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Sample records for mutually unbiased bases

  1. 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.

  2. Mutually unbiased bases and generalized Bell states

    SciTech Connect

    Klimov, Andrei B.; Sych, Denis; Sanchez-Soto, Luis L.; Leuchs, Gerd

    2009-05-15

    We employ a straightforward relation between mutually unbiased and Bell bases to extend the latter in terms of a direct construction for the former. We analyze in detail the properties of these generalized Bell states, showing that they constitute an appropriate tool for testing entanglement in bipartite multiqudit systems.

  3. 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.

  4. 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.

  5. Improving Quantum State Estimation with Mutually Unbiased Bases

    NASA Astrophysics Data System (ADS)

    Adamson, R. B. A.; Steinberg, A. M.

    2010-07-01

    When used in quantum state estimation, projections onto mutually unbiased bases have the ability to maximize information extraction per measurement and to minimize redundancy. We present the first experimental demonstration of quantum state tomography of two-qubit polarization states to take advantage of mutually unbiased bases. We demonstrate improved state estimation as compared to standard measurement strategies and discuss how this can be understood from the structure of the measurements we use. We experimentally compared our method to the standard state estimation method for three different states and observe that the infidelity was up to 1.84±0.06 times lower by using our technique than it was by using standard state estimation methods.

  6. Mutually unbiased bases and Hadamard matrices of order six

    NASA Astrophysics Data System (ADS)

    Bengtsson, Ingemar; Bruzda, Wojciech; Ericsson, A.˚Sa; Larsson, Jan-A.˚Ke; Tadej, Wojciech; Życzkowski, Karol

    2007-05-01

    We report on a search for mutually unbiased bases (MUBs) in six dimensions. We find only triplets of MUBs, and thus do not come close to the theoretical upper bound 7. However, we point out that the natural habitat for sets of MUBs is the set of all complex Hadamard matrices of the given order, and we introduce a natural notion of distance between bases in Hilbert space. This allows us to draw a detailed map of where in the landscape the MUB triplets are situated. We use available tools, such as the theory of the discrete Fourier transform, to organize our results. Finally, we present some evidence for the conjecture that there exists a four dimensional family of complex Hadamard matrices of order 6. If this conjecture is true the landscape in which one may search for MUBs is much larger than previously thought.

  7. 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

  8. Mutually Unbiased Maximally Entangled Bases for the Bipartite System Cd⊗ C^{dk}

    NASA Astrophysics Data System (ADS)

    Nan, Hua; Tao, Yuan-Hong; Wang, Tian-Jiao; Zhang, Jun

    2016-10-01

    The construction of maximally entangled bases for the bipartite system Cd⊗ Cd is discussed firstly, and some mutually unbiased bases with maximally entangled bases are given, where 2≤ d≤5. Moreover, we study a systematic way of constructing mutually unbiased maximally entangled bases for the bipartite system Cd⊗ C^{dk}.

  9. 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.

  10. Entropic uncertainty relations and locking: Tight bounds for mutually unbiased bases

    SciTech Connect

    Ballester, Manuel A.; Wehner, Stephanie

    2007-02-15

    We prove tight entropic uncertainty relations for a large number of mutually unbiased measurements. In particular, we show that a bound derived from the result by Maassen and Uffink [Phys. Rev. Lett. 60, 1103 (1988)] for two such measurements can in fact be tight for up to {radical}(d) measurements in mutually unbiased bases. We then show that using more mutually unbiased bases does not always lead to a better locking effect. We prove that the optimal bound for the accessible information using up to {radical}(d) specific mutually unbiased bases is log d/2, which is the same as can be achieved by using only two bases. Our result indicates that merely using mutually unbiased bases is not sufficient to achieve a strong locking effect and we need to look for additional properties.

  11. 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.

  12. 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

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

    PubMed

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

    2013-09-25

    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.

  14. Two Types of Maximally Entangled Bases and Their Mutually Unbiased Property in Cd⊗ C^{d^' }}

    NASA Astrophysics Data System (ADS)

    Luo, Laizhen; Li, Xiaoyu; Tao, Yuanhong

    2016-08-01

    We first construct a new maximally entangled basis in bipartite systems Cd ⊗ C^{kd} (kin Z+) which is diffrent from the one in Tao et al. (Quantum Inf. Process. 14, 2291 (2015)), then we generalize such maximally entangled basis into arbitrary bipartite systems Cd ⊗ C^{d^' }}. We also study the mutual unbiased property of the two types of maximally entangled bases in bipartite systems Cd ⊗ C^{kd}. In particular, explicit examples in C2 ⊗ C4, C2 ⊗ C8 and C3 ⊗ C3 are presented.

  15. 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.

  16. 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.

  17. Information-disturbance theorem for mutually unbiased observables

    SciTech Connect

    Miyadera, Takayuki; Imai, Hideki

    2006-04-15

    We derive a version of information-disturbance theorems for mutually unbiased observables. We show that the information gain by Eve inevitably makes the outcomes by Bob in the conjugate basis not only erroneous but random.

  18. 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.

  19. Maximum unbiased validation (MUV) data sets for virtual screening based on PubChem bioactivity data.

    PubMed

    Rohrer, Sebastian G; Baumann, Knut

    2009-02-01

    Refined nearest neighbor analysis was recently introduced for the analysis of virtual screening benchmark data sets. It constitutes a technique from the field of spatial statistics and provides a mathematical framework for the nonparametric analysis of mapped point patterns. Here, refined nearest neighbor analysis is used to design benchmark data sets for virtual screening based on PubChem bioactivity data. A workflow is devised that purges data sets of compounds active against pharmaceutically relevant targets from unselective hits. Topological optimization using experimental design strategies monitored by refined nearest neighbor analysis functions is applied to generate corresponding data sets of actives and decoys that are unbiased with regard to analogue bias and artificial enrichment. These data sets provide a tool for Maximum Unbiased Validation (MUV) of virtual screening methods. The data sets and a software package implementing the MUV design workflow are freely available at http://www.pharmchem.tu-bs.de/lehre/baumann/MUV.html.

  20. 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.

  1. Multimodal Data Fusion Based on Mutual Information.

    PubMed

    Bramon, Roger; Boada, Imma; Bardera, Anton; Rodríguez, Joaquim; Feixas, Miquel; Puig, Josep; Sbert, Mateu

    2012-09-01

    Multimodal visualization aims at fusing different data sets so that the resulting combination provides more information and understanding to the user. To achieve this aim, we propose a new information-theoretic approach that automatically selects the most informative voxels from two volume data sets. Our fusion criteria are based on the information channel created between the two input data sets that permit us to quantify the information associated with each intensity value. This specific information is obtained from three different ways of decomposing the mutual information of the channel. In addition, an assessment criterion based on the information content of the fused data set can be used to analyze and modify the initial selection of the voxels by weighting the contribution of each data set to the final result. The proposed approach has been integrated in a general framework that allows for the exploration of volumetric data models and the interactive change of some parameters of the fused data set. The proposed approach has been evaluated on different medical data sets with very promising results.

  2. 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

  3. An unbiased FIR filter for TIE model of a local clock in applications to GPS-based timekeeping.

    PubMed

    Shmaliy, Yuriy S

    2006-05-01

    An unbiased finite impulse response (FIR) filter is proposed to estimate the time-interval error (TIE) K-degree polynomial model of a local clock in global positioning system (GPS)-based timekeeping in the presence of noise that is not obligatory Gaussian. Generic coefficients for the unbiased FIRs are derived. The low-degree FIRs and noise power gains are given. An estimation algorithm is proposed and examined for the TIE measurements of a crystal clock in the presence of the uniformly distributed sawtooth noise induced by the multichannel GPS timing receiver. Based upon this algorithm, we show that the unbiased FIR estimates are consistent with the reference (rubidium) measurements and fit them better than the standard Kalman filter.

  4. An Unbiased Method To Build Benchmarking Sets for Ligand-Based Virtual Screening and its Application To GPCRs

    PubMed Central

    2015-01-01

    Benchmarking data sets have become common in recent years for the purpose of virtual screening, though the main focus had been placed on the structure-based virtual screening (SBVS) approaches. Due to the lack of crystal structures, there is great need for unbiased benchmarking sets to evaluate various ligand-based virtual screening (LBVS) methods for important drug targets such as G protein-coupled receptors (GPCRs). To date these ready-to-apply data sets for LBVS are fairly limited, and the direct usage of benchmarking sets designed for SBVS could bring the biases to the evaluation of LBVS. Herein, we propose an unbiased method to build benchmarking sets for LBVS and validate it on a multitude of GPCRs targets. To be more specific, our methods can (1) ensure chemical diversity of ligands, (2) maintain the physicochemical similarity between ligands and decoys, (3) make the decoys dissimilar in chemical topology to all ligands to avoid false negatives, and (4) maximize spatial random distribution of ligands and decoys. We evaluated the quality of our Unbiased Ligand Set (ULS) and Unbiased Decoy Set (UDS) using three common LBVS approaches, with Leave-One-Out (LOO) Cross-Validation (CV) and a metric of average AUC of the ROC curves. Our method has greatly reduced the “artificial enrichment” and “analogue bias” of a published GPCRs benchmarking set, i.e., GPCR Ligand Library (GLL)/GPCR Decoy Database (GDD). In addition, we addressed an important issue about the ratio of decoys per ligand and found that for a range of 30 to 100 it does not affect the quality of the benchmarking set, so we kept the original ratio of 39 from the GLL/GDD. PMID:24749745

  5. An unbiased method to build benchmarking sets for ligand-based virtual screening and its application to GPCRs.

    PubMed

    Xia, Jie; Jin, Hongwei; Liu, Zhenming; Zhang, Liangren; Wang, Xiang Simon

    2014-05-27

    Benchmarking data sets have become common in recent years for the purpose of virtual screening, though the main focus had been placed on the structure-based virtual screening (SBVS) approaches. Due to the lack of crystal structures, there is great need for unbiased benchmarking sets to evaluate various ligand-based virtual screening (LBVS) methods for important drug targets such as G protein-coupled receptors (GPCRs). To date these ready-to-apply data sets for LBVS are fairly limited, and the direct usage of benchmarking sets designed for SBVS could bring the biases to the evaluation of LBVS. Herein, we propose an unbiased method to build benchmarking sets for LBVS and validate it on a multitude of GPCRs targets. To be more specific, our methods can (1) ensure chemical diversity of ligands, (2) maintain the physicochemical similarity between ligands and decoys, (3) make the decoys dissimilar in chemical topology to all ligands to avoid false negatives, and (4) maximize spatial random distribution of ligands and decoys. We evaluated the quality of our Unbiased Ligand Set (ULS) and Unbiased Decoy Set (UDS) using three common LBVS approaches, with Leave-One-Out (LOO) Cross-Validation (CV) and a metric of average AUC of the ROC curves. Our method has greatly reduced the "artificial enrichment" and "analogue bias" of a published GPCRs benchmarking set, i.e., GPCR Ligand Library (GLL)/GPCR Decoy Database (GDD). In addition, we addressed an important issue about the ratio of decoys per ligand and found that for a range of 30 to 100 it does not affect the quality of the benchmarking set, so we kept the original ratio of 39 from the GLL/GDD.

  6. 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

  7. 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.

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

    PubMed

    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.

  9. 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.

  10. 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.

  11. 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.

  12. [Mutual information-based correlation analysis of herbs against insomnia].

    PubMed

    Tian, Jin; Liu, Ren-quan

    2015-10-01

    This paper aims to analyze Professor Guo Rongjuan's medication experience on insomnia therapy based on the Traditional Chinese Medicine (TCM) Inheritance Support Plat. First, TCM formulae prescribed by Professor Guo for insomnia therapy were collected from the TCM Inheritance Support Plat. Next, unsupervised data mining algorithms, including apriori, modified mutual-information, and entropy clustering of complex system were applied to obtain the frequencies for different herbs and identify the association rules among the herbs. Accordingly, we can gain new insights into Professor Guo's medication experience on insomnia therapy. Based on analysis of 3 084 formulae, we determined the frequencies for herbs in the formulae and identified the association rules among these herbs. At last, 41 core combinations and 7 new formulae were obtained. The identified medication experience conform with Professor Guo's views on the etiology and pathogenesis of insomnia: "pathogenic fire derived from stagnation of liver-QI (Gan Yu Hua Huo)" is the core pathogenesis of insomnia; "liver stagnation and spleen deficiency" and "chronic illness transferred to kidney" are the main features for insomnia. The TCM Inheritance Support Plat is of great practical value for mining clinical experience of famous TCM doctors.

  13. Mutual-information-based registration for ultrasound and CT datasets

    NASA Astrophysics Data System (ADS)

    Firle, Evelyn A.; Wesarg, Stefan; Dold, Christian

    2004-05-01

    In many applications for minimal invasive surgery the acquisition of intra-operative medical images is helpful if not absolutely necessary. Especially for Brachytherapy imaging is critically important to the safe delivery of the therapy. Modern computed tomography (CT) and magnetic resonance (MR) scanners allow minimal invasive procedures to be performed under direct imaging guidance. However, conventional scanners do not have real-time imaging capability and are expensive technologies requiring a special facility. Ultrasound (U/S) is a much cheaper and one of the most flexible imaging modalities. It can be moved to the application room as required and the physician sees what is happening as it occurs. Nevertheless it may be easier to interpret these 3D intra-operative U/S images if they are used in combination with less noisier preoperative data such as CT. The purpose of our current investigation is to develop a registration tool for automatically combining pre-operative CT volumes with intra-operatively acquired 3D U/S datasets. The applied alignment procedure is based on the information theoretic approach of maximizing the mutual information of two arbitrary datasets from different modalities. Since the CT datasets include a much bigger field of view we introduced a bounding box to narrow down the region of interest within the CT dataset. We conducted a phantom experiment using a CIRS Model 53 U/S Prostate Training Phantom to evaluate the feasibility and accuracy of the proposed method.

  14. 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.

  15. Designing redox potential-controlled protein switches based on mutually exclusive proteins.

    PubMed

    Peng, Qing; Kong, Na; Wang, Hui-Chuan Eileen; Li, Hongbin

    2012-08-01

    Synthetic/artificial protein switches provide an efficient means of controlling protein functions using chemical signals and stimuli. Mutually exclusive proteins, in which only the host or guest domain can remain folded at a given time owing to conformational strain, have been used to engineer novel protein switches that can switch enzymatic functions on and off in response to ligand binding. To further explore the potential of mutually exclusive proteins as protein switches and sensors, we report here a new redox-based approach to engineer a mutually exclusive folding-based protein switch. By introducing a disulfide bond into the host domain of a mutually exclusive protein, we demonstrate that it is feasible to use redox potential to switch the host domain between its folded and unfolded conformations via the mutually exclusive folding mechanism, and thus switching the functionality of the host domain on and off. Our study opens a new and potentially general avenue that uses mutually exclusive proteins to design novel switches able to control the function of a variety of proteins.

  16. 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…

  17. Groups in Latin America: Comunidades Eclesial de Base as Mutual Support Groups.

    ERIC Educational Resources Information Center

    McWhirter, Benedict T.; And Others

    1988-01-01

    Describes Comunidades Eclesial de Base (CEBs) or base communities which are self-help and mutual aid groups that assist in alleviating the effects of poverty and powerlessness in Latin America. Discusses two potential problems of CEBs - that they may encourage either passivity or increased violence. (Author/NB)

  18. Chaos synchronization and communication of mutual coupling laser ring based on incoherent injection

    NASA Astrophysics Data System (ADS)

    Hu, Juju; Ma, Junshan; Lin, Jinzhong

    2009-11-01

    A chaos secure communication system of mutual coupling lasers ring based on incoherent optical injection is proposed, in which fine tuning of optical frequency is not required compared with other schemes based on coherent optical injection. Therefore the secure communication scheme is attractive for experimental investigation. The dynamics of semiconductor lasers in the coupling ring are examined. Numerical investigations indicate that zero lag synchronization can be achieved under equal coupling time and strength of mutual coupling. Furthermore, by chaos shift keying (CSK), secure communication is simulated with a random bit stream of 1.0Gbit/s. The results confirm the possibility of applying incoherent schemes of mutual coupling lasers ring to realize chaotic secure communication.

  19. Model-based image processing using snakes and mutual information

    NASA Astrophysics Data System (ADS)

    von Klinski, Sebastian; Derz, Claus; Weese, David; Tolxdorff, Thomas

    2000-06-01

    Any segmentation approach assumes certain knowledge concerning data modalities, relevant organs and their imaging characteristics. These assumptions are necessary for developing criteria by which to separate the organ in question from the surrounding tissue. Typical assumptions are that the organs have homogeneous gray-value characteristics (region growing, region merging, etc.), specific gray-value patterns (classification methods), continuous edges (edge-based approaches), smooth and strong edges (snake approaches), or any combination of these. In most cases, such assumptions are invalid, at least locally. Consequently, these approaches prove to be time consuming either in their parameterization or execution. Further, the low result quality makes post- processing necessary. Our aim was to develop a segmentation approach for large 3D data sets (e.g., CT and MRI) that requires a short interaction time and that can easily be adapted to different organs and data materials. This has been achieved by exploiting available knowledge about data material and organ topology using anatomical models that have been constructed from previously segmented data sets. In the first step, the user manually specifies the general context of the data material and specifies anatomical landmarks. Then this information is used to automatically select a corresponding reference model, which is geometrically adjusted to the current data set. In the third step, a model-based snake approach is applied to determine the correct segmentation of the organ in question. Analogously, this approach can be used for model-based interpolation and registration.

  20. The evolution of mutualism.

    PubMed

    Leigh, E G

    2010-12-01

    Like altruism, mutualism, cooperation between species, evolves only by enhancing all participants' inclusive fitness. Mutualism evolves most readily between members of different kingdoms, which pool complementary abilities for mutual benefit: some of these mutualisms represent major evolutionary innovations. Mutualism cannot persist if cheating annihilates its benefits. In long-term mutualisms, symbioses, at least one party associates with the other nearly all its life. Usually, a larger host harbours smaller symbionts. Cheating is restrained by vertical transmission, as in Buchnera; partner fidelity, as among bull-thorn acacias and protective ants; test-based choice of symbionts, as bobtail squid choose bioluminescent bacteria; or sanctioning nonperforming symbionts, as legumes punish nonperforming nitrogen-fixing bacteria. Mutualisms involving brief exchanges, as among plants and seed-dispersers, however, persist despite abundant cheating. Both symbioses and brief-exchange mutualisms have transformed whole ecosystems. These mutualisms may be steps towards ecosystems which, like Adam Smith's ideal economy, serve their members' common good.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. Feature selection using mutual information based uncertainty measures for tumor classification.

    PubMed

    Sun, Lin; Xu, Jiucheng

    2014-01-01

    Feature selection is a key problem in tumor classification and related tasks. This paper presents a tumor classification approach with neighborhood rough set-based feature selection. First, some uncertainty measures such as neighborhood entropy, conditional neighborhood entropy, neighborhood mutual information and neighborhood conditional mutual information, are introduced to evaluate the relevance between genes and related decision in neighborhood rough set. Then some important properties and propositions of these measures are investigated, and the relationships among these measures are established as well. By using improved minimal-Redundancy-Maximal-Relevancy, combined with sequential forward greedy search strategy, a novel feature selection algorithm with low time complexity is proposed. Finally, several cancer classification tasks are demonstrated using the proposed approach. Experimental results show that the proposed algorithm is efficient and effective.

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

    PubMed

    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

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

    PubMed

    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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. A stable, unbiased, long-term satellite based data record of sea surface temperature from ESA's Climate Change Initiative

    NASA Astrophysics Data System (ADS)

    Rayner, Nick; Good, Simon; Merchant, Chris

    2013-04-01

    The study of climate change demands long-term, stable observational records of climate variables such as sea surface temperature (SST). ESA's Climate Change Initiative was set up to unlock the potential of satellite data records for this purpose. As part of this initiative, 13 projects were established to develop the data records for different essential climate variables - aerosol, cloud, fire, greenhouse gases, glaciers, ice sheets, land cover, ocean colour, ozone, sea ice, sea level, soil moisture and SST. In this presentation we describe the development work that has taken place in the SST project and present new prototype data products that are available now for users to trial. The SST project began in 2010 and has now produced two prototype products. The first is a long-term product (covering mid-1991 - 2010 currently, but with a view to update this in the future), which prioritises length of data record and stability over other considerations. It is based on data from the Along-Track Scanning Radiometer (ATSR) and Advanced Very-High Resolution Radiometer (AVHRR) series of satellite instruments. The product aims to combine the favourable stability and bias characteristics of ATSR data with the geographical coverage achieved with the AVHRR series. Following an algorithm selection process, an optimal estimation approach to retrieving SST from the satellite measurements from both sensors was adopted. The retrievals do not depend on in situ data and so this data record represents an independent assessment of SST change. In situ data are, however, being used to validate the resulting data. The second data product demonstrates the coverage that can be achieved using the modern satellite observing system including, for example, geostationary satellite data. Six months worth of data have been processed for this demonstration product. The prototype SST products will be released in April to users to trial in their work. The long term product will be available as

  14. 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.

  15. 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.

  16. 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.

  17. Spacer/Linker Based Synthesis and Biological Evaluation of Mutual Prodrugs as Antiinflammatory Agents

    PubMed Central

    Velingkar, V. S.; Jain, D. R.; Ahire, D. C.

    2010-01-01

    Mutual prodrugs of some antiinflammatory agents were synthesized with the aim of improving the therapeutic index through prevention of gastrointestinal complications and to check the efficiency of release of the parent drug in presence of spacer. These mutual prodrugs were synthesized by direct condensation method using dicyclohexyl carbodiimide as a coupling agent and glycine as a spacer. The title compounds were characterized by spectral techniques and the release of the parent drug from mutual prodrug was studied in two different non-enzymatic buffer solutions at pH 1.2, pH 7.4 and in 80% human plasma. All mutual prodrugs exhibited encouraging hydrolysis profile in 80% human plasma. Biological activity of title compounds was studied by carrageenan-induced paw edema method. From the results obtained, it was concluded that these compounds retain the antiinflammatory action. PMID:21694998

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

    PubMed

    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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Linear unbiased prediction of clock errors.

    PubMed

    Shmaliy, Yuriy S

    2009-09-01

    In this paper, we propose a new formula for linear unbiased prediction of the local clock timescales. To predict future errors over all the measurement data, a new gain is derived for the p-step ramp unbiased finite impulse response (FIR) predictor. We then show that this gain gives the best linear unbiased fit suitable for forming the prediction vector. The predictor proposed is consistent with linear regression and best linear unbiased estimator. Applications are given for a crystal clock and the USNO Master Clock.

  4. 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.

