Tan, Chao; Wang, Jinyue; Wu, Tong; Qin, Xin; Li, Menglong

    2010-12-01

    Based on the combination of uninformative variable elimination (UVE), bootstrap and mutual information (MI), a simple ensemble algorithm, named ESPLS, is proposed for spectral multivariate calibration (MVC). In ESPLS, those uninformative variables are first removed; and then a preparatory training set is produced by bootstrap, on which a MI spectrum of retained variables is calculated. The variables that exhibit higher MI than a defined threshold form a subspace on which a candidate partial least-squares (PLS) model is constructed. This process is repeated. After a number of candidate models are obtained, a small part of models is picked out to construct an ensemble model by simple/weighted average. Four near/mid-infrared (NIR/MIR) spectral datasets concerning the determination of six components are used to verify the proposed ESPLS. The results indicate that ESPLS is superior to UVEPLS and its combination with MI-based variable selection (SPLS) in terms of both the accuracy and robustness. Besides, from the perspective of end-users, ESPLS does not increase the complexity of a calibration when enhancing its performance.

  10. Mutual information image registration based on improved bee evolutionary genetic algorithm

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Tu, Jingzhi

    2009-07-01

    In recent years, the mutual information is regarded as a more efficient similarity metrics in the image registration. According to the features of mutual information image registration, the Bee Evolution Genetic Algorithm (BEGA) is chosen for optimizing parameters, which imitates swarm mating. Besides, we try our best adaptively set the initial parameters to improve the BEGA. The programming result shows the wonderful precision of the algorithm.

  11. Research on non rigid registration algorithm of DCE-MRI based on mutual information and optical flow

    NASA Astrophysics Data System (ADS)

    Yu, Shihua; Wang, Rui; Wang, Kaiyu; Xi, Mengmeng; Zheng, Jiashuo; Liu, Hui

    2015-07-01

    Image matching plays a very important role in the field of medical image, while the two image registration methods based on the mutual information and the optical flow are very effective. The experimental results show that the two methods have their prominent advantages. The method based on mutual information is good for the overall displacement, while the method based on optical flow is very sensitive to small deformation. In the breast DCE-MRI images studied in this paper, there is not only overall deformation caused by the patient, but also non rigid small deformation caused by respiratory deformation. In view of the above situation, the single-image registration algorithms cannot meet the actual needs of complex situations. After a comprehensive analysis to the advantages and disadvantages of these two methods, this paper proposes a registration algorithm of combining mutual information with optical flow field, and applies subtraction images of the reference image and the floating image as the main criterion to evaluate the registration effect, at the same time, applies the mutual information between image sequence values as auxiliary criterion. With the test of the example, this algorithm has obtained a better accuracy and reliability in breast DCE-MRI image sequences.

  12. IR and visual image registration based on mutual information and PSO-Powell algorithm

    NASA Astrophysics Data System (ADS)

    Zhuang, Youwen; Gao, Kun; Miu, Xianghu

    2014-11-01

    Infrared and visual image registration has a wide application in the fields of remote sensing and military. Mutual information (MI) has proved effective and successful in infrared and visual image registration process. To find the most appropriate registration parameters, optimal algorithms, such as Particle Swarm Optimization (PSO) algorithm or Powell search method, are often used. The PSO algorithm has strong global search ability and search speed is fast at the beginning, while the weakness is low search performance in late search stage. In image registration process, it often takes a lot of time to do useless search and solution's precision is low. Powell search method has strong local search ability. However, the search performance and time is more sensitive to initial values. In image registration, it is often obstructed by local maximum and gets wrong results. In this paper, a novel hybrid algorithm, which combined PSO algorithm and Powell search method, is proposed. It combines both advantages that avoiding obstruction caused by local maximum and having higher precision. Firstly, using PSO algorithm gets a registration parameter which is close to global minimum. Based on the result in last stage, the Powell search method is used to find more precision registration parameter. The experimental result shows that the algorithm can effectively correct the scale, rotation and translation additional optimal algorithm. It can be a good solution to register infrared difference of two images and has a greater performance on time and precision than traditional and visible images.

  13. Characteristics analysis of acupuncture electroencephalograph based on mutual information Lempel—Ziv complexity

    NASA Astrophysics Data System (ADS)

    Luo, Xi-Liu; Wang, Jiang; Han, Chun-Xiao; Deng, Bin; Wei, Xi-Le; Bian, Hong-Rui

    2012-02-01

    As a convenient approach to the characterization of cerebral cortex electrical information, electroencephalograph (EEG) has potential clinical application in monitoring the acupuncture effects. In this paper, a method composed of the mutual information method and Lempel—Ziv complexity method (MILZC) is proposed to investigate the effects of acupuncture on the complexity of information exchanges between different brain regions based on EEGs. In the experiments, eight subjects are manually acupunctured at ‘Zusanli’ acupuncture point (ST-36) with different frequencies (i.e., 50, 100, 150, and 200 times/min) and the EEGs are recorded simultaneously. First, MILZC values are compared in general. Then average brain connections are used to quantify the effectiveness of acupuncture under the above four frequencies. Finally, significance index P values are used to study the spatiality of the acupuncture effect on the brain. Three main findings are obtained: (i) MILZC values increase during the acupuncture; (ii) manual acupunctures (MAs) with 100 times/min and 150 times/min are more effective than with 50 times/min and 200 times/min; (iii) contralateral hemisphere activation is more prominent than ipsilateral hemisphere's. All these findings suggest that acupuncture contributes to the increase of brain information exchange complexity and the MILZC method can successfully describe these changes.

  14. A mutual information-based metric for evaluation of fMRI data-processing approaches.

    PubMed

    Afshin-Pour, Babak; Soltanian-Zadeh, Hamid; Hossein-Zadeh, Gholam-Ali; Grady, Cheryl L; Strother, Stephen C

    2011-05-01

    We propose a novel approach for evaluating the performance of activation detection in real (experimental) datasets using a new mutual information (MI)-based metric and compare its sensitivity to several existing performance metrics in both simulated and real datasets. The proposed approach is based on measuring the approximate MI between the fMRI time-series of a validation dataset and a calculated activation map (thresholded label map or continuous map) from an independent training dataset. The MI metric is used to measure the amount of information preserved during the extraction of an activation map from experimentally related fMRI time-series. The processing method that preserves maximal information between the maps and related time-series is proposed to be superior. The results on simulation datasets for multiple analysis models are consistent with the results of ROC curves, but are shown to have lower information content than for real datasets, limiting their generalizability. In real datasets for group analyses using the general linear model (GLM; FSL4 and SPM5), we show that MI values are (1) larger for groups of 15 versus 10 subjects and (2) more sensitive measures than reproducibility (for continuous maps) or Jaccard overlap metrics (for thresholded maps). We also show that (1) for an increasing fraction of nominally active voxels, both MI and false discovery rate (FDR) increase, and (2) at a fixed FDR, GLM using FSL4 tends to extract more voxels and more information than SPM5 using the default processing techniques in each package. PMID:20533565

  15. New direction of arrival estimation of coherent signals based on reconstructing matrix under unknown mutual coupling

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Li, Weixing; Zhang, Yue; Chen, Zengping

    2016-01-01

    A direction of arrival (DOA) estimation algorithm for coherent signals in the presence of unknown mutual coupling is proposed. A group of auxiliary sensors in a uniform linear array are applied to eliminate the effects on the orthogonality of subspaces brought by mutual coupling. Then, a Toeplitz matrix, whose rank is independent of the coherency between impinging signals, is reconstructed to eliminate the rank loss of the spatial covariance matrix. Therefore, the signal and noise subspaces can be estimated properly. This method can estimate the DOAs of coherent signals under unknown mutual coupling accurately without any iteration and calibration sources. It has a low computational burden and high accuracy. Simulation results demonstrate the effectiveness of the algorithm.

  16. On the feature selection criterion based on an approximation of multidimensional mutual information.

    PubMed

    Balagani, Kiran S; Phoha, Vir V

    2010-07-01

    We derive the feature selection criterion presented in [CHECK END OF SENTENCE] and [CHECK END OF SENTENCE] from the multidimensional mutual information between features and the class. Our derivation: 1) specifies and validates the lower-order dependency assumptions of the criterion and 2) mathematically justifies the utility of the criterion by relating it to Bayes classification error. PMID:20489237

  17. School-Based Mutual Support Groups for Parents: An Intervention Guidebook.

    ERIC Educational Resources Information Center

    Simoni, Jane M.

    This handbook focuses on steps and tasks related to establishing mutual support groups for parents in a school setting. A sequential approach is described that involves: working within the school to get started; recruiting members; training parents how to run their own meetings; and offering off-site consultation as requested. The first section…

  18. School-Based Mutual Support Groups (For Parents, Staff, Older Students). A Technical Aid Packet.

    ERIC Educational Resources Information Center

    Simoni, Jane, Comp.

    Mutual support groups in schools can be developed as part of strategies to provide assistance for parents or other family members, students, or school staff. These groups can also be used to provide support for newcomers and others in periods of transition. This technical aid packet describes the process as used with parents, but the procedures…

  19. TELEsarPHONE: Mutual Telexistence Master-Slave Communication System Based on Retroreflective Projection Technology

    NASA Astrophysics Data System (ADS)

    Tachi, Susumu; Kawakami, Naoki; Nii, Hideaki; Watanabe, Kouichi; Minamizawa, Kouta

    TELEsarPHONE is a conceptual prototype of a mutual telexistence system, designed for face-to-face telecommunication via robots. Because of the development of telexistence technology, we can acquire a feeling that we are present in several actual remote places using remote robots as our surrogates and can work and act freely there. However, people in the place where someone telexists using a robot see only the robot, and they cannot feel the existence of the telexisting person. Mutual telexistence aims to solve this problem so that the existence of a telexisting person (visitor) is apparent to the people in the remote environment by providing mutual sensations of presence. On the basis of the concept of mutual telexistence, we have designed and developed a prototype of a telexistence master-slave system for remote communication by applying retroreflective projection technology. In the TELEsarPHONE system, the face and chest of the slave robot TELESAR II are covered by retroreflective material. To provide the feeling of existence, the real-time image of the visitor is projected onto the robot so that people can see the visitor in real time.

  20. Unbiased Cell-based Screening in a Neuronal Cell Model of Batten Disease Highlights an Interaction between Ca2+ Homeostasis, Autophagy, and CLN3 Protein Function.

    PubMed

    Chandrachud, Uma; Walker, Mathew W; Simas, Alexandra M; Heetveld, Sasja; Petcherski, Anton; Klein, Madeleine; Oh, Hyejin; Wolf, Pavlina; Zhao, Wen-Ning; Norton, Stephanie; Haggarty, Stephen J; Lloyd-Evans, Emyr; Cotman, Susan L

    2015-06-01

    Abnormal accumulation of undigested macromolecules, often disease-specific, is a major feature of lysosomal and neurodegenerative disease and is frequently attributed to defective autophagy. The mechanistic underpinnings of the autophagy defects are the subject of intense research, which is aided by genetic disease models. To gain an improved understanding of the pathways regulating defective autophagy specifically in juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), a neurodegenerative disease of childhood, we developed and piloted a GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) screening assay to identify, in an unbiased fashion, genotype-sensitive small molecule autophagy modifiers, employing a JNCL neuronal cell model bearing the most common disease mutation in CLN3. Thapsigargin, a sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) Ca(2+) pump inhibitor, reproducibly displayed significantly more activity in the mouse JNCL cells, an effect that was also observed in human-induced pluripotent stem cell-derived JNCL neural progenitor cells. The mechanism of thapsigargin sensitivity was Ca(2+)-mediated, and autophagosome accumulation in JNCL cells could be reversed by Ca(2+) chelation. Interrogation of intracellular Ca(2+) handling highlighted alterations in endoplasmic reticulum, mitochondrial, and lysosomal Ca(2+) pools and in store-operated Ca(2+) uptake in JNCL cells. These results further support an important role for the CLN3 protein in intracellular Ca(2+) handling and in autophagic pathway flux and establish a powerful new platform for therapeutic screening. PMID:25878248

  1. Unbiased Cell-based Screening in a Neuronal Cell Model of Batten Disease Highlights an Interaction between Ca2+ Homeostasis, Autophagy, and CLN3 Protein Function*

    PubMed Central

    Chandrachud, Uma; Walker, Mathew W.; Simas, Alexandra M.; Heetveld, Sasja; Petcherski, Anton; Klein, Madeleine; Oh, Hyejin; Wolf, Pavlina; Zhao, Wen-Ning; Norton, Stephanie; Haggarty, Stephen J.; Lloyd-Evans, Emyr; Cotman, Susan L.

    2015-01-01

    Abnormal accumulation of undigested macromolecules, often disease-specific, is a major feature of lysosomal and neurodegenerative disease and is frequently attributed to defective autophagy. The mechanistic underpinnings of the autophagy defects are the subject of intense research, which is aided by genetic disease models. To gain an improved understanding of the pathways regulating defective autophagy specifically in juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), a neurodegenerative disease of childhood, we developed and piloted a GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) screening assay to identify, in an unbiased fashion, genotype-sensitive small molecule autophagy modifiers, employing a JNCL neuronal cell model bearing the most common disease mutation in CLN3. Thapsigargin, a sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ pump inhibitor, reproducibly displayed significantly more activity in the mouse JNCL cells, an effect that was also observed in human-induced pluripotent stem cell-derived JNCL neural progenitor cells. The mechanism of thapsigargin sensitivity was Ca2+-mediated, and autophagosome accumulation in JNCL cells could be reversed by Ca2+ chelation. Interrogation of intracellular Ca2+ handling highlighted alterations in endoplasmic reticulum, mitochondrial, and lysosomal Ca2+ pools and in store-operated Ca2+ uptake in JNCL cells. These results further support an important role for the CLN3 protein in intracellular Ca2+ handling and in autophagic pathway flux and establish a powerful new platform for therapeutic screening. PMID:25878248

  2. Motion Estimation Based on Mutual Information and Adaptive Multi-Scale Thresholding.

    PubMed

    Xu, Rui; Taubman, David; Naman, Aous Thabit

    2016-03-01

    This paper proposes a new method of calculating a matching metric for motion estimation. The proposed method splits the information in the source images into multiple scale and orientation subbands, reduces the subband values to a binary representation via an adaptive thresholding algorithm, and uses mutual information to model the similarity of corresponding square windows in each image. A moving window strategy is applied to recover a dense estimated motion field whose properties are explored. The proposed matching metric is a sum of mutual information scores across space, scale, and orientation. This facilitates the exploitation of information diversity in the source images. Experimental comparisons are performed amongst several related approaches, revealing that the proposed matching metric is better able to exploit information diversity, generating more accurate motion fields. PMID:26742132

  3. Ant colony optimization image registration algorithm based on wavelet transform and mutual information

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Sun, Yanfeng; Zhai, Bing; Wang, Yiding

    2013-07-01

    This paper studies on the image registration of the medical images. Wavelet transform is adopted to decompose the medical images because the resolution of the medical image is high and the computational amount of the registration is large. Firstly, the low frequency sub-images are matched. Then source images are matched. The image registration was fulfilled by the ant colony optimization algorithm to search the extremum of the mutual information. The experiment result demonstrates the proposed approach can not only reduce calculation amount, but also skip from the local extremum during optimization process, and search the optimization value.

  4. A Method for Evaluating Tuning Functions of Single Neurons based on Mutual Information Maximization

    NASA Astrophysics Data System (ADS)

    Brostek, Lukas; Eggert, Thomas; Ono, Seiji; Mustari, Michael J.; Büttner, Ulrich; Glasauer, Stefan

    2011-03-01

    We introduce a novel approach for evaluation of neuronal tuning functions, which can be expressed by the conditional probability of observing a spike given any combination of independent variables. This probability can be estimated out of experimentally available data. By maximizing the mutual information between the probability distribution of the spike occurrence and that of the variables, the dependence of the spike on the input variables is maximized as well. We used this method to analyze the dependence of neuronal activity in cortical area MSTd on signals related to movement of the eye and retinal image movement.

  5. Mutual Adaptaion in Action

    ERIC Educational Resources Information Center

    Siskin, Leslie Santee

    2016-01-01

    Building on an expanded concept of mutual adaptation, this chapter explores a distinctive and successful aspect of International Baccalaureate's effort to scale up, as they moved to expand their programs and support services in Title I schools. Based on a three-year, mixed-methods study, it offers a case where we see not only local adaptations…

  6. Parallel Mutual Information Based Construction of Genome-Scale Networks on the Intel® Xeon Phi™ Coprocessor.

    PubMed

    Misra, Sanchit; Pamnany, Kiran; Aluru, Srinivas

    2015-01-01

    Construction of whole-genome networks from large-scale gene expression data is an important problem in systems biology. While several techniques have been developed, most cannot handle network reconstruction at the whole-genome scale, and the few that can, require large clusters. In this paper, we present a solution on the Intel Xeon Phi coprocessor, taking advantage of its multi-level parallelism including many x86-based cores, multiple threads per core, and vector processing units. We also present a solution on the Intel® Xeon® processor. Our solution is based on TINGe, a fast parallel network reconstruction technique that uses mutual information and permutation testing for assessing statistical significance. We demonstrate the first ever inference of a plant whole genome regulatory network on a single chip by constructing a 15,575 gene network of the plant Arabidopsis thaliana from 3,137 microarray experiments in only 22 minutes. In addition, our optimization for parallelizing mutual information computation on the Intel Xeon Phi coprocessor holds out lessons that are applicable to other domains. PMID:26451815

  7. Unbiased estimators for spatial distribution functions of classical fluids.

    PubMed

    Adib, Artur B; Jarzynski, Christopher

    2005-01-01

    We use a statistical-mechanical identity closely related to the familiar virial theorem, to derive unbiased estimators for spatial distribution functions of classical fluids. In particular, we obtain estimators for both the fluid density rho(r) in the vicinity of a fixed solute and the pair correlation g(r) of a homogeneous classical fluid. We illustrate the utility of our estimators with numerical examples, which reveal advantages over traditional histogram-based methods of computing such distributions. PMID:15638649

  8. An Advanced Temporal Credential-Based Security Scheme with Mutual Authentication and Key Agreement for Wireless Sensor Networks

    PubMed Central

    Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi

    2013-01-01

    Wireless sensor networks (WSNs) can be quickly and randomly deployed in any harsh and unattended environment and only authorized users are allowed to access reliable sensor nodes in WSNs with the aid of gateways (GWNs). Secure authentication models among the users, the sensor nodes and GWN are important research issues for ensuring communication security and data privacy in WSNs. In 2013, Xue et al. proposed a temporal-credential-based mutual authentication and key agreement scheme for WSNs. However, in this paper, we point out that Xue et al.'s scheme cannot resist stolen-verifier, insider, off-line password guessing, smart card lost problem and many logged-in users' attacks and these security weaknesses make the scheme inapplicable to practical WSN applications. To tackle these problems, we suggest a simple countermeasure to prevent proposed attacks while the other merits of Xue et al.'s authentication scheme are left unchanged. PMID:23887085

  9. An advanced temporal credential-based security scheme with mutual authentication and key agreement for wireless sensor networks.

    PubMed

    Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi

    2013-01-01

    Wireless sensor networks (WSNs) can be quickly and randomly deployed in any harsh and unattended environment and only authorized users are allowed to access reliable sensor nodes in WSNs with the aid of gateways (GWNs). Secure authentication models among the users, the sensor nodes and GWN are important research issues for ensuring communication security and data privacy in WSNs. In 2013, Xue et al. proposed a temporal-credential-based mutual authentication and key agreement scheme for WSNs. However, in this paper, we point out that Xue et al.'s scheme cannot resist stolen-verifier, insider, off-line password guessing, smart card lost problem and many logged-in users' attacks and these security weaknesses make the scheme inapplicable to practical WSN applications. To tackle these problems, we suggest a simple countermeasure to prevent proposed attacks while the other merits of Xue et al.'s authentication scheme are left unchanged. PMID:23887085

  10. Efficient and Unbiased Estimation of Population Size.

    PubMed

    Cruz, Marcos; Gómez, Domingo; Cruz-Orive, Luis M

    2015-01-01

    Population sizing from still aerial pictures is of wide applicability in ecological and social sciences. The problem is long standing because current automatic detection and counting algorithms are known to fail in most cases, and exhaustive manual counting is tedious, slow, difficult to verify and unfeasible for large populations. An alternative is to multiply population density with some reference area but, unfortunately, sampling details, handling of edge effects, etc., are seldom described. For the first time we address the problem using principles of geometric sampling. These principles are old and solid, but largely unknown outside the areas of three dimensional microscopy and stereology. Here we adapt them to estimate the size of any population of individuals lying on an essentially planar area, e.g. people, animals, trees on a savanna, etc. The proposed design is unbiased irrespective of population size, pattern, perspective artifacts, etc. The implementation is very simple-it is based on the random superimposition of coarse quadrat grids. Also, an objective error assessment is often lacking. For the latter purpose the quadrat counts are often assumed to be independent. We demonstrate that this approach can perform very poorly, and we propose (and check via Monte Carlo resampling) a new theoretical error prediction formula. As far as efficiency, counting about 50 (100) individuals in 20 quadrats, can yield relative standard errors of about 8% (5%) in typical cases. This fact effectively breaks the barrier hitherto imposed by the current lack of automatic face detection algorithms, because semiautomatic sampling and manual counting becomes an attractive option. PMID:26535587

  11. Efficient and Unbiased Estimation of Population Size

    PubMed Central

    Cruz, Marcos; Gómez, Domingo; Cruz-Orive, Luis M.

    2015-01-01

    Population sizing from still aerial pictures is of wide applicability in ecological and social sciences. The problem is long standing because current automatic detection and counting algorithms are known to fail in most cases, and exhaustive manual counting is tedious, slow, difficult to verify and unfeasible for large populations. An alternative is to multiply population density with some reference area but, unfortunately, sampling details, handling of edge effects, etc., are seldom described. For the first time we address the problem using principles of geometric sampling. These principles are old and solid, but largely unknown outside the areas of three dimensional microscopy and stereology. Here we adapt them to estimate the size of any population of individuals lying on an essentially planar area, e.g. people, animals, trees on a savanna, etc. The proposed design is unbiased irrespective of population size, pattern, perspective artifacts, etc. The implementation is very simple—it is based on the random superimposition of coarse quadrat grids. Also, an objective error assessment is often lacking. For the latter purpose the quadrat counts are often assumed to be independent. We demonstrate that this approach can perform very poorly, and we propose (and check via Monte Carlo resampling) a new theoretical error prediction formula. As far as efficiency, counting about 50 (100) individuals in 20 quadrats, can yield relative standard errors of about 8% (5%) in typical cases. This fact effectively breaks the barrier hitherto imposed by the current lack of automatic face detection algorithms, because semiautomatic sampling and manual counting becomes an attractive option. PMID:26535587

  12. Unbiased selective isolation of protein N-terminal peptides from complex proteome samples using phospho tagging (PTAG) and TiO(2)-based depletion.

    PubMed

    Mommen, Geert P M; van de Waterbeemd, Bas; Meiring, Hugo D; Kersten, Gideon; Heck, Albert J R; de Jong, Ad P J M

    2012-09-01

    A positional proteomics strategy for global N-proteome analysis is presented based on phospho tagging (PTAG) of internal peptides followed by depletion by titanium dioxide (TiO(2)) affinity chromatography. Therefore, N-terminal and lysine amino groups are initially completely dimethylated with formaldehyde at the protein level, after which the proteins are digested and the newly formed internal peptides modified with the PTAG reagent glyceraldhyde-3-phosphate in nearly perfect yields (> 99%). The resulting phosphopeptides are depleted through binding onto TiO(2), keeping exclusively a set of N-acetylated and/or N-dimethylated terminal peptides for analysis by liquid chromatography-tandem MS. Analysis of peptides derivatized with differentially labeled isotopic analogs of the PTAG reagent revealed a high depletion efficiency (> 95%). The method enabled identification of 753 unique N-terminal peptides (428 proteins) in N. meningitidis and 928 unique N-terminal peptides (572 proteins) in S. cerevisiae. These included verified neo-N termini from subcellular-relocalized membrane and mitochondrial proteins. The presented PTAG approach is therefore a novel, versatile, and robust method for mass spectrometry-based N-proteome analysis and identification of protease-generated cleavage products. PMID:22729381

  13. Mutual information-based template matching scheme for detection of breast masses: from mammography to digital breast tomosynthesis.

    PubMed

    Mazurowski, Maciej A; Lo, Joseph Y; Harrawood, Brian P; Tourassi, Georgia D

    2011-10-01

    Development of a computational decision aid for a new medical imaging modality typically is a long and complicated process. It consists of collecting data in the form of images and annotations, development of image processing and pattern recognition algorithms for analysis of the new images and finally testing of the resulting system. Since new imaging modalities are developed more rapidly than ever before, any effort for decreasing the time and cost of this development process could result in maximizing the benefit of the new imaging modality to patients by making the computer aids quickly available to radiologists that interpret the images. In this paper, we make a step in this direction and investigate the possibility of translating the knowledge about the detection problem from one imaging modality to another. Specifically, we present a computer-aided detection (CAD) system for mammographic masses that uses a mutual information-based template matching scheme with intelligently selected templates. We presented principles of template matching with mutual information for mammography before. In this paper, we present an implementation of those principles in a complete computer-aided detection system. The proposed system, through an automatic optimization process, chooses the most useful templates (mammographic regions of interest) using a large database of previously collected and annotated mammograms. Through this process, the knowledge about the task of detecting masses in mammograms is incorporated in the system. Then, we evaluate whether our system developed for screen-film mammograms can be successfully applied not only to other mammograms but also to digital breast tomosynthesis (DBT) reconstructed slices without adding any DBT cases for training. Our rationale is that since mutual information is known to be a robust inter-modality image similarity measure, it has high potential of transferring knowledge between modalities in the context of the mass detection

  14. Unbiased Categorical Classification of Pediatric Sleep Disordered Breathing

    PubMed Central

    Spruyt, Karen; Verleye, Gino; Gozal, David

    2010-01-01

    Study Objectives: To classify pediatric sleep disordered breathing (SDB) using unbiased approaches. In children, decisions regarding severity and treatment of SDB are conducted solely based on empirical observations. Although recognizable entities clearly exist under the SDB spectrum, neither the number of SDB categories nor their specific criteria have been critically defined. Design: retrospective cohort analysis and random prospective cohort Setting: community and clinical sample Patients or Participants: Urban 5- to 9-year-old community children undergoing overnight sleep study (NPSG), and a comparable prospectively recruited clinical SDB sample. Interventions: n/a Measurements and Results: Principal component analysis was used to identify the uniqueness of the polysomnographically derived measures that are routinely used in clinical settings: apnea-hypopnea index, apnea index, obstructive apnea index, nadir SpO2, spontaneous arousal index and respiratory arousal index. These measures were then incorporated using unbiased data mining approaches to further characterize and discriminate across categorical phenotypes. Of 1,133 subjects, 52.8% were habitual snorers. Six categorical phenotypes clustered without any a priori hypothesis. Secondly, a non-hierarchical model that incorporated 6 NPSG-derived measures enabled unbiased identification of algorithms that predicted these 6 severity-based clusters. Thirdly, a hierarchical model was developed and performed well on all severity-based clusters. Classification and predictive models were subsequently cross-validated statistically as well as clinically, using 2 additional datasets that included 259 subjects. Modeling reached ∼93% accuracy in cluster assignment. Conclusions: Data-driven analysis of conventional NPSG-derived indices identified 6 distinct clusters ranging from a cluster with normal indices toward clusters with more abnormal indices. Categorical assignment of individual cases to any of such clusters

  15. Design of a mutual authentication based on NTRUsign with a perturbation and inherent multipoint control protocol frames in an Ethernet-based passive optical network

    NASA Astrophysics Data System (ADS)

    Yin, Aihan; Ding, Yisheng

    2014-11-01

    Identity-related security issues inherently present in passive optical networks (PON) still exist in the current (1G) and next-generation (10G) Ethernet-based passive optical network (EPON) systems. We propose a mutual authentication scheme that integrates an NTRUsign digital signature algorithm with inherent multipoint control protocol (MPCP) frames over an EPON system between the optical line terminal (OLT) and optical network unit (ONU). Here, a primitive NTRUsign algorithm is significantly modified through the use of a new perturbation so that it can be effectively used for simultaneously completing signature and authentication functions on the OLT and the ONU sides. Also, in order to transmit their individual sensitive messages, which include public key, signature, and random value and so forth, to each other, we redefine three unique frames according to MPCP format frame. These generated messages can be added into the frames and delivered to each other, allowing the OLT and the ONU to go ahead with a mutual identity authentication process to verify their legal identities. Our simulation results show that this proposed scheme performs very well in resisting security attacks and has low influence on the registration efficiency to to-be-registered ONUs. A performance comparison with traditional authentication algorithms is also presented. To the best of our knowledge, no detailed design of mutual authentication in EPON can be found in the literature up to now.

  16. A Support Method with Changeable Training Strategies Based on Mutual Adaptation between a Ubiquitous Pet and a Learner

    NASA Astrophysics Data System (ADS)

    Ye, Xianzhi; Jing, Lei; Kansen, Mizuo; Wang, Junbo; Ota, Kaoru; Cheng, Zixue

    With the progress of ubiquitous technology, ubiquitous learning presents new opportunities to learners. Situations of a learner can be grasped through analyzing the learner's actions collected by sensors, RF-IDs, or cameras in order to provide support at proper time, proper place, and proper situation. Training for acquiring skills and enhancing physical abilities through exercise and experience in the real world is an important domain in u-learning. A training program may last for several days and has one or more training units (exercises) for a day. A learner's performance in a unit is considered as short term state. The performance in a series of units may change with patterns: progress, plateau, and decline. Long term state in a series of units is accumulatively computed based on short term states. In a learning/training program, it is necessary to apply different support strategies to adapt to different states of the learner. Adaptation in learning support is significant, because a learner loses his/her interests easily without adaptation. Systems with the adaptive support usually provide stimulators to a learner, and a learner can have a great motivation in learning at beginning. However, when the stimulators reach some levels, the learner may lose his/her motivation, because the long term state of the learner changes dynamically, which means a progress state may change to a plateau state or a decline state. In different long term learning states, different types of stimulators are needed. However, the stimulators and advice provided by the existing systems are monotonic without changeable support strategies. We propose a mutual adaptive support. The mutual adaptation means each of the system and the learner has their own states. On one hand, the system tries to change its state to adapt to the learner's state for providing adaptive support. On the other hand, the learner can change its performance following the advice given based on the state of the system

  17. Reconstructing input for artificial neural networks based on embedding theory and mutual information to simulate soil pore water salinity in tidal floodplain

    NASA Astrophysics Data System (ADS)

    Zheng, Fawen; Wan, Yongshan; Song, Keunyea; Sun, Detong; Hedgepeth, Marion

    2016-01-01

    Soil pore water salinity plays an important role in the distribution of vegetation and biogeochemical processes in coastal floodplain ecosystems. In this study, artificial neural networks (ANNs) were applied to simulate the pore water salinity of a tidal floodplain in Florida. We present an approach based on embedding theory with mutual information to reconstruct ANN model input time series from one system state variable. Mutual information between system output and input was computed and the local minimum mutual information points were used to determine a time lag vector for time series embedding and reconstruction, with which the mutual information weighted average method was developed to compute the components of reconstructed time series. The optimal embedding dimension was obtained by optimizing model performance. The method was applied to simulate soil pore water salinity dynamics at 12 probe locations in the tidal floodplain influenced by saltwater intrusion using 4 years (2005-2008) data, in which adjacent river water salinity was used to reconstruct model input. The simulated electrical conductivity of the pore water showed close agreement with field observations (RMSE and ), suggesting the reconstructed input by the proposed approach provided adequate input information for ANN modeling. Multiple linear regression model, partial mutual information algorithm for input variable selection, k-NN algorithm, and simple time delay embedding were also used to further verify the merit of the proposed approach.

  18. A hash based mutual RFID tag authentication protocol in telecare medicine information system.

    PubMed

    Srivastava, Keerti; Awasthi, Amit K; Kaul, Sonam D; Mittal, R C

    2015-01-01

    Radio Frequency Identification (RFID) is a technology which has multidimensional applications to reduce the complexity of today life. Everywhere, like access control, transportation, real-time inventory, asset management and automated payment systems etc., RFID has its enormous use. Recently, this technology is opening its wings in healthcare environments, where potential applications include patient monitoring, object traceability and drug administration systems etc. In this paper, we propose a secure RFID-based protocol for the medical sector. This protocol is based on hash operation with synchronized secret. The protocol is safe against active and passive attacks such as forgery, traceability, replay and de-synchronization attack. PMID:25491577

  19. Mutual exclusion

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1991-01-01

    Almost all computers today operate as part of a network, where they assist people in coordinating actions. Sometimes what appears to be a single computer is actually a network of cooperating computers; e.g., some supercomputers consist of many processors operating in parallel and exchanging synchronization signals. One of the most fundamental requirements in all these systems is that certain operations be indivisible: the steps of one must not be interleaved with the steps of another. Two approaches were designed to implement this requirement, one based on central locks and the other on distributed order tickets. Practicing scientists and engineers need to come to be familiar with these methods.

  20. Using a Search Engine-Based Mutually Reinforcing Approach to Assess the Semantic Relatedness of Biomedical Terms

    PubMed Central

    Hsu, Yi-Yu; Chen, Hung-Yu; Kao, Hung-Yu

    2013-01-01

    Background Determining the semantic relatedness of two biomedical terms is an important task for many text-mining applications in the biomedical field. Previous studies, such as those using ontology-based and corpus-based approaches, measured semantic relatedness by using information from the structure of biomedical literature, but these methods are limited by the small size of training resources. To increase the size of training datasets, the outputs of search engines have been used extensively to analyze the lexical patterns of biomedical terms. Methodology/Principal Findings In this work, we propose the Mutually Reinforcing Lexical Pattern Ranking (ReLPR) algorithm for learning and exploring the lexical patterns of synonym pairs in biomedical text. ReLPR employs lexical patterns and their pattern containers to assess the semantic relatedness of biomedical terms. By combining sentence structures and the linking activities between containers and lexical patterns, our algorithm can explore the correlation between two biomedical terms. Conclusions/Significance The average correlation coefficient of the ReLPR algorithm was 0.82 for various datasets. The results of the ReLPR algorithm were significantly superior to those of previous methods. PMID:24348899

  1. MINT: Mutual Information Based Transductive Feature Selection for Genetic Trait Prediction.

    PubMed

    He, Dan; Rish, Irina; Haws, David; Parida, Laxmi

    2016-01-01

    Whole genome prediction of complex phenotypic traits using high-density genotyping arrays has attracted a lot of attention, as it is relevant to the fields of plant and animal breeding and genetic epidemiology. Since the number of genotypes is generally much bigger than the number of samples, predictive models suffer from the curse of dimensionality. The curse of dimensionality problem not only affects the computational efficiency of a particular genomic selection method, but can also lead to a poor performance, mainly due to possible overfitting, or un-informative features. In this work, we propose a novel transductive feature selection method, called MINT, which is based on the MRMR (Max-Relevance and Min-Redundancy) criterion. We apply MINT on genetic trait prediction problems and show that, in general, MINT is a better feature selection method than the state-of-the-art inductive method MRMR. PMID:27295642

  2. Cross-kingdom chemical communication drives a heritable, mutually beneficial prion-based transformations of metabolism

    PubMed Central

    Walker, Gordon A.; Datta, Manoshi S.; Ung, W. Lloyd; Lancaster, Alex K.; Chang, Amelia; Newby, Gregory A.; Weitz, David A.; Bisson, Linda F.; Lindquist, Susan

    2015-01-01

    SUMMARY In experimental science, organisms are usually studied in isolation, but in the wild they compete and cooperate in complex communities. We report a system for cross-kingdom communication by which bacteria heritably transform yeast metabolism. An ancient biological circuit blocks yeast from using other carbon sources in the presence of glucose. [GAR+], a protein-based epigenetic element, allows yeast to circumvent this glucose repression and use multiple carbon sources in the presence of glucose. Some bacteria secrete a chemical factor that induces [GAR+]. [GAR+] is advantageous to bacteria because yeast cells make less ethanol, and is advantageous to yeast because their growth and long-term viability is improved in complex carbon sources. This cross-kingdom communication is broadly conserved, providing a compelling argument for its adaptive value. By heritably transforming growth and survival strategies in response to the selective pressures of life in a biological community, [GAR+] presents a unique example of Lamarckian inheritance. PMID:25171409

  3. Reinforcement-based decision making in corticostriatal circuits: mutual constraints by neurocomputational and diffusion models.

    PubMed

    Ratcliff, Roger; Frank, Michael J

    2012-05-01

    In this letter, we examine the computational mechanisms of reinforce-ment-based decision making. We bridge the gap across multiple levels of analysis, from neural models of corticostriatal circuits-the basal ganglia (BG) model (Frank, 2005 , 2006 ) to simpler but mathematically tractable diffusion models of two-choice decision making. Specifically, we generated simulated data from the BG model and fit the diffusion model (Ratcliff, 1978 ) to it. The standard diffusion model fits underestimated response times under conditions of high response and reinforcement conflict. Follow-up fits showed good fits to the data both by increasing nondecision time and by raising decision thresholds as a function of conflict and by allowing this threshold to collapse with time. This profile captures the role and dynamics of the subthalamic nucleus in BG circuitry, and as such, parametric modulations of projection strengths from this nucleus were associated with parametric increases in decision boundary and its modulation by conflict. We then present data from a human reinforcement learning experiment involving decisions with low- and high-reinforcement conflict. Again, the standard model failed to fit the data, but we found that two variants similar to those that fit the BG model data fit the experimental data, thereby providing a convergence of theoretical accounts of complex interactive decision-making mechanisms consistent with available data. This work also demonstrates how to make modest modifications to diffusion models to summarize core computations of the BG model. The result is a better fit and understanding of reinforcement-based choice data than that which would have occurred with either model alone. PMID:22295983

  4. A web-based care-requiring client and Home Helper mutual support system.

    PubMed

    Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Hahn, Allen W; Caldwell, W Morton

    2005-01-01

    For the improved efficiency of home care of the elderly, a web-based system has been developed to enable faster communications between care-requiring clients, their Home Helper and the care manager. Changes to care items, such as cooking, bathing, washing, cleaning and shopping are usually requested by the elderly client over the telephone. However, the care central office often requires 24 hours to process and respond to such spoken requests. The system we have developed consists of Internet client computers with liquid crystal input tablets, wireless Internet Java enabled mobile phones and a central office server that yields almost instant communication. The care clients enter requests on the liquid crystal tablet at their home and then their computer sends these requests to the server at the Home Helper central office. The server automatically creates a new file of the requested items, and then immediately transfers them to the care manager and Home Helper's mobile phone. With this non-vocal and paperless system, the care-requiring clients, who can easily operate the liquid crystal tablet, can very quickly communicate their needed care change requests to their Home Helper. PMID:15850098

  5. [Construction and simplification of the calibration model for spectral analysis of fuel oil properties based on mutual information method].

    PubMed

    Hao, Yong; Sun, Xu-dong; Cai, Li-jun; Liu, Yan-de

    2012-01-01

    Near infrared diffuse reflectance (NIRS) and ultraviolet (UV) spectral analysis were adopted for quantitative determination of octane number and monoaromatics in fuel oil. Partial least squares regression (PLSR) was used for construction of vibrational spectral calibration models. Variables selection strategy based on mutual information (MI) theory was introduced to optimize the models for improving the precision and reducing the complexity. The results indicate that MI-PLSR method can effectively improve the predictive ability of the models and simplify them. For octane number models, the root mean square error of prediction (RMSEP) and the number of calibration variables were reduced from 0.288 and 401 to 0.111 and 112, respectively, and correlation coefficient (R) was improved from 0.985 to 0.998. For monoaromatics models, RMSEP and the number of calibration variables were reduced from 0.753 and 572 to 0.478 and 37, respectively, and R was improved from 0.996 to 0.998. Vibrational spectral analysis combined with MI-PLSR method can be used for quantitative analysis of fuel oil properties, and improve the cost-effectiveness. PMID:22497153

  6. Comparison of - and Mutual Informaton Based Calibration of Terrestrial Laser Scanner and Digital Camera for Deformation Monitoring

    NASA Astrophysics Data System (ADS)

    Omidalizarandi, M.; Neumann, I.

    2015-12-01

    In the current state-of-the-art, geodetic deformation analysis of natural and artificial objects (e.g. dams, bridges,...) is an ongoing research in both static and kinematic mode and has received considerable interest by researchers and geodetic engineers. In this work, due to increasing the accuracy of geodetic deformation analysis, a terrestrial laser scanner (TLS; here the Zoller+Fröhlich IMAGER 5006) and a high resolution digital camera (Nikon D750) are integrated to complementarily benefit from each other. In order to optimally combine the acquired data of the hybrid sensor system, a highly accurate estimation of the extrinsic calibration parameters between TLS and digital camera is a vital preliminary step. Thus, the calibration of the aforementioned hybrid sensor system can be separated into three single calibrations: calibration of the camera, calibration of the TLS and extrinsic calibration between TLS and digital camera. In this research, we focus on highly accurate estimating extrinsic parameters between fused sensors and target- and targetless (mutual information) based methods are applied. In target-based calibration, different types of observations (image coordinates, TLS measurements and laser tracker measurements for validation) are utilized and variance component estimation is applied to optimally assign adequate weights to the observations. Space resection bundle adjustment based on the collinearity equations is solved using Gauss-Markov and Gauss-Helmert model. Statistical tests are performed to discard outliers and large residuals in the adjustment procedure. At the end, the two aforementioned approaches are compared and advantages and disadvantages of them are investigated and numerical results are presented and discussed.

  7. SU-E-J-132: Automated Segmentation with Post-Registration Atlas Selection Based On Mutual Information

    SciTech Connect

    Ren, X; Gao, H; Sharp, G

    2015-06-15

    Purpose: The delineation of targets and organs-at-risk is a critical step during image-guided radiation therapy, for which manual contouring is the gold standard. However, it is often time-consuming and may suffer from intra- and inter-rater variability. The purpose of this work is to investigate the automated segmentation. Methods: The automatic segmentation here is based on mutual information (MI), with the atlas from Public Domain Database for Computational Anatomy (PDDCA) with manually drawn contours.Using dice coefficient (DC) as the quantitative measure of segmentation accuracy, we perform leave-one-out cross-validations for all PDDCA images sequentially, during which other images are registered to each chosen image and DC is computed between registered contour and ground truth. Meanwhile, six strategies, including MI, are selected to measure the image similarity, with MI to be the best. Then given a target image to be segmented and an atlas, automatic segmentation consists of: (a) the affine registration step for image positioning; (b) the active demons registration method to register the atlas to the target image; (c) the computation of MI values between the deformed atlas and the target image; (d) the weighted image fusion of three deformed atlas images with highest MI values to form the segmented contour. Results: MI was found to be the best among six studied strategies in the sense that it had the highest positive correlation between similarity measure (e.g., MI values) and DC. For automated segmentation, the weighted image fusion of three deformed atlas images with highest MI values provided the highest DC among four proposed strategies. Conclusion: MI has the highest correlation with DC, and therefore is an appropriate choice for post-registration atlas selection in atlas-based segmentation. Xuhua Ren and Hao Gao were partially supported by the NSFC (#11405105), the 973 Program (#2015CB856000) and the Shanghai Pujiang Talent Program (#14PJ1404500)

  8. Unbiased sampling of lattice Hamilton path ensembles

    NASA Astrophysics Data System (ADS)

    Mansfield, Marc L.

    2006-10-01

    Hamilton paths, or Hamiltonian paths, are walks on a lattice which visit each site exactly once. They have been proposed as models of globular proteins and of compact polymers. A previously published algorithm [Mansfield, Macromolecules 27, 5924 (1994)] for sampling Hamilton paths on simple square and simple cubic lattices is tested for bias and for efficiency. Because the algorithm is a Metropolis Monte Carlo technique obviously satisfying detailed balance, we need only demonstrate ergodicity to ensure unbiased sampling. Two different tests for ergodicity (exact enumeration on small lattices, nonexhaustive enumeration on larger lattices) demonstrate ergodicity unequivocally for small lattices and provide strong support for ergodicity on larger lattices. Two other sampling algorithms [Ramakrishnan et al., J. Chem. Phys. 103, 7592 (1995); Lua et al., Polymer 45, 717 (2004)] are both known to produce biases on both 2×2×2 and 3×3×3 lattices, but it is shown here that the current algorithm gives unbiased sampling on these same lattices. Successive Hamilton paths are strongly correlated, so that many iterations are required between statistically independent samples. Rules for estimating the number of iterations needed to dissipate these correlations are given. However, the iteration time is so fast that the efficiency is still very good except on extremely large lattices. For example, even on lattices of total size 10×10×10 we are able to generate tens of thousands of uncorrelated Hamilton paths per hour of CPU time.

  9. Two Phase Non-Rigid Multi-Modal Image Registration Using Weber Local Descriptor-Based Similarity Metrics and Normalized Mutual Information

    PubMed Central

    Yang, Feng; Ding, Mingyue; Zhang, Xuming; Wu, Yi; Hu, Jiani

    2013-01-01

    Non-rigid multi-modal image registration plays an important role in medical image processing and analysis. Existing image registration methods based on similarity metrics such as mutual information (MI) and sum of squared differences (SSD) cannot achieve either high registration accuracy or high registration efficiency. To address this problem, we propose a novel two phase non-rigid multi-modal image registration method by combining Weber local descriptor (WLD) based similarity metrics with the normalized mutual information (NMI) using the diffeomorphic free-form deformation (FFD) model. The first phase aims at recovering the large deformation component using the WLD based non-local SSD (wldNSSD) or weighted structural similarity (wldWSSIM). Based on the output of the former phase, the second phase is focused on getting accurate transformation parameters related to the small deformation using the NMI. Extensive experiments on T1, T2 and PD weighted MR images demonstrate that the proposed wldNSSD-NMI or wldWSSIM-NMI method outperforms the registration methods based on the NMI, the conditional mutual information (CMI), the SSD on entropy images (ESSD) and the ESSD-NMI in terms of registration accuracy and computation efficiency. PMID:23765270

  10. Obtaining an unbiased redshift distribution for submm galaxies

    NASA Astrophysics Data System (ADS)

    Ivison, Rob; Norris, Ray; Feain, Ilana; Huynh, Minh; Smail, Ian; Thomson, Alasdair

    2009-07-01

    We request 36hr with ATCA to test a new method for determining an unbiased redshift distribution for submm galaxies (SMGs) - a critical parameter capable of breaking degeneracies in galaxy evolution models. Our method is based on the expectation that dusty ULIRGs will exhibit maser activity similar to that observed in other IR-luminous AGN. As well as determining redshifts, detections will allow us to estimate the mass of the central black hole (to compare with X-ray-based estimates), to pinpoint the maser relative to the synchrotron emission, and to explore any correlation between L(FIR) and L(H2O). The key to our project is the largest deep submm survey undertaken thus far - LESS - in the Extended Chandra Deep Field South. We propose to piggyback on the Huynh et al. 5-GHz survey of ECDFS, going 2.3x deeper in two pointings centred on over-densities of bright SMGs.

  11. Unbiased Deep Sequencing of RNA Viruses from Clinical Samples.

    PubMed

    Matranga, Christian B; Gladden-Young, Adrianne; Qu, James; Winnicki, Sarah; Nosamiefan, Dolo; Levin, Joshua Z; Sabeti, Pardis C

    2016-01-01

    Here we outline a next-generation RNA sequencing protocol that enables de novo assemblies and intra-host variant calls of viral genomes collected from clinical and biological sources. The method is unbiased and universal; it uses random primers for cDNA synthesis and requires no prior knowledge of the viral sequence content. Before library construction, selective RNase H-based digestion is used to deplete unwanted RNA - including poly(rA) carrier and ribosomal RNA - from the viral RNA sample. Selective depletion improves both the data quality and the number of unique reads in viral RNA sequencing libraries. Moreover, a transposase-based 'tagmentation' step is used in the protocol as it reduces overall library construction time. The protocol has enabled rapid deep sequencing of over 600 Lassa and Ebola virus samples-including collections from both blood and tissue isolates-and is broadly applicable to other microbial genomics studies. PMID:27403729

  12. Unbiased approaches to biomarker discovery in neurodegenerative diseases

    PubMed Central

    Chen-Plotkin, Alice S.