  5. 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…

  6. 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

  7. Multifunction extension of simplex optimization method for mutual information-based registration of ultrasound volumes

    NASA Astrophysics Data System (ADS)

    Zagrodsky, Vladimir; Shekhar, Raj; Cornhill, J. Fredrick

    2001-07-01

    Mutual information has been demonstrated to be an accurate and reliable criterion function to perform registration of medical data. Due to speckle noise, ultrasound volumes do not provide a smooth mutual information function. Consequently the optimization technique used must be robust enough to avoid local maxima and converge on the desired global maximum eventually. While the well-known downhill simplex optimization uses a single criterion function, our extension to multi-function optimization uses three criterion functions, namely mutual information computed at three levels of intensity quantization and hence three degrees of noise suppression. Registration was performed with rigid as well as simple non-rigid transformation modes for real-time 3D ultrasound datasets of the left ventricle. Pairs of frames corresponding to the most stationary end- diastolic cardiac phase were chosen, and an initial misalignment was artificially introduced between them. The multi-function simplex optimization reduced the failure rate by a factor of two in comparison to the standard simplex optimization, while the average accuracy for the successful cases was unchanged. A more robust registration resulted form the parallel use of criterion functions. The additional computational cost was negligible, as each of the three implementations of the mutual information used the same joint histogram and required no extra spatial transformation.

  8. 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.

  9. 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

  10. 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.

  11. A new EEG synchronization strength analysis method: S-estimator based normalized weighted-permutation mutual information.

    PubMed

    Cui, Dong; Pu, Weiting; Liu, Jing; Bian, Zhijie; Li, Qiuli; Wang, Lei; Gu, Guanghua

    2016-10-01

    Synchronization is an important mechanism for understanding information processing in normal or abnormal brains. In this paper, we propose a new method called normalized weighted-permutation mutual information (NWPMI) for double variable signal synchronization analysis and combine NWPMI with S-estimator measure to generate a new method named S-estimator based normalized weighted-permutation mutual information (SNWPMI) for analyzing multi-channel electroencephalographic (EEG) synchronization strength. The performances including the effects of time delay, embedding dimension, coupling coefficients, signal to noise ratios (SNRs) and data length of the NWPMI are evaluated by using Coupled Henon mapping model. The results show that the NWPMI is superior in describing the synchronization compared with the normalized permutation mutual information (NPMI). Furthermore, the proposed SNWPMI method is applied to analyze scalp EEG data from 26 amnestic mild cognitive impairment (aMCI) subjects and 20 age-matched controls with normal cognitive function, who both suffer from type 2 diabetes mellitus (T2DM). The proposed methods NWPMI and SNWPMI are suggested to be an effective index to estimate the synchronization strength.

  12. A new EEG synchronization strength analysis method: S-estimator based normalized weighted-permutation mutual information.

    PubMed

    Cui, Dong; Pu, Weiting; Liu, Jing; Bian, Zhijie; Li, Qiuli; Wang, Lei; Gu, Guanghua

    2016-10-01

    Synchronization is an important mechanism for understanding information processing in normal or abnormal brains. In this paper, we propose a new method called normalized weighted-permutation mutual information (NWPMI) for double variable signal synchronization analysis and combine NWPMI with S-estimator measure to generate a new method named S-estimator based normalized weighted-permutation mutual information (SNWPMI) for analyzing multi-channel electroencephalographic (EEG) synchronization strength. The performances including the effects of time delay, embedding dimension, coupling coefficients, signal to noise ratios (SNRs) and data length of the NWPMI are evaluated by using Coupled Henon mapping model. The results show that the NWPMI is superior in describing the synchronization compared with the normalized permutation mutual information (NPMI). Furthermore, the proposed SNWPMI method is applied to analyze scalp EEG data from 26 amnestic mild cognitive impairment (aMCI) subjects and 20 age-matched controls with normal cognitive function, who both suffer from type 2 diabetes mellitus (T2DM). The proposed methods NWPMI and SNWPMI are suggested to be an effective index to estimate the synchronization strength. PMID:27451314

  13. Unbiased Black-Box Complexities of Jump Functions.

    PubMed

    Doerr, Benjamin; Doerr, Carola; Kötzing, Timo

    2015-01-01

    We analyze the unbiased black-box complexities of jump functions with small, medium, and large sizes of the fitness plateau surrounding the optimal solution. Among other results, we show that when the jump size is (1/2 - ε), that is, when only a small constant fraction of the fitness values is visible, then the unbiased black-box complexities for arities 3 and higher are of the same order as those for the simple OneMax function. Even for the extreme jump function, in which all but the two fitness values n/2 and n are blanked out, polynomial time mutation-based (i.e., unary unbiased) black-box optimization algorithms exist. This is quite surprising given that for the extreme jump function almost the whole search space (all but a Θ(n(-1/2)) fraction) is a plateau of constant fitness. To prove these results, we introduce new tools for the analysis of unbiased black-box complexities, for example, selecting the new parent individual not only by comparing the fitnesses of the competing search points but also by taking into account the (empirical) expected fitnesses of their offspring.

  14. 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…

  15. Equilibrium population dynamics when mating is by mutual choice based on age.

    PubMed

    Alpern, Steve; Katrantzi, Ioanna; Ramsey, David

    2014-06-01

    We consider a steady state model of mutual mate choice in which an individual's mate preferences depend on his/her age, and the preferences are over the ages of prospective mates of the opposite sex. We present a discrete time (and age) model corresponding to successive mating seasons. Males are fertile for m periods (corresponding to 'age' i=1 to m) and females for n≤m periods (they have ages j=1 to n), which is all that distinguishes the sexes. Although we can deal with arbitrary preferences, we concentrate on a simple fertility model where the common utility to a male age i and female age j who mate is the number K=min(m-i+1,n-j+1) of future periods of joint fertility. The incoming sex ratio R of age 1 males to age 1 females is given exogenously. In each period individuals are randomly (non assortatively) matched and form a mated couple by mutual consent; otherwise they go into the next period unmated and older. We derive properties of equilibrium threshold acceptance strategies and establish the existence of time-invariant age distributions. Our methods determine the age distribution of couples at marriage (mating) and the population sex ratio (OSR) at equilibrium. Since this can be determined empirically in a population, our model can be used to rule out most systems of age preferences (those not consistent with the observed distribution). This extends earlier models of mutual choice with one dimensional types of Alpern and Reyniers [1999. Strategic mating with homotypic preferences. J. Theor. Biol. 198, 71-88; 2005. Strategic mating with common preferences. J. Theor. Biol. 237, 337-354] where individuals sought, respectively, individuals with similar or high types, but in those models an individual's type was fixed over time. Under the simple fertility model, at equilibrium the maximum age of an acceptable partner is increasing in the age of the searcher. Our results relate to discussions in the literature regarding optimal parental age differences, age

  16. Equilibrium population dynamics when mating is by mutual choice based on age.

    PubMed

    Alpern, Steve; Katrantzi, Ioanna; Ramsey, David

    2014-06-01

    We consider a steady state model of mutual mate choice in which an individual's mate preferences depend on his/her age, and the preferences are over the ages of prospective mates of the opposite sex. We present a discrete time (and age) model corresponding to successive mating seasons. Males are fertile for m periods (corresponding to 'age' i=1 to m) and females for n≤m periods (they have ages j=1 to n), which is all that distinguishes the sexes. Although we can deal with arbitrary preferences, we concentrate on a simple fertility model where the common utility to a male age i and female age j who mate is the number K=min(m-i+1,n-j+1) of future periods of joint fertility. The incoming sex ratio R of age 1 males to age 1 females is given exogenously. In each period individuals are randomly (non assortatively) matched and form a mated couple by mutual consent; otherwise they go into the next period unmated and older. We derive properties of equilibrium threshold acceptance strategies and establish the existence of time-invariant age distributions. Our methods determine the age distribution of couples at marriage (mating) and the population sex ratio (OSR) at equilibrium. Since this can be determined empirically in a population, our model can be used to rule out most systems of age preferences (those not consistent with the observed distribution). This extends earlier models of mutual choice with one dimensional types of Alpern and Reyniers [1999. Strategic mating with homotypic preferences. J. Theor. Biol. 198, 71-88; 2005. Strategic mating with common preferences. J. Theor. Biol. 237, 337-354] where individuals sought, respectively, individuals with similar or high types, but in those models an individual's type was fixed over time. Under the simple fertility model, at equilibrium the maximum age of an acceptable partner is increasing in the age of the searcher. Our results relate to discussions in the literature regarding optimal parental age differences, age

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

    2013-07-24

    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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

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

    PubMed

    Jarosz, Daniel F; Brown, Jessica C S; Walker, Gordon A; Datta, Manoshi S; Ung, W Lloyd; Lancaster, Alex K; Rotem, Assaf; Chang, Amelia; Newby, Gregory A; Weitz, David A; Bisson, Linda F; Lindquist, Susan

    2014-08-28

    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.

  10. 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

  11. 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.

  12. Linear and nonlinear information flow based on time delayed mutual information method and its application to corticomuscular interaction

    PubMed Central

    Jin, Seung-Hyun; Lin, Peter; Hallett, Mark

    2010-01-01

    Objective To propose a model-free method to show linear and nonlinear information flow based on time delayed mutual information (TDMI) by employing uni- and bi-variate surrogate tests and to investigate whether there are contributions of the nonlinear information flow in corticomuscular (CM) interaction. Methods Using simulated data, we tested whether our method would successfully detect the direction of information flow and identify a relationship between two simulated time series. As an experimental data application, we applied this method to investigate CM interaction during a right wrist extension task. Results Results of simulation tests show that we can correctly detect the direction of information flow and the relationship between two time series without a prior knowledge of the dynamics of their generating systems. As experimental results, we found both linear and nonlinear information flow from contralateral sensorimotor cortex to muscle. Conclusions Our method is a viable model-free measure of temporally varying causal interactions that is capable of distinguishing linear and nonlinear information flow. With respect to experimental application, there are both linear and nonlinear information flows in CM interaction from contralateral sensorimotor cortex to muscle, which may reflect the motor command from brain to muscle. Significance This is the first study to show separate linear and nonlinear information flow in CM interaction. PMID:20044309

  13. [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

  14. [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.

  15. 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.

  16. 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)

  17. Decision rules for unbiased inventory estimates

    NASA Technical Reports Server (NTRS)

    Argentiero, P. D.; Koch, D.

    1979-01-01

    An efficient and accurate procedure for estimating inventories from remote sensing scenes is presented. In place of the conventional and expensive full dimensional Bayes decision rule, a one-dimensional feature extraction and classification technique was employed. It is shown that this efficient decision rule can be used to develop unbiased inventory estimates and that for large sample sizes typical of satellite derived remote sensing scenes, resulting accuracies are comparable or superior to more expensive alternative procedures. Mathematical details of the procedure are provided in the body of the report and in the appendix. Results of a numerical simulation of the technique using statistics obtained from an observed LANDSAT scene are included. The simulation demonstrates the effectiveness of the technique in computing accurate inventory estimates.

  18. Creating a TALE protein with unbiased 5'-T binding.

    PubMed

    Tsuji, Shogo; Futaki, Shiroh; Imanishi, Miki

    2013-11-01

    Transcription activator-like effectors (TALEs) are convenient tools for genome engineering at specific genomic sites. However, their use is constrained because most TALE binding sites are preceded by a highly conserved 5' terminal T nucleotide (5'-T). To remove the 5'-T constraint, we substituted tryptophan 232 in the repeat-1 loop region of the dHax3 N-terminal domain for other amino acids. Furthermore, we randomized four amino acid residues of the hairpin loop region of repeat-1. Although point mutation was insufficient to remove the 5'-T constraint, directed evolution from the randomized library yielded repeat-1 mutants with unbiased targeting sites for 5'-bases. Our result indicates that the repeat-1 loop region of dHax3 is important for 5'-base accommodation, and that molecular evolution of repeat-1 of TALEs is an efficient strategy to remove the 5'-T constraint and thus allow targeting of any DNA sequences.

  19. 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

  20. Unbiased Deep Sequencing of RNA Viruses from Clinical Samples

    PubMed Central

    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

  1. 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

  2. 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.

  3. 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)

  4. 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.

  5. 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

  6. Mutualisms and Population Regulation: Mechanism Matters

    PubMed Central

    Jha, Shalene; Allen, David; Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2012-01-01

    For both applied and theoretical ecological science, the mutualism between ants and their hemipteran partners is iconic. In this well-studied interaction, ants are assumed to provide hemipterans protection from natural enemies in exchange for nutritive honeydew. Despite decades of research and the potential importance in pest control, the precise mechanism producing this mutualism remains contested. By analyzing maximum likelihood parameter estimates of a hemipteran population model, we show that the mechanism of the mutualism is direct, via improved hemipteran growth rates, as opposed to the frequently assumed indirect mechanism, via harassment of the specialist parasites and predators of the hemipterans. Broadly, this study demonstrates that the management of mutualism-based ecosystem services requires a mechanistic understanding of mutualistic interactions. A consequence of this finding is the counter intuitive demonstration that preserving ant participation in the ant-hemipteran mutualism may be the best way of insuring pest control. PMID:22927978

  7. 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

  8. 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

  9. 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.

  10. 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

  11. TINKTEP: A fully self-consistent, mutually polarizable QM/MM approach based on the AMOEBA force field

    NASA Astrophysics Data System (ADS)

    Dziedzic, Jacek; Mao, Yuezhi; Shao, Yihan; Ponder, Jay; Head-Gordon, Teresa; Head-Gordon, Martin; Skylaris, Chris-Kriton

    2016-09-01

    We present a novel quantum mechanical/molecular mechanics (QM/MM) approach in which a quantum subsystem is coupled to a classical subsystem described by the AMOEBA polarizable force field. Our approach permits mutual polarization between the QM and MM subsystems, effected through multipolar electrostatics. Self-consistency is achieved for both the QM and MM subsystems through a total energy minimization scheme. We provide an expression for the Hamiltonian of the coupled QM/MM system, which we minimize using gradient methods. The QM subsystem is described by the onetep linear-scaling DFT approach, which makes use of strictly localized orbitals expressed in a set of periodic sinc basis functions equivalent to plane waves. The MM subsystem is described by the multipolar, polarizable force field AMOEBA, as implemented in tinker. Distributed multipole analysis is used to obtain, on the fly, a classical representation of the QM subsystem in terms of atom-centered multipoles. This auxiliary representation is used for all polarization interactions between QM and MM, allowing us to treat them on the same footing as in AMOEBA. We validate our method in tests of solute-solvent interaction energies, for neutral and charged molecules, demonstrating the simultaneous optimization of the quantum and classical degrees of freedom. Encouragingly, we find that the inclusion of explicit polarization in the MM part of QM/MM improves the agreement with fully QM calculations.

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

    PubMed

    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.

  13. 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

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

    DOE PAGES

    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

  15. 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.

  16. 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.…

  17. 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.

  18. 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

  19. 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

  20. An unbiased Hessian representation for Monte Carlo PDFs

    NASA Astrophysics Data System (ADS)

    Carrazza, Stefano; Forte, Stefano; Kassabov, Zahari; Latorre, José Ignacio; Rojo, Juan

    2015-08-01

    We develop a methodology for the construction of a Hessian representation of Monte Carlo sets of parton distributions, based on the use of a subset of the Monte Carlo PDF replicas as an unbiased linear basis, and of a genetic algorithm for the determination of the optimal basis. We validate the methodology by first showing that it faithfully reproduces a native Monte Carlo PDF set (NNPDF3.0), and then, that if applied to Hessian PDF set (MMHT14) which was transformed into a Monte Carlo set, it gives back the starting PDFs with minimal information loss. We then show that, when applied to a large Monte Carlo PDF set obtained as combination of several underlying sets, the methodology leads to a Hessian representation in terms of a rather smaller set of parameters (MC-H PDFs), thereby providing an alternative implementation of the recently suggested Meta-PDF idea and a Hessian version of the recently suggested PDF compression algorithm (CMC-PDFs). The mc2hessian conversion code is made publicly available together with (through LHAPDF6) a Hessian representations of the NNPDF3.0 set, and the MC-H PDF set.

  1. 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.

  2. 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.

  3. Identifying Homogeneous Subgroups in Neurological Disorders: Unbiased Recursive Partitioning in Cervical Complete Spinal Cord Injury.

    PubMed

    Tanadini, Lorenzo G; Steeves, John D; Hothorn, Torsten; Abel, Rainer; Maier, Doris; Schubert, Martin; Weidner, Norbert; Rupp, Rüdiger; Curt, Armin

    2014-07-01

    Background The reliable stratification of homogeneous subgroups and the prediction of future clinical outcomes within heterogeneous neurological disorders is a particularly challenging task. Nonetheless, it is essential for the implementation of targeted care and effective therapeutic interventions. Objective This study was designed to assess the value of a recently developed regression tool from the family of unbiased recursive partitioning methods in comparison to established statistical approaches (eg, linear and logistic regression) for predicting clinical endpoints and for prospective patients' stratification for clinical trials. Methods A retrospective, longitudinal analysis of prospectively collected neurological data from the European Multicenter study about Spinal Cord Injury (EMSCI) network was undertaken on C4-C6 cervical sensorimotor complete subjects. Predictors were based on a broad set of early (<2 weeks) clinical assessments. Endpoints were based on later clinical examinations of upper extremity motor scores and recovery of motor levels, at 6 and 12 months, respectively. Prediction accuracy for each statistical analysis was quantified by resampling techniques. Results For all settings, overlapping confidence intervals indicated similar prediction accuracy of unbiased recursive partitioning to established statistical approaches. In addition, unbiased recursive partitioning provided a direct way of identification of more homogeneous subgroups. The partitioning is carried out in a data-driven manner, independently from a priori decisions or predefined thresholds. Conclusion Unbiased recursive partitioning techniques may improve prediction of future clinical endpoints and the planning of future SCI clinical trials by providing easily implementable, data-driven rationales for early patient stratification based on simple decision rules and clinical read-outs.

  4. Antenna-coupled unbiased detectors for LW-IR regime

    NASA Astrophysics Data System (ADS)

    Tiwari, Badri Nath

    At room temperature (300K), the electromagnetic (EM) radiation emitted by humans and other living beings peaks mostly in the long-wavelength infrared (LW-IR) regime. And since the atmosphere shows relatively little absorption in this band, applications such as target detection, tracking, active homing, and navigation in autonomous vehicles extensively use the LW-IR frequency range. The present research work is focused on developing antenna-based, uncooled, and unbiased detectors for the LW-IR regime. In the first part of this research, antenna-coupled metal-oxide-metal diodes (ACMOMD) are investigated. In response to the EM radiation, high-frequency antenna currents are induced in the antenna. An asymmetric-barrier Al-Al2O3-Pt MOM diode rectifies the antenna currents. Two different types of fabrication processes have been developed for ACMOMDs namely one-step lithography and two-step lithography. The major drawbacks of MOM-based devices include hard-to-control fabrication processes, generally very high zero-biased resistances, and vulnerability to electrostatic discharges, leading to unstable electrical characteristics. The second part of this research focuses on the development of unbiased LW-IR sensors based on the Seebeck effect. If two different metals are joined together at one end and their other ends are open-circuited, and if a non-zero temperature difference exists between the joined end and the open ends, then a non-zero open-circuit voltage can be measured between the open ends of the wires. Based on this effect, we have developed antenna-coupled nano-thermocouples (ACNTs) in which radiation-induced antenna currents produce polarization-dependent heating of the joined end of the two metals whereas the open ends remain at substrate temperature. This polarization-dependent heating induces polarization-dependent temperature difference between the joined end and the open ends of the metals leading to a polarization-dependent open-circuit voltage between the

  5. 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.

  6. 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

  7. 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…

  8. Unbiased Average Age-Appropriate Atlases for Pediatric Studies

    PubMed Central

    Fonov, Vladimir; Evans, Alan C.; Botteron, Kelly; Almli, C. Robert; McKinstry, Robert C.; Collins, D. Louis

    2010-01-01

    Spatial normalization, registration, and segmentation techniques for Magnetic Resonance Imaging (MRI) often use a target or template volume to facilitate processing, take advantage of prior information, and define a common coordinate system for analysis. In the neuroimaging literature, the MNI305 Talairach-like coordinate system is often used as a standard template. However, when studying pediatric populations, variation from the adult brain makes the MNI305 suboptimal for processing brain images of children. Morphological changes occurring during development render the use of age-appropriate templates desirable to reduce potential errors and minimize bias during processing of pediatric data. This paper presents the methods used to create unbiased, age-appropriate MRI atlas templates for pediatric studies that represent the average anatomy for the age range of 4.5–18.5 years, while maintaining a high level of anatomical detail and contrast. The creation of anatomical T1-weighted, T2-weighted, and proton density-weighted templates for specific developmentally important age-ranges, used data derived from the largest epidemiological, representative (healthy and normal) sample of the U.S. population, where each subject was carefully screened for medical and psychiatric factors and characterized using established neuropsychological and behavioral assessments. . Use of these age-specific templates was evaluated by computing average tissue maps for gray matter, white matter, and cerebrospinal fluid for each specific age range, and by conducting an exemplar voxel-wise deformation-based morphometry study using 66 young (4.5–6.9 years) participants to demonstrate the benefits of using the age-appropriate templates. The public availability of these atlases/templates will facilitate analysis of pediatric MRI data and enable comparison of results between studies in a common standardized space specific to pediatric research. PMID:20656036

  9. Cheaters in mutualism networks.

    PubMed

    Genini, Julieta; Morellato, L Patrícia C; Guimarães, Paulo R; Olesen, Jens M

    2010-08-23

    Mutualism-network studies assume that all interacting species are mutualistic partners and consider that all links are of one kind. However, the influence of different types of links, such as cheating links, on network organization remains unexplored. We studied two flower-visitation networks (Malpighiaceae and Bignoniaceae and their flower visitors), and divide the types of link into cheaters (i.e. robbers and thieves of flower rewards) and effective pollinators. We investigated if there were topological differences among networks with and without cheaters, especially with respect to nestedness and modularity. The Malpighiaceae network was nested, but not modular, and it was dominated by pollinators and had much fewer cheater species than Bignoniaceae network (28% versus 75%). The Bignoniaceae network was mainly a plant-cheater network, being modular because of the presence of pollen robbers and showing no nestedness. In the Malpighiaceae network, removal of cheaters had no major consequences for topology. In contrast, removal of cheaters broke down the modularity of the Bignoniaceae network. As cheaters are ubiquitous in all mutualisms, the results presented here show that they have a strong impact upon network topology.

  10. 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.

  11. 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

  12. 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

  13. Self-consistent, unbiased root-mean-square emittance analysis

    NASA Astrophysics Data System (ADS)

    Stockli, Martin P.; Welton, R. F.; Keller, R.