    2014-01-01

    Neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and frontotemporal dementia have several important features in common. They are progressive, they affect a relatively inaccessible organ, and we have no disease-modifying therapies for them. For these brain-based diseases, current diagnosis and evaluation of disease severity rely almost entirely on clinical examination, which may only be a rough approximation of disease state. Thus, the development of biomarkers – objective, relatively easily measured and precise indicators of pathogenic processes – could improve patient care and accelerate therapeutic discovery. Yet existing, rigorously tested neurodegenerative disease biomarkers are few, and even fewer biomarkers have translated into clinical use. To find new biomarkers for these diseases, an unbiased, high-throughput screening approach may be needed. In this review, I will describe the potential utility of such an approach to biomarker discovery, using Parkinson’s disease as a case example. PMID:25442938

  13. Neurostereology protocol for unbiased quantification of neuronal injury and neurodegeneration

    PubMed Central

    Golub, Victoria M.; Brewer, Jonathan; Wu, Xin; Kuruba, Ramkumar; Short, Jenessa; Manchi, Maunica; Swonke, Megan; Younus, Iyan; Reddy, Doodipala Samba

    2015-01-01

    Neuronal injury and neurodegeneration are the hallmark pathologies in a variety of neurological conditions such as epilepsy, stroke, traumatic brain injury, Parkinson’s disease and Alzheimer’s disease. Quantification of absolute neuron and interneuron counts in various brain regions is essential to understand the impact of neurological insults or neurodegenerative disease progression in animal models. However, conventional qualitative scoring-based protocols are superficial and less reliable for use in studies of neuroprotection evaluations. Here, we describe an optimized stereology protocol for quantification of neuronal injury and neurodegeneration by unbiased counting of neurons and interneurons. Every 20th section in each series of 20 sections was processed for NeuN(+) total neuron and parvalbumin(+) interneuron immunostaining. The sections that contain the hippocampus were then delineated into five reliably predefined subregions. Each region was separately analyzed with a microscope driven by the stereology software. Regional tissue volume was determined by using the Cavalieri estimator, as well as cell density and cell number were determined by using the optical disector and optical fractionator. This protocol yielded an estimate of 1.5 million total neurons and 0.05 million PV(+) interneurons within the rat hippocampus. The protocol has greater predictive power for absolute counts as it is based on 3D features rather than 2D images. The total neuron counts were consistent with literature values from sophisticated systems, which are more expensive than our stereology system. This unbiased stereology protocol allows for sensitive, medium-throughput counting of total neurons in any brain region, and thus provides a quantitative tool for studies of neuronal injury and neurodegeneration in a variety of acute brain injury and chronic neurological models. PMID:26582988

  14. Why mutual helping in most natural systems is neither conflict-free nor based on maximal conflict.

    PubMed

    Bshary, Redouan; Zuberbühler, Klaus; van Schaik, Carel P

    2016-02-01

    Mutual helping for direct benefits can be explained by various game theoretical models, which differ mainly in terms of the underlying conflict of interest between two partners. Conflict is minimal if helping is self-serving and the partner benefits as a by-product. In contrast, conflict is maximal if partners are in a prisoner's dilemma with both having the pay-off-dominant option of not returning the other's investment. Here, we provide evolutionary and ecological arguments for why these two extremes are often unstable under natural conditions and propose that interactions with intermediate levels of conflict are frequent evolutionary endpoints. We argue that by-product helping is prone to becoming an asymmetric investment game since even small variation in by-product benefits will lead to the evolution of partner choice, leading to investments by the chosen class. Second, iterated prisoner's dilemmas tend to take place in stable social groups where the fitness of partners is interdependent, with the effect that a certain level of helping is self-serving. In sum, intermediate levels of mutual helping are expected in nature, while efficient partner monitoring may allow reaching higher levels. PMID:26729931

  15. Smooth-Threshold Multivariate Genetic Prediction with Unbiased Model Selection.

    PubMed

    Ueki, Masao; Tamiya, Gen

    2016-04-01

    We develop a new genetic prediction method, smooth-threshold multivariate genetic prediction, using single nucleotide polymorphisms (SNPs) data in genome-wide association studies (GWASs). Our method consists of two stages. At the first stage, unlike the usual discontinuous SNP screening as used in the gene score method, our method continuously screens SNPs based on the output from standard univariate analysis for marginal association of each SNP. At the second stage, the predictive model is built by a generalized ridge regression simultaneously using the screened SNPs with SNP weight determined by the strength of marginal association. Continuous SNP screening by the smooth thresholding not only makes prediction stable but also leads to a closed form expression of generalized degrees of freedom (GDF). The GDF leads to the Stein's unbiased risk estimation (SURE), which enables data-dependent choice of optimal SNP screening cutoff without using cross-validation. Our method is very rapid because computationally expensive genome-wide scan is required only once in contrast to the penalized regression methods including lasso and elastic net. Simulation studies that mimic real GWAS data with quantitative and binary traits demonstrate that the proposed method outperforms the gene score method and genomic best linear unbiased prediction (GBLUP), and also shows comparable or sometimes improved performance with the lasso and elastic net being known to have good predictive ability but with heavy computational cost. Application to whole-genome sequencing (WGS) data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) exhibits that the proposed method shows higher predictive power than the gene score and GBLUP methods. PMID:26947266

  16. Evolution of mutualism between species

    SciTech Connect

    Post, W.M.; Travis, C.C.; DeAngelis, D.L.

    1980-01-01

    Recent theoretical work on mutualism, the interaction between species populations that is mutually beneficial, is reviewed. Several ecological facts that should be addressed in the construction of dynamic models for mutualism are examined. Basic terminology is clarified. (PSB)

  17. Behavioral Ecology: Manipulative Mutualism.

    PubMed

    Hughes, David P

    2015-09-21

    A new study reveals that an apparent mutualism between lycaenid caterpillars and their attendant ants may not be all it seems, as the caterpillars produce secretions that modify the brains and behavior of their attendant ants. PMID:26394105

  18. The joint effect of ethnicity and gender on occupational segregation. An approach based on the Mutual Information Index.

    PubMed

    Guinea-Martin, Daniel; Mora, Ricardo; Ruiz-Castillo, Javier

    2015-01-01

    In this article, we study the effects of ethnicity and gender on occupational segregation. Traditionally, researchers have examined the two sources of segregation separately. In contrast, we measure their joint effect by applying a multigroup segregation index-the Mutual Information or M index-to the product of the seven ethnic groups and two genders distinguished in our 2001 Census data for England and Wales. We exploit M's additive decomposability property to pose the following two questions: (i) Is there an interaction effect? (ii) How much does each source contribute to occupational segregation, controlling for the effect of the other? Although the role of ethnicity is non-negligible in the areas where minorities are concentrated, our findings confirm the greater importance of gender over ethnicity as a source of segregation. Moreover, we find a small "dwindling" interaction effect between the two sources of segregation: ethnicity slightly weakens the segregating power of gender and vice versa. PMID:25432611

  19. Estimating mutual information.

    PubMed

    Kraskov, Alexander; Stögbauer, Harald; Grassberger, Peter

    2004-06-01

    We present two classes of improved estimators for mutual information M(X,Y), from samples of random points distributed according to some joint probability density mu(x,y). In contrast to conventional estimators based on binnings, they are based on entropy estimates from k -nearest neighbor distances. This means that they are data efficient (with k=1 we resolve structures down to the smallest possible scales), adaptive (the resolution is higher where data are more numerous), and have minimal bias. Indeed, the bias of the underlying entropy estimates is mainly due to nonuniformity of the density at the smallest resolved scale, giving typically systematic errors which scale as functions of k/N for N points. Numerically, we find that both families become exact for independent distributions, i.e. the estimator M(X,Y) vanishes (up to statistical fluctuations) if mu(x,y)=mu(x)mu(y). This holds for all tested marginal distributions and for all dimensions of x and y. In addition, we give estimators for redundancies between more than two random variables. We compare our algorithms in detail with existing algorithms. Finally, we demonstrate the usefulness of our estimators for assessing the actual independence of components obtained from independent component analysis (ICA), for improving ICA, and for estimating the reliability of blind source separation. PMID:15244698

  20. A Simplified model of mutually inhibitory sleep-active and wake-active neuronal populations employing a noise-based switching mechanism.

    PubMed

    Patel, Mainak

    2016-04-01

    Infant rats switch randomly between the sleeping and waking states; during early infancy (up to postnatal day 8), sleep and wake bouts are random, brief (with means on the order of several seconds) and exponentially distributed, with the length of a particular bout independent of the length of prior bouts. As the rat ages during this early period, mean sleep and wake bout lengths gradually increase, though sleep and wake bouts remain exponentially distributed. Additionally, sleep and wake bouts are regulated independently of each other - alterations in the development of sleep (wake) bouts has no impact on the regulation wake (sleep) bouts. Sleep and wake bout behavior is associated with the activity of mutually inhibitory sleep-active and wake-active brainstem populations. In this work, I employ a simplified biophysical model of two mutually inhibitory populations consisting of ten integrate-and-fire neurons each and a noise-based switching mechanism. I show that such a noise-based switching mechanism naturally accounts for the experimentally observed features of sleep-wake switching during early infancy - random alternating activity bouts occur as a consequence of noise (provided inhibition is strong relative to excitation), bout durations are exponential (due to a lack of memory within the system), and cross-population inhibition or intrapopulation excitatory coupling provide mechanisms for changing and independently regulated sleep and wake bout means. PMID:26802484

  1. MIrExpress: A Database for Gene Coexpression Correlation in Immune Cells Based on Mutual Information and Pearson Correlation

    PubMed Central

    Wang, Luman; Mo, Qiaochu; Wang, Jianxin

    2015-01-01

    Most current gene coexpression databases support the analysis for linear correlation of gene pairs, but not nonlinear correlation of them, which hinders precisely evaluating the gene-gene coexpression strengths. Here, we report a new database, MIrExpress, which takes advantage of the information theory, as well as the Pearson linear correlation method, to measure the linear correlation, nonlinear correlation, and their hybrid of cell-specific gene coexpressions in immune cells. For a given gene pair or probe set pair input by web users, both mutual information (MI) and Pearson correlation coefficient (r) are calculated, and several corresponding values are reported to reflect their coexpression correlation nature, including MI and r values, their respective rank orderings, their rank comparison, and their hybrid correlation value. Furthermore, for a given gene, the top 10 most relevant genes to it are displayed with the MI, r, or their hybrid perspective, respectively. Currently, the database totally includes 16 human cell groups, involving 20,283 human genes. The expression data and the calculated correlation results from the database are interactively accessible on the web page and can be implemented for other related applications and researches. PMID:26881263

  2. MIrExpress: A Database for Gene Coexpression Correlation in Immune Cells Based on Mutual Information and Pearson Correlation.

    PubMed

    Wang, Luman; Mo, Qiaochu; Wang, Jianxin

    2015-01-01

    Most current gene coexpression databases support the analysis for linear correlation of gene pairs, but not nonlinear correlation of them, which hinders precisely evaluating the gene-gene coexpression strengths. Here, we report a new database, MIrExpress, which takes advantage of the information theory, as well as the Pearson linear correlation method, to measure the linear correlation, nonlinear correlation, and their hybrid of cell-specific gene coexpressions in immune cells. For a given gene pair or probe set pair input by web users, both mutual information (MI) and Pearson correlation coefficient (r) are calculated, and several corresponding values are reported to reflect their coexpression correlation nature, including MI and r values, their respective rank orderings, their rank comparison, and their hybrid correlation value. Furthermore, for a given gene, the top 10 most relevant genes to it are displayed with the MI, r, or their hybrid perspective, respectively. Currently, the database totally includes 16 human cell groups, involving 20,283 human genes. The expression data and the calculated correlation results from the database are interactively accessible on the web page and can be implemented for other related applications and researches. PMID:26881263

  3. General SIC measurement-based entanglement detection

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Li, Tao; Fei, Shao-Ming

    2015-06-01

    We study the quantum separability problem by using general symmetric informationally complete measurements and present separability criteria for both -dimensional bipartite and multipartite systems. The criterion for bipartite quantum states is effective in detecting several well-known classes of quantum states. For isotropic states, it becomes both necessary and sufficient. Furthermore, our criteria can be experimentally implemented, and the criterion for two-qudit states requires less local measurements than the one based on mutually unbiased measurements.

  4. Computational analysis of an autophagy/translation switch based on mutual inhibition of MTORC1 and ULK1

    DOE PAGESBeta

    Szymańska, Paulina; Martin, Katie R.; MacKeigan, Jeffrey P.; Hlavacek, William S.; Lipniacki, Tomasz

    2015-03-11

    We constructed a mechanistic, computational model for regulation of (macro)autophagy and protein synthesis (at the level of translation). The model was formulated to study the system-level consequences of interactions among the following proteins: two key components of MTOR complex 1 (MTORC1), namely the protein kinase MTOR (mechanistic target of rapamycin) and the scaffold protein RPTOR; the autophagy-initiating protein kinase ULK1; and the multimeric energy-sensing AMP-activated protein kinase (AMPK). Inputs of the model include intrinsic AMPK kinase activity, which is taken as an adjustable surrogate parameter for cellular energy level or AMP:ATP ratio, and rapamycin dose, which controls MTORC1 activity. Outputsmore » of the model include the phosphorylation level of the translational repressor EIF4EBP1, a substrate of MTORC1, and the phosphorylation level of AMBRA1 (activating molecule in BECN1-regulated autophagy), a substrate of ULK1 critical for autophagosome formation. The model incorporates reciprocal regulation of mTORC1 and ULK1 by AMPK, mutual inhibition of MTORC1 and ULK1, and ULK1-mediated negative feedback regulation of AMPK. Through analysis of the model, we find that these processes may be responsible, depending on conditions, for graded responses to stress inputs, for bistable switching between autophagy and protein synthesis, or relaxation oscillations, comprising alternating periods of autophagy and protein synthesis. A sensitivity analysis indicates that the prediction of oscillatory behavior is robust to changes of the parameter values of the model. The model provides testable predictions about the behavior of the AMPK-MTORC1-ULK1 network, which plays a central role in maintaining cellular energy and nutrient homeostasis.« less

  5. Computational analysis of an autophagy/translation switch based on mutual inhibition of MTORC1 and ULK1

    SciTech Connect

    Szymańska, Paulina; Martin, Katie R.; MacKeigan, Jeffrey P.; Hlavacek, William S.; Lipniacki, Tomasz

    2015-03-11

    We constructed a mechanistic, computational model for regulation of (macro)autophagy and protein synthesis (at the level of translation). The model was formulated to study the system-level consequences of interactions among the following proteins: two key components of MTOR complex 1 (MTORC1), namely the protein kinase MTOR (mechanistic target of rapamycin) and the scaffold protein RPTOR; the autophagy-initiating protein kinase ULK1; and the multimeric energy-sensing AMP-activated protein kinase (AMPK). Inputs of the model include intrinsic AMPK kinase activity, which is taken as an adjustable surrogate parameter for cellular energy level or AMP:ATP ratio, and rapamycin dose, which controls MTORC1 activity. Outputs of the model include the phosphorylation level of the translational repressor EIF4EBP1, a substrate of MTORC1, and the phosphorylation level of AMBRA1 (activating molecule in BECN1-regulated autophagy), a substrate of ULK1 critical for autophagosome formation. The model incorporates reciprocal regulation of mTORC1 and ULK1 by AMPK, mutual inhibition of MTORC1 and ULK1, and ULK1-mediated negative feedback regulation of AMPK. Through analysis of the model, we find that these processes may be responsible, depending on conditions, for graded responses to stress inputs, for bistable switching between autophagy and protein synthesis, or relaxation oscillations, comprising alternating periods of autophagy and protein synthesis. A sensitivity analysis indicates that the prediction of oscillatory behavior is robust to changes of the parameter values of the model. The model provides testable predictions about the behavior of the AMPK-MTORC1-ULK1 network, which plays a central role in maintaining cellular energy and nutrient homeostasis.

  6. Computational Analysis of an Autophagy/Translation Switch Based on Mutual Inhibition of MTORC1 and ULK1

    PubMed Central

    Szymańska, Paulina; Martin, Katie R.; MacKeigan, Jeffrey P.; Hlavacek, William S.; Lipniacki, Tomasz

    2015-01-01

    We constructed a mechanistic, computational model for regulation of (macro)autophagy and protein synthesis (at the level of translation). The model was formulated to study the system-level consequences of interactions among the following proteins: two key components of MTOR complex 1 (MTORC1), namely the protein kinase MTOR (mechanistic target of rapamycin) and the scaffold protein RPTOR; the autophagy-initiating protein kinase ULK1; and the multimeric energy-sensing AMP-activated protein kinase (AMPK). Inputs of the model include intrinsic AMPK kinase activity, which is taken as an adjustable surrogate parameter for cellular energy level or AMP:ATP ratio, and rapamycin dose, which controls MTORC1 activity. Outputs of the model include the phosphorylation level of the translational repressor EIF4EBP1, a substrate of MTORC1, and the phosphorylation level of AMBRA1 (activating molecule in BECN1-regulated autophagy), a substrate of ULK1 critical for autophagosome formation. The model incorporates reciprocal regulation of mTORC1 and ULK1 by AMPK, mutual inhibition of MTORC1 and ULK1, and ULK1-mediated negative feedback regulation of AMPK. Through analysis of the model, we find that these processes may be responsible, depending on conditions, for graded responses to stress inputs, for bistable switching between autophagy and protein synthesis, or relaxation oscillations, comprising alternating periods of autophagy and protein synthesis. A sensitivity analysis indicates that the prediction of oscillatory behavior is robust to changes of the parameter values of the model. The model provides testable predictions about the behavior of the AMPK-MTORC1-ULK1 network, which plays a central role in maintaining cellular energy and nutrient homeostasis. PMID:25761126

  7. Mutually Exclusive, Complementary, or . . .

    ERIC Educational Resources Information Center

    Schloemer, Cathy G.

    2016-01-01

    Whether students are beginning their study of probability or are well into it, distinctions between complementary sets and mutually exclusive sets can be confusing. Cathy Schloemer writes in this article that for years she used typical classroom examples but was not happy with the student engagement or the level of understanding they produced.…

  8. An approximately unbiased test of phylogenetic tree selection.

    PubMed

    Shimodaira, Hidetoshi

    2002-06-01

    An approximately unbiased (AU) test that uses a newly devised multiscale bootstrap technique was developed for general hypothesis testing of regions in an attempt to reduce test bias. It was applied to maximum-likelihood tree selection for obtaining the confidence set of trees. The AU test is based on the theory of Efron et al. (Proc. Natl. Acad. Sci. USA 93:13429-13434; 1996), but the new method provides higher-order accuracy yet simpler implementation. The AU test, like the Shimodaira-Hasegawa (SH) test, adjusts the selection bias overlooked in the standard use of the bootstrap probability and Kishino-Hasegawa tests. The selection bias comes from comparing many trees at the same time and often leads to overconfidence in the wrong trees. The SH test, though safe to use, may exhibit another type of bias such that it appears conservative. Here I show that the AU test is less biased than other methods in typical cases of tree selection. These points are illustrated in a simulation study as well as in the analysis of mammalian mitochondrial protein sequences. The theoretical argument provides a simple formula that covers the bootstrap probability test, the Kishino-Hasegawa test, the AU test, and the Zharkikh-Li test. A practical suggestion is provided as to which test should be used under particular circumstances. PMID:12079646

  9. Within-subject template estimation for unbiased longitudinal image analysis

    PubMed Central

    Reuter, Martin; Schmansky, Nicholas J.; Rosas, H. Diana; Fischl, Bruce

    2012-01-01

    Longitudinal image analysis has become increasingly important in clinical studies of normal aging and neurodegenerative disorders. Furthermore, there is a growing appreciation of the potential utility of longitudinally acquired structural images and reliable image processing to evaluate disease modifying therapies. Challenges have been related to the variability that is inherent in the available cross-sectional processing tools, to the introduction of bias in longitudinal processing and to potential over-regularization. In this paper we introduce a novel longitudinal image processing framework, based on unbiased, robust, within-subject template creation, for automatic surface reconstruction and segmentation of brain MRI of arbitrarily many time points. We demonstrate that it is essential to treat all input images exactly the same as removing only interpolation asymmetries is not sufficient to remove processing bias. We successfully reduce variability and avoid over-regularization by initializing the processing in each time point with common information from the subject template. The presented results show a significant increase in precision and discrimination power while preserving the ability to detect large anatomical deviations; as such they hold great potential in clinical applications, e.g. allowing for smaller sample sizes or shorter trials to establish disease specific biomarkers or to quantify drug effects. PMID:22430496

  10. An Unbiased Oncology Compound Screen to Identify Novel Combination Strategies.

    PubMed

    O'Neil, Jennifer; Benita, Yair; Feldman, Igor; Chenard, Melissa; Roberts, Brian; Liu, Yaping; Li, Jing; Kral, Astrid; Lejnine, Serguei; Loboda, Andrey; Arthur, William; Cristescu, Razvan; Haines, Brian B; Winter, Christopher; Zhang, Theresa; Bloecher, Andrew; Shumway, Stuart D

    2016-06-01

    Combination drug therapy is a widely used paradigm for managing numerous human malignancies. In cancer treatment, additive and/or synergistic drug combinations can convert weakly efficacious monotherapies into regimens that produce robust antitumor activity. This can be explained in part through pathway interdependencies that are critical for cancer cell proliferation and survival. However, identification of the various interdependencies is difficult due to the complex molecular circuitry that underlies tumor development and progression. Here, we present a high-throughput platform that allows for an unbiased identification of synergistic and efficacious drug combinations. In a screen of 22,737 experiments of 583 doublet combinations in 39 diverse cancer cell lines using a 4 by 4 dosing regimen, both well-known and novel synergistic and efficacious combinations were identified. Here, we present an example of one such novel combination, a Wee1 inhibitor (AZD1775) and an mTOR inhibitor (ridaforolimus), and demonstrate that the combination potently and synergistically inhibits cancer cell growth in vitro and in vivo This approach has identified novel combinations that would be difficult to reliably predict based purely on our current understanding of cancer cell biology. Mol Cancer Ther; 15(6); 1155-62. ©2016 AACR. PMID:26983881

  11. All-optical control of ultrafast photocurrents in unbiased graphene

    PubMed Central

    Obraztsov, Petr A.; Kaplas, Tommi; Garnov, Sergey V.; Kuwata-Gonokami, Makoto; Obraztsov, Alexander N.; Svirko, Yuri P.

    2014-01-01

    Graphene has recently become a unique playground for studying light-matter interaction effects in low-dimensional electronic systems. Being of strong fundamental importance, these effects also open a wide range of opportunities in photonics and optoelectronics. In particular, strong and broadband light absorption in graphene allows one to achieve high carrier densities essential for observation of nonlinear optical phenomena. Here, we make use of strong photon-drag effect to generate and optically manipulate ultrafast photocurrents in graphene at room temperature. In contrast to the recent reports on injection of photocurrents in graphene due to external or built-in electric field effects and by quantum interference, we force the massless charge carriers to move via direct transfer of linear momentum from photons of incident laser beam to excited electrons in unbiased sample. Direction and amplitude of the drag-current induced in graphene are determined by polarization, incidence angle and intensity of the obliquely incident laser beam. We also demonstrate that the irradiation of graphene with two laser beams of the same wavelength offers an opportunity to manipulate the photocurrents in time domain. The obtained all-optical control of the photocurrents opens new routes towards graphene based high-speed and broadband optoelectronic devices. PMID:24500084

  12. Unbiased methods for removing systematics from galaxy clustering measurements

    NASA Astrophysics Data System (ADS)

    Elsner, Franz; Leistedt, Boris; Peiris, Hiranya V.

    2016-02-01

    Measuring the angular clustering of galaxies as a function of redshift is a powerful method for extracting information from the three-dimensional galaxy distribution. The precision of such measurements will dramatically increase with ongoing and future wide-field galaxy surveys. However, these are also increasingly sensitive to observational and astrophysical contaminants. Here, we study the statistical properties of three methods proposed for controlling such systematics - template subtraction, basic mode projection, and extended mode projection - all of which make use of externally supplied template maps, designed to characterize and capture the spatial variations of potential systematic effects. Based on a detailed mathematical analysis, and in agreement with simulations, we find that the template subtraction method in its original formulation returns biased estimates of the galaxy angular clustering. We derive closed-form expressions that should be used to correct results for this shortcoming. Turning to the basic mode projection algorithm, we prove it to be free of any bias, whereas we conclude that results computed with extended mode projection are biased. Within a simplified setup, we derive analytical expressions for the bias and discuss the options for correcting it in more realistic configurations. Common to all three methods is an increased estimator variance induced by the cleaning process, albeit at different levels. These results enable unbiased high-precision clustering measurements in the presence of spatially varying systematics, an essential step towards realizing the full potential of current and planned galaxy surveys.

  13. Unbiased diffusion of Brownian particles on disordered correlated potentials

    NASA Astrophysics Data System (ADS)

    Salgado-Garcia, Raúl; Maldonado, Cesar

    2015-06-01

    In this work we study the diffusion of non-interacting overdamped particles, moving on unbiased disordered correlated potentials, subjected to Gaussian white noise. We obtain an exact expression for the diffusion coefficient which allows us to prove that the unbiased diffusion of overdamped particles on a random polymer does not depend on the correlations of the disordered potentials. This universal behavior of the unbiased diffusivity is a direct consequence of the validity of the Einstein relation and the decay of correlations of the random polymer. We test the independence on correlations of the diffusion coefficient for correlated polymers produced by two different stochastic processes, a one-step Markov chain and the expansion-modification system. Within the accuracy of our simulations, we found that the numerically obtained diffusion coefficient for these systems agree with the analytically calculated ones, confirming our predictions.

  14. Estimating unbiased phenological trends by adapting site-occupancy models.

    PubMed

    Roth, Tobias; Strebel, Nicolas; Amrhein, Valentin

    2014-08-01

    As a response to climate warming, many animals and plants have been found to shift phenologies, such as appearance in spring or timing of reproduction. However, traditional measures for shifts in phenology that are based on observational data likely are biased due to a large influence of population size, observational effort, starting date of a survey, or other causes that may affect the probability of detecting a species. Understanding phenological responses of species to climate change, however, requires a robust measure that could be compared among studies and study years. Here, we developed a new method for estimating arrival and departure dates based on site-occupancy models. Using simulated data, we show that our method provided virtually unbiased estimates of phenological events even if detection probability or the number of sites occupied by the species is changing over time. To illustrate the flexibility of our method, we analyzed spring arrival of two long-distance migrant songbirds and the length of the flight period of two butterfly species, using data from a long-term biodiversity monitoring program in Switzerland. In contrast to many birds that migrate short distances, the two long-distance migrant songbirds tended to postpone average spring arrival by -0.5 days per year between 1995 and 2012. Furthermore, the flight period of the short-distance-flying butterfly species apparently became even shorter over the study period, while the flight period of the longer-distance-flying butterfly species remained relatively stable. Our method could be applied to temporally and spatially extensive data from a wide range of monitoring programs and citizen science projects, to help unravel how species and communities respond to global warming. PMID:25230466

  15. Extending unbiased stereology of brain ultrastructure to three-dimensional volumes

    NASA Technical Reports Server (NTRS)

    Fiala, J. C.; Harris, K. M.; Koslow, S. H. (Principal Investigator)

    2001-01-01

    OBJECTIVE: Analysis of brain ultrastructure is needed to reveal how neurons communicate with one another via synapses and how disease processes alter this communication. In the past, such analyses have usually been based on single or paired sections obtained by electron microscopy. Reconstruction from multiple serial sections provides a much needed, richer representation of the three-dimensional organization of the brain. This paper introduces a new reconstruction system and new methods for analyzing in three dimensions the location and ultrastructure of neuronal components, such as synapses, which are distributed non-randomly throughout the brain. DESIGN AND MEASUREMENTS: Volumes are reconstructed by defining transformations that align the entire area of adjacent sections. Whole-field alignment requires rotation, translation, skew, scaling, and second-order nonlinear deformations. Such transformations are implemented by a linear combination of bivariate polynomials. Computer software for generating transformations based on user input is described. Stereological techniques for assessing structural distributions in reconstructed volumes are the unbiased bricking, disector, unbiased ratio, and per-length counting techniques. A new general method, the fractional counter, is also described. This unbiased technique relies on the counting of fractions of objects contained in a test volume. A volume of brain tissue from stratum radiatum of hippocampal area CA1 is reconstructed and analyzed for synaptic density to demonstrate and compare the techniques. RESULTS AND CONCLUSIONS: Reconstruction makes practicable volume-oriented analysis of ultrastructure using such techniques as the unbiased bricking and fractional counter methods. These analysis methods are less sensitive to the section-to-section variations in counts and section thickness, factors that contribute to the inaccuracy of other stereological methods. In addition, volume reconstruction facilitates visualization

  16. Extending Unbiased Stereology of Brain Ultrastructure to Three-dimensional Volumes

    PubMed Central

    Fiala, John C.; Harris, Kristen M.

    2001-01-01

    Objective: Analysis of brain ultrastructure is needed to reveal how neurons communicate with one another via synapses and how disease processes alter this communication. In the past, such analyses have usually been based on single or paired sections obtained by electron microscopy. Reconstruction from multiple serial sections provides a much needed, richer representation of the three-dimensional organization of the brain. This paper introduces a new reconstruction system and new methods for analyzing in three dimensions the location and ultrastructure of neuronal components, such as synapses, which are distributed non-randomly throughout the brain. Design and Measurements: Volumes are reconstructed by defining transformations that align the entire area of adjacent sections. Whole-field alignment requires rotation, translation, skew, scaling, and second-order nonlinear deformations. Such transformations are implemented by a linear combination of bivariate polynomials. Computer software for generating transformations based on user input is described. Stereological techniques for assessing structural distributions in reconstructed volumes are the unbiased bricking, disector, unbiased ratio, and per-length counting techniques. A new general method, the fractional counter, is also described. This unbiased technique relies on the counting of fractions of objects contained in a test volume. A volume of brain tissue from stratum radiatum of hippocampal area CA1 is reconstructed and analyzed for synaptic density to demonstrate and compare the techniques. Results and Conclusion: Reconstruction makes practicable volume-oriented analysis of ultrastructure using such techniques as the unbiased bricking and fractional counter methods. These analysis methods are less sensitive to the section-to-section variations in counts and section thickness, factors that contribute to the inaccuracy of other stereological methods. In addition, volume reconstruction facilitates visualization

  17. Unbiased Estimates of Variance Components with Bootstrap Procedures

    ERIC Educational Resources Information Center

    Brennan, Robert L.

    2007-01-01

    This article provides general procedures for obtaining unbiased estimates of variance components for any random-model balanced design under any bootstrap sampling plan, with the focus on designs of the type typically used in generalizability theory. The results reported here are particularly helpful when the bootstrap is used to estimate standard…

  18. Research on the relationships of the domestic mutual investment of China based on the cross-shareholding networks of the listed companies

    NASA Astrophysics Data System (ADS)

    Ma, Yuan-yuan; Zhuang, Xin-tian; Li, Ling-xuan

    2011-02-01

    Enterprises are the core power and the carriers to promote the country's economy developing sustainably and rapidly; the listed enterprises are the outstanding companies which can represent the economic level at the places where the enterprises are located, so we establish the cross-shareholding networks of the listed companies between 2002 and 2009, and then analyze the mutual investment at company-level, province-level and region-level. We have researched the overall trend of economic development and the overall tendency of capital flow of China in the recent 8 years based on the cross-shareholding networks, the influence of a global economic crisis on the stock markets and the overall economics of China in 2008 and the recovery of the economy after the economic crisis. Moreover, we analyze the variations of the cross-shareholding networks and the influence of the state-owned large and medium enterprises listing frequently on Chinese stock markets. We divide the provinces of China into 3 main categories according to their industrial situations. Though the analysis, we find that the wealth gap between the different areas is not significantly reduced even though the government has carried out strategies such as the Development of the West Regions and the Rejuvenation of Old Industrial Bases in Northeastern China. We analyze the cumulative distribution function of the degree of the vertices and use large amounts of data to do empirical analysis. The methods used include the hierarchical cluster analysis, regression analysis, etc.

  19. Mutual synchronization of nanoconstriction-based spin Hall nano-oscillators through evanescent and propagating spin waves

    NASA Astrophysics Data System (ADS)

    Kendziorczyk, T.; Kuhn, T.

    2016-04-01

    We perform a micromagnetic study of the synchronization dynamics in nanoconstriction-based spin Hall nano-oscillator (SHNO) arrays. The simulation reveals that efficient synchronization in this kind of system is possible, and indicates that the synchronization is mediated by a combination of linear coupling through the overlap of localized modes and parametric coupling through propagating spin waves which are excited by the second harmonic oscillation in the SHNOs. Due to the anisotropic spin wave dispersion in the studied system, the synchronization properties decisively depend on the geometrical alignment of the SHNO array with respect to the external field. We find that, by utilizing the directional spin wave emission and correspondingly optimizing the alignment of the SHNO array, the synchronization is enhanced with a significant increase of the phase-locking bandwidth.

  20. Rhodamine based dual probes for selective detection of mercury and fluoride ions in water using two mutually independent sensing pathways.

    PubMed

    Kumari, Namita; Dey, Nilanjan; Bhattacharya, Santanu

    2014-05-21

    New rhodamine based molecules have been designed as dual probes for the ppb-level selective detection of Hg(2+) and F(-) ions in aqueous medium at physiological pH 7.4. The probes have been designed in such a way to utilize both the properties of the metal ion induced 'turn-on' detection mechanism of the spirolactam ring opening of the rhodamine moiety and the reaction based cleavage of the O-silyl bond in presence of the fluoride ion. The probes have been synthesized conveniently by coupling rhodamine hydrazone with O-silyl protected mono- and di-hydroxybenzaldehydes. Both the probes showed a 'turn-on' detection of the fluoride ion due to the cleavage of the O-silyl bond upon treatment with the added F(-) ion. However, the probes showed selective 'turn-on' detection of Hg(2+) ion by opening of the spirolactam ring. The two detection mechanisms worked in isolation and hence the corresponding spectral responses appeared completely independent of each other. The presence of Hg(2+) in solution induced generation of an intense pink color with bright green fluorescence emission. In contrast a deep yellow color with yellow fluorescence was observed upon addition of the fluoride ion to the probe solution. Two different mechanisms of interactions have been proposed on the basis of (1)H-NMR, IR and mass spectrometric studies. Thus, using a single probe the selective sensing of two different ions could be achieved in aqueous medium well below their permitted limit of detection. PMID:24669370

  1. Unbiased rigid registration using transfer functions

    NASA Astrophysics Data System (ADS)

    Hahn, Dieter A.; Hornegger, Joachim; Bautz, Werner; Kuwert, Torsten; Roemer, Wolfgang

    2005-04-01

    The evaluation of tumor growth as regression under therapy is an important clinical issue. Rigid registration of sequentially acquired 3D-images has proven its value for this purpose. Existing approaches to rigid image registration use the whole volume for the estimation of the rigid transform. Non-rigid soft tissue deformation, however, will imply a bias to the registration result, because local deformations cannot be modeled by rigid transforms. Anatomical substructures, like bones or teeth, are not affected by these deformations, but follow a rigid transform. This important observation is incorporated in the proposed registration algorithm. The selection of anatomical substructure is done by manual interaction of medical experts adjusting the transfer function of the volume rendering software. The parameters of the transfer function are used to identify the voxels that are considered for registration. A rigid transform is estimated by a quaternion gradient descent algorithm based on the intensity values of the specified tissue classes. Commonly used voxel intensity measures are adjusted to the modified registration algorithm. The contribution describes the mathematical framework of the proposed registration method and its implementation in a commercial software package. The experimental evaluation includes the discussion of different similarity measures, the comparison of the proposed method to established rigid registration techniques and the evaluation of the efficiency of the new method. We conclude with the discussion of potential medical applications of the proposed registration algorithm.

  2. The effect of turbulence on entanglement-based free-space quantum key distribution with photonic orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Goyal, Sandeep K.; Hamadou Ibrahim, Alpha; Roux, Filippus S.; Konrad, Thomas; Forbes, Andrew

    2016-06-01

    Using an experimental setup that simulates a turbulent atmosphere, we study the secret key rate for quantum key distribution (QKD) protocols in orbital angular momentum based free space quantum communication. The QKD protocols under consideration include the Ekert 91 protocol for different choices of mutually unbiased bases and the six-state protocol. We find that the secret key rate of these protocols decay to zero, roughly at the same scale where the entanglement of formation decays to zero.

  3. Unbiased quantitative testing of conventional orthodontic beliefs.

    PubMed

    Baumrind, S

    1998-03-01

    This study used a preexisting database to test in hypothesis from the appropriateness of some common orthodontic beliefs concerning upper first molar displacement and changes in facial morphology associated with conventional full bonded/banded treatment in growing subjects. In an initial pass, the author used data from a stratified random sample of 48 subjects drawn retrospectively from the practice of a single, experienced orthodontist. This sample consisted of 4 subgroups of 12 subjects each: Class I nonextraction, Class I extraction, Class II nonextraction, and Class II extraction. The findings indicate that, relative to the facial profile, chin point did not, on average, displace anteriorly during treatment, either overall or in any subgroup. Relative to the facial profile, Point A became significantly less prominent during treatment, both overall and in each subgroup. The best estimate of the mean displacement of the upper molar cusp relative to superimposition on Anterior Cranial Base was in the mesial direction in each of the four subgroups. In only one extraction subject out of 24 did the cusp appear to be displaced distally. Mesial molar cusp displacement was significantly greater in the Class II extraction subgroup than in the Class II nonextraction subgroup. Relative to superimposition on anatomical "best fit" of maxillary structures, the findings for molar cusp displacement were similar, but even more dramatic. Mean mesial migration was highly significant in both the Class II nonextraction and Class II extraction subgroups. In no subject in the entire sample was distal displacement noted relative to this superimposition. Mean increase in anterior Total Face Height was significantly greater in the Class II extraction subgroup than in the Class II nonextraction subgroup. (This finding was contrary to the author's original expectation.) The generalizability of the findings from the initial pass to other treated growing subjects was then assessed by

  4. Mutual information and spontaneous symmetry breaking

    NASA Astrophysics Data System (ADS)

    Hamma, A.; Giampaolo, S. M.; Illuminati, F.

    2016-01-01

    We show that the metastable, symmetry-breaking ground states of quantum many-body Hamiltonians have vanishing quantum mutual information between macroscopically separated regions and are thus the most classical ones among all possible quantum ground states. This statement is obvious only when the symmetry-breaking ground states are simple product states, e.g., at the factorization point. On the other hand, symmetry-breaking states are in general entangled along the entire ordered phase, and to show that they actually feature the least macroscopic correlations compared to their symmetric superpositions is highly nontrivial. We prove this result in general, by considering the quantum mutual information based on the two-Rényi entanglement entropy and using a locality result stemming from quasiadiabatic continuation. Moreover, in the paradigmatic case of the exactly solvable one-dimensional quantum X Y model, we further verify the general result by considering also the quantum mutual information based on the von Neumann entanglement entropy.

  5. Classification of brain signals associated with imagination of hand grasping, opening and reaching by means of wavelet-based common spatial pattern and mutual information.

    PubMed

    Amanpour, Behzad; Erfanian, Abbas

    2013-01-01

    An important issue in designing a practical brain-computer interface (BCI) is the selection of mental tasks to be imagined. Different types of mental tasks have been used in BCI including left, right, foot, and tongue motor imageries. However, the mental tasks are different from the actions to be controlled by the BCI. It is desirable to select a mental task to be consistent with the desired action to be performed by BCI. In this paper, we investigated the detecting the imagination of the hand grasping, hand opening, and hand reaching in one hand using electroencephalographic (EEG) signals. The results show that the ERD/ERS patterns, associated with the imagination of hand grasping, opening, and reaching are different. For classification of brain signals associated with these mental tasks and feature extraction, a method based on wavelet packet, regularized common spatial pattern (CSP), and mutual information is proposed. The results of an offline analysis on five subjects show that the two-class mental tasks can be classified with an average accuracy of 77.6% using proposed method. In addition, we examine the proposed method on datasets IVa from BCI Competition III and IIa from BCI Competition IV. PMID:24110165

  6. Reconstructing palaeotemperatures for the Early and Middle Pleistocene using the mutual climatic range method based on plant fossils

    NASA Astrophysics Data System (ADS)

    Pross, Jörg; Klotz, Stefan; Mosbrugger, Volker

    2000-12-01

    A new approach is proposed to obtain quantitative temperature reconstructions from Early and Middle Pleistocene pollen and megafloral records. Utilizing the indicator species concept pioneered by Iversen (1944, Geologiska Föreningen Förhandlingar Stockholm 66, 463-483), the new methodology overcomes the problem of non-analogue plant communities by only taking into account the presence/absence of taxa rather than their relative abundances. Based on the present day thermal tolerances of the taxa from a fossil assemblage, the temperature interval in which all taxa from this assemblage can coexist is determined. A databank containing the climate tolerances of 85 taxa from European pollen records was established. To increase the temperature resolution of the method, procedures were developed to assess the most likely intervals for the actual temperatures within the calculated common thermospheres and the routine evaluation of the mean temperatures of the warmest and coldest months (MTW and MTC). After calibrating the approach on modern assemblages, it was applied to Tiglian and Holsteinian pollen sequences from Lieth (northern Germany) and Lac du Bourget (northern French Alps). For both records the method yields detailed temperature reconstructions of temperate and cold episodes. During the coldest episode of the Lieth section, the MTC may have been as low as -16°C. Corresponding MTW values range from 14.5 to 21°C, thus testifying to a strong continentality at that time. During the warmest period reconstructed for the Lieth section, the MTC was similar to the value as measured in the area today (1.5°C), whereas the MTW was probably higher than at present (20.1°C). For the coldest interval from the Lac du Bourget pollen sequence, the reconstructed MTC values reach a minimum of -15°C. Corresponding MTW values range from 15 to 22°C, again implying a strong continentality. For the warmest period our approach yields MTC values between -2 and 2°C and MTW values

  7. Mutual information rate and bounds for it.

    PubMed

    Baptista, Murilo S; Rubinger, Rero M; Viana, Emilson R; Sartorelli, José C; Parlitz, Ulrich; Grebogi, Celso

    2012-01-01

    The amount of information exchanged per unit of time between two nodes in a dynamical network or between two data sets is a powerful concept for analysing complex systems. This quantity, known as the mutual information rate (MIR), is calculated from the mutual information, which is rigorously defined only for random systems. Moreover, the definition of mutual information is based on probabilities of significant events. This work offers a simple alternative way to calculate the MIR in dynamical (deterministic) networks or between two time series (not fully deterministic), and to calculate its upper and lower bounds without having to calculate probabilities, but rather in terms of well known and well defined quantities in dynamical systems. As possible applications of our bounds, we study the relationship between synchronisation and the exchange of information in a system of two coupled maps and in experimental networks of coupled oscillators. PMID:23112809

  8. Mutually temporally independent connectivity patterns: a new framework to study the dynamics of brain connectivity at rest with application to explain group difference based on gender.

    PubMed

    Yaesoubi, Maziar; Miller, Robyn L; Calhoun, Vince D

    2015-02-15

    Functional connectivity analysis of the human brain is an active area in fMRI research. It focuses on identifying meaningful brain networks that have coherent activity either during a task or in the resting state. These networks are generally identified either as collections of voxels whose time series correlate strongly with a pre-selected region or voxel, or using data-driven methodologies such as independent component analysis (ICA) that compute sets of maximally spatially independent voxel weightings (component spatial maps (SMs)), each associated with a single time course (TC). Studies have shown that regardless of the way these networks are defined, the activity coherence among them has a dynamic nature which is hard to estimate with global coherence analysis such as correlation or mutual information. Sliding window analyses in which functional network connectivity (FNC) is estimated separately at each time window is one of the more widely employed approaches to studying the dynamic nature of functional network connectivity (dFNC). Observed FNC patterns are summarized and replaced with a smaller set of prototype connectivity patterns ("states" or "components"), and then a dynamical analysis is applied to the resulting sequences of prototype states. In this work we are looking for a small set of connectivity patterns whose weighted contributions to the dynamically changing dFNCs are independent of each other in time. We discuss our motivation for this work and how it differs from existing approaches. Also, in a group analysis based on gender we show that males significantly differ from females by occupying significantly more combinations of these connectivity patterns over the course of the scan. PMID:25485713

  9. Child Temperament Moderates Effects of Parent-Child Mutuality on Self-Regulation: A Relationship-Based Path for Emotionally Negative Infants

    ERIC Educational Resources Information Center

    Kim, Sanghag; Kochanska, Grazyna

    2012-01-01

    This study examined infants' negative emotionality as moderating the effect of parent-child mutually responsive orientation (MRO) on children's self-regulation (n = 102). Negative emotionality was observed in anger-eliciting episodes and in interactions with parents at 7 months. MRO was coded in naturalistic interactions at 15 months.…

  10. The Evolution of Interspecific Mutualisms

    NASA Astrophysics Data System (ADS)

    Doebeli, Michael; Knowlton, Nancy

    1998-07-01

    Interspecific mutualisms are widespread, but how they evolve is not clear. The Iterated Prisoner's Dilemma is the main theoretical tool to study cooperation, but this model ignores ecological differences between partners and assumes that amounts exchanged cannot themselves evolve. A more realistic model incorporating these features shows that strategies that succeed with fixed exchanges (e.g., Tit-for-Tat) cannot explain mutualism when exchanges vary because the amount exchanged evolves to 0. For mutualism to evolve, increased investments in a partner must yield increased returns, and spatial structure in competitive interactions is required. Under these biologically plausible assumptions, mutualism evolves with surprising ease. This suggests that, contrary to the basic premise of past theoretical analyses, overcoming a potential host's initial defenses may be a bigger obstacle for mutualism than the subsequent recurrence and spread of noncooperative mutants.

  11. [Human cerebral image registration using generalized mutual information].

    PubMed

    Zhang, Jingzhou; Li, Ting; Zhang, Jia

    2008-12-01

    Medical image registration is a highlight of actual research on medical image processing. Based onsimilarity measure of Shannon entropy, a new generalized distance measurement based on Rényi entropy applied to image rigid registration is introduced and is called here generalized mutual information (GMI). It is used in three dimensional cerebral image registration experiments. The simulation results show that generalized distance measurement and Shannon entropy measurement apply to different areas; that the registration measure based o n generalized distance is a natural extension of mutual information of Shannon entropy. The results prove that generalized mutual information uses less time than simple mutual information does, and the new similarity measure manifests higher degree of consistency between the two cerebral registration images. Also, the registration results provide the clinical diagnoses with more important references. In conclusion, generalized mutual information has satisfied the demands of clinical application to a wide extent. PMID:19166197

  12. [Biological mutualism, concepts and models].

    PubMed

    Perru, Olivier

    2011-01-01

    Mutualism is a biological association for a mutual benefit between two different species. In this paper, firstly, we examine the history and signification of mutualism in relation to symbiosis. Then, we consider the link between concepts and models of mutualism. Models of mutualism depend on different concepts we use: If mutualism is situated at populations' level, it will be expressed by Lotka-Volterra models, concerning exclusively populations' size. If mutualism is considered as a resources' exchange or a biological market increasing the fitness of these organisms, it will be described at an individual level by a cost-benefit model. Our analysis will be limited to the history and epistemology of Lotka-Volterra models and we hypothesize that these models are adapted at first to translate dynamic evolutions of mutualism. They render stability or variations of size and assume that there are clear distinctions and a state of equilibrium between populations of different species. Italian mathematician Vito Volterra demonstrated that biological associations consist in a constant relation between some species. In 1931 and 1935, Volterra described the general form of antagonistic or mutualistic biological associations by the same differential equations. We recognize that these equations have been more used to model competition or prey-predator interactions, but a simple sign change allows describing mutualism. The epistemological problem is the following: Volterra's equations help us to conceptualize a global phenomenon. However, mutualistic interactions may have stronger effects away from equilibrium and these effects may be better understood at individual level. We conclude that, between 1985 and 2000, some researchers carried on working and converting Lotka-Volterra models but this description appeared as insufficient. So, other researchers adopted an economical viewpoint, considering mutualism as a biological market. PMID:22288336

  13. Unbiased estimation of mutation rates under fluctuating final counts.

    PubMed

    Ycart, Bernard; Veziris, Nicolas

    2014-01-01

    Estimation methods for mutation rates (or probabilities) in Luria-Delbrück fluctuation analysis usually assume that the final number of cells remains constant from one culture to another. We show that this leads to systematically underestimate the mutation rate. Two levels of information on final numbers are considered: either the coefficient of variation has been independently estimated, or the final number of cells in each culture is known. In both cases, unbiased estimation methods are proposed. Their statistical properties are assessed both theoretically and through Monte-Carlo simulation. As an application, the data from two well known fluctuation analysis studies on Mycobacterium tuberculosis are reexamined. PMID:24988217

  14. Mobility of Holstein Polaron at Finite Temperature: An Unbiased Approach

    NASA Astrophysics Data System (ADS)

    Mishchenko, A. S.; Nagaosa, N.; De Filippis, G.; de Candia, A.; Cataudella, V.

    2015-04-01

    We present the first unbiased results for the mobility μ of a one-dimensional Holstein polaron obtained by numerical analytic continuation combined with diagrammatic and worldline Monte Carlo methods in the thermodynamic limit. We have identified for the first time several distinct regimes in the λ -T plane including a band conduction region, incoherent metallic region, an activated hopping region, and a high-temperature saturation region. We observe that although mobilities and mean free paths at different values of λ differ by many orders of magnitude at small temperatures, their values at T larger than the bandwidth become very close to each other.

  15. Grief and Palliative Care: Mutuality

    PubMed Central

    Moon, Paul J

    2013-01-01

    Grief and palliative care are interrelated and perhaps mutually inclusive. Conceptually and practically, grief intimately relates to palliative care, as both domains regard the phenomena of loss, suffering, and a desire for abatement of pain burden. Moreover, the notions of palliative care and grief may be construed as being mutually inclusive in terms of one cueing the other. As such, the discussions in this article will center on the conceptualizations of the mutuality between grief and palliative care related to end-of-life circumstances. Specifically, the complementarity of grief and palliative care, as well as a controvertible view thereof, will be considered. PMID:25278758

  16. Far-infrared observations of an unbiased sample of gamma-ray burst host galaxies

    NASA Astrophysics Data System (ADS)

    Kohn, S. A.; Michałowski, M. J.; Bourne, N.; Baes, M.; Fritz, J.; Cooray, A.; De Looze, I.; De Zotti, G.; Dannerbauer, H.; Dunne, L.; Dye, S.; Eales, S.; Furlanetto, C.; Gonzalez-Nuevo, J.; Ibar, E.; Ivison, R. J.; Maddox, S. J.; Scott, D.; Smith, D. J. B.; Smith, M. W. L.; Symeonidis, M.; Valiante, E.

    2015-04-01

    Gamma-ray bursts (GRBs) are the most energetic phenomena in the Universe; believed to result from the collapse and subsequent explosion of massive stars. Even though it has profound consequences for our understanding of their nature and selection biases, little is known about the dust properties of the galaxies hosting GRBs. We present analysis of the far-infrared properties of an unbiased sample of 20 BeppoSAX and Swift GRB host galaxies (at an average redshift of z = 3.1) located in the Herschel Astrophysical Terahertz Large Area Survey, the Herschel Virgo Cluster Survey, the Herschel Fornax Cluster Survey, the Herschel Stripe 82 Survey and the Herschel Multi-tiered Extragalactic Survey, totalling 880 deg2, or ˜3 per cent of the sky in total. Our sample selection is serendipitous, based only on whether the X-ray position of a GRB lies within a large-scale Herschel survey - therefore our sample can be considered completely unbiased. Using deep data at wavelengths of 100-500 μm, we tentatively detected 1 out of 20 GRB hosts located in these fields. We constrain their dust masses and star formation rates (SFRs), and discuss these in the context of recent measurements of submillimetre galaxies and ultraluminous infrared galaxies. The average far-infrared flux of our sample gives an upper limit on SFR of <114 M⊙ yr-1. The detection rate of GRB hosts is consistent with that predicted assuming that GRBs trace the cosmic SFR density in an unbiased way, i.e. that the fraction of GRB hosts with SFR > 500 M⊙ yr-1 is consistent with the contribution of such luminous galaxies to the cosmic star formation density.

  17. Improving Agricultural Drought Monitoring in East Africa with Unbiased Rainfall Fields and Detailed Land Surface Physics

    NASA Astrophysics Data System (ADS)

    McNally, A.; Yatheendradas, S.; Peters-Lidard, C. D.; Michaelsen, J.