    2004-05-01

    We present a self-consistent method for analyzing measured emittance data that yields unbiased estimates for the root-mean-square (rms) emittance. The self-consistent, unbiased elliptical exclusion analysis uses an ellipse to determine the bias from the data outside the ellipse, before calculating the rms emittance from the bias-subtracted data within the ellipse. Increasing the ellipse size until the rms emittance estimate saturates allows for determining the minimum elliptical area that includes all real signals, even those buried in the noise. Variations of the ellipse shape and orientations are used to test the robustness of the results. Background fluctuations cause fluctuations in the rms emittance estimate, which are an estimate of the uncertainty incurred through the analysis.

  14. 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

  15. 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.

  16. 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

    ... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual...

  17. 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

    ... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual...

  18. 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

    ... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual...

  19. 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

    ... Companies § 1.831-3 Tax on insurance companies (other than life or mutual), mutual marine insurance... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Tax on insurance companies (other than life or mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual...

  20. 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 mutual), mutual marine insurance companies, mutual fire insurance companies issuing perpetual policies...-3 Tax on insurance companies (other than life or mutual), mutual marine insurance companies,...

  1. Mutually temporally independent connectivity patterns: A new framework to study resting state brain dynamics with application to explain group difference based on gender

    PubMed Central

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

    2015-01-01

    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

  2. [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

  3. [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.

  4. 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.…

  5. Lightcurve Analysis of an Unbiased Sample of Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Molnar, Lawrence A.; Haegert, Melissa, J.; Hoogeboom, Kathleen M.

    2008-06-01

    Lightcurve observations of ten Trojan asteroids made at the Calvin Observatory are reported: 1143 Odysseus, 1208 Troilus, 2920 Automedon, 3709 Polypoites, 5144 Achates, 5638 Deikoon, (7352) 1994 CO, (34746) 2001 QE91, (38050) 1998 VR38, and (48438) 1989 WJ2. Synodic rotation periods were determined for all but (7352) 1994 CO, which showed no significant variation. The sample was unbiased with regard to period, and has a median value, 18.9 hours, significantly longer than for similarly sized main-belt objects. This may be evidence for a lower average mass density among the Trojans.

  6. Unbiased Estimation of Mutation Rates under Fluctuating Final Counts

    PubMed Central

    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

  7. Construction of the influenza A virus infection-induced cell-specific inflammatory regulatory network based on mutual information and optimization

    PubMed Central

    2013-01-01

    Background Influenza A virus (IAV) infection-induced inflammatory regulatory networks (IRNs) are extremely complex and dynamic. Specific biological experiments for investigating the interactions between individual inflammatory factors cannot provide a detailed and insightful multidimensional view of IRNs. Recently, data from high-throughput technologies have permitted system-level analyses. The construction of large and cell-specific IRNs from high-throughput data is essential to understanding the pathogenesis of IAV infection. Results In this study, we proposed a computational method, which combines nonlinear ordinary differential equation (ODE)-based optimization with mutual information, to construct a cell-specific optimized IRN during IAV infection by integrating gene expression data with a prior knowledge of network topology. Moreover, we used the average relative error and sensitivity analysis to evaluate the effectiveness of our proposed approach. Furthermore, from the optimized IRN, we confirmed 45 interactions between proteins in biological experiments and identified 37 new regulatory interactions and 8 false positive interactions, including the following interactions: IL1β regulates TLR3, TLR3 regulates IFN-β and TNF regulates IL6. Most of these regulatory interactions are statistically significant by Z-statistic. The functional annotations of the optimized IRN demonstrated clearly that the defense response, immune response, response to wounding and regulation of cytokine production are the pivotal processes of IAV-induced inflammatory response. The pathway analysis results from the Kyoto Encyclopaedia of Genes and Genomes (KEGG) showed that 8 pathways are enriched significantly. The 5 pathways were validated by experiments, and 3 other pathways, including the intestinal immune network for IgA production, the cytosolic DNA-sensing pathway and the allograft rejection pathway, are the predicted novel pathways involved in the inflammatory response

  8. 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

  9. Mutual Mentoring Makes Better Mentors

    NASA Astrophysics Data System (ADS)

    Blaha, Cindy; Bug, Amy; Cox, Anne; Fritz, Linda; Whitten, Barbara

    2011-03-01

    In this talk we discuss one of the impacts of an NSF ADVANCE sponsored horizontal, mutual mentoring alliance. Our cohort of five women physicists at liberal arts colleges has found that mutual mentoring has had a profound impact on many aspects of our professional lives. In this talk we will describe how our peer-to-peer mentoring has enabled us to become better mentors for our undergraduate students, for recent graduates beginning their careers and for colleagues at local and neighboring institutions.

  10. 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.

  11. Reducing Deviance Through Youths' Mutual Aid Group Dynamics.

    PubMed

    Cheung, Chau-kiu; Ngai, Steven Sek-yum

    2016-01-01

    The mutual aid group, as supported by the social worker, emerges to play a vital role in helping group members reduce their deviance or behavioral problem. However, how the collaboration of the group and social worker accomplishes the reduction has remained uncharted. Based on social capital theory, mutual aid and cohesion within the group and social workers' specific aid for the group are likely responsible for the reduction. The test of such hypotheses relies on a two-wave panel survey of the members of 60 mutual aid groups who had deviant behavioral problems, located in Hong Kong, China. These groups had 241 youths completing both initial and 1-year follow-up surveys. Results manifested the direct or unconditional contributions of mutual aid, group cohesion, and social workers' specific aid to reducing deviance. Hence, social workers can enhance the effectiveness of the mutual aid group in reducing youths' deviance.

  12. An unbiased pilot survey for Galactic water masers

    NASA Astrophysics Data System (ADS)

    Caswell, J. L.; Breen, S. L.

    2010-10-01

    The Australia Telescope Compact Array has been used in a fast surveying mode to study the 22-GHz transition of water in two small sample regions of the southern Galactic plane. The observations allow an unbiased search for water masers, including any that may have no association with masers from other molecules (or indeed, no association with any other detectable celestial object). Positions with arcsecond accuracy were obtained from the original survey data for detected sources, and these were re-observed at an epoch more than two years later. Variability of the spectra between the epochs was considerable: our total of 32 masers comprises 24 detected at both epochs, two detected at only the first epoch and six detected at only the follow-up epoch. The success of our surveying mode shows it to be a practical strategy for the difficult task of extending unbiased water maser surveys to a large portion of the Galactic plane. Our results show quantitatively the effect of variability on the completeness of surveys conducted at a single epoch. Most of our maser detections are new discoveries. Only four had previously been detected (in searches towards interesting targets in the survey area). The high density of water masers from our unbiased survey supports earlier suggestions that they are the most populous maser species, and one of the most sensitive and reliable tracers of massive young stellar objects - newly forming massive young stars. The spectra of nine masers show high-velocity emission, and they show a striking preponderance of blueshifted high-velocity features. This is compatible with such blueshifts being a characteristic of populations dominated by masers at the earliest evolutionary stage of star formation, in some cases prior to the onset of methanol masers. Amongst the high-velocity emission sources there are two new examples where blueshifted high-velocity outflows dominate the total emission; these substantially increase the previously known meagre

  13. 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.

  14. 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.

  15. Sequence comparisons via algorithmic mutual information.

    PubMed

    Milosavljević, A

    1994-01-01

    One of the main problems in DNA and protein sequence comparisons is to decide whether observed similarity of two sequences should be explained by their relatedness or by mere presence of some shared internal structure, e.g., shared internal tandem repeats. The standard methods that are based on statistics or classical information theory can be used to discover either internal structure or mutual sequence similarity, but cannot take into account both. Consequently, currently used methods for sequence comparison employ "masking" techniques that simply eliminate sequences that exhibit internal repetitive structure prior to sequence comparisons. The "masking" approach precludes discovery of homologous sequences of moderate or low complexity, which abound at both DNA and protein levels. As a solution to this problem, we propose a general method that is based on algorithmic information theory and minimal length encoding. We show that algorithmic mutual information factors out the sequence similarity that is due to shared internal structure and thus enables discovery of truly related sequences. We extend that recently developed algorithmic significance method (Milosavljević & Jurka 1993) to show that significance depends exponentially on algorithmic mutual information.

  16. Insights from WISP, an Unbiased Search for Distant Emission-line Galaxies

    NASA Astrophysics Data System (ADS)

    Malkan, M.; WISP Team

    2013-10-01

    The search for true physical pairs of galaxies at high redshifts has been greatly hindered by the difficulty of obtaining good spectroscopic redshifts. Multi-object near-infrared spectroscopy is especially effective, since it reaches the strongest rest-frame spectral features, especially emission lines. From ground-based telescopes, this is still very difficult to obtain for faint galaxies. However, the near-IR grism spectrographs on Hubble Space Telescope are ideal for a large, unbiased survey for galaxy groups and pairs. Without any pre-selection based on continuum properties, slitless spectroscopic surveys are extremely effective at uncovering large numbers of extreme dwarf galaxies, with very high specific star formation rates, and very low metallicities. We discuss preliminary results on pairs and other properties of galaxies found in the most ambitious of these surveys, the WFC-3 Infrared Spectroscopic Parallels (WISP).

  17. 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.

  18. Implant positioning system using mutual inductance.

    PubMed

    Zou, You; O'Driscoll, Stephen

    2012-01-01

    Surgical placement of implantable medical devices (IMDs) has limited precision and post-implantation the device can move over time. Accurate knowledge of the position of IMDs allows better interpretation of data gathered by the devices and may allow wireless power to be focused on the IMD thereby increasing power transfer efficiency. Existing positioning methods require device sizes and/or power consumptions which exceed the limits of in-vivo mm-sized IMDs applications. This paper describes a novel implant positioning system which replaces the external transmitting (TX) coil of a wireless power transfer link by an array of smaller coils, measures the mutual inductance between each coil in the TX array and the implanted receiving (RX) coil, and uses the spatial variation in those mutual inductances to estimate the location of the implanted device. This method does not increase the hardware or power consumption in the IMD. Mathematical analysis and electromagnetic simulations are presented which explain the theory underlying this scheme and show its feasibility. A particle swarm based algorithm is used to estimate the position of the RX coil from the measured mutual inductance values. MATLAB simulations show the positioning estimation accuracy on the order of 1 mm.

  19. 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…

  20. CIRI: an efficient and unbiased algorithm for de novo circular RNA identification.

    PubMed

    Gao, Yuan; Wang, Jinfeng; Zhao, Fangqing

    2015-01-01

    Recent studies reveal that circular RNAs (circRNAs) are a novel class of abundant, stable and ubiquitous noncoding RNA molecules in animals. Comprehensive detection of circRNAs from high-throughput transcriptome data is an initial and crucial step to study their biogenesis and function. Here, we present a novel chiastic clipping signal-based algorithm, CIRI, to unbiasedly and accurately detect circRNAs from transcriptome data by employing multiple filtration strategies. By applying CIRI to ENCODE RNA-seq data, we for the first time identify and experimentally validate the prevalence of intronic/intergenic circRNAs as well as fragments specific to them in the human transcriptome. PMID:25583365

  1. IRS spectroscopy of a complete, unbiased sample of submm galaxies

    NASA Astrophysics Data System (ADS)

    Carilli, Chris; Aguirre, James; Aravena, Manuel; Aussel, Herve; Bertoldi, Frank; Sanders, Dave; Schinnerer, Eva; Scoville, Nick; Sheth, Kartik

    2008-03-01

    We propose 51.5 hours of IRS spectroscopy of a complete, luminosity limited sample of 12 submm galaxies detected at high significance at 250 GHz (> 5sigma) in the Cosmos field. These observations will address two fundamental questions concerning the submm galaxies: (i) do starbursts dominate the energetics of these systems, and if so, how do the physical conditions compare to lower z, lower luminosity starbursts?, and (ii) is there a substantial (up to 30%) high redshift tail (z > 3.6) of hyper-luminous IR galaxies? Such a high redshift tail provides key leverage into models of massive galaxy formation in the early universe. A major legacy of Spitzer has been the demonstration that accurate redshifts for distant, luminous, dust-obscured star forming galaxies can be derived from the PAH features, in addition to the important physical diagnostics on dust heating and composition that come from such spectra. Observing the high S/N, unbiased Cosmos/MAMBO sample will complete this legacy, and test the theory that submm galaxies represent the formation of large elliptical galaxies in massive, dusty starbursts in dense environments at high redshift.

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

    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 and (iii) debiasing the resulting estimates. For (i), we show that removing the best-fitting 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 (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.

  3. 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.

  4. Unbiased Quantitative Models of Protein Translation Derived from Ribosome Profiling Data

    PubMed Central

    Gritsenko, Alexey A.; Hulsman, Marc; Reinders, Marcel J. T.; de Ridder, Dick

    2015-01-01

    Translation of RNA to protein is a core process for any living organism. While for some steps of this process the effect on protein production is understood, a holistic understanding of translation still remains elusive. In silico modelling is a promising approach for elucidating the process of protein synthesis. Although a number of computational models of the process have been proposed, their application is limited by the assumptions they make. Ribosome profiling (RP), a relatively new sequencing-based technique capable of recording snapshots of the locations of actively translating ribosomes, is a promising source of information for deriving unbiased data-driven translation models. However, quantitative analysis of RP data is challenging due to high measurement variance and the inability to discriminate between the number of ribosomes measured on a gene and their speed of translation. We propose a solution in the form of a novel multi-scale interpretation of RP data that allows for deriving models with translation dynamics extracted from the snapshots. We demonstrate the usefulness of this approach by simultaneously determining for the first time per-codon translation elongation and per-gene translation initiation rates of Saccharomyces cerevisiae from RP data for two versions of the Totally Asymmetric Exclusion Process (TASEP) model of translation. We do this in an unbiased fashion, by fitting the models using only RP data with a novel optimization scheme based on Monte Carlo simulation to keep the problem tractable. The fitted models match the data significantly better than existing models and their predictions show better agreement with several independent protein abundance datasets than existing models. Results additionally indicate that the tRNA pool adaptation hypothesis is incomplete, with evidence suggesting that tRNA post-transcriptional modifications and codon context may play a role in determining codon elongation rates. PMID:26275099

  5. 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.

  6. Mutuality in the provision of Scottish healthcare.

    PubMed

    Howieson, Brian

    2015-11-01

    The backdrop to this article is provided by the Better Health, Better Care Action Plan (Scottish Government, 2007), Section 1 of which is entitled 'Towards a Mutual NHS'. According to Better Health, Better Care (Scottish Government, 2007: 5): 'Mutual organisations are designed to serve their members. They are designed to gather people around a common sense of purpose. They are designed to bring the organisation together in what people often call "co-production."' The aim of this article is to précis the current knowledge of mutuality in the provision of Scottish healthcare. In detail, it will: introduce the 'mutual' organisation; offer a historical perspective of mutuality; suggest why healthcare mutuality is important; and briefly, detail the differences in mutual health-care policy in England and Scotland. It is hoped that this analysis will help researchers and practitioners alike appreciate further the philosophy of mutuality in the provision of Scottish healthcare.

  7. Testing assumptions for unbiased estimation of survival of radiomarked harlequin ducks

    USGS Publications Warehouse

    Esler, Daniel; Mulcahy, D.M.; Jarvis, R.L.

    2000-01-01

    Unbiased estimates of survival based on individuals outfitted with radiotransmitters require meeting the assumptions that radios do not affect survival, and animals for which the radio signal is lost have the same survival probability as those for which fate is known. In most survival studies, researchers have made these assumptions without testing their validity. We tested these assumptions by comparing interannual recapture rates (and, by inference, survival) between radioed and unradioed adult female harlequin ducks (Histrionicus histrionicus), and for radioed females, between right-censored birds (i.e., those for which the radio signal was lost during the telemetry monitoring period) and birds with known fates. We found that recapture rates of birds equipped with implanted radiotransmitters (21.6 ?? 3.0%; x?? ?? SE) were similar to unradioed birds (21.7 ?? 8.6%), suggesting that radios did not affect survival. Recapture rates also were similar between right-censored (20.6 ?? 5.1%) and known-fate individuals (22.1 ?? 3.8%), suggesting that missing birds were not subject to differential mortality. We also determined that capture and handling resulted in short-term loss of body mass for both radioed and unradioed females and that this effect was more pronounced for radioed birds (the difference between groups was 15.4 ?? 7.1 g). However, no difference existed in body mass after recapture 1 year later. Our study suggests that implanted radios are an unbiased method for estimating survival of harlequin ducks and likely other species under similar circumstances.

  8. 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

  9. Mutual coupling between rectangular microstrip patch antennas

    NASA Technical Reports Server (NTRS)

    Huynh, Tan; Lee, Kai-Fong; Chebolu, Siva R.; Lee, R. Q.

    1992-01-01

    The paper presents a comprehensive study of the mutual coupling between two rectangular microstrip patch antennas. The cavity model is employed to give numerical results for both mutual impedance and mutual coupling parameters for the E-plane, H-plane, diagonal, and perpendicular orientations. The effects of substrate thickness, substrate permittivity, and feed positions are discussed.

  10. 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...

  11. 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... 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...

  12. 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.

  13. Minimax mutual information approach for independent component analysis.

    PubMed

    Erdogmus, Deniz; Hild, Kenneth E; Rao, Yadunandana N; Príncipe, Joséc C

    2004-06-01

    Minimum output mutual information is regarded as a natural criterion for independent component analysis (ICA) and is used as the performance measure in many ICA algorithms. Two common approaches in information-theoretic ICA algorithms are minimum mutual information and maximum output entropy approaches. In the former approach, we substitute some form of probability density function (pdf) estimate into the mutual information expression, and in the latter we incorporate the source pdf assumption in the algorithm through the use of nonlinearities matched to the corresponding cumulative density functions (cdf). Alternative solutions to ICA use higher-order cumulant-based optimization criteria, which are related to either one of these approaches through truncated series approximations for densities. In this article, we propose a new ICA algorithm motivated by the maximum entropy principle (for estimating signal distributions). The optimality criterion is the minimum output mutual information, where the estimated pdfs are from the exponential family and are approximate solutions to a constrained entropy maximization problem. This approach yields an upper bound for the actual mutual information of the output signals - hence, the name minimax mutual information ICA algorithm. In addition, we demonstrate that for a specific selection of the constraint functions in the maximum entropy density estimation procedure, the algorithm relates strongly to ICA methods using higher-order cumulants. PMID:15130248

  14. Universal model based on the mobile order and disorder theory for predicting lipophilicity and partition coefficients in all mutually immiscible two-phase liquid systems

    PubMed

    Ruelle

    2000-05-01

    The quantitative thermodynamic development of the mobile order and disorder theory in H-bonded liquids has been extended in order to predict partition coefficients. The model enables "a priori" estimation of the partition coefficient (log P) of neutral solutes, not only in the conventional 1-octanol/water reference but also in all mutually saturated two-phase systems made up of largely immiscible solvents. The model is obtained from the thermodynamic treatment of the various physicochemical free energy processes encoded in the overall distribution process and accordingly provides a useful tool for better understanding both the origin and the factors, such as the solute molar volume, that determine the partition coefficient of nonelectrolytes in a given system. From the comparison of the relative magnitude of the processes contributing to the log P value, a lot of information can also be gained regarding the variation in log P of the same substance partitioned between different solvent systems. As a demonstration, the model has been successfully applied to predict the log P of a great number of chemicals of varying structure, size, and chemical nature partitioned in a large set of essentially immiscible solvent pairs, differing either by their nonpolar or by their polar phase. In the systems involving water as the polar phase, the hydrophobic effect is always the driving force that governs the distribution process irrespective of the interacting or noninteracting nature of the substances studied. In the other two-phase systems, the partitioning of complexing solutes in particular appears to be ruled rather by their hydrogen-bonding capabilities than by their hydrophobicities.

  15. Spectroscopic classification of two supernova by NUTS (Nordic Optical Telescope Un-biased Transient Survey)

    NASA Astrophysics Data System (ADS)

    Nielsen, M.; Taddia, F.; Stritzinger, M.; Elias-Rosa, N.; Mattila, S.; Lundqvist, P.; Stritzinger, M.; Kuncarayakti, H.; Harmanen, J.; Pastorello, A.; Benetti, S.; Cappellaro, E.; Blagorodnova, N.; Davis, S.; Dong, S.; Fraser, M.; Gall, C.; Harrison, D.; Hodgkin, S.; Hsiao, E. Y.; Jonker, P.; Kangas, T.; Kankare, E.; Kostrzewa-Rutkowska, Z.; Ochner, P.; Prieto, J. L.; Reynolds, T.; Romero-Canizales, C.; Tartaglia, L.; Terreran, G.; Tomasella, L.; Wyrzykowski, L.

    2016-10-01

    The NOT Unbiased Transient Survey (NUTS; ATel #8992) reports spectroscopic classification of: ASASSN-16lm in 2MASX J09033461+4142367 (Atel# 9611) and Master OT J025606.21+274206.8 in PGC090644 (Atel# 9593).

  16. 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.

  17. The Appropriateness of Unbiased Optical Fractionators to Assess Cell Proliferation in the Adult Hippocampus

    PubMed Central

    Noori, Hamid R.; Fornal, Casimir A.

    2011-01-01

    Optical fractionators have dominated the field of neural cell counting for two decades. These unbiased stereological techniques are often used for the quantification of hippocampal cell proliferation in neurogenesis experiments. However, the heterogeneous distribution of labeled cells, especially in the form of clusters, confounds the application of these techniques. A critical evaluation of the applicability of the optical fractionator suggests that absolute counting achieves higher efficiency in the quantification of cell proliferation than unbiased estimations. PMID:22207833

  18. 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.

  19. 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

  20. Last-passage Monte Carlo algorithm for mutual capacitance.

    PubMed

    Hwang, Chi-Ok; Given, James A

    2006-08-01

    We develop and test the last-passage diffusion algorithm, a charge-based Monte Carlo algorithm, for the mutual capacitance of a system of conductors. The first-passage algorithm is highly efficient because it is charge based and incorporates importance sampling; it averages over the properties of Brownian paths that initiate outside the conductor and terminate on its surface. However, this algorithm does not seem to generalize to mutual capacitance problems. The last-passage algorithm, in a sense, is the time reversal of the first-passage algorithm; it involves averages over particles that initiate on an absorbing surface, leave that surface, and diffuse away to infinity. To validate this algorithm, we calculate the mutual capacitance matrix of the circular-disk parallel-plate capacitor and compare with the known numerical results. Good agreement is obtained.

  1. 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.

  2. 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

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

  3. 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

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

  4. 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

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

  5. Construction of bacteria-eukaryote synthetic mutualism.

    PubMed

    Kubo, Isao; Hosoda, Kazufumi; Suzuki, Shingo; Yamamoto, Kayo; Kihara, Kumiko; Mori, Kotaro; Yomo, Tetsuya

    2013-08-01

    Mutualism is ubiquitous in nature but is known to be intrinsically vulnerable with regard to both population dynamics and evolution. Synthetic ecology has indicated that it is feasible for organisms to establish novel mutualism merely through encountering each other by showing that it is feasible to construct synthetic mutualism between organisms. However, bacteria-eukaryote mutualism, which is ecologically important, has not yet been constructed. In this study, we synthetically constructed mutualism between a bacterium and a eukaryote by using two model organisms. We mixed a bacterium, Escherichia coli (a genetically engineered glutamine auxotroph), and an amoeba, Dictyostelium discoideum, in 14 sets of conditions in which each species could not grow in monoculture but potentially could grow in coculture. Under a single condition in which the bacterium and amoeba mutually compensated for the lack of required nutrients (lipoic acid and glutamine, respectively), both species grew continuously through several subcultures, essentially establishing mutualism. Our results shed light on the establishment of bacteria-eukaryote mutualism and indicate that a bacterium and eukaryote pair in nature also has a non-negligible possibility of establishing novel mutualism if the organisms are potentially mutualistic. PMID:23711432

  6. 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

  7. 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.

  8. Long-range RNA pairings contribute to mutually exclusive splicing.

    PubMed

    Yue, Yuan; Yang, Yun; Dai, Lanzhi; Cao, Guozheng; Chen, Ran; Hong, Weiling; Liu, Baoping; Shi, Yang; Meng, Yijun; Shi, Feng; Xiao, Mu; Jin, Yongfeng

    2016-01-01

    Mutually exclusive splicing is an important means of increasing the protein repertoire, by which the Down's syndrome cell adhesion molecule (Dscam) gene potentially generates 38,016 different isoforms in Drosophila melanogaster. However, the regulatory mechanisms remain obscure due to the complexity of the Dscam exon cluster. Here, we reveal a molecular model for the regulation of the mutually exclusive splicing of the serpent pre-mRNA based on competition between upstream and downstream RNA pairings. Such dual RNA pairings confer fine tuning of the inclusion of alternative exons. Moreover, we demonstrate that the splicing outcome of alternative exons is mediated in relative pairing strength-correlated mode. Combined comparative genomics analysis and experimental evidence revealed similar bidirectional structural architectures in exon clusters 4 and 9 of the Dscam gene. Our findings provide a novel mechanistic framework for the regulation of mutually exclusive splicing and may offer potentially applicable insights into long-range RNA-RNA interactions in gene regulatory networks.

  9. Gender Classification From Face Images Using Mutual Information and Feature Fusion

    NASA Astrophysics Data System (ADS)

    Perez, Claudio; Tapia, Juan; Estévez, Pablo; Held, Claudio

    2012-01-01

    In this article we report a new method for gender classification from frontal face images using feature selection based on mutual information and fusion of features extracted from intensity, shape, texture, and from three different spatial scales. We compare the results of three different mutual information measures: minimum redundancy and maximal relevance (mRMR), normalized mutual information feature selection (NMIFS), and conditional mutual information feature selection (CMIFS). We also show that by fusing features extracted from six different methods we significantly improve the gender classification results relative to those previously published, yielding 99.13% of the gender classification rate on the FERET database.

  10. 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…

  11. 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

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

    PubMed

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

    2016-02-01

    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.

  13. 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

  14. 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

  15. Experimental generation and characterization of single-photon hybrid ququarts based on polarization and orbital angular momentum encoding

    SciTech Connect

    Nagali, Eleonora; Sansoni, Linda; Marrucci, Lorenzo; Santamato, Enrico; Sciarrino, Fabio

    2010-05-15

    High-dimensional quantum states, or qudits, represent a promising resource in the quantum information field. Here we present the experimental generation of four-dimensional quantum states, or ququarts, encoded in the polarization and orbital angular momentum of a single photon. Our technique, based on the q-plate device, allows the ququart to be prepared and measured in all five mutually unbiased bases. We report the reconstruction of the four-dimensional density matrix through the tomographic procedure for different ququart states.

  16. Bright Lights and Questions: Using Mutual Interrogation

    ERIC Educational Resources Information Center

    Adam, Aishikin; Alangui, Willy; Barton, Bill

    2010-01-01

    Mutual Interrogation is a research methodology for ethnomathematics proposed by Alangui in 2006 in an attempt to avoid the potential inequality set up when a restricted cultural practice is viewed through the lens of the near-universal and highly developed research domain of mathematics. Using three significant examples of mutual interrogation in…

  17. Economic contract theory tests models of mutualism

    PubMed Central

    Weyl, E. Glen; Frederickson, Megan E.; Yu, Douglas W.; Pierce, Naomi E.

    2010-01-01

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host–symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume–rhizobia and yucca–moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature. PMID:20733067

  18. 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)

  19. Economic contract theory tests models of mutualism.

    PubMed

    Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

    2010-09-01

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

  20. 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.

  1. Unbiased group-wise image registration: applications in brain fiber tract atlas construction and functional connectivity analysis.

    PubMed

    Geng, Xiujuan; Gu, Hong; Shin, Wanyong; Ross, Thomas J; Yang, Yihong

    2011-10-01

    We propose an unbiased implicit-reference group-wise (IRG) image registration method and demonstrate its applications in the construction of a brain white matter fiber tract atlas and the analysis of resting-state functional MRI (fMRI) connectivity. Most image registration techniques pair-wise align images to a selected reference image and group analyses are performed in the reference space, which may produce bias. The proposed method jointly estimates transformations, with an elastic deformation model, registering all images to an implicit reference corresponding to the group average. The unbiased registration is applied to build a fiber tract atlas by registering a group of diffusion tensor images. Compared to reference-based registration, the IRG registration improves the fiber track overlap within the group. After applying the method in the fMRI connectivity analysis, results suggest a general improvement in functional connectivity maps at a group level in terms of larger cluster size and higher average t-scores.

  2. 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...

  3. The evolution of plant-insect mutualisms.

    PubMed

    Bronstein, Judith L; Alarcón, Ruben; Geber, Monica

    2006-01-01

    Mutualisms (cooperative interactions between species) have had a central role in the generation and maintenance of life on earth. Insects and plants are involved in diverse forms of mutualism. Here we review evolutionary features of three prominent insect-plant mutualisms: pollination, protection and seed dispersal. We focus on addressing five central phenomena: evolutionary origins and maintenance of mutualism; the evolution of mutualistic traits; the evolution of specialization and generalization; coevolutionary processes; and the existence of cheating. Several features uniting very diverse insect-plant mutualisms are identified and their evolutionary implications are discussed: the involvement of one mobile and one sedentary partner; natural selection on plant rewards; the existence of a continuum from specialization to generalization; and the ubiquity of cheating, particularly on the part of insects. Plant-insect mutualisms have apparently both arisen and been lost repeatedly. Many adaptive hypotheses have been proposed to explain these transitions, and it is unlikely that any one of them dominates across interactions differing so widely in natural history. Evolutionary theory has a potentially important, but as yet largely unfilled, role to play in explaining the origins, maintenance, breakdown and evolution of insect-plant mutualisms.

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. 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…

  10. 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…

  11. 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)

  12. 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

  13. 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

  14. Unbiased and mobile gait analysis detects motor impairment in Parkinson's disease.

    PubMed

    Klucken, Jochen; Barth, Jens; Kugler, Patrick; Schlachetzki, Johannes; Henze, Thore; Marxreiter, Franz; Kohl, Zacharias; Steidl, Ralph; Hornegger, Joachim; Eskofier, Bjoern; Winkler, Juergen

    2013-01-01

    Motor impairments are the prerequisite for the diagnosis in Parkinson's disease (PD). The cardinal symptoms (bradykinesia, rigor, tremor, and postural instability) are used for disease staging and assessment of progression. They serve as primary outcome measures for clinical studies aiming at symptomatic and disease modifying interventions. One major caveat of clinical scores such as the Unified Parkinson Disease Rating Scale (UPDRS) or Hoehn&Yahr (H&Y) staging is its rater and time-of-assessment dependency. Thus, we aimed to objectively and automatically classify specific stages and motor signs in PD using a mobile, biosensor based Embedded Gait Analysis using Intelligent Technology (eGaIT). eGaIT consist of accelerometers and gyroscopes attached to shoes that record motion signals during standardized gait and leg function. From sensor signals 694 features were calculated and pattern recognition algorithms were applied to classify PD, H&Y stages, and motor signs correlating to the UPDRS-III motor score in a training cohort of 50 PD patients and 42 age matched controls. Classification results were confirmed in a second independent validation cohort (42 patients, 39 controls). eGaIT was able to successfully distinguish PD patients from controls with an overall classification rate of 81%. Classification accuracy increased with higher levels of motor impairment (91% for more severely affected patients) or more advanced stages of PD (91% for H&Y III patients compared to controls), supporting the PD-specific type of analysis by eGaIT. In addition, eGaIT was able to classify different H&Y stages, or different levels of motor impairment (UPDRS-III). In conclusion, eGaIT as an unbiased, mobile, and automated assessment tool is able to identify PD patients and characterize their motor impairment. It may serve as a complementary mean for the daily clinical workup and support therapeutic decisions throughout the course of the disease. PMID:23431395

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. Unbiased degree-preserving randomization of directed binary networks.

    PubMed

    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.

  20. Unbiased Evaluation of Bioactive Secondary Metabolites in Complex Matrices

    PubMed Central

    Inui, Taichi; Wang, Yuehong; Pro, Samuel M.; Franzblau, Scott G.; Pauli, Guido F.

    2012-01-01

    The majority of bioactive principles in a complex matrix such as natural products and botanical medicines are secondary rather than primary metabolites. In addition to being chemically diverse, the bioactivity of an ethnobotanical can comprise from one to several bioactive compounds, present in a complex mixture. Conventional discovery efforts utilize bioassay-guided fractionation (BGF) to isolate individual active compounds. When applied to complex natural products, BGF is often challenged by an apparent loss of activity during fractionation, resulting in weakly active isolated compounds. Metabolomic analysis can potentially complement existing the BGF paradigm by capturing the chemical complexity of the metabolites. The proposed biochemometric approach establishes a link between the chemistry of a secondary metabolome and a deserved health impact, using a high-throughput, high-resolution capable biological endpoint. The proof of principle is demonstrated for the anti-tuberculosis (TB) activity of the Alaskan ethnobotanical, Oplopanax horridus. Biochemometric analysis identified the 100 most active constituents from thousands of metabolites in the active extract by means of 2D orthogonal chromatography using countercurrent and GC-MS methods. Previously isolated O. horridus phytoconstituents were used as reference markers of known structure and bio(in)activity. Positive correlations allowed distinction of anti-TB actives from inactive compounds. A total of 29 bioactives from 3 main structural classes were assigned based on MS data. Biochemometric analysis is a new tool for the standardization of herbal medicines and ethnobotanicals, as well as for drug discovery from nature. The method can assign multiple active compounds in complex mixtures without their prior isolation or structure elucidation, while still providing an interface to structural information. PMID:22766306

  1. Unbiased identification of patients with disorders of sex development.

    PubMed

    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 result in

  2. 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.

  3. 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

  4. 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...-OPERATIONS Securities and Borrowings § 563.74 Mutual capital certificates. (a) General. No savings association that is in the mutual form shall issue mutual capital certificates pursuant to this section...

  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 544.5 - Federal mutual savings association bylaws.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Federal mutual savings association bylaws. 544... MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Bylaws § 544.5 Federal mutual savings association bylaws. (a) General. A Federal mutual savings association shall operate under bylaws that contain...

  7. 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...

  8. 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... MUTUAL SAVINGS ASSOCIATIONS-CHARTER AND BYLAWS Bylaws § 544.5 Federal mutual savings association bylaws. (a) General. A Federal mutual savings association shall operate under bylaws that contain...

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. Extending the mutual information measure to rank inferred literature relationships

    PubMed Central

    Wren, Jonathan D

    2004-01-01

    Background Within the peer-reviewed literature, associations between two things are not always recognized until commonalities between them become apparent. These commonalities can provide justification for the inference of a new relationship where none was previously known, and are the basis of most observation-based hypothesis formation. It has been shown that the crux of the problem is not finding inferable associations, which are extraordinarily abundant given the scale-free networks that arise from literature-based associations, but determining which ones are informative. The Mutual Information Measure (MIM) is a well-established method to measure how informative an association is, but is limited to direct (i.e. observable) associations. Results Herein, we attempt to extend the calculation of mutual information to indirect (i.e. inferable) associations by using the MIM of shared associations. Objects of general research interest (e.g. genes, diseases, phenotypes, drugs, ontology categories) found within MEDLINE are used to create a network of associations for evaluation. Conclusions Mutual information calculations can be effectively extended into implied relationships and a significance cutoff estimated from analysis of random word networks. Of the models tested, the shared minimum MIM (MMIM) model is found to correlate best with the observed strength and frequency of known associations. Using three test cases, the MMIM method tends to rank more specific relationships higher than counting the number of shared relationships within a network. PMID:15471547

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

    DOE PAGES

    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

  15. 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.

  16. Brain activity: connectivity, sparsity, and mutual information.

    PubMed

    Cassidy, Ben; Rae, Caroline; Solo, Victor

    2015-04-01

    We develop a new approach to functional brain connectivity analysis, which deals with four fundamental aspects of connectivity not previously jointly treated. These are: temporal correlation, spurious spatial correlation, sparsity, and network construction using trajectory (as opposed to marginal) Mutual Information. We call the new method Sparse Conditional Trajectory Mutual Information (SCoTMI). We demonstrate SCoTMI on simulated and real fMRI data, showing that SCoTMI gives more accurate and more repeatable detection of network links than competing network estimation methods.

  17. Mutual Orbits of Transneptunian Multibody Systems

    NASA Astrophysics Data System (ADS)

    Grundy, William

    2014-08-01

    We propose to use LGS AO with NIRC2 during stellar appulses to measure relative astrometry of the large sample of transneptunian binaries for which mutual orbits remain unknown. Our long-term goal is to determine as many of their orbits as possible. These orbits provide a crucial constraint on dynamical conditions in outer parts of the protoplanetary nebula, as well as subsequent outer solar system history. They provide system masses and thus bulk densities, as well as enabling constraint of tidal dissipation parameters, scheduling of mutual event seasons, and revealing possible unresolved n>2 systems.

  18. Impact of Mutual Mentoring on Research

    NASA Astrophysics Data System (ADS)

    Whitten, Barbara; Blaha, Cynthia; Bug, Amy; Cox, Anne; Fritz, Linda

    2011-03-01

    In this talk we discuss one of the impacts of an NSF ADVANCE sponsored horizontal, mutual mentoring alliance. Our cohort of five women physicists at liberal arts colleges has found that mutual mentoring has had a profound impact on many aspects of our professional lives. In this talk we will give some specific ways that we have supported and helped to expand each other's research. For some new areas of research were opened, for others new focus was brought to existing areas, and still others found acceptance for where they were.

  19. 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

    ... 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 foreign... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Tax on insurance companies (other than life...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Mutual Information, Fisher Information, and Efficient Coding.

    PubMed

    Wei, Xue-Xin; Stocker, Alan A

    2016-02-01

    Fisher information is generally believed to represent a lower bound on mutual information (Brunel & Nadal, 1998), a result that is frequently used in the assessment of neural coding efficiency. However, we demonstrate that the relation between these two quantities is more nuanced than previously thought. For example, we find that in the small noise regime, Fisher information actually provides an upper bound on mutual information. Generally our results show that it is more appropriate to consider Fisher information as an approximation rather than a bound on mutual information. We analytically derive the correspondence between the two quantities and the conditions under which the approximation is good. Our results have implications for neural coding theories and the link between neural population coding and psychophysically measurable behavior. Specifically, they allow us to formulate the efficient coding problem of maximizing mutual information between a stimulus variable and the response of a neural population in terms of Fisher information. We derive a signature of efficient coding expressed as the correspondence between the population Fisher information and the distribution of the stimulus variable. The signature is more general than previously proposed solutions that rely on specific assumptions about the neural tuning characteristics. We demonstrate that it can explain measured tuning characteristics of cortical neural populations that do not agree with previous models of efficient coding.

  6. 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…

  7. Empowering Public Welfare Workers through Mutual Support.

    ERIC Educational Resources Information Center

    Sherman, Wendy Ruth; Wenocur, Stanley

    1983-01-01

    Examines the organizational binds facing social workers concerned with the provision of services to clients in times of fiscal restraint. Suggests a mutual support group as a step toward empowerment. Workers may shift from a support group to a coalition for action as change agents within institutional settings. (JAC)

  8. Do Mutual Children Cement Bonds in Stepfamilies?

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn

    1988-01-01

    Interviewed 105 midwestern stepfamilies, 39 of whom had reproduced together. Found no significant differences between families with mutual children and those without in terms of marital adjustment, stepparent- and parent-child relationships, and stepfamily affect. It was not possible to predict which families were most likely to reproduce together…

  9. 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.

  10. 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...

  11. Spectroscopic observation of CSS161010 and SN2016gxp by NUTS (NOT Un-biased Transient Survey)

    NASA Astrophysics Data System (ADS)

    Reynolds, T.; Dong, S.; Fraser, M.; Stritzinger, M.; Mattila, S.; Lundqvist, P.; Elias-Rosa, N.; Harmanen, J.; Kangas, T.; Somero, A.; Kuncarayakti, H.; Taddia, F.

    2016-10-01

    The Nordic Optical Telescope (NOT) Unbiased Transient Survey (NUTS; ATel #8992) reports the spectroscopic classification of the hostless transient CSS161010:045834-081803 and further observation of SN2016gxp in NGC51.

  12. Proposal for a mutual insurance pool for transplant organs.

    PubMed

    Schwindt, R; Vining, A

    1998-10-01

    Over the past decade there have been numerous proposals to use market system incentives to attenuate the persistent shortage of transplantable human organs. While shortages have grown, opposition to market-based solutions has remained adamant. Much of the opposition has focused on monetary incentives. This article explores an alternative--a mutual insurance pool to increase the supply of organs. In the process, criticisms of earlier proposals (specifically the future delivery scheme) are addressed, the operation of an insurance pool is described, and problems associated with insurance markets are identified and addressed. The article concludes that an insurance pool could overcome public and political resistance to more explicit market-based solutions.

  13. The origin of a mutualism: a morphological trait promoting the evolution of ant-aphid mutualisms.

    PubMed

    Shingleton, Alexander W; Stern, David L; Foster, William A

    2005-04-01

    Mutualisms are mutually beneficial interactions between species and are fundamentally important at all levels of biological organization. It is not clear, however, why one species participates in a particular mutualism whereas another does not. Here we show that pre-existing traits can dispose particular species to evolve a mutualistic interaction. Combining morphological, ecological, and behavioral data in a comparative analysis, we show that resource use in Chaitophorus aphids (Hemiptera: Aphididae) modulates the origin of their mutualism with ants. We demonstrate that aphid species that feed on deeper phloem elements have longer mouthparts, that this inhibits their ability to withdraw their mouthparts and escape predators and that, consequently, this increases their need for protection by mutualist ants.

  14. A mutualism-parasitism system modeling host and parasite with mutualism at low density.

    PubMed

    Wang, Yuanshi; Deangelis, Donald L

    2012-04-01

    A mutualism-parasitism system of two species is considered, where mutualism is the dominant interaction when the predators (parasites) are at low density while parasitism is dominant when the predators are at high density. Our aim is to show that mutualism at low density promotes coexistence of the species and leads to high production of the prey (host). The mutualism-parasitism system presented here is a combination of the Lotka-Volterra cooperative model and Lotka-Volterra predator-prey model. By comparing dynamics of this system with those of the Lotka-Volterra predator-prey model, we present the mechanisms by which the mutualism improves the coexistence of the species and production of the prey. Then the parameter space is divided into six regions, which correspond to the four outcomes of mutualism, commensalism, predation/parasitism and neutralism, respectively. When the parameters are varied continuously among the six regions, it is shown that the interaction outcomes of the system transition smoothly among the four outcomes. By comparing the dynamics of the specific system with those of the Lotka-Volterra cooperative model, we show that the parasitism at high density promotes stability of the system. A novel aspect of this paper is the simplicity of the model, which allows rigorous and thorough analysis and transparency of the results.

  15. Regioselective aerobic oxidative Heck reactions with electronically unbiased alkenes: efficient access to α-alkyl vinylarenes.

    PubMed

    Zheng, Changwu; Stahl, Shannon S

    2015-08-18

    Branched-selective oxidative Heck coupling reactions have been developed between arylboronic acids and electronically unbiased terminal alkenes. The reactions exhibit high catalyst-controlled regioselectivity favoring the less common branched isomer. The reactions employ a catalyst composed of Pd(TFA)2/dmphen (TFA = trifluoroacetate, dmphen = 2,9-dimethyl-1,10-phenanthroline) and proceed efficiently at 45-60 °C under 1 atm of O2 without requiring other additives. A broad array of functional groups, including aryl halide, allyl silane and carboxylic acids are tolerated.

  16. 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.

  17. Hardware device binding and mutual authentication

    DOEpatents

    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.

  18. 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.

  19. 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.

  20. Trading public goods stabilizes interspecific mutualism.

    PubMed

    Archetti, Marco; Scheuring, István

    2013-02-01

    The existence of cooperation between species raises a fundamental problem for evolutionary theory. Why provide costly services to another species if the feedback of this provision also happens to benefit intra-specific competitors that provide no service? Rewarding cooperators and punishing defectors can help maintain mutualism; this is not possible, however, when one can only respond to the collective action of one's partners, which is likely to be the case in many common symbioses. We show how the theory of public goods can explain the stability of mutualism when discrimination between cooperators and defectors is not possible: if two groups of individuals trade goods that are non-linear, increasing functions of the number of contributions, their mutualistic interaction is maintained by the exchange of these public goods, even when it is not possible to punish defectors, which can persist at relatively high frequencies. This provides a theoretical justification and testable predictions for the evolution of mutualism in the absence of discrimination mechanisms.

  1. 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.

  2. Cheating and the evolutionary stability of mutualisms.

    PubMed

    Ferriere, Régis; Bronstein, Judith L; Rinaldi, Sergio; Law, Richard; Gauduchon, Mathias

    2002-04-22

    Interspecific mutualisms have been playing a central role in the functioning of all ecosystems since the early history of life. Yet the theory of coevolution of mutualists is virtually nonexistent, by contrast with well-developed coevolutionary theories of competition, predator-prey and host-parasite interactions. This has prevented resolution of a basic puzzle posed by mutualisms: their persistence in spite of apparent evolutionary instability. The selective advantage of 'cheating', that is, reaping mutualistic benefits while providing fewer commodities to the partner species, is commonly believed to erode a mutualistic interaction, leading to its dissolution or reciprocal extinction. However, recent empirical findings indicate that stable associations of mutualists and cheaters have existed over long evolutionary periods. Here, we show that asymmetrical competition within species for the commodities offered by mutualistic partners provides a simple and testable ecological mechanism that can account for the long-term persistence of mutualisms. Cheating, in effect, establishes a background against which better mutualists can display any competitive superiority. This can lead to the coexistence and divergence of mutualist and cheater phenotypes, as well as to the coexistence of ecologically similar, but unrelated mutualists and cheaters.