    2010-12-01

    Monitoring drought is particularly challenging within rainfed agricultural and pastoral systems, where it can serve the greatest need. Such locations often have sparse or non-existent ground based measurements of precipitation, evapotranspiration (ET), and soil moisture. For more effective drought monitoring with limited hydroclimate observations, we simulate land surface states using the Community Noah Land Surface Model forced with different merged rainfall products inside a Land Information System (LIS). Using model outputs we will answer the questions: How sensitive are soil moisture and ET fields to differences in rainfall forcing and model physics? What are acceptable drought-specific tradeoffs between near-real time availability and skill of rainfall data? Preliminary results with the African Rainfall Estimation Algorithm Version 2 (RFE2.0) outperformed global products, suggesting that sub-global rainfall estimates are the way forward for regional drought monitoring. Specifically, the Noah model forced with RFE2.0 better resolved the heterogeneous patterns in crop stress than the Famine Early Warning System Network (FEWS NET) operational Water Requirement Satisfaction Index (WRSI) model. To further investigate the improvement in drought monitoring while maintaining timeliness, we unbias (using Africa specific climatology) the precipitation products from CPC Merged Analysis of Precipitation (CMAP), Tropical Rainfall Measurement Mission (TRMM), and RFE2.0. The skill (relative accuracy) and reliability (average agreement) of the unbiased rainfall are calculated against an unbiased precipitation product augmented with station data from Ethiopia and Kenya. Soil moisture and ET fields from Noah are compared to the operational FEWS NET WRSI, soil water anomaly index, and the World Food Program’s Crop and Food Security Assessment Mission reports. We anticipate that the unbiased rainfall fields will improve the accuracy, spatio-temporal resolution, and

  18. Two Mutually Exclusive Local Chromatin States Drive Efficient V(D)J Recombination.

    PubMed

    Bolland, Daniel J; Koohy, Hashem; Wood, Andrew L; Matheson, Louise S; Krueger, Felix; Stubbington, Michael J T; Baizan-Edge, Amanda; Chovanec, Peter; Stubbs, Bryony A; Tabbada, Kristina; Andrews, Simon R; Spivakov, Mikhail; Corcoran, Anne E

    2016-06-14

    Variable (V), diversity (D), and joining (J) (V(D)J) recombination is the first determinant of antigen receptor diversity. Understanding how recombination is regulated requires a comprehensive, unbiased readout of V gene usage. We have developed VDJ sequencing (VDJ-seq), a DNA-based next-generation-sequencing technique that quantitatively profiles recombination products. We reveal a 200-fold range of recombination efficiency among recombining V genes in the primary mouse Igh repertoire. We used machine learning to integrate these data with local chromatin profiles to identify combinatorial patterns of epigenetic features that associate with active VH gene recombination. These features localize downstream of VH genes and are excised by recombination, revealing a class of cis-regulatory element that governs recombination, distinct from expression. We detect two mutually exclusive chromatin signatures at these elements, characterized by CTCF/RAD21 and PAX5/IRF4, which segregate with the evolutionary history of associated VH genes. Thus, local chromatin signatures downstream of VH genes provide an essential layer of regulation that determines recombination efficiency. PMID:27264181

  19. Toward automated quantification of biological microstructures using unbiased stereology

    NASA Astrophysics Data System (ADS)

    Bonam, Om P.; Elozory, Daniel; Kramer, Kurt; Goldgof, Dmitry; Hall, Lawrence O.; Mangual, Osvaldo; Mouton, Peter R.

    2011-03-01

    Quantitative analysis of biological microstructures using unbiased stereology plays a large and growing role in bioscience research. Our aim is to add a fully automatic, high-throughput mode to a commercially available, computerized stereology device (Stereologer). The current method for estimation of first- and second order parameters of biological microstructures, requires a trained user to manually select objects of interest (cells, fibers etc.,) while stepping through the depth of a stained tissue section in fixed intervals. The proposed approach uses a combination of color and gray-level processing. Color processing is used to identify the objects of interest, by training on the images to obtain the threshold range for objects of interest. In gray-level processing, a region-growing approach was used to assign a unique identity to the objects of interest and enumerate them. This automatic approach achieved an overall object detection rate of 93.27%. Thus, these results support the view that automatic color and gray-level processing combined with unbiased sampling and assumption and model-free geometric probes can provide accurate and efficient quantification of biological objects.

  20. Reveal quantum correlation in complementary bases

    PubMed Central

    Wu, Shengjun; Ma, Zhihao; Chen, Zhihua; Yu, Sixia

    2014-01-01

    An essential feature of genuine quantum correlation is the simultaneous existence of correlation in complementary bases. We reveal this feature of quantum correlation by defining measures based on invariance under a basis change. For a bipartite quantum state, the classical correlation is the maximal correlation present in a certain optimum basis, while the quantum correlation is characterized as a series of residual correlations in the mutually unbiased bases. Compared with other approaches to quantify quantum correlation, our approach gives information-theoretical measures that directly reflect the essential feature of quantum correlation. PMID:24503595

  1. Construction of an Unbiased Spatio-temporal Atlas of the Tongue During Speech

    PubMed Central

    Woo, Jonghye; Xing, Fangxu; Lee, Junghoon; Stone, Maureen; Prince, Jerry L.

    2016-01-01

    Quantitative characterization and comparison of tongue motion during speech and swallowing present fundamental challenges because of striking variations in tongue structure and motion across subjects. A reliable and objective description of the dynamics tongue motion requires the consistent integration of inter-subject variability to detect the subtle changes in populations. To this end, in this work, we present an approach to constructing an unbiased spatio-temporal atlas of the tongue during speech for the first time, based on cine-MRI from twenty two normal subjects. First, we create a common spatial space using images from the reference time frame, a neutral position, in which the unbiased spatio-temporal atlas can be created. Second, we transport images from all time frames of all subjects into this common space via the single transformation. Third, we construct atlases for each time frame via groupwise diffeomorphic registration, which serves as the initial spatio-temporal atlas. Fourth, we update the spatio-temporal atlas by realigning each time sequence based on the Lipschitz norm on diffeomorphisms between each subject and the initial atlas. We evaluate and compare different configurations such as similarity measures to build the atlas. Our proposed method permits to accurately and objectively explain the main pattern of tongue surface motion. PMID:26221715

  2. Unbiased water and methanol maser surveys of NGC 1333

    SciTech Connect

    Lyo, A-Ran; Kim, Jongsoo; Byun, Do-Young; Lee, Ho-Gyu

    2014-11-01

    We present the results of unbiased 22 GHz H{sub 2}O water and 44 GHz class I CH{sub 3}OH methanol maser surveys in the central 7' × 10' area of NGC 1333 and two additional mapping observations of a 22 GHz water maser in a ∼3' × 3' area of the IRAS4A region. In the 22 GHz water maser survey of NGC 1333 with a sensitivity of σ ∼ 0.3 Jy, we confirmed the detection of masers toward H{sub 2}O(B) in the region of HH 7-11 and IRAS4B. We also detected new water masers located ∼20'' away in the western direction of IRAS4B or ∼25'' away in the southern direction of IRAS4A. We could not, however, find young stellar objects or molecular outflows associated with them. They showed two different velocity components of ∼0 and ∼16 km s{sup –1}, which are blue- and redshifted relative to the adopted systemic velocity of ∼7 km s{sup –1} for NGC 1333. They also showed time variabilities in both intensity and velocity from multi-epoch observations and an anti-correlation between the intensities of the blue- and redshifted velocity components. We suggest that the unidentified power source of these masers might be found in the earliest evolutionary stage of star formation, before the onset of molecular outflows. Finding this kind of water maser is only possible through an unbiased blind survey. In the 44 GHz methanol maser survey with a sensitivity of σ ∼ 0.5 Jy, we confirmed masers toward IRAS4A2 and the eastern shock region of IRAS2A. Both sources are also detected in 95 and 132 GHz methanol maser lines. In addition, we had new detections of methanol masers at 95 and 132 GHz toward IRAS4B. In terms of the isotropic luminosity, we detected methanol maser sources brighter than ∼5 × 10{sup 25} erg s{sup –1} from our unbiased survey.

  3. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Tax on insurance companies (other than life or...-3 Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual... insurance companies, other than life or mutual or foreign insurance companies not carrying on an...

  4. An Example of an Improvable Rao–Blackwell Improvement, Inefficient Maximum Likelihood Estimator, and Unbiased Generalized Bayes Estimator

    PubMed Central

    Galili, Tal; Meilijson, Isaac

    2016-01-01

    The Rao–Blackwell theorem offers a procedure for converting a crude unbiased estimator of a parameter θ into a “better” one, in fact unique and optimal if the improvement is based on a minimal sufficient statistic that is complete. In contrast, behind every minimal sufficient statistic that is not complete, there is an improvable Rao–Blackwell improvement. This is illustrated via a simple example based on the uniform distribution, in which a rather natural Rao–Blackwell improvement is uniformly improvable. Furthermore, in this example the maximum likelihood estimator is inefficient, and an unbiased generalized Bayes estimator performs exceptionally well. Counterexamples of this sort can be useful didactic tools for explaining the true nature of a methodology and possible consequences when some of the assumptions are violated. [Received December 2014. Revised September 2015.

  5. Biased and unbiased strategies to identify biologically active small molecules.

    PubMed

    Abet, Valentina; Mariani, Angelica; Truscott, Fiona R; Britton, Sébastien; Rodriguez, Raphaël

    2014-08-15

    Small molecules are central players in chemical biology studies. They promote the perturbation of cellular processes underlying diseases and enable the identification of biological targets that can be validated for therapeutic intervention. Small molecules have been shown to accurately tune a single function of pluripotent proteins in a reversible manner with exceptional temporal resolution. The identification of molecular probes and drugs remains a worthy challenge that can be addressed by the use of biased and unbiased strategies. Hypothesis-driven methodologies employs a known biological target to synthesize complementary hits while discovery-driven strategies offer the additional means of identifying previously unanticipated biological targets. This review article provides a general overview of recent synthetic frameworks that gave rise to an impressive arsenal of biologically active small molecules with unprecedented cellular mechanisms. PMID:24811300

  6. Maximum likelihood: Extracting unbiased information from complex networks

    NASA Astrophysics Data System (ADS)

    Garlaschelli, Diego; Loffredo, Maria I.

    2008-07-01

    The choice of free parameters in network models is subjective, since it depends on what topological properties are being monitored. However, we show that the maximum likelihood (ML) principle indicates a unique, statistically rigorous parameter choice, associated with a well-defined topological feature. We then find that, if the ML condition is incompatible with the built-in parameter choice, network models turn out to be intrinsically ill defined or biased. To overcome this problem, we construct a class of safely unbiased models. We also propose an extension of these results that leads to the fascinating possibility to extract, only from topological data, the “hidden variables” underlying network organization, making them “no longer hidden.” We test our method on World Trade Web data, where we recover the empirical gross domestic product using only topological information.

  7. Unbiased sampling of globular lattice proteins in three dimensions.

    PubMed

    Jacobsen, Jesper Lykke

    2008-03-21

    We present a Monte Carlo method that allows efficient and unbiased sampling of Hamiltonian walks on a cubic lattice. Such walks are self-avoiding and visit each lattice site exactly once. They are often used as simple models of globular proteins, upon adding suitable local interactions. Our algorithm can easily be equipped with such interactions, but we study here mainly the flexible homopolymer case where each conformation is generated with uniform probability. We argue that the algorithm is ergodic and has dynamical exponent z=0. We then use it to study polymers of size up to 64(3)=262 144 monomers. Results are presented for the effective interaction between end points, and the interaction with the boundaries of the system. PMID:18517831

  8. 31 CFR 1024.220 - Customer identification programs for mutual funds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information available, and the mutual fund's customer base. At a minimum, these procedures must contain the... mutual fund must retain the information in paragraph (a)(3)(i)(A) of this section for five years after the date the account is closed. The mutual fund must retain the information in paragraphs...

  9. 31 CFR 1024.220 - Customer identification programs for mutual funds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information available, and the mutual fund's customer base. At a minimum, these procedures must contain the... mutual fund must retain the information in paragraph (a)(3)(i)(A) of this section for five years after the date the account is closed. The mutual fund must retain the information in paragraphs...

  10. 31 CFR 1024.220 - Customer identification programs for mutual funds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information available, and the mutual fund's customer base. At a minimum, these procedures must contain the... mutual fund must retain the information in paragraph (a)(3)(i)(A) of this section for five years after the date the account is closed. The mutual fund must retain the information in paragraphs...

  11. 31 CFR 1024.220 - Customer identification programs for mutual funds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information available, and the mutual fund's customer base. At a minimum, these procedures must contain the... mutual fund must retain the information in paragraph (a)(3)(i)(A) of this section for five years after the date the account is closed. The mutual fund must retain the information in paragraphs...

  12. Viscosity and mutual diffusion in strongly asymmetric plasma mixtures

    SciTech Connect

    Bastea, S

    2004-09-07

    The authors present molecular dynamics simulation results for the viscosity and mutual diffusion constant of a strongly asymmetric two-component plasma (TCP). They compare the results with available theoretical models previously tested for much smaller asymmetries. for the case of viscosity they propose a new predictive framework based on the linear mixing rule, while for mutual diffusion they point out some consistency problems of widely used Boltzmann equation based models.

  13. Automotive radar - investigation of mutual interference mechanisms

    NASA Astrophysics Data System (ADS)

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  14. Hierarchical clustering using mutual information

    NASA Astrophysics Data System (ADS)

    Kraskov, A.; Stögbauer, H.; Andrzejak, R. G.; Grassberger, P.

    2005-04-01

    We present a conceptually simple method for hierarchical clustering of data called mutual information clustering (MIC) algorithm. It uses mutual information (MI) as a similarity measure and exploits its grouping property: The MI between three objects X, Y, and Z is equal to the sum of the MI between X and Y, plus the MI between Z and the combined object (XY). We use this both in the Shannon (probabilistic) version of information theory and in the Kolmogorov (algorithmic) version. We apply our method to the construction of phylogenetic trees from mitochondrial DNA sequences and to the output of independent components analysis (ICA) as illustrated with the ECG of a pregnant woman.

  15. Unbiased free energy estimates in fast nonequilibrium transformations using Gaussian mixtures

    SciTech Connect

    Procacci, Piero

    2015-04-21

    In this paper, we present an improved method for obtaining unbiased estimates of the free energy difference between two thermodynamic states using the work distribution measured in nonequilibrium driven experiments connecting these states. The method is based on the assumption that any observed work distribution is given by a mixture of Gaussian distributions, whose normal components are identical in either direction of the nonequilibrium process, with weights regulated by the Crooks theorem. Using the prototypical example for the driven unfolding/folding of deca-alanine, we show that the predicted behavior of the forward and reverse work distributions, assuming a combination of only two Gaussian components with Crooks derived weights, explains surprisingly well the striking asymmetry in the observed distributions at fast pulling speeds. The proposed methodology opens the way for a perfectly parallel implementation of Jarzynski-based free energy calculations in complex systems.

  16. Mutual information analysis of JPEG2000 contexts

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Karam, Lina J.

    2003-05-01

    Context-based arithmetic coding has been widely adopted in image and video compression and is a key component of the new JPEG2000 image compression standard. In this paper, the contexts used in JPEG2000 are analyzed using the mutual information, which has a direct link with the compression performance. We first show that, when combining the contexts, the mutual information between the contexts and the encoded data will decrease unless the conditional probability distributions of the combined contexts are the same. Given I, the initial number of contexts, and F, the final desired number of contexts, there are S(I, F) possible context classification schemes where S(I, F) is called the Stirling number of the second kind. The optimal classification scheme is the one that gives the maximum mutual information. Instead of exhaustive search, the optimal classification scheme can be obtained through a modified Generalized Lloyd algorithm with the relative entropy as the distortion metric. For binary arithmetic coding, the search complexity can be reduced by using the dynamic programming. Our experimental results show that the JPEG2000 contexts capture very well the correlations among the wavelet coefficients. At the same time, the number of contexts used as part of the standard can be reduced without loss in the coding performance.

  17. Mutual Gains Means Everyone Wins.

    ERIC Educational Resources Information Center

    Flaherty, Bernard L.

    1997-01-01

    Mutual gains negotiation is an innovative system that emphasizes interests instead of positions and problem solving instead of preconceived solutions. The process can reverse social disintegration, reverse worker alienation, and address a shifting educational environment. It can resolve difficult labor-management problems such as contracting out,…

  18. Mutual Respect and Civic Education

    ERIC Educational Resources Information Center

    Bird, Colin

    2010-01-01

    Contemporary theories of civic education frequently appeal to an ideal of mutual respect in the context of ethical, ethical and religious disagreement. This paper critically examines two recently popular criticisms of this ideal. The first, coming from a postmodern direction, charges that the ideal is hypocritical in its effort to be maximally…

  19. Cluster-span threshold: An unbiased threshold for binarising weighted complete networks in functional connectivity analysis.

    PubMed

    Smith, Keith; Azami, Hamed; Parra, Mario A; Starr, John M; Escudero, Javier

    2015-08-01

    We propose a new unbiased threshold for network analysis named the Cluster-Span Threshold (CST). This is based on the clustering coefficient, C, following logic that a balance of `clustering' to `spanning' triples results in a useful topology for network analysis and that the product of complementing properties has a unique value only when perfectly balanced. We threshold networks by fixing C at this balanced value, rather than fixing connection density at an arbitrary value, as has been the trend. We compare results from an electroencephalogram data set of volunteers performing visual short term memory tasks of the CST alongside other thresholds, including maximum spanning trees. We find that the CST holds as a sensitive threshold for distinguishing differences in the functional connectivity between tasks. This provides a sensitive and objective method for setting a threshold on weighted complete networks which may prove influential on the future of functional connectivity research. PMID:26736883

  20. FALCON: fast and unbiased reconstruction of high-density super-resolution microscopy data

    PubMed Central

    Min, Junhong; Vonesch, Cédric; Kirshner, Hagai; Carlini, Lina; Olivier, Nicolas; Holden, Seamus; Manley, Suliana; Ye, Jong Chul; Unser, Michael

    2014-01-01

    Super resolution microscopy such as STORM and (F)PALM is now a well known method for biological studies at the nanometer scale. However, conventional imaging schemes based on sparse activation of photo-switchable fluorescent probes have inherently slow temporal resolution which is a serious limitation when investigating live-cell dynamics. Here, we present an algorithm for high-density super-resolution microscopy which combines a sparsity-promoting formulation with a Taylor series approximation of the PSF. Our algorithm is designed to provide unbiased localization on continuous space and high recall rates for high-density imaging, and to have orders-of-magnitude shorter run times compared to previous high-density algorithms. We validated our algorithm on both simulated and experimental data, and demonstrated live-cell imaging with temporal resolution of 2.5 seconds by recovering fast ER dynamics. PMID:24694686

  1. Unbiased contaminant removal for 3D galaxy power spectrum measurements

    NASA Astrophysics Data System (ADS)

    Kalus, B.; Percival, W. J.; Bacon, D. J.; Samushia, L.

    2016-08-01

    We assess and develop techniques to remove contaminants when calculating the 3D galaxy power spectrum. We separate the process into three separate stages: (i) removing the contaminant signal, (ii) estimating the uncontaminated cosmological power spectrum, (iii) debiasing the resulting estimates. For (i), we show that removing the best-fit contaminant (mode subtraction), and setting the contaminated components of the covariance to be infinite (mode deprojection) are mathematically equivalent. For (ii), performing a Quadratic Maximum Likelihood (QML) estimate after mode deprojection gives an optimal unbiased solution, although it requires the manipulation of large N_mode^2 matrices (Nmode being the total number of modes), which is unfeasible for recent 3D galaxy surveys. Measuring a binned average of the modes for (ii) as proposed by Feldman, Kaiser & Peacock (1994, FKP) is faster and simpler, but is sub-optimal and gives rise to a biased solution. We present a method to debias the resulting FKP measurements that does not require any large matrix calculations. We argue that the sub-optimality of the FKP estimator compared with the QML estimator, caused by contaminants is less severe than that commonly ignored due to the survey window.

  2. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Tax on insurance companies (other than life or... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance...) All insurance companies, other than life or mutual or foreign insurance companies not carrying on...

  3. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Tax on insurance companies (other than life or... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance...) All insurance companies, other than life or mutual or foreign insurance companies not carrying on...

  4. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Tax on insurance companies (other than life or... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance...) All insurance companies, other than life or mutual or foreign insurance companies not carrying on...

  5. 26 CFR 1.831-3 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Tax on insurance companies (other than life or... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance...) All insurance companies, other than life or mutual or foreign insurance companies not carrying on...

  6. Mutual impedance computation between printed dipoles

    NASA Astrophysics Data System (ADS)

    Alexopoulos, N. G.; Rana, I. E.

    1981-01-01

    The mutual impedance between microstrip dipoles printed on a grounded substrate is computed. Results for the microstrip dipoles in broadside, collinear, and echelon arrangements are presented. The significance of surface wave to mutual coupling is discussed.

  7. Pluto-charon mutual events

    SciTech Connect

    Binzel, R.P. )

    1989-11-01

    Since 1985, planetary astronomers have been working to take advantage of a once-per-century apparent alignment between Pluto and its satellite, Charon, which has allowed mutual occultation and transit events to be observed. There events, which will cease in 1990, have permitted the first precise determinations of their individual radii, densities, and surface compositions. In addition, information on their surface albedo distributions can be obtained.

  8. UNBIASED INCLINATION DISTRIBUTIONS FOR OBJECTS IN THE KUIPER BELT

    SciTech Connect

    Gulbis, A. A. S.; Elliot, J. L.; Adams, E. R.; Benecchi, S. D.; Buie, M. W.; Trilling, D. E.; Wasserman, L. H. E-mail: jle@mit.ed E-mail: lhw@lowell.ed E-mail: buie@boulder.swri.ed

    2010-08-15

    Using data from the Deep Ecliptic Survey (DES), we investigate the inclination distributions of objects in the Kuiper Belt. We present a derivation for observational bias removal and use this procedure to generate unbiased inclination distributions for Kuiper Belt objects (KBOs) of different DES dynamical classes, with respect to the Kuiper Belt plane. Consistent with previous results, we find that the inclination distribution for all DES KBOs is well fit by the sum of two Gaussians, or a Gaussian plus a generalized Lorentzian, multiplied by sin i. Approximately 80% of KBOs are in the high-inclination grouping. We find that Classical object inclinations are well fit by sin i multiplied by the sum of two Gaussians, with roughly even distribution between Gaussians of widths 2.0{sup +0.6}{sub -0.5}{sup 0} and 8.1{sup +2.6}{sub -2.1}{sup 0}. Objects in different resonances exhibit different inclination distributions. The inclinations of Scattered objects are best matched by sin i multiplied by a single Gaussian that is centered at 19.1{sup +3.9}{sub -3.6}{sup 0} with a width of 6.9{sup +4.1}{sub -2.7}{sup 0}. Centaur inclinations peak just below 20{sup 0}, with one exceptionally high-inclination object near 80{sup 0}. The currently observed inclination distribution of the Centaurs is not dissimilar to that of the Scattered Extended KBOs and Jupiter-family comets, but is significantly different from the Classical and Resonant KBOs. While the sample sizes of some dynamical classes are still small, these results should begin to serve as a critical diagnostic for models of solar system evolution.

  9. Highly sensitive and unbiased approach for elucidating antibody repertoires.

    PubMed

    Lin, Sherry G; Ba, Zhaoqing; Du, Zhou; Zhang, Yu; Hu, Jiazhi; Alt, Frederick W

    2016-07-12

    Developing B lymphocytes undergo V(D)J recombination to assemble germ-line V, D, and J gene segments into exons that encode the antigen-binding variable region of Ig heavy (H) and light (L) chains. IgH and IgL chains associate to form the B-cell receptor (BCR), which, upon antigen binding, activates B cells to secrete BCR as an antibody. Each of the huge number of clonally independent B cells expresses a unique set of IgH and IgL variable regions. The ability of V(D)J recombination to generate vast primary B-cell repertoires results from a combinatorial assortment of large numbers of different V, D, and J segments, coupled with diversification of the junctions between them to generate the complementary determining region 3 (CDR3) for antigen contact. Approaches to evaluate in depth the content of primary antibody repertoires and, ultimately, to study how they are further molded by secondary mutation and affinity maturation processes are of great importance to the B-cell development, vaccine, and antibody fields. We now describe an unbiased, sensitive, and readily accessible assay, referred to as high-throughput genome-wide translocation sequencing-adapted repertoire sequencing (HTGTS-Rep-seq), to quantify antibody repertoires. HTGTS-Rep-seq quantitatively identifies the vast majority of IgH and IgL V(D)J exons, including their unique CDR3 sequences, from progenitor and mature mouse B lineage cells via the use of specific J primers. HTGTS-Rep-seq also accurately quantifies DJH intermediates and V(D)J exons in either productive or nonproductive configurations. HTGTS-Rep-seq should be useful for studies of human samples, including clonal B-cell expansions, and also for following antibody affinity maturation processes. PMID:27354528

  10. Rethinking mutualism stability: cheaters and the evolution of sanctions.

    PubMed

    Frederickson, Megan E

    2013-12-01

    How cooperation originates and persists in diverse species, from bacteria to multicellular organisms to human societies, is a major question in evolutionary biology. A large literature asks: what prevents selection for cheating within cooperative lineages? In mutualisms, or cooperative interactions between species, feedback between partners often aligns their fitness interests, such that cooperative symbionts receive more benefits from their hosts than uncooperative symbionts. But how do these feedbacks evolve? Cheaters might invade symbiont populations and select for hosts that preferentially reward or associate with cooperators (often termed sanctions or partner choice); hosts might adapt to variation in symbiont quality that does not amount to cheating (e.g., environmental variation); or conditional host responses might exist before cheaters do, making mutualisms stable from the outset. I review evidence from yucca-yucca moth, fig-fig wasp, and legume-rhizobium mutualisms, which are commonly cited as mutualisms stabilized by sanctions. Based on the empirical evidence, it is doubtful that cheaters select for host sanctions in these systems; cheaters are too uncommon. Recognizing that sanctions likely evolved for functions other than retaliation against cheaters offers many insights about mutualism coevolution, and about why mutualism evolves in only some lineages of potential hosts. PMID:24552098

  11. Spectral image analysis of mutual illumination between florescent objects.

    PubMed

    Tominaga, Shoji; Kato, Keiji; Hirai, Keita; Horiuchi, Takahiko

    2016-08-01

    This paper proposes a method for modeling and component estimation of the spectral images of the mutual illumination phenomenon between two fluorescent objects. First, we briefly describe the bispectral characteristics of a single fluorescent object, which are summarized as a Donaldson matrix. We suppose that two fluorescent objects with different bispectral characteristics are located close together under a uniform illumination. Second, we model the mutual illumination between two objects. It is shown that the spectral composition of the mutual illumination is summarized with four components: (1) diffuse reflection, (2) diffuse-diffuse interreflection, (3) fluorescent self-luminescence, and (4) interreflection by mutual fluorescent illumination. Third, we develop algorithms for estimating the spectral image components from the observed images influenced by the mutual illumination. When the exact Donaldson matrices caused by the mutual illumination influence are unknown, we have to solve a non-linear estimation problem to estimate both the spectral functions and the location weights. An iterative algorithm is then proposed to solve the problem based on the alternate estimation of the spectral functions and the location weights. In our experiments, the feasibility of the proposed method is shown in three cases: the known Donaldson matrices, weak interreflection, and strong interreflection. PMID:27505645

  12. Parents Helping Parents: Mutual Parenting Network Handbook.

    ERIC Educational Resources Information Center

    Simkinson, Charles H.; Redmond, Robert F.

    Guidelines for mutual parenting are provided in this handbook. "Mutual parenting" means that everyone in the community shares the responsibility for the safety and well-being of the community's youngsters. Several topics are discussed in the 15 brief chapters of the handbook. Chapters 1 through 3 focus on the formation of a mutual parenting…

  13. 76 FR 20458 - Mutual Holding Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... Office of Thrift Supervision Mutual Holding Company AGENCY: Office of Thrift Supervision (OTS), Treasury... collection. Title of Proposal: Mutual Holding Company. OMB Number: 1550-0072. Form Numbers: MHC-1 (OTS Form... whether the applicant meets the statutory and regulatory criteria to form a mutual holding company...

  14. Generalized mutual information of quantum critical chains

    NASA Astrophysics Data System (ADS)

    Alcaraz, F. C.; Rajabpour, M. A.

    2015-04-01

    We study the generalized mutual information I˜n of the ground state of different critical quantum chains. The generalized mutual information definition that we use is based on the well established concept of the Rényi divergence. We calculate this quantity numerically for several distinct quantum chains having either discrete Z (Q ) symmetries (Q -state Potts model with Q =2 ,3 ,4 and Z (Q ) parafermionic models with Q =5 ,6 ,7 ,8 and also Ashkin-Teller model with different anisotropies) or the U (1 ) continuous symmetries (Klein-Gordon field theory, X X Z and spin-1 Fateev-Zamolodchikov quantum chains with different anisotropies). For the spin chains these calculations were done by expressing the ground-state wave functions in two special bases. Our results indicate some general behavior for particular ranges of values of the parameter n that defines I˜n. For a system, with total size L and subsystem sizes ℓ and L -ℓ , the I˜n has a logarithmic leading behavior given by c/˜n4 log[L/π sin(π/ℓ L ) ] where the coefficient c˜n is linearly dependent on the central charge c of the underlying conformal field theory describing the system's critical properties.

  15. Propagating Resource Constraints Using Mutual Exclusion Reasoning

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Sanchez, Romeo; Do, Minh B.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds for jobs using discrete multi-capacity resources. In this paper we show how mutual exclusion reasoning can be used to propagate time bounds for activities using discrete resources. We show that our technique based on critical path analysis and mutex reasoning is just as effective on unary resources, and also shows that it is more effective on multi-capacity resources, through both examples and empirical study.

  16. Defense mutualisms enhance plant diversification.

    PubMed

    Weber, Marjorie G; Agrawal, Anurag A

    2014-11-18

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  17. Defense mutualisms enhance plant diversification

    PubMed Central

    Weber, Marjorie G.; Agrawal, Anurag A.

    2014-01-01

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity. PMID:25349406

  18. Population dynamics and mutualism: Functional responses of benefits and costs

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.; Bronstein, Judith L.

    2002-01-01

    We develop an approach for studying population dynamics resulting from mutualism by employing functional responses based on density‐dependent benefits and costs. These functional responses express how the population growth rate of a mutualist is modified by the density of its partner. We present several possible dependencies of gross benefits and costs, and hence net effects, to a mutualist as functions of the density of its partner. Net effects to mutualists are likely a monotonically saturating or unimodal function of the density of their partner. We show that fundamental differences in the growth, limitation, and dynamics of a population can occur when net effects to that population change linearly, unimodally, or in a saturating fashion. We use the mutualism between senita cactus and its pollinating seed‐eating moth as an example to show the influence of different benefit and cost functional responses on population dynamics and stability of mutualisms. We investigated two mechanisms that may alter this mutualism's functional responses: distribution of eggs among flowers and fruit abortion. Differences in how benefits and costs vary with density can alter the stability of this mutualism. In particular, fruit abortion may allow for a stable equilibrium where none could otherwise exist.

  19. Mutual information in classical spin models

    NASA Astrophysics Data System (ADS)

    Wilms, Johannes; Troyer, Matthias; Verstraete, Frank

    2011-10-01

    The total many-body correlations present in finite temperature classical spin systems are studied using the concept of mutual information. As opposed to zero-temperature quantum phase transitions, the total correlations are not maximal at the phase transition, but reach a maximum in the high-temperature paramagnetic phase. The Shannon mutual information and the Renyi mutual information in both Ising and Potts models in two dimensions are calculated numerically by combining matrix product state algorithms and Monte Carlo sampling techniques.

  20. Mutual enhancement of diverse terminologies

    PubMed Central

    Hardiker, Nicholas R.; Casey, Anne; Coenen, Amy; Konicek, Debra

    2006-01-01

    The purpose of this study was to map the North American Nursing Diagnosis Association (NANDA) nursing diagnoses to the International Classification for Nursing Practice Version 1.0 (ICNP®) and to compare the resulting representations and relationships to those within SNOMED® Clinical Terms (CT). Independent reviewers reached agreement on 25 (i.e. 64%) of the 39 parent-child relationships identified via the mappings between NANDA entities. Other parent-child relationships were more questionable and are in need of further discussion. This work does not seek to promote one terminology over any other. Rather, this collaborative effort has the potential to mutually enhance all three terminologies involved in the study: ICNP®, SNOMED® CT and NANDA. In doing so it provides an example of the type of collaborative effort that is needed to facilitate the development of tools to support interoperability at a global level. PMID:17238355

  1. High levels of absorption in orientation-unbiased, radio-selected 3CR Active Galaxies

    NASA Astrophysics Data System (ADS)

    Wilkes, Belinda J.; Haas, Martin; Barthel, Peter; Leipski, Christian; Kuraszkiewicz, Joanna; Worrall, Diana; Birkinshaw, Mark; Willner, Steven P.

    2014-08-01

    A critical problem in understanding active galaxies (AGN) is the separation of intrinsic physical differences from observed differences that are due to orientation. Obscuration of the active nucleus is anisotropic and strongly frequency dependent leading to complex selection effects for observations in most wavebands. These can only be quantified using a sample that is sufficiently unbiased to test orientation effects. Low-frequency radio emission is one way to select a close-to orientation-unbiased sample, albeit limited to the minority of AGN with strong radio emission.Recent Chandra, Spitzer and Herschel observations combined with multi-wavelength data for a complete sample of high-redshift (1 24.2) = 2.5:1.4:1 in these high-luminosity (log L(0.3-8keV) ~ 44-46) sources. These ratios are consistent with current expectations based on modelingthe Cosmic X-ray Background. A strong correlation with radio orientation constrains the geometry of the obscuring disk/torus to have a ~60 degree opening angle and ~12 degree Compton-thick cross-section. The deduced ~50% obscured fraction of the population contrasts with typical estimates of ~20% obscured in optically- and X-ray-selected high-luminosity samples. Once the primary nuclear emission is obscured, AGN X-ray spectra are frequently dominated by unobscured non-nuclear or scattered nuclear emission which cannot be distinguished from direct nuclear emission with a lower obscuration level unless high quality data is available. As a result, both the level of obscuration and the estimated instrinsic luminosities of highly-obscured AGN are likely to be significantly (*10-1000) underestimated for 25-50% of the population. This may explain the lower obscured fractions reported for optical and X-ray samples which have no independent measure of the AGN

  2. Lessons learned from two peer-led mutual support groups.

    PubMed

    Viverito, Kristen M; Cardin, Scott A; Johnson, Leigh Ann; Owen, Richard R

    2013-10-01

    This case report and analysis describe the formation of two peer-led mutual support groups conducted within the context of a Veterans Administration Medical Center. Based on our assessment of the success of one of these groups and the failure of the other, we offer several recommendations and suggestions to help promote this modality. More specifically, we hypothesize that such groups are more likely to be successful (1) if participants are transferred en masse from another group, (2) that, at least initially, housing the group in the same context as formal clinician-led groups or overlapping clinician-led and peer-led groups may help smooth the transition from authority-led treatment to a mutual peer support format, and finally, (3) that prior experiences in interpersonal process groups may promote the skills and cohesion to promote successful transition to mutual support. PMID:24004015

  3. Empirical study of the tails of mutual fund size

    NASA Astrophysics Data System (ADS)

    Schwarzkopf, Yonathan; Farmer, J. Doyne

    2010-06-01

    The mutual fund industry manages about a quarter of the assets in the U.S. stock market and thus plays an important role in the U.S. economy. The question of how much control is concentrated in the hands of the largest players is best quantitatively discussed in terms of the tail behavior of the mutual fund size distribution. We study the distribution empirically and show that the tail is much better described by a log-normal than a power law, indicating less concentration than, for example, personal income. The results are highly statistically significant and are consistent across fifteen years. This contradicts a recent theory concerning the origin of the power law tails of the trading volume distribution. Based on the analysis in a companion paper, the log-normality is to be expected, and indicates that the distribution of mutual funds remains perpetually out of equilibrium.

  4. Unraveling cognitive traits using the Morris water maze unbiased strategy classification (MUST-C) algorithm.

    PubMed

    Illouz, Tomer; Madar, Ravit; Louzon, Yoram; Griffioen, Kathleen J; Okun, Eitan

    2016-02-01

    The assessment of spatial cognitive learning in rodents is a central approach in neuroscience, as it enables one to assess and quantify the effects of treatments and genetic manipulations from a broad perspective. Although the Morris water maze (MWM) is a well-validated paradigm for testing spatial learning abilities, manual categorization of performance in the MWM into behavioral strategies is subject to individual interpretation, and thus to biases. Here we offer a support vector machine (SVM) - based, automated, MWM unbiased strategy classification (MUST-C) algorithm, as well as a cognitive score scale. This model was examined and validated by analyzing data obtained from five MWM experiments with changing platform sizes, revealing a limitation in the spatial capacity of the hippocampus. We have further employed this algorithm to extract novel mechanistic insights on the impact of members of the Toll-like receptor pathway on cognitive spatial learning and memory. The MUST-C algorithm can greatly benefit MWM users as it provides a standardized method of strategy classification as well as a cognitive scoring scale, which cannot be derived from typical analysis of MWM data. PMID:26522398

  5. A Grand Challenge: Unbiased Phenotypic Function of Metabolites from Jaspis splendens against Parkinson's Disease.

    PubMed

    Wang, Dongdong; Feng, Yunjiang; Murtaza, Mariyam; Wood, Stephen; Mellick, George; Hooper, John N A; Quinn, Ronald J

    2016-02-26

    A grand challenge in natural product chemistry is to determine the biological effects of all natural products. A phenotypic approach is frequently used for determining the activity of a compound and its potential impact on a disease state. Chemical investigation of a specimen of Jaspis splendens collected from the Great Barrier Reef resulted in the isolation of a new pterin derivative, jaspterin (1), a new bisindole alkaloid, splendamide (2), and a new imidazole alkaloid, jaspnin A (3) TFA salt. Jaspamycin (8) and 6-bromo-1H-indole-3-carboximidamide (16) are reported for the first time as naturally occurring metabolites. Known nucleosides (4-7, 9, 10), aglycones (11-13), indole alkaloids (14, 15, 17), and jaspamide peptides (18-22) were also isolated. The structures of the three new compounds 1-3 were unambiguously elucidated based on NMR and mass spectroscopic data. Jaspnin A (3) contained a rare thiomethylated imidazolinium unit. Coupling an unbiased phenotypic assay using a human olfactory neurosphere-derived cell model of Parkinson's disease to all of the natural products from the species J. splendens allowed the phenotypic profiles of the metabolites to be investigated. PMID:26883470

  6. Unbiased Feature Selection in Learning Random Forests for High-Dimensional Data

    PubMed Central

    Nguyen, Thanh-Tung; Huang, Joshua Zhexue; Nguyen, Thuy Thi

    2015-01-01

    Random forests (RFs) have been widely used as a powerful classification method. However, with the randomization in both bagging samples and feature selection, the trees in the forest tend to select uninformative features for node splitting. This makes RFs have poor accuracy when working with high-dimensional data. Besides that, RFs have bias in the feature selection process where multivalued features are favored. Aiming at debiasing feature selection in RFs, we propose a new RF algorithm, called xRF, to select good features in learning RFs for high-dimensional data. We first remove the uninformative features using p-value assessment, and the subset of unbiased features is then selected based on some statistical measures. This feature subset is then partitioned into two subsets. A feature weighting sampling technique is used to sample features from these two subsets for building trees. This approach enables one to generate more accurate trees, while allowing one to reduce dimensionality and the amount of data needed for learning RFs. An extensive set of experiments has been conducted on 47 high-dimensional real-world datasets including image datasets. The experimental results have shown that RFs with the proposed approach outperformed the existing random forests in increasing the accuracy and the AUC measures. PMID:25879059

  7. Automated and unbiased classification of chemical profiles from fungi using high performance liquid chromatography.

    PubMed

    Hansen, Michael Edberg; Andersen, Birgitte; Smedsgaard, Jørn

    2005-06-01

    In this paper we present a method for unbiased/unsupervised classification and identification of closely related fungi, using chemical analysis of secondary metabolite profiles created by HPLC with UV diode array detection. For two chromatographic data matrices a vector of locally aligned full spectral similarities is calculated along the retention time axis. The vector depicts the evaluating of the alikeness between two fungal extracts based upon eluted compounds and corresponding UV-absorbance spectra. For assessment of the chemotaxonomic grouping the vector is condensed to one similarity describing the overall degree of similarity between the profiles. Two sets of data were used in this study: One set was used in the method development and a second dataset used for method validation. First we developed a method for evaluating the secondary metabolite production from closely related Penicillium species. Then the algorithm was validated on fungal isolates belonging to the genus Alternaria. The results showed that the species may be segregated into taxa in full accordance with published taxonomy. PMID:15767006

  8. Unbiased Rare Event Sampling in Spatial Stochastic Systems Biology Models Using a Weighted Ensemble of Trajectories

    PubMed Central

    Donovan, Rory M.; Tapia, Jose-Juan; Sullivan, Devin P.; Faeder, James R.; Murphy, Robert F.; Dittrich, Markus; Zuckerman, Daniel M.

    2016-01-01

    The long-term goal of connecting scales in biological simulation can be facilitated by scale-agnostic methods. We demonstrate that the weighted ensemble (WE) strategy, initially developed for molecular simulations, applies effectively to spatially resolved cell-scale simulations. The WE approach runs an ensemble of parallel trajectories with assigned weights and uses a statistical resampling strategy of replicating and pruning trajectories to focus computational effort on difficult-to-sample regions. The method can also generate unbiased estimates of non-equilibrium and equilibrium observables, sometimes with significantly less aggregate computing time than would be possible using standard parallelization. Here, we use WE to orchestrate particle-based kinetic Monte Carlo simulations, which include spatial geometry (e.g., of organelles, plasma membrane) and biochemical interactions among mobile molecular species. We study a series of models exhibiting spatial, temporal and biochemical complexity and show that although WE has important limitations, it can achieve performance significantly exceeding standard parallel simulation—by orders of magnitude for some observables. PMID:26845334

  9. Institutionalized Mutuality in Canada-China Management Education Collaboration

    ERIC Educational Resources Information Center

    Wei, Shuguang; Liu, Xianjun

    2015-01-01

    This paper examines the Canada-China Management Education Program (CCMEP, 1983-1996) between the University of Toronto (UT) and Huazhong University of Science and Technology (HUST). In this paper, we create a "Three Levels/Four Parameters" analytical framework, based on the concept of mutuality from Johan Galtung (1980) and the concept…

  10. The Environment of Classification: The Concept of Mutual Exclusivity

    ERIC Educational Resources Information Center

    Jones, Kevin P.

    1973-01-01

    Classification is interpreted so as to incorporate all attempts at the imposition of order upon our observations of the universe. In this article, the fundamental bases of classification are examined: in particular the alien notions of mutual exclusivity and the use of inflexible structures to mirror a dynamic universe. (26 references) (Author/KE)

  11. The Competitive Strategy of Mutual Learning.

    ERIC Educational Resources Information Center

    Kelner, Stephen P.; Slavin, Lois

    1998-01-01

    Defines and discusses mutual learning in organizations. Suggests that the idea of people and companies sharing knowledge is becoming a competitive strategy because mutual learning enables executives and employees to increase their capacity to work together, accelerate organizational learning, and avoid mistakes. (JOW)

  12. Victimization within Mutually Antipathetic Peer Relationships

    ERIC Educational Resources Information Center

    Card, Noel A.; Hodges, Ernest V. E.

    2007-01-01

    Children's victimization experiences within relationships characterized by mutual animosity were examined among 210 6th- and 7th-grade boys and girls. Participants reported that a greater proportion of mutual antipathies, relative to other peers, victimized them. Moreover, the receipt of victimization within antipathetic relationships was greater…

  13. Quadratic mutual information for dimensionality reduction and classification

    NASA Astrophysics Data System (ADS)

    Gray, David M.; Principe, José C.

    2010-04-01

    A research area based on the application of information theory to machine learning has attracted considerable interest in the last few years. This research area has been coined information-theoretic learning within the community. In this paper we apply elements of information-theoretic learning to the problem of automatic target recognition (ATR). A number of researchers have previously shown the benefits of designing classifiers based on maximizing the mutual information between the class data and the class labels. Following prior research in information-theoretic learning, in the current results we show that quadratic mutual information, derived using a special case of the more general Renyi's entropy, can be used for classifier design. In this implementation, a simple subspace projection classifier is formulated to find the optimal projection weights such that the quadratic mutual information between the class data and the class labels is maximized. This subspace projection accomplishes a dimensionality reduction of the raw data set wherein information about the class membership is retained while irrelevant information is discarded. A subspace projection based on this criterion preserves as much class discriminability as possible within the subspace. For this paper, laser radar images are used to demonstrate the results. Classification performance against this data set is compared for a gradient descent MLP classifier and a quadratic mutual information MLP classifier.

  14. [Maintaining solidarity: is mutuality the solution?].

    PubMed

    Gevers, J K M; Ploem, M C

    2013-01-01

    Solidarity is essentially the willingness to contribute to the community and its demands, which may even involve contributing more than one is expecting to receive. Another principle is mutuality: this refers to a balance between rights and obligations or between mutual obligations. In its advisory document 'The importance of mutuality......solidarity takes work!', The Dutch Council for Public Health and Health Care underlines the importance of ensuring solidarity within the Dutch health care system, e.g. by encouraging patients to take responsibility for their own health, possibly by introducing elements of mutuality. In our contribution, we comment on the Council's advice. Although we fully agree with the overall conclusion that solidarity should be maintained within the system, we do not see how the introduction of increased mutuality will contribute to this goal. PMID:23945438

  15. Two-Level Document Ranking Using Mutual Information in Natural Language Information Retrieval.

    ERIC Educational Resources Information Center

    Kang, Hyun-Kyu; Choi, Key-Sun

    1997-01-01

    Discussion of information retrieval and relevance focuses on mutual information, a measure which represents the relation between two words. A model of a natural-language information-retrieval system that is based on a two-level document-ranking method using mutual information is presented, and a Korean encyclopedia test collection is explained.…

  16. Mutual Orbits of Transneptunian Binaries

    NASA Astrophysics Data System (ADS)

    Grundy, William M.; Noll, K. S.; Roe, H. G.; Porter, S. B.; Trujillo, C. A.; Benecchi, S. D.; Buie, M. W.

    2012-10-01

    We report the latest results from a program of high spatial resolution imaging to resolve the individual components of binary transneptunian objects. These observations use Hubble Space Telescope and also laser guide star adaptive optics systems on Keck and Gemini telescopes on Mauna Kea. From relative astrometry over multiple epochs, we determine the mutual orbits of the components, and thus the total masses of the systems. Accurate masses anchor subsequent detailed investigations into the physical characteristics of these systems. For instance, dynamical masses enable computation of bulk densities for systems where the component sizes can be estimated from other measurements. Additionally, patterns in the ensemble characteristics of binary orbits offer clues to circumstances in the protoplanetary nebula when these systems formed, as well as carrying imprints of various subsequent dynamical evolution processes. The growing ensemble of known orbits shows intriguing patterns that can shed light on the evolution of this population of distant objects. This work has been supported by an NSF Planetary Astronomy grant and by several Hubble Space Telescope and NASA Keck data analysis grants. The research makes use of data from the Gemini Observatory obtained through NOAO survey program 11A-0017, from a large number of Hubble Space Telescope programs, and from several NASA Keck programs.

  17. 12 CFR 575.3 - Mutual holding company reorganizations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Mutual holding company reorganizations. 575.3... COMPANIES § 575.3 Mutual holding company reorganizations. A mutual savings association may reorganize to become a mutual holding company, or join in a mutual holding company reorganization as an...

  18. Mutual coupling, channel model, and BER for curvilinear antenna arrays

    NASA Astrophysics Data System (ADS)

    Huang, Zhiyong

    interferers, Doppler spread and convergence are investigated. The tracking mode is introduced to the adaptive array system, and it further improves the BER. The benefit of using faster data rate (wider bandwidth) is discussed. In order to have better performance in a 3D space, the geometries of uniform spherical array (USAs) are presented and different configurations of USAs are discussed. The LMS algorithm based on temporal a priori information is applied to UCAs and USAs to beamform the patterns. Their performances are compared based on simulation results. Based on the analytical and simulation results, it can be concluded that mutual coupling slightly influences the performance of the adaptive array in communication systems. In addition, arrays with curvilinear geometries perform well in AWGN and fading channels.

  19. Generalized mutual information and Tsirelson's bound

    SciTech Connect

    Wakakuwa, Eyuri; Murao, Mio

    2014-12-04

    We introduce a generalization of the quantum mutual information between a classical system and a quantum system into the mutual information between a classical system and a system described by general probabilistic theories. We apply this generalized mutual information (GMI) to a derivation of Tsirelson's bound from information causality, and prove that Tsirelson's bound can be derived from the chain rule of the GMI. By using the GMI, we formulate the 'no-supersignalling condition' (NSS), that the assistance of correlations does not enhance the capability of classical communication. We prove that NSS is never violated in any no-signalling theory.

  20. Inhibitory impact of 3'-terminal 2'-O-methylated small silencing RNA on target-primed polymerization and unbiased amplified quantification of the RNA in Arabidopsis thaliana.

    PubMed

    Chen, Feng; Fan, Chunhai; Zhao, Yongxi

    2015-09-01

    3'-terminal 2'-O-methylation has been found in several kinds of small silencing RNA, regarded as a protective mechanism against enzymatic 3' → 5' degradation and 3'-end uridylation. The influence of this modification on enzymatic polymerization, however, remains unknown. Herein, a systematic investigation is performed to explore this issue. We found these methylated small RNAs exhibited a suppression behavior in target-primed polymerization, revealing biased result for the manipulation of these small RNAs by conventional polymerization-based methodology. The related potential mechanism is investigated and discussed, which is probably ascribed to the big size of modified group and its close location to 3'-OH. Furthermore, two novel solutions each utilizing base-stacking hybridization and three-way junction structure have been proposed to realize unbiased recognition of small RNAs. On the basis of phosphorothioate against nicking, a creative amplified strategy, phosphorothioate-protected polymerization/binicking amplification, has also been developed for the unbiased quantification of methylated small RNA in Arabidopsis thaliana, demonstrating its promising potential for real sample analysis. Collectively, our studies uncover the polymerization inhibition by 3'-terminal 2'-O-methylated small RNAs with mechanistic discussion, and propose novel unbiased solutions for amplified quantification of small RNAs in real sample. PMID:26244621

  1. Estimating Unbiased Treatment Effects in Education Using a Regression Discontinuity Design

    ERIC Educational Resources Information Center

    Smith, William C.

    2014-01-01

    The ability of regression discontinuity (RD) designs to provide an unbiased treatment effect while overcoming the ethical concerns plagued by Random Control Trials (RCTs) make it a valuable and useful approach in education evaluation. RD is the only explicitly recognized quasi-experimental approach identified by the Institute of Education…

  2. A Derivation of the Unbiased Standard Error of Estimate: The General Case.

    ERIC Educational Resources Information Center

    O'Brien, Francis J., Jr.

    This paper is part of a series of applied statistics monographs intended to provide supplementary reading for applied statistics students. In the present paper, derivations of the unbiased standard error of estimate for both the raw score and standard score linear models are presented. The derivations for raw score linear models are presented in…

  3. Quantum correlation in degenerate optical parametric oscillators with mutual injections

    NASA Astrophysics Data System (ADS)

    Takata, Kenta; Marandi, Alireza; Yamamoto, Yoshihisa

    2015-10-01

    We theoretically and numerically study the quantum dynamics of two degenerate optical parametric oscillators with mutual injections. The cavity mode in the optical coupling path between the two oscillator facets is explicitly considered. Stochastic equations for the oscillators and mutual injection path based on the positive P representation are derived. The system of two gradually pumped oscillators with out-of-phase mutual injections is simulated, and its quantum state is investigated. When the incoherent loss of the oscillators other than the mutual injections is small, the squeezed quadratic amplitudes p ̂ in the oscillators are positively correlated near the oscillation threshold. It indicates finite quantum correlation, estimated via Gaussian quantum discord, and the entanglement between the intracavity subharmonic fields. When the loss in the injection path is low, each oscillator around the phase transition point forms macroscopic superposition even under a small pump noise. It suggests that the squeezed field stored in the low-loss injection path weakens the decoherence in the oscillators.

  4. Measurement reduction for mutual coupling calibration in DOA estimation

    NASA Astrophysics Data System (ADS)

    Aksoy, Taylan; Tuncer, T. Engin

    2012-01-01

    Mutual coupling is an important source of error in antenna arrays that should be compensated for super resolution direction-of-arrival (DOA) algorithms, such as Multiple Signal Classification (MUSIC) algorithm. A crucial step in array calibration is the determination of the mutual coupling coefficients for the antenna array. In this paper, a system theoretic approach is presented for the mutual coupling characterization of antenna arrays. The comprehension and implementation of this approach is simple leading to further advantages in calibration measurement reduction. In this context, a measurement reduction method for antenna arrays with omni-directional and identical elements is proposed which is based on the symmetry planes in the array geometry. The proposed method significantly decreases the number of measurements during the calibration process. This method is evaluated using different array types whose responses and the mutual coupling characteristics are obtained through numerical electromagnetic simulations. It is shown that a single calibration measurement is sufficient for uniform circular arrays. Certain important and interesting characteristics observed during the experiments are outlined.

  5. 76 FR 71437 - Mutual Savings Association Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ... Office of the Comptroller of the Currency Mutual Savings Association Advisory Committee AGENCY... Mutual Savings Association Advisory Committee (MSAAC or Committee) formerly administered by the Office of... of and challenges facing mutual savings associations. The OCC is seeking nominations of...

  6. Unbiased estimation of chloroplast number in mesophyll cells: advantage of a genuine three-dimensional approach

    PubMed Central

    Kubínová, Zuzana

    2014-01-01

    Chloroplast number per cell is a frequently examined quantitative anatomical parameter, often estimated by counting chloroplast profiles in two-dimensional (2D) sections of mesophyll cells. However, a mesophyll cell is a three-dimensional (3D) structure and this has to be taken into account when quantifying its internal structure. We compared 2D and 3D approaches to chloroplast counting from different points of view: (i) in practical measurements of mesophyll cells of Norway spruce needles, (ii) in a 3D model of a mesophyll cell with chloroplasts, and (iii) using a theoretical analysis. We applied, for the first time, the stereological method of an optical disector based on counting chloroplasts in stacks of spruce needle optical cross-sections acquired by confocal laser-scanning microscopy. This estimate was compared with counting chloroplast profiles in 2D sections from the same stacks of sections. Comparing practical measurements of mesophyll cells, calculations performed in a 3D model of a cell with chloroplasts as well as a theoretical analysis showed that the 2D approach yielded biased results, while the underestimation could be up to 10-fold. We proved that the frequently used method for counting chloroplasts in a mesophyll cell by counting their profiles in 2D sections did not give correct results. We concluded that the present disector method can be efficiently used for unbiased estimation of chloroplast number per mesophyll cell. This should be the method of choice, especially in coniferous needles and leaves with mesophyll cells with lignified cell walls where maceration methods are difficult or impossible to use. PMID:24336344

  7. Onset of immune senescence defined by unbiased pyrosequencing of human immunoglobulin mRNA repertoires.

    PubMed

    Rubelt, Florian; Sievert, Volker; Knaust, Florian; Diener, Christian; Lim, Theam Soon; Skriner, Karl; Klipp, Edda; Reinhardt, Richard; Lehrach, Hans; Konthur, Zoltán

    2012-01-01

    The immune system protects us from foreign substances or pathogens by generating specific antibodies. The variety of immunoglobulin (Ig) paratopes for antigen recognition is a result of the V(D)J rearrangement mechanism, while a fast and efficient immune response is mediated by specific immunoglobulin isotypes obtained through class switch recombination (CSR). To get a better understanding on how antibody-based immune protection works and how it changes with age, the interdependency between these two parameters need to be addressed. Here, we have performed an in depth analysis of antibody repertoires of 14 healthy donors representing different gender and age groups. For this task, we developed a unique pyrosequencing approach, which is able to monitor the expression levels of all immunoglobulin V(D)J recombinations of all isotypes including subtypes in an unbiased and quantitative manner. Our results show that donors have individual immunoglobulin repertoires and cannot be clustered according to V(D)J recombination patterns, neither by age nor gender. However, after incorporating isotype-specific analysis and considering CSR information into hierarchical clustering the situation changes. For the first time the donors cluster according to age and separate into young adults and elderly donors (>50). As a direct consequence, this clustering defines the onset of immune senescence at the age of fifty and beyond. The observed age-dependent reduction of CSR ability proposes a feasible explanation why reduced efficacy of vaccination is seen in the elderly and implies that novel vaccine strategies for the elderly should include the "Golden Agers". PMID:23226220

  8. A/T/N: An unbiased descriptive classification scheme for Alzheimer disease biomarkers.

    PubMed

    Jack, Clifford R; Bennett, David A; Blennow, Kaj; Carrillo, Maria C; Feldman, Howard H; Frisoni, Giovanni B; Hampel, Harald; Jagust, William J; Johnson, Keith A; Knopman, David S; Petersen, Ronald C; Scheltens, Philip; Sperling, Reisa A; Dubois, Bruno

    2016-08-01

    Biomarkers have become an essential component of Alzheimer disease (AD) research and because of the pervasiveness of AD pathology in the elderly, the same biomarkers are used in cognitive aging research. A number of current issues suggest that an unbiased descriptive classification scheme for these biomarkers would be useful. We propose the "A/T/N" system in which 7 major AD biomarkers are divided into 3 binary categories based on the nature of the pathophysiology that each measures. "A" refers to the value of a β-amyloid biomarker (amyloid PET or CSF Aβ42); "T," the value of a tau biomarker (CSF phospho tau, or tau PET); and "N," biomarkers of neurodegeneration or neuronal injury ([(18)F]-fluorodeoxyglucose-PET, structural MRI, or CSF total tau). Each biomarker category is rated as positive or negative. An individual score might appear as A+/T+/N-, or A+/T-/N-, etc. The A/T/N system includes the new modality tau PET. It is agnostic to the temporal ordering of mechanisms underlying AD pathogenesis. It includes all individuals in any population regardless of the mix of biomarker findings and therefore is suited to population studies of cognitive aging. It does not specify disease labels and thus is not a diagnostic classification system. It is a descriptive system for categorizing multidomain biomarker findings at the individual person level in a format that is easy to understand and use. Given the present lack of consensus among AD specialists on terminology across the clinically normal to dementia spectrum, a biomarker classification scheme will have broadest acceptance if it is independent from any one clinically defined diagnostic scheme. PMID:27371494

  9. A/T/N: An unbiased descriptive classification scheme for Alzheimer disease biomarkers

    PubMed Central

    Bennett, David A.; Blennow, Kaj; Carrillo, Maria C.; Feldman, Howard H.; Frisoni, Giovanni B.; Hampel, Harald; Jagust, William J.; Johnson, Keith A.; Knopman, David S.; Petersen, Ronald C.; Scheltens, Philip; Sperling, Reisa A.; Dubois, Bruno

    2016-01-01

    Biomarkers have become an essential component of Alzheimer disease (AD) research and because of the pervasiveness of AD pathology in the elderly, the same biomarkers are used in cognitive aging research. A number of current issues suggest that an unbiased descriptive classification scheme for these biomarkers would be useful. We propose the “A/T/N” system in which 7 major AD biomarkers are divided into 3 binary categories based on the nature of the pathophysiology that each measures. “A” refers to the value of a β-amyloid biomarker (amyloid PET or CSF Aβ42); “T,” the value of a tau biomarker (CSF phospho tau, or tau PET); and “N,” biomarkers of neurodegeneration or neuronal injury ([18F]-fluorodeoxyglucose–PET, structural MRI, or CSF total tau). Each biomarker category is rated as positive or negative. An individual score might appear as A+/T+/N−, or A+/T−/N−, etc. The A/T/N system includes the new modality tau PET. It is agnostic to the temporal ordering of mechanisms underlying AD pathogenesis. It includes all individuals in any population regardless of the mix of biomarker findings and therefore is suited to population studies of cognitive aging. It does not specify disease labels and thus is not a diagnostic classification system. It is a descriptive system for categorizing multidomain biomarker findings at the individual person level in a format that is easy to understand and use. Given the present lack of consensus among AD specialists on terminology across the clinically normal to dementia spectrum, a biomarker classification scheme will have broadest acceptance if it is independent from any one clinically defined diagnostic scheme. PMID:27371494

  10. Mycorrhiza: A Common Form of Mutualism.

    ERIC Educational Resources Information Center

    Medve, Richard J.

    1978-01-01

    Mycorrhizae are among the most common examples of mutualism. This article discusses their structure, symbolic relationship, factors affecting formation and applying research. Questions are posed and answers suggested. (MA)

  11. Phenological shifts and the fate of mutualisms

    PubMed Central

    Rafferty, Nicole E.; CaraDonna, Paul J.; Bronstein, Judith L.

    2014-01-01

    Climate change is altering the timing of life history events in a wide array of species, many of which are involved in mutualistic interactions. Because many mutualisms can form only if partner species are able to locate each other in time, differential phenological shifts are likely to influence their strength, duration and outcome. At the extreme, climate change-driven shifts in phenology may result in phenological mismatch: the partial or complete loss of temporal overlap of mutualistic species. We have a growing understanding of how, when, and why phenological change can alter one type of mutualism–pollination. However, as we show here, there has been a surprising lack of attention to other types of mutualism. We generate a set of predictions about the characteristics that may predispose mutualisms in general to phenological mismatches. We focus not on the consequences of such mismatches but rather on the likelihood that mismatches will develop. We explore the influence of three key characteristics of mutualism: 1) intimacy, 2) seasonality and duration, and 3) obligacy and specificity. We predict that the following characteristics of mutualism may increase the likelihood of phenological mismatch: 1) a non-symbiotic life history in which co-dispersal is absent; 2) brief, seasonal interactions; and 3) facultative, generalized interactions. We then review the limited available data in light of our a priori predictions and point to mutualisms that are more and less likely to be at risk of becoming phenologically mismatched, emphasizing the need for research on mutualisms other than plant–pollinator interactions. Future studies should explicitly focus on mutualism characteristics to determine whether and how changing phenologies will affect mutualistic interactions. PMID:25883391

  12. Unbiased polarized PDFs upgraded with new inclusive DIS data

    NASA Astrophysics Data System (ADS)

    Nocera, Emanuele R.

    2016-02-01

    I present a determination of longitudinally-polarized parton distribution functions of the proton from inclusive deep-inelastic scattering data: NNPDFpol1.0+. This determination, based on the NNPDF methodology, upgrades a previous analysis, NNPDFpol1.0, in two respects: first, it includes all new data sets which have recently become available from the COMPASS experiment at CERN and from the E93-009, EG1-DVCS and E06-014 experiments at JLAB; second, it uses the state-of-the-art unpolarized parton set NNPDF3.0 as a baseline for the reconstruction of fitted observables and for the determination of positivity constraints. I discuss the impact of both these new inputs on the uncertainty of parton distribution functions.

  13. Unbiased degree-preserving randomization of directed binary networks

    NASA Astrophysics Data System (ADS)

    Roberts, E. S.; Coolen, A. C. C.

    2012-04-01

    Randomizing networks using a naive “accept-all” edge-swap algorithm is generally biased. Building on recent results for nondirected graphs, we construct an ergodic detailed balance Markov chain with nontrivial acceptance probabilities for directed graphs, which converges to a strictly uniform measure and is based on edge swaps that conserve all in and out degrees. The acceptance probabilities can also be generalized to define Markov chains that target any alternative desired measure on the space of directed graphs in order to generate graphs with more sophisticated topological features. This is demonstrated by defining a process tailored to the production of directed graphs with specified degree-degree correlation functions. The theory is implemented numerically and tested on synthetic and biological network examples.

  14. Unbiased dynamical and physical characteristics of the near-Earth-object population

    NASA Astrophysics Data System (ADS)

    Granvik, M.; Morbidelli, A.; Jedicke, R.; Bottke, W.; Bolin, B.; Beshore, E.; Delbo, M.; Vokrouhlicky, D.; Penttilä, A.; Nesvorny, D.; Michel, P.

    2014-07-01

    Recent years have witnessed a renewed interest in the population-level characteristics of near-Earth objects (NEOs) in terms of their unbiased orbital and absolute-magnitude distributions. The interest has been driven by the realization that the Bottke et al.NEO model [1,2] has started fraying at the edges after a decade of success. The number of known NEOs is currently about two orders of magnitude larger than the number of calibration targets used for the Bottke model and a new population model is needed to explain the discrepancy between the observed and predicted NEO distributions. The recent update [3] of the Bottke model improved the statistics of the orbital distributions and made some new predictions such as the existence of near-Earth asteroids on retrograde orbits, but did not attempt a full re-calibration of the model. Our new NEO model is an improvement on the approach originally developed by Bottke et al. [1,2]. The orbital distributions for NEOs originating in different regions of the main asteroid belt have been re-computed from scratch. We start with a forward integration of an unbiased sample of known main-belt objects (MBOs) to locate all possible NEO source regions in the main asteroid belt. We then record the orbital evolution of particles that enter the NEO region until they are ejected from the solar system or collide with the Sun or the planets in order to build up the so-called NEO residence-time distributions. We calibrate the model with some 4,550 NEOs detected by the Catalina Sky Survey's (CSS) Mt.Lemmon (G96) and Catalina (703) stations in 2005--2012 during untargeted observations. The nightly detection efficiencies measured by CSS are turned into likelihoods that an NEO with a given semimajor axis 0.6 au < a < 3.5 au, eccentricity 0 < e < 1, inclination 0° < i < 180° and absolute magnitude 15 < H < 25 would have been detected by CSS in the above timeframe. We use a novel, computationally efficient approach to numerically estimate the

  15. An automated hydrodynamic process for controlled, unbiased DNA shearing.

    PubMed

    Thorstenson, Y R; Hunicke-Smith, S P; Oefner, P J; Davis, R W

    1998-08-01

    An automated, inexpensive, easy-to-use, and reproducible technique for controlled, random DNA fragmentation has been developed. The technique is based on point-sink hydrodynamics that result when a DNA sample is forced through a small hole by a syringe pump. Commercially available components are used to reduce the cost and complexity of the instrument. The design is optimized to reduce the volume of sample required and to speed processing time. Shearing of the samples can be completely automated by computer control. Ninety percent of sheared DNA fragments fall within a twofold size distribution that is highly reproducible. Three parameters are critical: the flow geometry, the flow rate, and a minimum number of iterations. Shearing is reproducible over a wide range of temperatures, DNA concentrations, and initial DNA size. The cloning efficiency of the sheared DNA is very good even without end repair, the distribution of assembled sequences is random, and there is no sequence bias at the ends of sheared fragments that have been cloned. The instrument, called the Point-sink Shearer (PtS), has already been exported successfully to many other laboratories. PMID:9724331

  16. Separability conditions based on local fine-grained uncertainty relations

    NASA Astrophysics Data System (ADS)

    Rastegin, Alexey E.

    2016-06-01

    Many protocols of quantum information processing use entangled states. Hence, separability criteria are of great importance. We propose new separability conditions for a bipartite finite-dimensional system. They are derived by using fine-grained uncertainty relations. Fine-grained uncertainty relations can be obtained by consideration of the spectral norms of certain positive matrices. One of possible approaches to separability conditions is connected with upper bounds on the sum of maximal probabilities. Separability conditions are often formulated for measurements that have a special structure. For instance, mutually unbiased bases and mutually unbiased measurements can be utilized for such purposes. Using resolution of the identity for each subsystem of a bipartite system, we construct some resolution of the identity in the product of Hilbert spaces. Separability conditions are then formulated in terms of maximal probabilities for a collection of specific outcomes. The presented conditions are compared with some previous formulations. Our results are exemplified with entangled states of a two-qutrit system.

  17. Separability conditions based on local fine-grained uncertainty relations

    NASA Astrophysics Data System (ADS)

    Rastegin, Alexey E.

    2016-03-01

    Many protocols of quantum information processing use entangled states. Hence, separability criteria are of great importance. We propose new separability conditions for a bipartite finite-dimensional system. They are derived by using fine-grained uncertainty relations. Fine-grained uncertainty relations can be obtained by consideration of the spectral norms of certain positive matrices. One of possible approaches to separability conditions is connected with upper bounds on the sum of maximal probabilities. Separability conditions are often formulated for measurements that have a special structure. For instance, mutually unbiased bases and mutually unbiased measurements can be utilized for such purposes. Using resolution of the identity for each subsystem of a bipartite system, we construct some resolution of the identity in the product of Hilbert spaces. Separability conditions are then formulated in terms of maximal probabilities for a collection of specific outcomes. The presented conditions are compared with some previous formulations. Our results are exemplified with entangled states of a two-qutrit system.

  18. Unbiased Identification of Patients with Disorders of Sex Development

    PubMed Central

    Hanauer, David A.; Gardner, Melissa; Sandberg, David E.

    2014-01-01

    Disorders of sex development (DSD) represent a collection of rare diseases that generate substantial controversy regarding best practices for diagnosis and treatment. A significant barrier preventing a better understanding of how patients with these conditions should be evaluated and treated, especially from a psychological standpoint, is the lack of systematic and standardized approaches to identify cases for study inclusion. Common approaches include “hand-picked” subjects already known to the practice, which could introduce bias. We implemented an informatics-based approach to identify patients with DSD from electronic health records (EHRs) at three large, academic children’s hospitals. The informatics approach involved comprehensively searching EHRs at each hospital using a combination of structured billing codes as an initial filtering strategy followed by keywords applied to the free text clinical documentation. The informatics approach was implemented to replicate the functionality of an EHR search engine (EMERSE) available at one of the hospitals. At the two hospitals that did not have EMERSE, we compared case ascertainment using the informatics method to traditional approaches employed for identifying subjects. Potential cases identified using all approaches were manually reviewed by experts in DSD to verify eligibility criteria. At the two institutions where both the informatics and traditional approaches were applied, the informatics approach identified substantially higher numbers of potential study subjects. The traditional approaches yielded 14 and 28 patients with DSD, respectively; the informatics approach yielded 226 and 77 patients, respectively. The informatics approach missed only a few cases that the traditional approaches identified, largely because those cases were known to the study team, but patient data were not in the particular children’s hospital EHR. The use of informatics approaches to search electronic documentation can

  19. Revisiting AFLP fingerprinting for an unbiased assessment of genetic structure and differentiation of taurine and zebu cattle

    PubMed Central

    2014-01-01

    Background Descendants from the extinct aurochs (Bos primigenius), taurine (Bos taurus) and zebu cattle (Bos indicus) were domesticated 10,000 years ago in Southwestern and Southern Asia, respectively, and colonized the world undergoing complex events of admixture and selection. Molecular data, in particular genome-wide single nucleotide polymorphism (SNP) markers, can complement historic and archaeological records to elucidate these past events. However, SNP ascertainment in cattle has been optimized for taurine breeds, imposing limitations to the study of diversity in zebu cattle. As amplified fragment length polymorphism (AFLP) markers are discovered and genotyped as the samples are assayed, this type of marker is free of ascertainment bias. In order to obtain unbiased assessments of genetic differentiation and structure in taurine and zebu cattle, we analyzed a dataset of 135 AFLP markers in 1,593 samples from 13 zebu and 58 taurine breeds, representing nine continental areas. Results We found a geographical pattern of expected heterozygosity in European taurine breeds decreasing with the distance from the domestication centre, arguing against a large-scale introgression from European or African aurochs. Zebu cattle were found to be at least as diverse as taurine cattle. Western African zebu cattle were found to have diverged more from Indian zebu than South American zebu. Model-based clustering and ancestry informative markers analyses suggested that this is due to taurine introgression. Although a large part of South American zebu cattle also descend from taurine cows, we did not detect significant levels of taurine ancestry in these breeds, probably because of systematic backcrossing with zebu bulls. Furthermore, limited zebu introgression was found in Podolian taurine breeds in Italy. Conclusions The assessment of cattle diversity reported here contributes an unbiased global view to genetic differentiation and structure of taurine and zebu cattle

  20. Exometabolomics Assisted Design and Validation of Synthetic Obligate Mutualism.

    PubMed

    Kosina, Suzanne M; Danielewicz, Megan A; Mohammed, Mujahid; Ray, Jayashree; Suh, Yumi; Yilmaz, Suzan; Singh, Anup K; Arkin, Adam P; Deutschbauer, Adam M; Northen, Trent R

    2016-07-15

    Synthetic microbial ecology has the potential to enhance the productivity and resiliency of biotechnology processes compared to approaches using single isolates. Engineering microbial consortia is challenging; however, one approach that has attracted significant attention is the creation of synthetic obligate mutualism using auxotrophic mutants that depend on each other for exchange or cross-feeding of metabolites. Here, we describe the integration of mutant library fitness profiling with mass spectrometry based exometabolomics as a method for constructing synthetic mutualism based on cross-feeding. Two industrially important species lacking known ecological interactions, Zymomonas mobilis and Escherichia coli, were selected as the test species. Amino acid exometabolites identified in the spent medium of Z. mobilis were used to select three corresponding E. coli auxotrophs (proA, pheA and IlvA), as potential E. coli counterparts for the coculture. A pooled mutant fitness assay with a Z. mobilis transposon mutant library was used to identify mutants with improved growth in the presence of E. coli. An auxotroph mutant in a gene (ZMO0748) with sequence similarity to cysteine synthase A (cysK), was selected as the Z. mobilis counterpart for the coculture. Exometabolomic analysis of spent E. coli medium identified glutathione related metabolites as potentially available for rescue of the Z. mobilis cysteine synthase mutant. Three sets of cocultures between the Z. mobilis auxotroph and each of the three E. coli auxotrophs were monitored by optical density for growth and analyzed by flow cytometry to confirm high cell counts for each species. Taken together, our methods provide a technological framework for creating synthetic mutualisms combining existing screening based methods and exometabolomics for both the selection of obligate mutualism partners and elucidation of metabolites involved in auxotroph rescue. PMID:26885935

  1. Contextual classification of multispectral image data - An unbiased estimator for the context distribution

    NASA Technical Reports Server (NTRS)

    Tilton, J. C.; Swain, P. H.; Vardeman, S. B.

    1981-01-01

    Recent investigations have demonstrated the effectiveness of a contextual classifier that combines spatial and spectral information employing a general statistical approach. This statistical classification algorithm exploits the tendency of certain ground-cover classes to occur more frequently in some spatial contexts than in others. Indeed, a key input to this algorithm is a statistical characterization of the context: the context distribution. Here a discussion is given of an unbiased estimator of the context distribution which, besides having the advantage of statistical unbiasedness, has the additional advantage over other estimation techniques of being amenable to an adaptive implementation in which the context distribution estimate varies according to local contextual information. Results from applying the unbiased estimator to the contextual classification of three real Landsat data sets are presented and contrasted with results from noncontextual classifications and from contextual classifications utilizing other context distribution estimation techniques.

  2. Unbiased reconstruction of a mammalian transcriptional network mediating the differential response to pathogens

    PubMed Central

    Amit, Ido; Garber, Manuel; Chevrier, Nicolas; Leite, Ana Paula; Donner, Yoni; Eisenhaure, Thomas; Guttman, Mitchell; Grenier, Jennifer K.; Li, Weibo; Zuk, Or; Schubert, Lisa A.; Birditt, Brian; Shay, Tal; Goren, Alon; Zhang, Xiaolan; Smith, Zachary; Deering, Raquel; McDonald, Rebecca C.; Cabili, Moran; Bernstein, Bradley E; Rinn, John L.; Meissner, Alex; Root, David E.; Hacohen, Nir; Regev, Aviv

    2010-01-01

    Models of mammalian regulatory networks controlling gene expression have been inferred from genomic data, yet have largely not been validated. We present an unbiased strategy to systematically perturb candidate regulators and monitor cellular transcriptional responses. We apply this approach to derive regulatory networks that control the transcriptional response of mouse primary dendritic cells (DCs) to pathogens. Our approach revealed the regulatory functions of 125 transcription factors, chromatin modifiers, and RNA binding proteins and constructed a network model consisting of two dozen core regulators and 76 fine-tuners that help explain how pathogen-sensing pathways achieve specificity. This study establishes a broadly-applicable, comprehensive and unbiased approach to reveal the wiring and functions of a regulatory network controlling a major transcriptional response in primary mammalian cells. PMID:19729616

  3. 78 FR 64600 - Mutual Savings Association Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... Office of the Comptroller of the Currency Mutual Savings Association Advisory Committee AGENCY... Mutual Savings Association Advisory Committee (MSAAC). DATES: A public meeting of the MSAAC will be held... mutual savings associations and other issues of concern to the existing mutual savings...

  4. 75 FR 77048 - Mutual Savings Association Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ... Office of Thrift Supervision Mutual Savings Association Advisory Committee AGENCY: Department of the... Thrift Supervision has determined that the renewal of the ] Charter of the OTS Mutual Savings Association... facing mutual savings associations. DATES: The Charter of the OTS Mutual Savings Association...

  5. Group Differences in the Mutual Gaze of Chimpanzees (Pan Troglodytes)

    ERIC Educational Resources Information Center

    Bard, Kim A.; Myowa-Yamakoshi, Masako; Tomonaga, Masaki; Tanaka, Masayuki; Costall, Alan; Matsuzawa, Tetsuro

    2005-01-01

    A comparative developmental framework was used to determine whether mutual gaze is unique to humans and, if not, whether common mechanisms support the development of mutual gaze in chimpanzees and humans. Mother-infant chimpanzees engaged in approximately 17 instances of mutual gaze per hour. Mutual gaze occurred in positive, nonagonistic…

  6. 12 CFR 575.3 - Mutual holding company reorganizations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Mutual holding company reorganizations. 575.3 Section 575.3 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY MUTUAL HOLDING COMPANIES § 575.3 Mutual holding company reorganizations. A mutual savings association may reorganize...

  7. 12 CFR 575.3 - Mutual holding company reorganizations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Mutual holding company reorganizations. 575.3 Section 575.3 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY MUTUAL HOLDING COMPANIES § 575.3 Mutual holding company reorganizations. A mutual savings association may reorganize...

  8. 12 CFR 144.1 - Federal mutual charter.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Federal mutual charter. 144.1 Section 144.1 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 144.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  9. 12 CFR 544.1 - Federal mutual charter.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Federal mutual charter. 544.1 Section 544.1 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 544.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  10. 12 CFR 144.1 - Federal mutual charter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Federal mutual charter. 144.1 Section 144.1 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 144.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  11. 12 CFR 544.1 - Federal mutual charter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Federal mutual charter. 544.1 Section 544.1 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Charter § 544.1 Federal mutual charter. A Federal mutual savings association shall have a charter in the following...

  12. 12 CFR 544.5 - Federal mutual savings association bylaws.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Federal mutual savings association bylaws. 544.5 Section 544.5 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FEDERAL MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Bylaws § 544.5 Federal mutual savings association bylaws. (a) General. A Federal mutual...

  13. Monofunctional stealth nanoparticle for unbiased single molecule tracking inside living cells.

    PubMed

    Lisse, Domenik; Richter, Christian P; Drees, Christoph; Birkholz, Oliver; You, Changjiang; Rampazzo, Enrico; Piehler, Jacob

    2014-01-01

    On the basis of a protein cage scaffold, we have systematically explored intracellular application of nanoparticles for single molecule studies and discovered that recognition by the autophagy machinery plays a key role for rapid metabolism in the cytosol. Intracellular stealth nanoparticles were achieved by heavy surface PEGylation. By combination with a generic approach for nanoparticle monofunctionalization, efficient labeling of intracellular proteins with high fidelity was accomplished, allowing unbiased long-term tracking of proteins in the outer mitochondrial membrane. PMID:24655019

  14. Modeling of a bipedal robot using mutually coupled Rayleigh oscillators.

    PubMed

    Filho, Armando C de Pina; Dutra, Max S; Raptopoulos, Luciano S C

    2005-01-01

    The objective of the work presented here was the modeling of a bipedal robot using a central pattern generator (CPG) formed by a set of mutually coupled Rayleigh oscillators. We analyzed a 2D model, with the three most important determinants of gait, that performs only motions parallel to the sagittal plane. Using oscillators with integer relation of frequency, we determined the transient motion and the stable limit cycles of the network formed by the three oscillators, showing the behavior of the knee angles and the hip angle. A comparison of the plotted graphs revealed that the system provided excellent results when compared to experimental analysis. Based on the results of the study, we come to the conclusion that the use of mutually coupled Rayleigh oscillators can represent an excellent method of signal generation, allowing their application for feedback control of a walking machine. PMID:15580522

  15. Integrated semiconductor twin-microdisk laser under mutually optical injection

    SciTech Connect

    Zou, Ling-Xiu; Liu, Bo-Wen; Lv, Xiao-Meng; Yang, Yue-De; Xiao, Jin-Long; Huang, Yong-Zhen

    2015-05-11

    We experimentally study the characteristics of an integrated semiconductor twin-microdisk laser under mutually optical injection through a connected optical waveguide. Based on the lasing spectra, four-wave mixing, injection locking, and period-two oscillation states are observed due to the mutually optical injection by adjusting the injected currents applied to the two microdisks. The enhanced 3 dB bandwidth is realized for the microdisk laser at the injection locking state, and photonic microwave is obtained from the electrode of the microdisk laser under the period-two oscillation state. The plentifully dynamical states similar as semiconductor lasers subject to external optical injection are realized due to strong optical interaction between the two microdisks.

  16. Building unbiased estimators from non-gaussian likelihoods with application to shear estimation

    SciTech Connect

    Madhavacheril, Mathew S.; McDonald, Patrick; Sehgal, Neelima; Slosar, Anze

    2015-01-15

    We develop a general framework for generating estimators of a given quantity which are unbiased to a given order in the difference between the true value of the underlying quantity and the fiducial position in theory space around which we expand the likelihood. We apply this formalism to rederive the optimal quadratic estimator and show how the replacement of the second derivative matrix with the Fisher matrix is a generic way of creating an unbiased estimator (assuming choice of the fiducial model is independent of data). Next we apply the approach to estimation of shear lensing, closely following the work of Bernstein and Armstrong (2014). Our first order estimator reduces to their estimator in the limit of zero shear, but it also naturally allows for the case of non-constant shear and the easy calculation of correlation functions or power spectra using standard methods. Both our first-order estimator and Bernstein and Armstrong’s estimator exhibit a bias which is quadratic in true shear. Our third-order estimator is, at least in the realm of the toy problem of Bernstein and Armstrong, unbiased to 0.1% in relative shear errors Δg/g for shears up to |g| = 0.2.

  17. Building unbiased estimators from non-gaussian likelihoods with application to shear estimation

    DOE PAGESBeta

    Madhavacheril, Mathew S.; McDonald, Patrick; Sehgal, Neelima; Slosar, Anze

    2015-01-15

    We develop a general framework for generating estimators of a given quantity which are unbiased to a given order in the difference between the true value of the underlying quantity and the fiducial position in theory space around which we expand the likelihood. We apply this formalism to rederive the optimal quadratic estimator and show how the replacement of the second derivative matrix with the Fisher matrix is a generic way of creating an unbiased estimator (assuming choice of the fiducial model is independent of data). Next we apply the approach to estimation of shear lensing, closely following the workmore » of Bernstein and Armstrong (2014). Our first order estimator reduces to their estimator in the limit of zero shear, but it also naturally allows for the case of non-constant shear and the easy calculation of correlation functions or power spectra using standard methods. Both our first-order estimator and Bernstein and Armstrong’s estimator exhibit a bias which is quadratic in true shear. Our third-order estimator is, at least in the realm of the toy problem of Bernstein and Armstrong, unbiased to 0.1% in relative shear errors Δg/g for shears up to |g| = 0.2.« less

  18. Building unbiased estimators from non-Gaussian likelihoods with application to shear estimation

    SciTech Connect

    Madhavacheril, Mathew S.; Sehgal, Neelima; McDonald, Patrick; Slosar, Anže E-mail: pvmcdonald@lbl.gov E-mail: anze@bnl.gov

    2015-01-01

    We develop a general framework for generating estimators of a given quantity which are unbiased to a given order in the difference between the true value of the underlying quantity and the fiducial position in theory space around which we expand the likelihood. We apply this formalism to rederive the optimal quadratic estimator and show how the replacement of the second derivative matrix with the Fisher matrix is a generic way of creating an unbiased estimator (assuming choice of the fiducial model is independent of data). Next we apply the approach to estimation of shear lensing, closely following the work of Bernstein and Armstrong (2014). Our first order estimator reduces to their estimator in the limit of zero shear, but it also naturally allows for the case of non-constant shear and the easy calculation of correlation functions or power spectra using standard methods. Both our first-order estimator and Bernstein and Armstrong's estimator exhibit a bias which is quadratic in true shear. Our third-order estimator is, at least in the realm of the toy problem of Bernstein and Armstrong, unbiased to 0.1% in relative shear errors Δg/g for shears up to |g|=0.2.

  19. Mutualisms in a changing world: an evolutionary perspective.

    PubMed

    Toby Kiers, E; Palmer, Todd M; Ives, Anthony R; Bruno, John F; Bronstein, Judith L

    2010-12-01

    Ecology Letters (2010) 13: 1459-1474 ABSTRACT: There is growing concern that rapid environmental degradation threatens mutualistic interactions. Because mutualisms can bind species to a common fate, mutualism breakdown has the potential to expand and accelerate effects of global change on biodiversity loss and ecosystem disruption. The current focus on the ecological dynamics of mutualism under global change has skirted fundamental evolutionary issues. Here, we develop an evolutionary perspective on mutualism breakdown to complement the ecological perspective, by focusing on three processes: (1) shifts from mutualism to antagonism, (2) switches to novel partners and (3) mutualism abandonment. We then identify the evolutionary factors that may make particular classes of mutualisms especially susceptible or resistant to breakdown and discuss how communities harbouring mutualisms may be affected by these evolutionary responses. We propose a template for evolutionary research on mutualism resilience and identify conservation approaches that may help conserve targeted mutualisms in the face of environmental change. PMID:20955506

  20. Track-to-Track Data Association using Mutual Information

    NASA Astrophysics Data System (ADS)

    Hussein, I.; Roscoe, C.; Wilkins, M.; Schumacher, P.

    In this paper, we build on recent work to further investigate the use of mutual information to solve various association problems in space situational awareness. Specifically, we solve the track-to-track association (TTTA) problem where we seek to associate a given set of tracks at one point in time with another set of tracks at a different time instance. Both sets of tracks are uncertain and are probabilistically described using multivariate normal distributions. This allows for a closed-form solution, based on the unscented transform and on mutual information. Future work will focus on developing a similar solution when uncertainty is analytic but not Gaussian or when it is completely non-analytic -e.g., when the uncertainty is described using a particle cloud. The proposed solution is inspired by a similar solution based on the unscented transform and mutual information for the observation-to-observation association (OTOA) problem that was developed by the authors in the past. This solution can be adjusted to address the classical observation-to-track association problem (OTTA), which will be the focus of future research. We will demonstrate the main result in simulation for LEO, MEO, GTO, and GEO orbit regimes to show general applicability.

  1. Integrating plant carbon dynamics with mutualism ecology.

    PubMed

    Pringle, Elizabeth G

    2016-04-01

    71 I. 71 II. 72 III. 73 IV. 74 V. 74 74 References 74 SUMMARY: Plants reward microbial and animal mutualists with carbohydrates to obtain nutrients, defense, pollination, and dispersal. Under a fixed carbon budget, plants must allocate carbon to their mutualists at the expense of allocation to growth, reproduction, or storage. Such carbon trade-offs are indirectly expressed when a plant exhibits reduced growth or fecundity in the presence of its mutualist. Because carbon regulates the costs of all plant mutualisms, carbon dynamics are a common platform for integrating these costs in the face of ecological complexity and context dependence. The ecophysiology of whole-plant carbon allocation could thus elucidate the ecology and evolution of plant mutualisms. If mutualisms are costly to plants, then they must be important but frequently underestimated sinks in the terrestrial carbon cycle. PMID:26414800

  2. Mutual inductance between piecewise-linear loops

    NASA Astrophysics Data System (ADS)

    Cristina Barroso, Ana; Silva, J. P.

    2013-11-01

    We consider a current-carrying wire loop made out of linear segments of arbitrary sizes and directions in three-dimensional space. We develop expressions to calculate its vector potential and magnetic field at all points in space. We then calculate the mutual inductance between two such (non-intersecting) piecewise-linear loops. As simple applications, we consider in detail the mutual inductance between two square wires of equal length that either lie in the same plane or lie in parallel horizontal planes with their centers on the same vertical axis. Our expressions can also be used to obtain approximations to the mutual inductance between wires of arbitrary three-dimensional shapes.

  3. Distribution of Mutual Information in Multipartite States

    NASA Astrophysics Data System (ADS)

    Maziero, Jonas

    2014-06-01

    Using the relative entropy of total correlation, we derive an expression relating the mutual information of n-partite pure states to the sum of the mutual informations and entropies of its marginals and analyze some of its implications. Besides, by utilizing the extended strong subadditivity of von Neumann entropy, we obtain generalized monogamy relations for the total correlation in three-partite mixed states. These inequalities lead to a tight lower bound for this correlation in terms of the sum of the bipartite mutual informations. We use this bound to propose a measure for residual three-partite total correlation and discuss the non-applicability of this kind of quantifier to measure genuine multiparty correlations.

  4. The design of microstrip dipole arrays including mutual coupling. I Theory. II - Experiment

    NASA Astrophysics Data System (ADS)

    Elliott, R. S.; Stern, G. J.

    1981-09-01

    A design technique which includes mutual coupling is formulated for use with microstrip dipole arrays. The technique is based on iterative solution of a combined design equation and requires as input foreknowledge of the self-impedances and mutual impedances of microstrip dipoles and also the link between the radiating current and the backscattered wave in the feeding line. Procedures for obtaining the input design data for microstrip dipole arrays are then described and the design of a typical array is presented. The design data indicate that mutual coupling is a significant factor which cannot be ignored in the design of small microstrip dipole arrays.

  5. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Tax on insurance companies (other than life or... insurance companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual policies. (a) All insurance companies, other than life or mutual...

  6. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Tax on insurance companies (other than life or... insurance companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual policies. (a) All insurance companies, other than life or mutual...

  7. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Tax on insurance companies (other than life or... insurance companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual policies. (a) All insurance companies, other than life or mutual...

  8. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Tax on insurance companies (other than life or... insurance companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual policies. (a) All insurance companies, other than life or mutual...

  9. 26 CFR 1.831-1 - Tax on insurance companies (other than life or mutual), mutual marine insurance companies, and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Tax on insurance companies (other than life or... companies (other than life or mutual), mutual marine insurance companies, and mutual fire insurance companies issuing perpetual policies. (a) All insurance companies, other than life or mutual or...

  10. Conceptual Alignment: How Brains Achieve Mutual Understanding.

    PubMed

    Stolk, Arjen; Verhagen, Lennart; Toni, Ivan

    2016-03-01

    We share our thoughts with other minds, but we do not understand how. Having a common language certainly helps, but infants' and tourists' communicative success clearly illustrates that sharing thoughts does not require signals with a pre-assigned meaning. In fact, human communicators jointly build a fleeting conceptual space in which signals are a means to seek and provide evidence for mutual understanding. Recent work has started to capture the neural mechanisms supporting those fleeting conceptual alignments. The evidence suggests that communicators and addressees achieve mutual understanding by using the same computational procedures, implemented in the same neuronal substrate, and operating over temporal scales independent from the signals' occurrences. PMID:26792458

  11. X-ray Properties of an Unbiased Hard X-ray Detected Sample of AGN

    NASA Technical Reports Server (NTRS)

    Winter, Lisa M.; Mushotzky, Richard F.; Tueller, Jack; Markwardt, Craig

    2007-01-01

    The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a sample of active galactic nuclei (AGN) based solely on their hard X-ray flux (14-195keV). In this paper, we present for the first time XMM-Newton X-ray spectra for 22 BAT AGXs with no previously analyzed X-ray spectra. If our sources are a representative sample of the BAT AGN, as we claim, our results present for the first time global X-ray properties of an unbiased towards absorption (n(sub H) < 3 x 10(exp 25)/sq cm), local (< z >= 0.03), AGN sample. We find 9/22 low absorption (n(sub H) < 10(exp 23)/sq cm), simple power law model sources, where 4 of these sources have a statistically significant soft component. Among these sources, we find the presence of a warm absorber statistically significant for only one Seyfert 1 source, contrasting with the ASCA results of Reynolds (1997) and George et al. (1998), who find signatures of warm absorption in half or more of their Seyfert 1 samples at similar redshifts. Additionally, the remaining sources (13122) have more complex spectra, well-fit by an absorbed power law at E > 2.0 keV. Five of the complex sources (NGC 612, ESO 362-G018, MRK 417, ESO 506-G027, and NGC 6860) are classified as Compton-thick candidates. Further, we find four more sources (SWIFT J0641.3+3257, SWIFT J0911.2+4533, SWIFT J1200.8+0650, and NGC 4992) with properties consistent with the hidden/buried AGN reported by Ueda et al. (2007). Finally, we include a comparison of the XMM EPIC spectra with available SWIFT X-ray Telescope (XRT) observations. From these comparisons, we find 6/16 sources with varying column densities, 6/16 sources with varying power law indices, and 13/16 sources with varying fluxes, over periods of hours to months. Flux and power law index are correlated for objects where both parameters vary.

  12. Unbiased Estimate of Dark Energy Density from Type Ia Supernova Data

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Lovelace, Geoffrey

    2001-12-01

    Type Ia supernovae (SNe Ia) are currently the best probes of the dark energy in the universe. To constrain the nature of dark energy, we assume a flat universe and that the weak energy condition is satisfied, and we allow the density of dark energy, ρX(z), to be an arbitrary function of redshift. Using simulated data from a space-based SN pencil-beam survey, we find that by optimizing the number of parameters used to parameterize the dimensionless dark energy density, f(z)=ρX(z)/ρX(z=0), we can obtain an unbiased estimate of both f(z) and the fractional matter density of the universe, Ωm. A plausible SN pencil-beam survey (with a square degree field of view and for an observational duration of 1 yr) can yield about 2000 SNe Ia with 0<=z<=2. Such a survey in space would yield SN peak luminosities with a combined intrinsic and observational dispersion of σ(mint)=0.16 mag. We find that for such an idealized survey, Ωm can be measured to 10% accuracy, and the dark energy density can be estimated to ~20% to z~1.5, and ~20%-40% to z~2, depending on the time dependence of the true dark energy density. Dark energy densities that vary more slowly can be more accurately measured. For the anticipated Supernova/Acceleration Probe (SNAP) mission, Ωm can be measured to 14% accuracy, and the dark energy density can be estimated to ~20% to z~1.2. Our results suggest that SNAP may gain much sensitivity to the time dependence of the dark energy density and Ωm by devoting more observational time to the central pencil-beam fields to obtain more SNe Ia at z>1.2. We use both a maximum likelihood analysis and a Monte Carlo analysis (when appropriate) to determine the errors of estimated parameters. We find that the Monte Carlo analysis gives a more accurate estimate of the dark energy density than the maximum likelihood analysis.

  13. Probing the effects of external irradiation on low-mass protostars through unbiased line surveys

    NASA Astrophysics Data System (ADS)

    Lindberg, J. E.; Jørgensen, J. K.; Watanabe, Y.; Bisschop, S. E.; Sakai, N.; Yamamoto, S.

    2015-12-01

    Context. The envelopes of molecular gas around embedded low-mass protostars show different chemistries, which can be used to trace their formation history and physical conditions. The excitation conditions of some molecular species can also be used to trace these physical conditions, making it possible to constrain for instance sources of heating and excitation. Aims: We study the range of influence of an intermediate-mass Herbig Be protostar. We also study the effect of feedback from the environment on the chemical and physical properties of embedded protostars. Methods: We followed up on an earlier line survey of the Class 0/I source R CrA IRS7B in the 0.8 mm window with an unbiased line survey of the same source in the 1.3 mm window using the Atacama Pathfinder Experiment (APEX) telescope. We also studied the excitation of the key species H2CO, CH3OH, and c-C3H2 in a complete sample of the 18 embedded protostars in the Corona Australis star-forming region. Radiative transfer models were employed to establish abundances of the molecular species. Results: We detect line emission from 20 molecular species (32 including isotopologues) in the two surveys. The most complex species detected are CH3OH, CH3CCH, CH3CHO, and CH3CN (the latter two are only tentatively detected). CH3CN and several other complex organic molecules are significantly under-abundant in comparison with what is found towards hot corino protostars. The H2CO rotational temperatures of the sources in the region decrease with the distance to the Herbig Be star R CrA, whereas the c-C3H2 temperatures remain constant across the star-forming region. Conclusions: The high H2CO temperatures observed towards objects close to R CrA suggest that this star has a sphere of influence of several 10 000 AU in which it increases the temperature of the molecular gas to 30-50 K through irradiation. The chemistry in the IRS7B envelope differs significantly from many other embedded protostars, which could be an effect of

  14. A consumer-resource approach to the density-dependent population dynamics of mutualism

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2010-01-01

    Like predation and competition, mutualism is now recognized as a consumer resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant- mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

  15. An unbiased longitudinal analysis framework for tracking white matter changes using diffusion tensor imaging with application to Alzheimer's disease.

    PubMed

    Keihaninejad, Shiva; Zhang, Hui; Ryan, Natalie S; Malone, Ian B; Modat, Marc; Cardoso, M Jorge; Cash, David M; Fox, Nick C; Ourselin, Sebastien

    2013-05-15

    We introduce a novel image-processing framework for tracking longitudinal changes in white matter microstructure using diffusion tensor imaging (DTI). Charting the trajectory of such temporal changes offers new insight into disease progression but to do so accurately faces a number of challenges. Recent developments have highlighted the importance of processing each subject's data at multiple time points in an unbiased way. In this paper, we aim to highlight a different challenge critical to the processing of longitudinal DTI data, namely the approach to image alignment. Standard approaches in the literature align DTI data by registering the corresponding scalar-valued fractional anisotropy (FA) maps. We propose instead a DTI registration algorithm that leverages full tensor information to drive improved alignment. This proposed pipeline is evaluated against the standard FA-based approach using a DTI dataset from an ongoing study of Alzheimer's disease (AD). The dataset consists of subjects scanned at two time points and at each time point the DTI acquisition consists of two back-to-back repeats in the same scanning session. The repeated scans allow us to evaluate the specificity of each pipeline, using a test-retest design, and assess precision, using bootstrap-based method. The results show that the tensor-based pipeline achieves both higher specificity and precision than the standard FA-based approach. Tensor-based registration for longitudinal processing of DTI data in clinical studies may be of particular value in studies assessing disease progression. PMID:23370057

  16. Part mutual information for quantifying direct associations in networks.

    PubMed

    Zhao, Juan; Zhou, Yiwei; Zhang, Xiujun; Chen, Luonan

    2016-05-01

    Quantitatively identifying direct dependencies between variables is an important task in data analysis, in particular for reconstructing various types of networks and causal relations in science and engineering. One of the most widely used criteria is partial correlation, but it can only measure linearly direct association and miss nonlinear associations. However, based on conditional independence, conditional mutual information (CMI) is able to quantify nonlinearly direct relationships among variables from the observed data, superior to linear measures, but suffers from a serious problem of underestimation, in particular for those variables with tight associations in a network, which severely limits its applications. In this work, we propose a new concept, "partial independence," with a new measure, "part mutual information" (PMI), which not only can overcome the problem of CMI but also retains the quantification properties of both mutual information (MI) and CMI. Specifically, we first defined PMI to measure nonlinearly direct dependencies between variables and then derived its relations with MI and CMI. Finally, we used a number of simulated data as benchmark examples to numerically demonstrate PMI features and further real gene expression data from Escherichia coli and yeast to reconstruct gene regulatory networks, which all validated the advantages of PMI for accurately quantifying nonlinearly direct associations in networks. PMID:27092000

  17. Variation between self- and mutual assessment in animal contests.

    PubMed

    Mesterton-Gibbons, Mike; Heap, Stephen M

    2014-02-01

    Limited resources lead animals into conflicts of interest, which are resolved when an individual withdraws from a direct contest. Current theory suggests that the decision to withdraw can be based on a threshold derived from an individual's own state (self-assessment) or on a comparison between their own state and their opponent's (mutual assessment). The observed variation between these assessment strategies in nature does not conform to theory. Thus, we require theoretical developments that explain the functional significance of different assessment strategies. We consider a hawk-dove game with two discrete classes that differ in fighting ability, in which the players strategically decide on their investment toward mutual assessment. Analysis of the model indicates that there are simultaneous trade-offs relating to assessment strategies. First, weak individuals in a population must decide on whether to acquire information about their opponents at the cost of providing opponents with information about themselves. Secondly, all individuals must decide between investing in mutual assessment and being persistent in contests. Our analysis suggests that the potential for individuals to make errors during contests and differences in the consequences of sharing information within a population may serve as fundamental concepts for explaining variation in assessment strategy. PMID:24464195

  18. Generalized approach for using unbiased symmetric metrics with negative values: normalized mean bias factor and normalized mean absolute error factor

    EPA Science Inventory

    Unbiased symmetric metrics provide a useful measure to quickly compare two datasets, with similar interpretations for both under and overestimations. Two examples include the normalized mean bias factor and normalized mean absolute error factor. However, the original formulations...

  19. 76 FR 36625 - Mutual Holding Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... Office of Thrift Supervision Mutual Holding Company AGENCY: Office of Thrift Supervision (OTS), Treasury... Thrift Supervision, 1700 G Street, NW., Washington, DC 20552, by fax to (202) 906-6518, or by e-mail to...'s Office, Office of Thrift Supervision, 1700 G Street, NW., Washington, DC 20552....