  3. MISTIC: Mutual information server to infer coevolution.

    PubMed

    Simonetti, Franco L; Teppa, Elin; Chernomoretz, Ariel; Nielsen, Morten; Marino Buslje, Cristina

    2013-07-01

    MISTIC (mutual information server to infer coevolution) is a web server for graphical representation of the information contained within a MSA (multiple sequence alignment) and a complete analysis tool for Mutual Information networks in protein families. The server outputs a graphical visualization of several information-related quantities using a circos representation. This provides an integrated view of the MSA in terms of (i) the mutual information (MI) between residue pairs, (ii) sequence conservation and (iii) the residue cumulative and proximity MI scores. Further, an interactive interface to explore and characterize the MI network is provided. Several tools are offered for selecting subsets of nodes from the network for visualization. Node coloring can be set to match different attributes, such as conservation, cumulative MI, proximity MI and secondary structure. Finally, a zip file containing all results can be downloaded. The server is available at http://mistic.leloir.org.ar. In summary, MISTIC allows for a comprehensive, compact, visually rich view of the information contained within an MSA in a manner unique to any other publicly available web server. In particular, the use of circos representation of MI networks and the visualization of the cumulative MI and proximity MI concepts is novel.

  4. 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

  5. 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

  6. Experimental strategies for functional annotation and metabolism discovery: targeted screening of solute binding proteins and unbiased panning of metabolomes.

    PubMed

    Vetting, Matthew W; Al-Obaidi, Nawar; Zhao, Suwen; San Francisco, Brian; Kim, Jungwook; Wichelecki, Daniel J; Bouvier, Jason T; Solbiati, Jose O; Vu, Hoan; Zhang, Xinshuai; Rodionov, Dmitry A; Love, James D; Hillerich, Brandan S; Seidel, Ronald D; Quinn, Ronald J; Osterman, Andrei L; Cronan, John E; Jacobson, Matthew P; Gerlt, John A; Almo, Steven C

    2015-01-27

    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.

  7. 29 CFR 553.105 - Mutual aid agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Mutual aid agreements. 553.105 Section 553.105 Labor... Mutual aid agreements. An agreement between two or more States, political subdivisions, or interstate governmental agencies for mutual aid does not change the otherwise volunteer character of services performed...

  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. 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...

  12. 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...

  13. 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.

  14. 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.

  15. 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

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

    PubMed

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

    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

  17. 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

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

    PubMed

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

    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

  19. Identification of lipid-phosphatidylserine (PS) as the target of unbiasedly selected cancer specific peptide-peptoid hybrid PPS1

    PubMed Central

    Desai, Tanvi J.; Toombs, Jason E.; Minna, John D.; Brekken, Rolf A.; Udugamasooriya, Damith Gomika

    2016-01-01

    Phosphatidylserine (PS) is an anionic phospholipid maintained on the inner-leaflet of the cell membrane and is externalized in malignant cells. We previously launched a careful unbiased selection targeting biomolecules (e.g. protein, lipid or carbohydrate) distinct to cancer cells by exploiting HCC4017 lung cancer and HBEC30KT normal epithelial cells derived from the same patient, identifying HCC4017 specific peptide-peptoid hybrid PPS1. In this current study, we identified PS as the target of PPS1. We validated direct PPS1 binding to PS using ELISA-like assays, lipid dot blot and liposome based binding assays. In addition, PPS1 recognized other negatively charged and cancer specific lipids such as phosphatidic acid, phosphatidylinositol and phosphatidylglycerol. PPS1 did not bind to neutral lipids such as phosphatidylethanolamine found in cancer and phosphatidylcholine and sphingomyelin found in normal cells. Further we found that the dimeric version of PPS1 (PPS1D1) displayed strong cytotoxicity towards lung cancer cell lines that externalize PS, but not normal cells. PPS1D1 showed potent single agent anti-tumor activity and enhanced the efficacy of docetaxel in mice bearing H460 lung cancer xenografts. Since PS and anionic phospholipid externalization is common across many cancer types, PPS1 may be an alternative to overcome limitations of protein targeted agents. PMID:27120792

  20. White matter microstructural characteristics in newly diagnosed Parkinson’s disease: An unbiased whole-brain study

    PubMed Central

    Wen, Ming-Ching; Heng, Hannah S. E.; Ng, Samuel Y. E.; Tan, Louis C. S.; Chan, Ling Ling; Tan, Eng King

    2016-01-01

    Parkinson’s disease (PD) is a debilitating neurodegenerative disorder. Findings on specific white matter (WM) alterations in PD have been inconsistent. We hypothesized that WM changes occur in early PD patients and unbiased whole-brain analysis may provide additional evidence of pathological WM changes in PD. In this study, we examined various indexes of WM microstructure in newly diagnosed PD patients at the whole-brain level. 64 PDs with Hoehn & Yahr stage 1 (HY1PDs), 87 PDs with Hoehn & Yahr stage 2 (HYPD2s), and 60 controls (HCs) were recruited. Tract-based spatial statistics (TBSS) and diffusion connectometry were used to identify changes of WM pathways associated with PD. There were no significant differences in axial diffusivity, but HY1PDs exhibited greater fractional anisotropy (FA) and decreased mean and radial diffusivities (MD and RD) in callosal, projection, and association fibres than HCs and HY2PDs. Motor severity was inversely correlated with FA, but positively correlated with MD and RD in PD patients. Connectometry analysis also revealed increased WM density in the aforementioned tracts in PD patients, compared with HCs. Our study reveals WM enhancement, suggesting neural compensations in early PD. Longitudinal follow-up studies are warranted to identify the trajectory of WM changes alongside the progression of PD. PMID:27762307

  1. 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

  2. Compositional genomes: prebiotic information transfer in mutually catalytic noncovalent assemblies.

    PubMed

    Segré, D; Ben-Eli, D; Lancet, D

    2000-04-11

    Mutually catalytic sets of simple organic molecules have been suggested to be capable of self-replication and rudimentary chemical evolution. Previous models for the behavior of such sets have analyzed the global properties of short biopolymer ensembles by using graph theory and a mean field approach. In parallel, experimental studies with the autocatalytic formation of amphiphilic assemblies (e.g., lipid vesicles or micelles) demonstrated self-replication properties resembling those of living cells. Combining these approaches, we analyze here the kinetic behavior of small heterogeneous assemblies of spontaneously aggregating molecules, of the type that could form readily under prebiotic conditions. A statistical formalism for mutual rate enhancement is used to numerically simulate the detailed chemical kinetics within such assemblies. We demonstrate that a straightforward set of assumptions about kinetically enhanced recruitment of simple amphiphilic molecules, as well as about the spontaneous growth and splitting of assemblies, results in a complex population behavior. The assemblies manifest a significant degree of homeostasis, resembling the previously predicted quasi-stationary states of biopolymer ensembles (Dyson, F. J. (1982) J. Mol. Evol. 18, 344-350). Such emergent catalysis-driven, compositionally biased entities may be viewed as having rudimentary "compositional genomes." Our analysis addresses the question of how mutually catalytic metabolic networks, devoid of sequence-based biopolymers, could exhibit transfer of chemical information and might undergo selection and evolution. This computed behavior may constitute a demonstration of natural selection in populations of molecules without genetic apparatus, suggesting a pathway from random molecular assemblies to a minimal protocell. PMID:10760281

  3. Compositional genomes: Prebiotic information transfer in mutually catalytic noncovalent assemblies

    PubMed Central

    Segré, Daniel; Ben-Eli, Dafna; Lancet, Doron

    2000-01-01

    Mutually catalytic sets of simple organic molecules have been suggested to be capable of self-replication and rudimentary chemical evolution. Previous models for the behavior of such sets have analyzed the global properties of short biopolymer ensembles by using graph theory and a mean field approach. In parallel, experimental studies with the autocatalytic formation of amphiphilic assemblies (e.g., lipid vesicles or micelles) demonstrated self-replication properties resembling those of living cells. Combining these approaches, we analyze here the kinetic behavior of small heterogeneous assemblies of spontaneously aggregating molecules, of the type that could form readily under prebiotic conditions. A statistical formalism for mutual rate enhancement is used to numerically simulate the detailed chemical kinetics within such assemblies. We demonstrate that a straightforward set of assumptions about kinetically enhanced recruitment of simple amphiphilic molecules, as well as about the spontaneous growth and splitting of assemblies, results in a complex population behavior. The assemblies manifest a significant degree of homeostasis, resembling the previously predicted quasi-stationary states of biopolymer ensembles (Dyson, F. J. (1982) J. Mol. Evol. 18, 344–350). Such emergent catalysis-driven, compositionally biased entities may be viewed as having rudimentary “compositional genomes.” Our analysis addresses the question of how mutually catalytic metabolic networks, devoid of sequence-based biopolymers, could exhibit transfer of chemical information and might undergo selection and evolution. This computed behavior may constitute a demonstration of natural selection in populations of molecules without genetic apparatus, suggesting a pathway from random molecular assemblies to a minimal protocell. PMID:10760281

  4. The role of referent and expert power in mutual help.

    PubMed

    Salem, D A; Reischl, T M; Gallacher, F; Randall, K W

    2000-06-01

    This study explored the roles of referent power (i.e., influence based on sense of identification) and expert power (i.e., influence based on knowledge and expertise) in Schizophrenics Anonymous (SA), a mutual-help group for persons experiencing a schizophrenia-related illness. The study describes SA participants' experience of referent and expert power with SA members, SA leaders, and with mental health professionals. It also examines whether or not referent and expert power ascribed to fellow SA participants predicts the perceived helpfulness of the group. One hundred fifty-six SA participants were surveyed. Participants reported experiencing higher levels of referent power with fellow SA members and leaders than with mental health professionals. They reported higher levels of expert power for mental health professionals and SA leaders than for SA members. The respondents' ratings of their SA group's helpfulness was significantly correlated with ratings of referent and expert power. Although expert power was the best independent predictor of helpfulness, a significant interaction between referent and expert power indicated that when members reported high referent power, expert power was not related to helpfulness. These results are interpreted to suggest that there are multiple forms of social influence at work in mutual help.

  5. Creating a culture of mutual respect.

    PubMed

    Kaplan, Kathryn; Mestel, Pamela; Feldman, David L

    2010-04-01

    The Joint Commission mandates that hospitals seeking accreditation have a process to define and address disruptive behavior. Leaders at Maimonides Medical Center, Brooklyn, New York, took the initiative to create a code of mutual respect that not only requires respectful behavior, but also encourages sensitivity and awareness to the causes of frustration that often lead to inappropriate behavior. Steps to implementing the code included selecting code advocates, setting up a system for mediating disputes, tracking and addressing operational system issues, providing training for personnel, developing a formal accountability process, and measuring the results. PMID:20362215

  6. Mutual obligation, shared responsibility agreements & indigenous health strategy

    PubMed Central

    Anderson, Ian PS

    2006-01-01

    Since 2004 the Howard Coalition government has implemented a new policy framework and administrative arrangements as part of its program of reform in Indigenous affairs. In this paper I will describe both the parameters of this reform program and review the processes established to support the implementation of national Indigenous health strategy. In particular, I will consider both the shift from a policy framework based on 'self-determination' to one based on 'mutual obligation', and the implementation of Shared Responsibility Agreements (SRAs) that are based on the latter principle. I will use the example of the Mulan SRA to illustrate the difficulties in articulating the 'new arrangements' with current approaches to Indigenous health planning and strategy implementation. I conclude that 'new arrangements' pose a number of problems for Indigenous health planning and strategy that need to be addressed. PMID:16999873

  7. Technical note: Estimating unbiased transfer-function performances in spatially structured environments

    NASA Astrophysics Data System (ADS)

    Trachsel, Mathias; Telford, Richard J.

    2016-05-01

    Conventional cross validation schemes for assessing transfer-function performance assume that observations are independent. In spatially structured environments this assumption is violated, resulting in over-optimistic estimates of transfer-function performance. H-block cross validation, where all samples within h kilometres of the test samples are omitted, is a method for obtaining unbiased transfer-function performance estimates. In this study, we assess three methods for determining the optimal h. Using simulated data, we find that all three methods result in comparable values of h. Applying the three methods to published transfer functions, we find they yield similar values for h. Some transfer functions perform notably worse when h-block cross validation is used.

  8. Technical Note: Estimating unbiased transfer-function performances in spatially structured environments

    NASA Astrophysics Data System (ADS)

    Trachsel, M.; Telford, R. J.

    2015-10-01

    Conventional cross-validation schemes for assessing transfer-function performance assume that observations are independent. In spatially-structured environments this assumption is violated, resulting in over-optimistic estimates of transfer-function performance. H block cross-validation, where all samples within h km of the test samples are omitted is a method for obtaining unbiased transfer function performance estimates. In this study, we assess three methods for determining the optimal h. Using simulated data, we find that all three methods result in comparable values of h. Applying the three methods to published transfer functions, we find they yield similar values for h. Some transfer functions perform notably worse when h block cross-validation is used.

  9. Motor activity as an unbiased variable to assess anaphylaxis in allergic rats

    PubMed Central

    Abril-Gil, Mar; Garcia-Just, Alba; Cambras, Trinitat; Pérez-Cano, Francisco J; Castellote, Cristina; Franch, Àngels

    2015-01-01

    The release of mediators by mast cells triggers allergic symptoms involving various physiological systems and, in the most severe cases, the development of anaphylactic shock compromising mainly the nervous and cardiovascular systems. We aimed to establish variables to objectively study the anaphylactic response (AR) after an oral challenge in an allergy model. Brown Norway rats were immunized by intraperitoneal injection of ovalbumin with alum and toxin from Bordetella pertussis. Specific immunoglobulin (Ig) E antibodies were developed in immunized animals. Forty days after immunization, the rats were orally challenged with the allergen, and motor activity, body temperature and serum mast cell protease concentration were determined. The anaphylaxis induced a reduction in body temperature and a decrease in the number of animal movements, which was inversely correlated with serum mast cell protease release. In summary, motor activity is a reliable tool for assessing AR and also an unbiased method for screening new anti-allergic drugs. PMID:25716015

  10. 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.

  11. Operation of the SUPARAMP at 33 GHz. [Superconducting Unbiased PARametric AMPlifier

    NASA Technical Reports Server (NTRS)

    Chiao, R. Y.; Parrish, P. T.

    1976-01-01

    A 9-mm degenerate parametric amplifier has been constructed using a linear series array of unbiased Josephson junctions as the active nonlinear element. A balanced diode mixer was used as a synchronous detector, with a single source serving both as the pump and as the mixer local oscillator. A stable net gain of 15 dB in an instantaneous bandwidth (FWHM) of 3.4 GHz has been achieved. A system noise temperature of 220 plus or minus 5 K (DSB) was measured with a SUPARAMP contribution of only 20 plus or minus 10 K. Output saturation has been observed. This complicates the interpretation of noise-temperature measurements and may render them upper limits. Comparison is made with the results of an earlier 3-cm SUPARAMP.

  12. 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.

  13. Size Unbiased Representative Enzymatically Generated RNAi (SURER) Library and Application for RNAi Therapeutic Screens

    PubMed Central

    Li, Tiejun; Chen, Li; Sun, Yuncheng; Yuan, Jian; Graham, Michael; French, Peter

    2015-01-01

    RNA interference (RNAi) libraries screens have become widely used for small RNA (sRNA) therapeutic targets development. However, conventional enzymatically libraries, typically prepared using the type 2 restriction enzyme MmeI, produce sRNAs between 18 and 20 bp, much shorter than the usual lengths of 19–23 bp. Here we develop a size unbiased representative enzymatically generated RNAi (SURER) library, which employs type 3 restriction modification enzyme EcoP15I to produce sRNAs ranging from 19 to 23 bp using a group of rationally designed linkers, which can completely mimic the length of sRNAs naturally generated by Dicer enzyme in living cells, and the screening results of SURER libraries showed high recombination rate and knockdown efficiency. SURER library provides a useful tool for RNAi therapeutics screening in a fast and simple way. PMID:25493330

  14. Best Linear Unbiased Prediction of Individual Polygenic Susceptibility to Sporadic Vascular Dementia.

    PubMed

    Lee, Chaeyoung

    2016-05-31

    Genetic factors of sporadic vascular dementia have been quite limitedly understood. Many underlying polygenes are suspected to contribute to susceptibility to sporadic vascular dementia as a typical complex disease although they have not been identified from genome-wide association studies. This study suggests a stochastic prediction of individual polygenetic susceptibility to sporadic vascular dementia using best linear unbiased prediction in a mixed model framework. The prediction shows a relative degree of individual genetic susceptibility to the disease that reflects its integrative polygenetic factors across the genome. The estimate should take into account heritability and the prevalence of sporadic vascular dementia to cope with the disease. This offers a model for application of a genetic blueprint for a complex disease to personalized preventive medicine. PMID:27258425

  15. 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

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

    PubMed

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

    2015-10-15

    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

  17. Neosphincter surgery for fecal incontinence: a critical and unbiased review of the relevant literature.

    PubMed

    Belyaev, Orlin; Müller, Christophe; Uhl, Waldemar

    2006-01-01

    Up until about 15 years ago the only realistic option for end-stage fecal incontinence was the creation of a permanent stoma. There have since been several developments. Dynamic graciloplasty (DGP) and artificial bowel sphincter (ABS) are well-established surgical techniques, which offer the patient a chance for continence restoration and improved quality of life; however, they are unfortunately associated with high morbidity and low success rates. Several trials have been done in an attempt to clarify the advantages and disadvantages of these methods and define their place in the second-line treatment of severe, refractory fecal incontinence. This review presents a critical and unbiased overview of the current status of neosphincter surgery according to the available data in the world literature.

  18. Intrinsic Atomic Orbitals: An Unbiased Bridge between Quantum Theory and Chemical Concepts.

    PubMed

    Knizia, Gerald

    2013-11-12

    Modern quantum chemistry can make quantitative predictions on an immense array of chemical systems. However, the interpretation of those predictions is often complicated by the complex wave function expansions used. Here we show that an exceptionally simple algebraic construction allows for defining atomic core and valence orbitals, polarized by the molecular environment, which can exactly represent self-consistent field wave functions. This construction provides an unbiased and direct connection between quantum chemistry and empirical chemical concepts, and can be used, for example, to calculate the nature of bonding in molecules, in chemical terms, from first principles. In particular, we find consistency with electronegativities (χ), C 1s core-level shifts, resonance substituent parameters (σR), Lewis structures, and oxidation states of transition-metal complexes.

  19. 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

  20. 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

  1. Motor activity as an unbiased variable to assess anaphylaxis in allergic rats.

    PubMed

    Abril-Gil, Mar; Garcia-Just, Alba; Cambras, Trinitat; Pérez-Cano, Francisco J; Castellote, Cristina; Franch, Àngels; Castell, Margarida

    2015-10-01

    The release of mediators by mast cells triggers allergic symptoms involving various physiological systems and, in the most severe cases, the development of anaphylactic shock compromising mainly the nervous and cardiovascular systems. We aimed to establish variables to objectively study the anaphylactic response (AR) after an oral challenge in an allergy model. Brown Norway rats were immunized by intraperitoneal injection of ovalbumin with alum and toxin from Bordetella pertussis. Specific immunoglobulin (Ig) E antibodies were developed in immunized animals. Forty days after immunization, the rats were orally challenged with the allergen, and motor activity, body temperature and serum mast cell protease concentration were determined. The anaphylaxis induced a reduction in body temperature and a decrease in the number of animal movements, which was inversely correlated with serum mast cell protease release. In summary, motor activity is a reliable tool for assessing AR and also an unbiased method for screening new anti-allergic drugs.

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

    PubMed

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

    2015-10-15

    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.

  3. Quantitative estimation of climatic parameters from vegetation data in North America by the mutual climatic range technique

    USGS Publications Warehouse

    Anderson, Katherine H.; Bartlein, Patrick J.; Strickland, Laura E.; Pelltier, Richard T.; Thompson, Robert S.; Shafer, Sarah L.

    2012-01-01

    The mutual climatic range (MCR) technique is perhaps the most widely used method for estimating past climatic parameters from fossil assemblages, largely because it can be conducted on a simple list of the taxa present in an assemblage. When applied to plant macrofossil data, this unweighted approach (MCRun) will frequently identify a large range for a given climatic parameter where the species in an assemblage can theoretically live together. To narrow this range, we devised a new weighted approach (MCRwt) that employs information from the modern relations between climatic parameters and plant distributions to lessen the influence of the "tails" of the distributions of the climatic data associated with the taxa in an assemblage. To assess the performance of the MCR approaches, we applied them to a set of modern climatic data and plant distributions on a 25-km grid for North America, and compared observed and estimated climatic values for each grid point. In general, MCRwt was superior to MCRun in providing smaller anomalies, less bias, and better correlations between observed and estimated values. However, by the same measures, the results of Modern Analog Technique (MAT) approaches were superior to MCRwt. Although this might be reason to favor MAT approaches, they are based on assumptions that may not be valid for paleoclimatic reconstructions, including that: 1) the absence of a taxon from a fossil sample is meaningful, 2) plant associations were largely unaffected by past changes in either levels of atmospheric carbon dioxide or in the seasonal distributions of solar radiation, and 3) plant associations of the past are adequately represented on the modern landscape. To illustrate the application of these MCR and MAT approaches to paleoclimatic reconstructions, we applied them to a Pleistocene paleobotanical assemblage from the western United States. From our examinations of the estimates of modern and past climates from vegetation assemblages, we conclude that

  4. 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

  5. Water stress strengthens mutualism among ants, trees, and scale insects.

    PubMed

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

    2013-11-01

    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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. The macroecology of marine cleaning mutualisms.

    PubMed

    Floeter, Sergio R; Vázquez, Diego P; Grutter, Alexandra S

    2007-01-01

    1. Marine cleaning mutualisms generally involve small fish or shrimps removing ectoparasites and other material from cooperating 'client' fish. We evaluate the role of fish abundance, body size and behaviour as determinants of interactions with cleaning mutualists. 2. Data come from eight reef locations in Brazil, the Caribbean, the Mediterranean and Australia. 3. We conducted a meta-analysis of client-cleaner interactions involving 11 cleaner and 221 client species. 4. There was a strong, positive effect of client abundance on cleaning frequency, but only a weak, negative effect of client body size. These effects were modulated by client trophic group and social behaviour. 5. This study adds to a growing body of evidence suggesting a central role of species abundance in structuring species interactions.

  12. Quantum corrections to holographic mutual information

    NASA Astrophysics Data System (ADS)

    Agón, Cesar A.; Faulkner, Thomas

    2016-08-01

    We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy [1]. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal [2] this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.