  20. Mutual diffusion in a binary isotopic mixture.

    PubMed

    Sharma, Raman; Tankeshwar, K

    2010-11-17

    The mass dependence of the mutual diffusion coefficient, in a binary equimolar mixture of Lennard-Jones fluids, is studied within Mori's memory function formalism. A phenomenological form of the memory function is used to study the time evolution of the self- and relative velocity correlation functions. The diffusion coefficients are calculated from the relevant velocity correlation functions using the Green-Kubo integral formula. Like the self-diffusion coefficient, the mutual diffusion coefficient is also found to be weakly dependent on the mass ratio. The present study shows that the minimum value that the mutual diffusion coefficient in an equimolar mixture of isotopic fluids can have is √(1/2) times the self-diffusion coefficient of any of the species when in isolation. Further, the contribution of the dynamic/distinct cross correlations to the mutual diffusion coefficient is found to be small and positive for the whole range of the mass ratio which is consistent with earlier molecular dynamics results. PMID:21339621

  1. Mutual diffusion of interacting membrane proteins.

    PubMed Central

    Abney, J R; Scalettar, B A; Owicki, J C

    1989-01-01

    The generalized Stokes-Einstein equation is used, together with the two-dimensional pressure equation, to analyze mutual diffusion in concentrated membrane systems. These equations can be used to investigate the role that both direct and hydrodynamic interactions play in determining diffusive behavior. Here only direct interactions are explicitly incorporated into the theory at high densities; however, both direct and hydrodynamic interactions are analyzed for some dilute solutions. We look at diffusion in the presence of weak attractions, soft repulsions, and hard-core repulsions. It is found that, at low densities, attractions retard mutual diffusion while repulsions enhance it. Mechanistically, attractions tend to tether particles together and oppose the dissipation of gradients or fluctuations in concentration, while repulsions provide a driving force that pushes particles apart. At higher concentrations, changes in the structure of the fluid enhance mutual diffusion even in the presence of attractions. It is shown that the theoretical description of postelectrophoresis relaxation and fluorescence correlation spectroscopy experiments must be modified if interacting systems are studied. The effects of interactions on mutual diffusion coefficients have probably already been seen in postelectrophoresis relaxation experiments. PMID:2775829

  2. Mutual Group Hypnosis: A Social Interaction Analysis.

    ERIC Educational Resources Information Center

    Sanders, Shirley

    Mutual Group Hypnosis is discussed in terms of its similarity to group dynamics in general and in terms of its similarity to a social interaction program (Role Modeling) designed to foster the expression of warmth and acceptance among group members. Hypnosis also fosters a regression to prelogical thought processes in the service of the ego. Group…

  3. An investigation of algebraic quantum dynamics for mesoscopic coupled electric circuits with mutual inductance

    NASA Astrophysics Data System (ADS)

    Pahlavani, H.; Kolur, E. Rahmanpour

    2016-08-01

    Based on the electrical charge discreteness, the Hamiltonian operator for the mutual inductance coupled quantum mesoscopic LC circuits has been found. The persistent current on two driven coupled mesoscopic electric pure L circuits (two quantum loops) has been obtained by using algebraic quantum dynamic approach. The influence of the mutual inductance on energy spectrum and quantum fluctuations of the charge and current for two coupled quantum electric mesoscopic LC circuits have been investigated.

  4. Dense registration of CHRIS-Proba and Ikonos images using multi-dimensional mutual information maximization

    NASA Astrophysics Data System (ADS)

    Cariou, Claude; Chehdi, Kacem

    2013-10-01

    We investigate the potential of multidimensional mutual information for the registration of multi-spectral remote sensing images. We devise a gradient flow algorithm which iteratively maximizes the multidimensional mutual information with respect to a differentiable displacement map, accounting for partial derivatives of the multivariate joint distribution and the multivariate marginal of the float image with respect to each variable of the mutual information derivative. The resulting terms are shown to weight the band specific gradients of the warp image, and we propose in addition to compute them with a method based on the k-nearest neighbours. We apply our method to the registration of Ikonos and CHRIS-Proba images over the region of Baabdat, Lebanon, for purposes of cedar pines detection. A comparison between (crossed) single band and multi-band registration results obtained shows that using the multidimensional mutual information brings a significant gain in positional accuracy and is suitable for multispectral remote sensing image registration.

  5. Group transformations and entangled-state quantum gates with directionally unbiased linear-optical multiports

    NASA Astrophysics Data System (ADS)

    Simon, David S.; Fitzpatrick, Casey A.; Sergienko, Alexander V.

    2016-04-01

    The concept of directionally unbiased optical multiports is introduced, in which photons may reflect back out the input direction. A linear-optical implementation is described, and the simplest three-port version studied. Symmetry arguments demonstrate potential for unusual quantum information processing applications. The devices impose group structures on two-photon entangled Bell states and act as universal Bell-state processors to implement probabilistic quantum gates acting on state symmetries. These multiports allow optical scattering experiments to be carried out on arbitrary undirected graphs via linear optics and raise the possibility of linear-optical information processing using group structures formed by optical qudit states.

  6. Estimating unbiased horizontal velocity components from ST/MST radar measurements: A case study

    NASA Technical Reports Server (NTRS)

    Clark, W. L.; Green, J. L.; Warnock, J. M.

    1983-01-01

    In this paper a self-editing quick look procedure is presented for use at the Sunset radar. It is used for determining relatively unbiased hourly estimates of the u and v components of the wind. The technique presented here should be applicable to all height ranges, though only ST results are presented here. The vertical wind component, w, may be measured directly by pointing the radar beam straight up. The east and west components of the wind, u and v, however, must be estimated by projecting to the horizontal plane the radial velocity, vr, actually observed by pointing the radar suitably off zenith.

  7. X-ray and Optical Properties of an Unbiased Sample of Local AGN

    NASA Astrophysics Data System (ADS)

    Winter, Lisa M.; Mushotzky, R.; Tueller, J.; Lewis, K.; Reynolds, C.

    2007-12-01

    The SWIFT Burst Alert Telescope (BAT), while not focused on a Gamma-ray burst, conducts an all-sky survey in the 14 - 195 keV band. After the first 9 months, the BAT has detected a sample of 153 local (z ˜ 0.03) AGN at a flux limit of a few times 10-11 erg/s/cm-2 (Tueller et al. 2007). Since the AGN were detected at very high X-ray energies, they are an unbiased sample towards column densities below 1025 cm-2. We present the X-ray and optical properties of a sample of the BAT AGN.

  8. Hardware device binding and mutual authentication

    SciTech Connect

    Hamlet, Jason R; Pierson, Lyndon G

    2014-03-04

    Detection and deterrence of device tampering and subversion by substitution may be achieved by including a cryptographic unit within a computing device for binding multiple hardware devices and mutually authenticating the devices. The cryptographic unit includes a physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a binding PUF value. The cryptographic unit uses the binding PUF value during an enrollment phase and subsequent authentication phases. During a subsequent authentication phase, the cryptographic unit uses the binding PUF values of the multiple hardware devices to generate a challenge to send to the other device, and to verify a challenge received from the other device to mutually authenticate the hardware devices.

  9. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  10. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  11. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  12. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  13. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and Authorizations Special Rules Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed...

  14. Experimental Strategies for Functional Annotation and Metabolism Discovery: Targeted Screening of Solute Binding Proteins and Unbiased Panning of Metabolomes

    PubMed Central

    2015-01-01

    The rate at which genome sequencing data is accruing demands enhanced methods for functional annotation and metabolism discovery. Solute binding proteins (SBPs) facilitate the transport of the first reactant in a metabolic pathway, thereby constraining the regions of chemical space and the chemistries that must be considered for pathway reconstruction. We describe high-throughput protein production and differential scanning fluorimetry platforms, which enabled the screening of 158 SBPs against a 189 component library specifically tailored for this class of proteins. Like all screening efforts, this approach is limited by the practical constraints imposed by construction of the library, i.e., we can study only those metabolites that are known to exist and which can be made in sufficient quantities for experimentation. To move beyond these inherent limitations, we illustrate the promise of crystallographic- and mass spectrometric-based approaches for the unbiased use of entire metabolomes as screening libraries. Together, our approaches identified 40 new SBP ligands, generated experiment-based annotations for 2084 SBPs in 71 isofunctional clusters, and defined numerous metabolic pathways, including novel catabolic pathways for the utilization of ethanolamine as sole nitrogen source and the use of d-Ala-d-Ala as sole carbon source. These efforts begin to define an integrated strategy for realizing the full value of amassing genome sequence data. PMID:25540822

  15. Mutual synchronization of weakly coupled gyrotrons

    SciTech Connect

    Rozental, R. M.; Glyavin, M. Yu.; Sergeev, A. S.; Zotova, I. V.; Ginzburg, N. S.

    2015-09-15

    The processes of synchronization of two weakly coupled gyrotrons are studied within the framework of non-stationary equations with non-fixed longitudinal field structure. With the allowance for a small difference of the free oscillation frequencies of the gyrotrons, we found a certain range of parameters where mutual synchronization is possible while a high electronic efficiency is remained. It is also shown that synchronization regimes can be realized even under random fluctuations of the parameters of the electron beams.

  16. Combating isolation: Building mutual mentoring networks

    NASA Astrophysics Data System (ADS)

    Cox, Anne J.

    2015-12-01

    Women physicists can often feel isolated at work. Support from a grant through the ADVANCE program of the National Science Foundation (U.S. government funding) created mutual mentoring networks aimed at combating isolation specifically for women faculty at undergraduate-only institutions. This paper will discuss the organization of one such network, what contributed to its success, some of the outcomes, and how it might be implemented in other contexts.

  17. Link Prediction in Complex Networks: A Mutual Information Perspective

    PubMed Central

    Tan, Fei; Xia, Yongxiang; Zhu, Boyao

    2014-01-01

    Topological properties of networks are widely applied to study the link-prediction problem recently. Common Neighbors, for example, is a natural yet efficient framework. Many variants of Common Neighbors have been thus proposed to further boost the discriminative resolution of candidate links. In this paper, we reexamine the role of network topology in predicting missing links from the perspective of information theory, and present a practical approach based on the mutual information of network structures. It not only can improve the prediction accuracy substantially, but also experiences reasonable computing complexity. PMID:25207920

  18. Observations of Pluto-Charon mutual events

    SciTech Connect

    Blanco, C.; Di Martino, M.; Ferreri, W.; Osservatorio Astronomico, Turin )

    1989-07-01

    As part of the planned 'Pluto-Charon Mutual Eclipse Season Campaign', one mutual event was observed at the ESO Observatory on July 10, 1986 and seven mutual events were observed at the Serra La Nave stellar station of Catania Astrophysical Observatory from April 29 to July 21, 1987. At ESO the measurements were performed at the 61-cm Bochum telescope equipped with a photon-counting system and U, B, V, filters; at Serra La Nave the Cassegrain focus of the 91-cm reflector was equipped with a photon-counting system and B and V filters. The observed light losses and contact times do not show relevant systematic deviations from the predicted ones. An examination of the behavior of the B and V light curves gives slight indications of a different slope of the B and V light loss of the same event for a superior or an inferior event, and shows that the superior events are shallower at wavelengths longer than B. 6 refs.

  19. Unbiased query-by-bagging active learning for VHR image classification

    NASA Astrophysics Data System (ADS)

    Copa, Loris; Tuia, Devis; Volpi, Michele; Kanevski, Mikhail

    2010-10-01

    A key factor for the success of supervised remote sensing image classification is the definition of an efficient training set. Suboptimality in the selection of the training samples can bring to low classification performance. Active learning algorithms aim at building the training set in a smart and efficient way, by finding the most relevant samples for model improvement and thus iteratively improving the classification performance. In uncertaintybased approaches, a user-defined heuristic ranks the unlabeled samples according to the classifier's uncertainty about their class membership. Finally, the user is asked to define the labels of the pixels scoring maximum uncertainty. In the present work, an unbiased uncertainty scoring function encouraging sampling diversity is investigated. A modified version of the Entropy Query by Bagging (EQB) approach is presented and tested on very high resolution imagery using both SVM and LDA classifiers. Advantages of favoring diversity in the heuristics are discussed. By the diverse sampling it enhances, the unbiased approach proposed leads to higher convergence rates in the first iterations for both the models considered.

  20. Unbiased constraints on the clumpiness of the Universe from standard candles

    NASA Astrophysics Data System (ADS)

    Li, Zhengxiang; Ding, Xuheng; Zhu, Zong-Hong

    2015-04-01

    We perform unbiased tests for the clumpiness of the Universe by confronting the Zel'dovich-Kantowski-Dyer-Roeder luminosity distance, which describes the effect of local inhomogeneities on the propagation of light with the observational one estimated from measurements of standard candles, i.e., type Ia supernovae (SNe Ia) and gamma-ray bursts (GRBs). Methodologically, we first determine the light-curve fitting parameters which account for distance estimation in SNe Ia observations and the luminosity/energy relations which are responsible for distance estimation of GRBs in the global fit to reconstruct the Hubble diagrams in the context of a clumpy Universe. Subsequently, these Hubble diagrams allow us to achieve unbiased constraints on the matter density parameter Ωm , as well as the clumpiness parameter η which quantifies the fraction of homogeneously distributed matter within a given light cone. At a 1 σ confidence level, the constraints are Ωm=0.34 ±0.02 and η =1.0 0-0.02+0.00 from the joint analysis. The results suggest that the Universe full of Friedman-Lemaître-Robertson-Walker fluid is favored by observations of standard candles with very high statistical significance. On the other hand, they may also indicate that the Zel'dovich-Kantowski-Dyer-Roeder approximation is a sufficiently accurate form to describe the effects of local homogeneity on the expanding Universe.

  1. Magnetic stromal layers for enhanced and unbiased recovery of co-cultured hematopoietic cells.

    PubMed

    Savvateeva, Maria V; Demin, Alexander M; Krasnov, Victor P; Belyavsky, Alexander V

    2016-09-15

    Cell co-culture systems have a long history of application in hematology and hold promise for successful hematopoietic stem and progenitor cell expansion. Here we report that various types of stromal cells used in such co-cultures can be rapidly and efficiently labeled with l-lysine-modified Fe3O4 magnetic nanoparticles. Hematopoiesis-supporting activity does not seem to be compromised after magnetic labeling of stromal cells, and the loss of the label by stromal layers during extended culturing is negligible. Magnetic labeling allows for simple and efficient removal of stromal component, yielding unbiased hematopoietic cell populations. When Lin(-) bone mouse marrow fraction was co-cultured with magnetic stromal layers and resulting cell populations were harvested by trypsinization, the yields of total nucleated cells, colony forming cells, and phenotypically primitive Lin(-)Sca-1(+)c-kit(+) subset were substantially higher as compared with nonadherent cell fractions harvested after conventional stromal co-culture. The advantage offered by the magnetic stroma approach over the traditional one was even more significant after a second round of co-culture and was more dramatic for more primitive hematopoietic cells. We conclude that magnetic stromal layers represent a simple, efficient, and convenient tool for co-culturing and subsequent recovery of sufficiently pure unbiased populations of hematopoietic cells. PMID:27318238

  2. Weighted skewness and kurtosis unbiased by sample size and Gaussian uncertainties

    NASA Astrophysics Data System (ADS)

    Rimoldini, Lorenzo

    2014-07-01

    Central moments and cumulants are often employed to characterize the distribution of data. The skewness and kurtosis are particularly useful for the detection of outliers, the assessment of departures from normally distributed data, automated classification techniques and other applications. Estimators of higher order moments that are robust against outliers are more stable but might miss characteristic features of the data, as in the case of astronomical time series exhibiting brief events like stellar bursts or eclipses of binary systems, while weighting can help identify reliable measurements from uncertain or spurious outliers. Furthermore, noise is an unavoidable part of most measurements and their uncertainties need to be taken properly into account during the data analysis or biases are likely to emerge in the results, including basic descriptive statistics. This work provides unbiased estimates of the weighted skewness and kurtosis moments and cumulants, corrected for biases due to sample size and Gaussian noise, under the assumption of independent data. A comparison of biased and unbiased weighted estimators is illustrated with simulations as a function of sample size and signal-to-noise ratio, employing different data distributions and weighting schemes related to measurement uncertainties and the sampling of the signal. Detailed derivations and figures of simulation results are presented in the Appendices available online.

  3. Estimating unbiased economies of scale of HIV prevention projects: a case study of Avahan.

    PubMed

    Lépine, Aurélia; Vassall, Anna; Chandrashekar, Sudha; Blanc, Elodie; Le Nestour, Alexis

    2015-04-01

    Governments and donors are investing considerable resources on HIV prevention in order to scale up these services rapidly. Given the current economic climate, providers of HIV prevention services increasingly need to demonstrate that these investments offer good 'value for money'. One of the primary routes to achieve efficiency is to take advantage of economies of scale (a reduction in the average cost of a health service as provision scales-up), yet empirical evidence on economies of scale is scarce. Methodologically, the estimation of economies of scale is hampered by several statistical issues preventing causal inference and thus making the estimation of economies of scale complex. In order to estimate unbiased economies of scale when scaling up HIV prevention services, we apply our analysis to one of the few HIV prevention programmes globally delivered at a large scale: the Indian Avahan initiative. We costed the project by collecting data from the 138 Avahan NGOs and the supporting partners in the first four years of its scale-up, between 2004 and 2007. We develop a parsimonious empirical model and apply a system Generalized Method of Moments (GMM) and fixed-effects Instrumental Variable (IV) estimators to estimate unbiased economies of scale. At the programme level, we find that, after controlling for the endogeneity of scale, the scale-up of Avahan has generated high economies of scale. Our findings suggest that average cost reductions per person reached are achievable when scaling-up HIV prevention in low and middle income countries. PMID:25779621

  4. Unbiased high-throughput characterization of mussel transcriptomic responses to sublethal concentrations of the biotoxin okadaic acid

    PubMed Central

    Suarez-Ulloa, Victoria; Fernandez-Tajes, Juan; Aguiar-Pulido, Vanessa; Prego-Faraldo, M. Veronica; Florez-Barros, Fernanda; Sexto-Iglesias, Alexia; Mendez, Josefina

    2015-01-01

    Background. Harmful Algal Blooms (HABs) responsible for Diarrhetic Shellfish Poisoning (DSP) represent a major threat for human consumers of shellfish. The biotoxin Okadaic Acid (OA), a well-known phosphatase inhibitor and tumor promoter, is the primary cause of acute DSP intoxications. Although several studies have described the molecular effects of high OA concentrations on sentinel organisms (e.g., bivalve molluscs), the effect of prolonged exposures to low (sublethal) OA concentrations is still unknown. In order to fill this gap, this work combines Next-Generation sequencing and custom-made microarray technologies to develop an unbiased characterization of the transcriptomic response of mussels during early stages of a DSP bloom. Methods. Mussel specimens were exposed to a HAB episode simulating an early stage DSP bloom (200 cells/L of the dinoflagellate Prorocentrum lima for 24 h). The unbiased characterization of the transcriptomic responses triggered by OA was carried out using two complementary methods of cDNA library preparation: normalized and Suppression Subtractive Hybridization (SSH). Libraries were sequenced and read datasets were mapped to Gene Ontology and KEGG databases. A custom-made oligonucleotide microarray was developed based on these data, completing the expression analysis of digestive gland and gill tissues. Results. Our findings show that exposure to sublethal concentrations of OA is enough to induce gene expression modifications in the mussel Mytilus. Transcriptomic analyses revealed an increase in proteasomal activity, molecular transport, cell cycle regulation, energy production and immune activity in mussels. Oppositely, a number of transcripts hypothesized to be responsive to OA (notably the Serine/Threonine phosphatases PP1 and PP2A) failed to show substantial modifications. Both digestive gland and gill tissues responded similarly to OA, although expression modifications were more dramatic in the former, supporting the choice of

  5. 78 FR 26424 - Mutual Savings Association Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... Office of the Comptroller of the Currency Mutual Savings Association Advisory Committee AGENCY: Office of... Mutual Savings Association Advisory Committee (MSAAC). DATES: A public meeting of the MSAAC will be held... savings associations, and other issues of concern to the existing mutual savings associations. On the...

  6. 77 FR 74052 - Mutual Savings Association Advisory Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... Office of the Comptroller of the Currency Mutual Savings Association Advisory Committee Meeting AGENCY... Mutual Savings Association Advisory Committee (MSAAC or Committee). DATES: A public meeting of the MSAAC... 8:30 a.m. EST. Agenda items include a discussion of the status of the mutual savings...

  7. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 12 2012-04-01 2012-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  8. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 12 2014-04-01 2014-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  9. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 12 2013-04-01 2013-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  10. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in...

  11. 26 CFR 1.1502-42 - Mutual savings banks, etc.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 12 2010-04-01 2010-04-01 false Mutual savings banks, etc. 1.1502-42 Section 1... (CONTINUED) INCOME TAXES Special Taxes and Taxpayers § 1.1502-42 Mutual savings banks, etc. (a) In general. This section applies to mutual s avings banks and other institutions described in section 593(a)....

  12. Measuring unbiased metatranscriptomics in suboxic waters of the central Baltic Sea using a new in situ fixation system

    PubMed Central

    Feike, Janie; Jürgens, Klaus; Hollibaugh, James T; Krüger, Siegfried; Jost, Günter; Labrenz, Matthias

    2012-01-01

    An analysis of the microbial metabolism is fundamental to understanding globally important element transformations. One culture-independent approach to deduce those prokaryotic metabolic functions is to analyze metatranscriptomes. Unfortunately, since mRNA is extremely labile, it is unclear whether the abundance patterns detected in nature are vulnerable to considerable modification in situ simply due to sampling procedures. Exemplified on comparisons of metatranscriptomes retrieved from pelagic suboxic zones of the central Baltic Sea (70–120 m depth), earlier identified as areas of high aerobic ammonium oxidation activity, and quantification of specific transcripts in them, we show that different sampling techniques significantly influence the relative abundance of transcripts presumably diagnostic of the habitat. In situ fixation using our newly developed automatic flow injection sampler resulted in an abundance of thaumarchaeal ammonia monooxygenase transcripts that was up to 30-fold higher than that detected in samples obtained using standard oceanographic sampling systems. By contrast, the abundance of transcripts indicative of cellular stress was significantly greater in non-fixed samples. Thus, the importance of in situ fixation in the reliable evaluation of distinct microbial activities in the ecosystem based on metatranscriptomics is obvious. In consequence, our data indicate that the significance of thaumarchaeota to aerobic ammonium oxidation could yet have been considerably underestimated. Taken these results, this could in general also be the case in attempts aimed at an unbiased gene expression analysis of areas below the epipelagic zone, which cover 90% of the world's oceans. PMID:21776032

  13. Partner selection in the mycorrhizal mutualism.

    PubMed

    Werner, Gijsbert D A; Kiers, E Toby

    2015-03-01

    Partner selection in the mycorrhizal symbiosis is thought to be a key factor stabilising the mutualism. Both plant hosts and mycorrhizal fungi have been shown to preferentially allocate resources to higher quality partners. This can help maintain underground cooperation, although it is likely that different plant species vary in the spatial precision with which they can select partners. Partner selection in the mycorrhizal symbiosis is presumably context-dependent and can be mediated by factors like (relative) resource abundance and resource fluctuations, competition among mycorrhizas, arrival order and cultivation history. Such factors complicate our current understanding of the importance of partner selection and its effectiveness in stimulating mutualistic cooperation. PMID:25421912

  14. An unbiased X-ray sampling of stars within 25 parsecs of the Sun

    NASA Technical Reports Server (NTRS)

    Johnson, H. M.

    1985-01-01

    A search of all of the Einstein Observatory IPC and HRI fields for untargeted stars in the Woolley, et al., Catalogue of the nearby stars is reported. Optical data and IPC coordinates, flux density F sub x, and luminosity L sub x, or upper limits, are tabulated for 126 single or blended systems, and HRI results for a few of them. IPC luminosity functions are derived for the systems, for 193 individual stars in the systems (with L sub x shared equally among blended components), and for 63 individual M dwarfs. These stars have relatively large X-ray flux densities that are free of interstellar extinction, because they are nearby, but they are otherwise unbiased with respect to the X-ray properties that are found in a defined small space around the Sun.

  15. A Serendipitous, Unbiased Survey of Dying Stars in the Kepler Field

    NASA Astrophysics Data System (ADS)

    Kraemer, Kathleen

    We propose to use the Full Field Images (FFIs) from the 4-year Kepler mission, complemented by 2MASS, WISE, and Spitzer, to conduct the first accurate, unbiased census of long-period variables (LPVs) in the Galactic Disk. A fundamental question in stellar astrophysics is how stars shed the bulk of their mass as they die. Much of this mass is ejected during the LPV phase of stellar evolution. That material, enriched by the nucleosynthetic products created deep in a star's interior, is recycled into the interstellar medium (ISM) to form the next generations of stars and planets and, over time, changes the chemical composition of the Galaxy. The amplitude and period distribution of LPVs, and how long they remain in this stage, profoundly impact the type and amount of enriched material that is returned to the ISM. However, a profound impediment to our understanding of this important phase of stellar evolution is the lack of an unbiased sample for the Disk of the Milky Way. Recent variability surveys of the Magellanic Clouds and the Galactic Bulge have accurately counted LPVs in those environments as a function of luminosity, pulsation mode, and period - but no suitable comparison exists for the Galactic Disk. Current counts of Galactic LPVs are from heterogeneous compilations of countless observing programs, each with its own biases. Consequently, the impact of these populations of evolved stars on their host galaxies at solar metallicities remains unknown. Our project will use the FFIs from the Kepler archive to address this need by creating the first unbiased catalog of Disk LPVs and analyzing their properties. These images of the entire 116 square-degree field, taken at a cadence of about once every 30 days, make it possible for the first time to create an unbiased database of pulsating, dying stars on the asymptotic giant branch in the Disk. We will create an atlas of 1500+ day light curves to characterize their variability and mass-loss properties and to enable

  16. Genetic evaluation by best linear unbiased prediction using marker and trait information in a multibreed population.

    PubMed Central

    Wang, T; Fernando, R L; Grossman, M

    1998-01-01

    Genetic evaluation by best linear unbiased prediction (BLUP) requires modeling genetic means, variances, and covariances. This paper presents theory to model means, variances, and covariances in a multibreed population, given marker and breed information, in the presence of gametic disequilibrium between the marker locus (ML) and linked quantitative trait locus (MQTL). Theory and algorithms are presented to construct the matrix of conditional covariances between relatives (Gv) for the MQTL effects in a multibreed population and to obtain the inverse of Gv efficiently. Theory presented here accounts for heterogeneity of variances among pure breeds and for segregation variances between pure breeds. A numerical example was used to illustrate how the theory and algorithms can be used for genetic evaluation by BLUP using marker and trait information in a multibreed population. PMID:9475759

  17. Unbiased phosphoproteomic method identifies the initial effects of a methacrylic acid copolymer on macrophages.

    PubMed

    Chamberlain, Michael Dean; Wells, Laura A; Lisovsky, Alexandra; Guo, Hongbo; Isserlin, Ruth; Talior-Volodarsky, Ilana; Mahou, Redouan; Emili, Andrew; Sefton, Michael V

    2015-08-25

    An unbiased phosphoproteomic method was used to identify biomaterial-associated changes in the phosphorylation patterns of macrophage-like cells. The phosphorylation differences between differentiated THP1 (dTHP1) cells treated for 10, 20, or 30 min with a vascular regenerative methacrylic acid (MAA) copolymer or a control methyl methacrylate (MM) copolymer were determined by MS. There were 1,470 peptides (corresponding to 729 proteins) that were differentially phosphorylated in dTHP1 cells treated with the two materials with a greater cellular response to MAA treatment. In addition to identifying pathways (such as integrin signaling and cytoskeletal arrangement) that are well known to change with cell-material interaction, previously unidentified pathways, such as apoptosis and mRNA splicing, were also discovered. PMID:26261332

  18. Asymptotic rates of response from forest tree breeding strategies using best linear unbiased prediction.

    PubMed

    Kerr, R J

    1998-03-01

    Genetic gain equations are developed for selection on multiple traits using either multi- or univariate best linear unbiased predictors (BLUP) and for selection under controlled and open pollination and polymix mating schemes. The equations assume an infinite population and account for the effects of selection. A comparison with simulated populations under the same mating schemes show that the gain equations predict selection response well, with the predictions having some upward bias. The gain equations are used to compare across mating schemes, to compare univariate to multivariate analyses, and to measure the reduction in the rate of genetic gain due to selection disequilibrium. Results show controlled pollination schemes can offer as much as a 56% advantage in genetic gain relative to open pollination. The reduction in the rate of genetic gain due to selection disequilibrium is approximately 27% under controlled pollination for the breeding goals studied. The results show a limited benefit in using multivariate analyses for predicting breeding values. PMID:24710888

  19. Unbiased reduced density matrices and electronic properties from full configuration interaction quantum Monte Carlo

    SciTech Connect

    Overy, Catherine; Blunt, N. S.; Shepherd, James J.; Booth, George H.; Cleland, Deidre; Alavi, Ali

    2014-12-28

    Properties that are necessarily formulated within pure (symmetric) expectation values are difficult to calculate for projector quantum Monte Carlo approaches, but are critical in order to compute many of the important observable properties of electronic systems. Here, we investigate an approach for the sampling of unbiased reduced density matrices within the full configuration interaction quantum Monte Carlo dynamic, which requires only small computational overheads. This is achieved via an independent replica population of walkers in the dynamic, sampled alongside the original population. The resulting reduced density matrices are free from systematic error (beyond those present via constraints on the dynamic itself) and can be used to compute a variety of expectation values and properties, with rapid convergence to an exact limit. A quasi-variational energy estimate derived from these density matrices is proposed as an accurate alternative to the projected estimator for multiconfigurational wavefunctions, while its variational property could potentially lend itself to accurate extrapolation approaches in larger systems.

  20. An Unbiased Search for Molecular Hydrogen Outflows in the Orion B Star Forming Region

    NASA Astrophysics Data System (ADS)

    Froebrich, D.; Ziener, R.; Eislöffel, J.

    The formation of stars is often accompanied by molecular outflows. One possible tracer of these outflows is the shocked emission of molecular hydrogen in the near-infrared. We conducted an unbiased survey for molecular outflows in the Orion B region with MAGIC at the 1.23 m telescope on Calar Alto in the 1-0 S(1) line of molecular hydrogen at 2.212μm and in the K' bandpass (continuum). The observed field was about 2.7 square degrees, including the known outflows of NGC2071, HH19, HH24, HH25, HH26, HH27, HH37, HH67, HH91, HH92, HH93, HH94, HH212, HH247, HH248, HH249 and HH260. In addition to these known H2 flows, we find ten new groups of H2 emission features, and discuss their morphology and possible outflow sources.

  1. Unbiased phosphoproteomic method identifies the initial effects of a methacrylic acid copolymer on macrophages

    PubMed Central

    Chamberlain, Michael Dean; Wells, Laura A.; Lisovsky, Alexandra; Guo, Hongbo; Isserlin, Ruth; Talior-Volodarsky, Ilana; Mahou, Redouan; Emili, Andrew; Sefton, Michael V.

    2015-01-01

    An unbiased phosphoproteomic method was used to identify biomaterial-associated changes in the phosphorylation patterns of macrophage-like cells. The phosphorylation differences between differentiated THP1 (dTHP1) cells treated for 10, 20, or 30 min with a vascular regenerative methacrylic acid (MAA) copolymer or a control methyl methacrylate (MM) copolymer were determined by MS. There were 1,470 peptides (corresponding to 729 proteins) that were differentially phosphorylated in dTHP1 cells treated with the two materials with a greater cellular response to MAA treatment. In addition to identifying pathways (such as integrin signaling and cytoskeletal arrangement) that are well known to change with cell–material interaction, previously unidentified pathways, such as apoptosis and mRNA splicing, were also discovered. PMID:26261332

  2. Manganese-Mediated C-H Alkylation of Unbiased Arenes Using Alkylboronic Acids.

    PubMed

    Castro, Susana; Fernández, Juan J; Fañanás, Francisco J; Vicente, Rubén; Rodríguez, Félix

    2016-06-27

    The alkylation of arenes is an essential synthetic step of interest not only from the academic point of view but also in the bulk chemical industry. Despite its limitations, the Friedel-Crafts reaction is still the method of choice for most of the arene alkylation processes. Thus, the development of new strategies to synthesize alkyl arenes is a highly desirable goal, and herein, we present an alternative method to those conventional reactions. Particularly, a simple protocol for the direct C-H alkylation of unbiased arenes with alkylboronic acids in the presence of Mn(OAc)3 ⋅2H2 O is reported. Primary or secondary unactivated alkylboronic acids served as alkylating agents for the direct functionalization of representative polyaromatic hydrocarbons (PAHs) or benzene. The results are consistent with a free-radical mechanism. PMID:27124250

  3. Model term selection for spatio-temporal system identification using mutual information

    NASA Astrophysics Data System (ADS)

    Wang, Shu; Wei, Hua-Liang; Coca, Daniel; Billings, Stephen A.

    2013-02-01

    A new mutual information based algorithm is introduced for term selection in spatio-temporal models. A generalised cross validation procedure is also introduced for model length determination and examples based on cellular automata, coupled map lattice and partial differential equations are described.

  4. Inflammation and colorectal cancer, when microbiota-host mutualism breaks

    PubMed Central

    Candela, Marco; Turroni, Silvia; Biagi, Elena; Carbonero, Franck; Rampelli, Simone; Fiorentini, Carla; Brigidi, Patrizia

    2014-01-01

    Structural changes in the gut microbial community have been shown to accompany the progressive development of colorectal cancer. In this review we discuss recent hypotheses on the mechanisms involved in the bacteria-mediated carcinogenesis, as well as the triggering factors favoring the shift of the gut microbiota from a mutualistic to a pro-carcinogenic configuration. The possible role of inflammation, bacterial toxins and toxic microbiota metabolites in colorectal cancer onset is specifically discussed. On the other hand, the strategic role of inflammation as the keystone factor in driving microbiota to become carcinogenic is suggested. As a common outcome of different environmental and endogenous triggers, such as diet, aging, pathogen infection or genetic predisposition, inflammation can compromise the microbiota-host mutualism, forcing the increase of pathobionts at the expense of health-promoting groups, and allowing the microbiota to acquire an overall pro-inflammatory configuration. Consolidating inflammation in the gut, and favoring the bloom of toxigenic bacterial drivers, these changes in the gut microbial ecosystem have been suggested as pivotal in promoting carcinogenesis. In this context, it will become of primary importance to implement dietary or probiotics-based interventions aimed at preserving the microbiota-host mutualism along aging, counteracting deviations that favor a pro-carcinogenic microbiota asset. PMID:24574765

  5. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    PubMed Central

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  6. Mutual information measures applied to EEG signals for sleepiness characterization.

    PubMed

    Melia, Umberto; Guaita, Marc; Vallverdú, Montserrat; Embid, Cristina; Vilaseca, Isabel; Salamero, Manel; Santamaria, Joan

    2015-03-01

    Excessive daytime sleepiness (EDS) is one of the main symptoms of several sleep related disorders with a great impact on the patient lives. While many studies have been carried out in order to assess daytime sleepiness, the automatic EDS detection still remains an open problem. In this work, a novel approach to this issue based on non-linear dynamical analysis of EEG signal was proposed. Multichannel EEG signals were recorded during five maintenance of wakefulness (MWT) and multiple sleep latency (MSLT) tests alternated throughout the day from patients suffering from sleep disordered breathing. A group of 20 patients with excessive daytime sleepiness (EDS) was compared with a group of 20 patients without daytime sleepiness (WDS), by analyzing 60-s EEG windows in waking state. Measures obtained from cross-mutual information function (CMIF) and auto-mutual-information function (AMIF) were calculated in the EEG. These functions permitted a quantification of the complexity properties of the EEG signal and the non-linear couplings between different zones of the scalp. Statistical differences between EDS and WDS groups were found in β band during MSLT events (p-value < 0.0001). WDS group presented more complexity than EDS in the occipital zone, while a stronger nonlinear coupling between occipital and frontal zones was detected in EDS patients than in WDS. The AMIF and CMIF measures yielded sensitivity and specificity above 80% and AUC of ROC above 0.85 in classifying EDS and WDS patients. PMID:25638417

  7. Mutual influences of pain and emotional face processing

    PubMed Central

    Wieser, Matthias J.; Gerdes, Antje B. M.; Reicherts, Philipp; Pauli, Paul

    2014-01-01

    The perception of unpleasant stimuli enhances whereas the perception of pleasant stimuli decreases pain perception. In contrast, the effects of pain on the processing of emotional stimuli are much less known. Especially given the recent interest in facial expressions of pain as a special category of emotional stimuli, a main topic in this research line is the mutual influence of pain and facial expression processing. Therefore, in this mini-review we selectively summarize research on the effects of emotional stimuli on pain, but more extensively turn to the opposite direction namely how pain influences concurrent processing of affective stimuli such as facial expressions. Based on the motivational priming theory one may hypothesize that the perception of pain enhances the processing of unpleasant stimuli and decreases the processing of pleasant stimuli. This review reveals that the literature is only partly consistent with this assumption: pain reduces the processing of pleasant pictures and happy facial expressions, but does not – or only partly – affect processing of unpleasant pictures. However, it was demonstrated that pain selectively enhances the processing of facial expressions if these are pain-related (i.e., facial expressions of pain). Extending a mere affective modulation theory, the latter results suggest pain-specific effects which may be explained by the perception-action model of empathy. Together, these results underscore the important mutual influence of pain and emotional face processing. PMID:25352817

  8. Discrete Lognormal Model as an Unbiased Quantitative Measure of Scientific Performance Based on Empirical Citation Data

    NASA Astrophysics Data System (ADS)

    Moreira, Joao; Zeng, Xiaohan; Amaral, Luis

    2013-03-01

    Assessing the career performance of scientists has become essential to modern science. Bibliometric indicators, like the h-index are becoming more and more decisive in evaluating grants and approving publication of articles. However, many of the more used indicators can be manipulated or falsified by publishing with very prolific researchers or self-citing papers with a certain number of citations, for instance. Accounting for these factors is possible but it introduces unwanted complexity that drives us further from the purpose of the indicator: to represent in a clear way the prestige and importance of a given scientist. Here we try to overcome this challenge. We used Thompson Reuter's Web of Science database and analyzed all the papers published until 2000 by ~1500 researchers in the top 30 departments of seven scientific fields. We find that over 97% of them have a citation distribution that is consistent with a discrete lognormal model. This suggests that our model can be used to accurately predict the performance of a researcher. Furthermore, this predictor does not depend on the individual number of publications and is not easily ``gamed'' on. The authors acknowledge support from FCT Portugal, and NSF grants

  9. A Bayesian Alternative to Mutual Information for the Hierarchical Clustering of Dependent Random Variables

    PubMed Central

    Marrelec, Guillaume; Messé, Arnaud; Bellec, Pierre

    2015-01-01

    The use of mutual information as a similarity measure in agglomerative hierarchical clustering (AHC) raises an important issue: some correction needs to be applied for the dimensionality of variables. In this work, we formulate the decision of merging dependent multivariate normal variables in an AHC procedure as a Bayesian model comparison. We found that the Bayesian formulation naturally shrinks the empirical covariance matrix towards a matrix set a priori (e.g., the identity), provides an automated stopping rule, and corrects for dimensionality using a term that scales up the measure as a function of the dimensionality of the variables. Also, the resulting log Bayes factor is asymptotically proportional to the plug-in estimate of mutual information, with an additive correction for dimensionality in agreement with the Bayesian information criterion. We investigated the behavior of these Bayesian alternatives (in exact and asymptotic forms) to mutual information on simulated and real data. An encouraging result was first derived on simulations: the hierarchical clustering based on the log Bayes factor outperformed off-the-shelf clustering techniques as well as raw and normalized mutual information in terms of classification accuracy. On a toy example, we found that the Bayesian approaches led to results that were similar to those of mutual information clustering techniques, with the advantage of an automated thresholding. On real functional magnetic resonance imaging (fMRI) datasets measuring brain activity, it identified clusters consistent with the established outcome of standard procedures. On this application, normalized mutual information had a highly atypical behavior, in the sense that it systematically favored very large clusters. These initial experiments suggest that the proposed Bayesian alternatives to mutual information are a useful new tool for hierarchical clustering. PMID:26406245

  10. A Bayesian Alternative to Mutual Information for the Hierarchical Clustering of Dependent Random Variables.

    PubMed

    Marrelec, Guillaume; Messé, Arnaud; Bellec, Pierre

    2015-01-01

    The use of mutual information as a similarity measure in agglomerative hierarchical clustering (AHC) raises an important issue: some correction needs to be applied for the dimensionality of variables. In this work, we formulate the decision of merging dependent multivariate normal variables in an AHC procedure as a Bayesian model comparison. We found that the Bayesian formulation naturally shrinks the empirical covariance matrix towards a matrix set a priori (e.g., the identity), provides an automated stopping rule, and corrects for dimensionality using a term that scales up the measure as a function of the dimensionality of the variables. Also, the resulting log Bayes factor is asymptotically proportional to the plug-in estimate of mutual information, with an additive correction for dimensionality in agreement with the Bayesian information criterion. We investigated the behavior of these Bayesian alternatives (in exact and asymptotic forms) to mutual information on simulated and real data. An encouraging result was first derived on simulations: the hierarchical clustering based on the log Bayes factor outperformed off-the-shelf clustering techniques as well as raw and normalized mutual information in terms of classification accuracy. On a toy example, we found that the Bayesian approaches led to results that were similar to those of mutual information clustering techniques, with the advantage of an automated thresholding. On real functional magnetic resonance imaging (fMRI) datasets measuring brain activity, it identified clusters consistent with the established outcome of standard procedures. On this application, normalized mutual information had a highly atypical behavior, in the sense that it systematically favored very large clusters. These initial experiments suggest that the proposed Bayesian alternatives to mutual information are a useful new tool for hierarchical clustering. PMID:26406245

  11. Unbiased characterization of three-phase microstructure of porous lanthanum doped strontium manganite/yttria-stabilized zirconia composite cathodes for solid oxide fuel cells using atomic force microscopy and stereology

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Lynch, M.; Gokhale, A. M.; Liu, M.

    Microstructural characteristics of porous LSM/YSZ composite cathodes greatly influence the performance of solid oxide fuel cells. The triple phase boundaries, for example, account for a significant portion of the electrochemically active sites in these porous composite cathodes. Nonetheless, experimental characterization of the relevant microstructural attributes has been problematic due to lack of suitable microscopy techniques for simultaneous observations of all three phases (i.e., LSM, YSZ, and porosity) needed for identification and unbiased characterization of the triple phase boundaries. In this contribution it is shown that a combination of chemical etching and atomic force microscopy clearly reveals all three phases and the triple phase junctions in the microstructural sections. Further, stereological techniques based on the geometric probabilities of stochastic geometry enable unbiased statistical estimation of total triple phase boundary length per unit volume and other microstructural attributes from simple counting measurements performed on representative microstructural sections.

  12. Random Tagging Genotyping by Sequencing (rtGBS), an Unbiased Approach to Locate Restriction Enzyme Sites across the Target Genome

    PubMed Central

    Hilario, Elena; Barron, Lorna; Deng, Cecilia H.; Datson, Paul M.; Davy, Marcus W.; Storey, Roy D.

    2015-01-01

    Genotyping by sequencing (GBS) is a restriction enzyme based targeted approach developed to reduce the genome complexity and discover genetic markers when a priori sequence information is unavailable. Sufficient coverage at each locus is essential to distinguish heterozygous from homozygous sites accurately. The number of GBS samples able to be pooled in one sequencing lane is limited by the number of restriction sites present in the genome and the read depth required at each site per sample for accurate calling of single-nucleotide polymorphisms. Loci bias was observed using a slight modification of the Elshire et al. method: some restriction enzyme sites were represented in higher proportions while others were poorly represented or absent. This bias could be due to the quality of genomic DNA, the endonuclease and ligase reaction efficiency, the distance between restriction sites, the preferential amplification of small library restriction fragments, or bias towards cluster formation of small amplicons during the sequencing process. To overcome these issues, we have developed a GBS method based on randomly tagging genomic DNA (rtGBS). By randomly landing on the genome, we can, with less bias, find restriction sites that are far apart, and undetected by the standard GBS (stdGBS) method. The study comprises two types of biological replicates: six different kiwifruit plants and two independent DNA extractions per plant; and three types of technical replicates: four samples of each DNA extraction, stdGBS vs. rtGBS methods, and two independent library amplifications, each sequenced in separate lanes. A statistically significant unbiased distribution of restriction fragment size by rtGBS showed that this method targeted 49% (39,145) of BamH I sites shared with the reference genome, compared to only 14% (11,513) by stdGBS. PMID:26633193

  13. Nutrient loading alters the performance of key nutrient exchange mutualisms.

    PubMed

    Shantz, Andrew A; Lemoine, Nathan P; Burkepile, Deron E

    2016-01-01

    Nutrient exchange mutualisms between phototrophs and heterotrophs, such as plants and mycorrhizal fungi or symbiotic algae and corals, underpin the functioning of many ecosystems. These relationships structure communities, promote biodiversity and help maintain food security. Nutrient loading may destabilise these mutualisms by altering the costs and benefits each partner incurs from interacting. Using meta-analyses, we show a near ubiquitous decoupling in mutualism performance across terrestrial and marine environments in which phototrophs benefit from enrichment at the expense of their heterotrophic partners. Importantly, heterotroph identity, their dependence on phototroph-derived C and the type of nutrient enrichment (e.g. nitrogen vs. phosphorus) mediated the responses of different mutualisms to enrichment. Nutrient-driven changes in mutualism performance may alter community organisation and ecosystem processes and increase costs of food production. Consequently, the decoupling of nutrient exchange mutualisms via alterations of the world's nitrogen and phosphorus cycles may represent an emerging threat of global change. PMID:26549314

  14. Concurrent behavior: Are the interpretations mutually exclusive?

    PubMed Central

    Lyon, David O.

    1982-01-01

    The experimental literature is replete with examples of behavior which occur concurrently with a schedule of reinforcement. These concurrent behaviors, often with similar topographies and occurring under like circumstances, may be interpreted as functionally autonomous, collateral, adjunctive, superstitious or mediating behavior. The degree to which the interaction of concurrent and schedule controlled behavior is used in the interpretation of behavior illustrated the importance of distinguishing among these interpretations by experimental procedure. The present paper reviews the characteristics of these interpretations, and discusses the experimental procedures necessary to distinguish among them. The paper concludes that the interpretations are mutually exclusive and refer to distinct behaviors, but that the distinction between any two of the interpretations requires more than one experimental procedure. PMID:22478568

  15. Mutually-antagonistic interactions in baseball networks

    NASA Astrophysics Data System (ADS)

    Saavedra, Serguei; Powers, Scott; McCotter, Trent; Porter, Mason A.; Mucha, Peter J.

    2010-03-01

    We formulate the head-to-head matchups between Major League Baseball pitchers and batters from 1954 to 2008 as a bipartite network of mutually-antagonistic interactions. We consider both the full network and single-season networks, which exhibit structural changes over time. We find interesting structure in the networks and examine their sensitivity to baseball’s rule changes. We then study a biased random walk on the matchup networks as a simple and transparent way to (1) compare the performance of players who competed under different conditions and (2) include information about which particular players a given player has faced. We find that a player’s position in the network does not correlate with his placement in the random walker ranking. However, network position does have a substantial effect on the robustness of ranking placement to changes in head-to-head matchups.

  16. Mutual Contextualization in Tripartite Graphs of Folksonomies

    NASA Astrophysics Data System (ADS)

    Yeung, Ching-Man Au; Gibbins, Nicholas; Shadbolt, Nigel

    The use of tags to describe Web resources in a collaborative manner has experienced rising popularity among Web users in recent years. The product of such activity is given the name folksonomy, which can be considered as a scheme of organizing information in the users' own way. This research work attempts to analyze tripartite graphs - graphs involving users, tags and resources - of folksonomies and discuss how these elements acquire their semantics through their associations with other elements, a process we call mutual contextualization. By studying such process, we try to identify solutions to problems such as tag disambiguation, retrieving documents of similar topics and discovering communities of users. This paper describes the basis of the research work, mentions work done so far and outlines future plans.

  17. Detecting Generalized Synchrony Through Mutual Prediction

    NASA Astrophysics Data System (ADS)

    Schiff, Steven J.; So, Paul

    1996-03-01

    Detection of synchrony in the nervous system has traditionally relied on linear methods such as cross correlation and coherence. Neurons are floridly nonlinear, however, and neuronal interactions may be inadequately described if it is assumed that ensemble behavior is a linear combination of neuronal activities. We develop an approach to detecting generalized synchrony using mutual nonlinear prediction. Multivariate surrogate data will be employed to establish statistical confidence that synchrony is nonlinear. These results will be applied to an experimental preparation - the motoneuron pool from the spinal cord stretch reflex. The interrelationships between individual neurons, between single neurons and the population of neurons, and between intracellular synaptic currents and single neurons will be examined, and the case for the existence of generalized synchrony made.

  18. Unbiased Selection of Peptide-Peptoid Hybrids Specific for Lung Cancer Compared to Normal Lung Epithelial Cells.

    PubMed

    Matharage, Jaya M; Minna, John D; Brekken, Rolf A; Udugamasooriya, D Gomika

    2015-12-18

    To develop widely applicable diagnostic and potentially therapeutic approaches overcoming protein heterogeneity in human cancer, we have developed a technology to unbiasedly select high specificity compound(s) that bind any biomolecule (e.g., proteins, lipids, carbohydrates) presented on the cancer cell surface but not on normal cells. We utilized a peptidomimetic based on-bead two-color (OBTC) combinatorial cell screen that can detect differences between two cell surfaces at high accuracy by looking for beads (where each bead in the library had one peptide-peptoid hybrid on the surface) that only bound cancer but not normal cells. We screened a library of 393 216 compounds targeting HCC4017 lung adenocarcinoma cells (labeled in red) in the presence of HBEC30KT normal bronchial epithelial cells (labeled in green) derived from the same tissue of the same patient. This screen identified a peptide-peptoid hybrid called PPS1 which displayed high specific binding for HCC4017 cancer cells over HBEC30KT cells. Specificity was validated through on-bead, ELISA-like and magnetic bead pulldown studies, while a scrambled version of PPS1 did not show any binding. Of interest, the simple dimeric version (PPS1D1) displayed cytotoxic activity on HCC4017 cells, but not on normal HBEC30KT cells. PPS1D1 also strongly accumulated in HCC4017 lung cancer xenografts in mice over control constructs. We conclude that such combinatorial screens using tumor and normal cells from the same patient have significant potential to develop new reagents for cancer biology, diagnosis, and potentially therapy. PMID:26509598

  19. Nanoscale Synaptic Membrane Mimetic Allows Unbiased High Throughput Screen That Targets Binding Sites for Alzheimer’s-Associated Aβ Oligomers

    PubMed Central

    Wilcox, Kyle C.; Marunde, Matthew R.; Das, Aditi; Velasco, Pauline T.; Kuhns, Benjamin D.; Marty, Michael T.; Jiang, Haoming; Luan, Chi-Hao; Sligar, Stephen G.; Klein, William L.

    2015-01-01

    Despite their value as sources of therapeutic drug targets, membrane proteomes are largely inaccessible to high-throughput screening (HTS) tools designed for soluble proteins. An important example comprises the membrane proteins that bind amyloid β oligomers (AβOs). AβOs are neurotoxic ligands thought to instigate the synapse damage that leads to Alzheimer’s dementia. At present, the identities of initial AβO binding sites are highly uncertain, largely because of extensive protein-protein interactions that occur following attachment of AβOs to surface membranes. Here, we show that AβO binding sites can be obtained in a state suitable for unbiased HTS by encapsulating the solubilized synaptic membrane proteome into nanoscale lipid bilayers (Nanodiscs). This method gives a soluble membrane protein library (SMPL)—a collection of individualized synaptic proteins in a soluble state. Proteins within SMPL Nanodiscs showed enzymatic and ligand binding activity consistent with conformational integrity. AβOs were found to bind SMPL Nanodiscs with high affinity and specificity, with binding dependent on intact synaptic membrane proteins, and selective for the higher molecular weight oligomers known to accumulate at synapses. Combining SMPL Nanodiscs with a mix-incubate-read chemiluminescence assay provided a solution-based HTS platform to discover antagonists of AβO binding. Screening a library of 2700 drug-like compounds and natural products yielded one compound that potently reduced AβO binding to SMPL Nanodiscs, synaptosomes, and synapses in nerve cell cultures. Although not a therapeutic candidate, this small molecule inhibitor of synaptic AβO binding will provide a useful experimental antagonist for future mechanistic studies of AβOs in Alzheimer’s model systems. Overall, results provide proof of concept for using SMPLs in high throughput screening for AβO binding antagonists, and illustrate in general how a SMPL Nanodisc system can facilitate drug

  20. DOA Estimation under Unknown Mutual Coupling and Multipath with Improved Effective Array Aperture.

    PubMed

    Wang, Yuexian; Trinkle, Matthew; Ng, Brian W-H

    2015-01-01

    Subspace-based high-resolution direction of arrival (DOA) estimation significantly deteriorates under array manifold perturbation and rank deficiency of the covariance matrix due to mutual coupling and multipath propagation, respectively. In this correspondence, the unknown mutual coupling can be circumvented by the proposed method without any passive or active calibration process, and the DOA of the coherent signals can be accurately estimated accordingly. With a newly constructed matrix, the deficient rank can be restored, and the effective array aperture can be extended compared with conventional spatial smoothing. The proposed method achieves a good robustness and DOA estimation accuracy with unknown mutual coupling. The simulation results demonstrate the validity and efficiency of the proposed method. PMID:26670235

  1. Mutuality and reciprocity in the psychological contracts of employees and employers.

    PubMed

    Dabos, Guillermo E; Rousseau, Denise M

    2004-02-01

    The authors assessed the joint perceptions of the employee and his or her employer to examine mutuality and reciprocity in the employment relationship. Paired psychological contract reports were obtained from 80 employee-employer dyads in 16 university-based research centers. On the basis of in-depth study of the research setting, research directors were identified as primary agents for the university (employer) in shaping the terms of employment of staff scientists (employees). By assessing the extent of consistency between employee and employer beliefs regarding their exchange agreement, the present study mapped the variation and consequences of mutuality and reciprocity in psychological contracts. Results indicate that both mutuality and reciprocity are positively related to archival indicators of research productivity and career advancement, in addition to self-reported measures of Met Expectations and intention to continue working with the employer. Implications for psychological contract theory are presented. PMID:14769120

  2. DOA Estimation under Unknown Mutual Coupling and Multipath with Improved Effective Array Aperture

    PubMed Central

    Wang, Yuexian; Trinkle, Matthew; Ng, Brian W.-H.

    2015-01-01

    Subspace-based high-resolution direction of arrival (DOA) estimation significantly deteriorates under array manifold perturbation and rank deficiency of the covariance matrix due to mutual coupling and multipath propagation, respectively. In this correspondence, the unknown mutual coupling can be circumvented by the proposed method without any passive or active calibration process, and the DOA of the coherent signals can be accurately estimated accordingly. With a newly constructed matrix, the deficient rank can be restored, and the effective array aperture can be extended compared with conventional spatial smoothing. The proposed method achieves a good robustness and DOA estimation accuracy with unknown mutual coupling. The simulation results demonstrate the validity and efficiency of the proposed method. PMID:26670235

  3. Unbiased analysis of pancreatic cancer radiation resistance reveals cholesterol biosynthesis as a novel target for radiosensitisation

    PubMed Central

    Souchek, J J; Baine, M J; Lin, C; Rachagani, S; Gupta, S; Kaur, S; Lester, K; Zheng, D; Chen, S; Smith, L; Lazenby, A; Johansson, S L; Jain, M; Batra, S K

    2014-01-01

    Background: Despite its promise as a highly useful therapy for pancreatic cancer (PC), the addition of external beam radiation therapy to PC treatment has shown varying success in clinical trials. Understanding PC radioresistance and discovery of methods to sensitise PC to radiation will increase patient survival and improve quality of life. In this study, we identified PC radioresistance-associated pathways using global, unbiased techniques. Methods: Radioresistant cells were generated by sequential irradiation and recovery, and global genome cDNA microarray analysis was performed to identify differentially expressed genes in radiosensitive and radioresistant cells. Ingenuity pathway analysis was performed to discover cellular pathways and functions associated with differential radioresponse and identify potential small-molecule inhibitors for radiosensitisation. The expression of FDPS, one of the most differentially expressed genes, was determined in human PC tissues by IHC and the impact of its pharmacological inhibition with zoledronic acid (ZOL, Zometa) on radiosensitivity was determined by colony-forming assays. The radiosensitising effect of Zol in vivo was determined using allograft transplantation mouse model. Results: Microarray analysis indicated that 11 genes (FDPS, ACAT2, AG2, CLDN7, DHCR7, ELFN2, FASN, SC4MOL, SIX6, SLC12A2, and SQLE) were consistently associated with radioresistance in the cell lines, a majority of which are involved in cholesterol biosynthesis. We demonstrated that knockdown of farnesyl diphosphate synthase (FDPS), a branchpoint enzyme of the cholesterol synthesis pathway, radiosensitised PC cells. FDPS was significantly overexpressed in human PC tumour tissues compared with healthy pancreas samples. Also, pharmacologic inhibition of FDPS by ZOL radiosensitised PC cell lines, with a radiation enhancement ratio between 1.26 and 1.5. Further, ZOL treatment resulted in radiosensitisation of PC tumours in an allograft mouse model

  4. Unbiased, High-Throughput Electron Microscopy Analysis of Experience-Dependent Synaptic Changes in the Neocortex

    PubMed Central

    Chandrasekaran, Santosh; Navlakha, Saket; Audette, Nicholas J.; McCreary, Dylan D.; Suhan, Joe; Bar-Joseph, Ziv

    2015-01-01

    Neocortical circuits can be altered by sensory and motor experience, with experimental evidence supporting both anatomical and electrophysiological changes in synaptic properties. Previous studies have focused on changes in specific neurons or pathways—for example, the thalamocortical circuitry, layer 4–3 (L4–L3) synapses, or in the apical dendrites of L5 neurons— but a broad-scale analysis of experience-induced changes across the cortical column has been lacking. Without this comprehensive approach, a full understanding of how cortical circuits adapt during learning or altered sensory input will be impossible. Here we adapt an electron microscopy technique that selectively labels synapses, in combination with a machine-learning algorithm for semiautomated synapse detection, to perform an unbiased analysis of developmental and experience-dependent changes in synaptic properties across an entire cortical column in mice. Synapse density and length were compared across development and during whisker-evoked plasticity. Between postnatal days 14 and 18, synapse density significantly increases most in superficial layers, and synapse length increases in L3 and L5B. Removal of all but a single whisker row for 24 h led to an apparent increase in synapse density in L2 and a decrease in L6, and a significant increase in length in L3. Targeted electrophysiological analysis of changes in miniature EPSC and IPSC properties in L2 pyramidal neurons showed that mEPSC frequency nearly doubled in the whisker-spared column, a difference that was highly significant. Together, this analysis shows that data-intensive analysis of column-wide changes in synapse properties can generate specific and testable hypotheses about experience-dependent changes in cortical organization. SIGNIFICANCE STATEMENT Development and sensory experience can change synapse properties in the neocortex. Here we use a semiautomated analysis of electron microscopy images for an unbiased, column

  5. Necessity of Mutual Understandings in Supply Chain Management of Lithium-Ion Battery for Space Vehicle

    NASA Astrophysics Data System (ADS)

    Kiyokawa, T.; Nakajima, M.; Mori, Y.

    2012-01-01

    Application of Lithium Ion Battery (LIB) is getting growth these days in space industry. Through the supply chain of LIB, it is very important to establish deepen mutual understandings between space industry people and non-space industry people in order to meet requirements of space grade quality control. Furthermore, this approach has positive effects for safety handling and safety transportation. This paper explains necessity of mutual understandings based on the analysis of aviation incident report. The study is focused on its background and issues on each related industry. These contents are studied and discussed in the New Work Item Proposal of the International Standard of LIB for space vehicle.

  6. Mutual Comparative Filtering for Change Detection in Videos with Unstable Illumination Conditions

    NASA Astrophysics Data System (ADS)

    Sidyakin, Sergey V.; Vishnyakov, Boris V.; Vizilter, Yuri V.; Roslov, Nikolay I.

    2016-06-01

    In this paper we propose a new approach for change detection and moving objects detection in videos with unstable, abrupt illumination changes. This approach is based on mutual comparative filters and background normalization. We give the definitions of mutual comparative filters and outline their strong advantage for change detection purposes. Presented approach allows us to deal with changing illumination conditions in a simple and efficient way and does not have drawbacks, which exist in models that assume different color transformation laws. The proposed procedure can be used to improve a number of background modelling methods, which are not specifically designed to work under illumination changes.

  7. A secure RFID mutual authentication protocol for healthcare environments using elliptic curve cryptography.

    PubMed

    Jin, Chunhua; Xu, Chunxiang; Zhang, Xiaojun; Zhao, Jining

    2015-03-01

    Radio Frequency Identification(RFID) is an automatic identification technology, which can be widely used in healthcare environments to locate and track staff, equipment and patients. However, potential security and privacy problems in RFID system remain a challenge. In this paper, we design a mutual authentication protocol for RFID based on elliptic curve cryptography(ECC). We use pre-computing method within tag's communication, so that our protocol can get better efficiency. In terms of security, our protocol can achieve confidentiality, unforgeability, mutual authentication, tag's anonymity, availability and forward security. Our protocol also can overcome the weakness in the existing protocols. Therefore, our protocol is suitable for healthcare environments. PMID:25666925

  8. Reservoir computing with a slowly modulated mask signal for preprocessing using a mutually coupled optoelectronic system

    NASA Astrophysics Data System (ADS)

    Tezuka, Miwa; Kanno, Kazutaka; Bunsen, Masatoshi

    2016-08-01

    Reservoir computing is a machine-learning paradigm based on information processing in the human brain. We numerically demonstrate reservoir computing with a slowly modulated mask signal for preprocessing by using a mutually coupled optoelectronic system. The performance of our system is quantitatively evaluated by a chaotic time series prediction task. Our system can produce comparable performance with reservoir computing with a single feedback system and a fast modulated mask signal. We showed that it is possible to slow down the modulation speed of the mask signal by using the mutually coupled system in reservoir computing.

  9. Positive Illusions and Forecasting Errors in Mutual Fund Investment Decisions.

    PubMed

    Moore; Kurtzberg; Fox; Bazerman

    1999-08-01

    This study examines the portfolio allocation decisions of 80 business students in a computer-based investing simulation. Our goal was to better understand why investors spend so much time and money on actively managed mutual funds despite the fact that the vast majority of these funds are outperformed by pas sively managed index funds. Participants' judgments and decisions provided evidence for a number of biases. First, most participants consistently overestimated both the future perfor mance and the past performance of their investments. Second, participants overestimated the intertemporal consistency of portfolio performance. Third, participants were more likely to shift their portfolio allocation following poorer performance than following better performance, and this tendency had a negative impact on portfolio returns. We speculate that these biases in investor behavior may contribute to suboptimal investment decisions in real financial markets. Copyright 1999 Academic Press. PMID:10433899

  10. Blasting and Zipping: Sequence Alignment and Mutual Information

    NASA Astrophysics Data System (ADS)

    Penner, Orion; Grassberger, Peter; Paczuski, Maya

    2009-03-01

    Alignment of biological sequences such as DNA, RNA or proteins is one of the most widely used tools in computational bioscience. While the accomplishments of sequence alignment algorithms are undeniable the fact remains that these algorithms are based upon heuristic scoring schemes. Therefore, these algorithms do not provide model independent and objective measures for how similar two (or more) sequences actually are. Although information theory provides such a similarity measure - the mutual information (MI) - numerous previous attempts to connect sequence alignment and information have not produced realistic estimates for the MI from a given alignment. We report on a simple and flexible approach to get robust estimates of MI from global alignments. The presented results may help establish MI as a reliable tool for evaluating the quality of global alignments, judging the relative merits of different alignment algorithms, and estimating the significance of specific alignments.

  11. Mutual neutralization at low collision energies: the power of imaging

    NASA Astrophysics Data System (ADS)

    Vassantachart, April K.; Romano, Shalynn L.; Martin, Merl F.; Andrianarijaona, Vola M.; O'Connor, Aodh; Urbain, Xavier

    2014-05-01

    Mutual neutralization studies are generally limited to energies above a few eV, and do not specify the electronic state of the products, merely indicating a band of principal quantum numbers based on time-of-flight intervals. We upgraded our merged beam set-up to reach meV collision energies, and incorporated three-dimensional product imaging. Besides providing clear coincidence signals, this technique gives unambiguous identification of the electronic states of the products. Knowing their angular distribution at the different collision energies allows absolute cross sections to be retrieved. Results for the H+/H-andHe+/H- systems will be presented, providing detailed branching ratios for non-degenerate channels. This research is supported by the Fund for Scientific Research - FNRS through IISN Grant No. 4.4504.10, and the National Science Foundation through Grant No. PHY-106887.

  12. Mutual neutralization at low collision energies: the power of imaging

    NASA Astrophysics Data System (ADS)

    Vassantachart, April K.; Romano, Shalynn L.; Martin, Merl F.; Andrianarijaona, Vola M.; Urbain, Xavier

    2014-03-01

    Mutual neutralization studies are generally limited to energies above a few eV, and do not specify the electronic state of the products, merely indicating a band of principal quantum numbers based on time-of-flight intervals (Terao et al., Europhys. Lett. 1 (1986) 123). We upgraded our merged beam set-up to reach meV collision energies, and incorporated three-dimensional product imaging. Besides providing clear coincidence signals, this technique gives unambiguous identification of the electronic states of the products. Knowing their angular distribution at the different collision energies allows absolute cross sections to be retrieved. Results for the H+/H-andHe+/H- systems will be presented, providing detailed branching ratios for non-degenerate channels. This research is supported by the Fund for Scientific Research - FNRS through IISN Grant No. 4.4504.10, and the National Science Foundation through Grant No. PHY-106887.

  13. Unbiased Resource Evaluations with Kriging and Stochastic Models of Heterogeneous Rock Properties

    SciTech Connect

    Vargas-Guzman, J.A.

    2008-12-15

    This paper revisits the computation of product combinations for quantification of resources (e.g., pore volume for hydrocarbon reservoir formations). The explanations have been simplified by considering the exhaustive numerical model for properties that are multiplied first and then added or averaged for evaluation. The analysis starts without any probabilistic considerations. Abbreviated (up-scaled) computations in the sum of multiplications are proposed by substituting the individual values by averages for each rock property in the coarser cell resolution model. A result found is that averaged properties can be utilized for estimation at non-sampled locations, instead of individual values; however, covariances and cumulants must also be included in the abbreviated computations. The smoothing effect of kriging is found to be irrelevant if the kriging variance is also included in the up-scaled abbreviated pore volume computations. Thus, the equivalence between computation of resource volumes from kriging estimates and conditional stochastic simulations is established, with the condition that numerical estimation must incorporate the complete covariance and cumulant information as well. An example shows pore volume prediction from a kriging model matches the unbiased result from stochastic simulations.

  14. Quantification of Cysteinyl-S-Nitrosylation by Fluorescence in Unbiased Proteomic Studies*

    PubMed Central

    Wiktorowicz, John E.; Stafford, Susan; Rea, Harriet; Urvil, Petri; Soman, Kizhake; Kurosky, Alexander; Perez-Polo, J. Regino; Savidge, Tor C.

    2011-01-01

    Cysteinyl-S-nitrosylation has emerged as an important post-translational modification affecting protein function in health and disease. Great emphasis has been placed on global, unbiased quantification of S-nitrosylated proteins due to physiologic and oxidative stimuli. However, current strategies have been hampered by sample loss and altered protein electrophoretic mobility. Here, we describe a novel quantitative approach that combines accurate, sensitive fluorescence modification of cysteine S-nitrosylation that leaves electrophoretic mobility unaffected (SNOFlo), and introduce unique concepts for measuring changes in S-nitrosylation status relative to protein abundance. Its efficacy in defining the functional S-nitrosoproteome is demonstrated in two diverse biological applications: an in vivo rat hypoxia-ischemia reperfusion model, and antimicrobial S-nitrosoglutathione-driven transnitrosylation of an enteric microbial pathogen. The suitability of this approach for investigating endogenous S-nitrosylation is further demonstrated using Ingenuity Pathways analysis that identified nervous system and cellular development networks as the top two networks. Functional analysis of differentially S-nitrosylated proteins indicated their involvement in apoptosis, branching morphogenesis of axons, cortical neurons, and sympathetic neurites, neurogenesis, and calcium signaling. Major abundance changes were also observed for fibrillar proteins known to be stress-responsive in neurons and glia. Thus, both examples demonstrate the technique’s power in confirming the widespread involvement of S-nitrosylation in hypoxia-ischemia/reperfusion injury and in antimicrobial host responses. PMID:21615140

  15. Free energies from dynamic weighted histogram analysis using unbiased Markov state model.

    PubMed

    Rosta, Edina; Hummer, Gerhard

    2015-01-13

    The weighted histogram analysis method (WHAM) is widely used to obtain accurate free energies from biased molecular simulations. However, WHAM free energies can exhibit significant errors if some of the biasing windows are not fully equilibrated. To account for the lack of full equilibration, we develop the dynamic histogram analysis method (DHAM). DHAM uses a global Markov state model to obtain the free energy along the reaction coordinate. A maximum likelihood estimate of the Markov transition matrix is constructed by joint unbiasing of the transition counts from multiple umbrella-sampling simulations along discretized reaction coordinates. The free energy profile is the stationary distribution of the resulting Markov matrix. For this matrix, we derive an explicit approximation that does not require the usual iterative solution of WHAM. We apply DHAM to model systems, a chemical reaction in water treated using quantum-mechanics/molecular-mechanics (QM/MM) simulations, and the Na(+) ion passage through the membrane-embedded ion channel GLIC. We find that DHAM gives accurate free energies even in cases where WHAM fails. In addition, DHAM provides kinetic information, which we here use to assess the extent of convergence in each of the simulation windows. DHAM may also prove useful in the construction of Markov state models from biased simulations in phase-space regions with otherwise low population. PMID:26574225

  16. Unbiased analysis of senescence associated secretory phenotype (SASP) to identify common components following different genotoxic stresses.

    PubMed

    Özcan, Servet; Alessio, Nicola; Acar, Mustafa B; Mert, Eda; Omerli, Fatih; Peluso, Gianfranco; Galderisi, Umberto

    2016-07-01

    Senescent cells secrete senescence-associated secretory phenotype (SASP) proteins to carry out several functions, such as sensitizing surrounding cells to senesce; immunomodulation; impairing or fostering cancer growth; and promoting tissue development. Identifying secreted factors that achieve such tasks is a challenging issue since the profile of secreted proteins depends on genotoxic stress and cell type. Currently, researchers are trying to identify common markers for SASP. The present investigation compared the secretome composition of five different senescent phenotypes in two different cell types: bone marrow and adipose mesenchymal stromal cells (MSC). We induced MSC senescence by oxidative stress, doxorubicin treatment, X-ray irradiation, and replicative exhaustion. We took advantage of LC-MS/MS proteome identification and subsequent gene ontology (GO) evaluation to perform an unbiased analysis (hypothesis free manner) of senescent secretomes. GO analysis allowed us to distribute SASP components into four classes: extracellular matrix/cytoskeleton/cell junctions; metabolic processes; ox-redox factors; and regulators of gene expression. We used Ingenuity Pathway Analysis (IPA) to determine common pathways among the different senescent phenotypes. This investigation, along with identification of eleven proteins that were exclusively expressed in all the analyzed senescent phenotypes, permitted the identification of three key signaling paths: MMP2 - TIMP2; IGFBP3 - PAI-1; and Peroxiredoxin 6 - ERP46 - PARK7 - Cathepsin D - Major vault protein. We suggest that these paths could be involved in the paracrine circuit that induces senescence in neighboring cells and may confer apoptosis resistance to senescent cells. PMID:27288264

  17. An Unbiased Screen Identifies the DEP-1 Tumour Suppressor as a Phosphatase Controlling EGFR Endocytosis

    PubMed Central

    Tarcic, Gabi; Boguslavsky, Shlomit K.; Wakim, Jean; Kiuchi, Tai; Liu, Angela; Reinitz, Felicia; Nathanson, David; Takahashi, Takamune; Mischel, Paul S.; Ng, Tony; Yarden, Yosef

    2009-01-01

    Background The epidermal growth factor (EGF) stimulates rapid tyrosine phosphorylation of EGF-receptor (EGFR). This event precedes signalling from both the plasma membrane and from endosomes, and it is essential for recruitment of an ubiquitin ligase, CBL, that sorts activated receptors to endosomes and degradation. Because hyper-phosphorylation of EGFR is involved in oncogenic pathways, we performed an unbiased screen of siRNA oilgonucleotides targeting all human tyrosine phosphatases. Results We report the identification of PTPRK and PTPRJ (DEP-1) as EGFR-targeting phosphatases. DEP-1 is a tumour suppressor that dephosphorylates, thereby stabilizes EGFR by hampering its ability to associate with the CBL-GRB2 ubiquitin ligase complex. DEP-1 silencing enhanced tyrosine phosphorylation of endosomal EGFRs and, accordingly, increased cell proliferation. In line with functional interactions, EGFR and DEP-1 form physical associations, and EGFR phosphorylates a substrtae trapping mutant of DEP-1. Interestingly, the interactions of DEP-1 and EGFR are followed by physical segregation: whereas EGFR undergoes endocytosis, DEP-1 remains confined to the cell surface. Conclusions EGFR and DEP-1 physically interact at the cell surface and maitain bidirectional enzyme-substrate interactions, which are relevant to their respective oncogenic and tumor suppressive functions. These observations highlight the emerging roles of vesicular trafficking in malignant processes. PMID:19836242

  18. Unbiased analysis of senescence associated secretory phenotype (SASP) to identify common components following different genotoxic stresses

    PubMed Central

    Özcan, Servet; Alessio, Nicola; Acar, Mustafa B.; Mert, Eda; Omerli, Fatih; Peluso, Gianfranco; Galderisi, Umberto

    2016-01-01

    Senescent cells secrete senescence-associated secretory phenotype (SASP) proteins to carry out several functions, such as sensitizing surrounding cells to senesce; immunomodulation; impairing or fostering cancer growth; and promoting tissue development. Identifying secreted factors that achieve such tasks is a challenging issue since the profile of secreted proteins depends on genotoxic stress and cell type. Currently, researchers are trying to identify common markers for SASP. The present investigation compared the secretome composition of five different senescent phenotypes in two different cell types: bone marrow and adipose mesenchymal stromal cells (MSC). We induced MSC senescence by oxidative stress, doxorubicin treatment, X-ray irradiation, and replicative exhaustion. We took advantage of LC-MS/MS proteome identification and subsequent gene ontology (GO) evaluation to perform an unbiased analysis (hypothesis free manner) of senescent secretomes. GO analysis allowed us to distribute SASP components into four classes: extracellular matrix/cytoskeleton/cell junctions; metabolic processes; ox-redox factors; and regulators of gene expression. We used Ingenuity Pathway Analysis (IPA) to determine common pathways among the different senescent phenotypes. This investigation, along with identification of eleven proteins that were exclusively expressed in all the analyzed senescent phenotypes, permitted the identification of three key signaling paths: MMP2 - TIMP2; IGFBP3 - PAI-1; and Peroxiredoxin 6 - ERP46 - PARK7 - Cathepsin D - Major vault protein. We suggest that these paths could be involved in the paracrine circuit that induces senescence in neighboring cells and may confer apoptosis resistance to senescent cells. PMID:27288264

  19. Feasibility of Unbiased RNA Profiling of Colorectal Tumors: A Proof of Principle

    PubMed Central

    Moshayoff, Vardit; Faktor, Ouriel; Laghi, Luigi; Celesti, Giuseppe; Peretz, Tamar; Keret, Dan

    2016-01-01

    Despite recent advances in molecular profiling of colorectal cancer (CRC), as of yet this has not translated into an unbiased molecular liquid biopsy profile which can accurately screen for early CRC. In this study we depict the profile of early stage CRC as well as for advanced adenomas (AA) by combination of current molecular knowledge with microarray technology, using efficient circulating free plasma RNA purification from blood and RNA amplification technologies. We joined literature search with Affymetrix gene chip experimental procedure to draw the circulating free plasma RNA profile of colorectal cancer disease reflected in blood. The RNA panel was tested by two datasets comparing patients with CRC with healthy subjects and patients with AA to healthy subjects. For the CRC patient cohort (28 CRC cases vs. 41 healthy controls), the ROC analysis of the selected biomarker panel generated a sensitivity of 75% and a specificity of 93% for the detection of CRC using 8-gene classification model. For the AA patient cohort (28 subjects vs. 46 healthy controls), a sensitivity of 60% and a specificity of 87% were calculated using a 2-gene classification model. We have identified a panel of 8 plasma RNA markers as a preliminary panel for CRC detection and subset markers suitable for AA detection. Subjected to extensive clinical validation we suggest that this panel represents a feasible approach and a potential strategy for noninvasive early diagnosis, as a first-line screening test for asymptomatic, average-risk population before colonoscopy. PMID:27441409

  20. TOWARD UNBIASED GALAXY CLUSTER MASSES FROM LINE-OF-SIGHT VELOCITY DISPERSIONS

    SciTech Connect

    Saro, Alex; Mohr, Joseph J.; Bazin, Gurvan; Dolag, Klaus

    2013-07-20

    We study the use of red-sequence-selected galaxy spectroscopy for unbiased estimation of galaxy cluster masses by using a publicly available simulated galaxy catalog. We explore the impact of selection using galaxy color, projected separation from the cluster center, galaxy luminosity, and spectroscopic redshift. We identify and characterize each of the following sources of bias and scatter in velocity dispersion at fixed mass: the intrinsic properties of halos in the form of halo triaxiality, sampling noise, the presence of multiple kinematic populations within the cluster, and the effect of interlopers. We show that even in red-sequence and spectroscopically selected galaxy samples, the interloper fraction is significant, and that the variations in the interloper population from cluster to cluster provide the dominant contribution to the velocity dispersion scatter at fixed mass. We present measurements of the total scatter in dispersion at fixed mass as a function of the number of redshifts. Results indicate that improvements in scatter are modest beyond samples of {approx}30 redshifts per cluster. Our results show that while cluster velocity dispersions extracted from a few dozen red-sequence-selected galaxies do not provide precise masses on a single cluster basis, an ensemble of cluster velocity dispersions can be combined to produce a precise calibration of a cluster survey-mass-observable relation. Currently, disagreements in the literature on simulated subhalo velocity dispersion-mass relations place a systematic floor on velocity dispersion mass calibration at the 5% level in dispersion.

  1. Asymptotically Unbiased Estimation of Exposure Odds Ratios in Complete Records Logistic Regression

    PubMed Central

    Bartlett, Jonathan W.; Harel, Ofer; Carpenter, James R.

    2015-01-01

    Missing data are a commonly occurring threat to the validity and efficiency of epidemiologic studies. Perhaps the most common approach to handling missing data is to simply drop those records with 1 or more missing values, in so-called “complete records” or “complete case” analysis. In this paper, we bring together earlier-derived yet perhaps now somewhat neglected results which show that a logistic regression complete records analysis can provide asymptotically unbiased estimates of the association of an exposure of interest with an outcome, adjusted for a number of confounders, under a surprisingly wide range of missing-data assumptions. We give detailed guidance describing how the observed data can be used to judge the plausibility of these assumptions. The results mean that in large epidemiologic studies which are affected by missing data and analyzed by logistic regression, exposure associations may be estimated without bias in a number of settings where researchers might otherwise assume that bias would occur. PMID:26429998

  2. Unbiased Stereological Analysis of Reactive Astrogliosis to Estimate Age-Associated Cerebral White Matter Injury.

    PubMed

    McNeal, David W; Brandner, Dieter D; Gong, Xi; Postupna, Nadia O; Montine, Thomas J; Keene, C Dirk; Back, Stephen A

    2016-06-01

    Cerebral white matter injury (WMI) contributes to cognitive dysfunction associated with pathological aging. Because reactive astrocyte-related factors contribute to remyelination failure after WMI, we sought accurate, cost-effective, and reproducible histopathological approaches for quantification of morphometric features of reactive astrogliosis in aged human white matter in patients with vascular brain injury (VBI). We compared 7 distinct approaches to quantify the features of glial fibrillary acidic protein (GFAP)-labeled astrocytes in the prefrontal white matter of brains from patients with VBI (n = 17, mean age 88.8 years) and controls that did not exhibit VBI (n = 11, mean age 86.6 years). Only modern stereological techniques (ie, optical fractionator and spaceballs) and virtual process thickness measurements demonstrated significant changes in astrocyte number, process length, or proximal process thickness in cases with VBI relative to controls. The widely employed methods of neuropathological scoring, antibody capture assay (histelide), area fraction fractionator, and Cavalieri point counting failed to detect significant differences in GFAP expression between the groups. Unbiased stereological approaches and virtual thickness measurements provided the only sensitive and accurate means to quantify astrocyte reactivity as a surrogate marker of WMI in human brains with VBI. PMID:27142644

  3. Unbiased quantitative proteomics of lipid rafts reveals high specificity for signaling factors

    PubMed Central

    Foster, Leonard J.; de Hoog, Carmen L.; Mann, Matthias

    2003-01-01

    Membrane lipids were once thought to be homogenously distributed in the 2D surface of a membrane, but the lipid raft theory suggests that cholesterol and sphingolipids partition away from other membrane lipids. Lipid raft theory further implicates these cholesterol-rich domains in many processes such as signaling and vesicle traffic. However, direct characterization of rafts has been difficult, because they cannot be isolated in pure form. In the first functional proteomic analysis of rafts, we use quantitative high-resolution MS to specifically detect proteins depleted from rafts by cholesterol-disrupting drugs, resulting in a set of 241 authentic lipid raft components. We detect a large proportion of signaling molecules, highly enriched versus total membranes and detergent-resistant fractions, which thus far biochemically defined rafts. Our results provide the first large-scale and unbiased evidence, to our knowledge, for the connection of rafts with signaling and place limits on the fraction of plasma membrane composed by rafts. PMID:12724530

  4. Unbiased Prediction and Feature Selection in High-Dimensional Survival Regression

    PubMed Central

    Laimighofer, Michael; Krumsiek, Jan; Theis, Fabian J.

    2016-01-01

    Abstract With widespread availability of omics profiling techniques, the analysis and interpretation of high-dimensional omics data, for example, for biomarkers, is becoming an increasingly important part of clinical medicine because such datasets constitute a promising resource for predicting survival outcomes. However, early experience has shown that biomarkers often generalize poorly. Thus, it is crucial that models are not overfitted and give accurate results with new data. In addition, reliable detection of multivariate biomarkers with high predictive power (feature selection) is of particular interest in clinical settings. We present an approach that addresses both aspects in high-dimensional survival models. Within a nested cross-validation (CV), we fit a survival model, evaluate a dataset in an unbiased fashion, and select features with the best predictive power by applying a weighted combination of CV runs. We evaluate our approach using simulated toy data, as well as three breast cancer datasets, to predict the survival of breast cancer patients after treatment. In all datasets, we achieve more reliable estimation of predictive power for unseen cases and better predictive performance compared to the standard CoxLasso model. Taken together, we present a comprehensive and flexible framework for survival models, including performance estimation, final feature selection, and final model construction. The proposed algorithm is implemented in an open source R package (SurvRank) available on CRAN. PMID:26894327

  5. The role of fire in UK peatland and moorland management: the need for informed, unbiased debate

    PubMed Central

    Davies, G. Matt; Kettridge, Nicholas; Stoof, Cathelijne R.; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M.; Marrs, Rob; Clay, Gareth D.; McMorrow, Julia; Vandvik, Vigdis

    2016-01-01

    Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216512

  6. The role of fire in UK peatland and moorland management: the need for informed, unbiased debate.

    PubMed

    Davies, G Matt; Kettridge, Nicholas; Stoof, Cathelijne R; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M; Marrs, Rob; Allen, Katherine A; Doerr, Stefan H; Clay, Gareth D; McMorrow, Julia; Vandvik, Vigdis

    2016-06-01

    Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions.This article is part of the themed issue 'The interaction of fire and mankind'. PMID:27216512

  7. Rapid and unbiased extraction of chromatin associated RNAs from purified native chromatin.

    PubMed

    Zhou, Zhongwu; Yang, Yi; Konieczny, Stephen F; Irudayaraj, Joseph M K

    2015-12-24

    An ultra fast and unbiased method that uses salicylic acid coated magnetic nanoparticles (SAMNPs) and magnetophoretic chromatography is developed to extract chromatin associated RNAs (CARs). The SAMNPs were first used for enriching cells from the cell culture media and further used for capturing chromatin after cells were lysed. The formed SAMNPs-chromatin complexes were transferred to a viscous polyethylene glycol (PEG) solution stored in a 200-μl pipette tip. Due to the difference in viscosities, a bi-layer liquid was formed inside the pipette tip. The SAMNPs-chromatin complexes were separated from the free SAMNPs and free RNA-SAMNPs complexes by applying an external magnetic field. The CARs were further extracted from the SAMNP-chromatin complexes directly. The extracted CARs were reverse transcribed as cDNA and further characterized by real-time qPCR. The total assay time taken for cell separation, chromatin purification and chromatin associated RNAs extraction can be accomplished in less than 2h. PMID:26643718

  8. Can hunting data be used to estimate unbiased population parameters? A case study on brown bears.

    PubMed

    Leclerc, Martin; Van de Walle, Joanie; Zedrosser, Andreas; Swenson, Jon E; Pelletier, Fanie

    2016-06-01

    Quantifying temporal changes in harvested populations is critical for applied and fundamental research. Unbiased data are required to detect true changes in phenotypic distribution or population size. Because of the difficulty of collecting detailed individual data from wild populations, data from hunting records are often used. Hunting records, however, may not represent a random sample of a population. We aimed to detect and quantify potential bias in hunting records. We compared data from a long-term monitoring project with hunting records of brown bears (Ursus arctos) in Sweden and investigated temporal trends (1996-2013) in the ratio of yearlings to adult females, yearling mass and adult female mass. Data from hunting records underestimated the decline in yearling and adult female mass over time, most likely owing to the legal protection of family groups from hunting, but reflected changes in the ratio of yearlings to adult females more reliably. Although hunting data can be reliable to approximate population abundance in some circumstances, hunting data can represent a biased sample of a population and should be used with caution in management and conservation decisions. PMID:27303052

  9. Can hunting data be used to estimate unbiased population parameters? A case study on brown bears

    PubMed Central

    Van de Walle, Joanie; Zedrosser, Andreas; Swenson, Jon E.; Pelletier, Fanie

    2016-01-01

    Quantifying temporal changes in harvested populations is critical for applied and fundamental research. Unbiased data are required to detect true changes in phenotypic distribution or population size. Because of the difficulty of collecting detailed individual data from wild populations, data from hunting records are often used. Hunting records, however, may not represent a random sample of a population. We aimed to detect and quantify potential bias in hunting records. We compared data from a long-term monitoring project with hunting records of brown bears (Ursus arctos) in Sweden and investigated temporal trends (1996–2013) in the ratio of yearlings to adult females, yearling mass and adult female mass. Data from hunting records underestimated the decline in yearling and adult female mass over time, most likely owing to the legal protection of family groups from hunting, but reflected changes in the ratio of yearlings to adult females more reliably. Although hunting data can be reliable to approximate population abundance in some circumstances, hunting data can represent a biased sample of a population and should be used with caution in management and conservation decisions. PMID:27303052

  10. Unbiased Prediction and Feature Selection in High-Dimensional Survival Regression.

    PubMed

    Laimighofer, Michael; Krumsiek, Jan; Buettner, Florian; Theis, Fabian J

    2016-04-01

    With widespread availability of omics profiling techniques, the analysis and interpretation of high-dimensional omics data, for example, for biomarkers, is becoming an increasingly important part of clinical medicine because such datasets constitute a promising resource for predicting survival outcomes. However, early experience has shown that biomarkers often generalize poorly. Thus, it is crucial that models are not overfitted and give accurate results with new data. In addition, reliable detection of multivariate biomarkers with high predictive power (feature selection) is of particular interest in clinical settings. We present an approach that addresses both aspects in high-dimensional survival models. Within a nested cross-validation (CV), we fit a survival model, evaluate a dataset in an unbiased fashion, and select features with the best predictive power by applying a weighted combination of CV runs. We evaluate our approach using simulated toy data, as well as three breast cancer datasets, to predict the survival of breast cancer patients after treatment. In all datasets, we achieve more reliable estimation of predictive power for unseen cases and better predictive performance compared to the standard CoxLasso model. Taken together, we present a comprehensive and flexible framework for survival models, including performance estimation, final feature selection, and final model construction. The proposed algorithm is implemented in an open source R package (SurvRank) available on CRAN. PMID:26894327

  11. Feasibility of Unbiased RNA Profiling of Colorectal Tumors: A Proof of Principle.

    PubMed

    Moshayoff, Vardit; Faktor, Ouriel; Laghi, Luigi; Celesti, Giuseppe; Peretz, Tamar; Keret, Dan; Cohen, Dana; Israeli, Eran

    2016-01-01

    Despite recent advances in molecular profiling of colorectal cancer (CRC), as of yet this has not translated into an unbiased molecular liquid biopsy profile which can accurately screen for early CRC. In this study we depict the profile of early stage CRC as well as for advanced adenomas (AA) by combination of current molecular knowledge with microarray technology, using efficient circulating free plasma RNA purification from blood and RNA amplification technologies. We joined literature search with Affymetrix gene chip experimental procedure to draw the circulating free plasma RNA profile of colorectal cancer disease reflected in blood. The RNA panel was tested by two datasets comparing patients with CRC with healthy subjects and patients with AA to healthy subjects. For the CRC patient cohort (28 CRC cases vs. 41 healthy controls), the ROC analysis of the selected biomarker panel generated a sensitivity of 75% and a specificity of 93% for the detection of CRC using 8-gene classification model. For the AA patient cohort (28 subjects vs. 46 healthy controls), a sensitivity of 60% and a specificity of 87% were calculated using a 2-gene classification model. We have identified a panel of 8 plasma RNA markers as a preliminary panel for CRC detection and subset markers suitable for AA detection. Subjected to extensive clinical validation we suggest that this panel represents a feasible approach and a potential strategy for noninvasive early diagnosis, as a first-line screening test for asymptomatic, average-risk population before colonoscopy. PMID:27441409

  12. Mutual Events in the Uranian satellite system in 2007

    NASA Astrophysics Data System (ADS)

    Arlot, J. E.

    2008-09-01

    observed "pole-on" and the relative inclinations of the orbits of the satellites are very difficult to know. More, this knowledge should allow us to determine the precession of Uranus which is not yet known. Another reason to improve the dynamics of the Uranian satellites is to quantify the dissipation of energy inside the satellites because of the tides: only very accurate astrometric observations may allow to reach such a result. We used two models for our purpose: the one from Laskar and Jacobson (GUST86) based upon observations made using observations made from 1911 to 1986 [1] and the one from Arlot, Lainey and Thuillot (LA06) [2] based upon a different sets of observations made from 1950 to 2006. Astrometric observations Since the mutual events are observable only every 42 years (in fact, 2007 was the first time where mutual events were observed on the Uranian system), many other astrometric observations were performed, mainly with photographic plates, CCD targets or using a meridian transit circle. These observations and their accuracy will be compared with mutual events. Note that these observations introduce some biases in the data (date of the opposition, absolute position of the planet), different than those of mutual events (equinox time). Observations of mutual events in 2007 Due to the difficulty of the observations, very few observations were made: about 15 events were observed using telescopes with apertures from 40 cm to 8 meters... The observing sites which reported observations were Marseille and Pic du Midi (France), Canarian Islands (Spain), La Silla and Paranal (Chile), Itajuba (Brazil), Tubitak (Turkey), Hanle (India) and Siding Spring (Australia). A preliminary analysis Some light curves were reduced and a comparison has been made with the theoretical calculations of the events. A preliminary analysis shows that LA06 has smaller residuals in the longitudes of the satellites than GUST86 but the residuals are equivalent in latitude. This confirms the

  13. 76 FR 35084 - Mutual to Stock Conversion Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ... Office of Thrift Supervision Mutual to Stock Conversion Application AGENCY: Office of Thrift Supervision... following information collection. Title of Proposal: Mutual to Stock Conversion Application. OMB Number... of all information furnished in the application in order to determine the safety and soundness of...

  14. Mutuality, Self-Silencing, and Disordered Eating in College Women

    ERIC Educational Resources Information Center

    Wechsler, Lisa S.; Riggs, Shelley A.; Stabb, Sally D.; Marshall, David M.

    2006-01-01

    The current study examined patterns of association among mutuality, self-silencing, and disordered eating in an ethnically diverse sample of college women (N = 149). Partner mutuality and overall self-silencing were negatively correlated and together were associated with six disordered eating indices. All four self-silencing subscales were…

  15. 77 FR 73115 - Mutual Savings Association Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... Office of the Comptroller of the Currency Mutual Savings Association Advisory Committee AGENCY: Office of... has determined that the renewal of the charter of the OCC Mutual Savings Association Advisory... savings associations, the regulatory changes or other steps the OCC may be able to take to ensure...

  16. 7 CFR 550.13 - Mutuality of interest.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Mutuality of interest. 550.13 Section 550.13 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT.... Mutual interest exists when both parties benefit in the same qualitative way from the objectives of...

  17. Social Climate Comparison of Mutual Help and Psychotherapy Groups.

    ERIC Educational Resources Information Center

    Toro, Paul A.; Rappaport, Julian

    In recent years, mutual help groups have been formed to address problems in substance abuse, chronic physical illness, mental illness, marital disruption, and child abuse. Despite the proliferation of these groups, little research has been conducted to assess their efficacy or what happens in them. The nature of mutual help groups (N=32) was…

  18. Use of the Mutual Exclusivity Assumption by Young Word Learners

    ERIC Educational Resources Information Center

    Markman, Ellen M.; Wasow, Judith L.; Hansen, Mikkel B.

    2003-01-01

    A critical question about early word learning is whether word learning constraints such as mutual exclusivity exist and foster early language acquisition. It is well established that children will map a novel label to a novel rather than a familiar object. Evidence for the role of mutual exclusivity in such indirect word learning has been…

  19. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Mutual capital certificates. 563.74 Section 563.74 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SAVINGS ASSOCIATIONS... having a preference or priority over an outstanding class or classes of mutual capital certificates;...

  20. Higher Education and Foster Grandparent Programs: Exploring Mutual Benefits

    ERIC Educational Resources Information Center

    Peacock, James R.; O'Quin, Jo Ann

    2006-01-01

    The purpose of this article is to highlight ways in which programs within institutions of higher education and Foster Grandparent Programs can interact to their mutual benefit. Given federal and state initiatives to develop linkages between institutions of higher education and community service sites, mutual benefits exist at the program level for…

  1. Calcium and ROS: A mutual interplay

    PubMed Central

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-01-01

    Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca2+ signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. PMID:26296072

  2. [Mutual inhibition between positive and negative emotions].

    PubMed

    Shimokawa, A

    1994-02-01

    The purpose of this study is to examine the relationship between positive and negative emotions. In study 1, 62 emotional items were selected in order to measure subjective emotional experiences. In study 2, comics, photos and poems were randomly presented to 1,220 college students to induce emotion. Subjects were asked to rate their momentary emotional intensity on two set of 5-point scales (general emotional intensity scale and 62 specific emotional intensity scale). In analysis 1, positive correlations were suggested between general emotional intensity scale and some of the specific emotional intensity scales which were activated by stimuli. In analysis 2, 10 positive and 10 negative emotional items were extracted from 62 items by factor analysis. In analysis 3, 4 and 5, it became clear that the distribution of frequency of correlations of 10 positive x 10 negative items changed according to the general emotional intensity scale. That is, from low to moderate levels of GEIS, the two kinds of emotion had no or slightly positive correlation, but at high level they became to be negatively correlated. From the facts described above, it is concluded that positive and negative emotions is not always independent, but show mutual inhibition in case of high intensity level of one of each emotions. PMID:8201808

  3. Solvation of polymers as mutual association. I. General theory

    NASA Astrophysics Data System (ADS)

    Dudowicz, Jacek; Freed, Karl F.; Douglas, Jack F.

    2013-04-01

    A Flory-Huggins (FH) type lattice theory of self-assembly is generalized to describe the equilibrium solvation of long polymer chains B by small solvent molecules A. Solvation is modeled as a thermally reversible mutual association between the polymer and a relatively low molar mass solvent. The FH Helmholtz free energy F is derived for a mixture composed of the A and B species and the various possible mutual association complexes AiB, and F is then used to generate expressions for basic thermodynamic properties of solvated polymer solutions, including the size distribution of the solvated clusters, the fraction of solvent molecules contained in solvated states (an order parameter for solvation), the specific heat (which exhibits a maximum at the solvation transition), the second and the third osmotic virial coefficients, and the boundaries for phase stability of the mixture. Special attention is devoted to the analysis of the "entropic" contribution χs to the FH interaction parameter χ of polymer solutions, both with and without associative interactions. The entropic χs parameter arises from correlations associated with polymer chain connectivity and disparities in molecular structure between the components of the mixture. Our analysis provides the first explanation of the longstanding enigma of why χs for polymer solutions significantly exceeds χs for binary polymer blends. Our calculations also reveal that χs becomes temperature dependent when interactions are strong, in sharp contrast to models currently being used for fitting thermodynamic data of associating polymer-solvent mixtures, where χs is simply assumed to be an adjustable constant based on experience with solutions of homopolymers in nonassociating solvents.

  4. UNBIASED CORRECTION RELATIONS FOR GALAXY CLUSTER PROPERTIES DERIVED FROM CHANDRA AND XMM-NEWTON

    SciTech Connect

    Zhao, Hai-Hui; Li, Cheng-Kui; Chen, Yong; Jia, Shu-Mei; Song, Li-Ming

    2015-01-20

    We use a sample of 62 clusters of galaxies to investigate the discrepancies between the gas temperature and total mass within r {sub 500} from XMM-Newton and Chandra data. Comparisons of the properties show that (1) both the de-projected and projected temperatures determined by Chandra are higher than those of XMM-Newton and there is a good linear relationship for the de-projected temperatures: T {sub Chandra} = 1.25 × T {sub XMM}–0.13. (2) The Chandra mass is much higher than the XMM-Newton mass with a bias of 0.15 and our mass relation is log{sub 10} M {sub Chandra} = 1.02 × log{sub 10} M {sub XMM}+0.15. To explore the reasons for the discrepancy in mass, we recalculate the Chandra mass (expressed as M{sub Ch}{sup mo/d}) by modifying its temperature with the de-projected temperature relation. The results show that M{sub Ch}{sup mo/d} is closer to the XMM-Newton mass with the bias reducing to 0.02. Moreover, M{sub Ch}{sup mo/d} are corrected with the r {sub 500} measured by XMM-Newton and the intrinsic scatter is significantly improved with the value reducing from 0.20 to 0.12. These mean that the temperature bias may be the main factor causing the mass bias. Finally, we find that M{sub Ch}{sup mo/d} is consistent with the corresponding XMM-Newton mass derived directly from our mass relation at a given Chandra mass. Thus, the de-projected temperature and mass relations can provide unbiased corrections for galaxy cluster properties derived from Chandra and XMM-Newton.

  5. Unbiased Characterization of Anopheles Mosquito Blood Meals by Targeted High-Throughput Sequencing.

    PubMed

    Logue, Kyle; Keven, John Bosco; Cannon, Matthew V; Reimer, Lisa; Siba, Peter; Walker, Edward D; Zimmerman, Peter A; Serre, David

    2016-03-01

    Understanding mosquito host choice is important for assessing vector competence or identifying disease reservoirs. Unfortunately, the availability of an unbiased method for comprehensively evaluating the composition of insect blood meals is very limited, as most current molecular assays only test for the presence of a few pre-selected species. These approaches also have limited ability to identify the presence of multiple mammalian hosts in a single blood meal. Here, we describe a novel high-throughput sequencing method that enables analysis of 96 mosquitoes simultaneously and provides a comprehensive and quantitative perspective on the composition of each blood meal. We validated in silico that universal primers targeting the mammalian mitochondrial 16S ribosomal RNA genes (16S rRNA) should amplify more than 95% of the mammalian 16S rRNA sequences present in the NCBI nucleotide database. We applied this method to 442 female Anopheles punctulatus s. l. mosquitoes collected in Papua New Guinea (PNG). While human (52.9%), dog (15.8%) and pig (29.2%) were the most common hosts identified in our study, we also detected DNA from mice, one marsupial species and two bat species. Our analyses also revealed that 16.3% of the mosquitoes fed on more than one host. Analysis of the human mitochondrial hypervariable region I in 102 human blood meals showed that 5 (4.9%) of the mosquitoes unambiguously fed on more than one person. Overall, analysis of PNG mosquitoes illustrates the potential of this approach to identify unsuspected hosts and characterize mixed blood meals, and shows how this approach can be adapted to evaluate inter-individual variations among human blood meals. Furthermore, this approach can be applied to any disease-transmitting arthropod and can be easily customized to investigate non-mammalian host sources. PMID:26963245

  6. A novel unbiased counting method for the quantification of synapses in the mouse brain

    PubMed Central

    Reichmann, Florian; Painsipp, Evelin; Holzer, Peter; Kummer, Daniel; Bock, Elisabeth; Leitinger, Gerd

    2015-01-01

    Background The numerical density of synapses and their ultrastructural features are best assessed with electron microscopy. Counting is done within counting frames placed on a pair of sections (disector technique). But this requires that the thin sections are taken from comparable brain regions and the disectors are placed in a uniform random fashion. Small brain areas like the polymorph layer of the mouse dentate gyrus are difficult to encounter, and manually moving the microscope stage for placing the micrographs seems arbitrary. New method Here the polymorph layer was approximated with 20 μm thin, Nissl-stained vibratome sections. The subsequent vibratome section was processed for electron microscopy and serially thin sectioned. The microscope stage was moved using a random number generator, placing at least 20 disectors onto a pair of sections. The numerical synapse density, the numerical density of dense-core vesicles, and other ultrastructural features were compared between mice that had been kept in an enriched environment and mice kept under standard housing conditions. Results Environmental enrichment significantly decreased the numerical density of dense-core vesicles and synaptic cleft widths within the polymorph layer, associated with behavioral improvement in the Morris water maze, a hippocampus-dependent task of spatial learning and memory. Comparison with existing methods This procedure was easy to handle and enabled us to produce thin sections in small, defined brain areas. Furthermore, placing the disectors with random numbers excluded observer bias. Conclusions Our procedure provides an uncomplicated way of assessing numerical densities in small brain areas in an unbiased manner. PMID:25445248

  7. A Practical Methodology to Measure Unbiased Gas Chromatographic Retention Factor vs. Temperature Relationships

    PubMed Central

    Peng, Baijie; Kuo, Mei-Yi; Yang, Panhia; Hewitt, Joshua T.; Boswell, Paul G.