  13. The fundamental role of competition in the ecology and evolution of mutualisms.

    PubMed

    Jones, Emily I; Bronstein, Judith L; Ferrière, Régis

    2012-05-01

    Mutualisms are interspecific interactions that yield reciprocal benefits. Here, by adopting a consumer-resource perspective, we show how considering competition is necessary in order to understand the evolutionary and ecological dynamics of mutualism. We first review the ways in which competition shapes the ecology of mutualisms, using a graphical framework based on resource flows rather than net effects to highlight the opportunities for competition. We then describe the known mechanisms of competition and show how it is a critical driver of the evolutionary dynamics, persistence, and diversification of mutualism. We argue that empirical and theoretical research on the ecology and evolution of mutualisms will jointly progress by addressing four key points: (i) the existence and shape of physiological trade-offs among cooperation, competition, and other life-history and functional traits; (ii) the capacity for individuals to express conditional responses to variation in their mutualistic and competitive environment; (iii) the existence of heritable variation for mutualistic and competitive traits and their potentially conditional expression; and (iv) the structure of the network of consumer-resource interactions in which individuals are embedded. PMID:22583047

  14. 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.

  15. Design of a compact optical see-through head-worn display with mutual occlusion capability

    NASA Astrophysics Data System (ADS)

    Cakmakci, Ozan; Ha, Yonggang; Rolland, Jannick

    2005-08-01

    We present the first-order design details and preliminary lens design and performance analysis of a compact optical system that can achieve mutual occlusions. Mutual occlusion is the ability of real objects to occlude virtual objects and virtual objects to occlude real objects. Mutual occlusion is a desirable attribute for a certain class of augmented reality applications where realistic overlays based on the depth cue is important. Compactness is achieved through the use of polarization optics. First order layout of the system is similar to that of a Keplerian telescope operating at finite conjugates. Additionally, we require the image to lie on the plane of the object with unit magnification. We show that the same lens can be used as the objective and the eyepiece. The system is capable of having very close to zero distortion.

  16. 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

  17. Fostering Practical Young Engineers through Mutual Exchange Internship Program between Japan and China

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Shigematsu, Toshinobu; Ono, Bunji; Watanabe, Tetsuya; Morishita, Koji; Inoue, Masahiro

    Sasebo National College of Technology started a mutual exchange internship program in 2005 in partnership with Xiamen University of Technology. The aim of this program is to educate and train young Japanese engineers who can apply their knowledge and skills fully to their work in the factories in China. This program also aims to educate and train young Chinese engineers who will acquire not only technological knowledge and skills but also an understanding of the organizational structure and cultural background of Japanese companies. By deepening mutual understanding between Japan and China through this program, young Japanese and Chinese engineers can work toward their common goal of economic prosperity in their respective countries, while building partnerships based on mutual trust and respect.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  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. 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.

  6. 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.

  7. Mutual Inductance in the Bird-Cage Resonator

    PubMed

    Tropp

    1997-05-01

    Formulas are derived to account for the effect of the mutual inductances, between all meshes, upon the electrical resonance spectra bird-cage resonators, and similar structures such as the TEM resonator of P. K. H. Roschmann (United States Patent 4,746,866) and J. T. Vaughan et al. (Magn. Reson. Med. 32, 206, 1994). The equations are parameterized in terms of isolated mesh frequencies and coupling coefficients, and ought therefore apply not only to simple magnetic couplings used in the derivation, but to electromagnetic couplings as well. A method for measuring the coupling coefficients-applicable to shielded as well as unshielded resonators-is described, based upon the splitting of frequencies in pairs of coupled resonators; and detailed comparisons are given between calculated and measured resonance spectra: for bird-cage resonators, with and without shields, and for the TEM resonator.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. Genomic best linear unbiased prediction method reflecting the degree of linkage disequilibrium.

    PubMed

    Nishio, M; Satoh, M

    2015-10-01

    The degree of linkage disequilibrium (LD) between markers differs depending on the location of the genome; this difference biases genetic evaluation by genomic best linear unbiased prediction (GBLUP). To correct this bias, we used three GBLUP methods reflecting the degree of LD (GBLUP-LD). In the three GBLUP-LD methods, genomic relationship matrices were conducted from single nucleotide polymorphism markers weighted according to local LD levels. The predictive abilities of GBLUP-LD were investigated by estimating variance components and assessing the accuracies of estimated breeding values using simulation data. When quantitative trait loci (QTL) were located at weak LD regions, the predictive abilities of the three GBLUP-LD methods were superior to those of GBLUP and Bayesian lasso except when the number of QTL was small. In particular, the superiority of GBLUP-LD increased with decreasing trait heritability. The rates of QTL at weak LD regions would increase when selection by GBLUP continues; this consequently decreases the predictive ability of GBLUP. Thus, the GBLUP-LD could be applicable for populations selected by GBLUP for a long time. However, if QTL were located at strong LD regions, the accuracies of three GBLUP-LD methods were lower than GBLUP and Bayesian lasso.

  15. 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

  16. P7C3 and an unbiased approach to drug discovery for neurodegenerative diseases

    PubMed Central

    McKnight, Steven L.; Ready, Joseph M.

    2014-01-01

    A novel neuroprotective small molecule was discovered using a target-agnostic in vivo screen in living mice. This aminopropyl carbazole, named P7C3, is orally bioavailable, crosses the blood–brain barrier, and is non-toxic at doses several fold higher than the efficacious dose. The potency and drug-like properties of P7C3 were optimized through a medicinal chemistry campaign, providing analogues for detailed examination. Improved versions, such as (−)-P7C3-S243 and P7C3-A20, displayed neuro-protective properties in rodent models of Parkinson’s disease, amyotrophic lateral sclerosis, traumatic brain injury and age-related cognitive decline. Derivatives appended with immobilizing moieties may reveal the protein targets of the P7C3 class of neuroprotective compounds. Our results indicate that unbiased, in vivo screens might provide starting points for the development of treatments for neurodegenerative diseases as well as tools to study the biology underlying these disorders. PMID:24514864

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 7 CFR 550.13 - Mutuality of interest.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 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...

  5. 7 CFR 550.13 - Mutuality of interest.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 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...

  6. 7 CFR 550.13 - Mutuality of interest.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Mutuality of interest. 550.13 Section 550.13 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ADMINISTRATIVE POLICY FOR NON-ASSISTANCE COOPERATIVE AGREEMENTS Formation of Agreements § 550.13 Mutuality of interest....

  7. 7 CFR 550.13 - Mutuality of interest.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 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...

  8. 47 CFR 22.131 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Procedures for mutually exclusive applications...) (according to the filing dates) as acceptable for filing. (4) Window filing group. A window filing group comprises mutually exclusive applications whose filing date is within an announced filing window....

  9. 47 CFR 22.131 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Procedures for mutually exclusive applications...) (according to the filing dates) as acceptable for filing. (4) Window filing group. A window filing group comprises mutually exclusive applications whose filing date is within an announced filing window....

  10. 47 CFR 22.131 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Procedures for mutually exclusive applications...) (according to the filing dates) as acceptable for filing. (4) Window filing group. A window filing group comprises mutually exclusive applications whose filing date is within an announced filing window....

  11. 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…

  12. GENERAL: Mutual Information and Relative Entropy of Sequential Effect Algebras

    NASA Astrophysics Data System (ADS)

    Wang, Jia-Mei; Wu, Jun-De; Cho, Minhyung

    2010-08-01

    In this paper, we introduce and investigate the mutual information and relative entropy on the sequential effect algebra, we also give a comparison of these mutual information and relative entropy with the classical ones by the venn diagrams. Finally, a nice example shows that the entropies of sequential effect algebra depend extremely on the order of its sequential product.

  13. 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...

  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. 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…

  16. 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...

  17. Genetic drift opposes mutualism during spatial population expansion.

    PubMed

    Müller, Melanie J I; Neugeboren, Beverly I; Nelson, David R; Murray, Andrew W

    2014-01-21

    Mutualistic interactions benefit both partners, promoting coexistence and genetic diversity. Spatial structure can promote cooperation, but spatial expansions may also make it hard for mutualistic partners to stay together, because genetic drift at the expansion front creates regions of low genetic and species diversity. To explore the antagonism between mutualism and genetic drift, we grew cross-feeding strains of the budding yeast Saccharomyces cerevisiae on agar surfaces as a model for mutualists undergoing spatial expansions. By supplying varying amounts of the exchanged nutrients, we tuned strength and symmetry of the mutualistic interaction. Strong mutualism suppresses genetic demixing during spatial expansions and thereby maintains diversity, but weak or asymmetric mutualism is overwhelmed by genetic drift even when mutualism is still beneficial, slowing growth and reducing diversity. Theoretical modeling using experimentally measured parameters predicts the size of demixed regions and how strong mutualism must be to survive a spatial expansion.

  18. 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.

  19. Calcium and ROS: A mutual interplay.

    PubMed

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-12-01

    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 Ca(2+) 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

  20. 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

  1. Calcium and ROS: A mutual interplay.

    PubMed

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-12-01

    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 Ca(2+) 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.

  2. Laser array having mutually coupled resonators

    SciTech Connect

    Sziklas, E.A.; Palma, G.E.

    1987-07-21

    A laser system is described having at least two independently pumped unstable laser resonators. Each has a feedback region in which optical radiation resonates, an output region. Output radiation exists from the feedback region and an output coupling means for coupling out a main beam from the region in which laser extracted radiation extracted from a first one of at least two unstable laser resonators is coupled unidirectionally into at least one other of the unstable laser resonators. The extracted radiation from the first unstable laser resonator influences at least one other unstable laser resonator. The improvement comprises a system in which each of the resonators is mutually and substantially symmetrically, bidirectionally coupled to at least one other unstable resonator, through extraction means for extracting at least one coupling portion of the output radiation. A coupling radiation power and transporting means transports at least one coupling portion of the output radiation that is mode-matched to an adjoint mode. At least one other unstable laser resonator into at least one corresponding output region of the other one of at least two unstable laser resonators produce a laser system having a scaled-up laser output.

  3. Economic game theory for mutualism and cooperation.

    PubMed

    Archetti, Marco; Scheuring, István; Hoffman, Moshe; Frederickson, Megan E; Pierce, Naomi E; Yu, Douglas W

    2011-12-01

    We review recent work at the interface of economic game theory and evolutionary biology that provides new insights into the evolution of partner choice, host sanctions, partner fidelity feedback and public goods. (1) The theory of games with asymmetrical information shows that the right incentives allow hosts to screen-out parasites and screen-in mutualists, explaining successful partner choice in the absence of signalling. Applications range from ant-plants to microbiomes. (2) Contract theory distinguishes two longstanding but weakly differentiated explanations of host response to defectors: host sanctions and partner fidelity feedback. Host traits that selectively punish misbehaving symbionts are parsimoniously interpreted as pre-adaptations. Yucca-moth and legume-rhizobia mutualisms are argued to be examples of partner fidelity feedback. (3) The theory of public goods shows that cooperation in multi-player interactions can evolve in the absence of assortment, in one-shot social dilemmas among non-kin. Applications include alarm calls in vertebrates and exoenzymes in microbes.

  4. Solvation of polymers as mutual association. I. General theory.

    PubMed

    Dudowicz, Jacek; Freed, Karl F; Douglas, Jack F

    2013-04-28

    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 χ(s) to the FH interaction parameter χ of polymer solutions, both with and without associative interactions. The entropic χ(s) 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 χ(s) for polymer solutions significantly exceeds χ(s) for binary polymer blends. Our calculations also reveal that χ(s) 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 χ(s) is simply assumed to be an adjustable constant based on experience with solutions of homopolymers in nonassociating solvents.

  5. 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

  6. Unbiased Review of Digital Diagnostic Images in Practice: Informatics Prototype and Pilot Study

    PubMed Central

    Fotenos, Anthony F.; Safdar, Nabile M.; Nagy, Paul G.; Mezrich, Reuben; Lewin, Jonathan S.

    2013-01-01

    care, despite integration of these records within production electronic workflow systems. Conclusion Information technology can facilitate the design of unbiased methods involving professional review of digital diagnostic images. PMID:23103185

  7. A practical methodology to measure unbiased gas chromatographic retention factor vs. temperature relationships.

    PubMed

    Peng, Baijie; Kuo, Mei-Yi; Yang, Panhia; Hewitt, Joshua T; Boswell, Paul G

    2014-12-29

    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 the 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 two-fold more error. Furthermore, temperature-programmed retention times calculated in five other laboratories 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.

  8. 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

  9. 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.

  10. 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

  11. Unbiased and non-supervised learning methods for disruption prediction at JET

    NASA Astrophysics Data System (ADS)

    Murari, A.; Vega, J.; Rattá, G. A.; Vagliasindi, G.; Johnson, M. F.; Hong, S. H.; JET-EFDA Contributors

    2009-05-01

    The importance of predicting the occurrence of disruptions is going to increase significantly in the next generation of tokamak devices. The expected energy content of ITER plasmas, for example, is such that disruptions could have a significant detrimental impact on various parts of the device, ranging from erosion of plasma facing components to structural damage. Early detection of disruptions is therefore needed with evermore increasing urgency. In this paper, the results of a series of methods to predict disruptions at JET are reported. The main objective of the investigation consists of trying to determine how early before a disruption it is possible to perform acceptable predictions on the basis of the raw data, keeping to a minimum the number of 'ad hoc' hypotheses. Therefore, the chosen learning techniques have the common characteristic of requiring a minimum number of assumptions. Classification and Regression Trees (CART) is a supervised but, on the other hand, a completely unbiased and nonlinear method, since it simply constructs the best classification tree by working directly on the input data. A series of unsupervised techniques, mainly K-means and hierarchical, have also been tested, to investigate to what extent they can autonomously distinguish between disruptive and non-disruptive groups of discharges. All these independent methods indicate that, in general, prediction with a success rate above 80% can be achieved not earlier than 180 ms before the disruption. The agreement between various completely independent methods increases the confidence in the results, which are also confirmed by a visual inspection of the data performed with pseudo Grand Tour algorithms.

  12. Unbiased Transcriptional Comparisons of Generalist and Specialist Herbivores Feeding on Progressively Defenseless Nicotiana attenuata Plants

    PubMed Central

    Govind, Geetha; Mittapalli, Omprakash; Griebel, Thasso; Allmann, Silke; Böcker, Sebastian; Baldwin, Ian Thomas

    2010-01-01

    Background Herbivore feeding elicits dramatic increases in defenses, most of which require jasmonate (JA) signaling, and against which specialist herbivores are thought to be better adapted than generalist herbivores. Unbiased transcriptional analyses of how neonate larvae cope with these induced plant defenses are lacking. Methodology/Principal Findings We created cDNA microarrays for Manduca sexta and Heliothis virescens separately, by spotting normalized midgut-specific cDNA libraries created from larvae that fed for 24 hours on MeJA-elicited wild-type (WT) Nicotiana attenuata plants. These microarrays were hybridized with labeled probes from neonates that fed for 24 hours on WT and isogenic plants progressively silenced in JA-mediated defenses (N: nicotine; N/PI: N and trypsin protease inhibitors; JA: all JA-mediated defenses). H. virescens neonates regulated 16 times more genes than did M. sexta neonates when they fed on plants silenced in JA-mediated defenses, and for both species, the greater the number of defenses silenced in the host plant (JA > N/PI > N), the greater were the number of transcripts regulated in the larvae. M. sexta larvae tended to down-regulate while H. virescens larvae up- and down-regulated transcripts from the same functional categories of genes. M. sexta larvae regulated transcripts in a diet-specific manner, while H. virescens larvae regulated a similar suite of transcripts across all diet types. Conclusions/Significance The observations are consistent with the expectation that specialists are better adapted than generalist herbivores to the defense responses elicited in their host plants by their feeding. While M. sexta larvae appear to be better adapted to N. attenuata's defenses, some of the elicited responses remain effective defenses against both herbivore species. The regulated genes provide novel insights into larval adaptations to N. attenuata's induced defenses, and represent potential targets for plant-mediated RNAi to

  13. 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.

  14. 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.

  15. The role of temperature variability in stabilizing the mountain pine beetle-fungus mutualism.

    PubMed

    Addison, A L; Powell, J A; Six, D L; Moore, M; Bentz, B J

    2013-10-21

    As global climate patterns continue to change and extreme weather events become increasingly common, it is likely that many ecological interactions will be affected. One such interaction is the multipartite symbiosis that exists between the mountain pine beetle and two species of fungi, Grosmannia clavigera and Ophiostoma montium. In this mutualism, the fungi provide nutrition to the beetle, while the fungi benefit by being dispersed to new host trees. Multi-partite mutualisms are predicted to be unstable due to strong direct competition among symbionts or natural selection for superior over inferior mutualists. However, this mutualism has remained stable over long periods of evolutionary time. In this paper, we developed a temperature-based model for the spread of fungi within a tree and connected it to an existing model for mountain pine beetle development. Using this integrated model for fungal growth, we explored the possibility that temperature variability is a stabilizing mechanism for the mountain pine beetle-fungi mutualism. Of the three types of temperature variability we tested: intra-year, inter-year and variability due to transitioning between different thermal habitats (thermal migration), we found that thermal migration was the most robust stabilizing mechanism. Additionally, we found that the MPB attack density or spacing between fungal lesions also had a significant effect on the stability of the system. High attack densities or close lesion spacings also tended to stabilize the system, regardless of temperature.

  16. 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...

  17. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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.

  5. 47 CFR 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 27.321 - Mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  7. 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.

  8. 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

  9. A novel unbiased proteomic approach to detect the reactivity of cerebrospinal fluid in neurological diseases.

    PubMed

    Menon, Krishnakumar N; Steer, David L; Short, Martin; Petratos, Steven; Smith, Ian; Bernard, Claude C A

    2011-06-01

    Neurodegenerative diseases, such as multiple sclerosis represent global health issues. Accordingly, there is an urgent need to understand the pathogenesis of this and other central nervous system disorders, so that more effective therapeutics can be developed. Cerebrospinal fluid is a potential source of important reporter molecules released from various cell types as a result of central nervous system pathology. Here, we report the development of an unbiased approach for the detection of reactive cerebrospinal fluid molecules and target brain proteins from patients with multiple sclerosis. To help identify molecules that may serve as clinical biomarkers for multiple sclerosis, we have biotinylated proteins present in the cerebrospinal fluid and tested their reactivity against brain homogenate as well as myelin and myelin-axolemmal complexes. Proteins were separated by two-dimensional gel electrophoresis, blotted onto membranes and probed separately with biotinylated unprocessed cerebrospinal fluid samples. Protein spots that reacted to two or more multiple sclerosis-cerebrospinal fluids were further analyzed by matrix assisted laser desorption ionization-time-of-flight time-of-flight mass spectrometry. In addition to previously reported proteins found in multiple sclerosis cerebrospinal fluid, such as αβ crystallin, enolase, and 14-3-3-protein, we have identified several additional molecules involved in mitochondrial and energy metabolism, myelin gene expression and/or cytoskeletal organization. These include aspartate aminotransferase, cyclophilin-A, quaking protein, collapsin response mediator protein-2, ubiquitin carboxy-terminal hydrolase L1, and cofilin. To further validate these findings, the cellular expression pattern of collapsin response mediator protein-2 and ubiquitin carboxy-terminal hydrolase L1 were investigated in human chronic-active MS lesions by immunohistochemistry. The observation that in multiple sclerosis lesions phosphorylated collapsin

  10. Age-related changes in rat cerebellar basket cells: a quantitative study using unbiased stereological methods

    PubMed Central

    HENRIQUE, RUI M. F.; ROCHA, EDUARDO; REIS, ALCINDA; MARCOS, RICARDO; OLIVEIRA, MARIA H.; SILVA, MARIA W.; MONTEIRO, ROGÉRIO A. F.

    2001-01-01

    Cortical cerebellar basket cells are stable postmitotic cells; hence, they are liable to endure age-related changes. Since the cerebellum is a vital organ for the postural control, equilibrium and motor coordination, we aimed to determine the quantitative morphological changes in those interneurons with the ageing process, using unbiased techniques. Material from the cerebellar cortex (Crus I and Crus II) was collected from female rats aged 2, 6, 9, 12, 15, 18, 21 and 24 mo (5 animals per each age group), fixed by intracardiac perfusion, and processed for transmission electron microscopy, using conventional techniques. Serial semithin sections were obtained (5 blocks from each rat), enabling the determination of the number-weighted mean nuclear volume (by the nucleator method). On ultrathin sections, 25 cell profiles from each animal were photographed. The volume density of the nucleus, ground substance, mitochondria, Golgi apparatus (Golgi) and dense bodies (DB), and the mean surface density of the rough endoplasmic reticulum (RER) were determined, by point counting, using a morphometric grid. The mean total volumes of the soma and organelles and the mean total surface area of the RER [s̄N (RER)] were then calculated. The results were analysed with 1-way ANOVA; posthoc pairwise comparisons of group means were performed using the Newman-Keuls test. The relation between age and each of the parameters was studied by regression analysis. Significant age-related changes were observed for the mean volumes of the soma, ground substance, Golgi, DB, and s̄N (RER). Positive linear trends were found for the mean volumes of the ground substance, Golgi, and DB; a negative linear trend was found for the s̄N (RER). These results indicate that rat cerebellar basket cells endure important age-related changes. The significant decrease in the s̄N (RER) may be responsible for a reduction in the rate of protein synthesis. Additionally, it may be implicated in a cascade of events

  11. 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.

  12. Contact prediction using mutual information and neural nets.

    PubMed

    Shackelford, George; Karplus, Kevin

    2007-01-01

    Prediction of protein structures continues to be a difficult problem, particularly when there are no solved structures for homologous proteins to use as templates. Local structure prediction (secondary structure and burial) is fairly reliable, but does not provide enough information to produce complete three-dimensional structures. Residue-residue contact prediction, though still not highly reliable, may provide a useful guide for assembling local structure prediction into full tertiary prediction. We develop a neural network which is applied to pairs of residue positions and outputs a probability of contact between the positions. One of the neural net inputs is a novel statistic for detecting correlated mutations: the statistical significance of the mutual information between the corresponding columns of a multiple sequence alignment. This statistic, combined with a second statistic based on the propensity of two amino acid types being in contact, results in a simple neural network that is a good predictor of contacts. Adding more features from amino-acid distributions and local structure predictions, the final neural network predicts contacts better than other submitted contact predictions at CASP7, including contact predictions derived from fragment-based tertiary models on free-modeling domains. It is still not known if contact predictions can improve tertiary models on free-modeling domains. Available at http://www.soe.ucsc.edu/research/compbio/SAM_T06/T06-query.html.

  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. Input impedance and mutual coupling of rectangular microstrip antennas

    NASA Technical Reports Server (NTRS)

    Pozar, D. M.

    1982-01-01

    A moment method solution to the problem of input impedance and mutual coupling of rectangular microstrip antenna elements is presented. The formulation uses the grounded dielectric slab Green's function to account rigorously for the presence of the substrate and surface waves. Both entire basis (EB) and piecewise sinusoidal (PWS) expansion modes are used, and their relative advantages are noted. Calculations of input impedance and mutual coupling are compared with measured data and other calculations.

  15. A measure for mutual refinements of image segmentations.

    PubMed

    Cardoso, Jaime S; Corte-Real, Luís

    2006-08-01

    In this paper, we recover a graph interpretation of the mutual partition distance, proposed recently by Cardoso and Corte-Real. We deduce some properties of this measure, and establish a correspondence with the partition distance introduced by Almudevar and Field and Gusfield, and independently by Guigues. We also present some different formulations for the computation of the mutual partition distance. Finally, a comparison is made with similar measures. PMID:16900689

  16. Benefit and cost curves for typical pollination mutualisms.

    PubMed

    Morris, William F; Vázquez, Diego P; Chacoff, Natacha P

    2010-05-01

    Mutualisms provide benefits to interacting species, but they also involve costs. If costs come to exceed benefits as population density or the frequency of encounters between species increases, the interaction will no longer be mutualistic. Thus curves that represent benefits and costs as functions of interaction frequency are important tools for predicting when a mutualism will tip over into antagonism. Currently, most of what we know about benefit and cost curves in pollination mutualisms comes from highly specialized pollinating seed-consumer mutualisms, such as the yucca moth-yucca interaction. There, benefits to female reproduction saturate as the number of visits to a flower increases (because the amount of pollen needed to fertilize all the flower's ovules is finite), but costs continue to increase (because pollinator offspring consume developing seeds), leading to a peak in seed production at an intermediate number of visits. But for most plant-pollinator mutualisms, costs to the plant are more subtle than consumption of seeds, and how such costs scale with interaction frequency remains largely unknown. Here, we present reasonable benefit and cost curves that are appropriate for typical pollinator-plant interactions, and we show how they can result in a wide diversity of relationships between net benefit (benefit minus cost) and interaction frequency. We then use maximum-likelihood methods to fit net-benefit curves to measures of female reproductive success for three typical pollination mutualisms from two continents, and for each system we chose the most parsimonious model using information-criterion statistics. We discuss the implications of the shape of the net-benefit curve for the ecology and evolution of plant-pollinator mutualisms, as well as the challenges that lie ahead for disentangling the underlying benefit and cost curves for typical pollination mutualisms.

  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. "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…

  19. Overcoming Addictions, a Web-Based Application, and SMART Recovery, an Online and In-Person Mutual Help Group for Problem Drinkers, Part 2: Six-Month Outcomes of a Randomized Controlled Trial and Qualitative Feedback From Participants

    PubMed Central

    Hester, Reid K; Lenberg, Kathryn L; Delaney, Harold D

    2016-01-01

    Background Despite empirical evidence supporting the use of Web-based interventions for problem drinking, much remains unknown about factors that influence their effectiveness. Objective We evaluated the performance of 2 resources for people who want to achieve and maintain abstinence: SMART Recovery (SR) and Overcoming Addictions (OA). OA is a Web application based on SR. We also examined participant and intervention-related factors hypothesized to impact clinical outcomes of Web-based interventions. Methods We recruited 189 heavy drinkers through SR’s website and in-person meetings throughout the United States. We began by randomly assigning participants to (1) SR meetings alone, (2) OA alone, and (3) OA and SR (OA+SR). Recruitment challenges compelled us to assign participants only to SR (n=86) or OA+SR (n=102). The experimental hypotheses were as follows: (1) Both groups will reduce their drinking and alcohol-related consequences at follow-up compared with their baseline levels, and (2) The OA+SR condition will reduce their drinking and alcohol or drug-related consequences more than the SR only condition. Additionally, we derived 3 groups empirically (SR, OA, and OA+SR) based on the participants’ actual use of each intervention and conducted analyses by comparing them. Primary outcome measures included percent days abstinent (PDA), mean drinks per drinking day (DDD), and alcohol or drug-related consequences. Postbaseline assessments were conducted by phone at 3 and 6 months. Secondary analyses explored whether clinical issues (eg, severity of alcohol problems, level of distress, readiness to change) or intervention-related factors (eg, Internet fluency, satisfaction with site) affected outcomes. Results Both intent-to-treat analyses and the actual-use analyses showed highly significant improvement from baseline to follow-ups for all 3 groups. Mean within-subject effect sizes were large (d>0.8) overall. There was no significant difference between groups in

  20. 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

  1. Phase-locked laser array through global antenna mutual coupling

    DOE PAGES

    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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Learning biological network using mutual information and conditional independence

    PubMed Central

    2010-01-01

    Background Biological networks offer us a new way to investigate the interactions among different components and address the biological system as a whole. In this paper, a reverse-phase protein microarray (RPPM) is used for the quantitative measurement of proteomic responses. Results To discover the signaling pathway responsive to RPPM, a new structure learning algorithm of Bayesian networks is developed based on mutual Information, conditional independence, and graph immorality. Trusted biology networks are thus predicted by the new approach. As an application example, we investigate signaling networks of ataxia telangiectasis mutation (ATM). The study was carried out at different time points under different dosages for cell lines with and without gene transfection. To validate the performance ofthe proposed algorithm, comparison experiments were also implemented using three well-known networks. From the experiment results, our approach produces more reliable networks with a relatively small number of wrong connection especially in mid-size networks. By using the proposed method, we predicted different networks for ATM under different doses of radiation treatment, and those networks were compared with results from eight different protein protein interaction (PPI) databases. Conclusions By using a new protein microarray technology in combination with a new computational framework, we demonstrate an application of the methodology to the study of biological networks of ATM cell lines under low dose ionization radiation. PMID:20438656

  7. 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.

  8. Equitability, mutual information, and the maximal information coefficient

    PubMed Central

    Kinney, Justin B.; Atwal, Gurinder S.

    2014-01-01

    How should one quantify the strength of association between two random variables without bias for relationships of a specific form? Despite its conceptual simplicity, this notion of statistical “equitability” has yet to receive a definitive mathematical formalization. Here we argue that equitability is properly formalized by a self-consistency condition closely related to Data Processing Inequality. Mutual information, a fundamental quantity in information theory, is shown to satisfy this equitability criterion. These findings are at odds with the recent work of Reshef et al. [Reshef DN, et al. (2011) Science 334(6062):1518–1524], which proposed an alternative definition of equitability and introduced a new statistic, the “maximal information coefficient” (MIC), said to satisfy equitability in contradistinction to mutual information. These conclusions, however, were supported only with limited simulation evidence, not with mathematical arguments. Upon revisiting these claims, we prove that the mathematical definition of equitability proposed by Reshef et al. cannot be satisfied by any (nontrivial) dependence measure. We also identify artifacts in the reported simulation evidence. When these artifacts are removed, estimates of mutual information are found to be more equitable than estimates of MIC. Mutual information is also observed to have consistently higher statistical power than MIC. We conclude that estimating mutual information provides a natural (and often practical) way to equitably quantify statistical associations in large datasets. PMID:24550517

  9. Equitability, mutual information, and the maximal information coefficient.

    PubMed

    Kinney, Justin B; Atwal, Gurinder S

    2014-03-01

    How should one quantify the strength of association between two random variables without bias for relationships of a specific form? Despite its conceptual simplicity, this notion of statistical "equitability" has yet to receive a definitive mathematical formalization. Here we argue that equitability is properly formalized by a self-consistency condition closely related to Data Processing Inequality. Mutual information, a fundamental quantity in information theory, is shown to satisfy this equitability criterion. These findings are at odds with the recent work of Reshef et al. [Reshef DN, et al. (2011) Science 334(6062):1518-1524], which proposed an alternative definition of equitability and introduced a new statistic, the "maximal information coefficient" (MIC), said to satisfy equitability in contradistinction to mutual information. These conclusions, however, were supported only with limited simulation evidence, not with mathematical arguments. Upon revisiting these claims, we prove that the mathematical definition of equitability proposed by Reshef et al. cannot be satisfied by any (nontrivial) dependence measure. We also identify artifacts in the reported simulation evidence. When these artifacts are removed, estimates of mutual information are found to be more equitable than estimates of MIC. Mutual information is also observed to have consistently higher statistical power than MIC. We conclude that estimating mutual information provides a natural (and often practical) way to equitably quantify statistical associations in large datasets.

  10. Equitability, mutual information, and the maximal information coefficient.

    PubMed

    Kinney, Justin B; Atwal, Gurinder S

    2014-03-01

    How should one quantify the strength of association between two random variables without bias for relationships of a specific form? Despite its conceptual simplicity, this notion of statistical "equitability" has yet to receive a definitive mathematical formalization. Here we argue that equitability is properly formalized by a self-consistency condition closely related to Data Processing Inequality. Mutual information, a fundamental quantity in information theory, is shown to satisfy this equitability criterion. These findings are at odds with the recent work of Reshef et al. [Reshef DN, et al. (2011) Science 334(6062):1518-1524], which proposed an alternative definition of equitability and introduced a new statistic, the "maximal information coefficient" (MIC), said to satisfy equitability in contradistinction to mutual information. These conclusions, however, were supported only with limited simulation evidence, not with mathematical arguments. Upon revisiting these claims, we prove that the mathematical definition of equitability proposed by Reshef et al. cannot be satisfied by any (nontrivial) dependence measure. We also identify artifacts in the reported simulation evidence. When these artifacts are removed, estimates of mutual information are found to be more equitable than estimates of MIC. Mutual information is also observed to have consistently higher statistical power than MIC. We conclude that estimating mutual information provides a natural (and often practical) way to equitably quantify statistical associations in large datasets. PMID:24550517

  11. 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

  12. 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

  13. 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.

  14. 26 CFR 1.822-5 - Mutual insurance company taxable income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TAX (CONTINUED) INCOME TAXES Mutual Insurance Companies (other Than Life and Certain Marine Insurance... Premium Deposits) § 1.822-5 Mutual insurance company taxable income. (a) Mutual insurance company taxable... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Mutual insurance company taxable income....

  15. 77 FR 73700 - Mutual of America Life Insurance Company, et al;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... COMMISSION Mutual of America Life Insurance Company, et al; Notice of Application December 5, 2012. AGENCY... the Act from Section 17(a) of the Act. APPLICANTS: Mutual of America Life Insurance Company (``Mutual... America Life Insurance Company, the ``Insurance Companies''), Mutual of America Separate Account No....

  16. 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.

  17. [Method of multi-resolution 3D image registration by mutual information].

    PubMed

    Ren, Haiping; Wu, Wenkai; Yang, Hu; Chen, Shengzu

    2002-12-01

    Maximization of mutual information is a powerful criterion for 3D medical image registration, allowing robust and fully accurate automated rigid registration of multi-modal images in a various applications. In this paper, a method based on normalized mutual information for 3D image registration was presented on the images of CT, MR and PET. Powell's direction set method and Brent's one-dimensional optimization algorithm were used as optimization strategy. A multi-resolution approach is applied to speedup the matching process. For PET images, pre-procession of segmentation was performed to reduce the background artefacts. According to the evaluation by the Vanderbilt University, Sub-voxel accuracy in multi-modality registration had been achieved with this algorithm. PMID:12561358

  18. 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

  19. A class of warm Jupiters with mutually inclined, apsidally misaligned close friends.

    PubMed

    Dawson, Rebekah I; Chiang, Eugene

    2014-10-10

    The orbits of giant extrasolar planets often have surprisingly small semimajor axes, large eccentricities, or severe misalignments between their orbit normals and their host stars' spin axes. In some formation scenarios invoking Kozai-Lidov oscillations, an external planetary companion drives a planet onto an orbit having these properties. The mutual inclinations for Kozai-Lidov oscillations can be large and have not been confirmed observationally. Here we present evidence that observed eccentric warm Jupiters with eccentric giant companions have mutual inclinations that oscillate between 35° and 65°. Our inference is based on the pairs' observed apsidal separations, which cluster near 90°. The near-orthogonality of periapse directions is effected by the outer companion's quadrupolar and octupolar potentials. These systems may be undergoing a stalled version of tidal migration that produces warm Jupiters over hot Jupiters, and they provide evidence for a population of multiplanet systems that are not flat and have been sculpted by Kozai-Lidov oscillations.

  20. 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.

  1. Balanced-PCR amplification allows unbiased identification of genomic copy changes in minute cell and tissue samples.

    PubMed

    Wang, Gang; Brennan, Cameron; Rook, Martha; Wolfe, Jia Liu; Leo, Christopher; Chin, Lynda; Pan, Hongjie; Liu, Wei-Hua; Price, Brendan; Makrigiorgos, G Mike

    2004-05-21

    Analysis of genomic DNA derived from cells and fresh or fixed tissues often requires whole genome amplification prior to microarray screening. Technical hurdles to this process are the introduction of amplification bias and/or the inhibitory effects of formalin fixation on DNA amplification. Here we demonstrate a balanced-PCR procedure that allows unbiased amplification of genomic DNA from fresh or modestly degraded paraffin-embedded DNA samples. Following digestion and ligation of a target and a control genome with distinct linkers, the two are mixed and amplified in a single PCR, thereby avoiding biases associated with PCR saturation and impurities. We demonstrate genome-wide retention of allelic differences following balanced-PCR amplification of DNA from breast cancer and normal human cells and genomic profiling by array-CGH (cDNA arrays, 100 kb resolution) and by real-time PCR (single gene resolution). Comparison of balanced-PCR with multiple displacement amplification (MDA) demonstrates equivalent performance between the two when intact genomic DNA is used. When DNA from paraffin-embedded samples is used, balanced PCR overcomes problems associated with modest DNA degradation and produces unbiased amplification whereas MDA does not. Balanced-PCR allows amplification and recovery of modestly degraded genomic DNA for subsequent retrospective analysis of human tumors with known outcomes.

  2. Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking.

    PubMed

    Houel, Julien; Doan, Quang T; Cajgfinger, Thomas; Ledoux, Gilles; Amans, David; Aubret, Antoine; Dominjon, Agnès; Ferriol, Sylvain; Barbier, Rémi; Nasilowski, Michel; Lhuillier, Emmanuel; Dubertret, Benoît; Dujardin, Christophe; Kulzer, Florian

    2015-01-27

    We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nanoemitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the microsecond time scale.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Mutual exclusivity in autism spectrum disorders: testing the pragmatic hypothesis.

    PubMed

    de Marchena, Ashley; Eigsti, Inge-Marie; Worek, Amanda; Ono, Kim Emiko; Snedeker, Jesse

    2011-04-01

    While there is ample evidence that children treat words as mutually exclusive, the cognitive basis of this bias is widely debated. We focus on the distinction between pragmatic and lexical constraints accounts. High-functioning children with autism spectrum disorders (ASD) offer a unique perspective on this debate, as they acquire substantial vocabularies despite impoverished social-pragmatic skills. We tested children and adolescents with ASD in a paradigm examining mutual exclusivity for words and facts. Words were interpreted contrastively more often than facts. Word performance was associated with vocabulary size; fact performance was associated with social-communication skills. Thus mutual exclusivity does not appear to be driven by pragmatics, suggesting that it is either a lexical constraint or a reflection of domain-general learning processes.

  8. 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

  9. Life-history differences among coral reef sponges promote mutualism or exploitation of mutualism by influencing partner fidelity feedback.

    PubMed

    Wulff, Janie L

    2008-05-01

    Mutualism can be favored over exploitation of mutualism when interests of potential heterospecific partners are aligned so that individual organisms are beneficial to each others' continued growth, survival, and reproduction, that is, when exploitation of a particular partner individual is costly. A coral reef sponge system is particularly amenable to field experiments probing how costs of exploitation can be influenced by life-history characteristics. Pairwise associations among three of the sponge species are mutually beneficial. A fourth species, Desmapsamma anchorata, exploits these mutualisms. Desmapsamma also differs from the other species by growing faster, fragmenting more readily, and suffering higher mortality rates. Evaluating costs and benefits of association in the context of the complex life histories of these asexually fragmenting sponges shows costs of exploitation to be high for the mutualistic species but very low for this essentially weedy species. Although it benefits from association more than the mutualist species, by relying on their superior tensile strength and extensibility to reduce damage by physical disturbance, exploitation is favored because each individual host is of only ephemeral use. These sponges illustrate how life-history differences can influence the duration of association between individuals and, thus, the role of partner fidelity in promoting mutualism. PMID:18419569

  10. 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.

  11. 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.

  12. 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.

  13. Mutual Event of Transneptunian Binary (79360) Sila-Nunam

    NASA Astrophysics Data System (ADS)

    Verbiscer, Anne; Grundy, Will; Benecchi, Susan; Rabinowitz, David

    2013-02-01

    The transneptunian binary (79360) Sila-Nunam (provisionally designated 1997 CS29) is currently undergoing mutual events in which the two nearly-equal brightness components alternate in eclipsing and occulting each other as seen from Earth (Grundy et al. 2012, Verbiscer et al. 2012a). The low eccentricity of the orbit, determined from Hubble Space Telescope observations of the resolved components (Grundy et al. 2012), and the coincidence of the system's photometric lightcurve and orbital period are consistent with a system that is tidally locked and synchronized, like that of Pluto-Charon. Mutual events provide a rich opportunity to learn about size, shape, color, and albedo patterns on the system components. Mutual events of Pluto-Charon observed between 1985-1990 provided the first characterization of their albedo distributions. The duration of the mutual event season depends on the size and separation of the system components. Using sizes determined from thermal observations, the mutual event season for Sila-Nunam should last about a decade; however, the deepest, most central (and thus most informative) events are predicted to be observable in the 2013 apparition, with progressively shallower events observable thereafter for the next 4-5 years. Gemini-North is ideally located to observe a complete mutual event of Sila-Nunam which begins at 5:59 UT on 14 February 2013 and ends at 14:17. Since Sila-Nunam will be near opposition, the target is visible to GMOS for the entire night. This event is a rare opportunity to determine the size, density, and albedo/color patterns on a primitive body which has likely been unaltered since the time of Solar System formation.

  14. 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

  15. An unbiased infrared H2 search for embedded flows from young stars in Orion A

    NASA Astrophysics Data System (ADS)

    Stanke, Thomas

    2000-07-01

    The presence of outflows, often in the form of well-collimated jets, is a phenomenon commonly associated with the birth of young stars. Emission from shock-excited molecular hydrogen at near-infrared wavelengths is one of the signposts of the presence of such an outflow, and generally can be observed even if the flow is obscured at optical wavelengths. In this thesis, I present the results of an unbiased, sensitive, wide-field search for flows from protostellar objects in the v=1-0 S(1) line at a wavelength of 2.12 μm, covering a 1 square degree area of the Orion A giant molecular cloud. Further data covering a wide wavelength range are used to search for the driving sources of the flows. The aim of this work is to obtain a sample of outflows which is free from biases as far as possible, to derive the typical properties of the outflows, to search for evolutionary trends, and to examine the impact of outflows on the ambient cloud. The first result from this survey is that outflows are indeed common in star forming regions: more than 70 candidate jets are identified. Most of them have a fairly ill-defined morphology rather than a regular or symmetric structure, which is interpreted to be due to the turbulent, clumpy ambient medium into which the jets are propagating. The jets are randomly oriented. In particular, no alignment of the jets with the large scale ambient magnetic field is found, suggesting that the spin and symmetry axis in a protostellar object is determined by random, turbulent motions in the cloud. Candidate driving sources are identified for 49 jets, and their evolutionary stage and bolometric luminosity is estimated. The jet lengths and H2 luminosities evolve as a function of the age of the driving source: the jets grow quickly from zero length to a size of a few parsec and then slowly shorten again. The jets are very luminous early on and fade during the protostellar evolution. The evolution in length and H2 luminosity is attributed to an early

  16. Cross Correlation versus Normalized Mutual Information on Image Registration

    NASA Technical Reports Server (NTRS)

    Tan, Bin; Tilton, James C.; Lin, Guoqing

    2016-01-01

    This is the first study to quantitatively assess and compare cross correlation and normalized mutual information methods used to register images in subpixel scale. The study shows that the normalized mutual information method is less sensitive to unaligned edges due to the spectral response differences than is cross correlation. This characteristic makes the normalized image resolution a better candidate for band to band registration. Improved band-to-band registration in the data from satellite-borne instruments will result in improved retrievals of key science measurements such as cloud properties, vegetation, snow and fire.

  17. 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

  18. Species independence of mutual information in coding and noncoding DNA

    NASA Astrophysics Data System (ADS)

    Grosse, Ivo; Herzel, Hanspeter; Buldyrev, Sergey V.; Stanley, H. Eugene

    2000-05-01

    We explore if there exist universal statistical patterns that are different in coding and noncoding DNA and can be found in all living organisms, regardless of their phylogenetic origin. We find that (i) the mutual information function I has a significantly different functional form in coding and noncoding DNA. We further find that (ii) the probability distributions of the average mutual information I¯ are significantly different in coding and noncoding DNA, while (iii) they are almost the same for organisms of all taxonomic classes. Surprisingly, we find that I¯ is capable of predicting coding regions as accurately as organism-specific coding measures.

  19. Learning and Development: Mutual Bases in a Dialectical Perspective.

    ERIC Educational Resources Information Center

    Fitzgerald, J. M.

    1980-01-01

    Argues that learning is an invariant process best understood from a dialectical perspective which demands that learning be viewed as an interaction between the organism and the environment. This view is contrasted with traditional operant approaches and with a Piagetian approach. (Author/DB)

  20. 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…

  1. A complex network model for seismicity based on mutual information

    NASA Astrophysics Data System (ADS)

    Jiménez, Abigail

    2013-05-01

    Seismicity is the product of the interaction between the different parts of the lithosphere. Here, we model each part of the Earth as a cell that is constantly communicating its state to its environment. As a neuron is stimulated and produces an output, the different parts of the lithosphere are constantly stimulated by both other cells and the ductile part of the lithosphere, and produce an output in the form of a stress transfer or an earthquake. This output depends on the properties of each part of the Earth’s crust and the magnitude of the inputs. In this study, we propose an approach to the quantification of this communication, with the aid of the Information Theory, and model seismicity as a Complex Network. We have used data from California, and this new approach gives a better understanding of the processes involved in the formation of seismic patterns in that region.

  2. Mutual information criterion for feature selection with application to classification of breast microcalcifications

    NASA Astrophysics Data System (ADS)

    Diamant, Idit; Shalhon, Moran; Goldberger, Jacob; Greenspan, Hayit

    2016-03-01

    Classification of clustered breast microcalcifications into benign and malignant categories is an extremely challenging task for computerized algorithms and expert radiologists alike. In this paper we present a novel method for feature selection based on mutual information (MI) criterion for automatic classification of microcalcifications. We explored the MI based feature selection for various texture features. The proposed method was evaluated on a standardized digital database for screening mammography (DDSM). Experimental results demonstrate the effectiveness and the advantage of using the MI-based feature selection to obtain the most relevant features for the task and thus to provide for improved performance as compared to using all features.