    2014-01-01

    Compound identification continues to be a major challenge. Gas chromatography-mass spectrometry (GC-MS) is a primary tool used for this purpose, but the GC retention information it provides is underutilized because existing retention databases are experimentally restrictive and unreliable. A methodology called “retention projection” has the potential to overcome these limitations, but it requires the retention factor (k) vs. T relationship of a compound to calculate its retention time. Direct methods of measuring k vs. T relationships from a series of isothermal runs are tedious and time-consuming. Instead, a series of temperature programs can be used to quickly measure the k vs. T relationships, but they are generally not as accurate when measured this way because they are strongly biased by non-ideal behavior of the GC system in each of the runs. In this work, we overcome that problem by using the retention times of 25 n-alkanes to back-calculate the effective temperature profile and hold-up time vs. T profiles produced in each of six temperature programs. When the profiles were measured this way and taken into account, the k vs. T relationships measured from each of two different GC-MS instruments were nearly as accurate as the ones measured isothermally, showing less than 2-fold more error. Furthermore, temperature-programmed retention times calculated in five other labs from the new k vs. T relationships had the same distribution of error as when they were calculated from k vs. T relationships measured isothermally. Free software was developed to make the methodology easy to use. The new methodology potentially provides a relatively fast and easy way to measure unbiased k vs. T relationships. PMID:25496658

  8. Unbiased Characterization of Anopheles Mosquito Blood Meals by Targeted High-Throughput Sequencing

    PubMed Central

    Logue, Kyle; Keven, John Bosco; Cannon, Matthew V.; Reimer, Lisa; Siba, Peter; Walker, Edward D.; Zimmerman, Peter A.; Serre, David

    2016-01-01

    Understanding mosquito host choice is important for assessing vector competence or identifying disease reservoirs. Unfortunately, the availability of an unbiased method for comprehensively evaluating the composition of insect blood meals is very limited, as most current molecular assays only test for the presence of a few pre-selected species. These approaches also have limited ability to identify the presence of multiple mammalian hosts in a single blood meal. Here, we describe a novel high-throughput sequencing method that enables analysis of 96 mosquitoes simultaneously and provides a comprehensive and quantitative perspective on the composition of each blood meal. We validated in silico that universal primers targeting the mammalian mitochondrial 16S ribosomal RNA genes (16S rRNA) should amplify more than 95% of the mammalian 16S rRNA sequences present in the NCBI nucleotide database. We applied this method to 442 female Anopheles punctulatus s. l. mosquitoes collected in Papua New Guinea (PNG). While human (52.9%), dog (15.8%) and pig (29.2%) were the most common hosts identified in our study, we also detected DNA from mice, one marsupial species and two bat species. Our analyses also revealed that 16.3% of the mosquitoes fed on more than one host. Analysis of the human mitochondrial hypervariable region I in 102 human blood meals showed that 5 (4.9%) of the mosquitoes unambiguously fed on more than one person. Overall, analysis of PNG mosquitoes illustrates the potential of this approach to identify unsuspected hosts and characterize mixed blood meals, and shows how this approach can be adapted to evaluate inter-individual variations among human blood meals. Furthermore, this approach can be applied to any disease-transmitting arthropod and can be easily customized to investigate non-mammalian host sources. PMID:26963245

  9. Mutual Events in the Uranian satellite system in 2007

    NASA Astrophysics Data System (ADS)

    Arlot, J. E.

    2008-09-01

    observed "pole-on" and the relative inclinations of the orbits of the satellites are very difficult to know. More, this knowledge should allow us to determine the precession of Uranus which is not yet known. Another reason to improve the dynamics of the Uranian satellites is to quantify the dissipation of energy inside the satellites because of the tides: only very accurate astrometric observations may allow to reach such a result. We used two models for our purpose: the one from Laskar and Jacobson (GUST86) based upon observations made using observations made from 1911 to 1986 [1] and the one from Arlot, Lainey and Thuillot (LA06) [2] based upon a different sets of observations made from 1950 to 2006. Astrometric observations Since the mutual events are observable only every 42 years (in fact, 2007 was the first time where mutual events were observed on the Uranian system), many other astrometric observations were performed, mainly with photographic plates, CCD targets or using a meridian transit circle. These observations and their accuracy will be compared with mutual events. Note that these observations introduce some biases in the data (date of the opposition, absolute position of the planet), different than those of mutual events (equinox time). Observations of mutual events in 2007 Due to the difficulty of the observations, very few observations were made: about 15 events were observed using telescopes with apertures from 40 cm to 8 meters... The observing sites which reported observations were Marseille and Pic du Midi (France), Canarian Islands (Spain), La Silla and Paranal (Chile), Itajuba (Brazil), Tubitak (Turkey), Hanle (India) and Siding Spring (Australia). A preliminary analysis Some light curves were reduced and a comparison has been made with the theoretical calculations of the events. A preliminary analysis shows that LA06 has smaller residuals in the longitudes of the satellites than GUST86 but the residuals are equivalent in latitude. This confirms the

  10. Glacier Surface Monitoring by Maximizing Mutual Information

    NASA Astrophysics Data System (ADS)

    Erten, E.; Rossi, C.; Hajnsek, I.

    2012-07-01

    The contribution of Polarimetric Synthetic Aperture Radar (PolSAR) images compared with the single-channel SAR in terms of temporal scene characterization has been found and described to add valuable information in the literature. However, despite a number of recent studies focusing on single polarized glacier monitoring, the potential of polarimetry to estimate the surface velocity of glaciers has not been explored due to the complex mechanism of polarization through glacier/snow. In this paper, a new approach to the problem of monitoring glacier surface velocity is proposed by means of temporal PolSAR images, using a basic concept from information theory: Mutual Information (MI). The proposed polarimetric tracking method applies the MI to measure the statistical dependence between temporal polarimetric images, which is assumed to be maximal if the images are geometrically aligned. Since the proposed polarimetric tracking method is very powerful and general, it can be implemented into any kind of multivariate remote sensing data such as multi-spectral optical and single-channel SAR images. The proposed polarimetric tracking is then used to retrieve surface velocity of Aletsch glacier located in Switzerland and of Inyltshik glacier in Kyrgyzstan with two different SAR sensors; Envisat C-band (single polarized) and DLR airborne L-band (fully polarimetric) systems, respectively. The effect of number of channel (polarimetry) into tracking investigations demonstrated that the presence of snow, as expected, effects the location of the phase center in different polarization, such as glacier tracking with temporal HH compared to temporal VV channels. Shortly, a change in polarimetric signature of the scatterer can change the phase center, causing a question of how much of what I am observing is motion then penetration. In this paper, it is shown that considering the multi-channel SAR statistics, it is possible to optimize the separate these contributions.

  11. Mutual information between SSH and SST fields

    NASA Astrophysics Data System (ADS)

    Le goff, Clément; Chapron, Bertrand; Fablet, Ronan; Tandeo, Pierre; Autret, Emmanuelle; Ailliot, Pierre

    2015-04-01

    Mutual information between SST and SSH Investigations to relate satellite SST and SSH measurements in the Agulhas return current region are presented. In this study, we focus on the use of SSH and SST maps obtained during the year 2004, corresponding to a particularly well-sampled period for altimetry. The SST and SSH anomalies are then obtained as high-pass filtered fields, to analyze scales smaller than approximately 300km. As revealed, we clearly distinguish different regimes. During the winter months, a marked strong correlation between fields of SSH and SST anomalies is clearly revealed. During the summer months, a much lower correlation is found. Further conditioning the analysis to separate the areas of positive and negative SSH anomalies, it is then obtained, for both summer and winter periods, that aeras of negative SSH anomalies always correspond with areas of negative SST anomalies. This high correspondance also applies in winter but only for areas of positive SSH anomalies, which indeed well match with areas of positive SST anomalies. In summer, this high correspondance is lost, and areas with positive SSH anomalies do not necessarily correspond to positive SST anomalies. Accordingly, such an effect affects and weakens the overall SST/SSH correlation during the summer months. Yet, the areas of positive SSH anomalies are not fully disconnected from the areas of positive SST anomalies. For these cases, observations and results demonstrate a systematic spatial shift between them. This suggests the influence of the mixed layer depth and wind speed to control the spatial correspondance between SST and SSH anomalies, especially below regions of positive SSH anomalies. In such cases, the upper layer SST anomalies are certainly advected by the interior flow to also provide means to relate surface observations and interior dynamics.

  12. Controlled mutual quantum entity authentication using entanglement swapping

    NASA Astrophysics Data System (ADS)

    Min-Sung, Kang; Chang-Ho, Hong; Jino, Heo; Jong-In, Lim; Hyung-Jin, Yang

    2015-09-01

    In this paper, we suggest a controlled mutual quantum entity authentication protocol by which two users mutually certify each other on a quantum network using a sequence of Greenberger-Horne-Zeilinger (GHZ)-like states. Unlike existing unidirectional quantum entity authentication, our protocol enables mutual quantum entity authentication utilizing entanglement swapping; moreover, it allows the managing trusted center (TC) or trusted third party (TTP) to effectively control the certification of two users using the nature of the GHZ-like state. We will also analyze the security of the protocol and quantum channel. Project supported by the Research Foundation of Korea University.

  13. Quantum Conditional Mutual Information, Reconstructed States, and State Redistribution.

    PubMed

    Brandão, Fernando G S L; Harrow, Aram W; Oppenheim, Jonathan; Strelchuk, Sergii

    2015-07-31

    We give two strengthenings of an inequality for the quantum conditional mutual information of a tripartite quantum state recently proved by Fawzi and Renner, connecting it with the ability to reconstruct the state from its bipartite reductions. Namely, we show that the conditional mutual information is an upper bound on the regularized relative entropy distance between the quantum state and its reconstructed version. It is also an upper bound for the measured relative entropy distance of the state to its reconstructed version. The main ingredient of the proof is the fact that the conditional mutual information is the optimal quantum communication rate in the task of state redistribution. PMID:26274402

  14. Mutually connected component of networks of networks with replica nodes

    NASA Astrophysics Data System (ADS)

    Bianconi, Ginestra; Dorogovtsev, Sergey N.; Mendes, José F. F.

    2015-01-01

    We describe the emergence of the giant mutually connected component in networks of networks in which each node has a single replica node in any layer and can be interdependent only on its replica nodes in the interdependent layers. We prove that if, in these networks, all the nodes of one network (layer) are interdependent on the nodes of the same other interconnected layer, then, remarkably, the mutually connected component does not depend on the topology of the network of networks. This component coincides with the mutual component of the fully connected network of networks constructed from the same set of layers, i.e., a multiplex network.

  15. Ionic liquid mixtures--an analysis of their mutual miscibility.

    PubMed

    Omar, Salama; Lemus, Jesus; Ruiz, Elia; Ferro, Víctor R; Ortega, Juan; Palomar, Jose

    2014-03-01

    The use of ionic liquid mixtures (IL-IL mixtures) is being investigated for fine solvent properties tuning of the IL-based systems. The scarce available studies, however, evidence a wide variety of mixing behaviors (from almost ideal to strongly nonideal), depending on both the structure of the IL components and the property considered. In fact, the adequate selection of the cations and anions involved in IL-IL mixtures may ensure the absence or presence of two immiscible liquid phases. In this work, a systematic computational study of the mixing behavior of IL-IL systems is developed by means of COSMO-RS methodology. Liquid-liquid equilibrium (LLE) and excess enthalpy (H(E)) data of more than 200 binary IL-IL mixtures (including imidazolium-, pyridinium-, pyrrolidinium-, ammonium-, and phosphonium-based ILs) are calculated at different temperatures, comparing to literature data when available. The role of the interactions between unlike cations and anions on the mutual miscibility/immiscibility of IL-IL mixtures was analyzed. On the basis of proposed guidelines, a new class of immiscible IL-IL mixtures was reported, which only is formed by imidazolium-based compounds. PMID:24521179

  16. Putative linkages between below- and aboveground mutualisms during alien plant invasions.

    PubMed

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below-aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms-mycorrhizas and legume-rhizobia on one hand, and pollinators and seed dispersers on the other hand-have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below-aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  17. Unbiased isotope equilibrium factors from partial isotope exchange experiments in 3-exchange site systems

    NASA Astrophysics Data System (ADS)

    Agrinier, Pierre; Javoy, Marc

    2016-09-01

    Two methods are available in order to evaluate the equilibrium isotope fractionation factors between exchange sites or phases from partial isotope exchange experiments. The first one developed by Northrop and Clayton (1966) is designed for isotope exchanges between two exchange sites (hereafter, the N&C method), the second one from Zheng et al. (1994) is a refinement of the first one to account for a third isotope exchanging site (hereafter, the Z method). In this paper, we use a simple model of isotope kinetic exchange for a 3-exchange site system (such as hydroxysilicates where oxygen occurs as OH and non-OH groups like in muscovite, chlorite, serpentine, or water or calcite) to explore the behavior of the N&C and Z methods. We show that these two methods lead to significant biases that cannot be detected with the usual graphical tests proposed by the authors. Our model shows that biases originate because isotopes are fractionated between all these exchanging sites. Actually, we point out that the variable mobility (or exchangeability) of isotopes in and between the exchange sites only controls the amplitude of the bias, but is not essential to the production of this bias as previously suggested. Setting a priori two of the three exchange sites at isotopic equilibrium remove the bias and thus is required for future partial exchange experiments to produce accurate and unbiased extrapolated equilibrium fractionation factors. Our modeling applied to published partial oxygen isotope exchange experiments for 3-exchange site systems (the muscovite-calcite (Chacko et al., 1996), the chlorite-water (Cole and Ripley, 1998) and the serpentine-water (Saccocia et al., 2009)) shows that the extrapolated equilibrium fractionation factors (reported as 1000 ln(α)) using either the N&C or the Z methods lead to bias that may reach several δ per mil in a few cases. These problematic cases, may be because experiments were conducted at low temperature and did not reach high

  18. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  19. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... into a mutual aid agreement related to fire protection, a firefighter employed by Town A who also is a volunteer firefighter for Town B will not have his or her hours of volunteer service for Town B counted...

  20. [Community financing for health care in Africa: mutual health insurance].

    PubMed

    Richard, V

    2005-01-01

    Health care in sub-Saharan Africa is increasingly financed by direct payments from the population. Mutual health insurance plans are developing to ensure better risk sharing. However mutual health insurance cannot fully resolve all equity issues. The low resources available for contribution and the limited availability of care services especially in the public sector cannot guarantee the quality of care necessary for the development of mutual health insurance. National governments must not forget their responsibility especially for defining and ensuring basic services that must be accessible to all. Will mutual health insurance plans be a stepping-stone to universal health care coverage and can these plans be successfully implemented in the context of an informal economy? PMID:15903084

  1. Nonlinear pattern analysis of ventricular premature beats by mutual information

    NASA Technical Reports Server (NTRS)

    Osaka, M.; Saitoh, H.; Yokoshima, T.; Kishida, H.; Hayakawa, H.; Cohen, R. J.

    1997-01-01

    The frequency of ventricular premature beats (VPBs) has been related to the risk of mortality. However, little is known about the temporal pattern of occurrence of VPBs and its relationship to autonomic activity. Hence, we applied a general correlation measure, mutual information, to quantify how VPBs are generated over time. We also used mutual information to determine the correlation between VPB production and heart rate in order to evaluate effects of autonomic activity on VPB production. We examined twenty subjects with more than 3000 VPBs/day and simulated random time series of VPB occurrence. We found that mutual information values could be used to characterize quantitatively the temporal patterns of VPB generation. Our data suggest that VPB production is not random and VPBs generated with a higher value of mutual information may be more greatly affected by autonomic activity.

  2. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  3. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  4. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  5. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Application, Licensing, and Processing Rules for WCS § 27.321... Commission's rules governing the Wireless Communications Services involved. The Commission uses the general procedures in this section for processing mutually exclusive applications in the Wireless...

  6. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  7. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  8. 47 CFR 101.45 - Mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses Processing of Applications § 101.45 Mutually... fixed point-to-point microwave applications for authorization under this part will be entitled...

  9. Parasponia: a novel system for studying mutualism stability.

    PubMed

    Behm, Jocelyn E; Geurts, Rene; Kiers, E Toby

    2014-12-01

    Understanding how mutualistic interactions are stabilized in the presence of cheaters is a major question in evolutionary biology. The legume-rhizobia mutualism has become a model system for studying how plants control cheating partners. However, the generality and evolutionary origins of these control mechanisms are intensely debated. In this Opinion article, we argue that a novel system--the Parasponia-rhizobia mutualism--will significantly advance research in mutualism stability. Parasponia is the only non-legume lineage to have evolved a rhizobial symbiosis, which provides an evolutionary replicate to test how rhizobial exploitation is controlled. Evidence also suggests that this symbiosis is young. This allows studies at an earlier evolutionary stage in mutualisms, so the origin of control mechanisms can be better understood. PMID:25239777

  10. Successful network inference from time-series data using mutual information rate

    NASA Astrophysics Data System (ADS)

    Bianco-Martinez, E.; Rubido, N.; Antonopoulos, Ch. G.; Baptista, M. S.

    2016-04-01

    This work uses an information-based methodology to infer the connectivity of complex systems from observed time-series data. We first derive analytically an expression for the Mutual Information Rate (MIR), namely, the amount of information exchanged per unit of time, that can be used to estimate the MIR between two finite-length low-resolution noisy time-series, and then apply it after a proper normalization for the identification of the connectivity structure of small networks of interacting dynamical systems. In particular, we show that our methodology successfully infers the connectivity for heterogeneous networks, different time-series lengths or coupling strengths, and even in the presence of additive noise. Finally, we show that our methodology based on MIR successfully infers the connectivity of networks composed of nodes with different time-scale dynamics, where inference based on Mutual Information fails.

  11. Successful network inference from time-series data using mutual information rate.

    PubMed

    Bianco-Martinez, E; Rubido, N; Antonopoulos, Ch G; Baptista, M S

    2016-04-01

    This work uses an information-based methodology to infer the connectivity of complex systems from observed time-series data. We first derive analytically an expression for the Mutual Information Rate (MIR), namely, the amount of information exchanged per unit of time, that can be used to estimate the MIR between two finite-length low-resolution noisy time-series, and then apply it after a proper normalization for the identification of the connectivity structure of small networks of interacting dynamical systems. In particular, we show that our methodology successfully infers the connectivity for heterogeneous networks, different time-series lengths or coupling strengths, and even in the presence of additive noise. Finally, we show that our methodology based on MIR successfully infers the connectivity of networks composed of nodes with different time-scale dynamics, where inference based on Mutual Information fails. PMID:27131481

  12. "The Exchange of Ideas Was Mutual, I Have to Say": Negotiating Researcher and Teacher "Roles" in an Early Years Educators' Professional Development Programme on Inquiry-Based Mathematics and Science Learning

    ERIC Educational Resources Information Center

    Philippou, Stavroula; Papademetri-Kachrimani, Chrystalla; Louca, Loucas

    2015-01-01

    This paper explores the experiences of 14 early years educators who participated in a continuing professional development (CPD) programme coordinated by two of the paper's authors. The programme was part of a three-year research project, which aimed at introducing early childhood educators to an inquiry-based approach to mathematics and science…

  13. A new mutually reinforcing network node and link ranking algorithm

    PubMed Central

    Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

    2015-01-01

    This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity. PMID:26492958

  14. Phase-locked laser arrays through global antenna mutual coupling

    NASA Astrophysics Data System (ADS)

    Kao, Tsung-Yu; Reno, John L.; Hu, Qing

    2016-08-01

    Phase locking of an array of lasers is a highly effective method in beam shaping because it increases the output power and reduces the lasing threshold. Here, we show a conceptually novel phase-locking mechanism based on ‘antenna mutual coupling’ in which laser elements interact through far-field radiations with definite phase relations. This allows a long-range global coupling among the array elements to achieve a robust phase locking in two-dimensional laser arrays. The scheme is ideal for lasers with a deep subwavelength confined cavity, such as nanolasers, whose divergent beam patterns could be used to achieve a strong coupling among the elements in the array. We demonstrated experimentally such a scheme based on subwavelength short-cavity surface-emitting lasers at terahertz frequencies. More than 37 laser elements that span over ∼8 λo were phase locked to each other, and delivered up to 6.5 mW (in a pulsed operation) single-mode radiation at ∼3 THz, with a maximum 450 mW A–1 slope efficiency and a near-diffraction-limited beam divergence.

  15. Mutual impedance of nonplanar-skew sinusoidal dipoles

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.; Geary, N. H.

    1975-01-01

    The mutual impedance expressions for parallel dipoles in terms of sine-integrals and cosine-integrals have been published by King (1957). The investigation reported provides analogous expressions for nonparallel dipoles. The expressions presented are most useful when the monopoles are close together. The theory of moment methods shows an approach for employing the mutual impedance of filamentary sinusoidal dipoles to calculate the impedance and scattering properties of straight and bent wires with small but finite diameter.

  16. Mutual impedance of nonplanar-skew sinusoidal dipoles

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.; Geary, N. H.

    1974-01-01

    The mutual impedance of nonplanar-skew sinusoidal dipoles is presented as a summation of several exponential integrals with complex arguments. Mathematical models are developed to show the near-zone field of the sinusoidal dipole. The mutual impedance of coupled dipoles is expressed as the sum of four monopole-mobopole impedances to simplify the analysis procedure. The subroutines for solving the parameters of the dipoles are discussed.

  17. Adding biotic complexity alters the metabolic benefits of mutualism.

    PubMed

    Harcombe, William R; Betts, Alex; Shapiro, Jason W; Marx, Christopher J

    2016-08-01

    Mutualism is ubiquitous in nature and plays an integral role in most communities. To predict the eco-evolutionary dynamics of mutualism it is critical to extend classic pair-wise analysis to include additional species. We investigated the effect of adding a third species to a pair-wise mutualism in a spatially structured environment. We tested the hypotheses that selection for costly excretions in a focal population (i) decreases when an exploiter is added (ii) increases when a third mutualist is added relative to the pair-wise scenario. We assayed the selection acting on Salmonella enterica when it exchanges methionine for carbon in an obligate mutualism with an auxotrophic Escherichia coli. A third bacterium, Methylobacterium extorquens, was then added and acted either as an exploiter of the carbon or third obligate mutualist depending on the nitrogen source. In the tripartite mutualism M. extorquens provided nitrogen to the other species. Contrary to our expectations, adding an exploiter increased selection for methionine excretion in S. enterica. Conversely, selection for cooperation was lower in the tripartite mutualism relative to the pair-wise system. Genome-scale metabolic models helped identify the mechanisms underlying these changes in selection. Our results highlight the utility of connecting metabolic mechanisms and eco-evolutionary dynamics. PMID:27272242

  18. Mutuality and the social regulation of neural threat responding

    PubMed Central

    Coan, James A.; Kasle, Shelley; Jackson, Alice; Schaefer, Hillary S.; Davidson, Richard J.

    2014-01-01

    Recent studies have shown that the presence of a caring relational partner can attenuate neural responses to threat. Here we report reanalyzed data from Coan, Schaefer, and Davidson (2006), investigating the role of relational mutuality in the neural response to threat. Mutuality reflects the degree to which couple members show mutual interest in the sharing of internal feelings, thoughts, aspirations, and joys – a vital form of responsiveness in attachment relationships. We predicted that wives who were high (versus low) in perceived mutuality, and who attended the study session with their husbands, would show reduced neural threat reactivity in response to mild electric shocks. We also explored whether this effect would depend on physical contact (handholding). As predicted, we observed that higher mutuality scores corresponded with decreased neural threat responding in the right dorsolateral prefrontal cortex and supplementary motor cortex. These effects were independent of hand-holding condition. These findings suggest that higher perceived mutuality corresponds with decreased self-regulatory effort and attenuated preparatory motor activity in response to threat cues, even in the absence of direct physical contact with social resources. PMID:23547803

  19. Evaluation of the Magnetic Fields and Mutual Inductance between Circular Coils Arbitrarily Positioned in Space

    NASA Astrophysics Data System (ADS)

    Anele, A. O.; Hamam, Y.; Chassagne, L.; Linares, J.; Alayli, Y.; Djouani, K.

    2015-09-01

    This paper presents the evaluation of the magnetic fields and mutual inductance between circular coils arbitrarily positioned in space. Firstly, based on an advanced and relevant model available in the literature, MATLAB code is implemented to evaluate the mutual inductance between circular coils arbitrarily positioned with respect to each other. The computed results are compared with the numerical results previously published in the literature and a detailed clarification regarding the huge computational errors made are presented. In the second part, a complex and relevant model available in the literature for evaluating the magnetic fields due to a circular coil is presented. Based on the useful information, the model for computing the magnetic fields between two circular coils is formulated. The computed results are validated with experimental measurements. The comparison of the results shows that the developed model and the experimental measurements conducted are accurate and effective.

  20. Exploring mutuality within the nurse-patient relationship.

    PubMed

    Briant, S; Freshwater, D

    This article explores the concept of boundaries within the nurse-patient relationship. Drawing on child development theories the authors explore the difficulties of boundary maintenance and link this to the professional aspects of therapeutic alliance. The ability to establish clear boundaries between ourselves and others is closely related to the capacity to function as a healthy adult and as such may be said to play an important role in the development of mental health difficulties. However, it is generally accepted by psychological theorists that a certain amount of projection and transference are likely to occur in every two-person relationship and as a result boundary confusion is likely to be experienced by both parties to a greater or lesser extent in the nurse-patient relationship. If, as is currently asserted by the nursing profession, the nurse-patient relationship is based on the principle of equality then it follows that both the nurse and the patient carry equal responsibility for maintaining the boundaries within which their interactions take place. The authors argue that it may be more appropriate to think in terms of a relationship founded on the concept of 'mutuality'. Such a position enables the concept of therapeutic reciprocity to be embraced alongside the reality that ultimately it is the nurse who carries the responsibility for 'holding' the boundaries within which the relationship is 'acted out.' PMID:9661346

  1. Link Prediction in Weighted Networks: A Weighted Mutual Information Model

    PubMed Central

    Zhu, Boyao; Xia, Yongxiang

    2016-01-01

    The link-prediction problem is an open issue in data mining and knowledge discovery, which attracts researchers from disparate scientific communities. A wealth of methods have been proposed to deal with this problem. Among these approaches, most are applied in unweighted networks, with only a few taking the weights of links into consideration. In this paper, we present a weighted model for undirected and weighted networks based on the mutual information of local network structures, where link weights are applied to further enhance the distinguishable extent of candidate links. Empirical experiments are conducted on four weighted networks, and results show that the proposed method can provide more accurate predictions than not only traditional unweighted indices but also typical weighted indices. Furthermore, some in-depth discussions on the effects of weak ties in link prediction as well as the potential to predict link weights are also given. This work may shed light on the design of algorithms for link prediction in weighted networks. PMID:26849659

  2. Phase-locked laser array through global antenna mutual coupling

    DOE PAGESBeta

    Kao, Tsung -Yu; Reno, John L.; Hu, Qing

    2016-01-01

    Here, phase locking of an array of lasers is a highly effective way in beam shaping, to increase the output power, and to reduce lasing threshold. In this work, we present a novel phase-locking mechanism based on "antenna mutual coupling" wherein laser elements interact through far-field radiations with definite phase relations. This allows long-range global coupling among array elements to achieve robust 2-dimensional phase-locked laser array. The new scheme is ideal for lasers with deep sub-wavelength confined cavity such as nanolasers, where the divergent beam pattern could be used to form strong coupling among elements in the array. We experimentallymore » demonstrated such a scheme using sub-wavelength short-cavity surface-emitting lasers at terahertz frequency. More than 37 laser elements are phase-locked to each other, delivering up to 6.5 mW single-mode radiations at ~3 terahertz, with maximum 450-mW/A slope efficiency and near diffraction limit beam divergence.« less

  3. Image scoring and cooperation in a cleaner fish mutualism.

    PubMed

    Bshary, Redouan; Grutter, Alexandra S

    2006-06-22

    Humans are highly social animals and often help unrelated individuals that may never reciprocate the altruist's favour. This apparent evolutionary puzzle may be explained by the altruist's gain in social image: image-scoring bystanders, also known as eavesdroppers, notice the altruistic act and therefore are more likely to help the altruist in the future. Such complex indirect reciprocity based on altruistic acts may evolve only after simple indirect reciprocity has been established, which requires two steps. First, image scoring evolves when bystanders gain personal benefits from information gathered, for example, by finding cooperative partners. Second, altruistic behaviour in the presence of such bystanders may evolve if altruists benefit from access to the bystanders. Here, we provide experimental evidence for both of the requirements in a cleaning mutualism involving the cleaner fish Labroides dimidiatus. These cleaners may cooperate and remove ectoparasites from clients or they may cheat by feeding on client mucus. As mucus may be preferred over typical client ectoparasites, clients must make cleaners feed against their preference to obtain a cooperative service. We found that eavesdropping clients spent more time next to 'cooperative' than 'unknown cooperative level' cleaners, which shows that clients engage in image-scoring behaviour. Furthermore, trained cleaners learned to feed more cooperatively when in an 'image-scoring' than in a 'non-image-scoring' situation. PMID:16791194

  4. Human attribute concepts: relative ubiquity across twelve mutually isolated languages.

    PubMed

    Saucier, Gerard; Thalmayer, Amber Gayle; Bel-Bahar, Tarik S

    2014-07-01

    It has been unclear which human-attribute concepts are most universal across languages. To identify common-denominator concepts, we used dictionaries for 12 mutually isolated languages-Maasai, Supyire Senoufo, Khoekhoe, Afar, Mara Chin, Hmong, Wik-Mungkan, Enga, Fijian, Inuktitut, Hopi, and Kuna-representing diverse cultural characteristics and language families, from multiple continents. A composite list of every person-descriptive term in each lexicon was closely examined to determine the content (in terms of English translation) most ubiquitous across languages. Study 1 identified 28 single-word concepts used to describe persons in all 12 languages, as well as 41 additional terms found in 11 of 12. Results indicated that attribute concepts related to morality and competence appear to be as cross-culturally ubiquitous as basic-emotion concepts. Formulations of universal-attribute concepts from Osgood and Wierzbicka were well-supported. Study 2 compared lexically based personality models on the relative ubiquity of key associated terms, finding that 1- and 2-dimensional models draw on markedly more ubiquitous terms than do 5- or 6-factor models. We suggest that ubiquitous attributes reflect common cultural as well as common biological processes. PMID:24956320

  5. Phase-locked laser array through global antenna mutual coupling

    SciTech Connect

    Kao, Tsung -Yu; Reno, John L.; Hu, Qing

    2016-01-01

    Here, phase locking of an array of lasers is a highly effective way in beam shaping, to increase the output power, and to reduce lasing threshold. In this work, we present a novel phase-locking mechanism based on "antenna mutual coupling" wherein laser elements interact through far-field radiations with definite phase relations. This allows long-range global coupling among array elements to achieve robust 2-dimensional phase-locked laser array. The new scheme is ideal for lasers with deep sub-wavelength confined cavity such as nanolasers, where the divergent beam pattern could be used to form strong coupling among elements in the array. We experimentally demonstrated such a scheme using sub-wavelength short-cavity surface-emitting lasers at terahertz frequency. More than 37 laser elements are phase-locked to each other, delivering up to 6.5 mW single-mode radiations at ~3 terahertz, with maximum 450-mW/A slope efficiency and near diffraction limit beam divergence.

  6. The mutual shaping of life insurance and medicine in Finland.

    PubMed

    Jauho, Mikko

    2015-08-01

    This article examines the mutual shaping of medicine and private life insurance in Finland before the Second World War. Based on historical texts and archival material, it shows the important effects that the involvement of medicine in client selection for life insurance companies had on medical knowledge and practice. The analysis focuses on the tensions between the main actors in life insurance underwriting--candidates, insurance agents, examining physicians and the central office--as well as the medical examination as the key site of these tensions. The article shows how the introduction of a set of procedural and technical innovations reshaped the medical examination and helped to stabilize the fraught network of life insurance underwriting. These innovations re-scripted medical work. They stressed objective measurable knowledge over the personal skill and clinical acumen of the examining physician, propagated the physical examination and the use of diagnostic technologies and vital standards, multiplied medicine's administrative tasks, and contributed to the introduction of a risk factor approach to medicine. Moreover, the social organization of life insurance promoted the spread of these objects, practices and tasks to other fields of medicine. The case displays how medical innovations are developed through the situated interplay of multiple actors that cuts across the science-society boundary. PMID:26502657

  7. Link Prediction in Weighted Networks: A Weighted Mutual Information Model.

    PubMed

    Zhu, Boyao; Xia, Yongxiang

    2016-01-01

    The link-prediction problem is an open issue in data mining and knowledge discovery, which attracts researchers from disparate scientific communities. A wealth of methods have been proposed to deal with this problem. Among these approaches, most are applied in unweighted networks, with only a few taking the weights of links into consideration. In this paper, we present a weighted model for undirected and weighted networks based on the mutual information of local network structures, where link weights are applied to further enhance the distinguishable extent of candidate links. Empirical experiments are conducted on four weighted networks, and results show that the proposed method can provide more accurate predictions than not only traditional unweighted indices but also typical weighted indices. Furthermore, some in-depth discussions on the effects of weak ties in link prediction as well as the potential to predict link weights are also given. This work may shed light on the design of algorithms for link prediction in weighted networks. PMID:26849659

  8. Generalized approach for using unbiased symmetric metrics with negative values: normalized mean bias factor and normalized mean absolute error factor

    SciTech Connect

    Gustafson, William I.; Yu, Shaocai

    2012-10-23

    Unbiased symmetric metrics provide a useful measure to quickly compare two datasets, with similar interpretations for both under and overestimations. Two examples include the normalized mean bias factor and normalized mean absolute error factor. However, the original formulations of these metrics are only valid for datasets with positive means. This paper presents a methodology to use and interpret the metrics with datasets that have negative means. The updated formulations give identical results compared to the original formulations for the case of positive means, so researchers are encouraged to use the updated formulations going forward without introducing ambiguity.

  9. Particle infectivity of HIV-1 full-length genome infectious molecular clones in a subtype C heterosexual transmission pair following high fidelity amplification and unbiased cloning

    SciTech Connect

    Deymier, Martin J.; Claiborne, Daniel T.; Ende, Zachary; Ratner, Hannah K.; Kilembe, William; Hunter, Eric

    2014-11-15

    The high genetic diversity of HIV-1 impedes high throughput, large-scale sequencing and full-length genome cloning by common restriction enzyme based methods. Applying novel methods that employ a high-fidelity polymerase for amplification and an unbiased fusion-based cloning strategy, we have generated several HIV-1 full-length genome infectious molecular clones from an epidemiologically linked transmission pair. These clones represent the transmitted/founder virus and phylogenetically diverse non-transmitted variants from the chronically infected individual's diverse quasispecies near the time of transmission. We demonstrate that, using this approach, PCR-induced mutations in full-length clones derived from their cognate single genome amplicons are rare. Furthermore, all eight non-transmitted genomes tested produced functional virus with a range of infectivities, belying the previous assumption that a majority of circulating viruses in chronic HIV-1 infection are defective. Thus, these methods provide important tools to update protocols in molecular biology that can be universally applied to the study of human viral pathogens. - Highlights: • Our novel methodology demonstrates accurate amplification and cloning of full-length HIV-1 genomes. • A majority of plasma derived HIV variants from a chronically infected individual are infectious. • The transmitted/founder was more infectious than the majority of the variants from the chronically infected donor.

  10. Particle infectivity of HIV-1 full-length genome infectious molecular clones in a subtype C heterosexual transmission pair following high fidelity amplification and unbiased cloning

    PubMed Central

    Deymier, Martin J.; Claiborne, Daniel T.; Ende, Zachary; Ratner, Hannah K.; Kilembe, William; Allen, Susan; Hunter, Eric

    2014-01-01

    The high genetic diversity of HIV-1 impedes high throughput, large-scale sequencing and full-length genome cloning by common restriction enzyme based methods. Applying novel methods that employ a high-fidelity polymerase for amplification and an unbiased fusion-based cloning strategy, we have generated several HIV-1 full-length genome infectious molecular clones from an epidemiologically linked transmission pair. These clones represent the transmitted/founder virus and phylogenetically diverse non-transmitted variants from the chronically infected individual's diverse quasispecies near the time of transmission. We demonstrate that, using this approach, PCR-induced mutations in full-length clones derived from their cognate single genome amplicons are rare. Furthermore, all eight non-transmitted genomes tested produced functional virus with a range of infectivities, belying the previous assumption that a majority of circulating viruses in chronic HIV-1 infection are defective. Thus, these methods provide important tools to update protocols in molecular biology that could be universally applied to the study of human viral pathogens. PMID:25243334

  11. Efficient selection against categorically scored hip dysplasia in dogs is possible using best linear unbiased prediction and optimum contribution selection: a simulation study.

    PubMed

    Malm, S; Sørensen, A C; Fikse, W F; Strandberg, E

    2013-04-01

    Breeding to reduce the prevalence of categorically scored hip dysplasia (HD), based on phenotypic assessment of radiographic hip status, has had limited success. The aim of this study was to evaluate two selection strategies for improved hip status: truncation selection based on phenotypic record versus best linear unbiased prediction (BLUP), using stochastic simulation and selection scenarios resembling those in real dog populations. In addition, optimum contribution selection (OCS) was evaluated. Two traits were considered: HD (as a categorical trait with five classes and a heritability of 0.45 on the liability scale) and a continuous trait (with a heritability of 0.25) intended to represent other characteristics in the breeding goal. A population structure mimicking that in real dog populations was modelled. The categorical nature of HD caused a considerably lower genetic gain compared to simulating HD as a continuous trait. Genetic gain was larger for BLUP selection than for phenotypic selection in all scenarios. However, BLUP selection resulted in higher rates of inbreeding. By applying OCS, the rate of inbreeding was lowered to about the same level as phenotypic selection but with increased genetic improvement. For efficient selection against HD, use of BLUP breeding values should be prioritized. In small populations, BLUP should be used together with OCS or similar strategy to maintain genetic variation. PMID:23496016

  12. Exploratory study of the impacts of Mutual Health Organizations on social dynamics in Benin.

    PubMed

    Ridde, Valery; Haddad, Slim; Yacoubou, Moussa; Yacoubou, Ismaelou

    2010-08-01

    The primary aim of Mutual Health Organizations (MHOs) is the financial protection of their members. However, given their community-based, participative and voluntary nature, it is conceivable that MHOs, as social organizations, would affect social dynamics. In an exploratory study in Benin, we studied social dynamics related to mutual aid, relationships of trust, and empowerment. Four MHOs, as contrasted cases, were selected from among the 11 in the region. Focus groups (n = 20) and individual interviews (n = 29) were conducted with members, non-members, and elected leaders of the four MHOs, and with professionals from the health facilities concerned. We carried out a qualitative thematic analysis of the content. Mutual aid practices, which pre-date MHOs, can be mobilized to promote MHO membership. Mutual aid practices are based on relationships of trust. The primary reason for joining an MHO is to improve financial accessibility to health services. Non-members see that members have a strong sense of empowerment in this regard, based on a high level of trust in MHOs and their elected leaders, even if their trust in health professionals is not as strong. Non-members share these feelings of confidence in MHOs and their leadership, although they trust health professionals somewhat less than do the members. The MHOs' low penetration rate therefore cannot be explained by lack of trust, as this study shows that, even with some distrust of the professionals, the overall level of trust in MHOs is high and MHOs and their leaders function as intermediaries with health professionals. Other explanatory factors are the lack of information available to villagers and, most especially, the problems they face in being able to pay the MHO premiums. PMID:20580857

  13. Kassiopeia: a database and web application for the analysis of mutually exclusive exomes of eukaryotes

    PubMed Central

    2014-01-01

    Background Alternative splicing is an important process in higher eukaryotes that allows obtaining several transcripts from one gene. A specific case of alternative splicing is mutually exclusive splicing, in which exactly one exon out of a cluster of neighbouring exons is spliced into the mature transcript. Recently, a new algorithm for the prediction of these exons has been developed based on the preconditions that the exons of the cluster have similar lengths, sequence homology, and conserved splice sites, and that they are translated in the same reading frame. Description In this contribution we introduce Kassiopeia, a database and web application for the generation, storage, and presentation of genome-wide analyses of mutually exclusive exomes. Currently, Kassiopeia provides access to the mutually exclusive exomes of twelve Drosophila species, the thale cress Arabidopsis thaliana, the flatworm Caenorhabditis elegans, and human. Mutually exclusive spliced exons (MXEs) were predicted based on gene reconstructions from Scipio. Based on the standard prediction values, with which 83.5% of the annotated MXEs of Drosophila melanogaster were reconstructed, the exomes contain surprisingly more MXEs than previously supposed and identified. The user can search Kassiopeia using BLAST or browse the genes of each species optionally adjusting the parameters used for the prediction to reveal more divergent or only very similar exon candidates. Conclusions We developed a pipeline to predict MXEs in the genomes of several model organisms and a web interface, Kassiopeia, for their visualization. For each gene Kassiopeia provides a comprehensive gene structure scheme, the sequences and predicted secondary structures of the MXEs, and, if available, further evidence for MXE candidates from cDNA/EST data, predictions of MXEs in homologous genes of closely related species, and RNA secondary structure predictions. Kassiopeia can be accessed at http

  14. Mutuality: clinical and metapsychological potentials of a failed experiment.

    PubMed

    Castillo Mendoza, Carlos Alberto

    2012-03-01

    Ferenczi's experiments with mutual analysis are often dismissed, without acknowledging the results obtained from them and his own cautionary remarks about their limits. Though ultimately failed, Ferenczi's experiments with mutual analysis were a source of clinical and metapsychological knowledge, despite the fact that he was unable to elaborate them in his lifetime. In this paper I connect mutuality to the development of the psyche, especially to the constitutive core of the intrapsychic. To understand the latter, it is necessary to take into account, among others, issues such as the common attribute, the mutual flux between the unconsciouses, the dialogue of unconsciouses, the maternal profundity, the primal relationship with the mother, and, above all, the primal unity between mother and child, which are fundamental for the emergence and development of the primary psychic forces. Incidences of rupture, distortion of the core of mutuality in the psychic life, its loss and disadjustment, by means of external traumatizing forces, and some clinical implications are described. PMID:22398886

  15. Mutualism Disruption Threatens Global Plant Biodiversity: A Systematic Review

    PubMed Central

    Aslan, Clare E.; Zavaleta, Erika S.; Tershy, Bernie; Croll, Donald

    2013-01-01

    Background As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create “widow” species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However, the scope of this problem – the magnitude of biodiversity that may lose mutualist partners and the consequences of these losses – remains unknown. Methodology/Principal Findings We conducted a systematic review and synthesis of data from a broad range of sources to estimate the threat posed by vertebrate extinctions to the global biodiversity of vertebrate-dispersed and -pollinated plants. Though enormous research gaps persist, our analysis identified Africa, Asia, the Caribbean, and global oceanic islands as geographic regions at particular risk of disruption of these mutualisms; within these regions, percentages of plant species likely affected range from 2.1–4.5%. Widowed plants are likely to experience reproductive declines of 40–58%, potentially threatening their persistence in the context of other global change stresses. Conclusions Our systematic approach demonstrates that thousands of species may be impacted by disruption in one class of mutualisms, but extinctions will likely disrupt other mutualisms, as well. Although uncertainty is high, there is evidence that mutualism disruption directly threatens significant biodiversity in some geographic regions. Conservation measures with explicit focus on mutualistic functions could be necessary to bolster populations of widowed species and maintain ecosystem functions. PMID:23840571

  16. 26 CFR 1.822-5 - Mutual insurance company taxable income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Mutual insurance company taxable income. 1.822-5... Premium Deposits) § 1.822-5 Mutual insurance company taxable income. (a) Mutual insurance company taxable income defined. Section 822(a) defines the term “mutual insurance company taxable income” for purposes...

  17. 12 CFR 575.12 - Conversion or liquidation of mutual holding companies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Conversion or liquidation of mutual holding... MUTUAL HOLDING COMPANIES § 575.12 Conversion or liquidation of mutual holding companies. (a) Conversion—(1) Generally. A mutual holding company may convert to the stock form in accordance with the...

  18. 12 CFR 239.24 - Issuances of stock by subsidiary holding companies of mutual holding companies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... companies of mutual holding companies. 239.24 Section 239.24 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM (CONTINUED) MUTUAL HOLDING COMPANIES (REGULATION... mutual holding companies. (a) Requirements. No subsidiary holding company of a mutual holding company...

  19. 12 CFR 239.24 - Issuances of stock by subsidiary holding companies of mutual holding companies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... companies of mutual holding companies. 239.24 Section 239.24 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM (CONTINUED) MUTUAL HOLDING COMPANIES (REGULATION... mutual holding companies. (a) Requirements. No subsidiary holding company of a mutual holding company...

  20. 12 CFR 333.4 - Conversions from mutual to stock form.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... case of a savings bank subsidiary of a mutual holding company, all such plans are approved by a majority of stockholders other than its parent mutual holding company prior to implementation at a duly... insured mutual state savings banks to the mutual holding company form of ownership. As determined by...

  1. Nanoslit cavity plasmonic modes and built-in fields enhance the CW THz radiation in an unbiased antennaless photomixers array.

    PubMed

    Mohammad-Zamani, Mohammad Javad; Neshat, Mohammad; Moravvej-Farshi, Mohammad Kazem

    2016-01-15

    A new generation unbiased antennaless CW terahertz (THz) photomixer emitters array made of asymmetric metal-semiconductor-metal (MSM) gratings with a subwavelength pitch, operating in the optical near-field regime, is proposed. We take advantage of size effects in near-field optics and electrostatics to demonstrate the possibility of enhancing the THz power by 4 orders of magnitude, compared to a similar unbiased antennaless array of the same size that operates in the far-field regime. We show that, with the appropriate choice of grating parameters in such THz sources, the first plasmonic resonant cavity mode in the nanoslit between two adjacent MSMs can enhance the optical near-field absorption and, hence, the generation of photocarriers under the slit in the active medium. These photocarriers, on the other hand, are accelerated by the large built-in electric field sustained under the nanoslits by two dissimilar Schottky barriers to create the desired large THz power that is mainly radiated downward. The proposed structure can be tuned in a broadband frequency range of 0.1-3 THz, with output power increasing with frequency. PMID:26766729

  2. Identification and characterization of Highlands J virus from a Mississippi sandhill crane using unbiased next-generation sequencing

    USGS Publications Warehouse

    Ip, Hon S.; Wiley, Michael R.; Long, Renee; Gustavo, Palacios; Shearn-Bochsler, Valerie; Whitehouse, Chris A.

    2014-01-01

    Advances in massively parallel DNA sequencing platforms, commonly termed next-generation sequencing (NGS) technologies, have greatly reduced time, labor, and cost associated with DNA sequencing. Thus, NGS has become a routine tool for new viral pathogen discovery and will likely become the standard for routine laboratory diagnostics of infectious diseases in the near future. This study demonstrated the application of NGS for the rapid identification and characterization of a virus isolated from the brain of an endangered Mississippi sandhill crane. This bird was part of a population restoration effort and was found in an emaciated state several days after Hurricane Isaac passed over the refuge in Mississippi in 2012. Post-mortem examination had identified trichostrongyliasis as the possible cause of death, but because a virus with morphology consistent with a togavirus was isolated from the brain of the bird, an arboviral etiology was strongly suspected. Because individual molecular assays for several known arboviruses were negative, unbiased NGS by Illumina MiSeq was used to definitively identify and characterize the causative viral agent. Whole genome sequencing and phylogenetic analysis revealed the viral isolate to be the Highlands J virus, a known avian pathogen. This study demonstrates the use of unbiased NGS for the rapid detection and characterization of an unidentified viral pathogen and the application of this technology to wildlife disease diagnostics and conservation medicine.

  3. Mutual transformations between the P—Q, Q—P, and generalized Weyl ordering of operators

    NASA Astrophysics Data System (ADS)

    Xu, Xing-Lei; Li, Hong-Qi; Fan, Hong-Yi

    2014-03-01

    Based on the generalized Weyl quantization scheme, which relies on the generalized Wigner operator Ωk (p, q) with a real k parameter and can unify the P—Q, Q—P, and Weyl ordering of operators in k = 1, - 1, 0, respectively, we find the mutual transformations between δ(p — P)δ(q — Q), δ(q — Q)δ(p — P), and Ωk(p, q), which are, respectively, the integration kernels of the P—Q, Q—P, and generalized Weyl quantization schemes. The mutual transformations provide us with a new approach to deriving the Wigner function of quantum states. The fraktur P— and fraktur Q— ordered forms of Ωk (p, q) are also derived, which helps us to put the operators into their fraktur P— and fraktur Q— ordering, respectively.