  3. Employing mutually injection-locked FP LDs scheme over full-duplex radio-on-fiber transport systems

    NASA Astrophysics Data System (ADS)

    Lin, Wen-I.; Lu, Hai-Han; Tzeng, Shah-Jye; Chang, Kuo-Hsiang; Hsiao, Yu-Chao

    2009-02-01

    A full-duplex radio-on-fiber (ROF) transport system based on mutually injection-locked Fabry-Perot laser diodes (FP LDs) as light source is proposed and demonstrated. Transmission performances over a 40-km standard single-mode fiber (SMF) for full-duplex transmission were investigated. Good performance of bit error rate (BER) was achieved in our proposed systems. We directly modulate the FP LDs in mutually injection-locked scheme instead of using expensive external modulator and sophisticated optical carrier suppression technique; it reveals an outstanding alternative with advantages in simplicity and cost.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Comparative evaluation of multiresolution optimization strategies for multimodality image registration by maximization of mutual information.

    PubMed

    Maes, F; Vandermeulen, D; Suetens, P

    1999-12-01

    Maximization of mutual information of voxel intensities has been demonstrated to be a very powerful criterion for three-dimensional medical image registration, allowing robust and accurate fully automated affine registration of multimodal images in a variety of applications, without the need for segmentation or other preprocessing of the images. In this paper, we investigate the performance of various optimization methods and multiresolution strategies for maximization of mutual information, aiming at increasing registration speed when matching large high-resolution images. We show that mutual information is a continuous function of the affine registration parameters when appropriate interpolation is used and we derive analytic expressions of its derivatives that allow numerically exact evaluation of its gradient. Various multiresolution gradient- and non-gradient-based optimization strategies, such as Powell, simplex, steepest-descent, conjugate-gradient, quasi-Newton and Levenberg-Marquardt methods, are evaluated for registration of computed tomography (CT) and magnetic resonance images of the brain. Speed-ups of a factor of 3 on average compared to Powell's method at full resolution are achieved with similar precision and without a loss of robustness with the simplex, conjugate-gradient and Levenberg-Marquardt method using a two-level multiresolution scheme. Large data sets such as 256(2) x 128 MR and 512(2) x 48 CT images can be registered with subvoxel precision in <5 min CPU time on current workstations. PMID:10709702

  12. 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.

  13. 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.

  14. Effects of mutual shading on the regulation of photosynthesis in field-grown sorghum.

    PubMed

    Li, Tao; Liu, Li-Na; Jiang, Chuang-Dao; Liu, Yu-Jun; Shi, Lei

    2014-08-01

    In the field, close planting inevitably causes mutual shading and depression of leaf photosynthesis. To clarify the regulative mechanisms of photosynthesis under these conditions, the effects of planting density on leaf structure, gas exchange and proteomics were carefully studied in field-grown sorghum. In the absence of mineral deficiency, (1) close planting induced a significant decrease in light intensity within populations, which further resulted in much lower stomatal density and other anatomical characteristics associated with shaded leaves; (2) sorghum grown at high planting density had a lower net photosynthetic rate and stomatal conductance than those grown at low planting density; (3) approximately 62 protein spots changed their expression levels under the high planting density conditions, and 22 proteins associated with photosynthesis were identified by mass spectrometry. Further analysis revealed the depression of photosynthesis caused by mutual shading involves the regulation of leaf structure, absorption and transportation of CO2, photosynthetic electron transport, production of assimilatory power, and levels of enzymes related to the Calvin cycle. Additionally, heat shock protein and oxygen-evolving enhancer protein play important roles in photoprotection in field-grown sorghum. A model for the regulation of photosynthesis under mutual shading was suggested based on our results.

  15. 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.

  16. 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

  17. Comparison of time series using entropy and mutual correlation

    NASA Astrophysics Data System (ADS)

    Madonna, Fabio; Rosoldi, Marco

    2015-04-01

    The potential for redundant time series to reduce uncertainty in atmospheric variables has not been investigated comprehensively for climate observations. Moreover, comparison among time series of in situ and ground based remote sensing measurements have been performed using several methods, but quite often relying on linear models. In this work, the concepts of entropy (H) and mutual correlation (MC), defined in the frame of the information theory, are applied to the study of essential climate variables with the aim of characterizing the uncertainty of a time series and the redundancy of collocated measurements provided by different surface-based techniques. In particular, integrated water vapor (IWV) and water vapour mixing ratio times series obtained at five highly instrumented GRUAN (GCOS, Global Climate Observing System, Reference Upper-Air Network) stations with several sensors (e.g radiosondes, GPS, microwave and infrared radiometers, Raman lidar), in the period from 2010-2012, are analyzed in terms of H and MC. The comparison between the probability density functions of the time series shows that caution in using linear assumptions is needed and the use of statistics, like entropy, that are robust to outliers, is recommended to investigate measurements time series. Results reveals that the random uncertainties on the IWV measured with radiosondes, global positioning system, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8 % over the considered time period. Comparisons of the time series of IWV content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy with the IWV time series measured by radiosondes and therefore the highest potential to reduce the random uncertainty of the radiosondes time series. Moreover, the random uncertainty of a time series from one instrument can be reduced by 60% by constraining the measurements with those from

  18. 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.

  19. Anomalous, extreme weather disrupts obligate seed dispersal mutualism: snow in a subtropical forest ecosystem.

    PubMed

    Zhou, Youbing; Newman, Chris; Chen, Jin; Xie, Zongqiang; Macdonald, David W

    2013-09-01

    Ongoing global climate change is predicted to increase the frequency and magnitude of extreme weather events, impacting population dynamics and community structure. There is, however, a critical lack of case studies considering how climatic perturbations affect biotic interactions. Here, we document how an obligate seed dispersal mutualism was disrupted by a temporally anomalous and meteorologically extreme interlude of unseasonably frigid weather, with accompanying snowstorms, in subtropical China, during January-February 2008. Based on the analysis of 5892 fecal samples (representing six mammalian seed dispersers), this event caused a substantial disruption to the relative seed dispersal function for the raisin tree Hovenia dulcis from prestorm 6.29 (2006) and 11.47 (2007), down to 0.35 during the storm (2008). Crucially, this was due to impacts on mammalian seed dispersers and not due to a paucity of fruit, where 4.63 fruit per branch were available in January 2008, vs. 3.73 in 2006 and 3.58 in 2007. An induced dietary shift occurred among omnivorous carnivores during this event, from the consumption fruit to small mammals and birds, reducing their role in seed dispersal substantially. Induced range shift extinguished the functionality of herbivorous mammals completely, however, seed dispersal function was compensated in part by three omnivorous carnivores during poststorm years, and thus while the mutualism remained intact it was enacted by a narrower assemblage of species, rendering the system more vulnerable to extrinsic perturbations. The storm's extended effects also had anthropogenic corollaries - migrating ungulates becoming exposed to heightened levels of illegal hunting - causing long-term modification to the seed dispersal community and mutualism dynamics. Furthermore, degraded forests proved especially vulnerable to the storm's effects. Considering increasing climate variability and anthropogenic disturbance, the impacts of such massive, aberrant

  20. Negotiation of mutualism: rhizobia and legumes

    PubMed Central

    Akçay, Erol; Roughgarden, Joan

    2006-01-01

    The evolution and persistence of biological cooperation have been an important puzzle in evolutionary theory. Here, we suggest a new approach based on bargaining theory to tackle the question. We present a mechanistic model for negotiation of benefits between a nitrogen-fixing nodule and a legume plant. To that end, we first derive growth rates for the nodule and plant from metabolic models of each as a function of material fluxes between them. We use these growth rates as pay-off functions in the negotiation process, which is analogous to collective bargaining between a firm and a workers' union. Our model predicts that negotiations lead to the Nash bargaining solution, maximizing the product of players' pay-offs. This work introduces elements of cooperative game theory into the field of mutualistic interactions. In the discussion of the paper, we argue for the benefits of such an approach in studying the question of biological cooperation. PMID:17015340

  1. 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

  2. Mutualism breakdown by amplification of Wolbachia genes.

    PubMed

    Chrostek, Ewa; Teixeira, Luis

    2015-02-01

    Most insect species are associated with vertically transmitted endosymbionts. Because of the mode of transmission, the fitness of these symbionts is dependent on the fitness of the hosts. Therefore, these endosymbionts need to control their proliferation in order to minimize their cost for the host. The genetic bases and mechanisms of this regulation remain largely undetermined. The maternally inherited bacteria of the genus Wolbachia are the most common endosymbionts of insects, providing some of them with fitness benefits. In Drosophila melanogaster, Wolbachia wMelPop is a unique virulent variant that proliferates massively in the hosts and shortens their lifespan. The genetic bases of wMelPop virulence are unknown, and their identification would allow a better understanding of how Wolbachia levels are regulated. Here we show that amplification of a region containing eight Wolbachia genes, called Octomom, is responsible for wMelPop virulence. Using Drosophila lines selected for carrying Wolbachia with different Octomom copy numbers, we demonstrate that the number of Octomom copies determines Wolbachia titers and the strength of the lethal phenotype. Octomom amplification is unstable, and reversion of copy number to one reverts all the phenotypes. Our results provide a link between genotype and phenotype in Wolbachia and identify a genomic region regulating Wolbachia proliferation. We also prove that these bacteria can evolve rapidly. Rapid evolution by changes in gene copy number may be common in endosymbionts with a high number of mobile elements and other repeated regions. Understanding wMelPop pathogenicity and variability also allows researchers to better control and predict the outcome of releasing mosquitoes transinfected with this variant to block human vector-borne diseases. Our results show that transition from a mutualist to a pathogen may occur because of a single genomic change in the endosymbiont. This implies that there must be constant selection on

  3. Evolution of the Fusarium–Euwallacea ambrosia beetle mutualism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Euwallacea – Fusarium mutualistic symbiosis represents one of the independent evolutionary origins of fungus-farming. Diversification time estimates place the evolutionary origin of this mutualism in the early Miocene approximately 21 million years ago. Fusarium is best known as one of the most ...

  4. Flexible Use of Mutual Exclusivity in Word Learning

    ERIC Educational Resources Information Center

    Kalashnikova, Marina; Mattock, Karen; Monaghan, Padraic

    2016-01-01

    From an early age, children apply the mutual exclusivity (ME) assumption, demonstrating preference for one-to-one mappings between words and their referents. However, for the acquisition of referentially overlapping terms, ME use must be suspended. We test whether contextual cues to intended meaning, in the form of presence of a speaker, may be…

  5. A Mutual Support Group for Young Problem Gamblers

    ERIC Educational Resources Information Center

    Binde, Per

    2012-01-01

    A Swedish mutual support group for young problem gamblers is described and discussed. During the study period, 116 weekly meetings occurred, usually involving six to ten participants; in total, 69 problem gamblers (66 male and three female), aged 17-25, and 23 partners and friends attended the meetings. Half the gamblers had problems with Internet…

  6. 47 CFR 22.131 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) (according to the filing dates) as acceptable for filing. (4) Window filing group. A window filing group comprises mutually exclusive applications whose filing date is within an announced filing window. An announced filing window is a period of time between and including two specific dates, which are the...

  7. 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.

  8. Quantum mutual information and the one-time pad

    SciTech Connect

    Schumacher, Benjamin; Westmoreland, Michael D.

    2006-10-15

    Alice and Bob share a correlated composite quantum system AB. If AB is used as the key for a one-time pad cryptographic system, we show that the maximum amount of information that Alice can send securely to Bob is the quantum mutual information of AB.

  9. 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

  10. 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"…

  11. 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…

  12. 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.

  13. 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.

  14. The blind leading the blind: Mutual refinement of approximate theories

    NASA Technical Reports Server (NTRS)

    Kedar, Smadar T.; Bresina, John L.; Dent, C. Lisa

    1991-01-01

    The mutual refinement theory, a method for refining world models in a reactive system, is described. The method detects failures, explains their causes, and repairs the approximate models which cause the failures. The approach focuses on using one approximate model to refine another.

  15. Mutual Support Groups for Long-Term Recipients of TANF

    ERIC Educational Resources Information Center

    Anderson-Butcher, Dawn; Khairallah, Angela Oliver; Race-Bigelow, Janis

    2004-01-01

    This study examined the effect of involvement in mutual support groups on long-term recipients of Temporary Assistance for Needy Families (TANF) and other vulnerable individuals. From qualitative interviews with nine group members, the study identified key themes, benefits, and barriers related to involvement in the groups. Content analysis of the…

  16. Sex Education, State Policy and the Principle of Mutual Consent

    ERIC Educational Resources Information Center

    Steutel, Jan; Spiecker, Ben

    2004-01-01

    Constitutive of the prevalent sexual morality in most Western European countries is the liberal principle of mutual consent (PMC). This sociological fact may give rise to the ethical question as to whether or not the state has the right to make sure that its citizens will observe PMC, among other ways by prescribing some form of sex education…

  17. 47 CFR 24.431 - Mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... exclusive if their conflicts are such that the grant of one application would effectively preclude by reason... result in a material impairment to service rendered to the public despite full cooperation in good faith... conflict. (b) Mutually exclusive applications filed on Form 175 for the initial provision of narrowband...

  18. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... savings account or a deposit and it is not insured by the United States or any agency or fund of the United States”; and (ii) Shall clearly state that the certificate is subject to the requirements of § 563... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Mutual capital certificates. 563.74 Section...

  19. 12 CFR 563.74 - Mutual capital certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... savings account or a deposit and it is not insured by the United States or any agency or fund of the United States”; and (ii) Shall clearly state that the certificate is subject to the requirements of § 563... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Mutual capital certificates. 563.74 Section...

  20. 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…

  1. 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.

  2. 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

  3. 12 CFR 163.74 - Mutual capital certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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...

  4. 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... parity with another class of mutual capital certificates; or (F) Action is sought which would...

  5. 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...

  6. 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…

  7. 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... part of its continuing effort to reduce paperwork and respondent burden, invites the general public and other Federal agencies to comment on proposed and continuing information collections, as required by...

  8. 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... request (ICR) described below has been submitted to the Office of Management and Budget (OMB) for review....reginfo.gov/public/do/PRAMain . ADDRESSES: Send comments, referring to the collection by title of...

  9. Chinese and American Women: Issues of Mutual Concern. Wingspread Brief.

    ERIC Educational Resources Information Center

    Johnson Foundation, Inc., Racine, WI.

    This article briefly describes a conference of Chinese and American women held to discuss womens' issues and promote mutual understanding between the two groups. The cultural exchange of information at the conference focused on discussion of the All China Womens' Federation (ACWF); the roles of women in China and the United States in the areas of…

  10. Indochinese Mutual Assistance Association: Time for a New Role.

    ERIC Educational Resources Information Center

    Shotts, Kermit F.

    The role of Indochinese self-help groups in the Refugee Resettlement Program is examined in this paper. Drawing on the literature dealing with Indochinese self-help groups, the paper reviews the factors which contribute to the formation of these groups, more commonly called Mutual Assistance Associations or MAAs. In addition, the value of MAAs as…

  11. 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…

  12. 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

  13. 77 FR 48566 - The Hartford Mutual Funds, Inc., et al.;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION The Hartford Mutual Funds, Inc., et al.; Notice of Application August 8, 2012. AGENCY: Securities and Exchange Commission (``Commission''). ACTION: Notice of an application under section 6(c) of...

  14. Mutual neutralization in low-energy H+ +F- collisions

    NASA Astrophysics Data System (ADS)

    Mezei, J. Zs.; Roos, J. B.; Shilyaeva, K.; Elander, N.; Larson, Å.

    2011-07-01

    The cross section for mutual neutralization in collisions between H+ and F- ions at low energies (E⩽10 eV) is calculated using a molecular close-coupling approach. Two different representations of the quasidiabatic potentials and couplings of HF are used. The effect of autoionization on the cross section is investigated. The coupled Schrödinger equation for the nuclear motion is solved using a numerical integration of the corresponding matrix Riccati equation and the cross section for mutual neutralization is computed from the asymptotic value of the logarithmic derivative of the radial wave function. The magnitude of the cross section for mutual neutralization in this reaction is small compared to other systems. This can be understood by the lack of avoided crossings at large internuclear distances. Resonant structures are found in the cross section and these are assigned with dominant angular momentum quantum number. The cross section for mutual neutralization in collisions of D+ and F- ions is also calculated.

  15. 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…

  16. Evolutionary origin of insect–Wolbachia nutritional mutualism

    PubMed Central

    Nikoh, Naruo; Hosokawa, Takahiro; Moriyama, Minoru; Oshima, Kenshiro; Hattori, Masahira; Fukatsu, Takema

    2014-01-01

    Obligate insect–bacterium nutritional mutualism is among the most sophisticated forms of symbiosis, wherein the host and the symbiont are integrated into a coherent biological entity and unable to survive without the partnership. Originally, however, such obligate symbiotic bacteria must have been derived from free-living bacteria. How highly specialized obligate mutualisms have arisen from less specialized associations is of interest. Here we address this evolutionary issue by focusing on an exceptional insect–Wolbachia nutritional mutualism. Although Wolbachia endosymbionts are ubiquitously found in diverse insects and generally regarded as facultative/parasitic associates for their insect hosts, a Wolbachia strain associated with the bedbug Cimex lectularius, designated as wCle, was shown to be essential for host’s growth and reproduction via provisioning of B vitamins. We determined the 1,250,060-bp genome of wCle, which was generally similar to the genomes of insect-associated facultative Wolbachia strains, except for the presence of an operon encoding the complete biotin synthetic pathway that was acquired via lateral gene transfer presumably from a coinfecting endosymbiont Cardinium or Rickettsia. Nutritional and physiological experiments, in which wCle-infected and wCle-cured bedbugs of the same genetic background were fed on B-vitamin–manipulated blood meals via an artificial feeding system, demonstrated that wCle certainly synthesizes biotin, and the wCle-provisioned biotin significantly contributes to the host fitness. These findings strongly suggest that acquisition of a single gene cluster consisting of biotin synthesis genes underlies the bedbug–Wolbachia nutritional mutualism, uncovering an evolutionary transition from facultative symbiosis to obligate mutualism facilitated by lateral gene transfer in an endosymbiont lineage. PMID:24982177

  17. An unbiased infrared H2 search for embedded flows from young stars in Orion A

    NASA Astrophysics Data System (ADS)

    Stanke, Thomas

    2001-04-01

    The presence of outflows, often in the form of well-collimated jets, is a phenomenon commonly associated with the birth of young stars. Emission from shock-excited molecular hydrogen at near-infrared wavelengths is one of the signposts of the presence of such an outflow, and generally can be observed even if the flow is obscured at optical wavelengths. In this thesis, I present the results of an unbiased, sensitive, wide-field search for flows from protostellar objects in the H2 v=1-0 S(1) line at a wavelength of 2.12 µm, covering a 1 square degree area of the Orion A giant molecular cloud. Further data covering a wide wavelength range are used to search for the driving sources of the flows. The aim of this work is to obtain a sample of outflows which is free from biases as far as possible, to derive the typical properties of the outflows, to search for evolutionary trends, and to examine the impact of outflows on the ambient cloud. The first result from this survey is that outflows are indeed common in star forming regions: more than 70 candidate jets are identified. Most of them have a fairly ill-defined morphology rather than a regular or symmetric structure, which is interpreted to be due to the turbulent, clumpy ambient medium into which the jets are propagating. The jets are randomly oriented. In particular, no alignment of the jets with the large scale ambient magnetic field is found, suggesting that the spin and symmetry axis in a protostellar object is determined by random, turbulent motions in the cloud. Candidate driving sources are identified for 49 jets, and their evolutionary stage and bolometric luminosity is estimated. The jet lengths and H2 luminosities evolve as a function of the age of the driving source: the jets grow quickly from zero length to a size of a few parsec and then slowly shorten again. The jets are very luminous early on and fade during the protostellar evolution. The evolution in length and H2 luminosity is attributed to an early

  18. Bandwidth-Efficient Mutually Cooperative Relaying with Spatially Coordinate-Interleaved Orthogonal Design

    NASA Astrophysics Data System (ADS)

    Ryu, Hyun-Seok; Park, Kyung-Mi; Lee, Hee-Soo; Kang, Chung-Gu

    This letter proposes a type of mutually cooperative relaying (MCR) scheme based on a spatially coordinate-interleaved orthogonal design (SCID), in which two cooperative users are spatially multiplexed without bandwidth expansion. It provides not only diversity gain (with order of two) as in the existing MCR scheme, but also additional coding gain. Our simulation results demonstrate that the proposed SCID scheme is useful for improving the uplink performance as long as one user can find another active user as a close neighbor that is simultaneously communicating with the same destination, e.g., a base station in the cellular network.

  19. Unbiased estimation in seamless phase II/III trials with unequal treatment effect variances and hypothesis-driven selection rules.

    PubMed

    Robertson, David S; Prevost, A Toby; Bowden, Jack

    2016-09-30

    Seamless phase II/III clinical trials offer an efficient way to select an experimental treatment and perform confirmatory analysis within a single trial. However, combining the data from both stages in the final analysis can induce bias into the estimates of treatment effects. Methods for bias adjustment developed thus far have made restrictive assumptions about the design and selection rules followed. In order to address these shortcomings, we apply recent methodological advances to derive the uniformly minimum variance conditionally unbiased estimator for two-stage seamless phase II/III trials. Our framework allows for the precision of the treatment arm estimates to take arbitrary values, can be utilised for all treatments that are taken forward to phase III and is applicable when the decision to select or drop treatment arms is driven by a multiplicity-adjusted hypothesis testing procedure. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. PMID:27103068

  20. SIRAH: a structurally unbiased coarse-grained force field for proteins with aqueous solvation and long-range electrostatics.

    PubMed

    Darré, Leonardo; Machado, Matías Rodrigo; Brandner, Astrid Febe; González, Humberto Carlos; Ferreira, Sebastián; Pantano, Sergio

    2015-02-10

    Modeling of macromolecular structures and interactions represents an important challenge for computational biology, involving different time and length scales. However, this task can be facilitated through the use of coarse-grained (CG) models, which reduce the number of degrees of freedom and allow efficient exploration of complex conformational spaces. This article presents a new CG protein model named SIRAH, developed to work with explicit solvent and to capture sequence, temperature, and ionic strength effects in a topologically unbiased manner. SIRAH is implemented in GROMACS, and interactions are calculated using a standard pairwise Hamiltonian for classical molecular dynamics simulations. We present a set of simulations that test the capability of SIRAH to produce a qualitatively correct solvation on different amino acids, hydrophilic/hydrophobic interactions, and long-range electrostatic recognition leading to spontaneous association of unstructured peptides and stable structures of single polypeptides and protein-protein complexes. PMID:26575407