  4. Homebirth transfers in the United States: narratives of risk, fear, and mutual accommodation.

    PubMed

    Cheyney, Melissa; Everson, Courtney; Burcher, Paul

    2014-04-01

    The purpose of this study was to explore the contested space of home-to-hospital transfers that occur during labor or in the immediate postpartum period, as a means of identifying the mechanisms that maintain philosophical and practice divides between homebirth midwives and hospital-based clinicians in the United States. Using data collected from open-ended, semistructured interviews, participant observation, and reciprocal ethnography, we identified six key themes-three from each provider type. Collectively, providers' narratives illuminate the central stressors that characterize home-to-hospital transfers, and from these, we identify three larger sociopolitical mechanisms that we argue are functioning to maintain fractured articulations at the time of transfer. These mechanisms impede efficient and mutually respectful interactions and can result in costly delays. However, they also contain the seeds of possible solutions, and thus are important starting points for developing an integrated maternity system premised on mutual accommodation and seamless articulations across all delivery locations. PMID:24598774

  5. 12-Step Interventions and Mutual Support Programs for Substance Use Disorders: An Overview

    PubMed Central

    Donovan, Dennis M.; Ingalsbe, Michelle H.; Benbow, James; Daley, Dennis C.

    2013-01-01

    Social workers and other behavioral health professionals are likely to encounter individuals with substance use disorders in a variety of practice settings outside of specialty treatment. 12-Step mutual support programs represent readily available, no cost community-based resources for such individuals; however, practitioners are often unfamiliar with such programs. The present article provides a brief overview of 12-Step programs, the positive substance use and psychosocial outcomes associated with active 12-Step involvement, and approaches ranging from ones that can be utilized by social workers in any practice setting to those developed for specialty treatment programs to facilitate engagement in 12-Step meetings and recovery activities. The goal is to familiarize social workers with 12-Step approaches so that they are better able to make informed referrals that match clients to mutual support groups that best meet the individual’s needs and maximize the likelihood of engagement and positive outcomes. PMID:23731422

  6. Spitzer Observations of Mutual Events in the Binary System (617) Patroclus-Menoetius

    NASA Astrophysics Data System (ADS)

    Mueller, Michael; Marchis, F.; Emery, J. P.; Berthier, J.; Hestroffer, D.; Harris, A.; Descamps, P.; Vachier, F.; Mottola, S.

    2007-10-01

    We report Spitzer observations of the binary Trojan system (617) Patroclus-Menoetius during two mutual events, when respectively one component shadowed and occulted the other. Observing the thermal response to mutual shadowing with spectral ( 8--33 µm) and temporal resolution allowed us to determine the system's thermal inertia in a uniquely direct way. Furthermore, our analysis provided an accurate determination of the system's size which is methodologically independent of the estimate by Berthier et al. (this session). Our results allow a more reliable estimate of the system's bulk density (the total mass was determined from the system's mutual orbit; Marchis et al., 2006; Berthier et al., this session). This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. This material is partly based upon work supported by the national Aeronautics and Space Administration issue through the Science Mission Directorate Research and Analysis Programs number NNG05GF09G.

  7. Occurrence and characteristics of mutual interference between LIDAR scanners

    NASA Astrophysics Data System (ADS)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  8. Homosexual mutuality: variation on a theme by Erik Erikson.

    PubMed

    Sohier, R

    The exploratory descriptive study described here was conducted in order to produce the initial empirical evidence to support reformulation of the theoretical construct of heterosexual mutuality (Erikson, 1975). Six persons were interviewed in depth on tape in order to locate them on one of four identity statuses constructed by Marcia (1964, 1966, 1973). The tool was modified and extended to meet the purposes of the study. The questions are directed toward illumination of conflictual moments in the life cycle when the ability to make appropriate decisions engenders character growth, and supports the personality integration of adulthood. An ability to make decisions results in personality integration. The small study provides evidence that there exists a homosexual mutuality (contrary to Erikson's position) which is no less valuable than heterosexual mutuality, and forms an equal basis for adult personality integration. PMID:3835200

  9. Thermalization of mutual information in hyperscaling violating backgrounds

    NASA Astrophysics Data System (ADS)

    Tanhayi, M. Reza

    2016-03-01

    We study certain features of scaling behaviors of the mutual information during a process of thermalization, more precisely we extend the time scaling behavior of mutual information which has been discussed in [1] to time-dependent hyperscaling violating geometries. We use the holographic description of entanglement entropy for two disjoint system consisting of two parallel strips whose widths are much larger than the separation between them. We show that during the thermalization process, the dynamical exponent plays a crucial rule in reading the general time scaling behavior of mutual information (e.g., at the pre-local-equilibration regime). It is shown that the scaling violating parameter can be employed to define an effective dimension.

  10. Accelerated evolution as a consequence of transitions to mutualism

    PubMed Central

    Lutzoni, François; Pagel, Mark

    1997-01-01

    Differential rates of nucleotide substitutions among taxa are a common observation in molecular phylogenetic studies, yet links between rates of DNA evolution and traits or behaviors of organisms have proved elusive. Likelihood ratio testing is used here for the first time to evaluate specific hypotheses that account for the induction of shifts in rates of DNA evolution. A molecular phylogenetic investigation of mutualist (lichen-forming fungi and fungi associated with liverworts) and nonmutualist fungi revealed four independent transitions to mutualism. We demonstrate a highly significant association between mutualism and increased rates of nucleotide substitutions in nuclear ribosomal DNA, and we demonstrate that a transition to mutualism preceded the rate acceleration of nuclear ribosomal DNA in these lineages. Our results suggest that the increased rate of evolution after the adoption of a mutualist lifestyle is generalized across the genome of these mutualist fungi. PMID:11038586

  11. Sparse Bayesian learning for DOA estimation with mutual coupling.

    PubMed

    Dai, Jisheng; Hu, Nan; Xu, Weichao; Chang, Chunqi

    2015-01-01

    Sparse Bayesian learning (SBL) has given renewed interest to the problem of direction-of-arrival (DOA) estimation. It is generally assumed that the measurement matrix in SBL is precisely known. Unfortunately, this assumption may be invalid in practice due to the imperfect manifold caused by unknown or misspecified mutual coupling. This paper describes a modified SBL method for joint estimation of DOAs and mutual coupling coefficients with uniform linear arrays (ULAs). Unlike the existing method that only uses stationary priors, our new approach utilizes a hierarchical form of the Student t prior to enforce the sparsity of the unknown signal more heavily. We also provide a distinct Bayesian inference for the expectation-maximization (EM) algorithm, which can update the mutual coupling coefficients more efficiently. Another difference is that our method uses an additional singular value decomposition (SVD) to reduce the computational complexity of the signal reconstruction process and the sensitivity to the measurement noise. PMID:26501284

  12. Sparse Bayesian Learning for DOA Estimation with Mutual Coupling

    PubMed Central

    Dai, Jisheng; Hu, Nan; Xu, Weichao; Chang, Chunqi

    2015-01-01

    Sparse Bayesian learning (SBL) has given renewed interest to the problem of direction-of-arrival (DOA) estimation. It is generally assumed that the measurement matrix in SBL is precisely known. Unfortunately, this assumption may be invalid in practice due to the imperfect manifold caused by unknown or misspecified mutual coupling. This paper describes a modified SBL method for joint estimation of DOAs and mutual coupling coefficients with uniform linear arrays (ULAs). Unlike the existing method that only uses stationary priors, our new approach utilizes a hierarchical form of the Student t prior to enforce the sparsity of the unknown signal more heavily. We also provide a distinct Bayesian inference for the expectation-maximization (EM) algorithm, which can update the mutual coupling coefficients more efficiently. Another difference is that our method uses an additional singular value decomposition (SVD) to reduce the computational complexity of the signal reconstruction process and the sensitivity to the measurement noise. PMID:26501284

  13. School-Based Mutual Support Groups for Parents.

    ERIC Educational Resources Information Center

    Simoni, Jane M.

    Parental involvement in schooling has been shown to bolster student performance. However, eliciting parents' participation in their children's schooling has proven to be an elusive task, particularly among parents from lower socio-economic and ethnic minority backgrounds. To encourage parent involvement in the school setting, an intervention that…

  14. Rényi generalizations of the conditional quantum mutual information

    SciTech Connect

    Berta, Mario; Seshadreesan, Kaushik P.; Wilde, Mark M.

    2015-02-15

    The conditional quantum mutual information I(A; B|C) of a tripartite state ρ{sub ABC} is an information quantity which lies at the center of many problems in quantum information theory. Three of its main properties are that it is non-negative for any tripartite state, that it decreases under local operations applied to systems A and B, and that it obeys the duality relation I(A; B|C) = I(A; B|D) for a four-party pure state on systems ABCD. The conditional mutual information also underlies the squashed entanglement, an entanglement measure that satisfies all of the axioms desired for an entanglement measure. As such, it has been an open question to find Rényi generalizations of the conditional mutual information, that would allow for a deeper understanding of the original quantity and find applications beyond the traditional memoryless setting of quantum information theory. The present paper addresses this question, by defining different α-Rényi generalizations I{sub α}(A; B|C) of the conditional mutual information, some of which we can prove converge to the conditional mutual information in the limit α → 1. Furthermore, we prove that many of these generalizations satisfy non-negativity, duality, and monotonicity with respect to local operations on one of the systems A or B (with it being left as an open question to prove that monotonicity holds with respect to local operations on both systems). The quantities defined here should find applications in quantum information theory and perhaps even in other areas of physics, but we leave this for future work. We also state a conjecture regarding the monotonicity of the Rényi conditional mutual informations defined here with respect to the Rényi parameter α. We prove that this conjecture is true in some special cases and when α is in a neighborhood of one.

  15. Interdependent networks with identical degrees of mutually dependent nodes

    NASA Astrophysics Data System (ADS)

    Buldyrev, Sergey V.; Shere, Nathaniel W.; Cwilich, Gabriel A.

    2011-01-01

    We study a problem of failure of two interdependent networks in the case of identical degrees of mutually dependent nodes. We assume that both networks (A and B) have the same number of nodes N connected by the bidirectional dependency links establishing a one-to-one correspondence between the nodes of the two networks in a such a way that the mutually dependent nodes have the same number of connectivity links; i.e., their degrees coincide. This implies that both networks have the same degree distribution P(k). We call such networks correspondently coupled networks (CCNs). We assume that the nodes in each network are randomly connected. We define the mutually connected clusters and the mutual giant component as in earlier works on randomly coupled interdependent networks and assume that only the nodes that belong to the mutual giant component remain functional. We assume that initially a 1-p fraction of nodes are randomly removed because of an attack or failure and find analytically, for an arbitrary P(k), the fraction of nodes μ(p) that belong to the mutual giant component. We find that the system undergoes a percolation transition at a certain fraction p=pc, which is always smaller than pc for randomly coupled networks with the same P(k). We also find that the system undergoes a first-order transition at pc>0 if P(k) has a finite second moment. For the case of scale-free networks with 2<λ⩽3, the transition becomes a second-order transition. Moreover, if λ<3, we find pc=0, as in percolation of a single network. For λ=3 we find an exact analytical expression for pc>0. Finally, we find that the robustness of CCN increases with the broadness of their degree distribution.

  16. The mutuality metaphor: understanding healthcare provision in NHS Scotland.

    PubMed

    Howieson, Brian

    2016-06-20

    Purpose - Better Health, Better Care Action Plan (Scottish Government, 2007) sets out how the Scottish Government intends to strengthen public ownership of the National Health Service in Scotland. The purpose of this paper is to advance extant knowledge by understanding how a state-led mutual health policy may be interpreted, and importantly, communicated. Design/methodology/approach - The definitional problem of mutuality will be discussed and analysed in terms of how it is (or perhaps should be) communicated? will be offered. Findings - It actually may be more instructive to think of, and communicate, mutuality as a metaphor to aid understanding of the openness and fluidity found in NHS Scotland. Research limitations/implications - The existence of paradox and ambiguity does not, however, negate the usefulness of the term "mutuality". Quite the opposite in fact: it is precisely by examining healthcare and its delivery through the lens of mutuality (rather than rejecting its complexity as a failure) that this amorphousness can be better appreciated. Practical implications - There is a need for more public, professional, and academic debate to explore and clarify its implementation, and how it is to be led. This must be provided whilst recognising the daily imperatives that NHS leaders must face. This would suggest, therefore, that a dual development path may help. Originality/value - Although Better Health, Better Care Action Plan was published in 2007, some eight years on there is still confusion and misunderstanding as to what mutuality in healthcare is, not only in policy and theory, but also in practice. It is hoped that this analysis will help address, in part, some of this confusion and misunderstanding. PMID:27296885

  17. Mutual neutralization in collisions of Li+ and F-

    NASA Astrophysics Data System (ADS)

    Nkambule, S. M.; Nurzia, P.; Larson, Å.

    2015-11-01

    Mutual neutralization in collisions of Li+ and F- is driven by an avoided crossing between the two lowest 1Σ+ electronic states of the LiF system. These electronic states are computed using the multi-reference configuration interaction method. We investigate how the adiabatic potential energy curves and the non-adiabatic coupling element depend on the choice of the reference configurations as well as the basis set. Using diabatic states, the total and differential cross sections for mutual neutralization are computed.

  18. Mutual exclusivity and exclusion: Converging evidence from two contrasting traditions

    PubMed Central

    Huntley, Kenneth R.; Ghezzi, Patrick M.

    1993-01-01

    Mutual exclusivity and exclusion are two terms used by cognitive psychologists and behavior analysts, respectively, to identify essentially the same phenomenon. While cognitive psychologists view mutual exclusivity in terms of a hypothesis that individuals use intuitively while acquiring language, behavior analysts regard exclusion as a derived stimulus relation that bears upon the acquisition and elaboration of verbal behavior. Each research tradition, though at odds with respect to accounting for the phenomenon, employs similar procedures to answer comparable questions. Insofar as both cognitive and behavioral psychologists are studying the same phenomenon, the ground work is established for collaboration between them. PMID:22477081

  19. Molecular insights into seed dispersal mutualisms driving plant population recruitment

    NASA Astrophysics Data System (ADS)

    García, Cristina; Grivet, Delphine

    2011-11-01

    Most plant species require mutualistic interactions with animals to fulfil their demographic cycle. In this regard frugivory (i.e., the intake of fruits by animals) enhances natural regeneration by mobilizing a large amount of seeds from source trees to deposition sites across the landscape. By doing so, frugivores move propagules, and the genotypes they harbour creating the spatial, ecological, and genetic environment under which subsequent recruitment proceeds. Recruitment patterns can be envisioned as the result of two density- and distance-dependent processes: seed dispersal and seed/seedling survival (the Janzen-Connell model). Population genetic studies add another layer of complexity for understanding the fate of dispersed propagules: the genetic relatedness among neighbouring seeds within a seed clump, a major outcome of frugivore activity, modifies their chances of germinating and surviving. Yet, we virtually ignore how the spatial distribution of maternal progenies and recruitment patterns relate with each other in frugivore-generated seed rains. Here we focus on the critical role of frugivore-mediated seed dispersal in shaping the spatial distribution of maternal progenies in the seed rain. We first examine which genetic mechanisms underlying recruitment are influenced by the spatial distribution of maternal progenies. Next, we examine those studies depicting the spatial distribution of maternal progenies in a frugivore-generated seed rain. In doing so, we briefly review the most suitable analytical approaches applied to track the contribution of fruiting trees to the seed rain based on molecular data. Then we look more specifically at the role of distinct frugivore guilds in determining maternal genetic correlations and their expected consequences for recruitment patterns. Finally we posit some general conclusions and suggest future research directions that would provide a more comprehensive understanding of the ecological and evolutionary consequences

  20. Mutualism in a Reduced Gravity Environment (MuRGE)

    NASA Technical Reports Server (NTRS)

    Haire, Timothy C.

    2010-01-01

    Mutualism in a Reduced Gravity Environment (MuRGE) is a ground research study to determine the feasibility of assessing fungi-plant (Piriformospora indica-Arabidopsis thaliana) interactions in microgravity. Seeds from the plant Arabiddospsis thaliana (At) will be grown in the presence of Piriformospora indica (Pi) an endophytic Sebacinacae family fungus. Pi is capable of colonizing the roots of a wide variety of plant species, including non-mycorrhizal hosts like At, and promoting plant growth similarly to AMF (arbusuclar mychorrizal fungi) unlike most AMF, Pi is not an obligate plant symbiont and can be grown in the absence of a host. In the presence of a suitable plant host, Pi can attach to and colonize root tips. Interaction visualization is accomplished with strong autofluorescence in the roots, followed by root colonization via fungal hyphae, and chlamydospore production. Increased root growth can be observed even before root colonization is detectable. In addition, Pi chlamydospores generated from axenic culture in microgravity will be used to inoculate roots of At grown in 1g to determine the effect of microgravity upon the inherent virulence or beneficial effects. Based on recent reports of increased virulence of S. typhimurium, P. aeruginosa, and S. Pneumoniae in reduced gravity, differences in microbial pathogenic responses and host plant systemic acquired resistance are expected. The focus of this project within MuRGE involved the development P. indica culture media evaluation and microscopy protocol development. High, clean spore harvest yields for the detection of fungi-plant interactions microscopically was the immediate goal of this experiment.

  1. Mental health nurses and qualitative research methods: a mutual attraction?

    PubMed

    Cutcliffe, J R; Goward, P

    2000-03-01

    Mental health nurses and qualitative research methods: a mutual attraction? In response to issues arising out of curriculum developments, the authors wished to examine more closely the potential reasons why psychiatric/mental health (P/MH) nurses appear to gravitate towards certain research methodologies. This paper therefore briefly examines the essential differences between qualitative and quantitative research paradigms, focusing on philosophical, epistemological and methodological issues. It then proceeds to examine some of the essential characteristics and attributes of P/MH nurses and suggests some differences in emphasis between these and other disciplines of nursing. The authors posit that psychiatric/mental health nurses are drawn to the qualitative paradigm as a result of the potential synchronicity and linkage that appears to exist between the practice of mental health nursing and qualitative research. This apparent synchronicity appears to centre around the three themes of: (a) the purposeful use of self; (b) the creation of an interpersonal relationship; and (c) the ability to accept and embrace ambiguity and uncertainty. Given this alleged synchronicity the authors argue that there are implications for nurse education and nursing research. Further it is possible that each nursing situation where the mental health nurse forms a relationship and attempts to gain an empathic sense of the individual's world is akin to an informal phenomenological study, the product of which would be a wealth of qualitative data. However, as this would be a subconscious, implicit process, the data would remain predominantly unprocessed. The authors conclude that perhaps these data are the knowledge that expert practitioners draw upon when making intuition-based clinical judgements. PMID:10718878

  2. Putative linkages between below- and aboveground mutualisms during alien plant invasions

    PubMed Central

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below–aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms—mycorrhizas and legume–rhizobia on one hand, and pollinators and seed dispersers on the other hand—have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below–aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  3. Influence of mutual coupling between ICRH antenna straps on the load resilience of hybrid couplers

    SciTech Connect

    Lamalle, P. U.; Messiaen, A.

    2007-09-28

    The mutual coupling present between ICRF antenna straps can strongly reduce the performance of quadrature hybrid couplers when used as 'ELM dump' circuits. An analytical study of this effect shows that during resistive ELM-like load perturbations of a matched circuit configuration, the fraction of the reflected power returned to the generator through the hybrid has a lower bound that rapidly increases with the ratio {xi}{approx} (mutual reactance between straps)/(strap input resistance). At very low levels of mutual the reflected power is efficiently diverted to the dummy load. However when {xi} becomes of order 1, which readily occurs at low resistive loading, the load resilience of the quadrature hybrid coupler becomes inhibited. Illustrations based on matching circuit simulations for the JET ITER-like ICRF antenna are presented. The behaviour of the hybrids is found the same with the load resilient 'conjugate T' circuit as in the case of 'classic' tuners. The insertion of decoupling circuits between the tuners and the antenna significantly improves the load resilience.

  4. Technique for Extension of Small Antenna Array Mutual-Coupling Data to Larger Antenna Arrays

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.

    1996-01-01

    A technique is presented whereby the mutual interaction between a small number of elements in a planar array can be interpolated and extrapolated to accurately predict the combined interactions in a much larger array of many elements. An approximate series expression is developed, based upon knowledge of the analytical characteristic behavior of the mutual admittance between small aperture antenna elements in a conducting ground plane. This expression is utilized to analytically extend known values for a few spacings and orientations to other element configurations, thus eliminating the need to numerically integrate a large number of highly oscillating and slowly converging functions. This paper shows that the technique can predict very accurately the mutual coupling between elements in a very large planar array with a knowledge of the self-admittance of an isolated element and the coupling between only two-elements arranged in eight different pair combinations. These eight pair combinations do not necessarily have to correspond to pairs in the large array, although all of the individual elements must be identical.

  5. Toward mutual support: a task analysis of the relational justice approach to infidelity.

    PubMed

    Williams, Kirstee; Galick, Aimee; Knudson-Martin, Carmen; Huenergardt, Douglas

    2013-07-01

    Gender, culture, and power issues are intrinsic to the etiology of infidelity, but the clinical literature offers little guidance on how to work with these concerns. The Relational Justice Approach (RJA) to infidelity (Williams, Family Process, 2011, 50, 516) uniquely places gender and power issues at the heart of clinical change; however, this approach has not been systematically studied. Therefore a qualitative task analysis was utilized to understand how change occurs in RJA. The findings indicated four necessary tasks: (a) creating an equitable foundation for healing, (b) creating space for alternate gender discourse, (c) pursuing relational responsibility of powerful partner, and (d) new experience of mutual support. Therapists' attention to power dynamics that organize couple relationships, leadership in intervening in power processes, and socio-cultural attunement to gender discourses were foundational to this work. These findings help clarify the processes by which mutual healing from the trauma of infidelity may occur and offer empirically based actions that therapists can take to facilitate mutual support. PMID:25059297

  6. One-sided and mutually aggressive couples: Differences in attachment, conflict prevalence, and coping.

    PubMed

    Burk, William J; Seiffge-Krenke, Inge

    2015-12-01

    This study investigated concurrent links between adolescent romantic couples' reports of aggression (relational and physical) and relationship functioning (e.g., attachment security, conflict prevalence, coping strategies, jealousy, and affiliative and romantic relationship quality) using a pattern-oriented approach. The sample included 194 romantic partner dyads (Mage=16.99 years for females and Mage=18.41 years for males). A hierarchical cluster analysis identified five distinct subgroups of dyads based on male and female reports of relational and physical aggression, ranging from nonaggressive couples (42%), to those characterized by aggressive females (18%), aggressive males (14%), physically aggressive females (20%), and mutually aggressive females and males (6%). Clusters in which one partner was perceived as either relationally or physically aggressive were characterized by higher rates of conflict, less adaptive coping, and more jealousy (particularly in males). The mutually aggressive couples showed the least adaptive relationship functioning, with high rates of conflict, a deficit in reflection and emotion regulation in conflict situations, and a lack of affiliative relationship qualities. The discussion focuses on the formative character of aggression in these early romantic relations, the aggravating impact of mutual aggression on relationship functioning, and the gender-specific functions of aggression in relationships characterized by unilateral aggression. PMID:26360706

  7. Directions of arrival estimation with planar antenna arrays in the presence of mutual coupling

    NASA Astrophysics Data System (ADS)

    Akkar, Salem; Harabi, Ferid; Gharsallah, Ali

    2013-06-01

    Directions of arrival (DoAs) estimation of multiple sources using an antenna array is a challenging topic in wireless communication. The DoAs estimation accuracy depends not only on the selected technique and algorithm, but also on the geometrical configuration of the antenna array used during the estimation. In this article the robustness of common planar antenna arrays against unaccounted mutual coupling is examined and their DoAs estimation capabilities are compared and analysed through computer simulations using the well-known MUltiple SIgnal Classification (MUSIC) algorithm. Our analysis is based on an electromagnetic concept to calculate an approximation of the impedance matrices that define the mutual coupling matrix (MCM). Furthermore, a CRB analysis is presented and used as an asymptotic performance benchmark of the studied antenna arrays. The impact of the studied antenna arrays geometry on the MCM structure is also investigated. Simulation results show that the UCCA has more robustness against unaccounted mutual coupling and performs better results than both UCA and URA geometries. The performed simulations confirm also that, although the UCCA achieves better performance under complicated scenarios, the URA shows better asymptotic (CRB) behaviour which promises more accuracy on DoAs estimation.

  8. Conditional mutual inclusive information enables accurate quantification of associations in gene regulatory networks.

    PubMed

    Zhang, Xiujun; Zhao, Juan; Hao, Jin-Kao; Zhao, Xing-Ming; Chen, Luonan

    2015-03-11

    Mutual information (MI), a quantity describing the nonlinear dependence between two random variables, has been widely used to construct gene regulatory networks (GRNs). Despite its good performance, MI cannot separate the direct regulations from indirect ones among genes. Although the conditional mutual information (CMI) is able to identify the direct regulations, it generally underestimates the regulation strength, i.e. it may result in false negatives when inferring gene regulations. In this work, to overcome the problems, we propose a novel concept, namely conditional mutual inclusive information (CMI2), to describe the regulations between genes. Furthermore, with CMI2, we develop a new approach, namely CMI2NI (CMI2-based network inference), for reverse-engineering GRNs. In CMI2NI, CMI2 is used to quantify the mutual information between two genes given a third one through calculating the Kullback-Leibler divergence between the postulated distributions of including and excluding the edge between the two genes. The benchmark results on the GRNs from DREAM challenge as well as the SOS DNA repair network in Escherichia coli demonstrate the superior performance of CMI2NI. Specifically, even for gene expression data with small sample size, CMI2NI can not only infer the correct topology of the regulation networks but also accurately quantify the regulation strength between genes. As a case study, CMI2NI was also used to reconstruct cancer-specific GRNs using gene expression data from The Cancer Genome Atlas (TCGA). CMI2NI is freely accessible at http://www.comp-sysbio.org/cmi2ni. PMID:25539927

  9. Conditional mutual inclusive information enables accurate quantification of associations in gene regulatory networks

    PubMed Central

    Zhang, Xiujun; Zhao, Juan; Hao, Jin-Kao; Zhao, Xing-Ming; Chen, Luonan

    2015-01-01

    Mutual information (MI), a quantity describing the nonlinear dependence between two random variables, has been widely used to construct gene regulatory networks (GRNs). Despite its good performance, MI cannot separate the direct regulations from indirect ones among genes. Although the conditional mutual information (CMI) is able to identify the direct regulations, it generally underestimates the regulation strength, i.e. it may result in false negatives when inferring gene regulations. In this work, to overcome the problems, we propose a novel concept, namely conditional mutual inclusive information (CMI2), to describe the regulations between genes. Furthermore, with CMI2, we develop a new approach, namely CMI2NI (CMI2-based network inference), for reverse-engineering GRNs. In CMI2NI, CMI2 is used to quantify the mutual information between two genes given a third one through calculating the Kullback–Leibler divergence between the postulated distributions of including and excluding the edge between the two genes. The benchmark results on the GRNs from DREAM challenge as well as the SOS DNA repair network in Escherichia coli demonstrate the superior performance of CMI2NI. Specifically, even for gene expression data with small sample size, CMI2NI can not only infer the correct topology of the regulation networks but also accurately quantify the regulation strength between genes. As a case study, CMI2NI was also used to reconstruct cancer-specific GRNs using gene expression data from The Cancer Genome Atlas (TCGA). CMI2NI is freely accessible at http://www.comp-sysbio.org/cmi2ni. PMID:25539927

  10. Mutual Events of the Uranian Satellites Observed with the Faulkes Telescopes

    NASA Astrophysics Data System (ADS)

    Christou, Apostolos; Lewis, F.; Hidas, M. G.; Brown, T. M.; Roche, P.

    2008-09-01

    The 2007 Uranian Equinox allowed unique observations of the planet, its rings and satellites, possible only twice during the planet's 84 year orbit. Among these were mutual eclipses and occultations between the 5 classical satellites Ariel, Umbriel, Titania, Oberon and Miranda. These ``mutual'' events are extremely useful as reality checks of satellite ephemerides. In addition, they provide an opportunity to improve our knowledge of the satellite orbits and the system constants. We observed several mutual events in 2007 using the 2m Faulkes Telescopes North (FTN) and South (FTS) located in Haleakala, Maui and Siding Spring, Australia respectively, operated by the Las Cumbres Observatory Global Telescope (LCOGT) network. To mitigate against Uranus' glare, we utilized wide-band imaging in the near-IR, a small image scale and a posteriori subtraction of the planet's PSF. We obtained positive detections of six mutual events, three occultations and three eclipses, among these satellites. Three of these events involved Miranda, a difficult target due to its proximity to Uranus. Furthermore, we recorded at least two events that were predicted to occur with high confidence but did not, in fact, occur. During this presentation we will describe our observing strategy, operational setup and data reduction techniques and present examples of obtained lightcurves. Our observational results have been compared with predictions based on ephemerides by Laskar and Jacobson (1987; GUST86), by Lainey and Arlot (2006; LA06) and by Rush and Jacobson (2007; RJ07). Offsets with respect to the Voyager-era GUST86 are quite significant, of the order of minutes in the event midtimes. Smaller, yet significant trends in the data also appear with respect to LA06 and RJ07. We will discuss the nature of these trends and how they can be interpreted in terms of potential improvements in our knowledge of the Uranian system.

  11. An Observing Campaign of the Mutual Events Within (617) Patroclus-Menoetius Binary Trojan System

    NASA Astrophysics Data System (ADS)

    Berthier, Jerome; Marchis, F.; Descamps, P.; Assafin, M.; Bouley, S.; Colas, F.; Dubos, G.; Emery, J. P.; De Cat, P.; Farrell, J. A.; Leroy, A.; Pauwels, T.; Pollock, J. T.; Reddy, V.; Sada, P. V.; Vingerhoets, P.; Vachier, F.; Vieira-Martins, R.; Wong, M. H.; Reichart, D. E.; Ivarsen, K. M.; Crain, J. A.; LaCluyze, A. P.; Nysewander, M. C.

    2007-10-01

    In 2006-2007, the binary Trojan system (617) Patroclus-Menotius reached one of its annual equinoxes. As a consequence, the system underwent a 6 months season of mutual eclipses and occultations. We organized a campaign of observations of these mutual events mostly centered along the first semester of 2007. We took advantage of an orbit solution of the similary-sized binary system published by Marchis et al. (Nature, 2006) to predict the timing of mutual eclipses and occultations observable from January to July 2007. During the campaign, the magnitude of Patroclus system varied from 15.8 to 16.6 and its solar phase from 9°.5 to 2°.7 at opposition (end of March). The amplitude of the events ranged between 0.2 and 0.3 magnitude. A large number of stations around the world were involved in the campaign and 20 lightcurves with mutual events signature were collected (http://www.imcce.fr/page.php?nav=en/observateur/campagnes_obs/patroclus/). With such favorable circumstances, photometric observations of the events will provide tight constraints regarding physical properties of the system such as sizes, shapes, sidereal spin period and surface composition. Combining AO observations collected at Keck and Gemini with this lightcurve data, we have refined the orbital parameters of the binary system to an unprecedented accuracy. We will present these findings, the determination of the sizes and shapes, and other results from the data analysis. This material is partly based upon work supported by the National Aeronautics and Space Administration issue through the Science Mission Directorate Research and Analysis Programs number NNG05GF09G.

  12. Control in mutualisms: combined implications of partner choice and bargaining roles.

    PubMed

    Golubski, Antonio J; Klausmeier, Christopher A

    2010-12-21

    When two species form a mutualistic association, the degree of control that each has over the interaction may be pivotal in determining the relative benefit each obtains. We incorporate the capacity for partner choice into a model of mutualism based on the exchange of goods and/or services, where one guild of mutualists plays the role of proposer (proposing a price at which the goods and/or services will be exchanged) and the other plays the role of responder (accepting or rejecting the deal). We show how the payoff structure in this scenario and other closely related ones correspond to the ultimatum and demand games of economics. In the model, there are both costs and benefits to a guild whose players have control over interactions. Control over interactions in the sense of being able to exercise partner choice can benefit a guild by selecting for mutualism in its partners, but is most effective in selecting against moderately exploitative partners, and so can give highly exploitative partners an advantage. This can generate dynamics similar to taxon cycles or those seen in models with competition-colonization tradeoffs, wherein increasingly more mutualistic partners (acting as superior competitors) are selected for up to a tipping point, at which highly exploitative strategies (akin to superior colonizers) gain an advantage. Control over interactions in the sense of being able to appropriate 'surplus' payoffs in each interaction, which is selected for within-guild and is equivalent to playing the role of responders, selects against high demands (and so for mutualism) in the guild with control. Combining the two mechanisms, a high degree of mutualism in both guilds and coexistence of more mutualistic and more exploitative strategies within each are both consistent with control over the interaction being highly skewed toward one side that does what is in its own short-term interests. PMID:20869371

  13. Spatially weighted mutual information image registration for image guided radiation therapy

    SciTech Connect

    Park, Samuel B.; Rhee, Frank C.; Monroe, James I.; Sohn, Jason W.

    2010-09-15

    Purpose: To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application for image guided radiation therapy (IGRT). Methods: It is well known that rigid-body image registration with mutual information is dependent on the size and location of the image subset on which the alignment analysis is based [the designated region of interest (ROI)]. Therefore, careful review and manual adjustments of the resulting registration are frequently necessary. Although there were some investigations of weighted mutual information (WMI), these efforts could not apply the differential importance to a particular spatial location since WMI only applies the weight to the joint histogram space. The authors developed the spatially weighted mutual information (SWMI) metric by incorporating an adaptable weight function with spatial localization into mutual information. SWMI enables the user to apply the selected transform to medically ''important'' areas such as tumors and critical structures, so SWMI is neither dominated by, nor neglects the neighboring structures. Since SWMI can be utilized with any weight function form, the authors presented two examples of weight functions for IGRT application: A Gaussian-shaped weight function (GW) applied to a user-defined location and a structures-of-interest (SOI) based weight function. An image registration example using a synthesized 2D image is presented to illustrate the efficacy of SWMI. The convergence and feasibility of the registration method as applied to clinical imaging is illustrated by fusing a prostate treatment planning CT with a clinical cone beam CT (CBCT) image set acquired for patient alignment. Forty-one trials are run to test the speed of convergence. The authors also applied SWMI registration using two types of weight functions to two head and neck cases and a prostate case with clinically acquired CBCT/MVCT image sets. The

  14. Mutual Interactions between Aquaporins and Membrane Components.

    PubMed

    Martínez-Ballesta, Maria Del Carmen; Carvajal, Micaela

    2016-01-01

    In recent years, a number of studies have been focused on the structural evaluation of protein complexes in order to get mechanistic insights into how proteins communicate at the molecular level within the cell. Specific sites of protein-aquaporin interaction have been evaluated and new forms of regulation of aquaporins described, based on these associations. Heterotetramerizations of aquaporin isoforms are considered as novel regulatory mechanisms for plasma membrane (PIPs) and tonoplast (TIPs) proteins, influencing their intrinsic permeability and trafficking dynamics in the adaptive response to changing environmental conditions. However, protein-protein interaction is an extensive theme that is difficult to tackle and new methodologies are being used to study the physical interactions involved. Bimolecular fluorescence complementation and the identification of cross-linked peptides based on tandem mass spectra, that are complementary to other methodologies such as heterologous expression, co-precipitation assays or confocal fluorescence microscopy, are discussed in this review. The chemical composition and the physical characteristics of the lipid bilayer also influence many aspects of membrane aquaporins, including their functionality. The molecular driving forces stabilizing the positions of the lipids around aquaporins could define their activity, thereby altering the conformational properties. Therefore, an integrative approach to the relevance of the membrane-aquaporin interaction to different processes related to plant cell physiology is provided. Finally, it is described how the interactions between aquaporins and copolymer matrixes or biological compounds offer an opportunity for the functional incorporation of aquaporins into new biotechnological advances. PMID:27625676

  15. Mutual Interactions between Aquaporins and Membrane Components

    PubMed Central

    Martínez-Ballesta, Maria del Carmen; Carvajal, Micaela

    2016-01-01

    In recent years, a number of studies have been focused on the structural evaluation of protein complexes in order to get mechanistic insights into how proteins communicate at the molecular level within the cell. Specific sites of protein-aquaporin interaction have been evaluated and new forms of regulation of aquaporins described, based on these associations. Heterotetramerizations of aquaporin isoforms are considered as novel regulatory mechanisms for plasma membrane (PIPs) and tonoplast (TIPs) proteins, influencing their intrinsic permeability and trafficking dynamics in the adaptive response to changing environmental conditions. However, protein–protein interaction is an extensive theme that is difficult to tackle and new methodologies are being used to study the physical interactions involved. Bimolecular fluorescence complementation and the identification of cross-linked peptides based on tandem mass spectra, that are complementary to other methodologies such as heterologous expression, co-precipitation assays or confocal fluorescence microscopy, are discussed in this review. The chemical composition and the physical characteristics of the lipid bilayer also influence many aspects of membrane aquaporins, including their functionality. The molecular driving forces stabilizing the positions of the lipids around aquaporins could define their activity, thereby altering the conformational properties. Therefore, an integrative approach to the relevance of the membrane-aquaporin interaction to different processes related to plant cell physiology is provided. Finally, it is described how the interactions between aquaporins and copolymer matrixes or biological compounds offer an opportunity for the functional incorporation of aquaporins into new biotechnological advances. PMID:27625676

  16. Mutual Suppression: Comment on Paulhus et Al. (2004)

    ERIC Educational Resources Information Center

    Nickerson, Carol

    2008-01-01

    Paulhus, Robins, Trzesniewski, and Tracy ("Multivariate Behavioral Research," 2004, 39, 305-328) suggested that the three types of two-predictor suppression situations--classical suppression, cooperative suppression, and net suppression--can all be considered special cases of mutual suppression, in that the magnitude of each of the two…

  17. The subtraction of mutually displaced Gaussian Schell-model beams

    NASA Astrophysics Data System (ADS)

    de Sande, J. Carlos G.; Santarsiero, Massimo; Piquero, Gemma; Gori, Franco

    2015-12-01

    Using recently derived results about the difference of two cross-spectral densities, we consider a source whose correlation function is the difference of two mutually displaced Gaussian Schell-model cross-spectral densities. We examine the main features of this new cross-spectral density in terms of coherence and intensity distribution, both across the source plane and after free propagation.

  18. No effect of diffraction on Pluto-Charon mutual events

    NASA Technical Reports Server (NTRS)

    Tholen, D. J.; Hubbard, W. B.

    1988-01-01

    Mulholland and Gustafson (1987) made the interesting suggestion that observations of Pluto-Charon mutual events might show significant dependence on both wavelength and telescope aperture because of diffraction effects. In this letter, observations are presented that show the predicted effects to be absent and demonstrate that the parameters of the system are such that the events can be accurately analyzed with geometrical optics.

  19. Circumstances for Pluto-Charon mutual events in 1989

    NASA Technical Reports Server (NTRS)

    Tholen, David J.; Buie, Marc W.

    1988-01-01

    Circumstances for 90 Pluto-Charon mutual events occurring during the 1989 opposition are presented. It is found that the deepest and longest events will occur near postopposition quadrature in early August. Two new stars are selected as comparison stars for events occurring before opposition in 1989, and it is noted that the 1988 comparison stars should be used for events occurring after opposition.

  20. The Effects of Perceived Mutual Understanding in Interpersonal Communication.

    ERIC Educational Resources Information Center

    Gordon, Ron

    To investigate the effects of mutual perceived understanding on the communicators, 86 undergraduate students in a speech communication course were asked to use a 382 item checklist to identify those feelings and sensations that described their own experiences of intense communication. Analysis of subjects' responses showed that 63 items were…

  1. 76 FR 20459 - Mutual to Stock Conversion Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... Office of Thrift Supervision Mutual to Stock Conversion Application AGENCY: Office of Thrift Supervision... Paperwork Reduction Act of 1995, 44 U.S.C. 3507. The Office of Thrift Supervision within the Department of... Thrift Supervision, 1700 G Street, NW., Washington, DC 20552; send a facsimile transmission to (202)...

  2. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... capital requirements under part 167 of this chapter if a Federal savings association or 12 CFR part 390... a Federal savings association or 12 CFR part 390, subpart Z if a state savings association; And... parity with another class of mutual capital certificates; or (F) Action is sought which would...

  3. A Swedish Mutual Support Society of Problem Gamblers

    ERIC Educational Resources Information Center

    Binde, Per

    2012-01-01

    Mutual support societies for problem gamblers have existed in Sweden for 20 years. They have helped more people with gambling problems than any other institution inside or outside the Swedish health care system. This paper outlines the background of these societies and describes the meetings of one of them. Data come from interviews with members…

  4. Mutually Beneficial Collective Bargaining in a Community College.

    ERIC Educational Resources Information Center

    Steiner, Stuart

    Collective bargaining is a bilateral decision-making process where representatives of the faculty and of the college must come to some mutual agreement on items that are listed in the body of the contract. Typically, the adversarial or competitive bargaining approach is used to resolve differences between the two sides, but there are some mutually…

  5. Mutual Intercultural Relations among University Students in Canada

    ERIC Educational Resources Information Center

    Gui, Yongxia; Safdar, Saba; Berry, John

    2016-01-01

    The current study examies the views of both international and domestic students in Canada using the conceptual and empirical framework from the MIRIPS (Mutual Intercultural Relations in Plural Societies) project (http://www.victoria.ac.nz/cacr/research/mirips). Two hypotheses were examined. First is the "multiculturalism hypothesis"…

  6. Conflict Management: A Premarital Training Program in Mutual Problem Solving.

    ERIC Educational Resources Information Center

    Ridley, Carl A.; And Others

    1981-01-01

    Evaluated the effectiveness of a structured educational program to train premarital couples in communication and mutual problem-solving skills. Couples (N=26) participated in a problem-solving training program, while similar couples (N=28) participated in a relationship discussion group. The problem-solving group showed a greater increase in…

  7. The Mutual Influence of Parenting and Boys' Externalizing Behavior Problems

    ERIC Educational Resources Information Center

    Fite, Paula J.; Colder, Craig R.; Lochman, John E.; Wells, Karen C.

    2006-01-01

    The current study examined the mutual influence of parenting and boys' externalizing behavior from 4th to 8th grade, how these relationships change as children develop, and the stability of parenting and child behavior in a sample of 122 boys. Child behavior predicted poor parental monitoring at 6th and 7th grade and inconsistent discipline at all…

  8. Mutual Aid: A Key to Survival for Black Americans

    ERIC Educational Resources Information Center

    Norman, Alex J.

    1977-01-01

    In the Brotherhood Crusade, a black mutual aid, self-help organization, Los Angeles blacks joined together to effect independence within the professions and the social service delivery systems, rejecting incorporation into the United Way, the major L.A. fund-raising organization. This article presents findings of a study of Crusade participants.…

  9. 77 FR 48566 - The Hartford Mutual Funds, Inc., et al.;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... the Act to invest in certain financial instruments. Applicants: The Hartford Mutual Funds, Inc., The... (iv) is also eligible to invest in securities (as defined in section 2(a)(36) of the Act) in reliance on rule 12d1-2 under the Act (each a ``Fund of Funds''), to also invest, to the extent...

  10. Mutual information area laws for thermal free fermions

    NASA Astrophysics Data System (ADS)

    Bernigau, H.; Kastoryano, M. J.; Eisert, J.

    2015-02-01

    We provide a rigorous and asymptotically exact expression of the mutual information of translationally invariant free fermionic lattice systems in a Gibbs state. In order to arrive at this result, we introduce a novel framework for computing determinants of Töplitz operators with smooth symbols, and for treating Töplitz matrices with system size dependent entries. The asymptotically exact mutual information for a partition of the 1D lattice satisfies an area law, with a prefactor which we compute explicitly. As examples, we discuss the fermionic XX model in one dimension and free fermionic models on the torus in higher dimensions in detail. Special emphasis is put on the discussion of the temperature dependence of the mutual information, scaling like the logarithm of the inverse temperature, hence confirming an expression suggested by conformal field theory. We also comment on the applicability of the formalism to treat open systems driven by quantum noise. In the appendix, we derive useful bounds to the mutual information in terms of purities. Finally, we provide a detailed error analysis for finite system sizes. This analysis is valuable in its own right for the abstract theory of Töplitz determinants.

  11. Development of Mutual Responsiveness Between Parents and Their Young Children

    ERIC Educational Resources Information Center

    Kochanska, Grazyna; Aksan, Nazan

    2004-01-01

    This comprehensive study of mutual responsiveness examined 102 mothers and 102 fathers interacting with their children at 7 and 15 months. Responsiveness was studied from developmental and individual differences perspectives, and assessed using macroscopic ratings and microscopic event coding. The latter captured parents' reactions to children's…

  12. Language Experience Shapes the Development of the Mutual Exclusivity Bias

    ERIC Educational Resources Information Center

    Houston-Price, Carmel; Caloghiris, Zoe; Raviglione, Eleonora

    2010-01-01

    Halberda (2003) demonstrated that 17-month-old infants, but not 14- or 16-month-olds, use a strategy known as mutual exclusivity (ME) to identify the meanings of new words. When 17-month-olds were presented with a novel word in an intermodal preferential looking task, they preferentially fixated a novel object over an object for which they already…

  13. Evolutionary dynamics of fluctuating populations with strong mutualism

    NASA Astrophysics Data System (ADS)

    Chotibut, Thiparat; Nelson, David

    2013-03-01

    Evolutionary game theory with finite interacting populations is receiving increased attention, including subtle phenomena associated with number fluctuations, i.e., ``genetic drift.'' Models of cooperation and competition often utilize a simplified Moran model, with a strictly fixed total population size. We explore a more general evolutionary model with independent fluctuations in the numbers of two distinct species, in a regime characterized by ``strong mutualism.'' The model has two absorbing states, each corresponding to fixation of one of the two species, and allows exploration of the interplay between growth, competition, and mutualism. When mutualism is favored, number fluctuations eventually drive the system away from a stable fixed point, characterized by cooperation, to one of the absorbing states. Well-mixed populations will thus be taken over by a single species in a finite time, despite the bias towards cooperation. We calculate both the fixation probability and the mean fixation time as a function of the initial conditions and carrying capacities in the strong mutualism regime, using the method of matched asymptotic expansions. Our results are compared to computer simulations.

  14. Using Mutual Information for Adaptive Item Comparison and Student Assessment

    ERIC Educational Resources Information Center

    Liu, Chao-Lin

    2005-01-01

    The author analyzes properties of mutual information between dichotomous concepts and test items. The properties generalize some common intuitions about item comparison, and provide principled foundations for designing item-selection heuristics for student assessment in computer-assisted educational systems. The proposed item-selection strategies…

  15. International Mutual Recognition: Progress and Prospects. Working Paper.

    ERIC Educational Resources Information Center

    Hager, Paul

    Increasing the mobility of service providers, including professionals, via mutual recognition (of regulatory systems) agreements (MRAs) has become a significant issue worldwide. Despite increasing interest in MRAs, it may be argued that MRAs are but one of a larger range of major developments that have fueled current interest in occupational…

  16. Fourth-order mutual coherence function in oceanic turbulence.

    PubMed

    Baykal, Yahya

    2016-04-10

    We have recently expressed the structure constant of atmospheric turbulence in terms of the oceanic turbulence parameters, which are the ratio of temperature to salinity contributions to the refractive index spectrum, rate of dissipation of kinetic energy per unit mass of fluid, rate of dissipation of the mean-squared temperature, wavelength, Kolmogorov microscale, and link length. In this paper, utilizing this recently found structure constant and the fourth-order mutual coherence function of atmospheric turbulence, we present the fourth-order mutual coherence function to be used in oceanic turbulence evaluations. Thus, the found fourth-order mutual coherence function of oceanic turbulence is evaluated for the special case of a point source located at the transmitter origin and at a single receiver point. The variations of this special case of the fourth-order mutual coherence function of oceanic turbulence against the changes in the ratio of temperature to salinity contributions to the refractive index spectrum, the rate of dissipation of kinetic energy per unit mass of fluid, the rate of dissipation of the mean-squared temperature, the wavelength, and the Kolmogorov microscale at various link lengths are presented. PMID:27139862

  17. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... capital requirements under part 167 of this chapter if a Federal savings association or 12 CFR part 390... a Federal savings association or 12 CFR part 390, subpart Z if a state savings association; And... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Mutual capital certificates. 163.74 Section...

  18. Functional analysis of mutual behavior in laboratory rats (Rattus norvegicus)

    PubMed Central

    Tan, Lavinia; Hackenberg, Timothy D.

    2015-01-01

    Three pairs of rats were trained to synchronize their lever pressing according to a mutual reinforcement contingency, in which alternating lever presses that fell within a 500-ms window were reinforced with food. In Experiment 1, rats worked in adjacent chambers separated by a transparent barrier, and the effects of the mutual reinforcement contingency were compared to those under yoked-control conditions that provided the same rate of food reinforcement but without the temporal coordination response requirement. In Experiment 2, coordinated behavior was compared with and without a barrier, and across different barrier types: transparent, opaque, wire mesh. In Experiment 3, the effects of social familiarity were assessed by switching partners, enabling a comparison of coordinated behavior with familiar and unfamiliar partners. The overall pattern of results shows that the coordinated behavior of two rats was (a) maintained by mutual reinforcement contingencies, (b) unrelated to the type or presence of a barrier separating the rats, and (c) sufficiently flexible to adjust to the presence and behavior of an unfamiliar partner. Taken as a whole, the study illustrates a promising approach to conceptualizing and analyzing behavioral mechanisms of mutual behavior, an important component of an integrated study of social behavior. PMID:26479279

  19. 12 CFR 544.5 - Federal mutual savings association bylaws.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... by the association. (3) Corporate governance procedures. A Federal mutual association may elect to follow the corporate governance procedures of the laws of the state where the main office of the... corporate governance procedures, and shall file a copy of such bylaws, which are effective upon...

  20. Functional analysis of mutual behavior in laboratory rats (Rattus norvegicus).

    PubMed

    Tan, Lavinia; Hackenberg, Timothy D

    2016-02-01

    Three pairs of rats were trained to synchronize their lever pressing according to a mutual reinforcement contingency, in which alternating lever presses that fell within a 500-ms window were reinforced with food. In Experiment 1, rats worked in adjacent chambers separated by a transparent barrier, and the effects of the mutual reinforcement contingency were compared with those under yoked-control conditions that provided the same rate of food reinforcement but without the temporal coordination response requirement. In Experiment 2, coordinated behavior was compared with and without a barrier, and across different barrier types: transparent, opaque, wire mesh. In Experiment 3, the effects of social familiarity were assessed by switching partners, enabling a comparison of coordinated behavior with familiar and unfamiliar partners. The overall pattern of results shows that the coordinated behavior of 2 rats was (a) maintained by mutual reinforcement contingencies, (b) unrelated to the type or presence of a barrier separating the rats, and (c) sufficiently flexible to adjust to the presence and behavior of an unfamiliar partner. Taken as a whole, the study illustrates a promising approach to conceptualizing and analyzing behavioral mechanisms of mutual behavior, an important component of an integrated study of social behavior. PMID:26479279